frequency active ( surtass lfa ) sonar aboard the r / v cory chouest and usns impeccable ( t - agos 23 ) under the national marine fisheries service letters of authorization of 15 august 2007. department of the navy, chief of naval operations, september 2008. [ download ( pdf ) ] this report details the actual operations of the us navy ' s two lfas - equipped ships, from mid - august 2007 to mid - august 2008. both ships remained close to the asian pacific coast, near china, the philippines, and japan. the letter of authorization issued by nmfs, allows the navy to use lfas for up to 432 hours per vessel each year. during this year, the cory chouest used the system for 25 days, totaling 71 hours of transmissions, and the impeccable used it on 24 days for a total of 65 hours of transmissions. during these missions, both passive acoustic detection and an active " whale - finder " high frequency sonar were used to supplement visual marine mammal observers ; no whales were heard via passive listening, one group of whales was spotted visually, and on 19 occasions, whales or turtles were spotted by the whale - finder sonar. operations were suspended 43 times, including the 20 encounters just noted, and 23 times when the whale - finder sonar was not working correctly. such shut - downs occur when whales may move within 1km of the ship ; the whale - finder sonar reliably detects whales out to 2km away. based on current population studies of whales in the region, the report estimates that lfas operations injured no animals, and created possible behavioral reactions ( received levels of 120db or more ) in less than 1 % of most cetacean species, with no more than 3 % of any species affected. the report notes that the lfas source transmitter send out sound in a full 360 degrees, at a source level of 215db or less, using a variety of signal types at 100 - 500hz. the document provides a good overview of the navy ' s eis process since it began in 1996, along with court challenges and rulings from 2002 - 2008. safety thresholds for ocean noise should address character of signal, not just loudness michael stocker. the importance of incorporating signal characteristics in the evaluation of noise exposure impacts on marine life. acoustical society of america presentation, may 2009. this paper is a literature review that presents evidence suggesting that our current reliance on simple amplitude ( db level )


injury ; he proposes evaluation of the following signal characteristics : - rise time of impulse signals - periodicity of intermittent signals - kurtosis, evaluated three ways : fft of spectral distribution, amplitude variability, and spectral variability. measuring air gun propagation from new nsf research ship r / v langseth tolstoy, diebold, doermann, nooner, webb, bohnenstiehl, crone, holmes. broadband calibration of the r / v marcus g. langseth four - string seismic sources. geochemistry geophysics geosysytems, vol. 10, number 8. august 2009. [ download ( pdf ) ] this study marks the primary calibration of the new seismic survey vessel managed by columbia university ' s lamont - doherty earth observatory ( ldeo ) and often chartered by the national science foundation for academic surveys. the langseth ' s air gun arrays are different than those on the previous vessel, the r / v ewing, as it uses four identical 9 - gun linear arrays of somewhat smaller air guns, rather than up to 20 separately towed and larger air guns. tests were run in a deep water site and a shallow water site, since sound propagation varies considerably with depth. sound levels were calculated using both 90 % rms ( re 1upa ) and sel ( re : 1upa2s ). the resulting exposure radii ( safety zones to prevent exposure at the given level ) are as follows : | db threshold rms | db threshold sel interestingly, actual received levels at distances over 3km at the deep site were below the slope of the statistical " line " the data created at closer ranges ; thus the very distant exposure radii are likely over - estimates. as has been widely noted in recent years, sound energy was concentrated in the 10 - 300hz range ( 120 - 150db energy spectral density at 1km ), but continued to have significant energy up to 1khz ( 100 - 120db shallow, 90 - 110db deep ) and 20khz ( 60 - 80db shallow, 20 - 60 esl deep ). of special note in this study is the further clarification that, contrary to previous assumptions, differences between rms and sel are not consistent, but rather vary greatly with water depth. reverberations in shallow environments create a smaller difference ( about 8db ) than in deep water ( about 14db ). fin whales seem to avoid seismic survey castellote, clark, esteban. mediterranean


; the authors note that effects can be sizable at middle frequencies. ( ed. note : for both papers, pre - conference abstracts do not quantify the mid - frequency effects ; details will follow after the presentations and with later publication of results. ) sleep " arousal " and awakening could be cause of wind farm health woes christopher hanning. sleep disturbance and wind turbine noise. june 2009 [ download report ] ( ed. note : this is not a peer - reviewed paper ; it was written for an anti - wind group in swinford, uk. however, dr. hanning, unlike some other physicians wading into industrial wind noise issues, is not writing outside his area of expertise. he ' s a renowned sleep disturbance expert : his school hospital named their sleep lab after him. ) this report by a uk md whose specialty is sleep disorders takes a comprehensive look at factors affecting sleep disturbance caused by nearby wind farms, and is highly recommended reading for anyone working to develop regulations at the local or state level. hanning ’ s primary point is that external noise need not wake a sleeper to cause problems, and the repeated “ arousals ” can break the most restful periods of sleep. he notes that “ the sleep, because it is broken, is unrefreshing, resulting in sleepiness, fatigue, headaches and poor memory and concentration. ” these are precisely the symptoms often reported by people living near wind farms. he stresses that arousals are also associated with “ physiological changes, an increase in heart rate and blood pressure, which are thought to be responsible for the increase in cardiovascular risk. arousals occur naturally during sleep and increase with age ( boselli 1998 ) which may make the elderly more vulnerable to wind turbine noise. arousals may be caused by sound events as low as 32 dba and awakenings with events of 42dba ( muzet and miedema 2005 ), well within the measured noise levels of current wind farms ” and the levels permitted by most jurisdictions. the report also summarizes other studies suggesting that night - time noise levels are often higher than sound models predict, as well as one that suggests that wind farms cause high levels of annoyance at lower sound levels than other common noise sources. he concludes that “ while it may be possible to produce a reasonable acoustically based theoretical approach to calculating set back distances ( kamperman and james 2008b ), it makes more sense to rely on recommendations from observations of the effects on real people at established wind farms. ” some birds choose noisy areas for


a reasonable acoustically based theoretical approach to calculating set back distances ( kamperman and james 2008b ), it makes more sense to rely on recommendations from observations of the effects on real people at established wind farms. ” some birds choose noisy areas for nests francis, c. d., ortega, c. p., and a. cruz. 2009. noise pollution changes avian communities and species interactions. current biology doi : 10. 1016 / j. cub. 2009. 06. 052 a new study surveyed nesting birds in new mexico woodlands with oil and gas compressors, and came up with a surprising result. while, as expected, most birds were more numerous in areas farther from the compressors, two species seemed to prefer these areas. black - chinned hummingbirds and house finches had more than 90 percent of their nests at the noisy sites. the researchers dug a bit deeper, and found that nests in the quiet areas were more likely to be attacked by predators, with predator birds significantly less abundant around noisy sites. it is suggested that the noise may mask their calls or make it harder for them to find their prey. increase in noise levels leads to more annoyance than similar noise in steady state brown, kamp. response to a change in transport noise exposure : competing explanations of change effects. j. acoust. soc. am. 125 ( 2 ), february 2009 this literature review addresses an interesting question, and one that may be relevant to concerns about noise from wind farms. a long history of studies of human annoyance responses to traffic noise seems to suggest that a change in noise levels ( for example, traffic noise increasing from 50db to 60db ) triggers more annoyance than occurs when exposure is steady at the higher level ( in this case, a steady 60db ). this paper reviews many proposed explanations for this affect ; while no single explanation is identified as most likely, several common ones are shown to be unlikely, and a set of plausible explanations remains. among the explanations that are rejected is the common assumption that the annoyance after an increase is transient, and over time will dissipate as people adapt to the new noise level ; in fact, evidence suggests that annoyance remains for years after a change. also of note is that the one study that looked closely at whether attitudes toward a noise source is related to annoyance after an increase in noise found that neither prior attitude nor changes in attitude could account for the increased annoyance. this paper, and its many citations, are highly recommended for anyone addressing community responses to new or increased noise sources


a noise source is related to annoyance after an increase in noise found that neither prior attitude nor changes in attitude could account for the increased annoyance. this paper, and its many citations, are highly recommended for anyone addressing community responses to new or increased noise sources. harbor porpoise tts, behavioral response at moderate noise levels in lab tests lucke, seibert, lepper, blanchet. temporary shift in masked hearing thresholds in a harbor porpoise ( phocoena phocoena ) after exposure to seismic airgun stimuli. j. acoust. soc. am. 125 ( 6 ), june 2009. field researchers have observed for years that harbor porpoises appear more sensitive to noise than most other cetacean species, moving away from noise sources at greater distances than typically considered problematic ( belugas and bowhead whale mothers are also more behaviorally sensitive to noise ). this study was the first that measured harbor porpoise auditory sensitivity in the lab, using auditory evoked potential measurements ( brain - wave scanners that note auditory brain activity ), and the results confirm that this species ' avoidance behavior occurs at relatively low sound levels, and may be linked to a similarly low threshold of tts ( temporary hearing loss ). the test animal was a wild - born ten - year old porpoise who has lived in captivity in denmark for most of his life ; the testing facility is open to the sea, so background noise ( ranging roughly from 60 - 80db pressure spectral density ) is dominated by local shipping sounds. a single small ( 20 cubic inches ) airgun was used as the sound source, gradually moving closer until a tts was observed at one of the 3 tested hearing frequencies ( 4, 32, and 100khz ). the airgun source sound was, as is typical, loudest at low frequencies ( max of 150db spl at 300hz ), but had significant energy at higher frequencies as well ( 100 - 110db spl from 2khz to 5khz ), at the relatively close range used in this test ( 14 - 150m ). the key finding was that the airgun sounds caused tts in the 4khz hearing range at received levels of 165. 5db sel ( 202. 1db peak to peak ) ; perhaps more importantly, recovery was quite slow, with reduced sensitivity ( i. e., sound had to be louder than normal to be heard ) still measured at 29 hours post - exposure. based on the pattern of recovery


tts ; temporary decline in hearing sensitivity ) after exposure to loud noise in dolphins, calls into question one of the key advantages of the sound exposure level metric. sel measurements are designed to measure total sound exposure over a given period of time ; simply stated, sel remains constant when sound intensity increases while duration decreases ( e. g., twice as loud for half as long should result in " equal energy ", or the same sel ). the assumption was that sel offered an " equal energy " metric that could allow biologists and ocean regulators to set a sel threshold that would apply to many types of noise exposure. however, this study indicates that a given sel db level ( arrived at via a mathematical equation combining sound energy from many noise pulses over time ) did not seem to induce tts in the single captive dolphin used in this study. as with other metrics, higher sels were required to induce tts with shorter duration sounds. by extension, the hypothesis that tts is caused by a given level of sound energy ( the " equal energy " hypothesis ) is called into question. the relationship appears to be logarithmic, rather than linear. in this study, the sound source was short ( 20ms ) digitally generated tone bursts. related : mid - frequency sonar must be very loud / close to trigger tts mooney, nachtigall, vlachos. sonar - induced temporary hearing loss in dolphins. biology letters, doi : 10. 1098 / rsbl. 2009. 0099 the same team more recently found the same difficulty with using sel to predict tts when using a recording of a us naval mid - frequency active sonar ; short duration mfa " pings " had to be ramped up to a sel of 214db ( equivalent to 203db spl rms ) to induce a modest tts of 6db, which faded rapidly back to normal hearing levels in 20 - 40 minutes, a higher sel than had induced tts using longer duration sounds in the above study. this was the first hearing test on dolphins to use actual mid - frequency active sonar signals ; previous studies had used sonar simulations or tones at similar frequencies. ed. note : the usual caveats are in order here, as a long - time captive dolphin may not hear as well as his wild relatives ; it is often assumed that captive dolphins are less sensitive both physiologically ( hearing loss from living in noisy pens ) and behaviorally ( habituated to noise, and given food to remain in the


captive dolphin may not hear as well as his wild relatives ; it is often assumed that captive dolphins are less sensitive both physiologically ( hearing loss from living in noisy pens ) and behaviorally ( habituated to noise, and given food to remain in the test area ), though the relative lack of clear studies on wild animals makes this assumption difficult to confirm. wind turbines do not seem to displace wintering farmland birds devereaux, denny, whittingham. minimal effects of wind turbines on the distribution of wintering farmland birds. journal of applied ecology 2008, 45, 1689 - 1694. in what be the first study examining whether wind farms displace birds, this team studied bird distributions around two small wind farms in england ( each had 8 2mw 60m hub - height turbines in two rows ). birds of four different functional groups ( seed - eaters, corvids, gamebirds, and skylarks ) were counted at five distances ( multiples of 150m, out to 750m ). after controlling for crop types and boundary effects, there was no overall significant difference in distribution by distance. one species was an exception to the overall findings : the largest and least maneuverable bird, the common pheasant, was more common as distance increased. two other species not included in the overall study of functional groups were also less abundant within 150m : the mallard and the wood pigeon, also both less maneuverable than most of the other birds in the area ( the authors note that counts were low enough for these that the pattern may have been skewed by a few large flocks ). in some cases ( skylarks and corvids ), the data showed statistically significant increases in bird numbers closer to the turbines. the authors make a point of noting that this winter study needs to be complemented by similar investigations of distribution during the breeding season, when birds may be affected differently. this study did not study noise, but just the presence of the turbines. related : compressor station noise can reduce forest bird abundance bayne, habib, boutin. impacts of chronic anthropogenic noise form energy - sector activity on abundance of songbirds in the boreal forest. conservation biology, volume 22, no. 5, 1186 - 1193, 2008. this study used an innovative study design to separate the effect of noise from the also - important effects of habitat disruption and edge effects caused by energy development. the authors compared bird distributions around ( quiet ) well pads and ( constantly noise


1193, 2008. this study used an innovative study design to separate the effect of noise from the also - important effects of habitat disruption and edge effects caused by energy development. the authors compared bird distributions around ( quiet ) well pads and ( constantly noise - producing ) coalbed methane compressor stations in the forest of alberta. they found that areas near well pads had a passerine density of 1. 5 times higher than areas near compressor stations ; one - third of the species studied showed this affect. the noise levels produced by the compressor stations is typically 75 - 95 db ( a ) at the source, sometimes reaching 105db ( a ) at large facilities ; compressor noise is commonly heard at distances of well over 1km in the boreal forest ; with 5000 compressor stations in boreal alberta, the question of noise - related displacement is potentially significant. in addition to the overall tendency for passerines to be found in greater numbers near quiet energy installations than noisy ones ( with three species especially affected ), seven other species showed less dramatic but still noticeable differences, while eleven other species showed no difference. red - eyed vireos, white - throated sparrows, and yellow - rumped warblers were particularly affected, with chickadees, jays, and wrens showing little effect. right whales experience dramatic variations in noise during annual movements along north american coast parks, urazghildiiev, clark. variability in ambient noise levels and call parameters of north atlantic right whales in three habitat areas. j. acous. soc. am. 125 ( 2 ), february 2009. this study used pop - up recorders to examine ambient noise conditions and right whale calls in three of the species ' annual habitats : the bay of fundy, cape cod bay, and the coast of georgia. while the variability of calls was subtle, there was some indication that louder call patterns were in response to the peak sound in an area, rather than the overall noise level. however, the seasonal variability of noise experienced by this population is the key finding here. overall sound levels were highest during the summer season spent in the bay of fundy, and lowest in the winter off georgia. likewise, the percentage of time that the habitat was " loud " ( ambient noise over 105db re 1upa in the 50 - 350hz frequency range of right whale contact calls ) varied dramatically : in the bay of fundy, it was loud 85 - 95 % of the time, in cape cod bay it was loud 53 - 63 % of the time, and


resident killer whales orcinus orca. endangered species research, vol. 6 : 199 - 209, 2009. this companion paper by the same research team does not address foraging, but rather looks at overall behavioral effects of the same boat traffic measured in the above study. they find that behavioral changes such as swimming speed and directness of travel path changed slightly in response to boats, and in general, they found that changes were more correlated to the number of boats within 400 yards than by the proximity of the boats, whereas current whale watching standards address only how close each boat is, rather than total numbers of boats. they also note that, given the difficulties in finding clear patterns within this noisy environment, it may be hard for managers to feel that the data is solid enough to warrant additional protections. however, the authors conclude with the observation that it appears that this population is food - limited ( many researchers consider declining salmon runs to be a primary factor in population stagnation and sometimes dips ), and suggest that reducing the ambient noise levels would improve the whales ' ability to find the limited food that remains in the region. ed. note : this paper ' s focus on numbers of vessels corresponds well with the holt paper directly above, which finds overall ambient noise is closely tied to the number of boats in the vicinity. soundscapes, acoustic daylight, and fish hearing richard fay. soundscapes and the sense of hearing in fishes. integrative zoology 2009 ; 4 : 26 - 32. this fascinating review offers a wide - ranging consideration of the implications of a simple observation : goldfish have an acute sense of hearing, though they do not vocalize or engage in any known sound communication. what are they listening to? fay introduces several key lines of research into fish hearing, some dating from the 80s, and some from the past decade. his own research, along with that of several others, has demonstrated that fish can isolate multiple sound sources ( though studies cited are limited to two distinct sounds, rather than much more complex mixes of sound ). from there, fay suggests that fishes ' sensitivity to particle motion in water, via their lateral lines, provides them the ability to engage in what in human perception is termed " auditory scene analysis, " or the perception of a complex environment by distinguishing the many sound sources and their motion through the soundscape. the most intriguing suggestion in the paper is less solidly fleshed out : that fish make use of reflections of ambient sound to build this " auditory scene. " that is, ambient noise can act as "


sources and their motion through the soundscape. the most intriguing suggestion in the paper is less solidly fleshed out : that fish make use of reflections of ambient sound to build this " auditory scene. " that is, ambient noise can act as " acoustic daylight, " with subtle differences in the echoes of the overall ambient sound bouncing off specific objects being a source of perception ( as light reflects off objects to create visual perception ). fay mentions one study in which goldfish were shown to be able to perceive a single point source of delayed ( as if echoed ) signal in a noise field ; this was apparently done with artificial noise sources, though the researchers ( and fay ) propose that it represents an ability of goldfish to perceive the fish bladder of another fish re - radiating ambient noise. this may well be true, though this ( and one other related study that showed fish using echoes from self - produced sound ) do not yet cross the chasm of showing that fish process complex acoustic scenes by using reflections of ambient noise. yet the point of this review is not to " make a case " for these higher order perceptual abilities, but rather to open our minds to the likely fact that fish listen to much more than simply communication signals, which have been overlooked due to our " profound ignorance of the other possible sounds and sources that probably have biological significance to fish, " and to suggest that " environmental soundscapes ( are ) most probably important sources of information. " this more modest first step is clearly successful here, opening the way to future studies of the undoubtedly subtle and complex sensory world of fishes. iucn report highlights noise impact of shipping in mediterranean, calls for mpas to provide " acoustic comfort " ameer abdulla, olof london ( editors ). 2008. maritime traffic effects on biodiversity in the mediterranean sea : review of impacts, priority areas and mitigation measures. malaga, spain : iucn centre for mediterranean cooperation. 184 pp. [ download ( pdf ) ] [ website ] this comprehensive look at mediterranean shipping, from the international union for the conservation of nature and natural resources, includes a long section in the early pages on noise impacts. due to the concentration of shipping in the mediterranean, ambient noise is 40db higher than in relatively shipping - free seas such as the sea of cortez. among the recommendations made in regards to noise are that " much effort should be devoted to developing a legal framework within which underwater noise is recognized and regulated as a threat, " and the advocacy of mpas that are designed to provide acoustic protection to


only made in quite calm seas ( beaufort 2 or lower ). a large local population of dolphins offered plenty of data, and the population is generally stable in place, engaging in a series of regular behaviors over relatively prolonged timeframes. behavior " without " boats present was noted when no boats ( other than the observation inflatable ) were within 350m ; behavior " with " boats present was noted when tour boats came within 150m. ( ed. note : it would be interesting to consider the data when tour boats were 150 - 350m distant, to assess whether the observed effects extend to greater distances ). over the course of 65 hours of observation by a single observer, 1028 3 - minute behavioral samples were taken, 781 with no boat ( average duration 69 min. ), and 247 with a tour boat present ( average duration 47 min. ). as usual with such studies, several behavioral states were analyzed : traveling, socializing, resting, milling, feeding, and diving. all showed some change in the presence of boats, with traveling, milling, and diving all increasing in the presence of boats, and socializing, feeding, and resting decreasing. of these, the most relevant to an animal ' s energy budget all were negatively affected : traveling increased from 27 % of the time to 46 %, resting decreased from 31 % to 20 %, and by far the largest energetic impact was seen in feeding, which reduced from 20 % of the time to just 7. 6 % of the time. this is the most dramatic decrease in feeding seen in such studies ( others have tended to find a 25 - 35 % decrease in foraging ). this may indicate that the relatively localized population had plenty of time to eat when the boats were not present, and chose to either leave or play with the boats when they were present. the study did look at attraction / deterrence, finding that in in 20 % of cases, dolphins moved closer to the boats, while in 28 % of encounters, they moved away ( about half the time, there was no spatial difference, though behaviors may still have changed ). the discussion section of this paper includes an unusually detailed comparison of the findings and the contexts of this and several similar studies, as well as consideration of the ways that in other settings, were human activity is more prevalent, these behavioral changes could have longer - term, population - level impacts. excellent review of the effects of human - generated sound on fish popper and hastings. the effects of human - generated sound on fish. integrative zoology


passive acoustic detection of beaked whales : easy within 1km, nearly impossible beyond 4km zimmer, harwood, tyack, johnson, madsen. passive acoustic detection of deep - diving beaked whales. the journal of the acoustical society of america, november 2008, volume 124, issue 5, pp. 2823 - 2832. beaked whales spend very little time at the surface, with foraging dives that last an hour or more, including about 30 minutes of active echolocation at the feeding depth. visual detection is very difficult, so the possibility of using passive acoustic detection ( pad ) is an attractive complement to visual spotting. however, these high - frequency clicks attenuate rapidly. according to this paper, acoustic modeling suggests that in " good conditions, " e. g. wind speed of 2 m / s, a hydrophone close to the surface should detect beaked whales with a high probability within. 7km. at the other end of the detection range, no whales would be detected at distances greater than 4km, except in very low ambient noise or unusually good propagation conditions. the detection curve generated by the models, drops steeply as distance increases, with a relative leveling off that suggest roughly 50 % detection when whales are 1. 5 - 3. 5km distant. additionally, the researchers substituted some actual dive profile data obtained in d - tag studies, and found that in these instances, detection probability may rise somewhat, with 80 % detection being possible at distances of 1. 5 - 2. 5 km. actual detection of real whales is complicated by the fact that the sound of the clicks is highly directional ; only clicks directed nearly directly toward the receiver will be heard at the modeled distances, but echolocating whales do scan in many directions, so at least some clicks from any whale should be detected. finally, the relatively quiet interval between deep foraging dives can be as long as 110 minutes, meaning that listening time should be roughly 140 minutes to have a high probability of detecting if beaked whales are present. this, in turn, suggests that a slow - moving vessel ( such as gliders or drifting buoys ) will be more successful than a fast - moving active sonar vessel. ( that is, if detections are only going to occur within roughly 4km, the listening platform should not move out of a relatively similar area during the 2 - hour - plus pad session. ) ed. note : while it has still not been confirmed to all observers ' satisfaction, there is some evidence that beak


roughly 4km, the listening platform should not move out of a relatively similar area during the 2 - hour - plus pad session. ) ed. note : while it has still not been confirmed to all observers ' satisfaction, there is some evidence that beaked whales affected by mid - frequency active sonar may well have been tens of km from sonar vessels. thus, pad may be useful for avoiding nearby exposure, but may not fully mitigate for effects that could occur at greater distances, including fleeing in ways that disrupt the whales ' post - dive recovery and oxygen / nitrogen rebalancing. detailed review of sound exposure impacts on puget sound orcas released by noaa marla holt, sound exposure and southern resident killer whales ( orcinus orca ) : a review of current knowledge and data gaps. noaa technical memorandum nmfs - nwfsc - 89, february 2008. 77pp. [ download report ( pdf ) ] this review includes summaries of most of the studies of ambient and shipping noise in the range of the southern resident orca pods of the pacific northwest. topics covered include ambient sound patterns, shipping noise, whale watching noise, orca auditory capabilities and auditory effects of sound exposure, including masking and hearing loss, and behavioral changes in the presence of excess sound. an important section looks at the emerging concept of " zones of influence " of sound : the zones of audibility, response, masking, and hearing loss or injury. the report concludes with a section that assesses the likelihood of acoustic impacts and suggestions for future research. the report is a treasure - trove of clear information on noise / sound impacts. among the points that stood out in my reading are the following. ambient noise is generally elevated at least 10 - 15db by small boats, and 20 - 25db by large ships ( another study indicates increases more in the range of 50 - 70db in the presence of various boats ). the section on hearing sensitivity makes a point about captive animal testing that is rarely noted : when animals receive negative reinforcement for reporting a " false positive " ( i. e. responding as if hearing a sound, when no sound was played ), they may well become conditioned to be conservative in their response to faint sounds, and so the results can easily underestimate the hearing sensitivity of the species ( for orcas, only two studies have been done on captive whales to assess hearing sensitivity curves ). tentative measurements of the critical ratios for orcas ( tentative because, again, there are few test subjects ) suggest that they


, miller, doksaeter, knudsen, tyack, nordlund, lam, samarra, kleivane, godo. herring ( slid ), killer whales ( spekknogger ) and sonar - the 3s - 2006 cruise report with preliminary results. norwegian defence research establishment ( ffi ). 30 april 2007 this paper reports preliminary results from an ambitious multi - national controlled exposure experiment using acoustic d - tags, which allow researchers to record received sound levels while charting dive patterns. six orcas were tagged, with 17 hours of data collected, with one animal exposed to lfas signals, two to mid - frequency active sonar signals, and one used as a control, fewer samples than hoped. the whale exposed to lfas signal did not change its behavior, nor did its companions. however, the group exposed to mid - frequency sonar signals ceased feeding and moved rapidly away ; in addition, they exhibited an unusual dive pattern, diving roughly twice as deep ( over 60m ) as normal ( 20 - 45m ), including a highly unusual reversal of their ascent ( coming up to 15m from the surface, then retreating again to 60m ). [ ed. note, not part of the report narrative, based on observation of included diagrams : four other dives during the 35 - minute sonar transmission were within the normal range of depth ( the deep dive was the third of five dives during sonar transmission ), with three longer than normal rest periods at the surface during the hour after sonar transmission ceased. ] received levels did not exceed 150db re 1upa. looking at longer - term responses, while the experimental use of sonar in the herring trials did not seem to deter orcas from the general area, by contrast, no orcas were seen during three days of a planned navy exercise in the area that included mid - frequency sonar use. the herring trials used bottom - mounted sensors to chart the mean depth of a school of herring as a sonar vessels passed nearby. herring at shallow depths ( 25 - 50m ) tended to show a minor downward reaction as the sonar source ship passed overhead, while herring located deeper, or in less dense schools, showed no detectable reaction ; no horizontal avoidance was seen. while herring hearing curves suggest they should be able to clearly hear lfas signals, but not mid - frequency signals, the responses were the same for all signals ( including ship - only, no sonar ), suggesting that the herring may have been responding to the sound of the ship, rather


killer whales staying 4km away from acoustic harassment signals near fish farms, dolphin numbers dropping to 8 % of normal within 3. 5 km of similar noise - makers on other fish farms ( with those small numbers implying that the avoidance distance was far greater ). he notes that the degree of displacement or behavioral response is not necessarily a direct indicator of the severity of impact, suggesting that " if an animal is in bad enough condition that the risk of altering behavior is high, then it may be less likely to show a disturbance response. " for example, hungry animals will linger in a feeding area the longest. he also notes that some responses to noise may be caused by noise sources that resemble a predator ' s call ( as in recent modeling tyack has done that suggests beaked whale decompression sickness may result from a long series of near - surface dives as the whales flee sonar signals that they mistake for orca calls ). he cites some compelling studies on terrestrial animals showing that repeated disturbance exacts high costs in reproductive success and overall health ( including a study of geese that showed that when undisturbed, geese increased their body mass and had a 46 % breeding success, whereas in nearby areas where farmers scared them off their fields, they did not gain mass and had a breeding success of only 17 % ). to conclude, tyack suggests that there are several lines of research that have so far received little attention, which could help to move key understanding of noise impacts forward, including : focusing on the most vulnerable animals as subject of study into the effects of disturbance, further study of the possibility that predator responses underlay key behavioral impacts ( including fleeing, increased vigilance, and avoiding habitats ), and following up on the recent theory of allostasis ( behavioral changes that allow an animal to maintain equilibrium in the face of external environmental changes or stressors ) as a way of understanding the costs and benefits of changing behavior in the face of noise. workshop report : encouraging establishment of noise - free zones in and around marine protected areas agardy, aguilar, canadas, engel, frantzis, hatch, hoyt, kashner, labrecque, martin, notarbartolo di sciara, pavan, servidio, smith, want, weilgart, wintle, wright. 2007. a global scientific workshop on spatio - temporal management of noise. report of the scientific workshop. 44 pages. [ download ( pdf ) ] in june 2007, a workshop was held in the canary


weilgart, wintle, wright. 2007. a global scientific workshop on spatio - temporal management of noise. report of the scientific workshop. 44 pages. [ download ( pdf ) ] in june 2007, a workshop was held in the canary islands to consider the potentials for extending the management principles used in marine protected areas to provide some protection from anthropogenic noise. fundamental to the purpose and effectiveness of mpas are " spatio - temporal restrictions " ( strs ) of specific human activities : for example, excluding fishing, from a specific area ( spatial restriction ), or sometimes at times of special biological importance, such as spawning ( temporal restriction ). few of today ' s mpas are large enough to provide protection from " elevated levels of ensonification : " buffers of tens of kilometers would be necessary for protection from mid - frequency sound, and a hundred or more kilometers from low - frequency sound. of today ' s 350 mpas that include some cetacean habitat, 64 are large enough to provide some mid - frequency protection, 20 are large enough to provide at least some low - frequency protection ( e. g. shipping ), and only the 6 largest are probably sufficient to protect from shipping noise. ( of course, shipping is not generally excluded from mpas : this is merely a hint at the scale of noise strs that would be useful. ) the workshop report includes several key sections : - descriptions of some existing attempts to provide strs focused on noise : in 2003, brazil established a large buffer zone around a small existing mpa, to exclude the sounds of seismic survey airguns from entering the mpa ( the buffer was withdrawn by a court due to jurisdictional issues ; attempts are underway to re - establish it ). in the canary islands, a 50 nautical mile buffer zone has been established around the islands, in which active sonar is not allowed ( there have been some subsequent strandings that raise questions whether this is large enough a buffer ). - recommendations for mpa managers, centered on a framework for making management decisions regarding possible noise - related strs. - recommendation that noise - producers provide more information, and longer lead times prior to operations near mpas, to allow for analysis of effects of proposed noise. a far - reaching element of this is a call for use of " detectability curves " to reflect how easy it is to find various species of whales, and to insure that more effort is made to find hard - to - detect whales, rather than assuming that they are


of this is a call for use of " detectability curves " to reflect how easy it is to find various species of whales, and to insure that more effort is made to find hard - to - detect whales, rather than assuming that they are not present if none are found using standard observational techniques. - recommended measures that could reduce the noise impacts of the primary noise producing activities. - suggested mpas or proposed mpas where noise - oriented strs could be introduced, as case studies for future mpa management protocols. these include the pelagos sanctuary in the northwestern mediterranean, off france, italy, and monaco, the alborian sea / strait of gibraltar, the bay of bengal, and east asian waters off japan, china, and the philippines. ocean fish vary widely in startle response to noise kastelein, van der heul, verboom, jennings, van der veen, de haan. startle response of captive north sea fish species to underwater tones between 0. 1 and 64khz. marine environmental research 65 ( 2008 ) 369 - 377. this study exposed eight marine fish species to pure tones ranging from 100hz to 64khz. the tests took place in specially designed quiet tanks ; species were chosen in part due to their economic importance to fisheries. some species did not respond to the sound at all, even at the highest db levels that could be produced, while others exhibited very clear startle responses to a relatively narrow range of frequencies ( generally 100 - 700hz ), at received levels of about 100db ( re 1upa, rms ) for the lowest frequencies, with the startle threshold increasing to the range of 160db as frequency increased to 700hz. only one species responded to higher frequencies than this : horse mackerel responses extended up to 2khz. the species that did not startle at all were atlantic cod, pollack, common eel, and atlantic herring. horse mackerel startled to the widest range of frequencies, with sea bass also quite responsive ; thicklip mullet and pout both startled to a narrower range of frequencies. interestingly, for fish that have established audiograms, it appears that the startle response does not begin until the noise is 10 - 30db above the hearing threshold ; and, again, some fish showed no startle even at levels up to 45db above their presumed hearing threshold. the researchers note that these results on captive fish to pure tones can not be reliably extrapolated to wild


in situ measurement and equalization of sound reproduction systems the concept of frequency response is of basic importance to audio reproduction equipment. when analyzing electronic equipment, this characteristic is seldom a problem of measurement or interpretation. it is a problem, however, for acoustical transducers such as loudspeakers. unlike electronic equipment which has both electrical input and output terminals, the loudspeaker has an electrical input terminal but an acoustical output. this acoustical output is further complicated by the fact that a room is always interposed between the loudspeaker and the acoustical measuring device. with the human as the ultimate evaluation instrument, various measurement and interpretation questions arise regarding frequency response, variations among listeners, and effect of program material. the major question, however, is just what the frequency response of a particular sound reproduction system should be. in order to answer these questions, several psychoacoustical experiments were devised, based upon a listener ' s ability to detect differences. these experiments and their results are described in detail as they relate to the following types of sound reproduction systems : 1 ) sound reinforcement systems, 2 ) studio monitoring systems, 3 ) home high - fidelity systems. click to purchase paper or login as an aes member. if your company or school subscribes to the e - library then switch to the institutional version. if you are not an aes member and would like to subscribe to the e - library then join the aes! this paper costs $ 20 for non - members, $ 5 for aes members and is free for e - library subscribers.


smart phones are changing real world privacy settings thursday, may 10, 2012 tau research finds that smart phone users develop new concepts of privacy in public spaces with endless applications, high - speed wireless internet access, and free messaging services, smart phones have revolutionized the way we communicate. but at what cost? according to researchers at tel aviv university, the smart phone is challenging traditional conceptions of privacy, especially in the public sphere. dr. tali hatuka of tau ' s department of geography and dr. eran toch of tau ' s department of industrial engineering have teamed to measure the impact of the smart phone phenomenon on privacy, behavioral codes, and the use of public space. their early results indicate that although spaces such as city squares, parks, or transportation were once seen as public meeting points, smart phone users are more and more caught up in their technology - based communications devices than their immediate surroundings. smart phone users are 70 percent more likely than regular cellphone users to believe that their phones afford them a great deal of privacy, says dr. toch, who specializes in privacy and information systems. these users are more willing to reveal private issues in public spaces. they are also less concerned about bothering individuals who share those spaces, he says. inside a private bubble dr. hatuka says that smart phones create the illusion of " private bubbles " around their users in public spaces. she also believes that the design of public spaces may need to change in response to this technology, not unlike the ways in which some public areas have been designated as " smoking " and " non - smoking. " dr. toch also notes that smartphones and personal computing devices are becoming more " context - aware, " adjusting themselves in terms of brightness and volume to the user ' s location and activity. to examine how smart phones have impacted human interactions in public and private spaces, the researchers designed an in - depth survey. nearly 150 participants, half smart phone users and half regular phone users, were questioned about how telephone use applied to their homes, public spaces, learning spaces, and transportation spaces. while regular phone users continued to adhere to established social protocol in terms of phone use — postponing private conversations for private spaces and considering the appropriateness of cell phone use in public spaces — smart phone users adapted different social behaviors for public spaces. they were 50 percent less likely to be bothered by others using their phones in public spaces, and 20 percent less likely than regular phone users to believe that their private phone conversations were irritating to those around them, the researchers found.


behaviors for public spaces. they were 50 percent less likely to be bothered by others using their phones in public spaces, and 20 percent less likely than regular phone users to believe that their private phone conversations were irritating to those around them, the researchers found. feeling lost without a phone according to the researchers, smart phone users were also more closely " attached " to their mobile devices. when asked how they felt when they were without their phones, the majority of smart phone owners chose negative descriptors such as " lost, " " tense, " or " not updated. " regular phone users were far more likely to have positive associations to being without their phones, such as feeling free or quiet. the next phase of the study will be a more in - depth analysis of how smart phone users incorporate this technology into their daily lives. it requires users to install an application that the researchers developed called smart spaces. the application is designed to track where the participants go over a three - week period and how they use their phones while there. this will give researchers a better idea of how smart phone users interact in both public and private spaces during the course of a typical day. dr. hatuka and dr. toch believe that their complete findings can reveal clues about the future of public space and how it will be designed in order to meet the needs of those it serves. " we are entering a new phase of public and private spaces, " says dr. hatuka, suggesting that physical spaces need to be redesigned as arenas which could enhance personal interaction. for more technology news from tel aviv university, click here.


science fair project encyclopedia pressure cooking is a method of cooking in a sealed vessel that does not permit air or liquids to escape below a preset pressure. because water ' s boiling point increases as the pressure increases, the pressure built up inside the cooker allows the liquid in the pot to rise to a temperature higher than 100 °c ( 212 °f ) before boiling. the higher temperature causes the food to cook faster. cooking times can be reduced by a factor of three or four. for example, shredded cabbage is cooked in one minute, fresh green beans take about five, small to medium - sized potatoes ( up to 200 g ) may be ready in five minutes or so and a whole chicken takes no more than twenty - five minutes. it is often used to simulate the effects of long braising or simmering in shorter periods of time. a safety valve releases steam when the pressure exceeds the safety limit for the cooker ; usually the steam pressure lifts a weighted stopper allowing excess pressure to escape. there is usually a backup pressure release mechanism, in the form of a hole in the lid blocked by a plug of low melting - point alloy. if internal temperature ( and hence pressure ) gets too high, the metal plug will melt, resulting in a release of the pressure. a pressure cooker is often used by mountain climbers to compensate for the low atmospheric pressure at high altitude. without it, water boils off before reaching 100 °c, leaving the food improperly cooked, as described in charles darwin ' s voyage of the beagle : at the place where we slept water necessarily boiled, from the diminished pressure of the atmosphere, at a lower temperature than it does in a less lofty country ; the case being the converse of that of a papin ' s digester. hence the potatoes, after remaining for some hours in the boiling water, were nearly as hard as ever. the pot was left on the fire all night, and next morning it was boiled again, but yet the potatoes were not cooked. i found out this, by overhearing my two companions discussing the cause, they had come to the simple conclusion, " that the cursed pot [ which was a new one ] did not choose to boil potatoes. " a larger scale version of a pressure cooker, used by laboratories and hospitals to sterilise biological waste materials, surgical instruments etc. is known as an autoclave. the contents of this article is licensed from www. wikipedia. org under the gnu free documentation license. click here to see the transparent copy and copyright details


backward and forward both run to need may they, faster run to are computers if a turing machine is fine for reasoning about computers, but it ' s not an ideal model for building them. some more practical components of reversible logic were introduced in the 1980s by edward f. fredkin and tommaso toffoli, who were then working together at mit. ( fredkin is now at carnegie mellon university, toffoli at boston university. ) the components are logic gates, somewhat like and and or gates but designed for reversibility. in any reversible gate the number of inputs must equal the number of outputs. moreover, each possible set of inputs must yield a distinct set of outputs. if this were not the case — that is, if two or more input patterns had the same output — then the reverse action of the gate would be ambiguous. the devices now known as the fredkin gate and the toffoli gate ( see illustration on page 109 ) both have three inputs and three outputs ; and, as required for reversibility, each input pattern maps to a unique output. in the fredkin gate, one signal controls whether the other two data lines pass straight through the gate or else have their positions swapped. in the toffoli gate, two of the signals control the third ; if the first two bits are both 1, then the third bit is inverted. like the not gate, both the fredkin and the toffoli gates are their own inverses : no matter what the values of the three input signals, running them through two successive copies of the same gate will return the signals to their original values. both gates are also computationally universal, meaning that a computer assembled from multiple fredkin or toffoli gates ( and no other components ) could simulate a turing machine or any other device of equivalent computational power. thus the gates might be considered candidates for a real reversible computer. of course logic gates are still just abstract devices ; they have to be given some physical implementation with transistors or other kinds of hardware. starting in the early 1990s, several groups have been designing and building prototypes of reversible ( or nearly reversible ) digital circuits. for example, at mit a group including michael frank and thomas f. knight, jr., fabricated a series of small but complete processor chips based on a reversible technology ; frank continues this work at florida state university. at the university of gent in belgium, alexis de vos and his colleagues have built several reversible


., fabricated a series of small but complete processor chips based on a reversible technology ; frank continues this work at florida state university. at the university of gent in belgium, alexis de vos and his colleagues have built several reversible adders and other circuits. it ' s important to note that building a computer according to a reversible logic diagram does not guarantee low - power operation. reversibility removes the thermodynamic floor at kt ln 2, but the circuit must still be designed to attain that level of energy savings. the current state of the art is far above the theoretical floor ; even the most efficient chips, reversible or not, dissipate somewhere between 10, 000 and 10 million times kt ln 2 for each logical operation. thus it will be some years before reversible technology can be put to the ultimate test of challenging the three - zeptojoule barrier. in the meantime, however, it turns out that some concepts derived from reversible logic are already useful in low - power circuits. one of these is charge recovery, which attempts to recycle packets of electric charge rather than let them drain to ground. another is adiabatic switching, which avoids wasteful current surges by closing switches only after voltages have had a chance to equalize. » post comment


shallow water surface drifters in response to noaa / cop funded research needs for high resolution lagrangian analysis of florida bay interior basin flow fields, a shallow water drift buoy was designed and developed by aoml and rsmas in miami, florida. primary design guidelines required a device capable of operating in water depths of one meter or less for up to a two week period. small size was a factor both in minimizing windage at the surface and in aiding deployment and recovery efforts. the drifter would also require onboard gps for accurate positioning. the need for a high - resolution record of the driftera€™s track required gps data to be logged onboard for post - recovery upload. however, in attempts to aid users in the driftera€™s recovery, a subset of these data would need to be transmitted to the users during deployment ; this is handled by an onboard argos transmitter. the hull is constructed of a 0. 125 inch thick lexan, two - piece thermoformed shell in the general shape of a disc. the top is slightly domed and the bottom has molded fins in an attempt to couple the buoy to the water. unfortunately, in the first bay drift test the molded fins proved to be insufficient to keep windage to a minimum, so a " window shade " drogue has been incorporated with excellent results to improve coupling to the water ( see figure ). the drogue is constructed of two crossed, flexible pvc sheets and is approximately 0. 75 meters long. the shape of the buoy was analyzed to insure that it would be self - righting if turned over by a wave. when deployed, the hull floats with the top of the dome approximately 3 cm above the waterline. the dimensions of the hull are 33 cm in diameter by 15 cm high and the weight ready for deployment is less than 5 kg. to derive high - resolution currents, the position of the buoy must be determined frequently. a motorola 12 channel gps receiver is built into the electronics to collect this data. it computes 3 dimensional position information at pre - selected rates which are then stored in the buoy memory for later retrieval and subsequent data analysis. a relocation argos satellite transmitter system is included in the electronics to recover the buoy at the end of each experiment. the argos positions are used to get within the general vicinity of the buoy, and then a handheld argos receiver on the boat is used to locate and retrieve the buoy.


submitted to : veterinary parasitology publication type : peer reviewed journal publication acceptance date : october 1, 2000 publication date : n / a interpretive summary : sarcocystis neurona is a single - celled parasite of companion animals. it causes a fatal neurologic syndrome in horses in the u. s., called eqine protozoal myeloencephalitis ( epm ). its full life cycle is not known. opossums are its reservoir ( definitive ) host and horses are considered aberrant hosts. scientists at the beltsville agricultural research center and the montana state university describe the ultrastructure of sarcocysti neurona stages ( schizonts ) found in tissues of horses. these results will be of interest to biologists and parasitologists. the ultrastructure events associated with nuclear division were studied in schizonts of sarcocystis neurona. merozoites developed by type 2 endopolygeny in which numerous merozoites began development internally and later budded at the schizont surface. the nuclear envelope remained intact during all nuclear divisions. the schizont nucleus enlarged to form numerous lobes, each of which contained an intranuclear spindle. many spindles were formed before merozoite formation. spindles were conical - shaped with the apex of the spindle located immediately beneath a pore in the nuclear envelope. most spindle microtubles were discontinous, terminating at kinetochores on chromosomes, whereas a few microtubules were continuous extending between each pole of the nuclear spindle. two centrioles, a golgi complex and a plastid were closely associated with each pole of the nuclear spindle. spindle microtubules shortened during spindle edivisions that occurred in early and intermediate schizonts prior to the formation of merozoite primoridia. the length of the spindle microtubules remained the same during the last spindle during merozoite formation. separation of the chromosomes appeared to result from enlongation of each nuclear lobe which occurred simultaneously with elongation of the inner membrane complex and subpellicular microtubules surrounding the merozoite primordia. in schizonts, the plastid was disc - shaped, variable in size, and consisted of a granular core with ribosomes and small vesicles surrounded by 2 - 4 membranes. plastids in


trees of life a visual history of evolution written by theodore w pietsch john hopkins university | isbn 9781421404790 hardback – 376 pages member ’ s price : $ 82. 80 usually ships within 2 – 11 business days. for the past 450 years, tree - like branching diagrams have been created to show the complex and surprising interrelationships of organisms, both living and fossil, from viruses and bacteria to birds and mammals. this stunning book celebrates the manifest beauty, intrinsic interest, and human ingenuity of these exquisite trees of life. theodore w. pietsch has chosen 230 trees of life - from among thousands of possible contenders - dating from the sixteenth century to the present day. his arrangement gives readers a visual sense of the historical development of these diagrams and shows how, in darwin ' s words, " from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved. " pietsch ' s brief, accessible prose accompanies the diverse trees to fully reveal the engrossing history of human theories of evolution. over the centuries, trees of life appeared in a wide variety of forms ; some were revered as iconic while others incited intense controversy. the earliest examples were meant to portray the imagined temporal order in which god created life on earth. more recent scientific trees represent hypothetical histories of life. never before has the full spectrum of trees of life been brought together in a single volume. pietsch has spent decades collecting and researching the origin and meaning of these evolutionary trees and presents a visually breathtaking and intellectually brilliant history of the form.


- ignatius donnelly, “ atlantis : the antediluvian world ” ancient symbols like the cross and the swastika already existed in the americas long before the europeans came. egyptian symbols like the “ akeru ” back to back lion gods hieroglyph are found in olmec temples from ancient mexico. we have also found mayan art and glyphs in egypt. modern mayans and tribal egyptians both recognize the languages found in their countries as that of their ancestors and both can read much of it. we ’ ve discovered artwork 2 - 3000 years old clearly depicting negroes and caucasians in central america. the establishment remains silent on all these issues. the similarities between old world european and american peoples are vast and difficult to accept as mere coincidence. the use of cement, bricks, arches and advanced masonry / architecture is found on both sides of the atlantic, as well as roads, stone and suspension bridges ; metallurgy, ore mining of copper, tin, bronze, gold, silver, and iron ; sculpture, painting, engraving, agriculture, navigation, large sailing vessels, pottery, glasswork, and music ; both old and new worlders fashioned the same weapons like bows and arrows, spears, swords, battle - axes, darts and slings ; baptism, confession, penance all long existed on both continents. “ if we find on both sides of the atlantic precisely the same arts, sciences, religious beliefs, habits, customs, and traditions, it is absurd to say that the peoples of the two continents arrived separately, by precisely the same steps, at precisely the same ends. when we consider the resemblance of the civilizations of the mediterranean nations to one another, no man is silly enough to pretend that rome, greece, egypt, assyria, phoenicia, each spontaneously and separately invented the arts, sciences, habits, and opinions in which they agreed ; but we proceed to trace out the thread of descent or connection from one to another. why should a rule of interpretation prevail, as between the two sides of the atlantic, different from that which holds good as to the two sides of the mediterranean sea? if, in the one case, similarity of origin has unquestionably produced similarity of arts, customs, and condition, why, in the other, should not similarity of arts, customs, and condition prove similarity of origin? is there any instance in the world of two peoples, without knowledge of or intercourse with each other, happening upon the same invention, whether that invention be an arrow -


the sun ’ s energy is an incredible bounty. the energy contained in solar rays make their way through our filtering atmosphere and is critical to life on this planet... and is fundamental to human survival. it can also provide for our comfort. the use of the sun ’ s power in solar energy design is usually identified in 2 contexts - passive solar - that which uses natural processes without mechanical equipment and additional electrical or gas energy to operate, and active solar - that which uses nature ’ s resources with the inclusion of mechanical equipment and hardware driven by electricity and gas. all solar design starts from a simple base - passive solar first. what can be achieved by using all of the natural resources available to meet specific needs? this is the basic question and tenet of passive solar applications whether it be applied to heating and cooling a building, lighting, heating water, cooking, etc. passive solar applies both to buildings and equipment. sound fundamentals of good passive applications and integration can beneficial and are directly related to active solar equipment use and implementation : by meeting needs with no mechanical equipment dependent on external energy incorporation, in improving conditions which reduce the amount and size of equipment required to meet needs, by improving the conditions for active solar equipment applications, and in minimizing the commensurate costs that accompany the purchase and use of any equipment, solar or non - solar. in short, passive solar design and applications is the base which sets the conditions for effective active solar incorporation and use. passive and active solar applications should be considered as elements of the same palette - sort of the one - two punch of living with the sun, and the mutuality is undeniable. both rely on the same design considerations of orientation, access to the sun, behavior of materials, and appropriate use of site resources, and vary only in the inclusion external energy of electricity and gas. most active system guidelines even point out starting with passive considerations first. besides providing for direct meeting of needs, passive solar design is a primary basis for enhancing the quality of active solar systems. passive solar actions can result in the reduction of quantity of equipment needed to meet a particular task. for example, daylight is an available resource to meet illumination needs. good day lighting design of buildings uses that resource effectively, and reduces the need and cost of daytime artificial lighting and equipment. the beginning point consideration is at the end use side of things whether using traditional equipment or using solar equipment. considerable savings can be gained in applying natural energy actions to reduce the cost of both supplying equipment as well as running and maintaining it.


and equipment. the beginning point consideration is at the end use side of things whether using traditional equipment or using solar equipment. considerable savings can be gained in applying natural energy actions to reduce the cost of both supplying equipment as well as running and maintaining it. quite simply, the less work that needs to be accomplished by equipment, the less amount of equipment is needed, and the less it needs to run when used - this all translates to less cost for purchase of the equipment, and less on - going cost for running and maintaining. passive solar applications mitigate the quantity of active solar equipment needed, and resulting the tandem of both is optimal. information about the sun and how to use it effectively is common in both applications. traditionally, the term passive solar has been identified with heating and cooling of buildings, but it has a broader context and application. there is, of course passive solar heating and cooling of buildings. there is also passive solar water heating, solar cooking, natural lighting, passive solar heating of pools, and even passive solar devices which move things - equipment, air, etc. even the process of direct conversion of sunlight to electricity can be considered a “ passive ” action since it occurs through the appropriate use and placement of materials and capitalizes on the behavior of the combinations created, without infusing man - made energy sources and machines to make it work. knowledge and understanding of natural processes is the heart of passive solar. knowledge about the composition, attributes and behavior of sunlight and heat ; the behavior of heat flow ; the behavior and capacities of materials, both in nature and man - made ; the sun ’ s annual, seasonal, and daily movement ; diurnal and seasonal temperatures and conditions ; human sensory response and comfort ; the patterns of nature and of people ; and the physiology and psychology of the interaction between people and nature, all are applied to effective solar application and utilization. nature ’ s contribution - a gift that also keeps us on our toes intense heat, cold ) the conditions that nature provides, in the form of climate, is variable. cold in the winter, hot in the summer, nice other times of the year. arizona climate covers the entire spectrum with extremes at the desert and mountain locations. simultaneously, nature also provides the tools for mitigation of the extreme conditions. sunlight and materials for a warming system ; breezes, water, earth, gravity, and materials for a cooling system. it is the application of these resources into a system that addresses conditions that makes passive, and active, solar so effective. the sun ’ s available


for a warming system ; breezes, water, earth, gravity, and materials for a cooling system. it is the application of these resources into a system that addresses conditions that makes passive, and active, solar so effective. the sun ’ s available energy varies in amount and impact through the year. the amount and intensity of energy from the sun that impacts the earth is affected by the composition of the earth ’ s atmosphere, and the angle of the solar radiation waves. the more dense the atmosphere, whether by clouds or smog, the less solar energy reaches the ground. additionally the more directly perpendicular the sun is to the earth ’ s surface, the more concentrated the energy is in a given area and the more intense its impact. the highest capitalization of solar radiation for heat is when surfaces are perpendicular to the sun, allowing the most density of radiation at a given point. | we know the sun ’ s position every day of the year and the amount of radiation that position provides, both to the earth ’ s surface, as well as to various positions of building walls and / or equipment. a south facing wall, or piece of equipment gets more energy from the sun than any other position. an angle directly perpendicular to the sun gets more energy per square foot than one that is at an angle. the sun is less available in the winter ( shorter days ) than in the summer. there is less solar energy availability in the winter than the summer due to the sun ’ s position at an angle to the earth and therefore more atmosphere to penetrate. we also know that cool air settles and warm air rises, and that this action occurs with fluids like water. we know about heat flow and capabilities of materials in their capacity to absorb, hold, and give up heat. we know how to let sunlight in, how to capture and create air movement for cooling, and prevent unwanted heat. the built environment in tune with nature | passive solar buildings are environmentally responsive and use nature ’ s elements in providing shelter and comfort to people in a manner that is healthy and minimally destructive of the environment ; are non - depleting of natural resources ; and use the building itself in the comfort creating process. they are characterized throughout the recent years with terms as “ sustainable ”, “ renewability ”, and “ green ”. quite simply, these terms refer to the same thing - a nature incorporating, comfort generating, security providing environment in which the building composition itself is the “ machinery ” that creates protection, health and comfort, and incorporates appropriate solar equipment to attain higher degrees


. quite simply, these terms refer to the same thing - a nature incorporating, comfort generating, security providing environment in which the building composition itself is the “ machinery ” that creates protection, health and comfort, and incorporates appropriate solar equipment to attain higher degrees of performance. | arizona history is replete with examples of people living with the sun - both in using it as a resource as well as dealing with it ’ s negatives. passive solar was integrated into arizona architecture and buildings, both in private and public buildings. while incorrectly called arizona ’ s first solar building, ( there is no indication that this was a conscious effort since a number of cliff dwellings built in the same period by the same people do not show the same kind of solar application ) the construction of montezuma ’ s castle does embody some solar principles of orientation, thermal mass, “ overhangs ” for summertime shading, and south facing winter courts | desert buildings used proper orientation, thick masonry walls, natural cross ventilation, indoor and outdoor living spaces, and natural and man - made shade for summer cooling, and south facing courts, and windows with tile floors which, when coupled with the thick masonry walls, provided for capture and storage of warmth during winter conditions. higher elevations of arizona utilized the similar principles with differing amounts of wall mass and windows for heating, and porches and cross ventilation for summer evening relaxation and sleeping. | arizona desert buildings, both private and public, used passive means of shading to provide respite from the intense sun. passive solar equipment, in the form of water heaters, were prevalent in arizona as well as southern california. the historic ellis - shackleford house in phoenix and the historic tempe bakery had direct gain solar hot water heaters. passive solar energy - prelude to solar equipment consideration there are a number of passive energy fundamentals which can be considered in reducing the amount of equipment and / or its ’ operation. orientation - it ’ s a necessary thing... like all direct solar applications, capturing the sun as a resource is as simple as providing for its clear path to where it can do its work - be it heating water, cooking food, or warming a space. orientation is a fundamental concept of solar use for passive, and active, systems - | orientation of a solar device | | or orientation of a building | | or a solar cooker | orientation and a direct relationship with the sun is the first rule of solar energy use when trying to capitalize on its heat providing attributes. the sun ’ s traverse


a solar device | | or orientation of a building | | or a solar cooker | orientation and a direct relationship with the sun is the first rule of solar energy use when trying to capitalize on its heat providing attributes. the sun ’ s traverses the sky every day - in the winter it is a low and short path and in the summer a long and high path - and even though the sun ’ s location is constantly changing, it is a predictable path that can be used in incorporating the sun ’ s energy to meet needs, and to exclude when we want to minimize the same. applied knowledge of both the sun ’ s movement, position at any given time, and time of the year, as well as impact in the form of radiation ( solar incidence ), enables us to take advantage of these attributes to meet needs, and to make use of our buildings and our equipment more effective and efficient. proper orientation is critical to optimizing the solar resource. a properly oriented building can optimize solar gain for human comfort heating, and with proper shape and overhangs can minimize summertime overheating. likewise, properly oriented solar equipment, be it a solar water heating panel or a photovoltaic electricity generating panel, will have optimum production and minimal negative impact. using natural winter heating and minimizing summer heat impacts reduces the size of heating and air conditioning equipment as well as the energy, traditional or photovoltaic, needed to provide energy to these systems. additionally, proper orientation allows for full benefit of the operation of electric solar panels and maximizing solar water heating operations. | proper building orientation also eases the integration of active solar equipment into the building form and shape, and mitigates the conflicts of solar installations contested in numerous subdivisions regulations. proper orientation with direct exposure to the south, is best for passive solar heating of building spaces as well as the operation of solar equipment ( water heaters, pv panels, cookers, pool panels, etc. ). slight adjustments to the east or west of south allow for earlier or later use of the sun ' s energy, or for mitigating it. form - it ’ s a right thing | solar buildings employ a form and shape that is responsive to the elements of nature that impact upon it, as well as the solar equipment that is part of the passive / active solar approach. elongated along the east west axis, an arizona building optimizes the southern exposure for good wintertime direct heating, while minimizing the east and west exposures which are


location planning extends to the integration of solar equipment as a building component by reducing piping runs and the commensurate “ line losses ”, thereby allowing more of the solar heat captured in a water heating system to get to the storage and / or use point. materials - it ’ s the smart thing : all solar heating and cooling systems are based on the ability to gather and store solar energy within a material for a period of time. this is accomplished by using a material which will hold heat until it is needed for heating, or capturing heat that will be dispelled at a later time. solar water heaters use water. solar buildings use their own structure - floors, walls, even roofs. of course, some materials are better for this purpose than others. glass, wood, and insulation are not good holders of heat. more dense materials like earthen materials ( adobe, stone, brick, etc ) and man - made materials like concrete are very good. this attribute is called thermal mass. heating application of thermal mass is to select material ( s ) that will absorb heat from solar exposure during the day, hold that heat for a time during non - solar periods, then give it up as conditions warrant. the same action can be incorporated for building cooling. as an area heats up, heat can be absorbed into the thermal mass material in the walls, floor or ceiling, like a thermal sponge, then held until evening time where effective cooling practices using cross ventilation, night sky radiation and even whole house mechanical ventilation ( remember - nighttime electricity rates are lower than daytime ). this action is based upon fundamental principles of thermal transfer. nature is always seeking to even out things so if there is a “ difference ”, there is a natural action which moves to make every thing the same or to even out. in the case of heat transfer, heat migrates to cold, so in a building, hot walls will radiate into cold spaces, and conversely, hot, summertime spaces will have their heat migrate to cooler walls. an analogy that has been used is one of 2 buckets of water - 1 full and one empty. if they are placed at an equal height, and there is a connection between the 2, below the water line of the first, water will flow to the second until there is an equal amount in the second where all action will stop because a balance has passive solar buildings utilize the very fabric of the building as part of the comfort system for heating and cooling, and the addition of active solar system for running naturally heated or cooled


is an equal amount in the second where all action will stop because a balance has passive solar buildings utilize the very fabric of the building as part of the comfort system for heating and cooling, and the addition of active solar system for running naturally heated or cooled water to through a thermal mass wall, floor, or roof structure enhances the performance of the system by the additional thermal mass capacity and heat capture / transfer attributes of the windows - it ’ s the clear thing. one of the major design considerations affecting a building ’ s energy consumption is the location and size of windows. windows are the weakest point of the building envelope and usually the leakiest when it comes to energy, both in terms of losing heat in the winter, and gaining heat in the summer. a square foot of glass will lose 12 time more energy than a wood wall with insulation. as a rule, windows should be located primarily on the south side where they can be used as part of the heating system, as well as provide for natural lighting. that is the side where the sun is!. east and west sides of desert buildings should have minimal or no windows since these are the 2 worst exposures for early morning and late afternoon summer sun. east windows allow for early summer morning heat up and west windows allow for late afternoon negative impacts. solar windows should be sized in accordance with the heating and cooling performance of the building. typical oversizing to have the “ feel of the great outdoors ” is not an optimal situation when it comes to solar design. clerestorey windows are a design tool for getting sunlight benefits ( heating and lighting ) to areas not able to be located at the south face. clerestories also provide a mechanism for diffusing the direct impact of sunlight and moderating glare. additionally, operable clerestorey windows are a good device for house ventilation cooling in the summer. reverse clerestories, those opening to the north can be a benefit in desert conditions. facing north, they provide even natural light to interiors and their angled backs can be a perfect mounting structure and angle for solar equipment like photovoltaic and solar water heating panels. thermal decompression - it ’ s the healthy thing a building trying to maintain a comfortable internal temperature will always be in conflict with the temperatures adjacent to the exterior. heat always moves to cold - in the winter, interior warmth is moving toward the exterior cold. in the summer, the external heat is trying to move to the interior coolness. in both situations, the greater the difference in temperature


to the exterior. heat always moves to cold - in the winter, interior warmth is moving toward the exterior cold. in the summer, the external heat is trying to move to the interior coolness. in both situations, the greater the difference in temperature between inside and outside conditions, the faster the movement of heat and the greater the amount of heat moved, and the more equipment is required to mitigate conditions. in temperate times when inside and outside are at or near the same temperatures, there is minimal movement and therefore minimal need for equipment. add to this the fact that sudden and abrupt changes in temperature are not positive to the human body which has to react rapidly to changed conditions, and good passive site planning of thermal decompression is important for not only comfort, but for health. thermal decompression simply means that there is layering of vegetation, landscape features, and built elements that gradually temper the environment to a point where the temperatures adjacent to the building are much closer to its internal temperature. this decompression approach establishes a condition where the difference between the internal temperature and the temperature on the building skin are much closer, so less heat is gained ( or lost ) and less mitigating equipment, and commensurate energy, is required. passive solar applications - it ’ s first thing natural lighting - | the sunlight received by a building will provide more than sufficient illumination to meet daily needs. use of day lighting is a passive solar application. the sun ’ s capacity to provide light, when integrated correctly in a building, means no need to use artificial lighting during the day, which means no energy used for those lights, which means no utility cost, except at night when the sun doesn ’ t shine. solar building design incorporates day lighting strategies of letting light into all spaces either directly with proper window placement, clerestories and even skylights, or indirectly with light reflecting color choices, light shelves, and transparent and translucent walls. this glazing has dual benefit - while providing for illumination, it can also provide for wintertime heating. good passive design then incorporates both attributes of sunlight - illumination and heating, and the building construction and finishes are used to capitalize on both. light colored surfaces and transparent / translucent interior panels for “ bouncing ” or directing sunlight for illumination, and dark, thermal mass surfaces for absorbing the sun ’ s rays for heating. multi - faceted and multi - applicable, day lighting design is an effective passive solar approach which has a direct impact on the building ’ s however, addition of a


, and dark, thermal mass surfaces for absorbing the sun ’ s rays for heating. multi - faceted and multi - applicable, day lighting design is an effective passive solar approach which has a direct impact on the building ’ s however, addition of a solar electricity generation system ( photovoltaics ) allows for the capture of daytime sunlight and its transformation into electricity, which can then be stored and used in the night. add to this the use of efficient fixtures and systems, and costs in both resources and dollars are further reduced. water heating - batch or integrated collector / storage ( ics ) system simply water in a tank within a container and exposed directly to the sun. this is the basis of batch / breadbox, systems which combine collection, heating, and storage of water into a single component. direct heating of the storage tank or tanks, makes this system compact, simple, and effective. these units are called a passive systems because they do not rely on equipment to make them function. when hot water is removed, it is replaced by an equal amount of " new " water. the " batch " approach has been used for quite some time and improvements in design have enhanced their effectiveness in increasing water heating capabilities. newer systems use a number of small - diameter connected storage tanks connected to expose more of the water surface to the sunlight, heating the water at a faster rate. in some cases reflectors are integrated, bouncing more of the sun ' s rays onto the water tank, and when the sun falls, the reflectors, made of highly insulating material, fold over the glazing to insulate the tank. some systems use evacuated glass tubes ( like a thermos bottle ) around the collector to keep heat loss to a minimum. thermosyphon systems. | hot water rises and cold water settles. this is because hot water is less dense than cold water due to its molecular " excitement " in being heated. in a typical water heater, colder water is at the bottom of a tank. when it is heated by the heating element or burner, it becomes less dense and rises to the top of the tank, while being replaced by cooler, settling water, which is, in turn heated, rises, etc.. this cycle is called a convective action. a thermosyphon solar water heating system incorporates natural convection to move fluid heated by the collector to a storage tank. in order to do this naturaly, the collector is located at some point below the storage storage tank. as the fluid at


a thermosyphon solar water heating system incorporates natural convection to move fluid heated by the collector to a storage tank. in order to do this naturaly, the collector is located at some point below the storage storage tank. as the fluid at the bottom of the storage tank cools ( more dense ) it flows to the bottom of the collector where it is reheated making it rise back to the top of the storage tank. this process is continuous. as a result, thermosyphon systems do not need pumps and for that reason they are considered a passive system - that system that does not rely on equipment to make it function. | passive solar applications for heating and cooling a building mitigate expensive heating and cooling with conventional equipment driven by electricity and gas, and good passive design reduces the energy consumed and the allied cost of utility resources to maintain comfort. there are basic elements of passive energy buildings which use the form and materials to provide comfort. some of these are applicable to solar equipment design and use, even to the point where there is solar equipment which are passive in their operation - i. e. thermal energy flows in the system naturally. solar water heating is one type of equipment that can be a passive solar piece of equipment. a “ batch ” water heater and a thermosiphon water heater can be considered passive solar equipment - since they do not rely on out side energy source to make them function. of course, when talking about passive and active solar, optimum conditions and control occur best when these two are coupled. basics of passive applications are rooted in dealing with the sun ( exposure to and capture of the sun ’ s energy when we want heat ; protection from the sun when we want cooling ), the materials used ( for effective capture, storage, and use ), and natural processes of physics for both ). every passive system for solar heating, whether it is heating water, or heating a building, requires exposure to the sunlight and trapping it - this is done by glazing - windows for a building and glass covers for solar panels. every passive system is dependent upon materials which will absorb the sun ’ s heat, store a good quantity of it and easily distribute it. in a building, the effective material can be the structure itself, in the form of thermal mass. thermal mass is characterized by those dense materials like concrete and earthen materials, and also by an extremely good material - water. these materials can readily absorb solar radiation, hold its warmth, and easily and evenly give it up to adjacent


of thermal mass. thermal mass is characterized by those dense materials like concrete and earthen materials, and also by an extremely good material - water. these materials can readily absorb solar radiation, hold its warmth, and easily and evenly give it up to adjacent spaces. | heat capture, storage and distribution follow a natural and predictable behavior. sunlight heats the surfaces it strikes. the amount of heat held within the material depends on the material composition - straw is a terrible holder, concrete is a better holder. when sunlight is no longer available the material gives its ’ captured heat to adjacent cooler conditions. generally there are 3 passive heating building concepts - direct gain, indirect gain and isolated gain these concepts have inherent within them cooling strategies and applications as well. direct gain - simply stated, sunlight comes directly through windows into the space to be heated. the building materials struck by the sunlight are thermal mass materials - concrete / tile floor, masonry walls, or even strategically placed containers of water. building windows act in exactly the same way as solar panel glazing - they let the sunlight ( short wave radiation ) in and inhibit heat ( long wave radiation ) from escape. direct gain design system is always working, letting in not only direct sunlight but also the diffuse light of cloudy days, and the intense light of summer. like any system, optimization is the goal - so the building eaves and overhangs become a designed - in optimizing element - summertime conditions, when heating is not required, are mitigated by keeping the sunlight off of the windows via the overhang, while in the winter, the sun is much lower in the sky and can easily skirt under the building ’ s brow. heating is quite simple in this approach - sunlight, absorbed by the thermal mass materials, solid and / or liquid, is stored as heat. when the space cools in the evening, the heat migrates to the cooling spaces directly ( radiation ) or by air movement across the surface of the material ( convection ). for this approach, a careful consideration of the site, solar energy availability, and seasonal conditions, are all necessary to determine the appropriate amount of windows and thermal mass. too many windows in an arizona desert setting will result in a human cooker ; too few windows in a rim setting will result in not enough capture. this system has worked effectively in arizona designs, as well as that sunniest of place of liverpool, england. for effective cooling, such as the desert setting, direct gain avoidance is the rule, but the thermal mass of the building can still


capture. this system has worked effectively in arizona designs, as well as that sunniest of place of liverpool, england. for effective cooling, such as the desert setting, direct gain avoidance is the rule, but the thermal mass of the building can still be used in the cooling cycle. the materials, by nature of their thermal mass attribute, remain cool ( or can be cooled during nighttime conditions - naturally by cross ventilation, or mechanical y by lowest cost energy driven fans ). this coolness allows their absorption of unwanted heat in the building - acting as a sort of thermal sponge, moving heat away from people and holding to the evening, where cross ventilation or even whole house fans can dispose of the captured heat. control of direct gain systems is done with the addition of movable insulation, either on the exterior or with interior blinds, and cross ventilation planning with placement of low wall vents on the cool side of the building, and high wall vents on the warm side of the building. indirect gain - indirect gain is an “ next step ” of a direct gain system. sunlight penetrates south facing windows, then strikes thermal mass located behind the window and between the sun and living space. there are basically three types of indirect gain systems, each defined by where the thermal mass is located. the three strategies are : thermal wall and plenum thermal wall and plenum - south facing windows front a thermal mass wall of masonry, and / or water, placed directly behind to create a vertical plenum or chase. the sun side of the thermal wall is typically dark to capture more of the solar spectrum. this mass absorbs, stores and distributes heat while acting as a buffer to the interior spaces, and moderates temperature changes and provides for extended use of thermal gain well into the evening. sunlight passes through the glass and converts to heat energy as it impacts the thermal mass and is absorbed, slowly saturating or moving through the mass until it radiates into the living space - the wall is a delayed action radiator. at the same time the air trapped between the windows and the mass heats up, and the addition of vents at the top and bottom of the wall allow for direct passive heating. warmed between the glass and the wall spills into the living space through the opened upper vent and since nature abhors a vacuum, cooler room area enters the plenum through the bottom vent, and is heated by the sun warmed wall, rises, spills into the room and is replaced by cooler air again, and this natural convection process


since nature abhors a vacuum, cooler room area enters the plenum through the bottom vent, and is heated by the sun warmed wall, rises, spills into the room and is replaced by cooler air again, and this natural convection process continues as long as there is sunlight. there are a number of examples of this application - the trombe wall which uses masonry, earthen materials like, and water like steve baer ’ s water barrel. variations in thermal mass wall materials vary from commercial water tubes to incorporation of stone. the baer barrel wall installation provides for optimizing the heating capabilities as well as cooling of the adjacent spaces with the addition of movable insulating panels. during winter conditions, insulating panels are moved to allow for solar access to heat the water barrels, then at night the insulating panels are raised to cover the glazing and the barrels radiate their warmth to the space. in the summer heat, the insulation is raised and the barrels, with their cool water, act as absorbers, pulling unwanted heat from the spaces. at nightfall, the insulation is lowered, and the barrels give up their stored heat to the exterior by radiation and convection. the water, now cooled, is ready to act as a cooling absorber the next day. sunspaces are a combination of direct gain and thermal wall systems, utilizing both approaches in tandem with a dedicated direct gain area ( sunspace ) adjacent ( fronting ) the living space, with a thermal wall placed between the two. the sunspace, has extensive south glazing and large daily fluctuations, while the adjacent living space is protected from these fluctuations by the thermal wall separating the spaces. vents or operable doors and windows in the thermal wall allow warmed sunspace heat to circulate to adjacent living spaces by natural convective actions during the day, and radiate the absorbed sunspace heat to the living spaces in the evening. an additional usable area, sunspaces are often used as solar greenhouses. temperature control is best achieved with operable venting windows and cross ventilation. sunspaces - green houses : thermal roof - the thermal roof approach places thermal mass on the roof rather than at a wall, and is very effective as both a passive heating and cooling strategy. the system is both a radiator and an absorber and replaces standard heating and cooling mechanical systems and the inherent ductwork distribution system. using water as thermal mass, roof ponds are constructed directly on top of heat conducting ceilings of metal pans or