UK PubMed Central (United Kingdom)

Although deep-sea cephalopods are key marine organims, their feeding ecology remains essentially unknown. Here, we report for the first time the trophic structure of an assemblage of these animals (19...Full Text Available

UK PubMed Central (United Kingdom)

Natural accumulations of skeletal material (death assemblages) have the potential to provide historical data on species diversity and population structure for regions lacking decades of wildlife monitoring,...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Maldives comprise some of the most characteristic and significant atoll systems, but the meiobenthic assemblages of these islands are still largely unknown. A study on meiofauna was conducted on three Maldivian sandy back-reef platforms differently exposed to stronger westerly monsoons. Clear high energy effects of the waves causing currents and erosions were observed at the completely exposed and isolated offshore reef of Thoddoo Island. Wave energy of medium intensity was confirmed at Rasdhoo by depositional structures (finolhu), while a medium to low energy level was recorded at Gulhi on the basis of the presence of a low sandy bar. The meiofaunal assemblage counted 17 major taxa. Copepods and nematodes were dominant, followed by platyhelminthes and polychaetes. The nematode assemblage ...

Science.gov (United States)

... describe the relationship (Peake and Quinn, 1993). The power model was considered best if the R2 from this ... when stone abundance was low (Fig. 2). The power model best described the nonlinear relations...

CERN Document Server

Community ecologists are principally occupied with the proposition that natural assemblages of species exhibit orderliness and with identifying its causes. Plant-pollinator networks exhibit a variety of orderly properties, one of which is 'nestedness'. Nestedness has been attributed to various causes, but we propose a further influence arising from the phylogenetic structure of the biochemical constraints on the pollen diets of bees. We use an artificial assemblage as an opportunity to isolate the action of this mechanism. The properties of the network that we studied are consistent with the proposition that nestedness is caused by the phylogeny of diet range in bees, but the claim is preliminary and we propose that valuable progress in understanding plant-pollinator systems may be made through applying the techniques of chemical ecology at the community scale.

International Nuclear Information System (INIS)

A database has been developed before and after the dewatering of the Meigs number-sign 31 deep coal mine in Meigs County, Ohio, three years ago. This strategy was to compare potential recovery of the watershed in the mainstem of Leading Creek as well as to reconnaissance the tributaries for point-source input into the creek. After the dewatering process, #approx# half of the 31-mile Leading Creek mainstem received a discharge of conductivity, low pH, high metals (iron, manganese, copper, aluminum), and total suspended solids (TSS). Most forms of aquatic life in the creek were depleted in the impacted areas, but recovery has been encouraging. Relative fish abundance has returned to pre-event levels, while benthic macroinvertebrates show recovery in two key stream segments. Reconnaissance of the watershed indicated that the system is uniquely segregated with high sedimentation from agricultural input in the upper half and abandoned mined land (AML) discharges in the ...

International Nuclear Information System (INIS)

Benthic biological samples were taken in 1977 from the vicinity of the Farallon Islands radioactive waste disposal sites for characterization of the infaunal macroinvertebrates and foraminifera. A total of 120 invertebrate species were collected, of which 75 species (63 percent) were polychaetes. Forty-three of these polychaete species have not previously been reported from depths greater than 1000m. A total of 1044 macroinvertebrate specimens were collected of which 54 percent were polychates. Only the nematods were present at all six benthic stations, but the community structure was dominated by the polychaetes Tauberia gracilis, Allia pulchra, Chaetozone setosa, and Cossura candida. Living and dead foraminifera were reported. The possible role of polychaetes in bioturbation and in the marine food chain is briefly discussed with respect to the various polychaete feeding mechanisms.

Wastenet

...Assemblages of plants and invertebrate animals of tumulus (organic mound) springs of the Swan Coastal Plain Assemblages of plants and invertebrate animals of tumulus ...organic mound) springs of the Swan Coastal Plain [Skip navigation links] About us | Contact us | Publications |...ecological communities Assemblages of plants and invertebrate animals of tumulus (organic mound) springs of the Swan Coastal Plain Advice to the Minister for the ...of the 'Assemblages of plants and invertebrate animals of tumulus (organic mound) springs of the Swan Coastal Plain' community sufficient to distinguish it from ...

British Library Electronic Table of Contents (United Kingdom)

The southern Alaska convergent margin contains several small belts of sedimentary and volcanic rocks metamorphosed to blueschist facies, located along the Border Ranges fault on the contact between the Wrangellia and Chugach terranes. These belts are significant in that they are the most inboard, and thus probably contain the oldest record of Triassic-Jurassic northward-directed subduction beneath Wrangellia. The Liberty Creek HP-LT schist belt is the oldest and the innermost section of the Chugach terrane. Within this belt lawsonite blueschists contains an initial high-pressure assemblage formed by lawsonite+phengite+chlorite+sphene+albite+/-apatite+/-carbonates and quartz. Epidote blueschists are composed of sodic, sodic-calcic and calcic amphiboles+epidote+phengite+chlorite+albite+sphen...

Science.gov (United States)

... sur un site. Ces espèces présentent un vaste spectre de régimes alimentaires couvrant plusieurs niveaux trophiques et ... ...

International Nuclear Information System (INIS)

Planktivores, zooplankton grazers, and macrobenthos were studied to determine how changes in animal community structure may alter the flow of material in Dunham Pond, CT. Chaoborus and chironomid larvae were studied to determine how they affect the flux of matter across the sediment/water interface. This was done by incubating undisturbed cores in situ and relating changes in water chemistry to larval density. The log-transformed flux rates of iron, manganese, and phosphorus were linearly related to larval biomass. Functional groups may be successfully used to predict rates of material flow. Changes in the mass of macroinvertebrates affect the flux rates of redox-active substances across the sediment/water interface. The use of population densities and feeding characteristics to estimate trophic transfer in Dunham Pond indicate that (1) visual planktivory by larval perch may result in overutilization of prey, (2) ambush planktivory by ...

International Nuclear Information System (INIS)

In 1990, field studies of water quality and stream macroinvertebrate communities were initiated in Sandia Canyon at Los Alamos National Laboratory. The studies were designed to establish baseline data and to determine the effects of routine discharges of industrial and sanitary waste. Water quality measurements were taken and aquatic macroinvertebrates sampled at three permanent stations within the canyon. Two of the three sample stations are located where the stream regularly receives industrial and sanitary waste effluents. These stations exhibited a low diversity of macroinvertebrates and slightly degraded water quality. The last sample station, located approximately 0.4 km (0.25 mi) downstream from the nearest wastewater outfall, appears to be in a zone of recovery where water quality parameters more closely resemble those found in natural streams in the Los Alamos area. A large increase in ...

International Nuclear Information System (INIS)

The thermal regime immediately downstream from bottom release reservoirs is often characterized by reduced diel and seasonal (winter warm/summer cool) conditions. These unusual thermal patterns have often been implicated as a primary factor underlying observed downstream changes in the species composition of aquatic macroinvertebrate communities. The potential mechanisms for selective elimination of benthic species by unusual thermal regimes has been reviewed. Although the effects of temperature on the rate and magnitude of larval growth and development has been included in the list of potential mechanisms, only recently have field studies below dams focused on this interrelationship. This study investigates the overall community structure as well as the seasonal pattern of larval growth and development for several univoltine species of insects in the Delaware River below or near the hypolimnetic discharge of the Cannonsville and Pepeacton ...

International Nuclear Information System (INIS)

The goal of the Fifteenmile Creek Habitat Improvement project is to improve wild winter steelhead habitat in the Fifteenmile Creek Basin. This goal was addressed under the Columbia River Basin Fish and Wildlife Program, Measure 703 (c) (1) - Action Item 4.2. Construction of fish habitat structures was completed on approximately 3.5 miles of Eightmile Creek and on approximately 8.5 miles of Fifteenmile Creek. A total of 15,435 yds of rock was placed to improve rearing and spawning habitat, and to improve water quality and reduce siltation. Riparian protection fencing was completed on 1.8 miles of Dry Creek, approximately 1.75 miles on Eightmile Creek, and 4.75 miles on Fifteenmile Creek. Approximately 10 miles of stream will receive protection from the 8 miles of new fencing installed and 6.5 miles of abandoned fence repaired. Irrigation withdrawal screens were installed at six irrigation pump withdrawals. These screens functioned satisfactorily during the ...

UK PubMed Central (United Kingdom)

Here we use published 16S rRNA gene sequences to compare the bacterial assemblages associated with humans, other mammals, other metazoa, and free-living microbial communities spanning a range...Full Text Available

Science.gov (United States)

... verges of a two-lane highway in continuous Jarrah Eucalyptus marginata forest of south-western Australia. Midway during this ... Birds were recorded from the beginning of continuous Jarrah Eucalyptus marg...

Wastenet

... Contrary to this definition, abiotic environmental factors are those in which no organisms participate - e.g. the geological underground, light, temperature and heat. Biotope The biotope is an area of uniform environmental conditions providing living place for a specific assemblage of plants and animals....

Energy Technology Data Exchange (ETDEWEB)

The grey-black mudstones of the Sonehat Formation form part of the Middle Jurassic fill of the Jameson Land Basin in East Greenland. The formation is exposed in the southernmost part of the north south-trending, Mesozoic rift system in East Greenland that was part of the epeiric seaway betaveen East Greenland and Norway. Sedimentological observations of the Sortehat Formation indicate deposition in an offshore marine setting that was typically low energy and periodically oxygen-deficient but was influenced by storm currents on occasion. Detailed palynological studies of the Sortehat Formation have resulted in the definition of theee palynological assemblage zones recognised at four localities, namely Enhjoerningen Dal and Pelion (north Jameson Land), the type section at Sortehat (central Jameson Land) and Albuen at Neill Klinter along Hurry Inlet (south-east Jameson Land). In stratigraphic order, these zones are termed the Botryococcus ...

International Nuclear Information System (INIS)

Laboratory dose-response experiments with organophosphate and pyrethroid pesticides, and dose-response experiments with increasing particle loads were used to determine which of these stressors were likely responsible for the toxicity and macroinvertebrate impacts previously observed in the Salinas River. Experiments were conducted with the amphipod Hyalella azteca, the baetid mayfly Procloeon sp., and the midge Chironomus dilutus (Shobanov, formerly Chironomus tentans). The results indicate the primary stressor impacting H. azteca was pesticides, including chlorpyrifos and permethrin. The mayfly Procloeon sp. was sensitive to chlorpyrifos and permethrin within the range of concentrations of these pesticides measured in the river. Chironomus dilutus were sensitive to chlorpyrifos within the ranges of concentrations measured in the river. None of the species tested were affected by turbidity as high as 1000 NTUs. The current study shows that pesticides are more ...

Energy Technology Data Exchange (ETDEWEB)

Here we examine Fe speciation within Fe-encrusted biofilms formed during 2-month seafloor incubations of sulfide mineral assemblages at the Main Endeavor Segment of the Juan de Fuca Ridge. The biofilms were distributed heterogeneously across the surface of the incubated sulfide and composed primarily of particles with a twisted stalk morphology resembling those produced by some aerobic Fe-oxidizing microorganisms. Our objectives were to determine the form of biofilm-associated Fe, and identify the sulfide minerals associated with microbial growth. We used micro-focused synchrotron-radiation X-ray fluorescence mapping (mu XRF), X-ray absorption spectroscopy (mu EXAFS), and X-ray diffraction (mu XRD) in conjunction with focused ion beam (FIB) sectioning, and highresolution transmission electron microscopy (HRTEM). The chemical and mineralogical composition of an Fe-encrusted biofilm was queried at different spatial scales, and the spatial relationship between primary ...

British Library Electronic Table of Contents (United Kingdom)

Diet overlap and niche breadth are well-known species traits from trophic ecology that can assist in explaining how species interact and coexist as well as the ecological mechanisms that influence biodiversity. In the present study, we analyzed the relationships between these trophic variables and indicators of resource availability with some attributes of fish assemblages (species richness, Shannon diversity index, evenness, density and individual body size). The physical and chemical characteristics of the biotopes (topography, water quality and conservation of slopes) were examined to identify possible patterns. Monthly sampling using electrofishing was conducted in 2003 along five streams located in the Cuiab? River watershed. The relationships between environmental variables and attri...

International Nuclear Information System (INIS)

The morphological development of oxide scales formed on a low Al substituted #beta#-sialon (z=0.2) oxidised for time periods up to 1024h at 1350 C is discussed in relation to oxidation kinetics. The oxidation process is observed to be accompanied by changes in both the phase assemblage of the external layers and their morphology. Thus as the time of oxidation increases beyond 64h the cristobalite-#beta#-yttrium disilicate phase assemblage changes to cristobalite plus #beta#- and #gamma#-yttrium disilicate. In addition to the changes observed for the surface layers, differences are observed in the morphologies of the polished cross-sections. These changes are consistent with an order of magnitude decrease in oxidation rate. (orig.).

International Nuclear Information System (INIS)

Salinisation of freshwater has been identified as a serious environmental issue in Australia and around the world. Protective concentrations (trigger values) for salinity can be used to manage salinity impacts, though require locally relevant salinity tolerance information. 72-h acute salinity tolerance values were determined for 102 macroinvertebrates collected from 11 locations in four biologically distinct freshwater bio-regions in Northeast Australia and compared with sensitivities observed in Southeast Australia. The salinity tolerance of individual taxa was consistent across Northeast Australia and between Northeast and Southeast Australia. However, two distinct communities were identified in Northeast Australia using distributions of the acute tolerance values and a calculated index of salinity sensitivity. Salinity trigger values should therefore be representative of local or regionally relevant communities and may be adequately calculated using sensitivity ...

International Nuclear Information System (INIS)

Continuing high rates of acidic deposition in the eastern United States may lead to long-term effects on stream communities, because sensitive catchments are continuing to lose anions and cations. A two-year study of the effects of pH and associated water chemistry variables on detrital processing in three streams with different bedrock geology in the Monongahela National Forest, West Virginia were investigated. Leaf pack processing rates and macroinvertebrate colonization and microbial biomass (ATP concentration) on the packs in the three stream were compared. It was found that macroinvertebrate and microbial communities differed both among streams that differed in their capacity to buffer the effects of acidic precipitation and among years in the same stream; these differences in biotic communities were not large enough to affect rates of leaf processing between the two years of the study, but they did significantly affect processing rates ...

International Nuclear Information System (INIS)

Four very common long term mineralogical changes in salt formations are discussed in the view of the safety considerations for underground repositories. Two of these processes, the 'Hartsalz' and 'Carnallite' dissolution were studied in two scale in situ experiments. The results are presented and compared with the results of the geochemical modelling with the computer code EQ3/6. Furthermore the reactions leading to the formation of the gypsum cap rock on the top of the Zechstein salt formations and to the polyhalitization of anhydrite are discussed. Geological field observations and mineral assemblages agree well with the results of the geochemical modelling employing the Pitzer formalism along with the Harvie, Moller and Weare database. We conclude that once the mechanisms of the chemical reactions are well understood it becomes possible to evaluate realistically whether such processes, when encountered in the repository, are still active or whether they are ...

British Library Electronic Table of Contents (United Kingdom)

The Monte Carlo ray-tracing method is applied and coupled with optical properties to predict the radiation performance of solar concentrator/cavity receiver systems. Several different cavity geometries are compared on the radiation performance. A flux density distribution measurement system for dish parabolic concentrators is developed. The contours of the flux distribution for target placements at different distances from the dish vertex of a solar concentrator are taken by using an indirect method with a Lambert and a charge coupled device (CCD) camera. Further, the measured flux distributions are compared with a Monte Carlo-predicted distribution. The results can be a valuable reference for the design and assemblage of the solar collector system.

International Nuclear Information System (INIS)

From June to September 2004 a water research was carried out in six stations that are located at the following microbasins: La Laucha (S1), La Lejia (S2, S3 and S6) and La Rastrojera (S4 and S5). Those microbasins are localized at the Durania municipality in Norte de Santander Department. This study was carried out in order to evaluate water quality at the microbasins above mentioned using macroinvertebrates as bioindicators. For physical, chemical and microbiological parameters a sample was taken at each station. The results were correlated with biologic parameters and it may be concluded that the station 5 closer to the town of Durania is the most polluted by organic matter and that those stations that belong to the ritral zone are less contaminated. The final result showed that the stations 1. 2. 3. 4 and 6 have conditions that can be classified as very clear to clear water and station 5 presents high contamination level.

International Nuclear Information System (INIS)

The objectives of this paper are to document the physicochemical and aquatic toxicological quality of a beneficial-use produced-water discharge and its effect on a receiving stream in Wyoming. Fish and water-flea survival, growth, and reproduction tests indicated that the discharge and all other sampling stations passed the state effluent biomonitoring acute toxicity testing endpoints. while benthic macroinvertebrates were absent at the discharge point designated by the Natl. Pollutant Discharge Elimination System (NPDES), productive and reproducing populations were present at all other downstream and mixing-zone stations. This investigation confirmed the validity of the beneficial-use subcategory for this oilfield discharge.

International Nuclear Information System (INIS)

The Washington Department of Fish and Wildlife (WDFW) has been contracted through the Bonneville Power Administration (BPA) and the Grant County Public Utility District (GCPUD) to perform an evaluation of juvenile fall chinook salmon (Oncorhynchus tshawytscha) stranding on the Hanford Reach. The evaluation, in the fourth year of a multi-year study, has been developed to assess the impacts of water fluctuations from Priest Rapids Dam on rearing juvenile fall chinook salmon, other fishes, and benthic macroinvertebrates of the Hanford Reach. This document provides the results of the 2000 field season.

International Nuclear Information System (INIS)

The Washington Department of Fish and Wildlife (WDFW) has been contracted through the Bonneville Power Administration (BPA) and the Grant County Public Utility District (GCPUD) to perform an evaluation of juvenile fall chinook salmon (Oncorhynchus tshawytscha) stranding on the Hanford Reach. The evaluation, in the second year of a multi-year study, has been developed to assess the impacts of water fluctuations from Priest Rapids Dam on rearing juvenile fall chinook salmon, other fish species, and benthic macroinvertebrates of the Hanford Reach. This document provides the results of the 1998 field season.

Energy Technology Data Exchange (ETDEWEB)

New isotopic age determinations carried out with the rubidium-strontium method on granodioritic basement rocks from the Mecsek Mountains in Southeastern Transdanubia give further support to assumptions on a polyphase development of the Mecsek crystalline. As shown by initial Sr isotopic ratios, the protolith of the granodioritic assemblage of polymetamorphic-anatectic origin must have been strongly basic in its composition. The scatter of individual model ages obtained on total rock samples reflects the polymetamorphic-polytectonized character of the basement, and suggests that following a primary granitization process secondary events might have led to the total or partial recrystallization of the rocks in question. The tectonic development of the basement crystalline as reflected in the isotopic age data closed at about 270+-20 million years ago, with processes causing retrograde changes in the crystalline as a whole but leading to the development of dyke rocks ...

British Library Electronic Table of Contents (United Kingdom)

Eshkaft-e Gavi is a cave located in the southern Zagros Mountains of Iran and is one of the few archaeological sites in the region to preserve both Middle Paleolithic and Upper Paleolithic occupations. Excavation of the site in the 1970s yielded an assemblage of lithic and faunal remains, including ten hominin specimens: a mandibular molar, four cranial fragments, a clavicular diaphysis, the proximal half of a metacarpal, a fragment of os coxa, the proximal diaphysis of a juvenile femur, and a patella. The bones derive from a minimum of four individuals, including two juveniles. Although many of these remains could be Epi-Paleolithic in age, one of the juvenile specimens-the mandibular molar-occurs at the base of the caves Upper Paleolithic sequence. The remains are very fragmentary, but t...

British Library Electronic Table of Contents (United Kingdom)

Here we present a revision of the fossil record of chitons (Mollusca, Polyplacophora) of Late Pleistocene and Holocene marine deposits of Uruguay and discuss their potential for palaeoenvironmental reconstruction. Chitons were recorded as isolated valves in bivalve- and gastropod-rich assemblages. They are represented by the species Chaetopleura angulata (Spengler), C. isabellei (d'Orbigny), C. asperrima (Gould) and Ischnochiton striolatus (Gray). The last two species are recorded for the first time as fossils not only in Uruguay but also in South America. Exclusively recorded for the Late Pleistocene is the warm water species I. striolatus, whose current southern range limit is located in Santa Catarina, Brazil. Higher temperatures than at present are inferred for the Uruguayan coast duri...

International Nuclear Information System (INIS)

The population of the hyporheic interstice and moss cushions by meso- and macroinvertebrates as found at the three measuring points along the Alte Riefensbeek and the Grosse Soese, respectively, in the period from March 1987 to May 1988 is studied and evaluated together with chemical measurements performed between 1987 and 1990. The six measuring points are positioned along an acidification gradient ranging from non-acid to severely acidified. Chemical and biological paramerters are studied with regard to their suitability as indicators of acidification. A model is presented which decribes the influence of abiotic anthropogenic and natural factors on invertebrate species diversity and populations and which can serve as a basis for the calculation of critical deposition burdens. (orig.).

International Nuclear Information System (INIS)

The US Department of the Army, Baltimore District Corps of Engineers, oversees a long-term monitoring study to assess and evaluate effects of the Jennings-Randolph reservoir on biota in the North Branch Potomac River. The reservoir was intended, in part, to mitigate effects of acid mine drainage originating in upstream and headwater area. The present study assessed recovery of benthos and fish in this system, six years after completion of the reservoir. Higher pH and lower iron and sulfate concentrations were observed upstream of the reservoir compared to preimpoundment conditions, suggesting better overall water quality in the upper North Branch. Water quality improved slightly directly downstream of the reservoir. However, the reservoir itself was poorly colonized by macrophytes and benthic organisms, and plankton composition suggested either metal toxicity and/or nutrient limitation. One large tributary to the North Branch and the reservoir (Stony River) was shown to have high (and ...

Energy Technology Data Exchange (ETDEWEB)

The Permian San Andres Formation of late Leonardian-early Guadalupian age is a significant hydrocarbon producer and crops out over a large area in south-central New Mexico. However, since its definition in 1909, the age and depositional environment of this unit have been questioned. In 1971 in Pecos County, Vincent Kelly divided the unit into three members: Rio Bonito, Bonney Canyon, and Fourmile Draw. The lowest member, although named for the Rio Bonito, has a type section designated at Sunset along U.S. Highway 70/380. Two miles east of Sunset, near Riverside, on the Rio Bonito, the Rio Bonito Member is exposed in a long series of roadcuts. Petrographic investigation of these rocks reveals an alternating sequence of high to low-energy intertidal to subtidal facies marked by oolitic and fossiliferous dolocalcarenite interbedded with dolomitic mudstone. The unit has been recrystallized and stylolites are abundant, as is dolomite and nodular mosaic anhydrite. These alternating units ...

International Nuclear Information System (INIS)

One of the initial stages in ecological risk assessments for hazardous waste sites is the screening of contaminants to determine which of them are worthy of further consideration as open-quotes contaminants of potential concern.close quotes This process is termed open-quotes contaminant screening.close quotes It is performed by comparing measured ambient concentrations of chemicals to benchmark concentrations. Currently, no standard benchmark concentrations exist for assessing contaminants in soil with respect to their toxicity to soil- and litter-dwelling invertebrates, including earthworms, other micro- and macroinvertebrates, or heterotrophic bacteria and fungi. This report presents a standard method for deriving benchmarks for this purpose, sets of data concerning effects of chemicals in soil on invertebrates and soil microbial processes, and benchmarks for chemicals potentially associated with United States Department of Energy sites. In addition, literature ...

International Nuclear Information System (INIS)

Sediment treatment and sediment storage may alter sediment toxicity, and consequently biotic response. Purpose of our study was to combine these three aspects (treatment-toxicity-biotic response) in one integrated approach. We used Acid Volatile Sulfide (AVS) concentrations as a proxy of the disturbance of the sediment. AVS and Simultaneously Extracted Metal (SEM) concentrations were compared to bioassay responses with the freshwater benthic macroinvertebrate Asellus aquaticus. Storage conditions and sediment treatment affected AVS but not SEM levels. AVS can be used as a proxy for sediment disturbance. The best way to pretreat the sediment for use in a bioassay in order to maintain initial AVS conditions was to sample the sediment with an Ekman grab, immediately store it in a jar without headspace, and freeze it as soon as possible. In a survey using seven different sediments, bioassay responses of A. aquaticus were correlated with SEM and AVS characteristics. - ...

International Nuclear Information System (INIS)

Water quality of the Citarum River and the Jatiluhur Reservoir in Indonesia was evaluated using C-14 radioisotope. A close relationship between the abiotic (physical and chemical) and the biotic (algal growth potential, primary productivity, chlorophylla and diversity index of planktonic and benthic macroinvertebrate) parameters was obtained. Algal growth potential to abiotic parameters relationship has the highest correlation coefficient and can be used as a pollution indicator. The other biotic parameters do not show clear relationship with the abiotic parameters. The Citarum water quality is the lowest in those locations which receive human and industrial waste from Bandung and its environment. This water cannot be used for drinking purposes and fishery. The water quality in other locations of the river, however, meets the criteria for agriculture. Agricultural waste does not show any drastic effect on the water quality profile due to non-polluted ...

International Nuclear Information System (INIS)

Macrofouling of cooling-water systems is one of the more significant and costly problems encountered in the nuclear power industry. Both marine and freshwater macroinvertebrates can be responsible for losses in plant availability because of plugged intakes and heat transfer equipment. There is a greater diversity of macrofouling organisms in marine waters than in fresh waters. Marine macrofouling organisms include barnacles, mollusks, bryozoans, and hydroids. Barnacles are crustaceans with feathery appendages, which allow them to attach to a variety of surfaces. They are a major cause of severe macrofouling because they can remain attached even after death. The major freshwater macrofouling organisms include the Asiatic Clam (Corbicula fluminea) and the newest freshwater macrofouler, the Zebra Mussel (Dreissena polymorpha). The introduction of the Zebra Mussel into the Great Lakes has created economic and ecological problems that will not easily be solved. The ...

International Nuclear Information System (INIS)

Increasing salinity has the potential to affect freshwater organisms. Yet sub-lethal effects of salinity on macroinvertebrates are poorly understood. Growth and development of Ischnura heterosticta (Odonata: Coenagrionidae) was experimentally shown to be faster in 5-20 mS/cm than 0.1-1 mS/cm, while in 35 mS/cm all individuals died. In 30 mS/cm about half died and growth was similar to the 0.1 mS/cm treatment. The salinity-growth relationship cannot be explained indirectly, that is salinity affecting the survival of their prey. Tissue content and concentration of Ca, Mg, Na and K in emerged adults showed no evidence of deficiencies at low salinity. Heart beat rate was similar across treatments, except at 35 mS/cm, where it was slower. Respiration and feeding were similar at 0.1, 10 and 30 mS/cm. While there are similarities in I. heterosticta and other species' salinity response, there are differences and studies on more species are urgently needed. - This species ...

International Nuclear Information System (INIS)

It has been acknowledged that river morphology and hydrology have been intensively altered due to the anthropic demands in floodplain land use and management, flood protection, promotion of navigability or energy production. Rivers were transformed in water highways, having lost contact with their surrounding floodplain as well as the plethora of ecological processes and occupants once thriving in these ecotonal zones. The identification of this emerging threat of morphological and hydrological alteration on ecological integrity adds further complexity in the exploitation of hydrosystem resources. These resources are heavily coveted and guarded by different lobbies each having strategic views on future project development. Stakeholders may want to promote hydro-electricity, ecologists a natural reserve, communes may wish to have an increased flood protection and leisure promoters a nautical center. As a result, the proposition of a river development project is certain to face ...

International Nuclear Information System (INIS)

Distinguishing between effects of natural and anthropogenic environmental factors on ecosystems is a fundamental problem in environmental science. In river systems the longitudinal gradient of environmental factors is one of the most relevant sources of dissimilarity between communities that could be confounded with anthropogenic disturbances. To test the hypothesis that in macroinvertebrate communities the distribution of species' sensitivity to organic toxicants is independent of natural longitudinal factors, but depends on contamination with organic toxicants, we analysed the relationship between community sensitivity SPEARorganic (average community sensitivity to organic toxicants) and natural and anthropogenic environmental factors in a large-scale river system, from alpine streams to a lowland river. The results show that SPEARorganic is largely independent of natural longitudinal factors, but strongly dependent on contamination with organic toxicants ...

Science.gov (United States)

A post-accident-heat-removal structural effects analysis for the steel liner in the FFTF concrete containment structure is presented. (JWR)

Energy Technology Data Exchange (ETDEWEB)

Late plagiogranite bodies in the Semail ophiolite have been previously suggested to represent late stage fractionates within an episodic spreading center magma chamber or the roots of seamount chains. Field and lab observations suggest that these late silicic magma chambers represent zones of repeated injection by dikes of intermediate to mafic composition. Multiple generations of intrusion, partial resorption and reintrusion are preserved in the plagiogranite as 1) relict phantom xenoliths, 2) angular xenoliths with quartz-rich margins, 3) deformed fine-grained dikes with distinct chilled margins, and 4) planes of rectangular blocks with cuspate margins or ellipsoids of similar fine grained mafic materials. The blocks and ellipsoids are actually dismembered mafic dikes that chilled by intruding a cooler silicic liquid and were either thermally fractured or pinched out. All of the dikes are hydrothermally altered to assemblages including amph., qtz., epi., preh., ...

Energy Technology Data Exchange (ETDEWEB)

Three algal bioassay experiments were conducted from March 1992 through September 1993 in an area of Lake Mead that has experienced problems associated with severe nutrient enrichment. The first experiment determined the effects of elevated CO2 (700 ppm) (2xCO2), vs ambient CO2 on the natural algal assemblage without nutrient enrichment. The second experiment determined the effects of 2xCO2 on nutrient enriched bioassays and if nutrients were limiting. The third experiment examined elevated temperatures and 2xCO2. Nested climate models were used to predict changes in water temperatures and thermocline development in Las Vegas Bay. The lake model predicted an increase in mean water temperatures of 1.8 deg under a 2xCO2 scenario. A thermocline definition of 1 deg. C change per 2-m depth was applied to water temperatures developed by a lake model coupled to nested general circulation and regional-scale atmospheric models in 3-year simulations of the current and ...

Science.gov (United States)

Another difference lies in the speed of star evolution. 2. Computation of Stellar Structure and Their Evolution. The structure of stars at certain instants ...

KoreaScience (Korea)

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International Nuclear Information System (INIS)

The objectives of this research were (1) to analyze the transfers of 137Cs and 60Co in a retention pond, with emphasis on aquatic insects and (2) to determine if detectable concentrations of these radionuclides are exported by emerging aquatic insects. We analyzed the radionuclide concentrations in the following components: water solution, bottom sediments, suspended particulate matter, plankton, floating mats of filamentous algae, benthic macroinvertebrates, and emerging aquatic insects. Samples were collected quarterly from June 1981 to April 1982. The lowest concentrations (in picocuries per milliliter) occurred in solution (range: 1.4 X 10(2) to 3.2 X 10(2) for 137Cs and 8.1 X 10(-1) to 2.2 X 10(0) for 60Co). The highest concentrations (in picocuries per gram dry weight) occurred in the sediments (range: 1.5 X 10(4) to 1.1 X 10(8) for 137Cs and 1.0 X 10(2) to 4.3 X 10(6) for 60Co). The primary producers and aquatic insect consumers had concentrations of both ...

International Nuclear Information System (INIS)

At two locations in southern Lake Huron (U.S.A.), twelve 35.5-cm diameter cores of fine-grained sediments were taken for comparison of the vertical distribution of "2"1"0Pb and fallout "1"3"7Cs with the distribution of benthic macroinvertebrates, mainly oligochaete worms (Tubificidae) and the amphipod, Pontoporeia affinis. Locations were selected on the basis of "2"1"0Pb distributions measured a year earlier which indicated contrasting depths of mixing of surface sediments. At one location the activity of "2"1"0Pb is uniform down to about 6 cm and 95% of total invertebrates occur within this zone; at the other location the zone of constant activity is only 3 cm deep but 90% of the invertebrates occur within it. Comparison of published tubificid defecation rates with sediment accumulation rates based on "2"1"0Pb shows that oligochaetes alone can account for mixing in one case while the effects of amphipods may be required in the case of shallower mixing. If mixing ...

International Nuclear Information System (INIS)

Changes in physical and chemical characteristics of aquatic habitats made to reduce or eliminate ecological risks can sometimes have unforeseen consequences. Environmental management activities on the U.S. Dept. of Energy reservation in Oak Ridge, Tennessee,have succeeded in improving water quality in streams impacted by discharges fi-om industrial facilities and waste disposal sites. The diversity and abundance of pollution-sensitive components of the benthic macroinvertebrate communities of three streams improved after new waste treatment systems or remedial actions reduced inputs of various toxic chemicals. Two of the streams were known to be mercury-contaminated from historical spills and waste disposal practices. Waterborne mercury concentrations in the third were typical of uncontaminated systems. In each case, concentrations of mercury in fish, or the apparent biological availability of mercury increased over the period during which ecological metrics ...

International Nuclear Information System (INIS)

#gamma# spectroscopy methods have been applied to determine the effects of two freshwater benthic macroinvertebrates, on reworking of sediments and the transfer of solutes across the sediment-water interface. Natural lake sediments and overlying water were contained in temperature-regulated rectangular plastic cells. After addition of Stylodrilus (oligochaete worms) and Pontoporeia (crustacean amphipods) to these microcosms, the vertical distribution of Cs-137 (a tracer of particle transport) and Na-22 (a tracer of solute transport) were determined. In cells with Stylodrilus, the Cs-137 layer moved downward at a rate that decreased exponentially with time. In cells with Pontoporeia, Cs-137 activity was smeared downward in time owing to eddy diffusive mixing of sediments over a small range (1-2 cm). In cells without worms, the veneer of Cs active material remained at the interface while the penetration of Na-22 into sediments was consistent with diffusion in free ...

Energy Technology Data Exchange (ETDEWEB)

Diverse and productive wetlands have resulted from coal mining in the midwest. The trend from surface to underground mining has increased the potential for subsidence. Planned subsidence of longwall mining areas provides increased opportunities for wetland habitat establishment. Planned subsidence over a 180 meter (590 foot) deep longwall mine in southern Illinois during 1984 to 1986 produced three subsidence wetlands totaling 15 hectares (38 acres). The resulting palustrine emergent wetlands enhanced habitat diversity within the surrounding palustrine forested unsubsided area. Habitat assessments and evaluations of avian utilization of the subsidence wetlands were conducted during February 1990 through October 1991. Avian utilization was greatest within the subsided wetlands. Fifty-three bird species representing seven foraging guilds utilized the subsidence wetlands. Wading/fishing, dabbling waterfowl, and insectivorous avian guilds dominated the subsidence wetlands. The subsidence ...

UK PubMed Central (United Kingdom)

Studies of the antigenic structure of the polysaccharide component of gonococcal lipopolysaccaride (LPS) indicated that the non-serogroup antigen structure is antigenically heterogeneous. Immunodiffusion...Full Text Available

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No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

KoreaScience (Korea)

Full Text Available

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No abstract prepared.

International Science & Technology Center (ISTC)

Fundamental Research of Materials Structure and Properties Changes Resulted from Irradiation by Means of Complex of Modern Physical Methods

Energy Technology Data Exchange (ETDEWEB)

Techniques for studying nuclear structure are reviewed. Examples are given of charge density determinations by electron and proton inelastic scattering. (AIP)

CERN Document Server

Full-Potential Electronic Structure Method

Science.gov (United States)

... The program generates conceptual layouts of wing structural components and creates a beam finite element model of the wing structure (Figure 6 ...

International Nuclear Information System (INIS)

The objective of this study is to comprehend the basic structural characteristics of box shaped mixed structures proposed for a future nuclear reactor building structure. Specimens of reinforced concrete precast panel walls of the mixed structures were prepared using ultrahigh strength materials. Two bending shear tests were conducted with a parameter of the quantity of reinforcement bars. The results include: (1) Relationship of shear stress and the angle of the structure, and (2) Failure mode. (author)

International Nuclear Information System (INIS)

The phenomenological description of the giant magnetoresistance effect as well as discussion of the requirements which must be fulfilled in giant magnetoresistance thin film structures are given in the first part of our review. In the second part the magnetization reversal and giant magnetoresistance effect of antiferromagnetically coupled multilayers, spin Valve and pseudo-spin valve thin film structures are explained. For these structures we also discuss the influence of the structure defects such as surface roughness and pinholes on the giant magnetoresistance effect. (author)

Energy Technology Data Exchange (ETDEWEB)

A novel CFD/structural analysis was performed to predict functionality of a cross parachute under loadings near the structural limits of the parachute. The determination of parachute functionality was based on the computed structural integrity of the canopy and suspension lines. In addition to the standard aerodynamic pressure loading on the canopy, the structural analysis considered the reduction in fabric strength due to the computed aerodynamic heating. The intent was to illustrate the feasibility of such an analysis with the commercially available software PATRAN.

International Nuclear Information System (INIS)

It is shown that the available data on x, Q"2, and A dependence of nuclear structure functions and for their ratios (EMS effect) can be described in terms of the flucton model with rescaling of parton distributions in nuclei. The x, Q"2 and A dependence of nuclear structure functions in the cumulative range (x >1) is predicted.

UK PubMed Central (United Kingdom)

Emphasis was put on the comparative quantitative structure-activity approaches to the exploration of action mechanisms of structurally different classes of compounds showing the same type of activity...Full Text Available

UK PubMed Central (United Kingdom)

AbstractX-ray diffraction analysis of pressure-induced structural changes in the Aequorea yellow fluorescent protein Citrine reveals the structural basis for the continuous...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundStructured noncoding RNAs perform many functions that are essential for protein synthesis, RNA processing, and gene regulation. Structured RNAs can be detected by comparative...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

The present paper considers the evaluation of timber structures with the focus on robustness due to connection ductility. The robustness analysis is based on the structural reliability framework applied to a simplified mechanical system. The structural timber system is depicted as a parallel system. An evaluation method of the ductile behaviour is introduced. For different ductile behaviours, the system reliability is estimated based on Monte Carlo simulation. A correlation between the strength of the structural elements is introduced. The results indicate that the reliability of a structural timber system can be significantly increased due to the ductile behavior.

British Library Electronic Table of Contents (United Kingdom)

Major similarities between robustness assessment and seismic design exist, and significant information can be brought from seismic design to robustness design. As will be discussed, although some methods and limitations considered in seismic design can improve robustness, the capacity of the structure to sustain limited damage without disproportionate effects is significantly more complex. In fact, seismic design can either improve or reduce the resistance of structures to unforeseeable events, depending on the structural type, triggering event, structural material, among others. Based on a case study, the influence of redundancy and ductility on the seismic behavior and robustness of a long-span timber structure is assessed.

UK PubMed Central (United Kingdom)

This paper examines theoretically the effects that restraints on the tertiary structure of a superhelical DNA domain exert on the energetics of linking and the onset of conformational transitions. The...Full Text Available

Science.gov (United States)

The synthesis and structural characterization of a novel In(III) complex is described. The reaction

International Nuclear Information System (INIS)

1974. 20 p. United States Anon. American Society of Mechanical

UK PubMed Central (United Kingdom)

Structural analysis of an acetylcholine receptor from Torpedo californica leads to a three-dimensional model in which a "monomeric" receptor is shown to contain subunits arranged around a central ionophoretic...Full Text Available

Science.gov (United States)

... Composite sandwich panels with fiber reinforced plastic (FRP) faces and low 3 density foam cores are fast becoming the structural material of ...

International Nuclear Information System (INIS)

In the past decade, considerable progress has been made on reducing the seismic response of structures through seismic isolation. Application of seismic-isolation techniques to nuclear power facilities is currently being investigated. This paper presents an analysis of the effect of long period motions on a seismic-isolated nuclear structure. Preliminary analysis indicates that long-period earthquake motions increase structural accelerations and relative displacements between the upper and lower mats. Relative displacement between the mats can be represented by spectral displacement at the frequency of the structure, and can be effectively reduced by increasing viscous damping in the isolator. The isolated structure behaves as a system with one degree of freedom. Future analysis of seismic effects on seismic-isolated structures should include the linear and ...

Science.gov (United States)

Development efforts have been undertaken to improve the processing and structural efficiencies of

International Nuclear Information System (INIS)

... functions intermediate structure isobaric analogs level widths mev range

Science.gov (United States)

star evolution, globular cluster structure and evolution, massive stars, supernova remnants, reflection nebulae, interstellar dust, structure of the ISM, ...

Science.gov (United States)

... CI Appendix D: Conference Attendees ..... D1 Appendix E: Structural Steel Connection Design on Federal Projects ..... El iv ...

CERN Document Server

A conceptual design for the module design and disc support structure for the ATLAS forward SCT tracker

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

Not Available

KoreaScience (Korea)

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International Nuclear Information System (INIS)

Structural instabilities are now being found in many high-temperature superconductors. Compounds with the A-15 (#beta#-W) structure comprise the most important group of these materials, and their properties have been extensively studied for over 15 years. A review is given of some of these results, particularly those relating to the elastic behavior. The empirical relation of the structural instability and the anharmonicity to the high superconducting transition temperature is discussed.

Science.gov (United States)

There are about fifty SET domain protein methyltransferases (PMTs) in the human genome, that transfer a methyl group from S-adenosyl-L-methionine (SAM) to substrate lysines on histone tails or other peptides. A number of structures in complex with cofactor, substrate, or inhibitors revealed the mechanisms of substrate recognition, methylation state specificity, and chemical inhibition. Based on these structures, we review the structural chemistry of SET domain PMTs, and propose general concepts towards the development of selective inhibitors.

KoreaScience (Korea)

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KoreaScience (Korea)

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Science.gov (United States)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

KoreaScience (Korea)

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International Nuclear Information System (INIS)

... administrative procedures developing countries economic development nuclear

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

A method is described for increasing pressure in geologic oil-bearing structures by gas production due to microbial activity. There is added to an oil-bearing structure an anaerobic micro-organism (Methanobacterium termoautotroficum), a culture medium and formic acid. The formic acid is converted to carbon dioxide and methane gases resulting in increased pressure in the structures. Methanobacterium termoautotroficum cannot split formic acid into CO/sub 2/ and H/sub 2/ but it can produce methane from these 2 gases. 4 claims.

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

Germanium coordination compounds (GCC) with oxiethilidendyphosphonic acid (Ge-Oedph) film structures electrophysical, optical, structural and adsorptive properties investigation results are represented. This structure concerns to a new perspective class of functional materials. The mechanism GCC films electric conductivity is investigated and explained. GCC possible application fields are specified.

KoreaScience (Korea)

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Science.gov (United States)

Not Available

KoreaScience (Korea)

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KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Wastenet

animation The structure of the creative industries is changing Previously there were small numbers of producers and a

Science.gov (United States)

... 4 Joint Committee on Atomic Energy as a Model . . . . . ... Joint Committee on Atomic Energy as a Model ...

International Science & Technology Center (ISTC)

Development of Ceramic Composite Materials and Structural Elements for High-Temperature Nuclear Reactors

Science.gov (United States)

Language: English ...

Science.gov (United States)

The integrity and safety of beam-like structures are dependent in part on their boundary conditions which can vary with time due to damage or aging. Structural health monitoring of such structures should therefore include attention to boundary conditions. Where the boundary conditions can be represented by a lumped spring then the identification of associated stiffness parameter values may be a means to quantifying the integrity of the support. This paper investigates such a method for identifying the equivalent translational and rotational stiffness of a constrained tapered beam-like structure. An analytical model of a beam of tapered width and thickness is adopted as a simplified representation of a tower-like structure. The model is used to explore in what scenarios natural frequencies and/or nodal points might be sufficiently sensitive to changes in support conditions to be ...

International Nuclear Information System (INIS)

A series of Model Tests of Embedment Effect on Reactor Buildings has been carried out by the Nuclear Power Engineering Corporation (NUPEC), under the sponsorship of the Ministry of International Trade and Industry (MITI) of Japan. Sinusoidal forced vibration tests were carried out on three types of large-scale models to study the embedment effect on dynamic soil-structure interaction. The differences in the resonance curves and the impedance functions were discussed in relation to the vibration characteristics of the respective structures. The embedment effects on the structural responses vary according to the stiffness of the structure. The responses of the structures can be evaluated by the Axisymmetric FEM analyses. (author)

International Nuclear Information System (INIS)

A theoretical study of structural and electronic properties of GeC, SnC and GeSn is presented using the full potential linearized augmented plane wave method. In this approach, the generalized gradient approximation was used for the exchange-correlation potential. Results are given for lattice constant, bulk modulus and its pressure derivative in both zinc-blende and rocksalt structures. Band structure, density of states and band gap pressure coefficients in zinc-blende structure are also given. The results are compared with previous calculations and with experimental measurements.

Energy Technology Data Exchange (ETDEWEB)

The Green River Basin is a northwest-southeast elongate structural feature located in southwestern Wyoming. Bounded by three basement uplifts, this complex mountain front basin possesses tremendous gas reserves. Production has been limited to a few structures, such as the Pinedale Anticline, because of the great depth of the basin. The Pinedale Anticline is an elongate structure that parallels the front of the Wind River Thrust. Earlier research has suggested that the anticline is not related to basement, but rather is associated with a foreland detachment structure. A new, high-resolution aeromagnetic survey has been modelled in detail and the results indicate that the Pinedale Anticline may actually be a basement related structure. Profile modelling normal to the anticline from the LaBarge Platform to the Wind River Mountains suggests that not only is Pinedale Field situated on a ...

Science.gov (United States)

Reciprocity is one of the defining features of social exchange and social life, yet exchange theorists have tended to take it for granted. Drawing on work from a decade-long theoretical research program, I argue that reciprocity is structured and variable across different forms of exchange, that these variations in the structure of reciprocity have profound effects on the emergence of integrative bonds of trust and solidarity, and that these effects are explained and mediated by a set of risk- and conflict-based processes. I discuss the consequences of this work for organizational theories of embeddedness and the production of social capital through network ties. Finally, I ask how the structure of networks and the structure of reciprocity are related to one another, and explore possible implications of the structure of reciprocity for exchange theorists' assumptions about actor ...

British Library Electronic Table of Contents (United Kingdom)

Summary: Protein features are often displayed along the linear sequence of amino acids that make up that protein, but in reality these features occupy a position in the folded proteins 3D space. Mapping sequence features to known or predicted protein structures is useful when trying to deduce the function of those features and when evaluating sequence or structural predictions. To facilitate this goal, we developed PDBpaint, a simple tool that displays protein sequence features gathered from bioinformatics resources on top of protein structures, which are displayed in an interactive window (using the Jmol Java viewer). PDBpaint can be used either with existing protein structures or with novel structures provided by the user. The current version of PDBpaint allows the visualization of annot...

Energy Technology Data Exchange (ETDEWEB)

Study of glacial geology, stream drainage, bedrock topography, and subsurface structure maps in Isabella, Midland, Arenac, Gladwin, Clare, Ogemaw, Iosco, Mecosta, and Montcalm counties in Michigan revealed distinct correlations between patterns and types of glacial deposits and subsurface structures. Anticlinal structures associated with the Mt. Pleasant, North Buckeye, and South Buckeye, Hamilton, Deep River, Clayton, Logan, Six Lakes, and West Branch oil and gas fields occur along areas where northeast-trending glacial moraines and truncated, attenuated, or deviated. Furthermore, these anticlinal structures are associated with lacustrine sands and gravels and glacial outwash deposits nearly surrounded by glacial tills or lacustrine sands and clays. All of the anticlinal structures are associated with bedrock topography highs and alignment of streams parallel to the trends of the ...

UK PubMed Central (United Kingdom)

AbstractThe structural integrity of striated muscle is determined by extra-sarcomere cytoskeleton that includes structures that connect the Z-disks and M-bands of a sarcomere to sarcomeres...Full Text Available

UK PubMed Central (United Kingdom)

The structure of the skin in the epauletted fruit bat (Epomophorus wahlbergi) wing and body trunk was studied with a view to understanding possible adaptations for gas metabolism and...Full Text Available

UK PubMed Central (United Kingdom)

X-ray diffuse scattering was measured from oriented stacks and unilamellar vesicles of dioleoylphosphatidylcholine lipid bilayers to obtain the temperature dependence of the structure and of the material...Full Text Available

UK PubMed Central (United Kingdom)

CBP and its paralog p300 are histone acetyl transferases that regulate gene expression by interacting with multiple transcription factors via specialized domains. The structure...Full Text Available

UK PubMed Central (United Kingdom)

SUMMARYThe cytolytic activity of natural killer (NK) cells is regulated by inhibitory receptors that detect the absence of self molecules on target cells. Structural studies of...Full Text Available

UK PubMed Central (United Kingdom)

Six related Staphylococcus phages spontaneously produced various abnormal head and tail structures: (i) giant capsids which were tailed and apparently contained nucleic acid; (ii) regular and irregular...Full Text Available

UK PubMed Central (United Kingdom)

High resolution structural elucidation of macromolecular structure by solid-state nuclear magnetic resonance requires the preparation of uniformly aligned samples that are isotopically labeled. In...Full Text Available

UK PubMed Central (United Kingdom)

A protein evolution strategy is described by which double-stranded DNA fragments encoding defined E. coli protein secondary structural elements (α-helices, β-strands...Full Text Available

UK PubMed Central (United Kingdom)

Motivated by the observation that a retinal fundus image may contain some unique geometric structures within its vascular trees which can be utilized for feature matching, in this paper, we proposed...Full Text Available

UK PubMed Central (United Kingdom)

The presence of albumin structures with the capacity to bind to a surface receptor in group C and G streptococci was studied in serum samples from 45 mammalian species representing 15 different orders,...Full Text Available

UK PubMed Central (United Kingdom)

The T-loop motif is an important recurrent RNA structural building block consisting of a U-turn sub-motif and a UA trans Watson–Crick/Hoogsteen base pair. In the presence of...Full Text Available

UK PubMed Central (United Kingdom)

This neutron reflectometry study evaluates the structures resulting from different methods of preparing polymer-cushioned lipid bilayers. Four different techniques to deposit a dimyristoylphosphatidylcholine...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundThe exploitation of information extraction (IE), a technology aiming to provide instances of structured representations from free-form text, has been rapidly growing within...Full Text Available

Science.gov (United States)

Cadmium telluride single crystals were subjected to multiple-energy boron ion implants with total doses up to 1.5 x 10 sq cm. Various diagnostic techniques were used to assess the structural and electronic properties of these crystals in their as-implante...

International Nuclear Information System (INIS)

The formation of porous structures of nanometre size (nanoporous structures) on germanium (Ge) surfaces by focused ion beam (FIB) irradiations was investigated using various FIB conditions such as ion species, irradiation energies, total fluences, fluence rates, and incident angles. FIB-irradiated regions were observed using a scanning electron microscope and an atomic force microscope. It is found that, using a focused Ga ion beam (Ga FIB) at an energy of 100 keV, the irradiated Ge surface swelled up to ion fluence of 2 x 10"1"7 cm"-"2 with nanoporous structures and then was etched for larger fluences. The shape of swollen nanoporous structures depended on the fluence rate and the incident angle of the Ga FIB. However, such porous structures were observed neither for low-energy (15-30 keV) FIB irradiations using Si and Au ions nor for high-energy (200 keV), heavy ion (Au) ...

Energy Technology Data Exchange (ETDEWEB)

Electricity markets in the United States are undergoing unprecedented structural changes as a result of the confluence of regulatory, competitive, and technological forces. This paper introduces these structural changes and forces and discuss the implications, markets and commercialization scenarios for emerging fuel cells in evolving US electricity markets.

UK PubMed Central (United Kingdom)

Despite prolonged scientific efforts to unravel the hydration structures of ions in water, many open questions remain, in particular concerning the existences and structures of ion clusters in 1∶1...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

This paper describes the investigation into the influence of coke pore structure on the formation of nitrogen oxides and carbon monoxide during the combustion of coke. Two samples of coke were compared; pulverized coke and lump coke.

Energy Technology Data Exchange (ETDEWEB)

The possibility of rapid heat treatment (RHT) application to titanium castings has been studied. It was shown that such treatment provides a significant improvement of intragrain structure and mechanical properties of cast ({alpha}+{beta})-titanium alloys. ((orig.))

International Nuclear Information System (INIS)

This standard provides the general requirements used in the design, construction, testing, and commissioning of concrete containment structures for CANDU nuclear power plants designated as class containment and is directed to the owners, designers, manufacturers, fabricators, and constructors of the concrete components and parts.

Science.gov (United States)

This report documents the collaborative effort between the United States and Canada to investigate the impact of process-induced defects on strength and stiffness under static and fatigue loading and for low-cost composite aircraft structures, in particul...

UK PubMed Central (United Kingdom)

The protein databank (PDB) contains high quality structural data for computational structural biology investigations. We have earlier described a fast tool (the decomp_pdb tool) for identifying and...Full Text Available

Science.gov (United States)

The mechanical characteristics of semicrystalline materials are related to the proportion, size and structure of the crystalline phase. Studying isothermal crystallization is the first stage in determining what relations exist between structure and charac...

Science.gov (United States)

... of new construction materials; and the behavior of infrastructure materials and structural ... polymers, reinforcing materials, wood and biodegradable structural materials; scale effects from ...

Energy Technology Data Exchange (ETDEWEB)

Authors already reported the integrated system so called SODAS (System Of Design and Assembling for Shipbuilding) which was based on product model concept. And products in shipbuilding industry today are not limited to ship structures alone. Therefore, it is desirable that a more global product model which can describe another products such as offshore structures should be considered. In this paper, a product model of offshore structures is discussed. Compared with the case of ship structures, the distinctive feature in the design stage of offshore structures lies in the initial design stage. Thus in this paper, some of the new model in initial design stage are introduced. Some of them are `Function Element Model` which expresses functional concept by designers. In the other design stage, product information such as `Room` and `Part` which were already introduced in SODAS are used ...

UK PubMed Central (United Kingdom)

BackgroundThe fast growing Protein Data Bank contains the three-dimensional description of more than 45000 protein- and nucleic-acid structures today. The large majority of the data...Full Text Available

Science.gov (United States)

A high degree of structural perfection is an essential requirement for CdTe crystals used as substrates for the epitaxial growth of CdHgTe alloys. Here, a method for the evaluation of the structural perfection of CdTe crystals is proposed which is based on X-ray diffraction measurements using both two-crystal and three-crystal diffractometers (differential version). The method makes it possible to obtain more information on structural perfection both at the crystal surface and within the crystal body.

International Nuclear Information System (INIS)

... 1343-3563 v. 57(1) SPECIFIC NUCLEAR REACTORS AND ASSOCIATED

International Nuclear Information System (INIS)

Using an ab initio pseudopotential method within a generalized gradient approximation of the density functional theory, the structural, electronic, and phonon properties of SrS in the B1 (NaCl) and B2 (CsCl) structures have been studied. The calculated lattice constants, static bulk modulus, and first-order pressure derivative of the bulk modulus are reported for both the B1 and B2 structures and compared with previous experimental and theoretical calculations. Electronic band structures and densities of states have been derived for SrS. Subsequently, a linear-response approach to the density functional theory is used to derive the phonon frequencies and densities of states.

International Nuclear Information System (INIS)

... states gamma radiation mev range 01-10 photonuclear reactions polarization

British Library Electronic Table of Contents (United Kingdom)

During the design process, designers have to define the structure of their product while considering its functional definition. This design phase remains little assisted for designers. In addition, as numerous options can be considered for the end of life of a product (reuse, remanufacturing, recycling,) it becomes more difficult to obtain a compromise concerning the final structure of the product. In this paper, we will show how the use of virtual reality helps designers to transform the functional definition of the product into the design of its structure, during the conceptual design phase. The developed example will concern the design of a bathroom scale.

International Nuclear Information System (INIS)

... Union (INTAS), Brussels (Belgium) Science and Technology Center in Unkraine,

Science.gov (United States)

... Keywords: Ferrocement; Floating concrete structures; Ships; Barges; and Offshore platforms. Descriptors : *REINFORCED ...

International Nuclear Information System (INIS)

1975. USSR Zabrodskij, VA Nedavnij, OI INIS-mf--3677. Available from

International Nuclear Information System (INIS)

... S. Perfilov, SV Institute of Nuclear Fusion, RRC Kurchatov Institute, Moscow

Science.gov (United States)

Not Available

British Library Electronic Table of Contents (United Kingdom)

The natural clayey soils are usually structural and unsaturated, which makes their mechanical properties quite different from the remolded saturated soils. A structural constitutive model is proposed to simulate the bonding-breakage micro-mechanism. In this model, the unsaturated soil element is divided into a cementation element and a friction element according to the binary medium theory, and the stress-strain coordination for these two elements is obtained. The cementation element is regarded as elastic, whereas the friction element is regarded as elastoplastic which can be described with the Gallipoli?s model. The theoretical formulation is verified with the comparative experiments of isotropic compressions on the saturated and unsaturated structural soils. Parametric analyses of the e...

Science.gov (United States)

... core section of the composite sandwich panels (Figure 5). Table 6 shows the properties that buckled as well as their initial ...

Energy Technology Data Exchange (ETDEWEB)

A shock absorber mechanism and method for use on the leg structure of a jack-up offshore drilling rig is described. It is mounted on the bottom of each existing leg of a drilling rig and comprises a pointed piston member which is positioned on the bottom of the leg structure and projects downwards through the can/footing of the rig leg. The piston member is held in place by a resilient tension member which is designed to absorb shock forces during vertical/axial impact of the leg structure when contact is made with the ocean floor. (author).

Energy Technology Data Exchange (ETDEWEB)

The paper describes an experimental investigation involving pore structure of blended gypsum binder. The pore structure was investigated by using mercury porosimeter. A relationship between structure and mechanical properties has been established. It has been found that the principal factor of porosity governs the development of structure and strength of the blended gypsum binder. The pore size distribution was characterized by a reduction in the volume of the pores whose diameters are larger than 500 {angstrom} and an increase in the volume of those smaller diameters. An interpretation of the development in strength vis-a-vis porosity of the blended gypsum binder is presented.

International Nuclear Information System (INIS)

This manual is a collection of various notes, memoranda and instructions on procedures for the evaluation of data in the Evaluated Nuclear Structure Data File (ENSDF). They were distributed at different times over the past few years to the evaluators of nuclear structure data and some of them were not readily avaialble. Hence, they have been collected in this manual for ease of reference by the evaluators of the international Nuclear Structure and Decay Data (NSDD) network contribute mass-chains to the ENSDF. Some new articles were written specifically for this manual and others are reivsions of earlier versions.

International Nuclear Information System (INIS)

This paper presents the objective, scope, and status of the U.S. Department of Energy's Materials and Structures Program to develop a data base on mechanical properties of structural materials for out-of-core structures and components for LMFBRs. Information on the development of a reference data base on materials for the reactor system, reactor enclosure system, primary heat transport system, intermediate heat transport system, and steam generator system is included. In addition, the development of the data and analyses to account for the effects of temperature and stress, as well as water/steam, sodium, and radiation environments, is described. Plans for the development of alternative materials for future out-of-core applications are presented. (author).

Science.gov (United States)

System). From collecting terabytes of video footage to tracking the movements of the submarines, this software is essential to the science team as they explore unique structures on...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

... structure along an elevational gradient in Hawaiian honeycreepers reveals contrasting evolutionary responses to avian malaria. BMC Evolutionary Biology 8: ... ...

International Nuclear Information System (INIS)

The methods of optical and transmission electron microscopy were used to study the influence of different programmes of hot deformation on the structure formation of (#alpha#+#beta#) titanium alloy VT9. The #beta# alloy VT-15 was studied at the same time in order to simulate the dislocation structure generated in the process of hot deformation. During the hot deformation of two-phase titanium alloys in both #beta# and (#alpha#+#beta#) ranges there is found to be an optimum range of deformation in which a homogeneous, polygonized structure is formed.

Science.gov (United States)

... laser structure. However, still the greater part (60%) of emitted photons is a result of a spontaneous radiation process. In ...

Science.gov (United States)

Group for Aerospace Research and Development (AGARD) symposium and continue to ...... of vertical structures and flow separation within the tip, platform, ...

Science.gov (United States)

12], the Predictive Capability Maturity Model (PCMM) [ref. 13], the Uncertainty Structure scale [ref. 11], and the Simulation Readiness Level (SRL) scale ...

Science.gov (United States)

... gao. 1993. Structural Matching of Parallel Texts. In ACL 1993 A. Meyers, R. Yangarber, and R. Grishman. 1996. Alignment ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

A new high capacity anode composite based on mesoporous silicon is proposed. By virtue of a structure that resembles a pseudo one-dimensional phase, ...

Energy Technology Data Exchange (ETDEWEB)

The electronic structure of the C15, or cubic-Laves-phase material, UAl/sub 2/ has been calculated using the linearized relativistic augmented-plane-wave method. The anomalous behavior of the electrical resistivity, specific heat, and magnetic susceptibility can be explained by the fine structure of the density of states near the Fermi energy alone, without the necessity of the introduction of drastic spin fluctuations or many-body effects.

Energy Technology Data Exchange (ETDEWEB)

It is shown that the available experimental data on the x, Q/sup 2/, and A dependences of the structure functions of nuclei and their ratios (the EMC effect) can be described by the flucton model with rescaling of the parton distributions in nuclei. The x, Q/sup 2/, and A dependence of the nuclear structure functions in the cumulative region (x>1) is predicted.

Energy Technology Data Exchange (ETDEWEB)

We review the physics of structure functions at low Q{sup 2}, focusing on the phenomenon of quark-hadron duality and the resonance-scaling transition, both phenomenologically and in the context of quark models. We also present a new implementation of target mass corrections to nucleon structure functions which, unlike existing treatments, has the correct kinematic threshold behavior at finite Q{sup 2} in the x -> 1 limit.

Energy Technology Data Exchange (ETDEWEB)

This research activity emphasizes the systems definition and resulting structural requirements for the primary structure of two potential SPS large space structure test articles. These test articles represent potential steps in the SPS research and technology development.

International Nuclear Information System (INIS)

The seawater in the intake structure flows into the large pump to with draw excess heat from the turbine steam condenser. In the intake structure of a nuclear power plant, undesirable pump operating characteristics such as vortices, impeller damages and non-uniform pump-approach flow around the pump bells take place frequently due to poorly-arranged intake geometry. In this study, physical modeling test was performed to predict the hydraulic phenomenon, and proposed flow control devices.

Wastenet

... The relation between turbulence structure and a scalar detected using a new statistical test for the change in fractal dimension of a time-series, Department of Geography, University of Durham Workshop on Coherent Structures in Rivers Keylock C.J., Nishimura K., Nemoto M., Ito Y. 2006. The wake structure from fractal fences: implications for the control of turbulent suspensions, Warwick Turbulence ...

Energy Technology Data Exchange (ETDEWEB)

This document provides structural load requirements and their basis for maintaining the structural integrity of the Hanford Single-Shell Tanks during waste feed delivery and retrieval activities. The requirements are based on a review of previous requirements and their basis documents as well as load histories with particular emphasis on the proposed lead transfer feed tanks for the privatized vitrification plant.

Energy Technology Data Exchange (ETDEWEB)

The Lagrange functions are a family of analytical, complete, and orthonormal basis sets that are suitable for efficient, accurate, real-space, order-N electronic-structure calculations. Convergence is controlled by a single monotonic parameter, the dimension of the basis set, and computational complexity is lower than that of conventional approaches. In this paper we review their construction and applications in linearscaling electronic-structure calculations.

Energy Technology Data Exchange (ETDEWEB)

To assist in attaining the HSE's objective of providing perspective and focus for Safety Case Assessment, a generic model of the structural design process for the foundations of pile supported fixed steel structures has been developed. Interfaces between the foundation design team and other stakeholders have been identified and assessments made of both the magnitude and the potential significance of the uncertainties associated with key elements of the design process. (author)

International Nuclear Information System (INIS)

Comprehensive Structural Integrity is a reference work which covers all activities involved in the assurance of structural integrity. It provides engineers and scientists with an unparalleled depth of knowledge in the disciplines involved. The new online Volume 11 is dedicated to the mechanical characteristics of materials. This paper contains the chapter 11.02 of this volume and is structured as follows: Test techniques; Analysis; Fracture behavior; Fracture toughness tests for nonmetals.

Energy Technology Data Exchange (ETDEWEB)

In ab initio molecular dynamics, whenever information about the potential energy surface is needed for integrating the equations of motion, it is computed 'on the fly' using electronic structure calculations. For Born-Oppenheimer methods, the electronic structure calculations are converged, whereas in the extended Lagrangian approach the electronic structure is propagated along with the nuclei. Some recent advances for both approaches are discussed.

Science.gov (United States)

The Darrieus-type Vertical Axis Wind Turbine (VAWT) presents a variety of unusual structural problems to designers. The level of understanding of these structural problems governs, to a large degree, the success or failure of today's rotor designs. A survey is presented of the technology available for rotor structural design with emphasis on the DOE research program now underway. Itemizations are included of the major structural issues unique to the VAWT along with discussion of available analysis techniques for each problem area. It is concluded that tools are available to at least approximately address the most important problems. However, experimental data for confirmation is rather limited in terms of volume and the range of rotor configurations tested.

Energy Technology Data Exchange (ETDEWEB)

The foundation is a key to safety of any structure built on reclaimed land in coastal areas. This paper gives examples of reclamation methods, ground improvement works, foundations adopted, and consequent land subsidence as for structures directly borne by the underlying ground. Structures built on the recently reclaimed land often stand on piles driven into gravel layers. But an emphasis in pile design in usually placed on bearing capacity, with little consideration given to land subsidence and its effects. Appropriate ground improvement works, if followed by an enough consolidation period, produce satisfactory results for both direct and pile foundations. Low and light structures can be more economically built on direct foundations. It will be still safer for those structures if floating foundations or other measures are taken for preventing increases in load. 5 refs., 16 figs.

British Library Electronic Table of Contents (United Kingdom)

Beaked whales (Ziphiidae) often show highly specialized features, involving bone morphology or structure, in the rostral region of their skulls. Previous studies revealed an extremely derived and peculiar histological structure in the rostrum of the extant Mesoplodon densirostris. In order to assess if this structure is a general feature of ziphiids, the swollen premaxillae of Aporotus recurvirostris, a Miocene species from the North Sea, were studied histologically. These bones are pachyostotic and strongly osteosclerotic. However, their structural organization is entirely different from that of M. densirostris rostrum: they are basically made of a non-remodeled, laminar tissue that was cyclically deposited by the periosteum. As compared to the generalized structure of the premaxillae of ...

Science.gov (United States)

Giant magnetoresistance (GMR) has been used with Eddy current testing to detect small defects not only in thin film structures but also in multilayered metallic structures. This work detected small scratches in the thin film under the surface where these defects were unable to be inspected or monitored by regular testing. In addition, rotational GMR magnetic sensor based Eddy current probes were used for detecting buried corner cracks at the edge of holes in metallic structures. The results of this study proved that giant magnetoresistance is very powerful and effective to sense the magnetic field, which is the result from the perturbation of the Eddy currents caused by a defect. This method can be used for quality control of metallization layers on silicon wafer and to detect cracks in thick structures such as cracks in aging aircraft.

International Nuclear Information System (INIS)

Effect of globular structure parameters - size of primary #alpha#-phase particles (bsub(I)), thickness and amount of plates of secondary #alpha#-phase (bsub(II), #gamma#sub(II#alpha# )) - on a complex of mechanical properties (#sigma#sub(#beta#), S, phi, asub(H), asub(T), Ksub(Q), #sigma#sub(-1), #sigma#_1_0_0"4"5"0, #sigma#sub(0.2/100)) of VT3-1 (#alpha#+#beta#)-titanium alloy is studied. The dependences obtained allow one to determine globular structure parameters, providing necessary mechanical properties. In combination with data on the effect of thermal treatment conditions on structure parameters, results obtained in the paper may be used for structure control to increase a level of required characteristics.

International Nuclear Information System (INIS)

First-principles plane-wave pseudopotential and full-potential linearized-augmented plane-wave methods have been used to study the elastic and electronic properties of several potential superhard RuO_2 phases. The structures, relative stabilities, and the elastic constants and bulk moduli of these phases have been calculated within local-density approximation (LDA) and generalized gradient approximation (GGA). In RuO_2, the LDA and GGA approximations yield smaller and larger lattice constants, respectively, for the Pa3-bar-RuO_2 structure. The internal structural parameter for oxygen atoms in the Pa3-bar structure has a volume dependence that differs from the experimental result and therefore implies a significantly different compression mechanism. The calculated bulk moduli are very similar for the fluorite and Pa3-bar structures and therefore apparently independent of the internal ...

Energy Technology Data Exchange (ETDEWEB)

It has been discovered that the presence of MoO/sub 3/ lowers the ..cap alpha..-..beta.. transition in Sb/sub 2/O/sub 4/ from 935 to 850/sup 0/C with concurrent dissolution of Mo in the high-temperature (..beta..) form. The structure of Mo-doped ..beta..-Sb/sub 2/O/sub 4/ has been investigated by powder neutron diffraction, extended X-ray absorption fine structure (EXAFS) and Raman spectroscopies, and scanning-electron microscopy (SEM). Cell parameters: a = 12.0571 (12) A, b = 4.8335 (1) A, c = 5.3838 (6) A, ..beta.. = 105.579 (5)/sup 0/, monoclinic, space group C2/c, Z = 4. Combining the results of these techniques leads to the hypothesis that Mo is located interstitially within channels of electron density in the Sb/sub 2/O/sub 4/ structure with concurrent vacancy of two Sb/sup III/ atoms. There is no apparent oxygen deficiency in the resulting structure. 25 references, 6 figures, 3 tables.

Energy Technology Data Exchange (ETDEWEB)

We have investigated the structures formed by oligonucleotides composed of two or four repeats of the telomeric sequences from Oxytricha and Tetrahymena. The Oxytricha four-repeat molecule (d(T4G4)4 = Oxy-4) forms structures with increased electrophoretic mobility in nondenaturing gels containing Na+, K+, or Cs+, but not in gels containing Li+ or no added salt. Formation of the folded structure results in protection of a set of dG's from methylation by dimethyl sulfate. Efficient UV-induced cross-links are observed in Oxy-4 and the related sequence from Tetrahymena (d(T2G4)4 = Tet-4), and join thymidine residues in different repeats. Models proposed to account for these data involve G-quartets, hydrogen-bonded structures formed from four guanosine residues in a square-planar array. We propose that the G-quartet structure must be dealt with in vivo by the telomere ...

Energy Technology Data Exchange (ETDEWEB)

There are two kinds of uncertainties in safety assessment of engineering structures. One is of the nature of randomness, and the other fuzziness. Fuzzy uncertainties exist in defining certain structural performances, conditions, parameters, and their interrelationships. The theory of fuzzy sets should be employed to cope with the fuzzy uncertainties. In this paper, a general definition for structural failure considering the fuzzy uncertainties is introduced firstly. Failure of the structure is modelled by a fuzzy event, and described by the membership function. The limit state surface is then replaced by a fuzzy limit state zone, in which every point represents a state belonging to the failure with a certain degree of membership. Then a fuzzy optimization problem for solving the reliability index is formulated. In classical structural reliability theory, the reliability index is ...

Science.gov (United States)

In the course of previous composite structures test programs, the need for and the feasibility of developing analyses for scale-up effects has been demonstrated. The analysis techniques for scale-up effects fall into two categories. The first category pertains to developing analysis methods independently for a single, unique failure mode in composites, and using this compendium of analysis methods together with a global structural model to identify and predict the response and failure mode of full-scale built-up structures. The second category of scale-up effects pertains to similitude in structural validation testing. In this latter category, dimensional analysis is used to develop scale-up laws that enable extrapolation of sub-scale component test data to full-scale structures. This viewgraph presentation describes the approach taken and some developments accomplished in the first ...