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2006-06-27
Fe adatoms along Bi lines on H/Si(001): Patterning atomic magnetic chains
The stability, electronic and magnetic properties of Fe atoms adsorbed on the self-assembled Bi-dimer lines nanostructure on the H/Si(001) surface are addressed by spin-density functional calculations. Our results show that Fe adatoms are much more stable on sites closer to the Bi nanolines being able to form one-dimen...
0606707v2
2006-08-14
Thermal relaxation of magnetic clusters in amorphous Hf_{57}Fe_{43} alloy
The magnetization processes in binary magnetic/nonmagnetic amorphous alloy Hf_{57}Fe_{43} are investigated by the detailed measurements of magnetic hysteresis loops, temperature dependence of magnetization, relaxation of magnetization and magnetic ac susceptibility, including a nonlinear term. Blocking of magnetic mome...
0608307v3
2006-09-15
Surfactant effects in monodisperse magnetite nanoparticles of controlled size
Monodisperse magnetite Fe3O4 nanoparticles of controlled size within 6 and 20 nm in diameter were synthesized by thermal decomposition of an iron organic precursor in an organic medium. Particles were coated with oleic acid. For all samples studied, saturation magnetization Ms reaches the expected value for bulk magnet...
0609384v1
2006-10-18
A new type of temperature driven reorientation transition in magnetic thin films
We present a new type of temperature driven spin reorientation transition (SRT) in thin films. It can occur when the lattice and the shape anisotropy favor different easy directions of the magnetization. Due to different temperature dependencies of the two contributions the effective anisotropy may change its sign and ...
0610504v1
2006-11-09
New ultrasmall iron-oxide nanoparticles with high magnetisation as potential T1-MRI contrast agents for Molecular Imaging
Here we report on the synthesis of very small gamma-Fe2O3 nanoparticles (5 nm) presenting very narrow particle size distribution and exceptionally high saturation magnetisation. The synthesis has been carried out in an organic medium with subsequent transfer to an aqueous solution at physiological pH. The structural an...
0611243v1
2006-12-10
Substituting the main group element in cobalt - iron based Heusler alloys: Co$_2$FeAl$_{1-x}$Si$_x$
This work reports about electronic structure calculations for the Heusler compound Co$_2$FeAl$_{1-x}$Si$_x$. Particular emphasis was put on the role of the main group element in this compound. The substitution of Al by Si leads to an increase of the number of valence electrons with increasing Si content and may be seen...
0612241v1
2006-12-23
Magnetic phase diagram of Ce2Fe17
Rare-earth-based permanent-magnet materials rich in iron have relatively low ferromagnetic ordering temperatures. This is believed to be due to the presence of antiferromagnetic exchange interactions, besides the ferromagnetic interactions responsible for the magnetic order. The magnetic properties of Ce2Fe17 are anoma...
0612603v1
2007-01-02
Resonant soft x-ray magnetic scattering from the 4f and 3d electrons in DyFe(4)Al(8)
Soft x-ray resonant scattering has been used to examine the charge and magnetic interactions in the cycloidal antiferromagnetic compound \dyfeal. By tuning to the Dy $M_4$ and $M_5$ absorption edges and the Fe L(2) and L(3) absorption edges we can directly observe the behavior of the Dy 4f and Fe 3d electron shells. Ma...
0701034v1
2007-01-26
Use of Superparamagnetic Nanoparticle/Block Copolymer Electrostatic Complexes as Contrast Agents in Magnetic Resonance Imaging
During the past years we have investigated the complexation between nanocolloids and oppositely charged polymers. The nanocolloids examined were ionic surfactant micelles and inorganic oxide nanoparticles. For the polymers, we used homopolyelectrolytes and block copolymers with linear and comb architectures. In general...
0701663v1
2007-02-23
Spectral and Fermi surface properties from Wannier interpolation
We present an efficient first-principles approach for calculating Fermi surface averages and spectral properties of solids, and use it to compute the low-field Hall coefficient of several cubic metals and the magnetic circular dichroism of iron. The first step is to perform a conventional first-principles calculation a...
0702554v1
2007-03-15
Theoretical introduction to express way of the complex determination of the thermophysical parameters of metals
A method to measure thermophysical characteristics (TPC) of conductive materials is described. The method is based upon controlled bulk (e.g., Ohmic) heating and measurement of the averaged over the volume of a sample temperature and the temperature of the surface of a sample. To measure averaged over a sample volume t...
0703392v2
1999-01-15
The Atmospheric Neutrino Flavor Ratio from a 3.9 Fiducial Kiloton-Year Exposure of Soudan 2
We report a measurement of the atmospheric neutrino flavor ratio, R, using a sample of quasi-elastic neutrino interactions occurring in an iron medium. The flavor ratio (tracks/showers) of atmospheric neutrinos in a 3.9 fiducial kiloton-year exposure of Soudan 2 is 0.64 +- 0.11 (stat.) +- 0.06 (syst.) of that expected....
9901024v1
1999-12-14
Longitudinal Hadronic Shower Development in a Combined Calorimeter
This work is devoted to the experimental study of the longitudinal hadronic shower development in the ATLAS barrel combined prototype calorimeter consisting of the lead-liquid argon electromagnetic part and the iron-scintillator hadronic part. The results have been obtained on the basis of the 1996 combined test beam d...
9912028v1
2000-01-05
Search for Nucleon Decay with Final States l+ eta, nubar eta, and nubar pi+,0 Using Soudan 2
We have searched for nucleon decay into five two-body final states using a 4.4 kiloton-year fiducial exposure of the Soudan 2 iron tracking calorimeter. For proton decay into the fully visible final states mu+ eta and e+ eta, we observe zero and one event, respectively, that satisfy our search criteria for nucleon deca...
0001015v1
2000-01-13
Neutrino Oscillation Appearance Experiment using Nuclear Emulsion and Magnetized Iron
This report describes an apparatus that could be used to measure both the identity and charge of an outgoing lepton in a charged current neutrino interaction. This capability in a massive detector would allow the most comprehensive set of neutrino oscillation physics measurements. By measuring the six observable transi...
0001035v1
2000-04-06
Hadron Energy Reconstruction for the ATLAS Barrel Prototype Combined Calorimeter in the Framework of the Non-parametrical Method
Hadron energy reconstruction for the Atlas barrel prototype combined calorimeter, consisting of the lead-liquid argon electromagnetic part and the iron-scintillator hadronic part, in the framework of the non-parametrical method has been fulfilled. This method uses only the known e/h ratios and the electron calibration ...
0004009v1
2001-04-02
Hadron Energy Reconstruction for the ATLAS Calorimetry in the Framework of the Non-parametrical Method
This paper discusses hadron energy reconstruction for the ATLAS barrel prototype combined calorimeter (consisting of a lead-liquid argon electromagnetic part and an iron-scintillator hadronic part) in the framework of the non-parametrical method. The non-parametrical method utilizes only the known $e/h$ ratios and the ...
0104002v2
2001-04-11
New calibrations and time stability of the response of the INTERCAST CR-39
We present new calibrations of different production batches (from 1989 to 1999) of the INTERCAST CR-39, using the BNL-AGS 1 A GeV iron beam. The comparison with previous results, obtained with the 158 A GeV lead beam from the CERN-SPS shows that, while each production batch has a different calibration curve (mainly due...
0104022v1
2001-05-22
Extraction of R=sigma_L/sigma_T from CCFR Neutrino and Antinetrino Differential Cross Sections
We report on the extraction of R=sigam_L/sigma_T from CCFR neutrino and antineutrino-Iron differential cross sections. R as measured in neutrno scattering is in agreement with $R$ as measured in muon and electron scattering. All data on R for Q2 > 1 GeV2 are in agreement with a NNLO QCD calculation which uses NNLO PDFs...
0105067v1
2002-11-07
Design and test results of the AMS RICH detector
The AMS-02 detector will operate for at least 3 years on the International Space Station, measuring cosmic ray spectra at about 400 km above sea level over a wide range of geomagnetic latitude. The proximity focusing ring imaging \v{C}erenkov counter of AMS-02 will measure the particle velocity $\beta$ with $\approx ...
0211018v1
2006-07-31
Machine-Related Backgrounds in the SiD Detector at ILC
With a multi-stage collimation system and magnetic iron spoilers in the tunnel, the background particle fluxes on the ILC detector can be substantially reduced. At the same time, beam-halo interactions with collimators and protective masks in the beam delivery system create fluxes of muons and other secondary particles...
0608001v1
1992-11-19
Recent Work on Standard Solar Models
Recent results on standard solar models are reviewed. I shall summarize briefly three of the themes that I stressed at the Neutrino '92 Conference: 1) Different solar model codes give the same answers when the same input data are used; 2) Improved calculations of standard solar models include helium diffusion, the Live...
9211280v1
1997-09-09
Neutrino-photon reactions in astrophysics and cosmology
At energies above the threshold for $W$ production the process $\nu \gamma \to l W^+$ is competive with $\nu \nu$ scattering at the same center of mass energies. In a cosmological setting, absorption of ultra high energy neutrinos by the microwave photon background is comparable to absorption by the neutrino background...
9709290v1
1997-12-07
Off-shell Corrections and Moments of the Deep Inelastic Nuclear Structure Functions
We present an improved method for handling off-shell effects in deep inelastic nuclear scattering. With a firm understanding of the effects of the nuclear wave function, including these off-shell corrections as well as binding and nucleon-nucleon correlations, we can begin to examine the role of QCD in nuclei through a...
9712286v1
1998-05-07
Measurement of Atmospheric Neutrino Oscillations with a High-Density Detector
We propose an experiment to test the hypothesis that the reported anomaly on atmospheric neutrino fluxes is due to nu_mu <-> nu_x oscillations. It will rely both on a disappearance technique, exploiting the method of the dependence of the event rate on L/E, which was recently shown to be effective for detection of neut...
9805249v2
2000-12-13
CP-violation in 3- and 4-family at the Neutrino Factory
The leptonic CP-violating phase $\delta$ can be measured with a Neutrino Factory with $2 \times 10^{20} $ useful muons per year, if the solar neutrino problem is solved by the LMA-MSW solution, with $\Delta m_{12}^2 \ge 2 \times 10^{-5}$ eV$^2$ (in this analysis a 40 kT magnetized iron detector is considered, taking in...
0012153v1
2000-12-27
Propagation of Muons and Taus at High Energies
The photonuclear contribution to charged lepton energy loss has been re-evaluated taking into account HERA results on real and virtual photon interactions with nucleons. With large $Q^2$ processes incorporated, the average muon range in rock for muon energies of $10^9$ GeV is reduced by only 5% as compared with the sta...
0012350v1
2001-07-27
Extragalactic Sources for Ultra High Energy Cosmic Ray Nuclei
In this article we examine the hypothesis that the highest energy cosmic rays are complex nuclei from extragalactic sources. Under reasonable physical assumptions, we show that the nearby metally rich starburst galaxies (M82 and NGC 253) can produce all the events observed above the ankle. This requires diffusion of pa...
0107287v4
2002-06-04
The silver channel at the Neutrino Factory
We notice that looking for $\nu_e \to \nu_\tau$ at the same time as $\nu_e \to \nu_\mu$ oscillations could significantly help to reduce the errors in the leptonic CP-violating phase $\delta$ measurement. We show how the $\nu_e \to \nu_\mu$ (``golden'') and $\nu_e \to \nu_\tau$ (``silver'') transitions observed at an OP...
0206034v1
2002-07-12
Possible Studies of Parton Distribution Functions at JHF
We discuss possible studies of parton distribution functions (PDFs) in the nucleon and nuclei at the Japan Hadron Facility (JHF). First, the PDFs could be investigated by the 50 GeV primary proton facility. The distributions at medium x are determined, for example, by Drell-Yan measurements. Second, there are feasibili...
0207151v1
2002-09-18
Modified Paschos-Wolfenstein relation and extraction of weak mixing angle sin^2 theta_W
The NuTeV collaboration reported anomalously large weak mixing angle sin^2 theta_W in comparison with the standard model prediction. Neutrino and antineutrino charged- and neutral-current events are analyzed for extracting sin^2 theta_W. Although the Paschos-Wolfenstein relation is not directly used in the analysis, it...
0209200v2
2003-01-18
Charge Symmetry Violating Contributions to Neutrino Reactions
The NuTeV group has measured charged and neutral current reactions for neutrinos on iron targets. Ratios of these cross sections provide an independent measurement of the Weinberg angle. The NuTeV value for sin^2 theta_W is three standard deviations larger than the value measured in other electroweak processes. By revi...
0301147v3
2003-05-16
The synergy of the golden and silver channels at the Neutrino Factory
We deepen the study of the so-called ``silver channel'' $\nu_e \to \nu_\tau$ \cite{Donini:2002rm} and of its relevance to solve some of the ambiguities that can arise in the simultaneous measurement of $(\theta_{13},\delta)$ at the Neutrino Factory by presenting in full detail the characteristics of the considered OPER...
0305185v1
2003-06-06
Supernova Neutrinos, Neutrino Oscillations, and the Mass of the Progenitor Star
We investigate the initial progenitor mass dependence of the early-phase neutrino signal from supernovae taking neutrino oscillations into account. The early-phase analysis has advantages in that it is not affected by the time evolution of the density structure of the star due to shock propagation or whether the remnan...
0306056v1
2003-07-08
Nuclear modification of structure functions in lepton scattering
We discuss nuclear structure functions in lepton scattering including neutrino reactions. First, the determination of nuclear parton distribution functions is explained by using the data of electron and muon deep inelastic scattering and those of Drell-Yan processes. Second, NuTeV sin^2 theta_W anomaly is discussed by ...
0307105v1
2004-10-19
Detecting matter effects in long baseline experiments
Experiments strongly suggest that the flavour mixing responsible for the atmospheric neutrino anomaly is very close to being maximal. Thus, it is of great theoretical as well as experimental importance to measure any possible deviation from maximality. In this context, we reexamine the effects of matter interactions in...
0410266v1
2004-12-20
Nuclear modification difference between u_v and d_v distributions and its relation to NuTeV sin^2 theta_W anomaly
We investigate a possible nuclear correction to the NuTeV measurement of the weak-mixing angle sin^2 theta_W. In particular, a nuclear modification difference between u_v and d_v distributions contributes to the NuTeV measurement with the iron target. First, the modification differenceis determined by a chi^2 analysis ...
0412284v2
2005-11-10
Perspectives for a neutrino program based on the upgrades of the CERN accelerator complex
In this paper, we discuss the possibilities offered to neutrino physics by the upgrades of the CERN accelerator complex. Emphasis is on the physics reach of a medium $\gamma$ (350-580) $\beta$-beam that fully exploits the improvements in the CERN accelerator complex for the luminosity/energy upgrade of the LHC. We show...
0511134v2
2006-09-25
Probing Lepton Number Violating Interactions with Beta-beams
We show that a detector placed near a beta-beam storage ring can probe lepton number violating interactions, as predicted by supersymmetric theories with R-parity non-conservation. In the presence of such interactions, nu_tau can be produced during beta-decay leading to tau leptons through weak interactions. Alternativ...
0609252v2
2006-10-16
The mass hierarchy with atmospheric neutrinos at INO
We study the neutrino mass hierarchy at the magnetized Iron CALorimeter (ICAL) detector at India-based Neutrino Observatory with atmospheric neutrino events generated by the Monte Carlo event generator Nuance. We judicially choose the observables so that the possible systematic uncertainties can be reduced. The resolut...
0610196v3
2006-10-25
Neutrino mass hierarchy and $θ_{13}$ with a magic baseline beta-beam experiment
We underscore the physics advantage of an experiment where neutrinos produced in a beta-beam facility at CERN are observed in a large magnetized iron calorimeter (ICAL) at the India-based Neutrino Observatory (INO). The CERN-INO distance is close to the so-called "magic" baseline which helps evade some of the parameter...
0610333v2
2007-02-18
A GEANT-based study of atmospheric neutrino oscillation parameters at INO
We have studied the dependence of the allowed space of the atmospheric neutrino oscillation parameters on the time of exposure for a magnetized Iron CALorimeter (ICAL) detector at the India-based Neutrino Observatory (INO). We have performed a Monte Carlo simulation for a 50 kTon ICAL detector generating events by the ...
0702180v3
2007-03-20
Neutrino hierarchy from CP-blind observables with high density magnetized detectors
High density magnetized detectors are well suited to exploit the outstanding purity and intensities of novel neutrino sources like Neutrino Factories and Beta Beams. They can also provide independent measurements of leptonic mixing parameters through the observation of atmospheric muon-neutrinos. In this paper, we disc...
0703209v3
1996-08-18
M-Theory (the Theory Formerly Known as Strings)
Superunification underwent a major paradigm shift in 1984 when eleven-dimensional supergravity was knocked off its pedestal by ten-dimensional superstrings. This last year has witnessed a new shift of equal proportions: perturbative ten-dimensional superstrings have in their turn been superseded by a new non-perturbati...
9608117v3
2002-10-03
Critical analyses of order parameter and phase transitions at high density in Gross-Neveu model
By critical analyses of the order parameter of symmetry breaking, we have researched the phase transitions at high density in D=2 and D=3 Gross-Neveu (GN) model and shown that the gap equation obeyed by the dynamical fermion mass has the same effectivenesss as the effective potentials for such analyses of all the secon...
0210023v3
1999-10-18
A high-precision polarimeter
We have built a polarimeter in order to measure the electron beam polarization in hall C at JLAB. Using a superconducting solenoid to drive the pure-iron target foil into saturation, and a symmetrical setup to detect the Moller electrons in coincidence, we achieve an accuracy of <1%. This sets a new standard for Moller...
9910013v1
2002-11-25
The Single-Particle Structure of Neutron-Rich Nuclei of Astrophysical Interest at the Ornl Hribf
The rapid nuetron-capture process (r process) produces roughly half of the elements heavier than iron. The path and abundances produced are uncertain, however, because of the lack of nuclear strucure information on important neutron-rich nuclei. We are studying nuclei on or near the r-process path via single-nucleon tr...
0211027v1
2003-07-11
Low-Q scaling, duality, and the EMC effect
High energy lepton scattering has been the primary tool for mapping out the quark distributions of nucleons and nuclei. Data on the proton and deuteron have shown that there is a fundamental connection between the low and high energy regimes, referred to as quark-hadron duality. We present the results of similar studie...
0307012v3
2005-11-28
Cosmogenic activation of Germanium and its reduction for low background experiments
Production of $^{60}$Co and $^{68}$Ge from stable isotopes of Germanium by nuclear active component of cosmic rays is a principal background source for a new generation of $^{76}$Ge double beta decay experiments like GERDA and Majorana. The biggest amount of cosmogenic activity is expected to be produced during transpo...
0511049v1
2006-04-06
Level density of $^{56}$Fe and low-energy enhancement of $γ$-strength function
The $^{55}$Mn$(d,n)^{56}$Fe differential cross section is measured at $E_d=7$ MeV\@. The $^{56}$Fe level density obtained from neutron evaporation spectra is compared to the level density extracted from the $^{57}$Fe$(^3$He,$\alpha\gamma)^{56}$Fe reaction by the Oslo-type technique. Good agreement is found between the ...
0604002v1
1996-01-30
Temperature Dependence of Pair Correlations in Nuclei in the Iron-Region
We use the shell model Monte Carlo approach to study thermal properties and pair correlations in $^{54,56,58}$Fe and in $^{56}$Cr. The calculations are performed with the modified Kuo-Brown interaction in the complete $1p0f$ model space. We find generally that the proton-proton and neutron-neutron $J=0$ pairing correla...
9601047v1
1997-11-21
Approximate Treatment of Lepton Distortion in Charged-Current Neutrino Scattering from Nuclei
The partial-wave expansion used to treat the distortion of scattered electrons by the nuclear Coulomb field is simpler and considerably less time-consuming when applied to the production of muons and electrons by low and intermediate-energy neutrinos. For angle-integrated cross sections, however, a modification of the ...
9711045v1
1998-01-08
Electron capture on iron group nuclei
We present Gamow-Teller strength distributions from shell model Monte Carlo studies of fp-shell nuclei that may play an important role in the pre-collapse evolution of supernovae. We then use these strength distributions to calculate the electron-capture cross sections and rates in the zero-momentum transfer limit. We ...
9801012v1
1998-03-11
Shell model calculation of the beta- and beta+ partial halflifes of 54Mn and other unique second forbidden beta decays
The nucleus 54Mn has been observed in cosmic rays. In astrophysical environments it is fully stripped of its atomic electrons and its decay is dominated by the beta- branch to the 54Fe ground state. Application of 54Mn based chronometer to study the confinement of the iron group cosmic rays requires knowledge of the co...
9803032v1
2000-03-08
Level Densities by Particle-Number Reprojection Monte Carlo Methods
A particle-number reprojection method is applied in the framework of the shell model Monte Carlo approach to calculate level densities for a family of nuclei using Monte Carlo sampling for a single nucleus. In particular we can also calculate level densities of odd-even and odd-odd nuclei despite a new sign problem int...
0003015v1
2002-08-12
Liquid-Gas Phase Transition of Supernova Matter and Its Relation to Nucleosynthesis
We investigate the liquid-gas phase transition of dense matter in supernova explosion by the relativistic mean field approach and fragment based statistical model. The boiling temperature is found to be high (T_{boil} >= 0.7 MeV for rho_B >= 10^{-7} fm^{-3}), and adiabatic paths are shown to go across the boundary of c...
0208020v1
2002-11-08
Nuclear Reactions Important in Alpha-Rich Freezeouts
The alpha-rich freezeout from equilibrium occurs during the core-collapse explosion of a massive star when the supernova shock wave passes through the Si-rich shell of the star. The nuclei are heated to high temperature and broken down into nucleons and alpha particles. These subsequently reassemble as the material exp...
0211022v1
2003-03-18
Nuclear level statistics: extending the shell model theory to higher temperatures
The Shell Model Monte Carlo (SMMC) approach has been applied to calculate level densities and partition functions to temperatures up to ~ 1.5 - 2 MeV, with the maximal temperature limited by the size of the configuration space. Here we develop an extension of the theory that can be used to higher temperatures, taking i...
0303040v1
2005-06-17
Charged Lepton Production from Iron Induced by Atmospheric Neutrinos
The charged current lepton production induced by neutrinos in $^{56}Fe$ nuclei has been studied. The calculations have been done for the quasielastic as well as the inelastic reactions assuming $\Delta$ dominance and take into account the effect of Pauli blocking, Fermi motion and the renormalization of weak transition...
0506057v1
2005-08-13
The nuclear moment of inertia and spin distribution of nuclear levels
We introduce a simple model to calculate the nuclear moment of inertia at finite temperature. This moment of inertia describes the spin distribution of nuclear levels in the framework of the spin-cutoff model. Our model is based on a deformed single-particle Hamiltonian with pairing interaction and takes into account f...
0508027v1
2000-08-18
An ECR hydrogen negative ion source at CEA/Saclay: preliminary results
The development of a high intensity negative ion source is part of a considerably larger activity presently undergoing at CEA Saclay in the field of high intensity linear accelerators. Preliminary studies toward the construction of a 2.45 GHz ECR H- ion source have been performed for few months. This new test bench tak...
0008143v1
2003-05-09
The particle-in-cell model for ab initio thermodynamics: implications for the elastic anisotropy of the Earth's inner core
We assess the quantitative accuracy of the particle-in-cell (PIC) approximation used in recent ab initio predictions of the thermodynamic properties of hexagonal-close-packed iron at the conditions of the Earth's inner core. The assessment is made by comparing PIC predictions for a range of thermodynamic properties wit...
0305033v2
2004-11-19
New applications of Equinox code for real-time plasma equilibrium and profile reconstruction for tokamaks
Recent development of real-time equilibrium code Equinox [1] using a fixed-point algorithm [2] allow major plasma magnetic parameters to be identified in real-time, using rigorous analytical method. The code relies on the boundary flux code providing flux values on the first wall of vacuum vessel. By means of least-squ...
0411181v1
2006-01-04
Simulation Studies of Delta-ray Backgrounds in a Compton-Scatter Transition Radiation Detector
In order to evaluate the response to cosmic-ray nuclei of a Compton-Scatter Transition Radiation Detector in the proposed ACCESS space-based mission, a hybrid Monte Carlo simulation using GEANT3 and an external transition radiation (TR) generator routine was constructed. This simulation was employed to study the effect...
0601020v1
2006-11-22
Efficient Degradation and Expression Prioritization with Small RNAs
We build a simple model for feedback systems involving small RNA (sRNA) molecules based on the iron metabolism system in the bacterium E. coli, and compare it with the corresponding system in H. pylori which uses purely transcriptional regulation. This reveals several unique features of sRNA based regulation that could...
0611069v3
2007-04-06
Millimeter-Thick Single-Walled Carbon Nanotube Forests: Hidden Role of Catalyst Support
A parametric study of so-called "super growth" of single-walled carbon nanotubes(SWNTs) was done by using combinatorial libraries of iron/aluminum oxide catalysts. Millimeter-thick forests of nanotubes grew within 10 min, and those grown by using catalysts with a thin Fe layer (about 0.5 nm) were SWNTs. Although nanotu...
0704.0915v1
2007-04-11
Physical parameters of evolved stars in clusters and in the field from line-depth ratios
We present a high-resolution spectroscopic analysis of two samples of evolved stars selected in the field and in the intermediate-age open cluster IC 4651, for which detailed measurements of chemical composition were made in the last few years. Applying the Gray's method based on ratios of line depths, we determine the...
0704.1462v1
2007-04-13
Spectrum of cosmic rays, produced in supernova remnants
Nonlinear kinetic theory of cosmic ray (CR) acceleration in supernova remnants is employed to calculate CR spectra. The magnetic field in SNRs is assumed to be significantly amplified by the efficiently accelerating nuclear CR component. It is shown that the calculated CR spectra agree in a satisfactory way with the ex...
0704.1715v1
2007-04-16
Single pion electro-- and neutrinoproduction on heavy targets
We present a calculation of single pion electroproduction cross sections on heavy targets in the kinematic region of the Delta(1232) resonance. Final state interactions of the pions are taken into account using the pion multiple scattering model of Adler, Nussinov and Paschos (ANP model). For electroproduction and neut...
0704.1991v1
2007-04-17
Maximum Entropy for Gravitational Wave Data Analysis: Inferring the Physical Parameters of Core-Collapse Supernovae
The gravitational wave signal arising from the collapsing iron core of a Type II supernova progenitor star carries with it the imprint of the progenitor's mass, rotation rate, degree of differential rotation, and the bounce depth. Here, we show how to infer the gravitational radiation waveform of a core collapse event ...
0704.2157v2
2007-05-09
Quark-nova explosion inside a collapsar: application to Gamma Ray Bursts
If a quark-nova occurs inside a collapsar, the interaction between the quark-nova ejecta (relativistic iron-rich chunks) and the collapsar envelope, leads to features indicative of those observed in Gamma Ray Bursts. The quark-nova ejecta collides with the stellar envelope creating an outward moving cap (Gamma ~ 1-10...
0705.1240v3
2007-05-17
Applications of nanoparticles of gamma Fe2O3 for hyperthermia in E.coli by Nd:YAG laser
The paper explores the use of nanoparticles of gamma Fe2O3 for hyperthermia treatment of living organisms by absorption of 1064 nm radiations from Nd:YAG laser. Escherichia coli cells have been used as the model system for demonstrating the effect wherein lysine is used as an interface between the cell walls and the na...
0705.2523v1
2007-05-21
Room temperature spin polarized magnetic semiconductor
Alternating layers of granular Iron (Fe) and Titanium dioxide (TiO$_{2-\delta}$) were deposited on (100) Lanthanum aluminate (LaAlO$_3$) substrates in low oxygen chamber pressure using a controlled pulsed laser ablation deposition technique. The total thickness of the film was about 200 nm. The films show ferromagnetic...
0705.2993v1
2007-05-30
Epitaxial thin films of multiferroic Bi2FeCrO6 with B-site cationic order
Epitaxial thin films of Bi2FeCrO6 have been synthesized by pulsed laser deposition on SrRuO3 on (100)- and (111)-oriented SrTiO3 substrates. Detailed X-ray diffraction and cross-section transmission electron microscopy analysis revealed a double perovskite crystal structure of the Bi2FeCrO6 epitaxial films very similar...
0705.4390v1
2007-06-04
Sum-rules for electron energy-loss near-edge spectra
We derive four sum-rule expressions for spectra measured in electron energy-loss near edge structure experiments. These sum-rules permit the determination spin and orbital magnetic moments, spin-orbit interaction and number of states, analogously to the sum rules of x-ray magnetic circular dichroism. The derivation of ...
0706.0402v2
2007-06-14
Molecular opacities for low-mass metal-poor AGB stars undergoing the Third Dredge Up
The concomitant overabundances of C, N and s-process elements are commonly ascribed to the complex interplay of nucleosynthesis, mixing and mass loss taking place in Asymptotic Giant Branch stars. At low metallicity, the enhancement of C and/or N may be up to 1000 times larger than the original iron content and signifi...
0706.2100v1
2007-06-18
The Spectrum of the Black Hole X-ray Nova V404 Cygni in Quiescence as Measured by XMM-Newton
We present XMM observations of the black hole X-ray nova V404 Cygni in quiescence. Its quiescent spectrum can be best fitted by a simple power-law with slope 2. The spectra are consistent with that expected for the advection-dominated accretion flow (ADAF). V404 Cyg was roughly equal in luminosity compared to the previ...
0706.2652v1
2007-06-20
Optical spectroscopy of RU Cam, a pulsating carbon star
We analysed the high resolution spectra of a RU Cam, classified as W Vir type star. The atmospheric parameters of RU Cam were estimated Teff=5250K and log g=1.0. The hydrogen deficiency of RU Cam was not confirmed. The iron abundance, [Fe/H]=-0.37, is close to the solar one. Abundances of most other elements are also c...
0706.2969v1
2007-06-20
Neutrino-driven explosions twenty years after SN1987A
The neutrino-heating mechanism remains a viable possibility for the cause of the explosion in a wide mass range of supernova progenitors. This is demonstrated by recent two-dimensional hydrodynamic simulations with detailed, energy-dependent neutrino transport. Neutrino-driven explosions were not only found for stars i...
0706.3056v1
2007-07-18
Charge Order Superstructure with Integer Iron Valence in Fe2OBO3
Solution-grown single crystals of Fe2OBO3 were characterized by specific heat, Mossbauer spectroscopy, and x-ray diffraction. A peak in the specific heat at 340 K indicates the onset of charge order. Evidence for a doubling of the unit cell at low temperature is presented. Combining structural refinement of diffraction...
0707.2743v1
2007-07-27
Magnetic Field Generation in Planets and Satellites by Natural Nuclear Fission Reactors
One of the most fundamental problems in physics has been to understand the nature of the mechanism that generates the geomagnetic field and the magnetic fields of other planets and satellites. For decades, the dynamo mechanism, thought to be responsible for generating the geomagnetic field and other planetary magnetic ...
0707.4161v4
2007-08-01
Abundances on the Main Sequence of Omega Centauri
Abundance ratios of carbon, nitrogen and strontium relative to iron, calculated using spectrum synthesis techniques, are given for a sample of main sequence and turnoff stars that belong to the globular cluster omega Centauri. The variations of carbon, nitrogen and/or strontium show several different abundance patterns...
0708.0096v1
2007-08-01
The 4th Concept Detector for the International Linear Collider
The 4th Concept detector presently being designed for the International Linear Collider introduces several innovations in order to achieve the necessary experimental goal of a detecter that is 2-to-10 times better than the already excellent SLC and LEP detectors. We introduce a dual-readout calorimeter system, a cluste...
0708.0142v2
2007-08-01
First-principles thermal equation of state and thermoelasticity for hcp Fe under high pressures
We investigate the equation of state and elastic properties of nonmagnetic hcp iron at high pressures and high temperatures using the first principles linear response linear-muffin-tin-orbital method in the generalized-gradient approximation. We calculate the Helmholtz free energy as a function of volume, temperature, ...
0708.0183v1
2007-08-03
Strong spin-orbit induced Gilbert damping and g-shift in iron-platinum nanoparticles
The shape of ferromagnetic resonance spectra of highly dispersed, chemically disordered Fe_{0.2}Pt_{0.8} nanospheres is perfectly described by the solution of the Landau-Lifshitz-Gilbert (LLG) equation excluding effects by crystalline anisotropy and superparamagnetic fluctuations. Upon decreasing temperature, the LLG d...
0708.0463v1
2007-08-06
Emission Lines in X-ray Spectra of Clusters of Galaxies
Emission lines in X-ray spectra of clusters of galaxies reveal the presence of heavy elements in the diffuse hot plasma (the Intra Cluster Medium, or ICM) in virial equilibrium in the dark matter potential well. The relatively simple physical state of the ICM allows us to estimate, with good accuracy, its thermodynamic...
0708.0674v1
2007-08-29
A Deep Chandra Observation of Kepler's Supernova Remnant: A Type Ia Event with Circumstellar Interaction
We present initial results of a 750 ks Chandra observation of the remnant of Kepler's supernova of AD 1604. The strength and prominence of iron emission, together with the absence of O-rich ejecta, demonstrate that Kepler resulted from a thermonuclear supernova, even though evidence for circumstellar interaction is als...
0708.3858v1
2007-08-31
Stellar Models and Yields of Asymptotic Giant Branch Stars
We present stellar yields calculated from detailed models of low and intermediate-mass asymptotic giant branch (AGB) stars. We evolve models with a range of mass from 1 to 6Msun, and initial metallicities from solar to 1/200th of the solar metallicity. Each model was evolved from the zero age main sequence to near the ...
0708.4385v2
2007-09-03
X-ray reflection in accreting stellar-mass black hole systems
The X-ray spectra of accreting stellar-mass black hole systems exhibit spectral features due to reflection, especially broad iron K alpha emission lines. We investigate the reflection by the accretion disc that can be expected in the high/soft state of such a system. First, we perform a self-consistent calculation of t...
0709.0270v1
2007-09-21
Self-assembly of polymers or copolymers and ferrofluids leading to either 1-d, 2-d or 3-d aggregates decorated with magnetic nanoparticles
A novel type of hybrid colloids is presented, based on the association of several polymeric systems and ferrofluids. On the one hand, we use inorganic nanoparticles made of magnetic iron oxide prepared at the LI2C, which response to a magnetic field of low intensity. On the other hand the organic part is made either of...
0709.3514v1
2007-09-25
The Burst Spectra of EXO 0748-676 during a Long 2003 XMM-Newton Observation
Gravitationally redshifted absorption lines from highly ionized iron have been previously identified in the burst spectra of the neutron star in EXO 0748-676. To repeat this detection we obtained a long, nearly 600 ks observation of the source with XMM-Newton in 2003. The spectral features seen in the burst spectra fro...
0709.4062v1
2007-10-10
The control of iron oxidation state during FeO and olivine crystal growth
Crystal growth experiments (micro-pulling down or Czochralski methods, respectively) and DTA/TG measurements with Fe2+ containing olivines (fayalite--forsterite solid solution) and with FeO (wustite) are performed. For both substances the oxygen partial pressure p_O2 of the growth atmosphere had to be adjusted within t...
0710.2050v1
2007-10-11
RXTE confirmation of the Intermediate Polar status of Swift J0732.5-1331
Aims. We intend to establish the X-ray properties of Swift J0732.5-1331 and therefore confirm its status as an intermediate polar. Method. We analysed 36,240 s of X-ray data from RXTE. Frequency analysis was used to constrain temporal variations and spectral analysis used to characterise the emission and absorption pro...
0710.2248v1
2007-10-23
NGC3147: a "true" Seyfert 2 without the broad-line region
We report on simultaneous optical and X-ray observations of the Seyfert galaxy, NGC3147. The XMM-Newton spectrum shows that the source is unabsorbed in the X-rays ($N_H<5\times10^{20}$ cm$^{-2}$). On the other hand, no broad lines are present in the optical spectrum. The origin of this optical/X-rays misclassification ...
0710.4226v1
2007-10-24
Magnetic tight-binding and the iron-chromium enthalpy anomaly
We describe a self consistent magnetic tight-binding theory based in an expansion of the Hohenberg-Kohn density functional to second order, about a non spin polarised reference density. We show how a first order expansion about a density having a trial input magnetic moment leads to the Stoner--Slater rigid band model....
0710.4399v1
2007-10-25
Ocean Planet or Thick Atmosphere: On the Mass-Radius Relationship for Solid Exoplanets with Massive Atmospheres
The bulk composition of an exoplanet is commonly inferred from its average density. For small planets, however, the average density is not unique within the range of compositions. Variations of a number of important planetary parameters--which are difficult or impossible to constrain from measurements alone--produce pl...
0710.4941v1
2007-10-31
XMM-Newton Detection of a Compton-thick AGN in the 1-Jy ULIRG/LINER F04103-2838
We report on the detection of Fe Kalpha emission in F04103$-$2838, an ultraluminous infrared galaxy (ULIRG; log[L$_{\rm IR}$/L$_\odot$] $\ge$ 12) that is optically classified as a LINER. Previous {\it Chandra} observations suggested the presence of both a starburst and an AGN in this source. A deeper ($\sim$20 ksec) {\...
0711.0002v1
2007-11-01
Magnetic resonance in iron oxide nanoparticles: quantum features and effect of size
In order to better understand the transition from quantum to classical behavior in spin system, electron magnetic resonance (EMR) is studied in suspensions of superparamagnetic magnetite nanoparticles with an average diameter of ~ 9 nm and analyzed in comparison with the results obtained in the maghemite particles of s...
0711.0168v1
2007-11-07
Ultrahigh energy cosmic rays as heavy nuclei from cluster accretion shocks
Large-scale accretion shocks around massive clusters of galaxies, generically expected in hierarchical scenarios of cosmological structure formation, are shown to be potential sources of the observed ultrahigh energy cosmic rays (UHECRs) by accelerating a mixture of heavy nuclei including the iron group elements. Curre...
0711.1027v1
2007-11-12
Low temperature dephasing in irradiated metallic wires
We present phase coherence time measurements in quasi-one-dimensional Ag wires implanted with Ag$^{+}$ ions with an energy of $100 keV$. The measurements have been carried out in the temperature range from $100 mK$ up to $10 K$; this has to be compared with the Kondo temperature of iron in silver, i.e. $T_{K}^{Ag/Fe} \...
0711.1810v2