publicationDate stringlengths 10 10 | abstract stringlengths 0 37.3k | title stringlengths 1 5.74k | doi stringlengths 11 47 ⌀ |
|---|---|---|---|
2021-01-19 | Low-pressure distillation has been proposed as a suitable technique for the recovery of carrier salt from molten salt reactor spent fuel. A closed-chamber distillation system, in which the pump is stopped and pressure-induced salt distillation is performed, was arranged for fluoride salt treatment. A stair-step optimization process was demonstrated to improve the recovery efficiency by up to 99%. The pressure change curve was feasible for estimating the distillation process, and a method for displaying the pressure value online in order to determine the end-point was also developed. The decontamination factor of Nd in the condensate salt was deduced to be greater than 100 with 1 wt% NdF 3 –FLiNaK distillation. The optimal conditions developed in this study showed a high recovery ratio for the fluoride carrier salt and a high separation efficiency for rare earth products. | Process optimization of a closed-chamber distillation system for the recovery of FLiNaK molten salt | 10.1007/s41365-020-00843-1 |
2021-01-14 | Background Low-temperature severely affects the growth and development of chrysanthemum which is one kind of ornamental plant well-known and widely used in the world. Lysine crotonylation is a recently identified post-translational modification (PTM) with multiple cellular functions. However, lysine crotonylation under low-temperature stress has not been studied. Results Proteome-wide and lysine crotonylation of chrysanthemum at low-temperature was analyzed using TMT (Tandem Mass Tag) labeling, sensitive immuno-precipitation, and high-resolution LC-MS/MS. The results showed that 2017 crotonylation sites were identified in 1199 proteins. Treatment at 4 °C for 24 h and − 4 °C for 4 h resulted in 393 upregulated proteins and 500 downregulated proteins (1.2-fold threshold and P < 0.05). Analysis of biological information showed that lysine crotonylation was involved in photosynthesis, ribosomes, and antioxidant systems. The crotonylated proteins and motifs in chrysanthemum were compared with other plants to obtain orthologous proteins and conserved motifs. To further understand how lysine crotonylation at K136 affected APX (ascorbate peroxidase), we performed a site-directed mutation at K136 in APX. Site-directed crotonylation showed that lysine decrotonylation at K136 reduced APX activity, and lysine complete crotonylation at K136 increased APX activity. Conclusion In summary, our study comparatively analyzed proteome-wide and crotonylation in chrysanthemum under low-temperature stress and provided insights into the mechanisms of crotonylation in positively regulated APX activity to reduce the oxidative damage caused by low-temperature stress. These data provided an important basis for studying crotonylation to regulate antioxidant enzyme activity in response to low-temperature stress and a new research ideas for chilling-tolerance and freezing-tolerance chrysanthemum molecular breeding. | Proteome-wide and lysine crotonylation profiling reveals the importance of crotonylation in chrysanthemum (Dendranthema grandiforum) under low-temperature | 10.1186/s12864-020-07365-5 |
2021-01-14 | We study various properties of the soft modes in the N $$ \mathcal{N} $$ = 2 supersymmetric SYK model. | Soft modes in
N
$$ \mathcal{N} $$
= 2 SYK model | 10.1007/JHEP01(2021)082 |
2021-01-13 | This paper presents the results of an experimental investigation that focused on the failure properties of asphalt binders at low temperatures. A novel test method was developed, based on the use of the dynamic shear rheometer equipped with 4 mm parallel plates. The method entails the application of constant shear strain rates at various temperatures until failure. Test data are modelled by means of the elastic-viscoelastic correspondence principle and by thereafter referring to the shear stress at failure, to a purposely defined brittleness index and to a critical brittleness temperature. Results discussed in the paper, which refer to a preliminary set of experimental data, indicate that the proposed methodology may be very effective in evaluating and comparing low temperature failure properties of asphalt binders of various types and origins. | A novel methodology for the evaluation of low temperature failure properties of asphalt binders | 10.1617/s11527-020-01610-9 |
2021-01-09 | Background Diabetic foot infection (DFI) is a limb- and life-threatening complication for diabetic patients needing immediate and comprehensive treatment. Early referral of DFI patients to a diabetic foot center is recommended but there appears limited validated evidence, with the association between referral time and clinical outcomes of limb- preservation or in-hospital mortality still lacking. Methods This retrospective research studied consecutive type 2 diabetic patients with DFI treated at the major diabetic foot center in Taiwan from 2014 to 2017. Six hundred and sixty-eight patients presented with limb-threatening DFI. After stratifying their referral days into quartiles, the demographic information and clinical outcomes were analyzed. Results One hundred and seventy-two patients were placed in the first quartile (Q1) with less than 9 days of referral time; 164 in the second quartile (Q2) with 9-21 days; 167 in the third quartile (Q3) with 21-59 days; and 165 in the fourth quartile (Q4) with >59 days. End-stage renal disease (ESRD), major adverse cardiac events (MACE) and peripheral arterial disease (PAD) were noted as being higher in the Q4 group compared with the Q1 group (25.45% vs 20.35% in ESRD, 47.27% vs 26.16% in MACE and 78.79% vs 52.33% in PAD respectively). The Q1 group had more patients presenting with systemic inflammatory responsive syndrome (SIRS) (29.07% in Q1 vs 25.45% in Q4 respectively, P =0.019). Regarding poor outcome (major lower-extremity amputation (LEA) or in-hospital mortality), the Q4 group had 21.21% of patients in this category and the Q1 group had 10.47%. The odds ratio of each increased referral day on poor prognosis was 1.006 with 95% confidence interval 1.003–1.010 ( P =<0.001). In subgroups, the impact on poor prognosis by day was most obvious in patients with SIRS (OR 1.011, 95% CI 1.004–1.018, P =0.003) and those with PAD (OR 1.004, 95% CI 1.001–1.008, P =0.028). Conclusions The deferred referral of DFI patients to the diabetic foot center might be associated with poor treatment outcome either in major LEA or mortality, particularly in patients with SIRS or PAD. Both physician and patient awareness of disease severity and overcoming the referral barrier is suggested. Trial registration Not applicable. | The analysis for time of referral to a medical center among patients with diabetic foot infection | 10.1186/s12875-020-01363-y |
2021-01-08 | Background The inflammatory profiles of patients with acute and chronic nonspecific low back pain (LBP) patients are distinct. Spinal manipulative therapy (SMT) has been shown to modulate the production of nociceptive chemokines differently in these patient cohorts. The present study further investigates the effect(s) of SMT on other inflammatory mediators in the same LBP patient cohorts. Methods Acute ( n = 22) and chronic ( n = 25) LBP patients with minimum pain scores of 3 on a 10-point numeric scale, and asymptomatic controls ( n = 24) were recruited according to stringent exclusion criteria. Blood samples were obtained at baseline and after 2 weeks during which patients received 6 SMTs in the lumbar or lumbosacral region. The in vitro production of tumor necrosis factor (TNFα), interleukin-1 β (IL-1β), IL-6, IL-2, interferon ɣ (IFNɣ), IL-1 receptor antagonist (IL-1RA), TNF soluble receptor type 2 (sTNFR2) and IL-10 was determined by specific immunoassays. Parametric as well as non-parametric statistics (PAST 3.18 beta software) was used to determine significance of differences between and within study groups prior and post-SMT. Effect size (ES) estimates were obtained using Cohen’s d. Results Compared with asymptomatic controls, SMT-related change scores were significant ( P = 0.03–0.01) in reducing the production levels of TNFα in both patient cohorts and those of IL-6, IFNɣ and sTNFR2 ( P = 0.001–0.02) in patients with chronic LBP. Above-moderate to large ES ( d > 0.6–1.4) was observed for these mediators. Compared with respective baselines, a significant post-SMT reduction ( P = 0.01) of IL-6 production was detected only in patients with chronic LBP while a significant increase of IL-2 production ( P = 0.001 vs. control, and P = 0.004 vs. chronic LBP group) and a large ES ( d = 0.87) were observed in patients with acute LBP. Pain and disability scores declined significantly ( P < 0.001) in all LBP patients, and were positively correlated ( P = 0.03) with IFNɣ and IL-2 levels in the acute LBP cohort. Conclusion The short course of SMT treatments of non-specific LBP patients resulted in significant albeit limited and diverse alterations in the production of several of the mediators investigated in this study. This exploratory study highlights the potential of SMT to modulate the production of inflammatory components in acute and chronic non-specific LBP patients and suggests a need for further, randomized controlled clinical trials in this area. Trial registration This study was prospectively registered April 2012 with Clinical Trials.gov ( #NCT01766141 ). https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S0003ZIL&selectaction=Edit&uid=U0001V74&ts=2&cx=-axvqtg | Effects of spinal manipulative therapy on inflammatory mediators in patients with non-specific low back pain: a non-randomized controlled clinical trial | 10.1186/s12998-020-00357-y |
2021-01-07 | Background Globally, approximately 15 million babies are born preterm every year. Complications of prematurity are the leading cause of under-five mortality. There is overwhelming evidence from low, middle, and high-income countries supporting kangaroo mother care (KMC) as an effective strategy to prevent mortality in both preterm and low birth weight (LBW) babies. However, implementation and scale-up of KMC remains a challenge, especially in lowincome countries such as Ethiopia. This formative research study, part of a broader KMC implementation project in Southern Ethiopia, aimed to identify the barriers to KMC implementation and to devise a refined model to deliver KMC across the facility to community continuum. Methods A formative research study was conducted in Southern Ethiopia using a qualitative explorative approach that involved both health service providers and community members. Twenty-fourin-depth interviewsand 14 focus group discussions were carried out with 144study participants. The study applied a grounded theory approach to identify,examine, analyse and extract emerging themes, and subsequently develop a model for KMC implementation. Results Barriers to KMC practice included gaps in KMC knowledge, attitude and practices among parents of preterm and LBW babies;socioeconomic, cultural and structural factors; thecommunity’s beliefs and valueswith respect to preterm and LBW babies;health professionals’ acceptance of KMC as well as their motivation to implement practices; and shortage of supplies in health facilities. Conclusions Our study suggests a comprehensive approach with systematic interventions and support at maternal, family, community, facility and health care provider levels. We propose an implementation model that addresses this community to facility continuum. | Barriers for kangaroo mother care (KMC) acceptance, and practices in southern Ethiopia: a model for scaling up uptake and adherence using qualitative study | 10.1186/s12884-020-03409-6 |
2021-01-06 | Background The preventive and therapeutic medical utilization of this plant is an age-long practice across the globe. This study aimed to validate the impact of dark purple blossoms of basil ( Ocimum basilicum L. ) aqueous extract at low temperature (0 °C) mediated mitochondrial fission contributed to induced apoptosis in human breast cancer cells. Methods Fresh blossoms were extracted at low temperature (0 °C) using a watery solvent. Human MCF7 breast cancer cells were then treated with 3 separate fluctuated concentrations of 0, 50, 150 and 250 µg/mL for 24 and 48 h. Results The outcomes demonstrated the presence of anthocyanins, anthraquinones, tannins, reducing sugars, glycosides, proteins, amino acids, flavonoids and volatile oils and nonappearance of Terpinoids and alkaloids. Contrastingly, frail presence of steroids in basil blossoms aqueous concentrate was noted. In addition, the results from a phytochemical subjective examination of basil ( Ocimum basilicum L. ) blossoms aqueous extract demonstrated that most of the credited natural impacts containing more remarkable contents of antioxidants and anticancer compounds in basil blossoms aqueous extract. Moreover, the restraint of glucose take-up was alleviated mediated by a dose-dependent manner in MCF7 cells with basil ( Ocimum basilicum L. ) blossoms aqueous extract inducted for 24 h, resulting in mitochondrial fission. Conclusion This is the first study that shows the impact of the aqueous extract of basil ( Ocimum basilicum L. ) blossoms was extracted at low temperature (0℃/6 h) underlined high amounts of flavonoids and phenolic compounds bearing more anticancer and antioxidant activities compared to another aqueous extract (using boiled water solvent) and alcoholic extracts. | Low-temperature extracts of Purple blossoms of basil (Ocimum basilicum L.) intervened mitochondrial translocation contributes prompted apoptosis in human breast cancer cells | 10.1186/s40659-020-00324-0 |
2021-01-06 | Background Globally, 15 million neonates are born prematurely every year, over half in low income countries (LICs). Premature and low birth weight neonates have a higher risk of intraventricular haemorrhage (IVH). There are minimal data regarding IVH in sub-Saharan Africa. This study aimed to examine the incidence, severity and timing of and modifiable risk factors for IVH amongst low-birth-weight neonates in Uganda. Methods This is a prospective cohort study of neonates with birthweights of ≤2000 g admitted to a neonatal unit (NU) in a regional referral hospital in eastern Uganda. Maternal data were collected from interviews and medical records. Neonates had cranial ultrasound (cUS) scans on the day of recruitment and days 3, 7 and 28 after birth. Risk factors were tabulated and are presented alongside odds ratios (ORs) and adjusted odds ratios (aORs) for IVH incidence. Outcomes included incidence, timing and severity of IVH and 28-day survival. Results Overall, 120 neonates were recruited. IVH was reported in 34.2% of neonates; 19.2% had low grade (Papile grades 1–2) and 15% had high grade (Papile grades 3–4). Almost all IVH (90.2%) occurred by day 7, including 88.9% of high grade IVH. Of those with known outcomes, 70.4% (81/115) were alive on day 28 and survival was not associated with IVH. We found that vaginal delivery, gestational age (GA) < 32 weeks and resuscitation in the NU increased the odds of IVH. Of the 6 neonates who received 2 doses of antenatal steroids, none had IVH. Conclusion In this resource limited NU in eastern Uganda, more than a third of neonates born weighing ≤2000 g had an IVH and the majority of these occurred by day 7. We found that vaginal birth, earlier gestation and need for resuscitation after admission to the NU increased the risk of IVH. This study had a high rate of SGA neonates and the risk factors and relationship of these factors with IVH in this setting needs further investigation. The role of antenatal steroids in the prevention of IVH in LICs also needs urgent exploration. | Intraventricular haemorrhage in a Ugandan cohort of low birth weight neonates: the IVHU study | 10.1186/s12887-020-02464-4 |
2021-01-06 | Background Lysosomal storage disorders (LSDs) are rare genetic disorders, with heterogeneous clinical manifestations and severity. Treatment options, such as enzyme replacement therapy (ERT), substrate replacement therapy, and pharmacological chaperone therapy, are available for several LSDs, including Gaucher disease (GD), Fabry disease (FD), and Hunter syndrome (mucopolysaccharidosis type II [MPS II]). However, patients in some countries face challenges accessing treatments owing to limited availability of locally licensed, approved drugs. Methods The Takeda LSD Charitable access program aims to meet the needs of individuals with GD, FD or MPS II with the greatest overall likelihood of benefit, in selected countries, through donation of ERT to nonprofit organizations, and support for medical capacity-building as well as family support via independent grants. Long-term aims of the program are to establish sustainable healthcare services delivered by local healthcare providers for patients with rare metabolic diseases. Patients receiving treatment through the program are monitored regularly, and their clinical data and progress are reviewed annually by an independent medical expert committee (MEC). The MEC also selects patients for enrollment completely independent from the sponsoring company. Results As of 31 August, 2019, 199 patients from 13 countries were enrolled in the program; 142 with GD, 41 with MPS II, and 16 with FD. Physicians reported improvements in clinical condition for 147 (95%) of 155 patients with follow-up data at 1 year. Conclusions The response rate for follow-up data at 1 year was high, with data collected for > 90% of patients who received ERT through the program showing clinical improvements in the majority of patients. These findings suggest that the program can benefit selected patients previously unable to access disease-specific treatments. Further innovative solutions and efforts are needed to address the challenges and unmet needs of patients with LSDs and other rare diseases around the world. | A charitable access program for patients with lysosomal storage disorders in underserved communities worldwide | 10.1186/s13023-020-01645-9 |
2021-01-06 | Driving stress can impact the driving performance that has an impact on the overall driving experiences. It is a vital area to focus on when the traffic scenario is challenging in terms of having traffic congestion, unruly drivers, and a lack of law enforcement. In Bangladesh, these issues are frequent on the roads. That is why we looked at self-reported stress scores of professional drivers, their personality analysis and conducted mixed-method (quantitative and qualitative) user studies that provided us a clear indication of driving stress. Then the findings motivated us to design and develop a low-cost real-time stress measurement wearable through human-centered computing, users’ feedback, and experiences. This wearable unit can understand bodily stress from physiological factors using Heart Rate Variability along with road conditions. This technology can help in supporting drivers in increasing self-awareness regarding driving stress, which will have a positive impact on drivers’ wellbeing and overall driving performance. | Understanding self-reported stress among drivers and designing stress monitor using heart rate variability | 10.1007/s41233-020-00043-0 |
2021-01-05 | An earth air heat exchanger (EAHE) has advantages of its simplicity, easy implementation and low operating cost. The EAHE system is found less expensive for cooling and heating of buildings in severe climates. In this research paper, efforts have been made to analyze the accomplishment of a low-cost cooling system of outdoor air for the hot-dry & hot-humid climate. The effect of velocity, length and depth on the cooling potential of the system is studied at the inlet and outlet of the pipe. The novelty of this research is that enormous enhancement of the cooling potential has been observed in hot-humid climate than hot-dry climate, which is not available in previous studies. The results show that the maximum cooling potential in hot-dry climate is found 5643 kWh, 7375 kWh, 8939 kWh for the EAHE length of 15 m, 30 m and 45 m, respectively, corresponding to the velocity 2.5 m s −1 and depth 1.5 m. Whereas in a hot-humid climate, maximum cooling potential is achieved 13,373 kWh, 20,134 kWh and 24,080 kWh with a length of 15 m, 30 m and 45 m, respectively, for the given velocity and depth. | Evaluation of the Cooling Potential of Earth Air Heat Exchanger Using Concrete Pipes | 10.1007/s10765-020-02774-w |
2021-01-05 | Background The accumulation of lipid-laden macrophages, foam cells, within sub-endothelial intima is a key feature of early atherosclerosis. Siglec-E, a mouse orthologue of human Siglec-9, is a sialic acid binding lectin predominantly expressed on the surface of myeloid cells to transduce inhibitory signal via recruitment of SH2-domain containing protein tyrosine phosphatase SHP-1/2 upon binding to its sialoglycan ligands. Whether Siglec-E expression on macrophages impacts foam cell formation and atherosclerosis remains to be established. Methods ApoE-deficient (apoE −/− ) and apoE/Siglec-E-double deficient (apoE −/− /Siglec-E −/− ) mice were placed on high fat diet for 3 months and their lipid profiles and severities of atherosclerosis were assessed. Modified low-density lipoprotein (LDL) uptake and foam cell formation in wild type (WT) and Siglec-E −/− - peritoneal macrophages were examined in vitro. Potential Siglec-E-interacting proteins were identified by proximity labeling in conjunction with proteomic analysis and confirmed by coimmunoprecipitation experiment. Impacts of Siglec-E expression and cell surface sialic acid status on oxidized LDL uptake and signaling involved were examined by biochemical assays. Results Here we show that genetic deletion of Siglec-E accelerated atherosclerosis without affecting lipid profile in apoE −/− mice. Siglec-E deficiency promotes foam cell formation by enhancing acetylated and oxidized LDL uptake without affecting cholesterol efflux in macrophages in vitro. By performing proximity labeling and proteomic analysis, we identified scavenger receptor CD36 as a cell surface protein interacting with Siglec-E. Further experiments performed in HEK293T cells transiently overexpressing Siglec-E and CD36 and peritoneal macrophages demonstrated that depletion of cell surface sialic acids by treatment with sialyltransferase inhibitor or sialidase did not affect interaction between Siglec-E and CD36 but retarded Siglec-E-mediated inhibition on oxidized LDL uptake. Subsequent experiments revealed that oxidized LDL induced transient Siglec-E tyrosine phosphorylation and recruitment of SHP-1 phosphatase in macrophages. VAV, a downstream effector implicated in CD36-mediated oxidized LDL uptake, was shown to interact with SHP-1 following oxidized LDL treatment. Moreover, oxidized LDL-induced VAV phosphorylation was substantially lower in WT macrophages comparing to Siglec-E −/− counterparts. Conclusions These data support the protective role of Siglec-E in atherosclerosis. Mechanistically, Siglec-E interacts with CD36 to suppress downstream VAV signaling involved in modified LDL uptake. | Siglec-E retards atherosclerosis by inhibiting CD36-mediated foam cell formation | 10.1186/s12929-020-00698-z |
2021-01-05 | One of the most striking but mysterious properties of the sinh-Gordon model (ShG) is the b → 1/ b self-duality of its S -matrix, of which there is no trace in its Lagrangian formulation. Here b is the coupling appearing in the model’s eponymous hyperbolic cosine present in its Lagrangian, cosh( bϕ ). In this paper we develop truncated spectrum methods (TSMs) for studying the sinh-Gordon model at a finite volume as we vary the coupling constant. We obtain the expected results for b ≪ 1 and intermediate values of b , but as the self-dual point b = 1 is approached, the basic application of the TSM to the ShG breaks down. We find that the TSM gives results with a strong cutoff E c dependence, which disappears according only to a very slow power law in E c . Standard renormalization group strategies — whether they be numerical or analytic — also fail to improve upon matters here. We thus explore three strategies to address the basic limitations of the TSM in the vicinity of b = 1. In the first, we focus on the small-volume spectrum. We attempt to understand how much of the physics of the ShG is encoded in the zero mode part of its Hamiltonian, in essence how ‘quantum mechanical’ vs ‘quantum field theoretic’ the problem is. In the second, we identify the divergencies present in perturbation theory and perform their resummation using a supra-Borel approximate. In the third approach, we use the exact form factors of the model to treat the ShG at one value of b as a perturbation of a ShG at a different coupling. In the light of this work, we argue that the strong coupling phase b > 1 of the Lagrangian formulation of model may be different from what is naïvely inferred from its S -matrix. In particular, we present an argument that the theory is massless for b > 1. | Approaching the self-dual point of the sinh-Gordon model | 10.1007/JHEP01(2021)014 |
2021-01-05 | Purpose A fully electrified transport chain offers considerable potential for CO 2 savings. In this paper, we examine the conditions necessary to introduce a fully electrified, large-scale, high-speed rail freight transport system in Europe in addition to high-speed passenger trains, aiming to shift goods transport from road to rail. We compare a novel high-speed rail freight concept with road-based lorry transport for low-density high value goods to estimate the potential for a modal shift from road to rail in 2030. Methods To characterize the impacts of different framework conditions, a simulation tool was designed as a discrete choice model, based on random utility theory, with integrated performance calculation assessing the full multimodal transport chain regarding costs, emissions and time. It was applied to a European reference scenario based on forecast data for freight traffic in 2030. Results We show that high-speed rail freight is about 70% more expensive than the conventional lorry but emits 80% less CO 2 emissions for the baseline parameter setting. The expected mode share largely depends on the cargo’s value of time, while the implementation of a CO 2 -tax of 100 EUR/tCO 2 eq has an insignificant impact. The costs of handling goods and the infrastructure charges are highly influential variables. Conclusion High-speed rail track access charges are a suitable political instrument to create a level playing field between the transport modes and internalize external costs of freight transport. With the given access charge structure, a reduction of the maximum operating speed to 160 km/h has a positive impact on the expected mode share of rail transport while it still reacts positively to a wide range of the cargo’s time sensitivity (compared to a maximum operating speed of 350 km/h). The flexibility of rail freight’s operating speed is important for an effective implementation. Further research should concentrate on time- and cost-efficient transhipment terminals as they have a significant impact on transport performance. | The potential of high-speed rail freight in Europe: how is a modal shift from road to rail possible for low-density high value cargo? | 10.1186/s12544-020-00453-3 |
2021-01-04 | Background To assess the prevalence and demographics of lower eyelid epiblepharon in Chinese preschool children and to evaluate its association with refractive errors. Methods In this population-based, cross-sectional study, a total of 3170 children aged 3 to 6 years from Beijing, China underwent examinations including weight, height, cycloplegic autorefraction and slit-lamp examination of external eyes. The prevalence of lower eyelid epiblepharon in preschool children was evaluated and its association with age, sex, body mass index (BMI), and refractive errors was analyzed using logistic regression analysis. Results The prevalence of lower eyelid epiblepharon was 26.2%, which decreased with age, with prevalence in 3-, 4-, 5-, and 6-year-olds of 30.6, 28.0, 15.0, and 14.3%, respectively. Boys had a higher risk of having epiblepharon than girls (OR = 1.41; 95%CI, (1.20–1.66)) and no significant correlation was detected between BMI and epiblepharon after adjusting for age and sex ( p = 0.062). Epiblepharon was significantly associated with a higher risk of refractive errors, including astigmatism (OR = 3.41; 95% CI, (2.68–4.33)), myopia (OR = 3.55; 95% CI, (1.86–6.76)), and hyperopia (OR = 1.53; 95% CI, (1.18–1.99)). Conclusions There is a high prevalence of lower eyelid epiblepharon in Chinese preschool children, particularly among boys and younger children. Preschoolers with lower eyelid epiblepharon are subject to a higher risk of developing astigmatism, myopia, and hyperopia, than those without. Increased attention should be paid to this eyelid abnormality in the preschool population. | The prevalence of lower eyelid epiblepharon and its association with refractive errors in Chinese preschool children: a cross-sectional study | 10.1186/s12886-020-01749-7 |
2021-01-04 | Background Household air pollution exposure is linked with over 3.5 million premature deaths every year, ranking highest among environmental risk factors globally. Children are uniquely vulnerable and sensitive to the damaging health effects of household air pollution which includes childhood acute lower respiratory infection (ALRI). The use of improved cookstoves has been widely encouraged to reduce these health burdens. It is, however, unclear as to whether it is possible to prevent household air pollution-related disease burdens with biomass-fuelled improved cookstove intervention and the evidence regarding its child health effect still attracts wide debate. Therefore, we investigated the child health effect of improved baking stove intervention compared with the continuation of the open burning traditional baking stove. Methods A cluster-randomized controlled trial was conducted to assess the health effect of improved baking stove intervention. A total of 100 clusters were randomly allocated to both arms at a 1:1 ratio, and a total of four follow-up visits were carried out within 1 year immediately after the delivery of the intervention to all households allocated into the intervention arm. Data were analyzed in SPSS-22, and the intervention effect was estimated using a Generalized Estimating Equations modeling approach among the intention-to-treat population. Results A total of 5508 children were enrolled in the study across 100 randomly selected clusters in both arms, among which data were obtained from a total of 5333 participants for at least one follow-up visit which establishes the intention-to-treat population dataset. The intervention was not found to have a statistically significant effect on the longitudinal childhood ALRI with an estimated odds ratio of 0.95 (95% CI: 0.89–1.02). Nevertheless, the longitudinal change in childhood ALRI was significantly associated with age, baseline childhood ALRI, location of cooking quarter, secondary stove type and frequency of baking event measured at baseline. Conclusions We found no evidence that an intervention comprising biomass-fuelled improved baking stove reduced the risk of childhood ALRI compared with the continuation of an open burning traditional baking stove. Therefore, effective cooking solutions are needed to avert the adverse health effect of household air pollution, particularly, childhood ALRI. Trial registration The trial was registered on August 2, 2018 at clinical trials.gov registry database (registration identifier number: NCT03612362). | Effect of improved cookstove intervention on childhood acute lower respiratory infection in Northwest Ethiopia: a cluster-randomized controlled trial | 10.1186/s12887-020-02459-1 |
2021-01-01 | Thermal spray processes are relatively mature technologies widely used in industry. They mostly involve the introduction of either particles (in the tens of micrometers size range) into the high-energy gas stream where they are, except for cold spray, accelerated and heated over or below their meting point, or wires, cored wires, rods, cords, which have their tip melted and atomized. The thermal and kinetic energy content of the ductile particles or droplets impinging on the substrate can widely vary with the process used. Moreover, for metals or alloys or composites sprayed in air, high process temperatures tend to increase the in-flight particle oxidation, increasing the oxide content embedded into the coating. The coating is formed by ductile particles or droplets flattening to form splats, which layering forms the coating. Thus, the coating formation depends also strongly on substrate surface composition, microstructure, roughness, and pollution. This chapter starts with the physical and chemical description of substrates with the drastic influence of the oxide layer and the mean to get rid of adsorbates and condensates. Then the impact of a single ductile particle (metal, alloy, cermet, ceramic, polymer) or a droplet is considered first on a smooth surface and then on a rough one. The way parameters characterizing flattening (Reynolds, Weber, Sommerfeld numbers), must be calculated to fit with experiments is discussed, as well as the impact direction. Coating formation is discussed from splats layering with the formation of beads and passes and the importance and means, such as robots and cooling devices, to control the coating temperature during its formation. The different residual stresses formed during spraying are presented with their influence on coating adhesion-cohesion. | Conventional Coating Formation | 10.1007/978-3-030-70672-2_15 |
2021-01-01 | This chapter introduces the inert anode and points out that the inert anode can overcome the shortcomings of the electrolytic cells and carbon anode. The development, advantages, and disadvantages of various inert anodes and electrolytic cells are introduced. This chapter also focuses on the cermet inert anode developed by American Aluminum Company (Alcoa), which is considered to be the best and most promising inert anode. In addition, the shortcomings of cermet inert anode and the problems that hinder its popularization and application in the aluminum industry are introduced. | Aluminum Electrolytic Inert Anode | 10.1007/978-3-030-28913-3_3 |
2021-01-01 | This chapter presents an innovative framework for the application of machine learning and data analytics for the identification of alloys or composites exhibiting certain desired properties of interest. The main focus is on alloys and composites with large composition spaces for structural materials. Such alloys or composites are referred to as high-entropy materials (HEMs) and are here presented primarily in the context of structural applications. For each output property of interest, the corresponding driving (input) factors are identified. These input factors may include the material composition, heat treatment, manufacturing process, microstructure, temperature, strain rate, environment, or testing mode. The framework assumes the selection of an optimization technique suitable for the application at hand and the data available. Physics-based models are presented, such as for predicting the ultimate tensile strength (UTS) or fatigue resistance. We devise models capable of accounting for physics-based dependencies. We factor such dependencies into the models as a priori information. In case that an artificial neural network (ANN) is deemed suitable for the applications at hand, it is suggested to employ custom kernel functions consistent with the underlying physics, for the purpose of attaining tighter coupling, better prediction, and for extracting the most out of the – usually limited – input data available. | Machine Learning and Data Analytics for Design and Manufacturing of High-Entropy Materials Exhibiting Mechanical or Fatigue Properties of Interest | 10.1007/978-3-030-77641-1_4 |
2021-01-01 | DC plasma spraying stands out as one of the most widely used thermal spray techniques for a broad range of applications including tribological and wear resistance, corrosion and/or oxidation resistance, thermal protection, biomedical applications, and the deposition of free-standing spray-formed parts. The technology is based on a simple concept of in-flight melting of the material to be sprayed injected into a plasma stream in the form of fine dispersed powder, solution or suspension, followed by the deposition of the molten droplets on the substrate to be sprayed on which they form splats freezing on impact. The coating is thus formed through the accumulation of successive layer of splats which can grow to hundreds of micrometers thick and more. Because of the intensive R&D efforts in this field over the past few decades, the presentation of this technology has been split into two complementary chapters, with “Chapter 8 DC Plasma Spraying –Fundamentals” dedicated to a discussion of basic concepts behind the technology. The present chapter follows up with a description of DC Plasma Spray technology under a wide range of conditions including Atmospheric Plasma Spraying (APS), Controlled Atmosphere Plasma Spraying (CAPS), Vacuum Plasma Spraying (VPS), and Ultra-Low-Pressure Plasma Spraying (ULPPS). Detailed discussions of substrate preparation, coating formation, and coating characterization are covered in Part III, while process integration including powder/wire or cord preparation, instrumentation, industrial applications, and process economics are covered in Part IV of this book. | DC Plasma Spraying, Process Technology | 10.1007/978-3-030-70672-2_9 |
2021-01-01 | Organic field-effect transistors (OFETs)-based flexible temperature sensors have been developed by using a ferroelectric material as a temperature-sensitive dielectric layer. An OFET contains layers of different materials grown in a multilayer structure. The performance of the device crucially depends on the semiconductor/dielectric interfaces. In this article, we have discussed how to optimize the growth of various layers used in the device fabrication to achieve better charge conduction in the semiconductor/dielectric interface. We have used a bilayer dielectric system with hexagonal barium titanate nanocrystals (h-BTNCs) in the amorphous phase as one of the layers, which is temperature-sensitive. Highly flexible 10 μm and 100 μm polyethylene terephthalate (PET) are used as substrates. The devices show ultrafast response with 24 ms and its sensing temperature over a range from 20 °C to 45 °C. The sensors are highly stable around body temperature and work under various extreme conditions, such as underwater, solutions of different pH, and various salt concentrations. The OFETs-based sensors are suitable for wearable healthcare applications, where continuous monitoring of body temperature at an ultrafast rate with high precession is necessary. | Flexible Organic Field-Effect Transistors Using Barium Titanate as Temperature-Sensitive Dielectric Layer | 10.1007/978-3-030-74073-3_5 |
2021-01-01 | Materials are a vitally important issue in the development of human society, and the development of each new material could provide great support for scientific and technological progress and human development. Also, from the perspective of human development in the field of metal materials, the complexity of the elemental composition in alloys has been increasing steadily with time as illustrated, meanwhile the mixing entropy of the alloy system has also been improved, such as the super alloys and stainless steels, which are already in the range of medium-entropy alloys from the perspective of entropy value (1.0R ≤ ΔS mix < 1.5R) (R is the ideal gas constant) (Zhang et al., Sci China Mater 61: 2–22, 2018, Yan et al. Metall Mater Trans A 52: 2111–2122, 2021). The concept of high-entropy alloys (HEAs) was proposed by Professor Yeh in 2004 (Yeh et al., Adv Eng Mater 6: 299–303, 2004), which broke the design criteria of traditional metallic materials and provided us with new design ideas and concepts for the development of new materials. After more than 15 years of research work on HEAs, many results have been obtained in this field of scientific exploration. The results of these endeavors have indicated that HEAs exhibit many desirable properties, such as high-temperature resistance, break the trade-off between strength and toughness, irradiation resistance, excellent low-temperature performance (low-stacking fault energy with face-centered cubic structure), which have also been discovered (Zhang et al., Prog Mater Sci 61: 1–93, 2014, Sci China Mater, 61: 2–22, 2018). In this chapter, we will focus on the future research directions, prospects, and potential future applications of high-entropy materials (HEMs). | Future Research Directions and Applications for High-Entropy Materials | 10.1007/978-3-030-77641-1_14 |
2021-01-01 | Fe–Mn–Al–C steels, previously developed in the 1950s for replacing Fe–Cr–Ni steels as oxidation or corrosion resistance steels or cryogenic temperature steels, are currently revisited due to two reasons. From an engineering point of view, the specific weight of the steels is reduced when a large amount of light element Al is added, resulting in the so-called low-density or lightweight steels. From an academic point of view, the metallurgical theories of the steels are not well established. The low-density or lightweight steels are expected to have potential applications for structural parts in the automotive industry. This chapter discusses the basic metallurgy, processing strategies, strengthening mechanisms and mechanical properties of these steels from the published literature over a period of many years and suggests avenues for future applications of these alloys in the automotive sector. | Low-Density Steels | 10.1007/978-3-030-53825-5_6 |
2021-01-01 | Residual stress and distortion of welded specimens are issues when it comes to geometrical requirements. The surrounding material prevents the dilatation associated with transformation in the area of heat input resulting in residual stress and distortion due to thermal contraction. In the past few years, low transformation temperature (LTT) material was successfully used as filler wire to reduce residual stress as well as distortion in the weld seam in arc welding processes. High alloy Fe-based filler materials with levels of chromium and nickel ensure a martensitic transformation at reduced temperatures in a low alloy base material. The LTT properties counteract the accumulation of stresses due to thermal contraction with compressive stresses that develop within the transformed region. This work used a high alloy base material in combination with a low alloy filler wire resulting in a microstructure that shows the same properties as LTT weld metals. This in situ alloying allows for an alloy composition tailored to the process. In order to provide a point of reference, comparable welds were made using conventional high alloy filler wire. As a result, the distortion and longitudinal residual stress was significantly reduced compared to welding with conventional filler wire. | Reduction of distortion by using the low transformation temperature effect for high alloy steels in electron beam welding | 10.1007/s40194-020-00993-1 |
2021-01-01 | Temperature and loading time influence the viscoelastic behavior of bitumen. The present study aimed to compare the results of some analyses including Burger model, relaxation modulus, dissipation energy ratio, statistical analysis of ANOVA and artificial neural networks (ANN) and to investigate the viscoelastic behavior of bitumen modified with nano-CaCO 3 (NCCO) and ethylene-vinyl acetate (EVA). To this end, the Bending Beam Rheometer (BBR) tests were conducted on NCCO- and EVA-modified bitumen at various temperatures. According to the previous studies, NCCO was utilized for 4% and 6% weight of neat bitumen and the BBR test was conducted at low temperatures of −6 and −12°C. In addition, EVA was utilized for 6% weight of neat bitumen and the BBR test was conducted at low temperatures of −6, −12 and −18°C. Hence, results of four models showed that EVA-modified bitumen could improve the viscoelastic behavior of bitumen in low temperatures and NCCO had a negligible effect on improving bitumen. Finally, results of the Burger model, relaxation modulus, and dissipation energy ratio were compared and based on these results, the relaxation modulus and dissipation energy ratio were more accurate than the Burger model. Additionally, results of the statistical analysis of ANOVA were weaker than the artificial neural networks (ANN) method. | Comparison of BBR results of EVA polymer and nano-CaCO3-modified bitumen using burger model, relaxation modulus, dissipation energy ratio, ANOVA, and artificial neural networks | 10.1007/s42947-020-0006-3 |
2021-01-01 | Low-temperature stress (LTS) is one of the major abiotic stresses that affect crop growth and ultimately decrease grain yield. The development of rice varieties with low-temperature stress tolerance has been a severe challenge for rice breeders for a long time. The lack of consistency of the quantitative trait loci (QTLs) governing LTS tolerance for any given growth stage over different genetic backgrounds of mapping populations under different low-temperature stress conditions remains a crucial barrier for adopting marker-assisted selection (MAS). In this review, we discuss the ideal location and phenotyping for agromorphological and physiological parameters as indicators for LTS tolerance and also the traits associated with QTLs that were identified from biparental mapping populations and diverse rice accessions. We highlight the progress made in the fields of genome editing, genetic transformation, transcriptomics, and metabolomics to elucidate the molecular mechanisms of cold tolerance in rice. The stage-specific QTLs and candidate genes for LTS tolerance brought out valuable information toward identifying and improving LTS tolerance in rice varieties. We showed 578 QTLs and 38 functionally characterized genes involved in LTS tolerance. Among these, 29 QTLs were found to be colocalized at different growth stages of rice. The combination of stage-specific QTLs and genes from biparental mapping populations and genome-wide association studies provide potential information for developing LTS-tolerant rice varieties. The identified colocalized stage-specific LTS-tolerance QTLs will be useful for MAS and QTL pyramiding and for accelerating mapping and cloning of the possible candidate genes, revealing the underlying LTS-tolerance mechanisms in rice. | Genetics and Breeding of Low-Temperature Stress Tolerance in Rice | 10.1007/978-3-030-66530-2_8 |
2021-01-01 | The South African Lowveld is a region of land that lies between 150 and 2000 m above sea level. In summer the region is characterized by the maximum mean daily ambient temperature of 32 °C. The purpose of the study was to characterize indoor thermal environments in low-cost residential dwellings during summer seasons as climate is changing. Indoor and ambient air temperature measurements were performed at a 30-min temporal resolution using Thermochron i Buttons in the settlement of Agincourt. 58 free running low-cost residential dwellings were sampled over the summer seasons of 2016 and 2017. Complementary ambient air temperature data were sourced from the South African Weather Service (SAWS). Data were transformed into hourly means for further analysis. It was found that hourly maximum mean indoor temperatures ranged between 27 °C (daytime) and 23 °C (nighttime) for both living rooms and bedrooms in summer 2016 while in 2017, maximum mean indoor temperatures ranged between 29 °C (daytime) and 26 °C (nighttime) in living rooms and bedrooms. Pearson correlations showed a positive association between indoor and ambient temperatures ranging between r = 0.40 (daytime) and r = 0.90 (nighttime). The association is weak to moderate during daytime because occupants apply other ventilation practices that reduce the relationship between indoor and ambient temperatures. The close association between nighttime ambient and indoor temperature can also be attributed to the effect of urban heat island as nighttime ambient temperature remain elevated; thus, influencing indoor temperatures also remain high. These findings highlight the potential threat posed by a rise in temperatures for low-cost residential dwellings occupants due to climate change. Furthermore, the high level of sensitiveness of dwellings to ambient temperature changes also indicates housing envelopes that have poor thermal resistance to withstand the Lowveld region’s harsh extreme heat conditions, especially during summer. The study findings suggest that a potential risk of indoor overheating exists in low-cost dwellings on the South African Lowveld as the frequency and intensity of heat waves rise. There is therefore a need to develop immediate housing adaptation interventions that mitigate against the projected ambient temperature rise for example through thermal insulation retrofits on the existing housing stock and passive housing designs for new housing stock. | Risks of Indoor Overheating in Low-Cost Dwellings on the South African Lowveld | 10.1007/978-3-030-45106-6_123 |
2021-01-01 | PFM has been changing with improvement of plasma confinement Confinement , targeting higher density and temperature for self-burning. Now major criteria for the choice of plasma-facing materials (PFM) are (1) tolerance to high-power load, (2) long lifetime including low erosion and tolerance to neutron damage, and (3) low tritium retention. At present, W seems to be a very good PFM, if its central accumulation could be avoided by suitable impurity transport control. Prompt deposition Prompt deposition of W is very promising because it reduces the net erosion Net erosion and long-range transport. Consequently, deposition at remote area Remote area is suppressed. However, effects of neutron irradiation and Tritium (T) retention require different assessment for PFM selection. Although low T retention is better and has been one of the most important criteria for the selection of PFM of ITER ITER , easy recovery Easy recovery would be more important for T fuel self-sufficiency Fuel self-sufficiency and T safety T safety in a reactor. In this respect, C-wall C-wall seems better, because most of T is retained in deposited layers and near-surface regions of eroded area Eroded area , while bulk retention Bulk retention is dominant for W-wall and difficult to recover. The selection is not easy. Hopefully, ITER ITER could be used for researches for selection of PFM in a reactor. | Selection of Plasma-Facing Materials | 10.1007/978-981-16-0328-0_10 |
2021-01-01 | The use of low-cost adsorbents from agricultural wastes was reviewed for industrial applications. Agricultural Waste is needed for sustainable agricultural practices but could also be considered essential in wastewater treatment operations. Adsorption will be reviewed heavily in this chapter. Chemical and physical characteristics that aid its role as an adsorbent and the suitable industrial applications will be explored. | Agricultural Waste as a Low-Cost Adsorbent | 10.1007/978-3-030-61002-9_4 |
2021-01-01 | The analysis of laser pulse effects on polymers is presented as applied to laser ablation propulsion. Polymers of CHO-chemical composition are considered to use as propellants to increase the efficiency of LAP by burning of polymer vapors and producing such combustion components of this reaction as CO 2 and H 2 O. Theoretical analysis of the ablation effects is considered on the base of polymers burning models. Moreover, high-temperature oxidation of the ablated CHO-materials as well as release of combustion energy in the ablated vapor are considered as basic chemical reactions resulting from laser ablation of polymers. The first reaction is a chemical oxidation of the vapor components by oxygen entering into the polymer’s composition. The second reaction is a delayed burning of the partially oxidized vapor components in the atmospheric oxygen. In the case of the laser ablation propulsion based on the ablation of CHO-polymers, the concept of laser-propulsion efficiency is defined more correctly by the analogy with the efficiency of conventional jet engines, namely, as a ratio of exhaust jet power to the total power of the energy sources originated in a combustion chamber. | Laser Ablation of Solid Materials, Laser Ablation Propulsion | 10.1007/978-3-030-79693-8_3 |
2021-01-01 | The present chapter describes the importance as well as science and technology of microalloyed or high-strength low-alloy steels which are, tonnage-wise, one of the most widely used material worldwide. The introduction part deals with the origin of the microalloying concept, and subsequently, the roles of different microalloying elements in terms of dissolution and precipitation have been discussed at length. The importance of addition of elements such as Ti, Nb, V, etc. for imparting strength has been described in detail. The processing of such steel is a major technical challenge as many metallurgical parameters (e.g., strain rate, recrystallization, extent of mechanical deformation, formation of new grains, precipitation of metallic carbides and carbonitrides, etc.) have to be considered before finalizing a particular rolling schedule in order to obtain the desired microstructure which can meet the required mechanical properties. Finally, two important application-oriented characteristics, namely, weldability and formability of this family of steels, have been discussed briefly. | Microalloyed Steels | 10.1007/978-3-030-53825-5_3 |
2021-01-01 | In friction stir welding (FSW) process, material flow is the most important aspect which affect the mechanical properties and microstructure of the welded joints. The good plasticized material flow reduces the formation of defects in the welded joint. In the present study, a three-dimensional volume of fluid (VOF) model based on ANSYS 14.5 FE software package was developed to predict the effect of traverse speeds (i.e. 90, 132 and 180 mm/min) on material flow behaviour during FSW of low carbon steel. Stain and temperature-dependent material properties were incorporated in developed material flow model. It is observed that the tool traverse speed strongly influenced the mixing of plasticized material in FSW of low carbon steel. The velocity of material flow was reduced as the distance increases away from the rotating axis of the probe or weld zone. The velocity vector of plasticized material was different at different planes throughout the welded joint. The material in plane nearby the top surface exhibited the maximum velocity than the plane close to the bottom surface. Experiment was also carried out using tungsten carbide tool to validate the material flow model. The transient thermal profile obtained from FE analysis and experiment was agreed properly well for peak temperature with a maximum percentage error of 6.72%. | Numerical Study on Material Flow Behaviour in Friction Stir Welding of Low Carbon Steel | 10.1007/978-981-15-7711-6_19 |
2021-01-01 | Abstract In recent years, studies into the processes of bed agglomeration during the combustion of biomass have become increasingly relevant. The agglomeration processes are most largely influenced by the alkaline components of ash, which form low-melting eutectics by reacting with silicates. Therefore, it is very important to determine the critical concentration, primarily, of potassium that forms the most low-melting eutectics in the bed, at which the particles begin to sinter. The experimental studies are aimed at to investigate the effect of the temperature and the concentrations of alkaline elements on the process of particle agglomeration during the combustion of various types of biomass as well as biomass and coal, studying the presence of bed drain, determining the critical concentration of potassium in the bed, and calculating the estimated time before the start of sintering under conditions of an increase of potassium concentration in the bed. The experimental techniques and characteristics of the four studied types of biomass are described. Data on the fraction of agglomerated particles in the bed at different temperatures and concentrations of alkaline elements are given. Upon replacing a part of the sand by iron oxides, agglomeration is observed only at high temperatures (850°C and more). The obtained data are compared with the results of similar experiments carried out under conditions of the fluidized bed; in these experiments, the effects of the fluidization rate, particle size, and excess air on the agglomeration processes are considered. It is noted that the limiting potassium concentration is lowest in the case of a fixed bed. It is shown that real objects should be used when studying the dependence of the behavior of the potassium concentration in the bed on the operation time. The choice of the fraction of bed drain with the addition of a screened material or fresh sand is of practical interest. The calculation techniques and calculated data obtained with use of them on the behavior of the potassium concentration in the bed under various conditions are presented. The fractions of bed drain during combustion of sunflower husks and bark and wood waste are determined. In addition, it is shown that the joint combustion of husks and coal sharply reduces the probability of bed agglomeration. | A Study into the Influence of Different Factors on the Behavior of Alkaline Element Concentrations that Cause Bed Agglomeration | 10.1134/S0040601521010171 |
2021-01-01 | Sensors and sensing systems are paving way for the Internet of things (IoT). Interconnectivity of sensors is aiding the capture of information on a real-time basis, thus aiding the decision support system. Specifically, in agricultural, industrial, food, commercial, military, biological, and many other sectors, sensors are playing an important role. Present-day sensors are built on micro-sized sensing particles and are also cost-effective. One major advantage of a micro-sized sensor is the availability of high surface area and a good surface-to-volume ratio. They also are capable of detecting lower concentration molecules at the PPM/PPB level. Different types of nanomaterials are being studied mainly for reusability and low-temperature sensing. 1D and zero-dimensional nanostructures are mainly used along with different nanomaterials like metal oxides, conducting polymers, ceramics, semiconductors, optical materials, etc. Different types of sensors are being used for different applications like gas sensors, pressure sensors, humidity sensors, environmental sensors for monitoring, biosensors, etc. All these sensors are synthesized by various methods, both wet chemical methods and physical methods. The present chapter deals with all the abovementioned facts with a brief comparison of the performance criteria. | Nanostructure Material-Based Sensors for Environmental Applications | 10.1007/978-3-030-72076-6_22 |
2021-01-01 | Research on the recycling of bulk industrial wastes in the production of granular and block foam materials is reviewed. The possibilities and prospects for obtaining materials with high technical and operational metrics and environmental load reduction are shown discussed. | Use of Bulk Industrial Wastes in the Production of Glass Foam Materials | 10.1007/s10717-021-00312-0 |
2021-01-01 | The innovative combined physical-chemical and biological process system has been elaborated and proposed as an alternative technology for municipal wastewater treatment plants operation. In a series of laboratory bench-scale experiments, typical raw municipal wastewater from the Town of Lee, Massachusetts, USA, was treated directly or elevated to design concentrations (BOD 5 /TSS/NH 3 -N = 250 mg/L/250 mg/L/25 mg/L) before treatment. The current and future National Pollutant Discharge Elimination System (NPDES) effluent limitations were the goals for wastewater treatment in this research. The innovative dissolved air flotation (DAF) technology was applied for primary and secondary clarification. The improved activated single-sludge process was applied for biological treatment (carbonaceous oxidation, nitrification, and denitrification) under simulated cold weather conditions (5 °C). Three complex experiments were performed to prove the system efficiency. It is concluded that the combination of primary DAF, aerobic carbonaceous oxidation, aerobic nitrification, anoxic denitrification, secondary DAF-filtration, and chlorination is an effective innovative system for municipal wastewater treatment. The future NPDES effluent standards can be met. The addition of returned activated sludge (RAS) stabilization tank will increase the efficiency of biological treatment. | Innovative Wastewater Treatment Using Activated Sludge and Flotation Clarifications Under Cold Weather Conditions | 10.1007/978-3-030-54642-7_7 |
2021-01-01 | There is great interest in incorporating methanol fuel across a variety of energy and transportation sectors for many reasons, including increased regional availability, potential to use renewable fuel production pathways, and lower fuel costs compared to petroleum-derived fuels. This chapter describes a method of integrating methanol into a traditional diesel engine architecture, allowing the engine to operate on 100% methanol fuel while maintaining high torque and efficiency. By using increased engine insulation, a high-temperature environment is created which enables any fuel, regardless of cetane number, to auto-ignite with short ignition delay time upon direct injection. This “fuel agnostic” mixing-controlled compression ignition engine can be operated on fuels such as methanol or ethanol, without ignition improver additives. Further benefits arise from marrying a low-carbon fuel like methanol to this high-efficiency architecture—namely that the engine can be operated at a stoichiometric air/fuel ratio, without exceeding soot emission regulation limits nor requiring a particulate filter to do so. Finally, the stoichiometric ratio allows for three-way catalysis after treatment, an order of magnitude lower in cost and more effective than selective catalytic reduction, providing a credible pathway to meeting near-zero NOx standards such as the 0.02 g/hph target. In this way, emissions of soot, NOx, and net CO 2 (if renewable pathways are used to produce methanol) can all be lowered, enabling cleaner air quality and a ready transition to a low-carbon global economy. | Heavy Duty Diesel Engines Operating on 100% Methanol for Lower Cost and Cleaner Emissions | 10.1007/978-981-16-1280-0_8 |
2021-01-01 | Using low voltage Low voltage technology is an effective measure to realize energy saving and consumption reduction of aluminum electrolysis cells. After reducing the cell voltage, the energy balance Energy balance must be adapted to low voltage technology. The authors took 200 kA aluminum reduction cell Aluminum reduction cell as an example. The heat distribution challenge was evaluated from actual measurement results and calculations under the operating conditions of the low-voltage aluminum electrolysis cell. At 0.76 A/cm 2 of anode current density, the total heat loss Heat loss of cell was predicted to be equivalent to 1.223 V, calculated as electric voltage, in which the anode area heat loss was 0.758 V, accounting for 62% of the total heat loss. The cathode area heat loss was 0.465 V, accounting for 38% of the total heat loss. Electrolysis temperature, bath and pad level, the consumption of alumina, anode gross consumption, and anode net consumption on the heat balance were also reported. | The Aluminium Electrolysis Cell Heat Balance Challenge Under Low Voltage | 10.1007/978-3-030-65396-5_59 |
2021-01-01 | The antistatic packaging industries have been facing a challenge when it comes to producing packages to protect sensitive electronic devices from electrostatic charges caused by friction during transport and storage that can cause defects and even destruction of the electronic device. One solution is to use antistatic packaging that is made of a polymeric matrix with the addition of an antistatic agent. The problem is that most of the polymeric matrices used are not biodegradable or from renewable resources, contributing to the increase of waste. An answer can be the production of eco-friendly biodegradable and recyclable antistatic packages. The production of green composites by using biodegradable and recyclable polymeric matrix and antistatic agents of a renewable resource is our object of study. Green low-density polyethylene (green LDPE), biodegradable matrices, as polycaprolactone (PCL), poly(lactic acid) (PLA), and poly(hydroxybutyrate- co -hydroxyvalerate) (PHBV) from renewable resources can be highlighted. A promising conductor-sustainable antistatic agent is the carbon material named as glassy carbon (GC), which has origin in renewable resources and presents good electrical properties and low density. Green composites of eco-friendly polymeric matrices and glassy carbon are showing good antistatic properties for the production of packaging. Thus, this chapter elucidates plenty of ways to produce antistatic packaging and disclose about the innovative way to produce eco-friendly antistatic packaging that presents the same properties as the fossil-based ones. | Green Composites for Application in Antistatic Packaging | 10.1007/978-981-15-9643-8_17 |
2021-01-01 | The Principles of Low Carbon Cement cement industry Cement industry constitutes a severe threat to ecology, including through its negative impact Negative impact on the climate Climate , due to the high level of carbon dioxide CO 2 emissions (CO 2 ) emissions Emissions associated with it. Given that this is the case, the modern world World modern is looking for alternatives Alternatives in order to preserve the environment Environment for future generations Generations . The eventual goal, therefore, is for industry to stop emitting carbon Carbon emitting into the air Air . Many effective steps Steps effective can be taken by industry Industries leaders Industry leaders to achieve lower carbon emission targets Carbon emission targets, lower to improve local ecological systems Systems local ecological . This paper discusses the ways in which CO 2 CO 2 is measured and alternatives to the standard methods Methods standard through which hydraulic cement Hydraulic cement is produced in order to reduce Carbon dioxide CO 2 emissions. The benefits of using alternative Alternatives methods Methods alternative , specifically relying on kilns Kilns and/or synthetic fuels Fuels synthetic , are identified and discussed. An assessment of the conditions Conditions needed for the industrial production Production industrial of new cementitious systems Cementitious systems new in which clinker-calcined limestone Limestone clinker-calcined and low-carbon clay Clays low-carbon are used is also presented. Additionally, an account of the clinkerization process Processes clinkerization of low-carbon Cement low-carbon cement (LCC) is provided. The new materials are shown to meet global standards Standards global in applications Applications such as the production Production of hollow concrete blocks Concrete blocks hollow and precast Precast concrete. In a comparison Comparison between Portland cement Portland cement and the new materials, no major differences were found in either the mechanical or rheological features Features rheological . An environmental ternary cement Assessments environmental ternary cement assessment Assessments is also reported that includes comparisons with other industrially blended cements Blended cements . LCCs LCCs (low-carbon cement) are shown as having the ability to reduce carbon emissions from cement production Cement production by more than 30%. | Principles of Low-Carbon Cement | 10.1007/978-3-030-69602-3_3 |
2021-01-01 | Materials having ions in unusual oxidation states have been of interest for long time due to their relevance in understanding the oxidation–reduction process of various physicochemical phenomena, fundamental ionization process of elements as well as their challenging chemistry to prepare them. The ions in unusual oxidation states are usually unstable, and in turn they transform to stable state under ambient conditions or by feeble alteration of thermodynamic parameters or chemical environments. Since attaining such oxidation states is energetically unfavourable, they are generally achieved by either extreme or non-equilibrium thermodynamic conditions or diagonally opposite mild reactions where alternate paths are adopted. The varieties of unusual oxidation states can be conveniently obtained in solutions, but they are extremely reactive and short-lived, and are often encountered as intermediates in various chemical reactions. Cations with such oxidation states can also be stabilized by a variety of organic ligands. However, this chapter is mainly focussed on solid materials where the ions are stabilized primarily by inorganic counter ions and have significantly higher stability for further studies. In this chapter, a brief overview on preparation of materials having unusual oxidation state is presented. The chapter initially explains about the unusual oxidation state and their interest, and then the modes of their stabilization. There are several case studies explaining the process of stabilization of lower and higher valent states, and the role of judicious chemical and thermodynamic conditions, and crystal structure to stabilize them are presented. | Synthesis of Materials with Unusual Oxidation State | 10.1007/978-981-16-1892-5_5 |
2021-01-01 | Aluminum titanate Al 2 TiO 5 materials were successfully processed from different fine commercial powders and characterized. Particularly, two calcined aluminas were compared through a multitechnique approach including differential thermal analysis and dilatometry together with structural, microestructural, and mechanical characterization. This allowed the description of all the thermochemical processes during thermal treatment. Developed phases were established. Relatively dense ceramics were obtained, and complex microstructures were described with interlocked grains and an interconnected microcrack matrix that do not jeopardize the material integrity. Multistep sintering and reaction sintering processes were observed in both samples. The first stage consists of the sintering of the starting powders (alumina and titania). A second sintering stage of the starting powders was observed for both samples as well. Once advanced, the second one is overlapped with Al 2 TiO 5 formation that starts at 1380 °C and finishes at 1440 °C. They affect crack development and, in consequence, the thermal behavior. The lower alumina particle size enhances the sintering and reaction advance processes. In the technological temperature range (room temperature—1000 °C), low or even negative thermal expansion behaviors were observed in the developed materials. This, together with the mechanical behavior, encourages structural applications with high thermomechanical solicitations of Al 2 TiO 5 based materials. | A dynamic analysis of the aluminum titanate (Al2TiO5) reaction-sintering from alumina and titania, properties and effect of alumina particle size | 10.1007/s10973-020-09284-9 |
2021-01-01 | The use of low transformation temperature (LTT) alloys seems to be a promising way for reducing the residual stress level of fusion welded components. Wire and arc additive manufacturing (WAAM) is a high performance additive manufacturing process for generating large metallic components, which is based on common arc welding processes. The following article describes the investigations regarding generating LTT alloys in WAAM through in-situ alloying. Therefor a multi wire gas metal arc process in spray transfer mode is being used to generate the target LTT alloy. By using two high alloyed cold wires, it was possible to reach a chemical composition for LTT alloys, proposed by Steven and Haynes. The process showed stable behavior and it was possible to build up test specimen in form of wall shaped structures of 15 mm height. By establishing in-situ alloying for the additive manufacturing of LTTs a new field of investigations regarding the structural behavior of LTT-injected components is being opened. | In-Situ Alloying in Gas Metal Arc Welding for Wire and Arc Additive Manufacturing | 10.1007/978-3-030-70332-5_15 |
2021-01-01 | In a low-temperature environment, the performance of lithium-ion batteries is limited greatly due to the slower chemical reaction rate inside the battery and the hindered migration of lithium-ions. Low-temperature charging and discharging tests were carried out on the lithium-titanate battery by using the test device and data acquisition system. During the tests, some parameters were monitored such as the internal resistance, voltage, and temperature, and the low-temperature performance of the lithium-titanate battery was analyzed. The results show that the internal resistance and the charging voltage continue to increase, while the discharging voltage and capacity continue to decrease with the environmental temperature decrease. | Data Collection and Performance Analysis of Lithium-Titanate Battery Charging and Discharging at Low Temperature | 10.1007/978-981-15-8411-4_196 |
2021-01-01 | Based on the investigation and study of the topography and composition of the buildups, combined with production process of low-temperature grain-oriented silicon steel Low-temperature grain-oriented silicon steel , the mechanism and major causes of forming buildups of carbon sleeve Carbon sleeve were discussed from the factors such as the quality of carbon sleeve Carbon sleeve , antioxidants, furnace atmosphere, dew point, running speed of carbon sleeve, and so forth. Meanwhile, some countermeasures to reduce the formation of the buildups were proposed. | Cause Analysis on Buildup Formation of Carbon Sleeve in Continuous Annealing Furnace for Low-Temperature Grain-Oriented Silicon Steel Production | 10.1007/978-3-030-65493-1_24 |
2021-01-01 | Using AC-20 asphalt mixture (Nominal maximum size 19 mm), the semi-circular bending test of recycled asphalt mixture with different amounts of waste frying oils rejuvenators, were conducted and compared with the virgin asphalt mixture. The test results show that the fracture energy of recycled asphalt mixture increased significantly when a waste frying oil rejuvenator was added. When the RAP (reclaimed asphalt pavement) contents were between 30% and 40%, and the rejuvenator contents were between 10.5% and 12.5%, the fracture energy of recycled asphalt mixture can be restored to 62%–72% of that of the virgin asphalt mixture. Therefore, it demonstrated that the waste frying oil rejuvenator was able to effectively improve the low-temperature crack resistance of the recycled asphalt mixtures. | Low Temperature Crack Resistance of Recycled Asphalt Mixture with Waste Frying Oil Based on Semi-circular Bending Test | 10.1007/978-3-030-79857-4_5 |
2021-01-01 | This paper presents an experimental procedure for the characterization of the granitic rocks on a Mars-like environment. To gain a better understanding of the drilling conditions on Mars, the dynamic tensile behavior of the two granitic rocks was studied using the Brazilian disc test and a Split Hopkinson Pressure Bar. The room temperature tests were performed on the specimens, which had gone through thermal cycling between room temperature and − 70 °C for 0, 10, 15, and 20 cycles. In addition, the high strain rate Brazilian disc tests were carried out on the samples without the thermal cyclic loading at test temperatures of − 30 °C, − 50 °C, and − 70 °C. Microscopy results show that the rocks with different microstructures respond differently to cyclic thermal loading. However, decreasing the test temperature leads to an increasing in the tensile strength of both studied rocks, and the softening of the rocks is observed for both rocks as the temperature reaches − 70 °C. This paper presents a quantitative assessment of the effects of the thermal cyclic loading and temperature on the mechanical behavior of studied rocks in the Mars-like environment. The results of this work will bring new insight into the mechanical response of rock material in extreme environments. | Effects of Test Temperature and Low Temperature Thermal Cycling on the Dynamic Tensile Strength of Granitic Rocks | 10.1007/s00603-020-02253-6 |
2021-01-01 | Energy is required to realize human potential. A vast majority of human race lacks access to adequate energy resources especially electricity. Electricity usage and gross development product (GDP) are intimately related; higher electricity usage leads to higher GDP. Electricity generation and distribution based on large-scale power plants, if applied to developing economies, will be prohibitively expensive and environmentally unsustainable. A shift from macro to micro grids based on distributed energy resources is needed. Renewable electricity generation is an integral part of this shift with crystalline silicon (Si) solar cell as its engine. Industrial development of Si solar cell is largely attributed to the advanced infrastructure development in semiconductor and integrated circuit manufacturing. Analysis of solar cell performance identifies quality of the starting Si wafer as the most important factor impacting its efficiency. Inherent flexibility in solar cell fabrication allows wide latitude: from screen printing to vacuum processing based on toxic gases. Industrial manufacturing of solar cell is approaching limits in terms of production cost and wafer parameters. Trends in the future will likely follow two pathways: inexpensive, high temperature processing based on environmentally friendly processes and expensive low temperature processes based on vacuum equipment and toxic gases. | Sustainable Electricity Generation | 10.1007/978-3-030-73379-7_1 |
2021-01-01 | Rubber bearings for bridges are important attachments connecting superstructure and substructure of bridges, and grasp of durability performance is very important. Deterioration (fatigue) due to external forces is a non-negligible task in bridge member that require long-term durability, but there is no research report on deterioration (fatigue) of rubber bearings in low temperature environments. So we conducted a field survey on damage and conducted a fatigue test at low temperature. In the field survey, it was found that the influence of low temperature on resistance to fatigue deterioration and mechanical properties etc of rubber bearings cannot be denied. Moreover, from the results of the compression fatigue test in the low temperature condition, it was found that the low temperature environment affects the vertical support characteristics of the rubber bearing. | Study on Compression Fatigue of Rubber Bearings Used in Low Temperature Environment | 10.1007/978-981-15-8079-6_92 |
2021-01-01 | Li 0.33 La 0.55 TiO 3 (LLTO) is a solid Li-ion conductor with high bulk ionic conductivity. However, a high processing temperature, typically around 1300 °C, is generally required for obtaining its crystallization. In this work, LLTO was successfully synthesized at temperatures as low as 900 °C by tape casting method. Thermogravimetric analysis was carried out on the precursors for clarifying the weight loss and related phase transformations, and powder X-ray diffraction analysis was performed on the final products for verifying the crystallinity and phase purity in the low-temperature-processed LLTO electrolytes. The morphology of the synthesized LLTO powders was observed by scanning electron microscopy for understanding the microstructural evolution with increase of the sintering temperature. The ionic conductivity and activation energy of LLTO solid electrolytes were measured. A typical ionic conducting behavior with a moderate total conductivity of 4.3 × 10 −6 S/cm and a quite low activation energy of 0.29 eV was obtained in the 900 °C-derived LLTO sample. When the processing temperature was raised to 1350 °C, the total ionic conductivity was further enhanced, reaching 6.13 × 10 −5 S/cm. When the LLTO pellets were subject to cold isostatic pressing, the low-temperature (900 °C)-processed LLTO sample also presented a high conductivity of 2.1 × 10 −5 S/cm. This work sheds light on the low-temperature synthesis of LLTO-based solid electrolytes for solid-state lithium battery applications. | One-step low-temperature synthesis of Li0.33La0.55TiO3 solid electrolytes by tape casting method | 10.1007/s11581-020-03823-y |
2021-01-01 | High usage of dyes by textile, paper and pulp, tannery and paint, plastic, cosmetics, and food industries generates effluents containing hazardous dyes and auxiliaries. In order to eliminate this problem, it is desirable to look for effective, sustainable, and efficient methods for wastewater treatment containing dyes. Overview regarding disposal of dyes by adsorption using such material as carbonaceous sorbents (commercial activated carbons, fullerenes, nanotubes, activated carbons prepared from wastes), naturally occurred substances (clays, zeolites, siliceous materials), nonconventional low-cost adsorbents (agriculture wastes, e.g., leaves, fruits, straw, rice husks, chaff, vegetable fibers, sunflowers stalks, or wastes from industry such as red mud, metal hydroxide sludge, fly ash, as well as biosorbents such as living or dead biomass, e.g., algae, yeast, bacteria, fungi), composites and nanocomposites, nanomaterials, as well as ion-exchange resins. The physicochemical properties of the above mentioned sorbents and their sorption capacities were compared toward different types of dyes based on a literature review. | Characteristics and Adsorptive Treatment of Wastewaters Containing Dyes | 10.1007/978-3-030-47400-3_11 |
2021-01-01 | The development of steels with increasing strength levels, while retaining a sufficient ductility and toughness, has been the major focus area of research in recent times. These property combinations can be achieved by (i) tailoring and enriching the composition, e.g. TWIP and austenitic stainless steels, (ii) optimization of processing parameters and (iii) employment of novel processing route, etc. The higher alloying additions to steel lead to increased cost and pose difficulty in casting, rolling, welding, fabrication, etc. Therefore, it is of significant importance to achieve higher strength levels in low alloy steel compositions with the help of novel processing routes. One such approach is quenching and partitioning (Q&P) process, which leads to the stabilization of retained austenite in a martensitic matrix. Some of the recent studies have also shown the presence of bainite and carbides, in addition to the retained austenite and martensite, leading to a multiphase microstructure at room temperature. The Q&P process involves austenitization, hot rolling, quenching in the M s –M f range, followed by isothermal holding and cooling to room temperature. The isothermal holding helps in the partitioning of supersaturated carbon in the martensite to the remaining austenite, which leads to the stabilization of austenite and its retention at room temperature. As an alternative, the extremely slow cooling of a hot-rolled coil, after the quenching at the run-out table, can also be used for this purpose, eliminating the need for an extra arrangement for isothermal holding. In view of the above, the present paper describes the pros and cons of the application of this energy-efficient Q&P approach to low alloy steels. | The Pros and Cons of an Energy-Efficient Q&P Approach to Develop Advanced Steels | 10.1007/978-981-16-0182-8_2 |
2021-01-01 | In this work, both dynamic water vapor sorption (DVS) and low temperature calorimetry (LTC) methods were adopted to study the pore size distribution of cement pastes prepared by two types of cements CEM I and CEM III. A model porous material, MCM-41, was also included in order to investigate important aspects of the measurement and the data evaluation approaches. As indirect methods for pore structure characterization, important assumptions involved in the data analysis of both methods were highlighted and discussed. In addition, a special attention was paid to the comparison of the results obtained from the two methods. A careful examination of the bases for the two methods for pore structure characterization revealed that a number of matters could affect the obtained results, including sample preparation, possible influencing factors on the measured results, unsolved factors for data analysis, etc. Consequently, the results obtained from one method might differ significantly from the other. Nevertheless, a certain degree of agreement was still found for the pore size distributions determined by the DVS and the LTC methods, despite of the uncertainties involved in each method. Meanwhile, it was concluded that probably none of the two studied methods could deliver the “true” (actual) pore size distribution information at this stage. To further improve the accuracy of the results obtained from the methods, it was highlighted that emphases should be laid on clarifying relevant assumptions made in both measurement and data analysis. | Pore Size Distribution of Cement Based Materials Determined by Dynamic Water Vapor Sorption and Low Temperature Calorimetry | 10.1007/978-3-030-76551-4_32 |
2021-01-01 | Lead-free solder, tin, tin/silver (SnAg), and tin/silver/copper (SnAgCu) alloy nanoparticles with various sizes were synthesized via a low-temperature chemical reduction method, and their thermal properties were studied by differential scanning calorimetry. The particle size dependency of the melting temperature and the latent heat of fusion were observed. The wetting test for the as-prepared SnAg and SnAgCu alloy nanoparticle pastes on a Cu surface showed the typical Cu6Sn5 intermetallic compound (IMC) formation. These low melting point SnAg or SnAgCu alloy nanoparticles could be used for low reflow temperature lead-free interconnect applications. | Nanolead-Free Solder Pastes for Low Processing Temperature Interconnect Applications in Microelectronic Packaging | 10.1007/978-3-030-49991-4_5 |
2021-01-01 | Sometimes, a combination of deep knowledge, serendipity and perseverance can lead to developments that set aside decades of attempts. The story of the world’s first bulk nanostructured metal is an example of this. The phase change that led to the material was, back in the 1970s, so controversial that textbooks of the time would not dare to venture opinions. The subject has calmed over a period of about half a century, so much so that the theory can be used to create materials that fire the imagination. The story is illustrated here. | First Bulk Nanostructured Metal | 10.1007/978-3-030-57612-7_8 |
2021-01-01 | Using of condensing low-temperature heating surfaces in exhaust gas boilers allows to increase the economic efficiency of boilers and thermal power plants. Analysis of literary sources showed, that there were no quantitative data of the low-temperature corrosion intensity of exhaust gas boiler low-temperature heating surfaces while water-fuel emulsion combustion. Experimental investigations of corrosion processes of low-temperature heating surfaces in exhaust gas boilers with excess air factor in the range of 1.5…3.0 were carried out. The empirical correlations for dependence of specific metal mass loss on water content of water-fuel emulsion, sulfur content in output fuel and excess air factor α at wall temperatures below the dew point temperature of sulfuric acid vapor, which characterize the low-temperature corrosion intensity of condensation surfaces at different operating modes of exhaust gas boilers were received. For estimation of the influence of the quality of combustible fuel and its combustion regimes on the corrosion intensity, a computer simulation was conducted by using the statistical program package Statgraphics Centurion XV. These correlations show that the smallest values of corrosion intensity are observed at large values of water content in water-fuel emulsion of about 30%. The minimum values of exhaust gas temperature at the exit from exhaust gas boiler and of wall temperature are determined, at which the permissible speed of low-temperature corrosion at a level of 0.25 mm/year is ensured. | Investigation of Condensing Heating Surfaces with Reduced Corrosion of Boilers with Water-Fuel Emulsion Combustion | 10.1007/978-3-030-66717-7_25 |
2021-01-01 | Cement production is an exothermic process and contributes approximately 8% of world’s total anthropogenic CO 2 emission. The growing demand for cement and increasing concerns over environmental sustainability has prompted the cement community to search for alternative, eco-cementitious binders. In the last few decades, several eco-cementitious binders have been proposed with lower embodied energy and reduced carbon footprint than that of ordinary Portland cement (OPC). This chapter focuses about six promising alternative cement binders which have the potential to be adopted in varieties of building and infrastructure projects. The chapter briefs about the involved cement chemistry, characteristics, raw material used, their availability, and current application of (a) calcium sulfoaluminate, (b) alkali activated, (c) magnesium oxide, and (d) limestone calcined clay cement. Besides that, chapter also presents the critical appraisal on CO 2 reduction potential of the studied alternative cements, current challenges, and future direction of research. The scientific value of this chapter was to serve the substantial base of knowledge to the students, researchers, and practicing professionals for the development and conventional application of eco-cementitious binders. | Low Energy/Low Carbon Eco-Cementitious Binders as an Alternative to Ordinary Portland Cement | 10.1007/978-3-030-58675-1_143-1 |
2021-01-01 | Among various types of building insulation materials developed to solve the problem of energy crisis, foam concrete is particularly interesting for its special attributes such as excellent low density, high flowability and excellent thermal insulation. The focus of this paper is to classify the literature on thermal behaviour of foamed concrete which includes the major factors affecting thermal properties and available methods of measuring it along with its pros and cons. Based on the review conducted it is observed that among the various factors studied, the microstructural parameters such as porosity, pore size and pore shape influences the thermal conductivity of foamed concrete to a great extent. Further, the literature evidence indicates that the constituent materials affects the microstructure of foamed concrete, which eventually affects its thermal behaviour. Also, studies indicate that use of foamed concrete for different structural and non-structural building applications is a viable method for reducing the heat transfer owning to its lower thermal conductivity value. | Thermal Properties of Foamed Concrete: A Review | 10.1007/978-3-030-51485-3_9 |
2021-01-01 | Mathematical models of serrated plastic deformation in metals at ultra-low temperatures are developed. In the framework of the dislocation model, the instability of the plastic flow is shown to be caused by the relay mechanism of overcoming barriers (sub-boundaries, grain boundaries, etc.) by dislocation clusters. Regularities of localization of plastic deformation in alloys are described on the base of the model of interaction of dislocations with point defects. Within the scope of the thermodynamic model, it has been analytically and numerically established that in the range of helium temperatures, a change in the deforming stress, temperature, and plastic strain rate acquires an irregular stochastic nature. The obtained results are in good agreement with experimental data and can be used to construct the theory of plastic deformation of structural metals and alloys in the region of extremely low temperatures. | Instability of Plastic Deformation in Metals at Low Temperatures | 10.1007/978-3-030-54928-2_31 |
2021-01-01 | Dual-curing adhesives offer a high precision, and, due to their manifold curing mechanisms a unique process speed and flexibility in production processes. To reach short cycle times, fast UV fixation is utilized allowing for an immediate continuation of the production process. This initial fixation step is followed by a second final curing step. The example of the production process of a camera for e.g. autonomous driving shows how to finally obtain the adhesive’s properties in the second process step. We present a new hybrid system, a lightfixable 2-component adhesives that allow final curing at room temperature. It therefore saves time, energy and space in the production plant. | Dual-curing adhesives for fast cycle times and high-precision alignment of components | 10.1007/978-3-658-29701-5_6 |
2021-01-01 | Water borne polyurethanes have gained significant attention due to high-performance, excellent elasticity, no toxicity, abrasion resistance, adhesion functionality, flexibility, environmental friendliness, and broad substrate suitability. The physiochemical properties of water borne polyurethanes include low temperature, one component application, low viscosity, low solubility, and excellent coating performance. Therefore, this chapter intends to provide a detailed information sustainable production and applications of water borne polyurethanes. Different techniques such as thermal gravimetric analysis, Fourier transform infrared spectroscopy, mechanical measurements, and dynamic thermomechanical analysis used for the characterization of water borne polyurethanes were also highlighted. Moreover, detailed information on the application of water borne polyurethane plus polyurethane-urea dispersions for the production of novel eco-friendly nanomaterials were also highlighted. | Novel Research Areas of Applications for Water Borne Polyurethanes | 10.1007/978-3-030-72869-4_7 |
2021-01-01 | The chapter is dedicated to analysis of the semiconductor microwave devices, purposed directly for construction of the electronic modules of the modern radar sets and systems of communications. Here in detail is considered the element base of the combined modules of AFAR (attenuators, phase shifters, switches, fore amplifiers, low noise amplifiers and power amplifiers, as well as a wide spectrum of the noise suppression devices for AFAR. The nomenclature and the basic technical parameters are indicated of the major Russian manufacturers (JSC “Microwave Systems”, CJSC “RPA “Planet-Argall”, RPA “Pulsar” and others), under consideration are also the basic “western” integrated circuits for the combined modules of the radar sets, based on gallium nitride, in particular of the manufacturers “Mini-circuits”, Hittite Microwave and others. Here are also considered the important specific features for selection of the element base for the systems of the secondary power supply of AFAR. | Semiconductor SHF Devices for Radar Sets | 10.1007/978-3-030-58699-7_8 |
2021-01-01 | Abstract The influence of three multipass cross rolling patterns on the microstructure, mechanical properties and fracture toughness of ferrite-pearlitic pipe steel 09G2S is investigated using mechanical testing, optical metallography, transmission and scanning electron microscopy. Upon all cross-rolling patterns, a change in the parameters of the initial workpiece grain structure is observed with the formation of layered grain size distribution. Near the workpiece surface, the size of globular grains is 1–4 μm, the length of elongated grains in the central part of the workpiece varies from units to tens of μm, and the width varies from 1 to 8 μm. Mechanical tests for uniaxial tension and impact strength are carried out on specimens machined from the central part of the bar. It is established that cross rolling leads to an increase in the yield point and ultimate strength of steel after all investigated patterns with a slight decrease in the overall plasticity. The greatest increase in impact toughness at T = –70°C is observed after controlled cross rolling in the temperature range 850–500°C. Using electron microscopic studies, it is shown that the mechanical behavior of the cross-rolled specimens is associated with structural transformations that occur in steel during rolling and cooling. The main strengthening factor is the refinement of ferrite grains and the formation of a subgrain structure as cross rolled. The increase in impact toughness is associated with a more uniform finely dispersed structure of rolled products, which does not contain cementite and bainite plates. Temperature dependent fracture processes of the initial cross-rolled steel specimens are analyzed based on recorded shock loading diagrams and structures in the rupture areas of Charpy specimens. | Influence of Cross Rolling Patterns on the Mechanical Properties and Fracture Toughness of Pipe Steel | 10.3103/S0967091221010113 |
2021-01-01 | In Erosion continuous Resistance to ammonia annealing Continuous annealing furnace for low-temperature grain-oriented silicon steel Low temperature grain-oriented silicon steel production, carbon sleeve Carbon sleeve is used as one kind of the best hearth rolls to support and convey steel strip. However, the surface of carbon sleeve in nitriding Nitriding zone is seriously corroded after a period of time, the surface roughness of carbon sleeve increases, the edge wears and even buildups appear, which seriously affects the surface quality of products. Based on the working conditions of carbon sleeve, the causes and mechanism of corrosion on carbon sleeve by ammonia, and effects of antioxidants on surface quality of low-temperature grain-oriented silicon steel Low temperature grain-oriented silicon steel are discussed. In terms of the resistance to ammonia Resistance to ammonia , phosphate is not a good antioxidant for carbon sleeve Carbon sleeve in continuous annealing Continuous annealing furnace for low temperature grain-oriented silicon steel Low temperature grain-oriented silicon steel production. | Effect of Antioxidant on Resistance to Ammonia Erosion of Carbon Sleeve in Continuous Annealing Furnace for Low-Temperature Grain-Oriented Silicon Steel Production | 10.1007/978-3-030-65241-8_28 |
2021-01-01 | This article presents the results of the charge composition development for heat-resistant ceramics production based on low-plasticity clay with the addition of 10 wt. % of cerium oxide and 5 wt. % of boric acid as functional additives. It has been stated that self-glazing effects on the surface and ceramic particles glazing in the products depth are observed during joint introduction of these additives. These effects occur as boric acid, being a strong flux, forms a vitreous phase and reduces liquid-phase sintering temperature of ceramics. This vitreous phase based on borosilicates includes cerium oxide, as well as silicon, aluminum, calcium and magnesium oxides, which are characterized by high melting points, chemical resistance and heat resistance. This vitreous phase is represented in the structure of the material in the form of the layers between the ceramic particles and forms a single frame possessing low thermal coefficient of linear expansion, which contributes to the compaction, open porosity reduction, material strength characteristics and heat resistance increase. The advantages of cerium oxide are the reduction of the difference between thermal coefficients of linear expansion between the amorphous and crystalline phases in the material, as well as the ability of this substance to serve as a catalyst for hydrocarbons and soot oxidation when heated. The obtained results allow using the obtained ceramics for lining thermal units and flue channels operated at high temperatures and in aggressive environments, alongside the production of self-cleaning walls without interrupting thermal units operation. | Charge Composition Development for Heat-Resistant Ceramics | 10.1007/978-3-030-57453-6_43 |
2021-01-01 | At low lattice temperatures $$\left( {T_{{\text{L}}} \le 20\,K} \right)$$ T L ≤ 20 K , an apparently low electric field may effectively serve as high enough to significantly perturb an electron ensemble in a semiconductor from the state of thermodynamic equilibrium with the lattice atoms. The energy loss rate by an electron of the ensemble through impact ionization and excitation of neutral impurities may turn out to be comparable with the loss rate through interactions with the prevalent phonons and this takes part in controlling the non-Ohmic characteristics of the material. The present analysis deals with the calculation of the net energy loss rate of an electron and the subsequent effective electron temperature characteristics. The results obtained for InSb are compared with other theoretical and available experimental data. The agreement with the experiments is quite satisfactory. Moreover, the effects of impact ionization and neutral impurities at low temperatures are indeed not always negligible. | Effect of Energy Loss Due to
$$1s \to 2p$$
1
s
→
2
p
Excitation and Ionization of Neutral Impurities on the Non-Ohmic Characteristics of a Compound Semiconductor at Low Lattice Temperature | 10.1007/978-981-15-8366-7_57 |
2021-01-01 | Phase-change materials are important for optical and electronic computing memory. Ge–Sb–Te (GST) is one of the important phase-change materials and has been studied extensively for fast, reversible, and non-volatile electronic phase-change memory. GST exhibits structural transformations from amorphous to metastable fcc at ~150 ℃ and fcc to hcp at ~300 ℃. The investigation of the structural, microstructural, and microchemical changes with high-temporal resolution during heating is crucial to gain insights on the changes that materials undergo during phase transformations. The as-deposited GST film has amorphous island morphology which transform to the metastable fcc phase at ~130 ℃. The second-phase transformation, from fcc to hexagonal, is observed at ~170 ℃. While the as-deposited amorphous islands show a homogeneous distribution of Ge, Sb and Te, these islands boundaries become Ge-rich after heating. Morphological and structural evolutions were captured during heating inside an aberration corrected environmental TEM equipped with a high-speed camera under a low-dose conditions to minimize beam-induced changes in the samples. Microchemical studies were carried out employing ChemiSTEM technique in probe-corrected mode with a monochromated beam. | TEM Studies of Segregation in a Ge–Sb–Te Alloy During Heating | 10.1007/978-981-16-2982-2_11 |
2021-01-01 | The high cost of carbon fibre continues to limit its use in industries like automotive, construction and energy. Since the cost is closely linked to the precursor, considerable research has focussed on the use of low-cost alternatives. A promising candidate is a composite fibre consisting of blended cellulose and lignin, which has the added benefit of being derived from sustainable resources. The benefits of blending cellulose and lignin reduce some of the negative aspects of converting single component cellulose and lignin fibres to carbon fibre, although the production from such a blend, remains largely underdeveloped. In this study, the effects of stabilisation temperature and the stabilisation process of the blended fibres are explored. Moreover, the viscoelastic properties of the cellulose-lignin fibre are investigated by DMA for the first time. Finally, the cause of fusion in the stabilisation is adressed and solved by applying a spin finish. | Understanding the influence of key parameters on the stabilisation of cellulose-lignin composite fibres | 10.1007/s10570-020-03583-y |
2021-01-01 | The influence on the rheological properties of bitumen of the powder rubber modifier (PRM), based on active powder of discretely devulcanized rubber (APDDR) has been investigated. APDDR obtained by the method of High-Temperature Shear Grinding from the Crumb Rubber of waste tire. A specific feature of APDDR is its rapid decay into micro- and nano-fragments upon contact with hot bitumen, which allows using PRM during mixing asphalt concrete without changing the temperature and time conditions for preparing the mixture. The change in the structure of the binder upon addition of PRM to bitumen is shown by AFM-spectroscopy and by the example of the change in the complex viscosity: at high temperatures it is higher, but starting from a certain temperature, the position of which depends on the thermo-history of the sample, the complex viscosity decreases in comparison with the bitumen. The phenomenon of dynamic glass transition (DGT) at low temperatures observed in bitumen in the frequency range corresponding to vehicles speed is investigated. It is shown that DGT is absent in modified bitumen at the optimum concentration of PRM. The improvement in the fatigue properties of bitumen as a result of modification of the PRM is confirmed both by a decrease in the value of the loss modulus and by the introduced parameter - the fracture temperature during cyclic tests. This temperature corresponds to the sharp cracking of the sample, which occurs during cyclic tests with an increase in strain from 0.1 to 5%, when the loss modulus reaches 25 MPa. | Rheological Properties of Bitumen with Powder Rubber Modifier Obtained by High-Temperature Shear Grinding | 10.1007/978-3-030-72404-7_46 |
2021-01-01 | 3D lithography by means of two- or multiphoton absorption (TPA/MPA) as a special case for direct laser writing has gained considerable attention, particularly in the last two decades. It offers additive, subtractive, and special glass processes. Especially in academics, the possibility to create 3D objects has resulted in many different studies for applications from photonics and microoptics to life science. A special structuring mode in 3D lithography is high-precision 3D printing which is intensely researched all over the world. The combination of high-performance materials with sophisticated fabrication strategies results in a significant reduction of the process time. This leads to a pronounced acceptance of high-precision 3D printing beyond the field of pure research and nowadays into production. This chapter describes the principles of high-precision 3D printing, with the wide range of materials that can be processed being introduced. It is shown how the subwavelength resolution of the fabrication process enables the manufacturing of not only refractive and diffractive optics but also metaoptics. Individual elements from the sub-μm range to the millimeter range are feasible, and the versatile manufacturing strategies enabled by high-precision 3D printing are discussed. Possibilities to significantly scale up the production are highlighted, among them contouring, beam splitting, and others. Examples are given for the direct use of printed optics in applications, but also for using the printed parts as master for replication. | Industrial-Scale Fabrication of Optical Components Using High-Precision 3D Printing: Aspects-Applications-Perspectives | 10.1007/978-3-030-58960-8_5 |
2021-01-01 | The present chapter investigates the moment-independent sensitivity analysis for hybrid sandwich structures (having cylindrical shell geometry) subjected to low-velocity impact. These hybrid structures are extensively used in lightweight applications where thermal exposure/resistance is of prime importance. Here, the FG facesheet is placed at the upper layer of core whereas laminated composite facesheet is kept at lower layer so that the structure can sustain high-temperature exposure at reduced weight because of laminated composite facesheet at the inner layer of the core. The probabilistic study is performed for the transient impact response of the structure which in turn utilized to assess the sensitiveness of the parameters. The computational efficiency is achieved by implementing polynomial chaos expansion (PCE) metamodel in conjunction with Monte Carlo simulation (MCS). The results illustrate the parameters which significantly affect the transient impact response of the structure. | Dynamic Sensitivity Analysis of Random Impact Behaviour of Hybrid Cylindrical Shells | 10.1007/978-981-33-4550-8_11 |
2021-01-01 | In this work, we present an extremely low-temperature (600 °C) liquid-phase synthesis method using KOH as flux to grow YBCO powder and epitaxial films. Oxides utilize solution medium KOH in which target materials are generated by cation’s physical and chemical transformations. Y123 and Y124 films could be synthesized by controlling configuration which is related to oxygen diffusion. Later, the process and mechanism of YBCO growth will be elucidated by DSC. In the presence of KOH, the decarboxylation of BaCO 3 is kinetically favored with the formation of Ba (OH) 2 at the first step, the same as Y 2 O 3 and CuO. Above 350 °C, the formation of Y 2 Cu 2 O 5 will take precedence over Ba 2 Cu 3 O 5 due to the weak solubility of Y 3+ and Cu 2+ in molten KOH. With temperature increasing, liquid Ba(OH) 2 begins to dehydrate, and Ba 2+ subsequently reacts with Y 3+ and Cu 2+ to precipitate YBCO in the last step. Molten KOH provides a liquid chemical environment, which allows the synthesis of YBCO at low temperature. This low-temperature method is applicable to epitaxial superconductor and superconducting joint. | Elucidation of YBCO Growth Mechanism in KOH Flux Method | 10.1007/s10948-020-05675-z |
2021-01-01 | In this study, radon ( 222 Rn) measurements were taken at compacted uranium tailings with cover materials by a self-developed coupling testing system under different low-frequency vibration loads and gas seepage rates. The maximum measured value appears at 0.723 Bq m −2 s −1 , which is close to the upper limit value of national standard of China (0.74 Bq m −2 s −1 ). A vibration load significantly damages the compacted uranium tailings sample structure, resulting in a marked increase in the porosity of the porous media thus forming a channel for radon migration. The results presented here may provide a workable approach for simulating geological dynamic load conditions for radon exhalation studies on uranium tailings impoundment. | Research on radon exhalation characteristics of uranium tailings with cover materials under the coupling load of low-frequency vibration and seepage gradient | 10.1007/s10967-020-07478-x |
2021-01-01 | Owing to suffering the poor recovery of valuable metals and the massive loss of Co metal by the traditional pyrometallurgical technology to process the low-nickel matte. Herein, a sulfate roasting followed by a water leaching Water leaching process was developed as an efficient technology for the simultaneous extraction of Ni, Cu, and Co from low-nickel matte Low-nickel matte in the presence of (NH 4 ) 2 SO 4 additive. The influence of roasting temperature, the dosage of ammonium sulfate Ammonium sulfate , and roasting rules on the leaching efficiency of metals are conducted. Also, the characterizations of phase evolution are complemented with the theoretical analysis of thermodynamic calculation to reveal the mechanism of (NH 4 ) 2 SO 4 added sulfate roasting. The results demonstrate that the (NH 4 ) 2 SO 4 plays a critical role in reducing the reaction temperature and improving the metal selectivity, achieving higher extraction efficiency of Ni, Cu, and Co (90.12%, 81.82%, and 92.45%, respectively), while Fe is only 10.18% and the high selectivity extraction can be achieved. | Synchronous Extraction of Valuable Metals from Low-Nickel Matte Using Ammonium Sulfate Roasting-Water Leaching Process | 10.1007/978-3-030-65493-1_57 |
2021-01-01 | In this paper, the utilization of gas-metal-arc-welding additive manufacturing (GMAWAM) for the repurposing of components was explored. Herein, the GMAWAM process was used to build new low-carbon steel features on an existing low-carbon steel component to obtain a new part with new functionalities. To confirm the internal quality of the new part obtained by such a strategy that is adequate for real applications, its material properties were investigated. The obtained results reveal that the new features (i.e., thin walls) built by GMAWAM possess different microstructure types. The upper region of thin-walled features exhibits lamellar structures, whereas the middle region is characterized by granular structures, and mixed equiaxed and lamellar grains appear in the bottom region. Particularly, the new features have an excellent bonding strength with the existing part. The material properties of GMAWAM-repurposed parts also meet industrial requirements, confirming that the GMAWAM-repurposed parts are adequate with real applications. | On the use of gas-metal-arc-welding additive manufacturing for repurposing of low-carbon steel components: microstructures and mechanical properties | 10.1007/s40194-020-01005-y |
2021-01-01 | In plasma spraying, hydrogen is widely used as a secondary working gas besides argon. In particular under low pressure, there are strong effects on the plasma jet characteristics even by small hydrogen percentages. Under such conditions, fundamental mechanisms like diffusion and recombination are affected while this is less relevant under atmospheric conditions. This was investigated for argon–hydrogen mixtures by optical emission spectroscopy (OES). The small electron densities under the investigated low pressure conditions implied specific difficulties in the application of several OES-based methods which are discussed in detail. Adding hydrogen to the plasma gas effected an increased plasma enthalpy. Moreover, the jet expanded radially as the reactive part of the thermal conductivity was enhanced by recombination of atomic hydrogen so that the shock waves were less reflected at the cold jet rims. In the jet cores, the lowest temperatures were found for the highest hydrogen admixture because the energy consumption due to the dissociation of molecular hydrogen outbalanced the increase of the plasma enthalpy. Variations in the radial temperature profiles were related to the jet structure and radial thermal conductivity. The local hydrogen–argon concentration ratios revealed an accumulation of hydrogen atoms at the jet rims. Clear indications were found, that higher hydrogen contents promoted the fast recombination of electrons and ions. However, it is assumed that the transport properties of the plasma were hardly affected by this, since the electron densities and thus the ionization degrees were generally small due to the low pressure conditions. | How Hydrogen Admixture Changes Plasma Jet Characteristics in Spray Processes at Low Pressure | 10.1007/s11090-020-10143-6 |
2021-01-01 | The article is devoted to the topical issues of increasing the technical readiness of wheeled and tracked equipment in harsh climatic conditions. The high technical readiness of the rolling stock depends on the condition of the batteries. Only the comprehensive application of insulation and heating can ensure the proper level of battery life at negative temperatures. The research proposes a solution for the rolling stock of non-Arctic performance, which under the conditions of operation is not advisable to convert to the Arctic, but it is necessary to ensure high technical readiness for one or two coldest 5-day periods with an air temperature of up to −35°C. The equipment requirements are formulated to solve this problem. The theoretical justification of the battery heater algorithm has been carried out. An algorithm is developed to calculate the parameters of cooling and heating of batteries, cooling and heating time, the amount of heat given, and the received heat. The insulation material for the battery is selected. A test calculation of insulation efficiency on the battery cooling time is performed. The power calculation and the choice of the type of heating element of the battery are carried out. The efficiency of the heater in the low-temperature freezer is checked. | Improving Technical Readiness of Wheeled and Tracked Vehicles in Severe Climatic Conditions | 10.1007/978-3-030-54817-9_88 |
2021-01-01 | Abstract The role of the liquid phase in the formation of the microstructure of a clay tile possessing various physical and engineering characteristics is determined. The effect of the nature of raw materials and ratio of alkali oxides to alkaline-earth oxides on the formation of various calcium-containing crystal phases at low-temperature sintering is determined. | Role of the Liquid Phase in the Formation of the Phase Composition and Characteristics of Structural Cladding Ceramics | 10.1134/S1087659621010132 |
2021-01-01 | Energy deficiency and environmental deterioration are crucial challenges in the current world. About 50% of energy is being wasted due to inefficient energy conversion processes and a lack of execution of reliable recovery technologies. With rapid industrialization and improvement in the standard of life, there exists the enormous potential for recovery of waste heat from industrial processes and transportation systems. The transition of 10% waste heat into electrical power can enhance fuel efficiency by 20%. Apart from enhancing the overall efficiency with the economic outlook, waste energy recovery also helps to mitigate CO 2 emission from thermal systems. In this context, a circular energy management strategy can be applied for effective utilization of waste heat in the form of heat and electrical energy. The effective harnessing of abundant renewable energy sources viz. solar thermal, photovoltaic (PV), biomass, etc., can reduce the dependency on primary energy sources and lead towards sustainable greener future. This review also emphasizes two prominent waste heat recovery technologies viz. Organic Rankine Cycle (ORC) and thermoelectric generator (TEG). While integrating TEG, ORC or other additional features in moving vehicles, the weight has to be taken into account to secure the mass retribution within 5%. | Futuristic Approaches of Low-Grade Industrial Waste Heat Recovery | 10.1007/978-981-16-0159-0_15 |
2021-01-01 | Abstract The behavior of localized plastic flow autowaves in a Fe–Ni–Cr alloy at temperatures 143 K ≤ T ≤ 420 K is considered. The temperature variation of the autowave propagation velocity is studied. It is found that, for the region of low temperatures, the autowave velocity is inversely proportional to the work hardening coefficient and the quadratic dispersion law takes place. The elastoplastic strain invariant does not depend on temperature. | Temperature Dependence of Autowave Characteristics of Localized Plasticity | 10.1134/S1063783421010236 |
2021-01-01 | Intermolecular dynamics in liquids and solutions involves the collective orientational motion of solvent/liquid molecules and intermolecular vibrations. These motions significantly influence the elementary reaction processes in solution. Therefore, the intermolecular dynamics of liquids and solutions is among the most important basic themes in chemistry. The intermolecular dynamics in liquids and solutions occurs in the time domain of approximately tens of femtoseconds (fs) to hundreds of picoseconds (about 10 3 to 10 −1 cm −1 in the frequency domain with the wavenumber unit). Thus, for a detailed understanding of intermolecular vibrations and collective orientational motion in liquids and solutions, observing molecular motions in the low-frequency region (approximately 200 cm −1 or less) is necessary. Dynamic Raman-induced Kerr effect spectroscopy (RIKES) using a fs laser can obtain low-frequency spectra without Rayleigh scattering. In this chapter, the subject of intermolecular vibrations in molecular liquids (MLs) and ionic liquids (ILs) studied by fs-RIKES is overviewed. Studies on the low-frequency spectra of liquids by complementary methods, molecular dynamics (MD) simulations, and THz time-domain spectroscopy (THz-TDS) or far-infrared (far-IR) spectroscopy are also outlined in this chapter. | Intermolecular Vibrations in Aprotic Molecular Liquids and Ionic Liquids | 10.1007/978-981-16-5395-7_7 |
2021-01-01 | Lightweight metal matrix nanocomposites Metal Matrix Nanocomposites (MMnC) (MMnC) could offer distinct advanced properties to light metals due to inherent high temperature stability, high strength, high stiffness, and wear resistance. Production processes have to consider that the movement of particles in the nanoscale range differs from that in the micro and mesoscale range. Nanoparticles Nanoparticle show a slight aggregation behaviour in the casting process compared to larger particles. Here a Lagrangian framework was developed to calculate the conservation equation of momentum for nanoparticle taking into account surface and body forces that act on the particle. Thermophoretic and Brownian forces which play a dominant role in the motion of nanoparticles were implemented to analyse the distribution of nanoparticles in low pressure die casting Low Pressure Die Casting (LPDC) simulations. Strategies to simulate nanoparticle tracking in low pressure die casting were proposed. Verifications were carried out to investigate the motion behaviour using benchmark simulations. The developed model was employed to conduct low pressure die casting simulation and the computational simulation of nanoparticle distributions could be utilized to compare to experimental results from low pressure die casting processes determined by transmission electron microscopy. | Computational Simulation of Nanoparticle Distributions in Metal Matrix Composite Casting Processes | 10.1007/978-3-030-65396-5_25 |
2021-01-01 | Due to the low efficiency and depletion of fossil fuel, it becomes mandatory to integrate two or more cycle in a plant to meet the demand of electricity by general public. The low-temperature organic Rankine cycle is the most promising cycle among all the other thermodynamic cycles to operate on a low-temperature heat sources such as solar, geothermal, waste heat of engine etc for generating an extra power to meet the demand and reduce the high-temperature emissions in environment. This paper investigates the performance of a sub-critical organic Rankine cycle individually using dry, wet and isentropic fluid through first and second law efficiency. The screening of seven working fluids is done based on its physical, chemical and thermal properties. The heat source is a waste heat of recovery generator ranging from 75–85 °C. The result reveals that critical temperature is highly dependent on heat source condition and affects the performance of ORC. | Performance Augmentation of Low-Temperature Sub-critical Organic Rankine Cycle Using First and Second Law-Based Analysis | 10.1007/978-981-15-8704-7_28 |
2021-01-01 | Globally, the pressure mounts towards attaining low carbon emissions in the energy sector, which has propelled the G8 Summit to advocate for radical high technology approaches for cement production. Among the modern technologies recommended, which also offers the techno-economic advantages is the microwave-based curing . Low pressure accelerated microwave heating, also called accelerated dewatering, is an innovative technique that enhances the properties of HSCP. This study has analyzed the effect of this improvement including the impact of the pressure on feed direction, MW cavity, and the different HSPC samples for every MW treatment batch. The initial state of this treatment established the following . First, to evade internal structure cracks, the delay time should precede the setting time ( averagely 30 min after mixing ) . Secondly, the moisture and temperature increase differences within the MW cavity should be minimal. By following low-pressure microwave treatment will significantly improve properties of HSCP by increasing the resistance to drying shrinkage and water permeability. | Use of Microwave-Accelerated Curing Under Low-Pressure in the Production of Ultra-Durability Portland Type I-Portland Cement Pastes | 10.1007/978-3-030-76551-4_8 |
2021-01-01 | Membrane electrode assembly (MEA) is the core component of proton exchange membrane fuel cell, which is composed of proton exchange membrane, cathode and anode catalytic layers and gas diffusion layers. The cost of MEA accounts for more than 60% of that of the total system, and particularly, the cost of platinum (Pt) catalysts accounts for nearly 70% of MEA cost. It has been well recognized that the high cost caused by high Pt loading in MEA Pt-based catalysts is one of the key issues that hinder the commercialization of fuel cells, and thus the most direct way to reduce the cost of fuel cells is to reduce the amount of Pt in the MEA. However, a continuous decrease in the Pt loading in MEA will cause more serious activation overpotential and oxygen transport Oxygen transport problems. In order to solve the above difficulties, on one hand, low Pt electrocatalysts Low Pt electrocatalysts , such as Pt alloy catalysts, Pt core–shell catalysts and shape-controlled Pt-based nanocrystals, have been proposed to improve the catalytic activities in the MEA, and on the other hand, accurately measuring the mass transfer resistance in catalytic layers is conducive to the development of low Pt membrane electrode technology. In this section, the introduction of PEMFCs and the components of MEA including proton exchange membrane (PEM), catalyst layers and gas diffusion layers (GDLs) are then discussed. In addition, low Pt electrocatalysts Low Pt electrocatalysts are our focus. | Proton Exchange Membrane Fuel Cells (PEMFCs) | 10.1007/978-3-662-56070-9_1 |
2021-01-01 | As the consumption of natural resources in today's industrialized society is increasing and the supply of these resources tends to deplete, the search for alternative and environmentally friendly raw materials becomes mandatory . Bamboo is a very abundant resource and presents short growth, carbon sequestration ability, easy processing and good mechanical properties. However, bamboo is hygroscopic material and presents functional gradation of properties along the culm wall thickness. Cracks may occur in bamboo’s wall as a consequence of a radial moisture gradient, that generate stress perpendicularly to natural fiber alignment, and this occurrence may compromise the durability and structural performance of the material. Aiming to minimize these shortcomings and to enhance physical properties, different polymers were used to impregnate samples of Phyllostachys pubescens bamboo through immersion: styrene butadiene rubber (SBR), carboxylated styrene butadiene rubber (XSBR) and polyvinyl alcohol (PVOH). Three temperatures of impregnation were investigated (23, 60 and 100 ºC, and the most effective in relation to polymer penetration and retention was identified. Results of water absorption tests showed that PVOH resulted in better physical behaviour and smaller water absorption values, compared with non impregnated samples. Three-points bending test was carried out employing samples with 20 × 2 × 0.5 cm. The samples were extracted from the internodes of the middle portion of a 3 years old culms. The obtained parameters (bending strength, stiffness and toughness) were compared among the 4 conditions (plain, SBR, XSBR, PVOH) in order to understand how the impregnation process affected the mechanical performance under bending loads. | The Influence of Polymers Impregnation on Bending Behaviour of Phyllostachys pubescens (Mosso) Bamboo | 10.1007/978-3-030-76543-9_6 |
2021-01-01 | The paper presents the solution to a problem associated with the locking equipment in water supply systems destruction on the upper floors of high-rise buildings. After the destruction products, quality study reveals no metallographic defects or rejects in the manufacture, and the hypothesis that the destruction cause is low-cycle material fatigue under the dynamic loads influence, arising due to temperature deformations in the pipeline, is proposed. The paper considers a pipeline scheme, in which a temperature gradient arises in the fluid flow direction. At different temperature strains of the pipeline parts, bending stresses emerge. The cyclic nature of these stresses is determined by the hot and cold water consumption frequency. The pipeline model where the locking equipment was installed is a beam with pinched ends. The bending stresses calculation for this beam is performed using the initial parameter method. The plots of moments and transverse forces in the beam section are plotted. The permissible stress calculation under the dynamic loads action is made. The pipeline section size, within which shut-off equipment can be installed without destruction, is determined. | The Destruction Theory for the Water Supply Systems Locking Equipment Located on the Upper Floors of the High-Rise Buildings | 10.1007/978-3-030-54814-8_80 |
2021-01-01 | Zero waste manufacturing (ZWM) conceptually transforms the economies of nations to a circular economy by employing sustainable technologies in reducing waste to barest minimum possible through the entire value chain. A number of indicators have therefore been proposed by many researchers to assess zero waste management right from producing raw materials to product manufacturing and finally waste disposal. Much attention has been given to waste disposal and recycling in ZWM. However, for better resource efficiency, zero waste index (ZWI) was proposed to quantify energy, material, and water conservation through recycling efforts rather than simply measuring waste diverted from landfills. The most significant influence on the earth is energy generation and consumption. Hence, to limit the exploitation of the earth within its carrying capacity, the zero waste energy index (ZWeI) is hereby proposed to assess and promote energy efficiency in value chain through low-grade energy utilization and waste heat recovery (WHR). The ZWeI is a measure of the energy efficiency in product manufacturing processes and the potential of energy recovery from product waste. In this study, organic Rankine cycle (ORC) technology is being proposed to achieve ZWEI in energy-intensive industries. | Fossil Fuel Combustion, Conversion to Near-Zero Waste Through Organic Rankine Cycle | 10.1007/978-3-030-58675-1_69-1 |
2021-01-01 | Metallic materials can exhibit creep or relaxation effects even at room temperature. For technical applications, this is typically not relevant because the effects are usually assumed to be small and therefore not relevant for the failure of components. However, relaxation effects may become important, particularly with regard to the prediction of the residual stress state or the distortion state arising from shot peening or jigging of components. To investigate the room temperature relaxation behavior quenched and tempered specimens made of 42CrMo4 (AISI/SAE 4140) were deformed up to different total strains with different strain rates. Then the respective total strain was kept constant and the stress relaxation occurring in a hold time up to 1 h was recorded and analyzed. It turns out that even after a relative small plastic deformation significant relaxation effects occur. Regarding the relaxation rate a distinction must be made between short-term and long-term behavior. Typically, the long-term behavior can be described with an exponential approach. Depending on the strain rate, which was used to settle the starting stress, a more or less pronounced short-time relaxation is observed in which the stresses relax faster compared to the long-term behavior. The experimental procedure, the measurements, and the evaluations carried out are presented. The physical reasons for the different relaxation behavior will be discussed. | Room Temperature Stress Relaxation of a Quenched and Tempered Steel | 10.1007/978-3-030-59542-5_6 |
2021-01-01 | Low-temperature reduction of hematite Hematite to metallic iron by hydrogen Hydrogen is an essential process for ironmaking Ironmaking based on the blast furnace Blast furnace and non-blast furnace Blast furnace technologies. In this work, the reduction behaviors Reduction behaviors of Brazilian hematite Hematite in 20%H 2 –80%Ar at 400–570 °C were investigated in a micro-fluidized bed. Results indicate that the effect of the gaseous external diffusion can be eliminated as the gas flow rate reaches 400 mL/min at 500 °C. According to the conversion X , the reaction from hematite Hematite to metallic iron can be divided into two stages, which include the first stage that corresponds to the process of Fe 2 O 3 → Fe 3 O 4 with X < 1/9 and the second stage that corresponds to the reaction of Fe 3 O 4 → Fe. During the reduction process, magnetite is formed gradually and a large number of pores and fissures are observed on the surface of the ore and peripheral part of the unreacted core of hematite Hematite . The rate constants of all individual reactions tend to increase with increasing temperature, and the reaction rate of the entire reduction process is suggested to be determined by the phase boundary reaction. | Reduction Behaviors of Hematite to Metallic Iron by Hydrogen at Low Temperatures | 10.1007/978-3-030-65257-9_11 |
2021-01-01 | Adverse physicochemical environments are significant sources to recover the extreme actinobacterial communities. In these harsh environmental conditions, most mesophilic microbes perish because of the lack of adaptability. However, despite the harsh environments, few types of microbes can still be able to survive and even reproduce at different physicochemically limited conditions, and they are popularly known as extremophiles. The main reason behind this adaptation is due to their abundance in amino acid composition, which influences the protein folding capabilities of these microbes. The current chapter has revealed extreme actinobacteria communities in different hostile environments such as high or low temperature, high salinity, acidic or alkaline conditions, high pressure, and dry-desiccation conditions. One of the distinguishing features of the extremophilic actinobacteria is concerns about their propagation in a broader range of environments. Advancements have been made in developing L-strategy for categorizing the microbes under unfavorable conditions as either highly tolerant or resistant to environmental stress conditions. | Actinobacteria: Basic Adaptation to Harsh Environments | 10.1007/978-981-16-3353-9_5 |
2021-01-01 | A set of transition metal oxides was prepared via a sol-gel synthesis using different metal (Mn, Cu, and Fe) nitrates to ensure a proper manganese to metal ratio in the final product. Specifically, three pure metal oxides (Mn 2 O 3 , CuO, and Fe 2 O 3 ) and mixed oxides (MnCu 15 , MnFe 15 , and MnCu 7.5 Fe 7.5 ) were synthesized and characterized by means of XRD, N 2 -physisorption at −196 °C, H 2 -TPR, FESEM, and XPS techniques. The catalysts were tested for the catalytic oxidation of volatile organic compounds (VOCs) using two probe molecules, namely ethylene and propylene. As a result, the best reaction rates were observed for the MnCu 7.5 Fe 7.5 powder sample and were attributed to the synergistic interactions occurring between the Mn, Cu, and Fe species in the crystalline structure. Similarly, Mn 2 O 3 showed a good catalytic performance. The excellent catalytic activity of the oxides was correlated with the high amount of reactive chemisorbed oxygen species located on the surface, since these species are useful for the oxidation of VOCs. As well, the improvement of the catalytic activity corresponded to the enhanced reducibility of the catalysts at lower temperatures (i.e., better lattice-oxygen mobility) observed during the temperature-programmed reduction studies. | Catalytic Oxidation of Volatile Organic Compounds over Porous Manganese Oxides Prepared via Sol-Gel Method | 10.1007/978-3-030-58934-9_2 |
2021-01-01 | Abstract A method making it possible to form HTS ceramics of non-superconducting coating consisting of self-organizing CuO crystals, whose sizes are less than the coherence length, i.e., within several tens of nanometers, has been developed. It has been shown that the combination of self-organizing structures in the form of whiskers and nanoparticles which arise as a result of combined sintering of YBa 2 Cu 3 O (7– x ) powders and electric arc CuO nanopowders results in a significant increase in the current density and appearance of peak effect at high magnetic fields. Very high current density arises from the complex vortex pinning, where whisker defects provide high pinning energy and nanoparticles suppress flux creep. The morphology of such structures can be controlled by a simple change in the concentration of nanodisperse additives. It has been shown that 20 wt % of CuO additive is optimal. | Investigation of Microstructural Features, Phase Composition, and Magnetic Characteristics of YBCO-Based Composites and Additives of CuO Non-Superconducting Component Prepared in Low-Pressure Arc Discharge Plasma | 10.1134/S2075113321010172 |
2021-01-01 | Purpose : This review analyzes the properties of magnetically active iron(II) and (III) complexes with tridentate ligands, in which the phenomenon of spin-crossover ( SCO ) and thermochromism (color change with temperature change) is observed. The most widely studied systems with SCO are hexacoordinated iron(II, III) complexes with the FeN 6 coordination node. Methodology : To identify and reliably characterize the obtained compounds, were used a combination of various physical and chemical research methods: CHNS; metal analysis by atomic absorption spectroscopy and complexometry, X-ray diffraction, differential scanning calorimetry (DSC), thermogravimetric analysis, electronic (DRS), IR, Messbauer, and NMR (in solution on 1 H) spectroscopy. An important part of this work is the study of the magnetic properties of compounds by static magnetic susceptibility: spin-crossover in iron(II) complexes. Findings : New achievements in the synthesis and research of coordination compounds of iron(II) with tris(pyrazol-1-yl)methane, which exhibit a high-temperature spin-crossover accompanied by a “purple ↔ white” thermochromism, are shown. The analysis of changes in structural parameters during spin transitions is performed. Value : Great progress has been shown in the development of bistable materials containing Fe. | Thermally Induced Spin Crossover in Iron (II, III) Complexes with Tripodal Ligands | 10.1007/978-3-030-69421-0_34 |
2021-01-01 | Raulí is an iconic species of the temperate sub-Antarctic forests due to its hardwood quality of pinkish tones. Because of its ecological and economic relevance, it is under conservation within national parks and being domesticated for plantation purposes. In this chapter, we present the state of the art of the species in Argentina. General features as distribution, biology and uses are firstly presented. Patterns of genetic variation at neutral markers allowed studying the legacy of the glacial ages as well as recent processes shaping the genetic structure. In addition, variation among populations at quantitative traits (phenological, physiological, morphological, architectural and growth rhythm traits) reflect the action of natural selection. Mycorrhizas and other soil fungi have strong relevance for conservation and domestication programmes, and their diversity is described. The domestication programme is dependent on seed productivity restrictions in natural stands, and the regulation of germination was studied through threshold models. The breeding strategy of raulí includes provenance and progeny tests, definition of genetic zones and seed collection areas based on genetic markers and installation of progeny seed orchards. Conservation and management of N. alpina forests in Argentina is finally discussed in the context of its over-exploitation in the past decades, conservation actions and management guidelines. | Raulí (Nothofagus alpina = N. nervosa): The Best Quality Hardwood in Patagonia | 10.1007/978-3-030-56462-9_3 |
2021-01-01 | The investigation explores the possible utilization of low-density polyethylene (LDPE) as a modifier of bitumen. Different concentrations of LDPE (5%, 6%, 7% and 8% by weight of bitumen) were mixed with 80/100 penetration grade bitumen. Rheological tests include penetration, viscosity, ductility, and other characterization techniques X-ray powder diffractometry XRD, infrared spectrophotometer were also used to study the homogeneity and properties of the system. The XRD patterns of normal bitumen and modified bitumen with LDPE showed that the phase transition to a higher crystallinity shows high strength and viscosity while the ductility and penetration are low. The IR peak at 1015 cm −1 in the modified sample showed the increase in bending vibration of the C–H bond and breaking of polyethylene macromolecules. The outcome shows that the exhibition of LDPE changed bitumen blends is better than the normal bitumen. Introduction of LDPE outperformed the conventional bitumen and fulfilled the required performance of the bituminous mixes. In addition, the study reveals that modification made by using LDPE improved the service life. | Use of Low-Density Polyethylene Waste for the Road Construction in Manipur, India | 10.1007/978-981-33-4590-4_8 |
2021-01-01 | Soil with the required engineering properties is the first prerequisite in construction engineering, as the stability of the buildings and structures highly hinges on characteristics of soil by which they are supported. Microbial induced carbonate precipitation (MICP) is a newly developed soil improvement technique that has drawn the great deal of interest among geotechnical and geo-environmental engineers. The mechanism relies on set of biochemical reactions, utilizing bacterial enzyme to produce calcium carbonate bio-cement that could effectively bind the soil particles, leading to enhance the engineering properties of soil. Despite being a novel ground improvement technique, numerous studies have demonstrated that MICP can be a promising alternative for several geotechnical applications. Recently, researchers have started focusing on amending the typical MICP approach by incorporating preeminent materials, so that to enhance the MICP responses. This chapter presents a review on the amendments in MICP made by low-grade chemicals, biopolymers and other salient additives including magnesium ions, fly-ash and fibers. The effects and responses of the above materials in MICP are extensively described and discussed, and some research gaps are also pointed out. Although studies have suggested a wide range of advantages, there are many aspects and challenges on the above subjects are still to be addressed in future works prior to the real field applications. | The Amendments in Typical Microbial Induced Soil Stabilization by Low-Grade Chemicals, Biopolymers and Other Additives: A Review | 10.1007/978-981-16-1706-5_4 |
2021-01-01 | The cost-effective removal of heavy metals from aqueous solution is a major challenge for the scientific community. Heavy metal reduction from aqueous solution using bentonite clay, inorganic coagulants, and their mixture is a cost-effective technique. They are easily available and cheaper compared to the activated carbon, which is widely used but an expensive adsorbent. Bentonite is a clay mineral composed of very fine particles with high opening volume and high specific active site. Thus, it has a significantly high absorption capacity. The metal ion properties, adsorbent dosage, initial concentration, and operating conditions (temperature, pH, contacting time, etc.) are the major parameters for the effective application of raw and modified bentonite. Coagulation is also a traditional technique to minimize metal ions from the bulk solution. Excessive use of inorganic coagulants may result in corrosion and erosion effect on the equipment and excessive generation of sludge volume during coagulation process. Effectiveness of bentonite clay can be enhanced by mixing inorganic coagulants such as sodium carbonate, sulfates and chlorides of aluminum, iron, etc. These coagulants are mixed with the bentonite clay in an optimum ratio to reduce the turbidity and COD of solution. This chapter includes a detailed review of recent work on heavy metal reduction in aqueous system using bentonite clay, inorganic coagulants, and their mixtures. | Removal of Heavy Metals Using Bentonite Clay and Inorganic Coagulants | 10.1007/978-981-15-5901-3_3 |
2021-01-01 | The Mn/Co mixed powders with various Mn/Co molar ratios were prepared by the coprecipitation method and used in low-temperature CO oxidation. The physicochemical characteristics of these powders were characterized using the Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), temperature-programmed reduction (TPR), and scanning electron microscopy (SEM) analyses. The results demonstrated that the Mn/Co molar ratio significantly affected both the textural and catalytic properties and the sample with a Mn/Co = 1:1 possessed a BET area of 123.7 m 2 g −1 with a small mean pore size of 6.44 nm. The catalytic results revealed that the pure cobalt and manganese catalysts possessed the low catalytic activity and the pure Co catalyst is not active at temperatures lower than 140 °C. The highest catalytic activity was observed for the catalyst with a Mn/Co = 1. The obtained results showed that the incorporation of Pd into the Mn/Co catalyst significantly enhanced the catalytic activity for oxidation of carbon monoxide and the highest CO conversion was observed for the catalyst with 1 wt.% Pd and this catalyst exhibited a CO conversion of 100% at 80 ° C. | Preparation of the Mn/Co mixed oxide catalysts for low-temperature CO oxidation reaction | 10.1007/s11356-020-10484-x |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.