Energy Technology Data Exchange (ETDEWEB)

The concordance of standard big bang nucleosynthesis theory and the related observations of the light element isotopes (including some new higher {sup 4}He abundances) will be reviewed. Implications of BBN on chemical evolution, dark matter and constraints on particle properties will be discussed.

CERN Document Server

We have derived elemental abundances for a sample of nine IRAS sources with colours similar to those of post-AGB stars. For IRAS 01259+6823, IRAS 05208-2035, IRAS 04535+3747 and IRAS 08187-1905 this is the first detailed abundance analysis based upon high resolution spectra. Mild indication of s-processing for IRAS 01259+6823, IRAS 05208-2035 and IRAS 08187-1905 have been found and a more comprehensive study of s-process enhanced objects IRAS 17279-1119 and IRAS 22223+4327 have been carried out. We have also made a contemporary abundance analysis of the high galactic latitude supergiants BD+39 4926 and HD 107369. The former is heavily depleted in refractories and estimated [Zn/H] of -0.7 dex most likely gives initial metallicity of the star. For HD 107369 the abundances of alpha and Fe-peak elements are similar to those of halo objects and moderate deficiency of s-process elements is seen. IRAS ...

International Nuclear Information System (INIS)

Depletion studies are used to infer the presence of mantles and to constrain grain evolutionary models in the diffuse interstellar medium. The presence of these mantles appears to be important in the evolution of the grains inside diffuse as well as dense clouds. In dense clouds where the element-to-element abundances sometimes differ from those found in diffuse clouds, empirical relationships are starting to emerge between gas abundances and various types of peculiar selective extinction. These peculiar extinction curves may be the results of nonvolatile mantle formation on grain cores or may reflect chemical differences due to variations in the intrinsic metalicity from one cloud to another. A simple model of the time evolution of a parcel of gas and dust as observed by the depletion of two elements is presented. Different studies of grain evolution and selective extinction are discussed and compared.

Energy Technology Data Exchange (ETDEWEB)

In this thesis we study the relic density n{sub {chi}} of non--relativistic long--lived or stable particles {chi} in various non--standard cosmological scenarios. First, we discuss the relic density in the non--standard cosmological scenario in which the temperature is too low for the particles {chi} to achieve full chemical equilibrium. We also investigated the case where {chi} particles are non--thermally produced from the decay of heavier particles in addition to the usual thermal production. In low temperature scenario, we calculate the relic abundance starting from arbitrary initial temperatures T{sub 0} of the radiation--dominated epoch and derive approximate solutions for the temperature dependence of the relic density which can accurately reproduces numerical results when full thermal equilibrium is not achieved. If full equilibrium is reached, our ansatz no longer reproduces the correct temperature dependence of the {chi} number ...

Energy Technology Data Exchange (ETDEWEB)

A considerable amount of chemical knowledge of marine sediments has been acquired in recent years but has not yet been utilized by paleomagnetists. On the other hand, geochemists are often unaware of the usefulness of numerous magnetic techniques. In this review we try to bridge this gap, and in particular, we outline many of the chemical and magnetic principles that should allow paleomagnetists to better identify and undertand chemical changes that affect the magnetic properties of marine sediments. The chemical principles include those for distinguishing the four major sources of sediments (continental, biological, authigenic/hydrogenous, volcanic/hydrothermal) from one another by determining elemental abundance distributions, as well as for investigating the stabilities of mineral phases relative to changes in pE and pH. The magnetic principles include the effects of authigenesis ...

CERN Document Server

We investigate the chemical and observational implications of repetitive transient dense core formation in molecular clouds. We allow a transient density fluctuation to form and disperse over a period of 1 Myr, tracing its chemical evolution. We then allow the same gas immediately to undergo further such formation and dispersion cycles. The chemistry of the dense gas in subsequent cycles is similar to that of the first, and a limit cycle is reached quickly (2 - 3 cycles). Enhancement of hydrocarbon abundances during a specific period of evolution is the strongest indicator of previous dynamical history. The molecular content of the diffuse background gas in the molecular cloud is expected to be strongly enhanced by the core formation and dispersion process. Such enhancement may remain for as long as 0.5 Myr. The frequency of repetitive core formation should strongly determine the level of background molecular enhancement. ...

CERN Document Server

One of the most interesting discoveries of the X-ray Telescope and EUV Imaging Spectrometer (EIS) on board the Hinode solar observatory is the presence of persistent high temperature high speed outflows from the edges of active regions. Measurements by EIS indicate that the outflows reach velocities of 50 km/s with spectral line asymmetries approaching 200 km/s. It has been suggested that these outflows may lie on open field lines that connect to the heliosphere, and that they could potentially be a significant source of the slow speed solar wind. A direct link has been difficult to establish, however. In this letter, we use EIS measurements of spectral line intensities that are sensitive to changes in the relative abundance of Si and S as a result of the first ionization potential (FIP) effect, to measure the chemical composition in the outflow regions of AR 10978 over a period of 5 days in December 2007. We find that Si is always enhanced ...

CERN Document Server

Several complex organic molecules are routinely detected in high abundances towards hot cores and hot corinos. For many of them, their paths of formation in space are uncertain, as gas phase reactions alone seem to be insufficient. In this paper, we investigate a possible solid-phase route of formation for methyl formate (HCOOCH3). We use a chemical model updated with recent results from an experiment where simulated grain surfaces were irradiated with 200 keV protons at 16 K, to simulate the effects of cosmic ray irradiation on grain surfaces. We find that this model may be sufficient to reproduce the observed methyl formate in dark clouds, but not that found in hot cores and corinos.

Energy Technology Data Exchange (ETDEWEB)

The relative abundances of iron-peak elements produced by the e-process in a supernova outburst are calculated. The results agree quite well with the cosmic abundances of elements in the range Z=23--28.

International Nuclear Information System (INIS)

We have observed the CH_3OH J = 2-1, SiO J = 2-1, C"3"4S J = 2-1, H"1"3CO"+ J = 1-0, HN"1"3C J = 1-0, CCH N = 1-0, OCS J = 8-7, and SO J_N = 2_2-1_1 lines toward 20 massive clumps, including Midcourse Space Experiment (MSX) 8 #mu#m dark sources (infrared dark clouds) and MSX 8 #mu#m sources, by using the Nobeyama Radio Observatory 45 m telescope. We have found that the velocity widths of the CH_3OH and C"3"4S lines are broader than those of the H"1"3CO"+ line in the MSX dark sources. On the other hand, they are comparable to the velocity width of the H"1"3CO"+ line in the MSX sources. In addition, the [SiO]/[H"1"3CO"+] abundance ratio is found to be enhanced in the MSX dark sources in comparison with the MSX sources. These results suggest that shocks caused by interaction between an outflow and an ambient dense gas would have substantial impact on the chemical composition of the MSX dark sources. The velocity widths of the CH_3OH and C"3"4S ...

International Nuclear Information System (INIS)

We report biological changes at several UK Acid Waters Monitoring Network lakes and streams that are spatially consistent with the recovery of water chemistry induced by reductions in acid deposition. These include trends toward more acid-sensitive epilithic diatom and macroinvertebrate assemblages, an increasing proportional abundance of macroinvertebrate predators, an increasing occurrence of acid-sensitive aquatic macrophyte species, and the recent appearance of juvenile (<1 year old) brown trout in some of the more acidic flowing waters. Changes are often shown to be directly linked to annual variations in acidity. Although indicative of biological improvement in response to improving water chemistry, 'recovery' in most cases is modest and very gradual. While specific ecological recovery endpoints are uncertain, it is likely that physical and biotic interactions are influencing the rate of recovery of certain groups of organisms at particular sites. - ...

International Nuclear Information System (INIS)

We present an abundance analysis based on high-resolution spectra of 10 stars selected to span the full range in metallicity in the Ursa Minor (UMi) dwarf spheroidal (dSph) galaxy. We find that [Fe/H] for the sample stars ranges from -1.35 to -3.10 dex. Combining our sample with previously published work for a total of 16 luminous UMi giants, we establish the trends of abundance ratios [X/Fe] as functions of [Fe/H] for 15 elements. In key cases, particularly for the #alpha#-elements, these trends resemble those for stars in the outer part of the Galactic halo, especially at the lowest metallicities probed. The neutron-capture elements show an r-process distribution over the full range of Fe metallicity reached in this dSph galaxy. This suggests that the duration of star formation in the UMi dSph was shorter than in other dSph galaxies. The derived ages for a larger sample of UMi stars with more uncertain metallicities also suggest a population ...

International Nuclear Information System (INIS)

The chemical composition and evolution of formation waters associated with gas production in the Palm Valley field, Northern Territory, has important implications for reservoir management, saline water disposal, and gas reserve calculations. Historically, the occurrence of saline formation water in gas fields has been the subject of considerable debate. A better understanding of the origin, chemical evolution and movement of the formation water at Palm Valley has important implications for future reservoir management, disposal of highly saline water and accurate gas reserves estimation. Major and trace element abundance data suggest that a significant component of the highly saline water from Palm Valley has characteristics that may have been derived from a modified evaporated seawater source such as an evaporite horizon. The most dilute waters probably represent condensate and the variation in the chemistry of the ...

Energy Technology Data Exchange (ETDEWEB)

The Earth`s troposphere and hydrosphere contain abundant naturally generated dust. The ultimate source materials from which the terrestrially produced dust is generated are the various rock types exposed at the Earth`s surface. Natural dust is a composite of (1) lithic, primary mineral grains; (2) mineral grains formed by secondary chemical reactions; (3) volcanic ash and dust; (4) salts from sea sprays; (5) extra-terrestrial dust; and (6) biologic materials. In this paper the various pathways to the natural generation of dust (via the hydrologic cycle) will be discussed, and two geologically well-known natural dust sources will be described, paying particular attention to quantitative measurements of the dusts from these areas. General dust studies that provide data on possibly global background levels will be presented as well.. A few general aspects of the mineralogical characterization of dust particles and a discussion of some of the ...

UK PubMed Central (United Kingdom)

The abundance of host-seeking Ixodes scapularis nymphs, the principal vector for the Lyme disease agent, Borrelia burgdorferi, in Old Lyme, Lyme, and East Haddam, Connecticut,...Full Text Available

International Nuclear Information System (INIS)

... Oceanographic Institution, Mass. (USA) v. 8 p. 439-442. abundance

Energy Technology Data Exchange (ETDEWEB)

The problem on change of deuterium abundance in the process of galactic evolution (star evolution, supernova explosions, nucleosynthesis in supermassive objects) is considered. It is shown that the observable deuterium quantity in the interstellar medium must correspond to its cosmological abundance. This conclusion is independent of the rate of accretion of intergalactic gas by Galaxy. The effect of hypothetical pregalactic active objects on cosmological deuterium is small. It is poind out that observations of interstellar deuterium in absorbtion at lambda=91.6 cm are significant.

British Library Electronic Table of Contents (United Kingdom)

We used a 13-year time series of abundance estimates of breeding Northern Saw-whet Owls (Aegolius acadicus), and of small mammals from central Ontario, Canada, to assess the numerical response of the owls to small-mammal prey species. We found that the finite rate of increase of breeding owls was directly related to estimates of red-backed vole (Myodes gapperi) abundance. Thus, it appeared that the owls were nomadic, and made decisions about where to breed based on vole supply. The owls showed a much weaker response to deer mouse (Peromyscus maniculatus) abundance. Across all years, 55% of variation in owl rate of increase could be uniquely attributed to vole abundance, whereas only 3% could be attributed to mouse abundance. Consistent with the model of nomadism, there was only a weak rela...

Science.gov (United States)

New sets of cross sections for the production of krypton isotopes from targets of Rb, Sr, Y, and Zr were constructed primarily on the bases of experimental excitation functions for Kr production from Y. These cross sections were used to calculate galactic-cosmic-ray and solar-proton production rates for Kr isotopes in the moon. Spallation Kr data obtained from ilmenite separates of rocks 10017 and 10047 are reported. Production rates and isotopic ratios for cosmogenic Kr observed in ten well-documented lunar samples and in ilmenite separates and bulk samples from several lunar rocks with long but unknown irradiation histories were compared with predicted rates and ratios. The agreements were generally quite good. Erosion of rock surfaces affected rates or ratios for only near-surface samples, where solar-proton production is important. There were considerable spreads in predicted-to-observed production rates of /sup 83/Kr, due at least in part to uncertainties in ...

International Nuclear Information System (INIS)

The chemical composition and evolution of produced waters associated with gas production in the Palm Valley gas field, Northern Territory, has important implications for issues such as gas reserve calculations, reservoir management and saline water disposal. The occurrence of saline formation water in the Palm Valley field has been the subject of considerable debate. There were no occurrences of mobile water early in the development of the field and only after gas production had reduced the reservoir pressure, was saline formation water produced. Initially this was in small quantities but has increased dramatically with time, particularly after the initiation of compression in November 1996. The produced waters range from highly saline (up to 300,000 mg/L TDS), with unusual enrichments in Ca, Ba and Sr, to low salinity fluids that may represent condensate waters. The Sr isotopic compositions of the waters ("8"7Sr/"8"6Sr = 0.7041-0.7172) are also variable but do not ...

International Nuclear Information System (INIS)

New stellar models which track the production and destruction of "3He (and D) have been evolved for a range of stellar masses (0.65#<=#M/M_c_i_r_c_l_e_-_d_o_t#<=#100), metallicities (0.01#<=#Z/Z_c_i_r_c_l_e_-_d_o_t#<=#1), and initial (main-sequence) "3He mass fractions (10"-"5#<=#X_3_,_M_S#<=#10"-"3). Armed with the "3He yields from these stellar models we have followed the evolution of D and "3He using a variety of chemical evolution models with and without infall of primordial or processed material. Production of new "3He by the lower mass stars overwhelms any reasonable primordial contributions and leads to predicted abundances in the presolar nebula and/or the present interstellar medium in excess of the observationally inferred values. This result, which obtains even for zero primordial D and "3He, and was anticipated by Rood, Steigman, ampersand Tinsley is insensitive to the choice of chemical ...

Energy Technology Data Exchange (ETDEWEB)

The isotopic enrichment of copper ions in a positive column Cu-Nu discharge using optogalvanic excitation is analyzed with a rate equation model With excitation at 510.6 nm, the fraction of the ions belonging to the 63-amu isotope of copper is enriched relative to the neutral abundance. Enrichment as large as 10% is calculated when the initial abundance of the neutral isotope is small (< or =0.1) and the discharge current density is large (> or =75 mA/cm/sup 2/). The degree of enrichment is examined as a function of the initial abundance, discharge current, the rate of charge exchange, and the diameter of the discharge tube.

UK PubMed Central (United Kingdom)

Cultures of chick skin fibroblasts were dissolved in solutions of sodium dodecyl sulphate, and their entire protein content was examined by gel electrophoresis. The most abundant species migrated in...Full Text Available

Science.gov (United States)

... Anastrepha fraterculus (Wiedemann) and Ceratitis capitata (Wiedemann), including Acca sellowiana (O. Berg) Burret, Campomanesia xanthocarpa O. Berg, Psidium ... ...

Science.gov (United States)

... abundance though an effect on escapement. The lobster aquaculture model continues to be updated as new biological ... become available. A monograph on the economics of aquaculture is near completion....

Energy Technology Data Exchange (ETDEWEB)

This study reports on the physical-chemical behaviour of swelling di-octahedral clays (smectites) and their interaction with aqueous solutions and bacteria (Shewanella putrefaciens). Experimental results are presented for compacted clays, hydrated under confined volume conditions, using a new type of reaction-cell (the 'wet-cell' of Warr and Hoffman, 2004) that was designed for in situ X-ray diffraction (XRD) measurement. For comparison, dispersed clay systems were studied using standard batch solutions subjected to varying degrees of agitation. The combination of time-dependent in situ XRD measurements with gravimetric measurements and calculated diffraction patterns using the CALCMIX software (Plancon and Drits, 1999) allowed to successful quantification of the dynamics of water uptake and storage. This analytical procedure combined with published water vapour adsorption data enabled determination of the abundance of ...

Energy Technology Data Exchange (ETDEWEB)

Basalt and diabase from the Cretaceous Dumisseau Formation, southern Haiti have Mg-numbers of 43-63, TiO/sub 2/ contents of 1.6-3.9% and La abundances of 3.6-15.3 ppm. LaTa ratios average 10, and indicate that the basalts are oceanic in character, distinct from the arc associations forming the northern part of Haiti. Oldest lavas have low TiO/sub 2/, (1.6%) and are LREE-depleted, similar to N-MORBs, whereas overlying lavas have higher TiO/sub 2/ (2-3.9%) and are LREE-enriched, similar to E-MORBs or hotspot basalts. /sup 87/Sr/sup 86/Sr ratios vary from 0.70280 to 0.70316, /sup 143/Nd/sup 144/Nd from 0.512929 to 0.513121, and /sup 206/Pb/sup 204/Pb from 19.00 to 19.27 LREE-depleted lavas have high /sup 143/Nd/sup 144/Nd (0.51309-0.51310) typical of MORBs, whereas /sup 143/Nd/sup 144/Nd in the LREE-enriched lavas varies widely (0.512929-0.513121). Chemical features of the Dumisseau basalts are equivalent to those of Caribbean seafloor basalts ...

International Nuclear Information System (INIS)

An IAEA databank lists a number of reported cases of illicitly trafficked nuclear or other radioactive materials. Apart from the traditional concern with nuclear proliferation, the post September 11th public is now wary of a possible attack by terrorists with a nuclear or radiation dispersion device (RDD). Until now, the seized quantities have not been sufficient to manufacture a nuclear explosive device, but they might be enough to construct an RDD. Recognizing the latent global challenge to public health and safety, the G8 States (Japan, USA, Germany, France, UK, Italy, Canada, and Russia) have called for 'joint international efforts to identify and suppress illicit supply' of, and demand for, nuclear material and to deter potential traffickers. One measure gaining in significance is to identify seized material and trace it back to its origin the objective of an emerging science known as nuclear forensics. Repeatedly nuclear or other radioactive material of unknown origin are ...

Energy Technology Data Exchange (ETDEWEB)

The Bioenergy Feedstock Development Program, Environmental Sciences Division, Oak Ridge National Laboratory is developing poplars (Populus species and hybrids) as sources of renewable energy, i.e., ethanol. Notable increases in adaptability, volume productivity, and pest/stress resistance have been achieved via classical selection and breeding and intensified cultural practices. Significant advances have also been made in the efficiencies of harvesting and handling systems. Given these and anticipated accomplishments, program leaders are considering shifting some attention to genetically modifying feedstock physical and chemical properties, so as to improve the efficiency with which feedstocks can be converted to ethanol. This report provides an in-depth review and synthesis of opportunities for and feasibilities of genetically modifying feedstock qualities via classical selection and breeding, marker-aided selection and breeding, and genetic transformation. ...

International Nuclear Information System (INIS)

The determination of Li and proton-capture element abundances in globular cluster (GC) giants allows us to constrain several key questions on the multiple population scenarios in GCs, from formation and early evolution to pollution and dilution mechanisms. In this Letter, we present our results on Li abundances for a large sample of giants in the intermediate-metallicity GC NGC 6121 (M4), for which Na and O have been already determined by Marino et al. The stars analyzed are both below and above the red giant branch bump luminosity. We found that the first and second generation stars share the same Li content, suggesting that a Li production must have occurred. This provides strong observational evidence supporting the scenario in which asymptotic giant branch stars are GC polluters.

CERN Document Server

We present constraints on theoretical models of Type Ia SNe using spatially resolved ASCA X-ray spectroscopy of four galaxy clusters: Abell 496, Abell 2199, Abell 3571 & Perseus. All four clusters have central Fe abundance enhancements and an ensemble of abundance ratios are used to show that most of the Fe in the central regions of the clusters comes from SN Ia. At the center of each cluster, simultaneous analysis of spectra from all ASCA instruments shows that the Ni to Fe abundance ratio (normalized by the solar ratio) is ~ 4. We use the Ni/Fe ratio as a discriminator between SN Ia explosion models: the Ni/Fe ratio of ejecta from the "Convective Deflagration" model W7 is consistent with the observations, while those of "delayed detonation" models are not consistent at the 90% confidence level.

UK PubMed Central (United Kingdom)

Tocopherols (vitamin E) are lipophilic antioxidants synthesized by all plants and are particularly abundant in seeds. Despite cloning of the complete suite of tocopherol biosynthetic enzymes and successful...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundCalcitonin gene related peptide (CGRP) is a neuropeptide that is abundant in the sensory neurons which innervate bone. The effects of CGRP on isolated bone cells have been...Full Text Available

UK PubMed Central (United Kingdom)

A new strain of mouse hepatitis virus (MHV) was isolated from pooled gut suspensions from an epizootic of lethal enteritis in newborn mice. Negative-contrast electron microscopy showed an abundance...Full Text Available

UK PubMed Central (United Kingdom)

SUMMARYTwo abundant classes of mobile elements, namely Alu and L1 elements, continue to generate new retrotransposon insertions in human genomes. Estimates suggest that these...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundMalignant catarrhal fever (MCF) is a lethal disease of cattle, characterized by vasculitis, necrosis, and accumulation of activated, dysregulated cytotoxic lymphocytes...Full Text Available

Science.gov (United States)

... protein is abundant in cytosolic portions of malignant epithelial tissue (Fig. 3A). In contrast, the degree of CCTβ staining in normal epithelial tissue (Fig. 3B) or connective tissues was much weaker ......

Medline Plus

... also include a healthy diet that included abundant antioxidants, such as vitamin C, vitamin E, and lycopene. ... exfoliants, the higher-level moisturizers as well as antioxidants as my night product. A very rich moisturizer ...

British Library Electronic Table of Contents (United Kingdom)

The juvenile fish community associated with natural, degraded and replanted Sonneratia alba mangroves in Gazi Bay was sampled during the South East and North East monsoons between April 2002 and June 2003. A total of 1800 individuals belonging to 49 taxa and 34 families were collected from the intertidal forest using stake nets. Fish abundance ranged from 0.93+-0.20ind. m-2 (SEM02) to 1.16+-0.18ind. m-2 (SEM03) between seasons and between 0.54+-0.07ind. m-2 and 1.64+-0.33ind. m-2 for individual sites across seasons. Five taxa accounted for approximately 70% of the total fish abundance, with Gobidae and Gerres oyena dominating. ANOSIM revealed seasonal differences in fish species composition and abundance (p=0.01) due to fluctuating abundances of primarily Terapon sp. and Thryssa sp. The ma...

UK PubMed Central (United Kingdom)

In this study we have profiled the free sterol content of cerebrospinal fluid by a combination of charge tagging and liquid chromatography-tandem mass spectrometry. Surprisingly, the most abundant cholesterol...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A highly dispersed limonite catalyst was shown to have advantageous properties in a commercial liquefaction plant: it has high catalytic activity, low cost for catalyst production and abundant resources. 3 refs., 3 figs., 2 tabs.

International Nuclear Information System (INIS)

We present a detailed investigation of SBS 1150+599A, a close binary star hosted by the planetary nebula PN G135.9+55.9 (TS 01). The nebula, located in the Galactic halo, is the most oxygen-poor known to date and is the only one known to harbor a double degenerate core. We present XMM-Newton observations of this object, which allowed the detection of the previously invisible component of the binary core, whose existence was inferred so far only from radial velocity (RV) and photometric variations. The parameters of the binary system were deduced from a wealth of information via three independent routes using the spectral energy distribution (from the infrared to X-rays), the light and RV curves, and a detailed model atmosphere fitting of the stellar absorption features of the optical/UV component. We find that the cool component must have a mass of 0.54 #+-# 0.2 M_s_u_n, an average effective temperature, T_e_f_f, of 58,000 #+-# 3000 K, a mean radius of 0.43 #+-# 0.3 R_s_u_n, a gravity, ...

International Science & Technology Center (ISTC)

Development of Methods and Apparatus for Processes Diagnostics in Plasma Reactors at the Neutralization of Chemical Herbiside and Pestiside

International Science & Technology Center (ISTC)

Computer-Aided Prediction of Chemical Ecotoxicity on the basis of Quantitative Structure-Activity Relationships with the Use of Physico-Chemical Descriptors, Including H-bond Parameters

UK PubMed Central (United Kingdom)

Chemical leucoderma is an industrial disorder in developed countries and the common causative chemicals are phenols and catechols. Due to stringent controls and preventive measures the incidence has...Full Text Available

Science.gov (United States)

PMID:12722515

Energy Technology Data Exchange (ETDEWEB)

Short communication

Energy Technology Data Exchange (ETDEWEB)

Short communication. 3 refs.

Science.gov (United States)

No abstract prepared.

Science.gov (United States)

No abstract available.

CERN Document Server

We study spectroscopically determined iron abundances of 642 solar-type stars to search for the signature of accreted iron-rich material. We find that the metallicity [Fe/H] of a subset of 466 main sequence stars, when plotted as a function of stellar mass, mimics the pattern seen in lithium abundances in open clusters. Using Monte Carlo models we find that, on average, these stars have accreted about 0.4 Earth masses of iron while on the main sequence. A much smaller sample of 19 stars in the Hertzsprung gap, which are slightly evolved and whose convection zones are significantly more massive, have lower average [Fe/H], and their metallicity shows no clear variation with stellar mass. These findings suggest that terrestrial-type material is common around solar type stars.

British Library Electronic Table of Contents (United Kingdom)

Seasonal and habitat calliphorid abundance and distribution were examined weekly for two years (2001-2003) in Santa Clara County, California, using sentinel traps baited with bovine liver. Of the 34,389 flies examined in three defined habitats (rural, urban, and riparian), 38% of the total catch represented Compsomyiops callipes (Bigot) and 23% represented Phormia regina (Meigen). Other flies collected in this survey included Calliphora vomitoria (Linnaeus), Calliphora latifrons (Hough), Lucilia sericata (Meigen), Lucilia cuprina (Wiedemann), and Lucilia mexicana (Macquart), which is a new record for the area. Multivariate MANOVA and ANOVA (P 0.05) analysis indicate significant seasonal habitat preference for all fly species examined. This information may be used to identify potentially fo...

Energy Technology Data Exchange (ETDEWEB)

Observations are reported of the lithium feature (6708 A) in some bright southern stars, most of which are F, G, or K dwarfs. Three of these stars have been suggested as belonging to the Ursa Major Group. Two of these three have the large Li abundance and strong Ca II H and K emission expected of such young stars. The third potential Ursa Major Group member has little Li, but is also not a true kinematic member. No stars were found with abnormal (Li-6)/(Li-7) ratios, in accord with other recent analyses. Thus it appears that all stars have (Li-6)/(Li-7) near the solar/terrestrial value of 0.08. 31 references.

Energy Technology Data Exchange (ETDEWEB)

It has been shown that not only there are abundant oil, gas, coal, coal-bed gas, groundwater and giant uranium deposits but also there are abundant oil shale resources in Ordos basin. It has been shown also that the thickness of oil shale is, usually, 4-36m, oil-bearing 1.5%-13.7%, caloric value 1.66-20.98MJ/kg. The resource amount of oil shale with burial depth less than 2000 m is over 2000x108t (334). Within it, confirmed reserve is about 1x108t (121). Not only huge economic benefit but also precious experience in developing oil shale may be obtained in Ordos basin.

British Library Electronic Table of Contents (United Kingdom)

Thinning and burning forests established on revegetated mine pits in jarrah (Eucalyptus marginata) forests of south-west Australia is being considered as a management option to accelerate succession in sites with excessive tree densities. To assess the impact of thinning and burning on reptiles and small mammals, we installed trapping grids in eight thinned and burned sites, each paired with untreated controls. Of the eight pairs, four were in rehabilitated sites (planted with nonlocal species) and four were in restored sites (seeded with local species). Thinning and burning had no significant impact on the small mammal community, although Cercatetus concinnus was more abundant in rehabilitated sites. In contrast, thinning and burning significantly increased reptile abundance and species r...

British Library Electronic Table of Contents (United Kingdom)

The integral membrane protein synaptophysin is one of the most abundant polypeptide components of synaptic vesicles. It is not essential for neurotransmission despite its abundance but is believed to modulate the efficiency of the synaptic vesicle cycle. Detailed behavioral analyses were therefore performed on synaptophysin knockout mice to test whether synaptophysin affects higher brain functions. We find that these animals are more exploratory than their wild type counterparts examining novel objects more closely and intensely in an enriched open field arena. We also detect impairments in learning and memory, most notably reduced object novelty recognition and reduced spatial learning. These deficits are unlikely caused by impaired vision, since all electroretinographic parameters measur...

British Library Electronic Table of Contents (United Kingdom)

Coral populations have precipitously declined on Caribbean reefs while algal abundance has increased, leading to enhanced competitive damage to corals, which likely is mediated by the potent allelochemicals produced by both macroalgae and benthic cyanobacteria. Allelochemicals may affect the composition and abundance of coral-associated microorganisms that control host responses and adaptations to environmental change, including susceptibility to bacterial diseases. Here, we demonstrate that extracts of six Caribbean macroalgae and two benthic cyanobacteria have both inhibitory and stimulatory effects on bacterial taxa cultured from the surfaces of Caribbean corals, macroalgae, and corals exposed to macroalgal extracts. The growth of 54 bacterial isolates was monitored in the presence of l...

Energy Technology Data Exchange (ETDEWEB)

Chemical oxidation is a treatment technology that uses powertul chemical oxidizers to destroy organic contaminants. Typical oxidizers used in chemical oxidation processes include ozone, hydrogen peroxide, chlorine, and potassium permanganate. The chemical reaction products are usually simple organic compounds, such as carboxylic acids, and/or inorganic compounds, such as carbon dioxide, water, and simple inorganic complexes (e.g., chloride salts, in the case of chemical oxidation treatment of chlorinated solvents).

Energy Technology Data Exchange (ETDEWEB)

A robust fusion of the agricultural, industrial biotechnology, and energy industries can create a new strategic national capability for energy independence and climate protection. In his State of the Union Address (Bush 2006), President George W. Bush outlined the Advanced Energy Initiative, which seeks to reduce our national dependence on imported oil by accelerating the development of domestic, renewable alternatives to gasoline and diesel fuels. The president has set a national goal of developing cleaner, cheaper, and more reliable alternative energy sources to substantially replace oil imports in the coming years. Fuels derived from cellulosic biomass - the fibrous, woody, and generally inedible portions of plant matter - offer one such alternative to conventional energy sources that can dramatically impact national economic growth, national energy security, and environmental goals. Cellulosic biomass is an attractive energy feedstock because it is an abundant, ...

UK PubMed Central (United Kingdom)

Programmed cell death (PCD) is triggered when Pto, a Ser-Thr protein kinase, recognizes either the AvrPto or AvrPtoB effector from Pseudomonas syringae pv tomato. This...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

It is becoming clear that simple sequence repeats (SSRs) play a significant role in fungal genome organization, and they are a large source of genetic markers for population genetics and meiotic maps. We identified SSRs in the Laccaria bicolor genome by in silico survey and analyzed their distribution in the different genomic regions. We also compared the abundance and distribution of SSRs in L. bicolor with those of the following fungal genomes: Phanerochaete chrysosporium, Coprinopsis cinerea, Ustilago maydis, Cryptococcus neoformans, Aspergillus nidulans, Magnaporthe grisea, Neurospora crassa and Saccharomyces cerevisiae. Using the MISA computer program, we detected 277,062 SSRs in the L. bicolor genome representing 8% of the assembled genomic sequence. Among the analyzed basidiomycetes, L. bicolor exhibited the highest SSR density although no correlation between relative abundance and the genome sizes was observed. In most genomes the short ...

Energy Technology Data Exchange (ETDEWEB)

The results of the six meetings in the years 1976 through 1981 of the Panel on Reference Nuclear Data is reviewed, as well as the results of other studies and workshops. A brief review of how current programs are meeting the expressed nuclear data needs of professional groups is also presented. The types of data included in the review are reaction cross sections, isotopic abundances, atomic masses, nuclear structure, radioactive decay, and fission.

UK PubMed Central (United Kingdom)

Phthalate esters (PE's) are plasticizers used to soften PVC-based medical devices. PE's are the most abundant man-made pollutants and increase the risk of developing an allergic respiratory disease...Full Text Available

Environmental Research Database

DescriptionPhytoplankton is the collective name given to the microscopic floating plants in seas and lakes. Under certain conditions, the abundance of phytoplankton as a whole or of one or more species in particular, can reach a magnitude at which it is visible through discolouration of the sea. Some of these blooms because of the colour of the water have been called 'Red Tides'. Blooms of some 300 species of the phytoplankton are known as Harmful Algal Bloom (HAB) species in recognition of their poten [continued...

UK PubMed Central (United Kingdom)

The abundant microbial population in a 3,043-m-deep Greenland glacier ice core was dominated by ultrasmall cells (<0.1 μm³) that may represent intrinsically small organisms...Full Text Available

UK PubMed Central (United Kingdom)

Urine is a potential source of diagnostic biomarkers for detection of diseases, and is a very attractive means of non-invasive biospecimen collection. Nonetheless, proteomic measurement in urine...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Ammonia is a common and highly toxic pollutant which, in sufficient quantities, will adversely affect aquatic organisms. This ammonia criteria document for salt water will allow establishment of regulatory standards for ammonia discharge into estuaries, near coastal zones and oceans. Possible adverse impacts in highly sensitive and abundant ecosystems such as estuaries make regulation particularly important.

Energy Technology Data Exchange (ETDEWEB)

The presence of the nitrogen-fixing shrub, Alnus incana ssp. rugosa, influences the concentration of inorganic nitrogen in surface waters in the Adirondack Mountain region of northern New York. - The purpose of this research was to determine the abundance of the nitrogen-fixing shrub, Alnus incana ssp. rugosa (speckled alder), in shrub wetlands of the Adirondack Mountain region of New York State and to determine whether its abundance affects the concentration or accumulation of inorganic nitrogen in wetland substrates. Alder/willow wetlands are the second most common wetland type in the Adirondack region. The Adirondack Park Agency's digital GIS database of wetland types was used to determine the areal extent of alder/willow wetlands in the Adirondacks. Randomly selected wetlands were sampled to determine the size and abundance of alder. Alder densities averaged {approx}7000 stems ha{sup -1} and alder was present ...

UK PubMed Central (United Kingdom)

BackgroundA key question in the risk assessment of exposures to multiple chemicals is whether mixture effects may occur when chemicals are combined at low doses which individually...Full Text Available

UK PubMed Central (United Kingdom)

Environmental chemicals that function as estrogens have been suggested to be associated with an increase in disease and dysfunctions in animals and humans. To characterize chemicals that may act as...Full Text Available

UK PubMed Central (United Kingdom)

The experimental data set used to evaluate site-specific histopathologic correspondence between the morphologic end points of toxicity and carcinogenicity comprises 130 chemical carcinogenesis studies....Full Text Available

International Science & Technology Center (ISTC)

Hard Nano-Strutural Coatings Resistant to the Extreme Conditions of Chemical, Abrasive and High Energy Media for Thermonuclear Power, Oil and Gas and Chemical Industries

Science.gov (United States)

... 6 lit. CHEMICAL CARCINOGENESIS TESTING AND RELATED ISSUES- ILn SUBCHRONIC STUDIES AND RELATED ISSUES 0 o Andrew Sivak 0 ...

UK PubMed Central (United Kingdom)

The immune system plays a crucial role in maintaining health; however, accumulating evidence indicates that this system can be the target for immunotoxic effects caused by a variety of chemicals including...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The thermochemical calculations performed with a large number of elements to describe the chemical system in a Phebus FP test allow the following conclusions: The metallic absorber materials play a significant role in fission product speciation. At around 1000 C and above, silver iodide is the dominant iodine carrier in a full steam atmosphere in both FPT0 and FPT1. At lower temperatures, cadmium iodide takes over. In a reduced environment, indium iodide becomes important. Caesium iodide does certainly appear; at certain test conditions it becomes the major iodine transporting vehicle. But its role is not greater than that of the other iodides. It has more chances in FPT1 than in FPT0. Chlorine, which was present in FPT0 as a contaminant in relatively large amounts, does not prevent the iodine from forming Csl. Both share the caesium like partners. The evolution of caesium chloride and iodide proceeds in parallel. When CsCl is abundant, Csl is ...

International Nuclear Information System (INIS)

Positive identification of Martian pseudocraters would be a strong indication of past occurrence of ice at or near the surface of Mars. The basis for suggesting that small cones on Mars are pseudocraters includes: (1) small size, (2) abundant but patchy distribution on what appear to be volcanic plains, (3) presence of other features suggestive of surface or subsurface ice, (4) morphological similarities to Icelandic pseudocraters, and (5) the similarity in distribution of crater/cone diameter ratios to Icelandic pseudocraters. This last morphometric parameter may be the most important, since other possible small terrestrial volcanic analogs have very different crater/cone diameter ratio distributions. In a survey of the available high resolution Viking Orbiter imagery, abundant fields of possible pseudocraters were found. However, only a small fraction of the plains forming units imaged at high resolution were found to contain the small cones. ...

Science.gov (United States)

Marine ecosystems are suffering severe depletion of apex predators worldwide; shark declines are principally due to conservative life-histories and fisheries overexploitation. On coral reefs, sharks are strongly interacting apex predators and play a key role in maintaining healthy reef ecosystems. Despite increasing fishing pressure, reef shark catches are rarely subject to specific limits, with management approaches typically depending upon no-take marine reserves to maintain populations. Here, we reveal that this approach is failing by documenting an ongoing collapse in two of the most abundant reef shark species on the Great Barrier Reef (Australia). We find an order of magnitude fewer sharks on fished reefs compared to no-entry management zones that encompass only 1% of reefs. No-take zones, which are more difficult to enforce than no-entry zones, offer almost no protection for shark populations. Population viability models of whitetip and gray reef sharks ...

Energy Technology Data Exchange (ETDEWEB)

An almost primordial trend in the conversion and use of energy is an increased complexity and cost of conversion systems designed to utilize cheaper and more-abundant fuels; this trend is exemplified by the progression fossil fission {yields} fusion. The present projections of the latter indicate that capital costs of the fusion ``burner`` far exceed any commensurate savings associated with the cheapest and most-abundant of fuels. These projections suggest competitive fusion power only if internal costs associate with the use of fossil or fission fuels emerge to make them either uneconomic, unacceptable, or both with respect to expensive fusion systems. This ``implementation-by-default`` plan for fusion is re-examined by identifying in general terms fusion power-plant embodiments that might compete favorably under conditions where internal costs (both economic and environmental) of fossil and/or fission are not as great as is needed to justify ...

CERN Document Server

Emission-line abundances have been uncertain for more than a decade due to unexplained discrepancies in the relative intensities of the forbidden lines and weak permitted recombination lines in planetary nebulae (PNe) and H II regions. The observed intensities of forbidden and recombination lines originating from the same parent ion differ from their theoretical values by factors of more than an order of magnitude in some of these nebulae. In this study we observe UV resonance line absorption in the central stars of PNe produced by the nebular gas, and from the same ions that emit optical forbidden lines. We then compare the derived absorption column densities with the emission measures determined from ground-based observations of the nebular forbidden lines. We find for our sample of PNe that the collisionally excited forbidden lines yield column densities that are in basic agreement with the column densities derived for the same ions from the UV absorption lines. ...

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 ...

Energy Technology Data Exchange (ETDEWEB)

We propose a novel method for ultrasensitive isotope analysis that combines magnetic mass selection, resonant charge-exchange neutralization, and resonant laser ionizaion. Our method attains high isotopic abundance selectivity by means of continuous multistage separation of ions stored in a small ring. For the environmentally interesting case of /sup 90/Sr versus /sup 88/Sr we estimate that sensitivity better than 10/sup -15/ for a throughput of 10/sup 13/ atoms/sec and an efficiency (after the ion source) greater than 10% are readily achievable.

DEFF Research Database (Denmark)

X-ray observations of the RSCVn system sigma Geminorum have been undertaken with the ROSAT observatory. Several spectra of very good signal-to-noise ratio were obtained. Spectral fitting using metal abundances amounting to 50% of solar values reveal two temperature components at 2 MK and 12 MK. Previous EXOSAT observations showed another component at 40 MK. Particular interest is focused on the temporal variations of the X-ray emission. It is found that variations occur on time scales ranging from years to hours and minutes.

Environmental Research Database

DescriptionThe nematophagous fungus, Pochonia chlamydosporia is a facultative parasite that has been developed through collaborative research between Rothamsted and the Centro Nacional de Sanidad Agropecuaria, Havana, Cuba, as the biocontrol agent Klamic against root-knot nematodes in tropical soils. The abundance of this fungus in soil is not necessarily related to its effectiveness as a biological control agent and its parasitic activity against nematode eggs is related to its nutrition and physiological [continued...

Energy Technology Data Exchange (ETDEWEB)

It becomes a cause of the air pollution by the generation of hydrogen chloride, when it is incinerated, when it decays, even if the plastic which becomes spent is buried. Every year, it is abundantly discharged and accumulates. Countries and enterprises, etc. carry out the examination for non-polluting processing and resource recycling of the waste plastic for material recycling and development by methods such as thermal recycling, practical application. In this paper, the following are examined: Plastic output and transition of the situation of the disposal quantity, resource recycling and problem. It wants to explain the challenge of more and more efficient resource recycling. (NEDO)

Energy Technology Data Exchange (ETDEWEB)

The fact that South Africa had no commercially significant deposits of crude oil necessitated the early development of production of gasoline from coal which was present in abundance in low to medium grade in thick seams, the development of the process since the early 1950s is discussed. Both the Fischer Tropsch and Lurgi processes are used, and three large plants named Sasol One, Two, and Three have been completed. A flow diagram for the Lurgi process as used in these plants is included. Typical products and their properties resulting from the Sasol-type Synthol operation are presented in tabular form. Marketing considerations and economics of production of the Sasol products are discussed briefly. (BLM)

International Nuclear Information System (INIS)

The components with masses 32 and 64M _s_u_n, evolved with the matter mixing in the semiconvective zone and filling their Roche lobes, after the main-sequence evolution overflow their Roche lobes and lose matter during the first part of the helium core burning. After the overflow end, the components lose the matter by stellar wind. The components shrink in the nuclear timescale. At first, they have the blue supergiant character with anomalous CNO abundance, then - the Wolf-Rayet stars character.

Energy Technology Data Exchange (ETDEWEB)

Florida posseses climatic, land, and water resources favorable for abundant biomass production. Therefore, a statewide program has been initiated to determine adapted species for the available array of production sites. Plant resources under investigation include woody, aquatic, grasses, hydrocarbon, and root crop species. The goal is to produce a continuous stream of biomass for the various biofuel conversion options. Preliminary yields from energy cropping experiments range from about 10 to nearly 90 metric tons per hectare per year, depending on the crop and the production systems employed. (Refs. 15).

Energy Technology Data Exchange (ETDEWEB)

DOE/NNSA and IRSN collaborated on a study of gamma-ray instruments and analysis methods used to perform isotopic measurements of special nuclear materials. The two agencies agreed to collaborate on the project in response to inconsistencies that were found in the various versions of software and hardware used to determine the isotopic abundances of uranium and plutonium. IRSN used software developed internally to test the MGA and FRAM isotopic analysis codes for criteria used to stop data acquisition. The stop-criterion test revealed several unusual behaviors in both the MGA and FRAM software codes.

International Nuclear Information System (INIS)

Published in summary form only.

International Nuclear Information System (INIS)

Short communication.

KoreaScience (Korea)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Abstract Not Provided

International Nuclear Information System (INIS)

... chemical reactions high temperature lattice parameters microhardness

International Nuclear Information System (INIS)

Short communication.

Czech Academy of Sciences Repository

Full Text Available

International Nuclear Information System (INIS)

Short communication.

KoreaScience (Korea)

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KoreaScience (Korea)

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KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

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International Nuclear Information System (INIS)

Production treatment chemicals represent a diverse collection of chemical classes, added at various points from the wellhead to the final flotation cell, to prevent operational upsets and enhance the separation of oil from water. Information in the literature indicates that while many treatment chemicals are thought to partition into oil and not into the produced water, there are cases where a sufficiently water soluble treatment chemical is added at high enough concentrations to suggest that the treatment chemical may add to the aquatic toxicity of the produced water. A study was conducted to evaluate the potential effect of production treatment chemicals on the toxicity of produced waters using the US EPA Seven-day Mysidopsis bahia Survival, Growth and Fecundity Test. Samples of produced water were collected and tested for toxicity from three platforms under ...

International Nuclear Information System (INIS)

Transformation of row material to the consumption goods proceeds by the succession of various technologies using energy and chemicals. Relative contribution of both factors is broadly varied. The chemical reagents are not per se consumption goods and their production is auxiliary. Maximal usage of chemicals is observed in conventional technologies. On the contrary radiation technology does not need chemicals. Therefore usage of radiation technology leads to diminution of chemical processing and hence to the attenuation of the technological press on the environment. As examples the radiation technological methods in conversion of coal and biomass are considered. (author).

International Nuclear Information System (INIS)

Due to the large number of chemicals in commerce without adequate toxicity characterization data, coupled with an ineffective federal policy for chemical management in the United States, many states are grappling with the challenge to identify toxic chemicals that may pose a risk to human health and the environment. Specific populations (e.g., children, elderly) are particularly sensitive to these toxic chemicals. In 2008, the Children's Safe Product Act (CSPA) was passed in Washington State. The CSPA included specific requirements to identify High Priority Chemicals (HPCs) and Chemicals of High Concern to Children (CHCCs). To implement this legislation, a methodology was developed to identify HPCs from authoritative scientific and regulatory sources on the basis of toxicity criteria. Another set of chemicals of concern was then identified ...

British Library Electronic Table of Contents (United Kingdom)

Summary Although risk assessments are typically conducted on a chemical-by-chemical basis, the 1996 Food Quality Protection Act required the US Environmental Protection Agency to consider cumulative risk of chemicals that act via a common mechanism of toxicity. To this end, we are conducting studies with mixtures of chemicals to elucidate mechanisms of joint action at the systemic level with the goal of providing a framework for assessing the cumulative effects of reproductive toxicants. Previous mixture studies conducted with antiandrogenic chemicals are reviewed briefly and two new studies are described. In all binary mixture studies, rats were dosed during pregnancy with chemicals, singly or in pairs, at dosage levels equivalent to approximately one-half of the ED50 for hypospadias or e...

Energy Technology Data Exchange (ETDEWEB)

This book examines some of the basic principles behind chemical reaction kinetics. Topics considered include the classical trajectory approach to reactive scattering; periodic orbits and theory of reactive scattering; and semiclassical reactive scattering.

Energy Technology Data Exchange (ETDEWEB)

This report summarizes the major activities conducted in the Chemical and Energy Research Section of the Chemical Technology Division (CTD) at Oak Ridge National Laboratory (ORNL) during the period January--March 1997. Created in March 1997 when the CTD Chemical Development and Energy Research sections were combined, the Chemical and Energy Research Section conducts basic and applied research and development in chemical engineering, applied chemistry, and bioprocessing, with an emphasis on energy-driven technologies and advanced chemical separations for nuclear and waste applications. The report describes the various tasks performed within seven major areas of research: Hot Cell Operations, Process Chemistry and Thermodynamics, Molten Salt Reactor Experiment (MSRE) Remediation Studies, Chemistry Research, Separations and Materials Synthesis, Solution ...

UK PubMed Central (United Kingdom)

Regulatory agencies currently rely on rodent carcinogenicity bioassay data to predict whether or not a given chemical poses a carcinogenic threat to humans. We argue that it is always more useful to...Full Text Available

Science.gov (United States)

This study investigated weathering effects on polyvinyl chloride (PVC) based wood plastic composites (WPC), with a focus on the color and structure that is attributed to the material composition. It is directed towards quantifying the main chemical modifi...

British Library Electronic Table of Contents (United Kingdom)

The effect of the water-chemical regime (WCR) on damage sustained by heating surfaces of steam generators at NPP is analyzed. It is indicated that phosphate treatment with minimal excesses of phosphates in the steamgenerator water is the most optimal method of managing the WCR regime of horizontal steam generators.

UK PubMed Central (United Kingdom)

A workshop on alternative toxicological testing methodologies was convened by the Scientific Group on Methodologies for the Safety Evaluation of Chemicals (SGOMSEC) 26-31 January 1997 in Ispra, Italy,...Full Text Available

UK PubMed Central (United Kingdom)

The mechanism by which mechanical force regulates the kinetics of a chemical reaction is unknown. Here, we use single-molecule force–clamp spectroscopy and protein engineering to study the effect...Full Text Available

Science.gov (United States)

Mineral scale formation in water distribution piping impedes flow, resulting in pressure and volume reduction and increasing operational costs. Chemical cleaning is both costly and time consuming, and there are health concerns when chemically cleaning pot...

UK PubMed Central (United Kingdom)

Lipopolysaccharides from different bacteria isolated from cotton were purified and chemically analyzed. Their pulmonary toxicity to animals was tested in inhalation tests. Lipopolysaccharides from Agrobacterium...Full Text Available

UK PubMed Central (United Kingdom)

The administration of chemicals at the maximum tolerated dose (MTD) in standard animal cancer tests is postulated to increase cell division (mitogenesis), which in turn increases rates of mutagenesis...Full Text Available

Science.gov (United States)

This project addresses the problem of flue gas desulfurization (FGD) sludge disposal to land. Specifically, the chemical species of FGD sludge constituents are thermodynamically modeled using the equilibrium constant approach, in an attempt to predict the constituent concentratio...

UK PubMed Central (United Kingdom)

Model systems to study the effects of chemicals of environmental concern on bacterial and parasitic diseases as well as the immunosurveillance and destruction of transplantable tumor cells were described...Full Text Available

Science.gov (United States)

Methods of acidizing a subterranean well formation, acidizing compositions, and sequestering additives for preventing the precipitation of metal compounds in the formation are described. Use of the methods and chemicals described should lead to improved formation permeability as compared to use of previous methods and chemicals. 12 claims.

British Library Electronic Table of Contents (United Kingdom)

Coal exploitation inevitably damages the natural ecological environment through large scale underground exploitation which exhausts the surrounding areas and is the cause of surface subsidence and cracks. These types of damage seriously lower the underground water table. Deterioration of the environment has certainly an impact on and limits growth of vegetation, which is a very important indicator of a healthy ecological system. Dynamically monitoring vegetation growth under coal exploitation stress by remote sensing technology provides advantages such as large scale coverage, high accuracy and abundant information. A scatter plot was built by a TM (Thematic Mapper) infrared and red bands. A detailed analysis of the distributional characteristics of vegetation pixels has been carried out. ...

International Nuclear Information System (INIS)

Modern civilisation is based on substantial utilisation of energy. Rapid industrial development and improvement of living standards in India require energy planners to adequately forecast the energy demand and take appropriate measures in advance. However, the development and establishment of new technology is a slow process, sometimes extending over decades. Hence, energy options based on new technologies need to be planned for much in advance making allowance for uncertainties and delays. Fast Breeder Reactor (FBR) technology is an advanced energy option promising abundant and economic supply of power. Research and development work on FBRs has been conducted at the Indira Gandhi Centre of Atomic Research (IGC) since 1971. The international trends in FBR development are highlighted in this discussion and an overview of some of the research activities at IGC is presented. (author). 8 refs., 7 tab s.

Science.gov (United States)

A new renicolid cercaria, Cercaria kuwaitae X sp. n., from the prosobranch gastropod Cerithium scabridum from Kuwait Bay is described. The new cercaria is nonstyleted gymnocephalous with voluminous Y-shaped excretory vesicle, flame cell formula 2[(3 + 3 + 3) + (3 + 3 + 3)] = 36, and without caudal fins. Surface topography of the new cercaria is studied by scanning electron microscopy. Domed papillae are abundant on the anterior and lateral aspects of the body, ciliated papillae are sparse dorsally. The ventral sucker bears nine domed papillae. Domed papillae form two circles around the oral sucker with three circles of spines in between. This is the first renicolid cercaria to be recorded in a gastropod from the Arabian Gulf region. PMID:9789783

British Library Electronic Table of Contents (United Kingdom)

Abstract The distribution and abundance of native ungulates were measured on commercially managed, semi arid rangeland in central Kenya over a 3 year period that encompassed severe drought and above average rainfall. Native ungulate biomass density averaged 5282 kg km 2 over the study and was dominated by elephant (Loxodonta africana), impala (Aepyceros melampus) and dik dik (Madoqua kirkii). Biomass density of domestic cattle (Bos taurus) averaged 2280 kg km 2 during the study. Responses of native ungulates to severe drought were variable. Impala densities were similar to or greater than densities for similar habitat in protected areas, and varied from 12 to 16 km 2 during and following the drought to 24 29 km 2 following above average rainfall. Dik dik densities were also greater than de...

British Library Electronic Table of Contents (United Kingdom)

Cancer cells recruit monocytes, macrophages and other inflammatory cells by producing abundant chemoattractants and growth factors, such as macrophage colony-stimulating factor (M-CSF/CSF-1) and monocyte chemoattractant protein-1 (MCP-1/CCL2), to promote tumor growth and dissemination. An understanding of the mechanisms that target cancer cells and regulate tumor microenvironment is essential in designing anticancer therapies. Here, we showed that serum amyloid-A (SAA) and cathelicidin (LL-37) stimulated M-CSF and MCP-1 expression with or without lipopolysaccharide (LPS) administration; conversely, lipoxin-A4 (LXA4) and annexin-A1 (ANXA1) inhibited LPS-induced M-CSF and MCP-1 production by human (HepG2) and mouse (H22) hepatocellular carcinoma cells (HCCs). The effects of LXA4, ANXA1, SAA ...

International Nuclear Information System (INIS)

The disrupted magnetic braking theory for the period gap of cataclysmic variable systems is used to study the binary evolution of low-mass main-sequence-like stars with white dwarf companions. The model is able to reproduce the observed location and width of the gap provided that the average mass transfer rates above the upper edge of the gap are greater than about 1.9 x 10 to the -9th solar masses/yr. For the case of angular momentum loss by magnetic braking, the slope of the mass transfer rate with respect to orbital period is shown to range from 3.4 to 3.7. For the evolutionary sequences considered, the He-3 abundance at the surface of the secondary exceeds 0.0015 after the complete mixing phase, resulting in modifications in the nuclear burning development of nova explosions. 31 refs.

International Nuclear Information System (INIS)

Nuclear astrophysics seeks for a possible explanation of the observed abundance distribution of various elements and their isotopes in the universe. Most of the relevant nuclear reactions take place in thermally equilibrium environments with bare nuclei, rather than accelerated and head-on colliding situations with low ionisation states of reactant atoms and molecules that are emulated in the laboratories. Moreover, the temperature of the astrophysical environments is quite often low compared to the centre-of-mass energy of the projectile nuclides, that is required for the reaction to be meaningfully investigated in the laboratory. Therefore, an extrapolation of the data on the reaction cross sections to very low energies and to extremely high density situations is generally called for, which are substantially altered every now and then for a number of astrophysically important reactions. The radioactive ion beams will provide us important data on some of those ...

Energy Technology Data Exchange (ETDEWEB)

Malaysia's petroleum industry is looking forward to an expansionary period until the end of the century, with the role of gas being greatly enhanced. The state oil firm Petronas sees increasing oil and gas reserves, making fuller use of abundant gas reserves, an exploration thrust into deepwater areas and the intensification of environmental protection as some of the points of emphasis in its current programme. The state firm president Tan Sri Datuk Azizan Zainul Abidin says that in the past few years a national economic growth rate of 8 percent has resulted in rising energy demand. Economic growth is projected to continue, so that an increase in power demand can be expected for the next few years. 'Fortunately, we are experiencing the same bullish trend in oil exploration and development,' he says. (author)

British Library Electronic Table of Contents (United Kingdom)

On six 400 m2 plots over 3 years, we excluded the sessile subduction and conveyer-belt feeding polychaete Arenicola marina which generates a pit-and-mound topography at the sediment surface from intertidal sands near the island of Sylt, Germany. This experiment was used to test whether other abundant deposit feeding polychaetes (the discretely motile and surface feeding ragworm Nereis diversicolor and the subsurface-feeding, motile orbiniid polychaete Scoloplos cf. armiger) benefit from competitive release. Ragworms took advantage from the absence of lugworms. Presumably they responded to a more stable and nutritious surface layer at lugworm exclusion plots (relief from inhibitive bioturbation). Contrary to this, S. cf. armiger was negatively affected by the exclusion of A. marina. It may ...

British Library Electronic Table of Contents (United Kingdom)

Surveys were carried out in 2006 and 2007 in Umbria (central Italy) to evaluate the presence of mycotoxigenic fungi and mycotoxins in maize grain sampled at harvest. Fusarium spp., were the most abundant species detected in maize kernels, followed by Aspergillus species of sections Flavi and Nigri and by Penicillium spp. Among Fusarium species, F. verticillioides was the most prevalent species, as detected by PCR directly on the kernels and on the fungi isolated from the kernels, followed by F. proliferatum and F. subglutinans. Fumonisins were the predominant mycotoxins with values, on average, of 4.3 and 5.7mgkg-1, in 2006 and 2007, respectively, with a maximum of 76.3mgkg-1 in the second year. Deoxynivalenol ranged from 0.2 to 3.98mgkg-1 in 2006 (average 1.04mgkg-1) and from undetectable...

British Library Electronic Table of Contents (United Kingdom)

Abstract The benthic marine worm Xenoturbella is frequently contaminated with molluscan DNA, which had earlier caused confusion resulting in a suggested bivalve relationship. In order to find the source of the contaminant, we have used molluscan sequences derived from Xenoturbella and compared them to barcodes obtained from several individuals of the nonmicroscopic molluscs sharing the same environment as Xenoturbella. Using cytochrome oxidase 1, we found the contaminating sequences to be 98% similar to the bivalve Ennucula tenuis. Using the highly variable D1-D2 region of the large ribosomal subunit in Xenoturbella, we found three distinct species of contaminating molluscs, one of which is 99% similar to the bivalve Abra nitida, one of the most abundant bivalves in the Gullmarsfjord where...

British Library Electronic Table of Contents (United Kingdom)

Through their grazing activities limpets have an important role in controlling macroalgal abundance and as a result the structure and dynamics of rocky shore assemblages. Using two congeneric limpet species, with different biogeographic distributions, and whose ranges are expected to alter with climatic warming, we separated the magnitude of their grazing activity over time and the subsequent consequence for macroalgal growth.The northern/boreal limpet, Patella vulgata (L.), consistently grazed more than the southern/lusitanian limpet, P. depressa (Pennant), particularly during spring and summer when P. depressa was reproductively active. Individuals of Fucus vesiculosus (L.) that settled during this time were able to grow to a size where they escaped the grazing activities of P. depressa,...

International Nuclear Information System (INIS)

The lower condition factors for two catfish species in water heated by effluents from APCo's Glen Lyn, Virginia plant as compared to control areas probably is not due to lack of food as evidenced by macroinvertebrate sampling and the fact that only 4.3 percent of the catfish stomachs were empty. Results suggested that young-of-the-year channel catfish were nonselectively eating food organisms present at both control and heated stations. The difference between stomach contents of flatheat catfish from the heated site and fauna available at that site indicated that fish were either moving out of the heated area to feed or were selectively feeding on organisms (particularly mayflies) which were in the substrate or drifted into the heated area. Stomach contents of the two species and distribution and abundance of the macroinvertebrate benthos community are detailed.

International Nuclear Information System (INIS)

Coir pith (CP), an abundantly available lignocellulosic agricultural waste from the local coir industry has been found to be an effective biosorbent for removal of metal ions from aqueous solutions. Transition metal hexacyanoferrates, in particular nickel hexacyano ferrate (NiHCF) also referred to as Prussian blue analogue (PBA), is known to be highly selective for removal of cesium from aqueous solutions. A novel method for the synthesis of PBA inside the porous matrix of coir pith and use of this composite material for the sorption of cesium is described in this paper. Equilibrium experiments showed that the sorption capacity of coir pith nearly doubled due to the modification. Owing to its low cost and rapid sorption kinetics, this hybrid material seems to be one of the most promising compounds for the recovery of cesium from liquid nuclear wastes. (author)

British Library Electronic Table of Contents (United Kingdom)

The earthworm gut provides ideal in situ conditions for ingested heterotrophic soil bacteria capable of anaerobiosis. High amounts of mucus- and plant-derived saccharides such as glucose are abundant in the earthworm alimentary canal, and high concentrations of molecular hydrogen (H2) and organic acids in the alimentary canal are indicative of ongoing fermentations. Thus, the central objective of this study was to resolve potential links between fermentations and active fermenters in gut content of the anecic earthworm Lumbricus terrestris by 16S ribosomal RNA (rRNA)-based stable isotope probing, with [13C]glucose as a model substrate. Glucose consumption in anoxic gut content microcosms was rapid and yielded soluble organic compounds (acetate, butyrate, formate, lactate, propionate, succi...

British Library Electronic Table of Contents (United Kingdom)

The treatment of Be-contaminated wastewater has been paid little attention, although beryllium (Be) and its compounds are of high toxicity. In this research, aerobic granule was for the first time introduced to remove Be from aqueous solution. Influencing factors including reaction time, initial Be concentration, pH, biosorbent dosage, and coexistent metal ions (Cd, Cu, and Fe) were investigated in batch experiments. The aerobic granule, characterized by element analysis and CLSM, was abundant in carboxyl, phosphoryl, amine and hydroxyl groups. Potentiometric titration experiment demonstrated that the pH effect on biosorption depended on the surface charge of granule (pHzpc=2.4) and the species of Be (Be^2^+, Be(OH)^+, and Be(OH)2) in solution. The coexistent metal ions would either inhibi...

Science.gov (United States)

We developed an intersection model to integrate parameters estimated from three distinct data sets that resulted from the Exxon Valdez oil spill: (1) the distribution, amount, and movements of spilled oil; (2) the distribution and abundance of sea otters along the Kenai Peninsula; and (3) the estimates of site-specific sea otter mortality relative to oil exposure from otters captured for rehabilitation and from collected carcasses. In this chapter, we describe the data sets and provide examples of how they can be used in the model to generate acute loss estimates. We also examine the assumptions required for the model and provide suggestions for improving and applying the model.

British Library Electronic Table of Contents (United Kingdom)

Beside yeasts, lactic acid bacteria (LAB) are the most abundant microbes in must during vinification. Whereas Oenococcos oeni is commercially used as a starter culture for the biological acid reduction in wines, other species are responsible for different types of wine spoilage. Members of the genera Pediococcus, Weissella, Leuconostoc, and Lactobacillus are producers of exopolysaccharide slimes, biogenic amines, acetic acid, and other off-flavors. In order to control microbial growth, different procedures such as heating of must and addition of sulfite or lysozyme from egg white are generally applied. Yet, because of health risks, the application of sulfite should be reduced and lysozyme is not effective against all LAB. In this study, we describe exoenzymes from a Streptomyces sp. strain...

International Nuclear Information System (INIS)

For better understanding and proper use of organic chemicals addition data are needed, including kinetic data on the scavenging reactions in actual cycles, data on ambient temperature stability and decomposition, sampling and analsyis information, data on effects in a case of fire, and more corrosion data. Use of these chemicals for layup of boilers and other equipment needs to be evaluated for each application. After a preliminary evaluation, such as outlined in this report, every new water treatment chemical should be evaluated in at least two month test in actual steam cycle. (orig.).

International Nuclear Information System (INIS)

... thermal power plants thermal reactors water cooled reactors WATER

KoreaScience (Korea)

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International Nuclear Information System (INIS)

... carrier-free isotopes chemical preparation gamma spectra isotope production

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

Several possibilities of the use of molecular models in quantum-chemical investigations of the structure of defect centers on the surfaces of oxides on nontransition elements have been illustrated. There has been a special discussion of the assumption of the local nature of the chemical interactions in these systems, which underlies such an approach, and of the consequent laws governing the formation of their lattices in the example cases of zeolites, kaolinites, and comparable boron- and aluminum-containing oxides. A quantum-chemical interpretation of the body of experimental data from investigations of the dehydroxylation of H forms of zeolites has been given. The structure of the Lewis acid centers formed as a result, and their chemisorption properties, have been discussed.

Energy Technology Data Exchange (ETDEWEB)

MINEQL is a subroutine package to calculate equilibrium composition of an aqueous system, accounting for mass transfer.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

The effects of variable hardness, pH, alkalinity, humics, and suspended clay on the chemical speciation of copper and its toxicity to fathead minnow larvae in Lake Superior water were investigated. Two proposed methods (toxicity factors and chemical speciation) for predicting LC50 values in specific natural waters from laboratory toxicity data and the average site specific values of general water quality parameters were evaluated. The accuracy of the cupric ion-selective electrode in determining CU/sup +2/ activities in ambient and chemically altered Lake Superior water was also determined.

Energy Technology Data Exchange (ETDEWEB)

Chemical effects of L X-ray intensity ratios in niobium and molybdenum compounds were studied by electron and proton bombardments. L{sub {gamma}1} X-rays which involve transition of 4d electrons of the valence shell were found to be sensitive to the chemical environment. The L{sub {gamma}1}/L{sub {beta}1} X-ray intensity ratio increased with an increase of the 4d electron occupation of niobium or molybdenum in niobium or molybdenum compounds, showing that the chemical effects can be ascribed to the 4d electron behavior of the metallic atom in its compounds. (orig.).

International Nuclear Information System (INIS)

A historical background is first given in which the role of biomass is described in relation to its competition with fossil biomass for the production of chemicals and energy. Occurrences of reserves from both sources are then compared. Petrochemical and biomass routes are then analyzed in terms of their relative competitive advantages. The oleochemical and biotechnology cases are analyzed in more detail as examples of biomass utilization. Latin American examples of industrial manufacturing of biomass derived chemicals are then provided. Alcochemicals are analyzed in detail as well as essential oils and other chemicals. Finally, references are made to regional Latin American initiatives regarding biomass and the objectives, organization and nature of the initiative are presented.

Science.gov (United States)

The chemical analysis of lipids of Prochloron isolated from several hosts is discussed. The object

Energy Technology Data Exchange (ETDEWEB)

This book examines some of the basic principles behind chemical reactions kinetics. Topics considered include ab initio determination of potential energy for chemical reactions; semi-empirical potential energy surfaces; general theory of reactive scattering: different equation approach; and integral equation approach to reactive scattering.

Science.gov (United States)

This request is submitted to seek interim approval to operate a Toxic Substances Control Act (TSCA) of 1976 chemical waste landfill for the disposal of polychlorinated biphenyl (PCB) waste. Operation of a chemical waste landfill for disposal of PCB waste ...

International Nuclear Information System (INIS)

X-ray scattering methods suitable for the investigation of the morphology and chemical composition of self-organized quantum dots and quantum wires are reviewed. Their application is demonstrated in experimental examples showing that a combination of small angle X-ray scattering with high-resolution X-ray diffraction can reveal both the shape and the chemical composition of the self-organized objects. (author)

Energy Technology Data Exchange (ETDEWEB)

Occupational and environmental exposure to organic ligands, solvents, fuel hydrocarbons, and polychlorinated biphenyls are linked with increased risk of hematologic malignancies. DOE facilities and waste sites in the U.S. are contaminated with mixtures of potentially hazardous chemicals such as metals, organic ligands, solvents, fuel hydrocarbons, polychlorinated biphenyls and radioactive isotopes. A major goal of this project was to establish linkage between chemical/radiation exposure and induction of genomic damage in target populations with the capability to undergo transformation.

Energy Technology Data Exchange (ETDEWEB)

This book deals specifically with the development of new processes of converting coal into useful chemical feedstocks. The major topic in this volume is the generation of syngas and its catalytic conversion to chemicals via the Fischer-Tropsch synthesis. Describes processes involved in conversion, recent catalytic developments, and the commercially important Sasol process. Also includes chapters on the carbide process and potential of future developments in the field.

International Nuclear Information System (INIS)

Chemical influences on the relative Ksub(#nu#)/Ksub(#alpha#) x-ray intensity ratio up to five per cent were found for different chemical constitutions of Cr, Mn, Fe and Cu by very precise PIXE measurements. In the discussion of these effects, screening of 3p electrons by a varying 3d valence charge, as well as polarisational effects are of importance. (author).

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Most chemical reactions in industry and biology are catalytic and play a role at some stage of the processing of about 80% of the goods manufactured in the U.S., yet catalysis is a neglected subject in chemical education. This book integrates the fragmentary treatment accorded the topic until now. It covers, in a unified way, catalysis in solutions, by enzymes, in synthetic polymers within the molecular scale cages of zeolites and other molecular sieves, and on surfaces of inorganic solids. The central ideas are chemical; and principles are illustrated by emphasizing industrial reactions and catalysts.

Energy Technology Data Exchange (ETDEWEB)

Many higher plants produce economically important organic compounds such as oils, resins, tannins, natural rubber, gums, waxes, dyes, flavors and fragrances, pharmaceuticals, and pesticides. However, most species of higher plants have never been described, much less surveyed for chemical or biologically active constituents, and new sources of commercially valuable materials remain to be discovered. Advances in biotechnology, particularly methods for culturing plants cells and tissues, should provide new means for the commercial processing of even rare plants and the chemicals they produce. These new technologies will extend and enhance the usefulness of plants as renewable resources of valuable chemicals. In the future, biologically active plant-derived chemicals can be expected to play an increasingly significant role in the commercial development of new products for regulating plant growth and for ...

International Nuclear Information System (INIS)

Severe depletion of nutrients through removal of the above ground litter caused a cessation of growth of a Eucalyptus exserta forest in tropical China. Since there is no above ground input of C in this forest, microbial biomass (C_m_i_c) and soil organic C (C_o_r_g) are maintained by the below ground input only. By determining the maintenance requirement of the soil microflora, it should be possible to estimate the below ground production of this forest. To check this hypothesis the authors performed an experiment with labelled C. Since large scale production and field application of "1"4C labelled Eucalyptus litter were not feasible, 'naturally labelled' C_4 plant litter (Zea mays) was used. Maize litter has a #delta#"1"3C of -12.7 per mille as compared with a #delta#"1"3C of -30.7 per mille for Eucalyptus leaf litter. The "1"3C abundance is used to determine the amount of maize C in each of the soil layers. Investigations were made of how supplementation of the ...

International Nuclear Information System (INIS)

New RNAA determinations of Ba, Sr, Zr, U, Re, Pd, Ag, Zn and Se and INAA measurements of Lu are added to published data for 21 other elements in the same suite of ten samples. On the average, 21 refractory elements are not significantly fractionated from one another. The mean of their enrichment factors relative to C1 chondrites is 17.5 +- 0.4, indicating that the high-temperature condensate inclusions represent 5.7 wt% of the total condensable matter. Os, Ir, Ru, Re and most of the W condensed in one or more refractory siderophile element alloys along with small fractions of the Pd, Co, Au and Ag. The bulk of the Eu and Sr condensed in solid solution in melilite. Sc, Zr, Hf, Ta, U and the remaining REE condensed in a phase whose abundance in the inclusions in negatively correlated with that of melilite, either diopside or one or more minor or trace phases, including perovskite. Ba condensed in a different phase, separately from all these elements. In individual ...

International Nuclear Information System (INIS)

The massive star-forming core MM1 of W75N was observed using the Submillimeter Array with #approx#1'' and 2'' spatial resolutions at 217 and 347 GHz, respectively. From the 217 GHz continuum we found that the MM1 core consists of two sources, separated by about 1'': MM1a (#approx#0.6 M_s_u_n) and MM1b (#approx#1.4 M_s_u_n), located near the radio continuum sources VLA 2/VLA 3 and VLA 1, respectively. Within MM1b, two gas clumps were found to be expanding away from VLA 1 at about #+-#3 km s"-"1, as a result of the most recent star formation activity in the region. Observed molecular lines show emission peaks at two positions, MM1a and MM1b: sulfur-bearing species have emission peaks toward MM1a, but methanol and saturated species at MM1b. We identified high-temperature (#approx#200 K) gas toward MM1a and the hot core in MM1b. This segregation may result from the evolution of the massive star-forming core. In the very early phase of star formation, the hot core is seen through the ...

Energy Technology Data Exchange (ETDEWEB)

The Gulf of California represents one of the most productive and unique marginal seas in the world. The mouth of the Gulf captures warm equatorial water while annual wind patterns assure major upwelling of nutrient-rich water leading to a rich marine biota. These conditions have created a wide array of tropical through warm temperate carbonate environments. The most unusual of these environments is located in the La Paz region of Baja California Sur where tropical-subtropical water temperatures and low rainfall have allowed growth of corals, calcareous red algae, and other shelled invertebrates to form a carbonate bank environment. Sampling and mapping transacts in shallow bays north of La Paz and on the adjacent Espiritu Santo island have revealed a full spectrum of subenvironments including mangrove bordered, terrigenous mud dominated coastal zones, which grade into carbonate tidal flats. In addition, single coral heads as well as incipient reef structures constructed by Porites and ...

International Nuclear Information System (INIS)

The use of environmental monitoring as a technique to identify activities related to the nuclear fuel cycle has been proposed by international safeguards organizations. The elements specific for each kind of nuclear activity, or 'nuclear signatures', inserted in the ecosystem can be intercepted by different live organisms. This work demonstrates the technical viability of using pine needles as bioindicators of nuclear signatures associated with uranium enrichment activities. Additionally, it proposes the use of HR-ICP-MS to identify the signature corresponding to that kind of activities in the ecosystem. Nitric acid solutions, used to wash pine needles sampled near nuclear facilities and containing only 0.1 #mu#g x kg"-"1 of uranium, exhibit a n("2"3"5U)/n("2"3"8U) isotopic abundance ratio of 0.0092#+-#0.0002, while solutions originated from samples collected at places located more than 200 km far from activities related to the nuclear fuel cycle exhibit a value of ...

Scientific Electronic Library Online (English)

Abstract in english The principal vector of malaria in eastern Venezuela, Anopheles aquasalis, is exophagic and exophilic. Control using indoor insecticide house sprays has failed to lower the number of malaria cases. Therefore, studies were initiated in two villages of the eastern coastal state of Sucre to better understand this vector's biology and develop a more integrated control program. An. aquasalis was found to have a crepuscular biting behavior with a major peak at dusk and a minor (more) peak at dawn. Mosquitos were collected more outdoors than indoors. Forty-seven percent of the biting took place before people went to bed (22:30 hr) and 69% of the mosquitos biting during this time period bite outdoors. Outdoor biting could be the reason why indoor spraying alone did not lower malaria cases. Seasonal abundance was greater in the rainy season compared to the dry season. Seasonal parous rates were high (78.3%-100%) and similar indoors and outdoors and ...

International Nuclear Information System (INIS)

We performed density functional calculations to examine the effects of solvation, hydrogen bonding, backbone conformation, and the side chain on 15N chemical shielding in proteins. We used N-methylacetamide (NMA) and N-formyl-alanyl-X (with X being one of the 19 naturally occurring amino acids excluding proline) as model systems. In addition, calculations were performed for selected fragments from protein GB3. The conducting polarizable continuum model was employed to include the effect of solvent in the density functional calculations. Our calculations for NMA show that the augmentation of the polarizable continuum model with the explicit water molecules in the first solvation shell has a significant influence on isotropic 15N chemical shift but not as much on the chemical shift anisotropy. The difference in the isotropic chemical shift between the standard ?-sheet and ?-helical conformations ranges ...

International Nuclear Information System (INIS)

Investigations were made on the biodegradability and bacterial toxicity of chemicals. The intention was to obtain data necessary for estimating and judging the behaviour of these chemicals during aerobic biological waste water treatment. The course of biodegradation and toxicity with time and concentration could be measured, quantified and described. As test procedure, the respirometric dilution method was used. This method is based on a die away test with continuous measuring of the oxygen used for biochemical oxidation processes. The course of the oxygen demand with time and concentration shows the biodegradation and toxicity patterns of the tested chemical. A variety of household and industrial chemicals were investigated. One group of substances were microbiocides, some of which showed toxic effects at concentrations less than 20 mg/l while others were biodegradable even at concentrations of 200 ...

Energy Technology Data Exchange (ETDEWEB)

Current information on the use of ionizing radiation for improving the storage of subtropical fruits like citrus, grapes, and avocados is reviewed. The feasibility of applying radiation either alone or in combination with other physical or chemical treatments for the control of postharvest fungal diseases is considered. Irradiation effects on the physiology of the fruits as related to respiration, ethylene evolution, changes in major chemical constituents, and quality are discussed. The recent trends in the possible use of irradiation as an alternative treatment to chemical fumigants for disinfestation of citrus and avocados and the prospects for the future application of irradiation for preservation of some of these fruits are outlined. 128 references.

Energy Technology Data Exchange (ETDEWEB)

Biosorption is an important removal mechanism in treating hydrophobic toxic organics in biological reactors. Equilibrium sorption isotherms and sorption kinetics of 2,4-dichlorophenol on live and chemically inactive anaerobic granules were studied. A metabolic inhibitor was used to inactivate the biological activity of the biomass. Results showed that the difference in the biosorption of live and chemically inactive anaerobic granules is not significant. This would suggest that anaerobic biosorption is mainly a physical-chemical process and that metabolic-mediated diffusion in the process is negligible. 12 refs., 3 tabs., 7 figs.

Energy Technology Data Exchange (ETDEWEB)

An independent chemical compatibility review of various wrapping and absorbent/padding materials was conducted to evaluate resistance to chemicals and constituents present in liquid waste from the Hanford underground tanks. These materials will be used to wrap long-length contaminated equipment when such equipment is removed from the tanks and prepared for transportation and subsequent disposal or storage. The materials studied were Cooley L18KU, Herculite, and Elephant Mat. The study concludes that these materials are appropriate for use in this application.

Energy Technology Data Exchange (ETDEWEB)

The Netherlands Chemical Industry Association (VNCI) is investigating the potential for expansion of the CHP capacity in the Dutch chemical industry. This report discusses the return on investment for CHP installations and the market conditions. Moreover, scenario results are presented for the CHP potential and the development of CHP in the chemical industry until 2020. [Dutch] De Vereniging van de Nederlandse Chemische Industrie (VNCI) heeft onderzoek laten uitvoeren om vast te stellen welke economische en beleidsmatige voorwaarden er zijn om het WKK-potentieel in de Nederlandse chemie te realiseren. Dit rapport brengt de marktpositie van WKK en de rentabiliteit van investeringen in WKK in beeld. Verder worden resultaten gegeven voor de potentiele energiebesparing en emissiereductie en wordt een scenario gepresenteerd voor het WKK-potentieel in de chemische industrie tot 2020.

Science.gov (United States)

... Chem. Res., in press, 2006. 8. Smith, BL, Bruno, TJ, Advanced distillation curve measurement with a model predictive temperature controller. Int. ...

UK PubMed Central (United Kingdom)

The protocols presently established for optimum seed storage do not account for the chemical composition of different seed species, the physiological status of the seed, and the physical status of water...Full Text Available

UK PubMed Central (United Kingdom)

The molecular structure, chemical properties, and biological function of the xyloglucan polysaccharide isolated from cell walls of suspension-cultured sycamore (Acer pseudoplatanus)...Full Text Available

International Nuclear Information System (INIS)

Portuguese Sep-Oct 1996 p. 571 Brazil Campos, Patricia Sao Paulo

Energy Technology Data Exchange (ETDEWEB)

The resistance to pitting of a Fe-17%Cr alloy in Cl[sup [minus

International Nuclear Information System (INIS)

The point at which the common final pathway for induction of cancer by chemical carcinogens and ionizing radiation has not been identified. Although common molecular targets are suggested by recent findings about the role of oncogenes, the mechanism by which the deposition of radiation energy and the formation of adducts or other DNA lesions induced by chemicals affects the changes in the relevant targets may be quite different. The damage to DNA that plays no part in the transformation events, but that influences the stability of the genome, and therefore, the probability of subsequent changes that influence tumorigenesis may be more readily induced by some agents than others. Similarly, the degree of cytotoxic effects that disrupt tissue integrity and increase the probability of expression of initiated cells may be dependent on the type of carcinogen. Also, evidence was presented that repair of the initial lesions could be demonstrated after ...

Science.gov (United States)

... explosive (shotgun shells, etc.) method of forming is being replaced--for the most part--by the electri- cal discharge and magnetic forming methods. ...

UK PubMed Central (United Kingdom)

BackgroundBisphenol A (BPA) is a high-production-volume chemical commonly used in the manufacture of polycarbonate plastic. Low-level concentrations of BPA in animals and possibly...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The OSHA's chemical occupational exposure standard for laboratories is an outgrowth of the previously issued Hazard Communication Standard. The standard relieves laboratories from complying with general industry standards but does not require compliance with specific guidelines. The heart of the standard is the creation of a Chemical Hygiene Plan (CHP) in every laboratory. The CHP addresses major issues such as safety equipment and procedures, work practices and training, the designation of a chemical hygiene officer, and the provision of medical consultation and examination for affected employees. This new standard, in effect as of 31 January, 1991, presents yet another regulatory challenge to laboratory managers but also will ensure a safer work environment for laboratory workers.

Science.gov (United States)

(NaMBT) inhibitor in ethylene glycol-water solutions. The improved method must be faster and more accur- ate than wet chemical techniques. ...

British Library Electronic Table of Contents (United Kingdom)

Vanadium carbide is the most effective grain growth inhibitor for ultrafine WC-Co composites due to its high solubility and mobility in the cobalt phase at relatively low temperatures; however, there are still some debates over the best way to introduce it into the WC-Co formulation. In this paper, the differences between admixed and chemically doped grain growth inhibitors on the microstructural development and properties of an ultrafine WC-10Co composite are discussed. The densification rate of chemically doped samples is slower in the early stage of sintering and the WC grain sizes of the sintered alloys are finer than those of admixed samples, leading to the increase of hardness and transverse rupture strength of the sintered alloys. The effectiveness of the chemically doped inhibitor ...

International Nuclear Information System (INIS)

... kinetics chemical reactions energy dependence ion-molecule collisions milli

International Nuclear Information System (INIS)

(Sep 1971). Japan Yokotsuka, Seiichiro Mitsubishi Chemical Industries, Ltd.,

UK PubMed Central (United Kingdom)

Insect growth regulators (IGRs) are a class of new chemicals that interfere with maturation and reproduction in insects. Proposed hypotheses on the biochemical mechanism of action are presented herein....Full Text Available

Science.gov (United States)

Accidents Accident Preparedness, Accident Prevention, Chemical Accidents, Radiation Accidents Characterization Contingency Plans National Contingency Plan (NCP), Oil Removal...

Science.gov (United States)

Accidents Accident Preparedness, Accident Prevention, Chemical Accidents, Radiation Accidents Characterization Contingency Plans National Contingency Plan (NCP), Oil Removal...

UK PubMed Central (United Kingdom)

The electrical responses of the neurons associated with the various types of chemosensory hairs of the blowfly, Phormia regina Meigen, following stimulation by chemical and mechanical...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A detailed chemical kinetic reaction mechanism is developed to describe incineration of the chemical warfare nerve agent sarin (GB), based on commonly used principles of bond additivity and hierarchical reaction mechanisms. The mechanism is based on previous kinetic models of organophosphorus compounds such as TMP, DMMP and DIMP that are often used as surrogates to predict incineration of GB. Kinetic models of the three surrogates and GB are then used to predict their consumption in a perfectly stirred reactor fueled by natural gas to simulate incineration of these chemicals. Computed results indicate that DIMP is the only one of these surrogates that adequately describes combustion of GB under comparable conditions. The kinetic pathways responsible for these differences in reactivity are identified and discussed. The most important reaction in GB and DIMP that makes them more reactive than TMP or DMMP is found to be a ...

Energy Technology Data Exchange (ETDEWEB)

The values of X = 0.77, Z = 0.035, and Y = 0.195 and the stage of evolution of Procyon are determined from the evolutionary tracks and the results of an analysis of the chemical composition of the atmosphere.

British Library Electronic Table of Contents (United Kingdom)

The influence of chemical and solvent extraction compatibilising techniques on the mechanical properties of poly-lactic acid (PLA) and MaterBi-polyester (PEM) based bio-composites are compared. First, fibres were chemically grafted with two fatty chains: stearic anhydride and octadecylisocyanate. Grafted fibres were characterised by FTIR and elemental analyses. Contact angle measurements show the hydrophobisation of the fibres in spite of very low surface grafting. Extracted and non-grafted fibres were prepared to be used as references. PEM and PLA-based composites with 30% w/w were prepared by compression moulding. Their mechanical properties were studied. It was found that chemical and solvent treatment of the fibres improved the reinforcement effect in the case of a PEM matrix and the Y...

Energy Technology Data Exchange (ETDEWEB)

Chemical characterization of passive films formed on AISI 304 austenitic stainless steel, in a borate/boric acid solution at pH 9.2, under various conditions of potential, temperature, and polarizations time, was made by Auger electron spectroscopy combined with ion sputtering, and x-ray photoelectron spectroscopy (XPS). The depth chemical composition, thickness, and duplex character of the passive layers were determined after processing AES sputter profiles by their quantitative approach based on the sequential layer sputtering model. Moreover, separated contributions of elements in their oxidized and unoxidized state could be disclosed from part to part of the oxide-alloy interface. The XPS study specified the chemical bondings which take placed inside the film, between Fe and oxygen (and water).

Science.gov (United States)

... On 20 March 1995, members from the religious cult Aum Shinrikyo released sarin and VX nerve gas into the Tokyo subway system. At the height of ...

Energy Technology Data Exchange (ETDEWEB)

A brief review of standard big bang nucleosynthesis theory and the related observations of the light element isotopes is presented. Implications of BBN on chemical evolution and constraints on particle properties will also be discussed.

Energy Technology Data Exchange (ETDEWEB)

An idea whose time has come takes center stage in London this week when BP Chemicals announces details of a consortium of chemical companies joining it in a new recycling project. In the project, which BP has been working on since 1989, waste plastic will be depolymerized to chemical feedstocks, via technology variously called feedstock or chemical recycling, polymer cracking, or tertiary recycling. BP's effort is one of the first to emerge from the research and pilot-plant stages that are committed to actual feedstock recycling of mixed polyolefins and other plastics. But it is only one of the many industry efforts under way to cope with the job of dealing with postconsumer plastics.

UK PubMed Central (United Kingdom)

Chemically reactive compounds in tissues can be monitored through their products of reaction with biomacromolecules. For the purpose of in vivo dose monitoring, hemoglobin (Hb) has been preferred to...Full Text Available

UK PubMed Central (United Kingdom)

We present a technique for identifying the amino acids responsible for a loss of immunoreactivity in response to treating an antigen with a chemical modifier. This is of particular interest...Full Text Available