WorldWideScience
1

Adrenaline modulates the global transcriptional profile of Salmonella revealing a role in the antimicrobial peptide and oxidative stress resistance responses  

UK PubMed Central (United Kingdom)

BackgroundThe successful interaction of bacterial pathogens with host tissues requires the sensing of specific chemical and physical cues. The human gut contains a huge number of...Full Text Available

2

Influence of Species Specificity and Other Factors on Bacteria Associated with the Coral Stylophora pistillata in Taiwan ?  

UK PubMed Central (United Kingdom)

Species of bacteria associated with Stylophora pistillata were determined by analyses of 16S ribosomal genes. Coral samples were taken from two distinct sites at Kenting, in the far...Full Text Available

2009-12-01

3

Host plant odor extracts with strong effects on oviposition behavior in Papilio polyxenes  

British Library Electronic Table of Contents (United Kingdom)

Abstract Ovipositing females of the black swallowtail butterfly, Papilio polyxenes Fabricius (Lepidoptera: Papilionidae: Papilioninae), have an innate response to contact chemical cues, but it was not known how naive females would respond to volatile host plant chemicals. Naive and experienced females were tested in a free-flight experiment using model plants and volatile extracts from two hosts, carrot [Daucus carota L. (Apiaceae)] and poison hemlock [Conium maculatum L. (Apiaceae)], and one non-host, fava bean [Vicia faba L. (Fabaceae)]. Naive females responded to both host plant extracts with more approaches and landings than to non-host extracts, with poison hemlock receiving more responses than carrot. Females experienced with one of the two host plants also approached and landed freq...

2008-01-01

4

Comparative analysis of nitrifying bacteria associated with freshwater and marine aquaria.  

UK PubMed Central (United Kingdom)

Three nucleic acid probes, two for autotrophic ammonia-oxidizing bacteria of the beta subdivision of the class Proteobacteria and one for alpha subdivision nitrite-oxidizing bacteria, were developed...Full Text Available

1996-08-01

5

Antimicrobial susceptibilities of bacteria associated with periodontal disease.  

UK PubMed Central (United Kingdom)

A total of 193 bacterial strains were tested for their susceptibilities to 14 antimicrobial agents. Penicillin G was active at 2 U/ml against 98% of the oral isolates. Other antibiotics with good activity...Full Text Available

1983-03-01

6

Subjective scaling of spatial room acoustic parameters influenced by visual environmental cues  

UK PubMed Central (United Kingdom)

Although there have been numerous studies investigating subjective spatial impression in rooms, only a few of those studies have addressed the influence of visual cues on the judgment of auditory measures....Full Text Available

2010-10-01

7

Bayesian Cue Integration as a Developmental Outcome of Reward Mediated Learning  

UK PubMed Central (United Kingdom)

Average human behavior in cue combination tasks is well predicted by Bayesian inference models. As this capability is acquired over developmental timescales, the question arises, how it is learned....Full Text Available

8

Operational Constraints on the Utility of Virtual Audio Cueing  

Science.gov (United States)

... conditions. the Air Force Research Laboratory's Aural Displays and The advent of virtual audio technology provides as many ...

1999-09-01

9

Spatial water maze learning using celestial cues by the meadow vole, Microtus pennsylvanicus.  

Science.gov (United States)

The Morris water maze is widely used to evaluate to evaluate the spatial learning ability of rodents under laboratory settings. The present study demonstrates that reproductive male meadow voles, Microtus pennsylvanicus, are able to acquire and retain a spatial water maze task using celestial cues. Voles were able to acquire a modified outdoor Morris water maze task over 4 trials per day, whereby they had to learn and remember the location of a submerged hidden platform, using the position of the sun and associated celestial cues. Their proficiency on this task was related to the availability of the celestial cues, with voles displaying significantly poorer spatial navigation on overcast than clear days and when the testing time (and position of the sun and associated celestial cues) was shifted from morning to afternoon. These findings with meadow voles support the ecological relevance of the water ...

1994-03-31

10

Filopodia  

UK PubMed Central (United Kingdom)

The processes of neuronal outgrowth and guidance have typically been studied in classic 2D cell culture systems that do not recapitulate topographical cues present in the in vivo extracellular matrix...Full Text Available

2011-07-01

11

Confidence-Based Performance Assessments for the BMDO ...  

Science.gov (United States)

... Notes Papers from the Proceedings AIAA 2nd Biennial ... Based (GB) Lower Tier Weapon System clearly ... are too short for space-based cueing to be ...

2001-03-27

12

2011 Critical Use Exemption Nominations from the Phaseout of...  

Science.gov (United States)

transmitted to the Ozone Secretariat of the United Nations Environment Programme (UNEP) its sixth nomination for a critical use exemption (CUE) from the phaseout of methyl...

2011-02-08

13

Proteomic Profiling of Mesenchymal Stem Cell Responses to Mechanical Strain and TGF-B1  

Energy Technology Data Exchange (ETDEWEB)

Mesenchymal stem cells (MSCs) are a potential source of smooth muscle cells (SMCs) for constructing tissue-engineered vascular grafts. However, the details of how specific combinations of vascular microenvironmental factors regulate MSCs are not well understood. Previous studies have suggested that both mechanical stimulation with uniaxial cyclic strain and chemical stimulation with transforming growth factor {beta}1 (TGF-{beta}1) can induce smooth muscle markers in MSCs. In this study, we investigated the combined effects of uniaxial cyclic strain and TGF-{beta}1 stimulation on MSCs. By using a proteomic analysis, we found differential regulation of several proteins and genes, such as the up-regulation of TGF-{beta}1-induced protein ig-h3 (BGH3) protein levels by TGF-{beta}1 and up-regulation of calponin 3 protein level by cyclic strain. At the gene expression level, BGH3 was induced by TGF-{beta}1, but calponin 3 was not significantly regulated by mechanical ...

2009-10-12

14

Visually Mediated Odor Tracking During Flight in Drosophila  

UK PubMed Central (United Kingdom)

Flying insects use visual cues to stabilize their heading in a wind stream. Many animals additionally track odors carried in the wind. As such, visual stabilization of upwind tracking directly aids...Full Text Available

15

Transcriptional coactivator PGC-1? promotes peroxisomal remodeling and biogenesis  

UK PubMed Central (United Kingdom)

Mitochondria and peroxisomes execute some analogous, nonredundant functions including fatty acid oxidation and detoxification of reactive oxygen species, and, in response to select metabolic cues, undergo...Full Text Available

2010-11-23

16

Sonic hedgehog controls growth of external genitalia by regulating cell cycle kinetics  

UK PubMed Central (United Kingdom)

During embryonic development, cells are instructed which position to occupy, they interpret these cues as differentiation programmes, and expand these patterns by growth. Sonic hedgehog...Full Text Available

2010-06-01

17

Perceived association between diagnostic and non-diagnostic cues of women's sexual interest: General Recognition Theory predictors of risk for sexual coercion  

UK PubMed Central (United Kingdom)

Young men's errors in sexual perception have been linked to sexual coercion. The current investigation sought to explicate the perceptual and decisional sources of these social perception errors,...Full Text Available

2010-01-01

18

OLFACTORY CUES ARE SUFFICIENT TO ELICIT SOCIAL APPROACH BEHAVIORS BUT NOT SOCIAL TRANSMISSION OF FOOD PREFERENCE IN C57BL/6J MICE  

UK PubMed Central (United Kingdom)

Mouse models for the study of autistic-like behaviors are increasingly needed to test hypotheses about the causes of autism, and to evaluate potential treatments. Both the automated 3-chambered...Full Text Available

2008-11-21

19

Muscle satellite cell proliferation and association: new insights from myofiber time-lapse imaging  

UK PubMed Central (United Kingdom)

BackgroundAs the resident stem cells of skeletal muscle, satellite cells are activated by extracellular cues associated with local damage. Once activated, satellite cells will re-enter...Full Text Available

20

Making simple sentences hard: Verb bias effects in simple direct object sentences  

UK PubMed Central (United Kingdom)

Constraint-based lexical models of language processing assume that readers resolve temporary ambiguities by relying on a variety of cues, including particular knowledge of how verbs combine...Full Text Available

2009-04-01

21

Impaired Perinatal Growth and Longevity: A Life History Perspective  

UK PubMed Central (United Kingdom)

Life history theory proposes that early-life cues induce highly integrated responses in traits associated with energy partitioning, maturation, reproduction, and aging such that the individual phenotype...Full Text Available

2009-01-01

22

EphB Receptors Couple Dendritic Filopodia Motility to Synapse Formation  

UK PubMed Central (United Kingdom)

SUMMARYMotile dendritic filopodial processes are thought to be precursors of spine synapses, but how motility relates to cell-surface cues required for axon-dendrite recognition...Full Text Available

2008-07-10

23

EARLY FLOWERING3 Encodes a Novel Protein That Regulates Circadian Clock Function and Flowering in Arabidopsis  

UK PubMed Central (United Kingdom)

Higher plants use photoperiodic cues to regulate many aspects of development, including the transition from vegetative to floral development. The EARLY FLOWERING3 (ELF3)...Full Text Available

2001-06-01

24

Clarifying the Factors that Undermine Behavioral Inhibition System Functioning in Psychopathy  

UK PubMed Central (United Kingdom)

Psychopathic individuals are generally unresponsive to motivational and emotional cues that facilitate behavioral regulation. A putative mechanism for this deficiency is Gray’s (1971)...Full Text Available

2010-10-01

25

Analysis of the astray/robo2 zebrafish mutant reveals that degenerating tracts do not provide strong guidance cues for regenerating optic axons  

UK PubMed Central (United Kingdom)

During formation of the optic projection in astray/robo2 mutant zebrafish, optic axons exhibit rostro-caudal pathfinding errors, ectopic midline crossing and...Full Text Available

2010-10-13

26

Aging of the Hair Follicle Pigmentation System  

UK PubMed Central (United Kingdom)

Skin and hair phenotypes are powerful cues in human communication. They impart much information, not least about our racial, ethnic, health, gender and age status. In the case of the latter parameter,...Full Text Available

2009-07-01

27

Adaptive plasticity of mammalian sperm production in response to social experience  

UK PubMed Central (United Kingdom)

Sperm competition theory predicts that males should invest prudently in ejaculates according to levels of female promiscuity. Males may therefore be sensitive to cues in their social environment associated...Full Text Available

2009-02-22

28

Episodic Future Thinking Reduces Reward Delay Discounting through an Enhancement of Prefrontal-Mediotemporal Interactions  

British Library Electronic Table of Contents (United Kingdom)

Summary Humans discount the value of future rewards over time. Here we show using functional magnetic resonance imaging (fMRI) and neural coupling analyses that episodic future thinking reduces the rate of delay discounting through a modulation of neural decision-making and episodic future thinking networks. In addition to a standard control condition, real subject-specific episodic event cues were presented during a delay discounting task. Spontaneous episodic imagery during cue processing predicted how much subjects changed their preferences toward more future-minded choice behavior. Neural valuation signals in the anterior cingulate cortex and functional coupling of this region with hippocampus and amygdala predicted the degree to which future thinking modulated individual preference fu...

2010-01-01

29

The mGluR2 Positive Allosteric Modulator BINA Decreases Cocaine Self-Administration and Cue-Induced Cocaine-Seeking and Counteracts Cocaine-Induced Enhancement of Brain Reward Function in Rats  

UK PubMed Central (United Kingdom)

Metabotropic glutamate receptor 2/3 (mGluR2/3) agonists were shown previously to nonselectively decrease both cocaine- and food-maintained responding in rats. mGluR2 positive allosteric modulators (PAMs)...Full Text Available

2010-09-01

30

Lesions that functionally disconnect the anterior and posterodorsal sub-regions of the medial amygdala eliminate opposite-sex odor preference in male Syrian hamsters (Mesocricetus auratus)  

UK PubMed Central (United Kingdom)

In many rodent species, such as Syrian hamsters, reproductive behavior requires neural integration of chemosensory information and steroid hormone cues. The medial amygdala processes both of...Full Text Available

2010-02-17

31

Contextual extracellular cues promote tumor cell EMT and metastasis by regulating miR-200 family expression  

UK PubMed Central (United Kingdom)

Metastatic disease is a primary cause of cancer-related death, and factors governing tumor cell metastasis have not been fully elucidated. Here, we address this question by using tumor cell lines derived...Full Text Available

2009-09-15

32

Behavioral Stress May Increase the Rewarding Valence of Cocaine-Associated Cues Through a Dynorphin/?-Opioid Receptor-Mediated Mechanism without Affecting Associative Learning or Memory Retrieval Mechanisms  

UK PubMed Central (United Kingdom)

Stress exposure increases the risk of addictive drug use in human and animal models of drug addiction by mechanisms that are not completely understood. Mice subjected to repeated forced swim stress...Full Text Available

2010-08-01

33

A volume formula for hyperbolic tetrahedra in terms of edge lengths  

CERN Document Server

We give a closed formula for volumes of generic hyperbolic tetrahedra in terms of edge lengths. The cue of our formula is by the volume conjecture for the Turaev-Viro invariant of closed 3-manifolds, which is defined from the quantum 6j-symbols. This formula contains the dilogarithm functions, and we specify the adequate branch to get the actual value of the volumes.

2004-01-01

34

Turbulence Investigation and Reproduction for Assisting Downstream Migrating Juvenile Salmonids, Part II of II; Effects of Induced Turbulence on Behavior of Juvenile Salmon, 2001-2005 Final Report.  

Energy Technology Data Exchange (ETDEWEB)

Passage through dams is a major source of mortality of anadromous juvenile salmonids because some populations must negotiate up to eight dams in Columbia and Snake rivers. Dams cause direct mortality when fish pass through turbines, but dams may also cause indirect mortality by altering migration conditions in rivers. Forebays immediately upstream of dams have decreased the water velocity of rivers and may contribute substantially to the total migration delay of juvenile salmonids. Recently, Coutant (2001a) suggested that in addition to low water velocities, lack of natural turbulence may contribute to migration delay by causing fish to lose directional cues. Coutant (2001a) further hypothesized that restoring turbulence in dam forebays may reduce migration delay by providing directional cues that allow fish to find passage routes more quickly (Coutant 2001a). Although field experiments have yielded proof of the concept of using induced ...

2005-07-01

35

Nonhuman primates will not respond to turn off strong 60 Hz electric fields  

Energy Technology Data Exchange (ETDEWEB)

Using a set of six baboons (Papio cynocephalus), the authors conducted a series of seven experiments designed to evaluate the potentially aversive character of a 60 Hz electric field (EF). Initially, the subjects were trained, using food rewards as the reinforcer, to respond only when a cue light was illuminated. Next, an EF was presented along with the cue light; responses produced delivery of a food pellet and turned off both the cue light and the EF. Then, stimulus and reward conditions were varied. The authors determined that (1) presence of a strong EF does not affect operant responding for food rewards, (2) subjects will not respond at normal rates when the only reinforcer is termination of a strong EF, (3) presence of a strong EF can serve as a discriminative stimulus, (4) presence of a strong EF does not affect extinction of an appetite-motivated task, and (5) presentation of an EF can become a secondary reinforcer. ...

1995-12-31

36

Microbiological Comparison of Core and Groundwater Samples Collected from a Fractured Basalt Aquifier with that of Dialysis Chamber Incubated in Situ  

Energy Technology Data Exchange (ETDEWEB)

Microorganisms associated with fractured basalt core were compared to those suspended in groundwater pumped from the same well in the eastern Snake River Plain Aquifer (Idaho, USA). Two wells influenced to different degrees by a mixed-waste plume in the fractured basalt aquifer were examined. In one well, an array of dialysis cells filled with either deionized water or crushed basalt was equilibrated to compare the microorganisms collected in this fashion with those from core and groundwater samples collected in a traditional manner from the same well. Analyses were performed to characterize these samples and to provide a basis for comparison. These included total cell counts by microscopy; total biomass by phospholipid fatty acid analysis; enumerations of viable aerobic heterotrophs, groups of putative aerobic co-metabolic TCE-degraders and aerobic H2-oxidizing bacteria; mineralization of 14C- labeled acetate; and enrichments for dissimilatory iron-reducing bacteria. The 16S rDNA ...

2004-04-01

37

Industrial Technologies Program: Chemicals  

Science.gov (United States)

Efficiency and Renewable Energy EERE Home | Programs & Offices | Consumer Information Chemicals Search Search Help Chemicals EERE » Industrial Technologies Program » Chemicals...

2011-10-01

38

Risk of sperm competition does not influence copulatory behavior in the promiscuous meadow vole (Microtus pennsylvanicus)  

British Library Electronic Table of Contents (United Kingdom)

It is not clear whether males in all mammalian species adjust their copulatory behavior when faced with risk of sperm competition (RSC). Previous work on meadow voles, Microtus pennsylvanicus, indicated that males increase their sperm expenditure but not the number of ejaculations in the presence of odors of a conspecific male. The present study follows up on this work and asks whether male meadow voles modify any aspect of their copulatory behavior when they face a RSC. We examined 46 variables of copulatory behavior and found that the presence of odors from a conspecific male did not affect any of these variables. Thus, male meadow voles, unlike some other species of mammals, do not adjust their copulatory behavior when exposed to cues associated with an elevated RSC.

2007-01-01

39

Musicians demonstrate experience-dependent brainstem enhancement of musical scale features within continuously gliding pitch  

British Library Electronic Table of Contents (United Kingdom)

In contrast to language, where pitch patterns consist of continuous and curvilinear contours, musical pitch consists of relatively discrete, stair-stepped sequences of notes. Behavioral and neurophysiological studies suggest that both tone-language and music experience enhance the representation of pitch cues associated with a listener's domain of expertise, e.g., curvilinear pitch in language, discrete scale steps in music. We compared brainstem frequency-following responses (FFRs) of English-speaking musicians (musical pitch experience) and native speakers of Mandarin Chinese (linguistic pitch experience) elicited by rising and falling tonal sweeps that are exemplary of Mandarin tonal contours but uncharacteristic of the pitch patterns typically found in music. In spite of musicians' unf...

2011-01-01

40

Making Simple Sentences Hard: Verb Bias Effects in Simple Direct Object Sentences  

Science.gov (United States)

Constraint-based lexical models of language processing assume that readers resolve temporary ambiguities by relying on a variety of cues, including particular knowledge of how verbs combine with nouns. Previous experiments have demonstrated verb bias effects only in structurally complex sentences, and have been criticized on the grounds that such effects could be due to a rapid reanalysis stage in a two-stage modular processing system. In a self-paced reading experiment and an eyetracking experiment, we demonstrate verb bias effects in sentences with simple structures that should require no reanalysis, and thus provide evidence that the combinatorial properties of individual words influence the earliest stages of sentence comprehension. (Contains 4 figures and 12 tables.)

2009-04-01

41

Discriminating Males and Unpredictable Females: Males Bias Sperm Allocation in Favor of Virgin Females  

British Library Electronic Table of Contents (United Kingdom)

Abstract When both sexes mate with multiple partners, theory predicts that males should adjust their investment in ejaculates in response to the risk and/or intensity of sperm competition. Here, we demonstrate that, in the harlequin beetle riding pseudoscorpion, Cordylochernes scorpioides, males use cues deposited on females by previous males to distinguish between virgin, once-mated, and multiply-mated females and adjust sperm allocation accordingly. Sperm number declined in direct proportion to the number of previous males, with virgin females receiving nearly three times more sperm than females exposed to three previous males. Given the lack of first-male sperm precedence in C.scorpioides, this pattern is not consistent with current sperm competition models and appears best explained by...

2011-01-01

42

Comparison of auditory sense organs in parasitoid Tachinidae (Diptera) hosted by Tettigoniidae (Orthoptera) and homologous structures in a non-hearing Phoridae (Diptera)  

British Library Electronic Table of Contents (United Kingdom)

The dipteran parasitoids Therobia leonidei and Homotrixa alleni (Tachinidae) use acoustic cues to locate their calling tettigoniid (Ensifera, Orthoptera) hosts. The sexually dimorphic tympanal organs of both fly species are located at the prosternum. For comparison a homologous chordotonal organ in the non-hearing fly Phormia regina, Meigen (Phoridae) is also described. The scolopidial sense organs of the ears have approximately 180 sensory cells in Th. leonidei and 250 cells in H. alleni. Interspecific analysis indicates that the cell number and arrangement might be genus specific in Tachinidae. The mononematic scolopidia, each with one sensory cell, are of different sizes and insert at the tympanal membrane. Large scolopidial units (diameter of sensory cells up to 50??m) extend longitudi...

2007-01-01

43

Change in number and activation of androgen receptor-immunoreactive cells in the medial amygdala in response to chemosensory input  

British Library Electronic Table of Contents (United Kingdom)

In many species social behaviors are dependent on integration of chemosensory and hormonal cues. Many chemosensory stimuli are detected by the vomeronasal organ, which projects to many regions that contain steroid receptors, including the medial amygdala. In male hamsters, testosterone is known to acutely increase in response to chemosensory stimulation, and can facilitate sexual behavior by direct action within the medial amygdala. Conspecific stimuli activate the anterior (MeA) and posterior (MeP) medial amygdala, while heterospecific stimuli activate only MeA. Chemosensory stimuli with different social significance differentially activate the dorsal and ventral subdivisions of MeA and MeP. Therefore, it is likely that steroids differentially facilitate stimulation of the medial amygdala...

2011-01-01

44

Afferent mechanisms of microwave-induced biological effects. Annual report, 1 June 1985-31 May 1986  

Energy Technology Data Exchange (ETDEWEB)

Effects of 2450-MHz circularly polarized microwave irradiation on central nervous system functions were studied. Pulsed (microsecond, 500 pps) microwaves decreased high-affinity sodium-dependent choline uptake in the hippocampus and frontal cortex of the rat. The effect on hippocampal choline uptake was blocked by pretreatment with narcotic antagonists. Continuous-wave microwaves of the same power density decreased choline uptake in the frontal cortex only. Furthermore, it was found that the effects of pulsed microwaves on central cholinergic activity are classically conditionable to cues in the exposure environment. The hypothesis that some of the neurological effects of pulsed microwave irradiation are caused by its effect on the auditory system was investigated. Effects of pink noise and pulsed microwaves were compared.

1986-07-01

45

Chemical Reactor Diagnostics  

International Science & Technology Center (ISTC)

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

46

Chemical Emergencies  

Medline Plus

English - Chemical Emergencies Click to Stop Video Click to Start Video To Listen to the Audio or ...

47

Influence of gonadal hormones on odours emitted by male meadow voles (Microtus pennsylvanicus).  

Science.gov (United States)

Free-living male meadow voles (Microtus pennsylvanicus) emit odours that are attractive to females at the beginning, but not at the end, of the breeding season. The effect of gonadal hormones on female-attractant cues was examined in males born and reared in long (14 h light day-1) and short (10 h light day-1) photoperiods that simulate daylengths in the breeding and nonbreeding seasons, respectively. Gonadectomy affected the attractant properties of odours emitted by long photoperiod, but not short photoperiod, males. Long photoperiod females preferred odours of intact rather than those of gonadectomized long photoperiod males, and odours of gonadectomized long photoperiod males rather than those of intact short photoperiod males. Females did not show a preference between the odours of intact and castrated short photoperiod males. Gonadal hormone replacement in males affected female responses to the odours emitted by long photoperiod, but not short photoperiod, ...

1992-08-01

48

Prediction of Chemicals Ecotoxicity  

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

49

Cell proliferation and chemical carcinogenesis: symposium overview.  

UK PubMed Central (United Kingdom)

Cancer, by definition, is a proliferative disease. The fundamental scientific issue explored at the international symposium "Cell Proliferation and Chemical Carcinogenesis" was the impact of chemically...Full Text Available

1993-12-01

50

CHEMICAL LEUCODERMA: INDIAN SCENARIO, PROGNOSIS, AND TREATMENT  

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

2010-07-01

61

Massage Therapy  

Medline Plus

... Massage therapy can help the body release certain chemicals. These chemicals help us relax, improve blood circulation and get ...

62

Time course of androgenic modulation of odor preferences and odor cues in male meadow voles, Microtus pennsylvanicus.  

Science.gov (United States)

During the breeding season, male meadow voles prefer female over male odors and females prefer male over female odors. Testosterone control of males' odor preferences and production of odors attractive to females differ. A male meadow vole's preference for female versus male odor was still evident 1 week after castration, but not 1 week later. This preference was reinstated in testosterone-treated male voles 2 weeks after the onset of hormone replacement. The attractiveness of male odors to females did not disappear until 3 weeks after castration. The attractiveness of male odors was reinstated 1 week after castrated males were treated with testosterone. The time course for the androgenic modulation of production of odors attractive to females may facilitate breeding. For example, at the end of the breeding season males may emit an odor that is still attractive to females. Similarly, at the beginning of the breeding season males may emit an odor that is attractive to females. ...

1992-12-01

63

Representation of uncertainty in computer vision using fuzzy sets  

Energy Technology Data Exchange (ETDEWEB)

Uncertainty in computer vision can arise at various levels. It can occur in the low level in the raw sensor input, and extends all the way through intermediate and higher levels. Ideally, at any level where decisions are being made on the basis of previous processing steps, a computer vision system must have sufficient flexibility for representation of uncertainty in any of these levels. The input cue representation portion of a computer vision system should maintain the information content of the original input images, while at the same time allowing for uncertainty in the identification of attributes required by other parts of the system for decision making. Processes such as edge detection, segmentation, and shape matching yield results which could bias higher level decision making, unless some framework is defined for the representation of uncertainty in the context of fuzzy set theory where membership values associated with the fuzzy sets contain a consistent ...

1986-02-01

64

Effects of low-level microwave irradiation on hippocampal and frontal cortical choline uptake are classically conditionable  

Energy Technology Data Exchange (ETDEWEB)

In previous research, we found that sodium-dependent high-affinity choline uptake in the hippocampus and frontal cortex of the rat was lowered after acute (45 min) exposure to low-level 2450-MHz pulsed microwaves (power density 1 mW/cm2; average whole body specific absorption rate, 0.6 W/kg; 2 mu sec pulses, 500 pps). In the present experiment, we investigated developments of tolerance and classical conditioning to these effects of microwaves. Rats were exposed to microwaves in cylindrical waveguides in 10 daily sessions (45 min per session). In an 11th session, we subjected the rats to either microwave (study of tolerance) or sham exposure (study of conditioned effect) for 45 min, and immediately measured choline uptake in the hippocampus and frontal cortex. We found that tolerance, a decrease in response to microwaves, developed to the effect of microwaves on choline uptake in the hippocampus, but not in the frontal cortex. Conditioned effects were also observed: an increase in ...

1987-08-01

65

Behavioral effects of microwaves  

Energy Technology Data Exchange (ETDEWEB)

Microwaves can produce sensations of warmth and sound in humans. In other species, they also can serve as cues, they may be avoided, and they can disrupt ongoing behavior. These actions appear to be due to heat produced by energy absorption. The rate of absorption depends on the microwave parameters and the electrical and geometric properties of the subject. We therefore, cannot predict the human response to microwaves based on data from other animals without appropriate scaling considerations. At low levels of exposure, microwaves can produce changes in behavior without large, or even measureable, changes in body temperature. Thermoregulatory behavior may respond to those low levels of heat, and thereby affect other behavior occurring concurrently. There are no data that demonstrate that behavioral effects of microwaves depend on any mechanism other than reactions to heat. Our interpretation of whether a reported behavioral effect indicates that microwaves may be ...

1980-01-01

66

Laboratory evaluation of the feasibility of chemical oxidation processes for treatment of contaminated groundwaters. Final report  

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).

1995-09-01

67

Coatings with controlled porosity and chemical properties  

Energy Technology Data Exchange (ETDEWEB)

Coatings and sensors having both steric and chemical selectivity. Controlled porosity provides the steric selectivity, whereas chemically tailored film properties, using controlled composition or modification by coupling agents, chemical species replacement, or chemical species within pores, provide the chemical selectivity. Single or multiple layers may be provided.

1996-01-01

68

Star-formation triggers and chemical evolution  

Energy Technology Data Exchange (ETDEWEB)

Comparative studies of flocculent and grand-design spirals suggest that density waves are not the predominant trigger of star formation in most galaxies. Implications for chemical evolution are profound. It may be possible to ignore the details of the spiral-wave phenomenon in research aimed at unifying the chemical properties of spiral disks. 16 references.

1986-10-01

69

Low-Level Exposure to Multiple Chemicals: Reason for Human Health Concerns?  

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

2007-12-01

70

Interactive Toxicity of Inorganic Mercury and Trichloroethylene in Rat and Human Proximal Tubules  

UK PubMed Central (United Kingdom)

Simultaneous or prior exposure to one chemical may alter the concurrent or subsequent response to another chemical, often in unexpected ways. This is particularly true when the two chemicals...Full Text Available

2007-06-15

71

Identification of environmental chemicals with estrogenic activity using a combination of in vitro assays.  

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

1996-10-01

72

Chemical activation of MEK1 - a redox trigger for evaluating the effects of phosphorylation.  

Science.gov (United States)

An approach to generate mimics of phosphorylated serine proteins chemically through site-specific sulfonation of cysteine is presented. This chemical modification is reversible in the presence of reducing agent and therefore is analogous to the kinase/phosphatase system used in nature. PMID:21717004

2011-06-30

73

Absence of morphologic correlation between chemical toxicity and chemical carcinogenesis.  

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

1993-12-01

74

Molecular Genetics and Carcinogenesis Section  

Science.gov (United States)

The Molecular Genetics and Carcinogenesis Section conducts studies using human epithelial cells to assess: activation of proto-oncogenes by chemical and physical carcinogens; inactivation and dysregulation of tumor suppressor genes by chemical and physical

75

Hard Corrosion and Radiation-Resistant Coatings  

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

76

Environmental chemical-induced macrophage dysfunction.  

UK PubMed Central (United Kingdom)

Immunomodulation by environmental chemical contaminants and the role immune parameters play in toxicity and risk assessment studies is of increasing concern. Although considerable evidence has indicated...Full Text Available

1981-06-01

77

Chemical Carcinogenesis Testing and Related Issues ...  

Science.gov (United States)

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

1985-05-01

78

Atmospheric chemistry in volcanic plumes  

UK PubMed Central (United Kingdom)

Recent field observations have shown that the atmospheric plumes of quiescently degassing volcanoes are chemically very active, pointing to the role of chemical cycles involving halogen species and...Full Text Available

2010-04-13

79

Approaches to the evaluation of chemical-induced immunotoxicity.  

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

1995-12-01

80

Application of Key Events Analysis to Chemical Carcinogens and Noncarcinogens  

UK PubMed Central (United Kingdom)

The existence of thresholds for toxicants is a matter of debate in chemical risk assessment and regulation. Current risk assessment methods are based on the assumption that, in the absence of sufficient...Full Text Available

2009-09-01

86

Obtainment of lanthanum oxide by fractionated precipitation method  

International Nuclear Information System (INIS)

... ammonium compounds benzilic acid chemical preparation lanthanum oxides

1979-01-01

89

Interaction of silicides in the Pd - Mo - Si ternary system  

International Nuclear Information System (INIS)

... chemical reactions high temperature lattice parameters microhardness

90

Inorganic chemistry of astatine  

International Nuclear Information System (INIS)

On the basis of experimental and extrapolated values the physico-chemical properties of astatine are reviewed considering all oxidation states.

100

Breath Test for Chemicals (Volatile Organic Compounds)  

Science.gov (United States)

Breath Tests; Human Volunteers; Pilot Study

2011-09-16

102

An R&D Exploratory Investigation of Resin Binders for the ...  

Science.gov (United States)

... Descriptors : *POLYMERS, *BINDERS, *HOWITZERS, *COMBUSTIBLE CARTRIDGE CASES, CHEMICAL COMPOSITION, PROPELLING ...

1980-10-01

104

Contamination and restoration of groundwater aquifers  

Energy Technology Data Exchange (ETDEWEB)

Humans are exposed to chemicals in contaminated groundwaters that are used as sources of drinking water. Chemicals contaminate groundwater resources as a result of waste disposal methods for toxic chemicals, overuse of agricultural chemicals, and leakage of chemicals into the subsurface from buried tanks used to hold fluid chemicals and fuels. In the process, both the solid portions of the subsurface and the groundwaters that flow through these porous structures have become contaminated. Restoring these aquifers and minimizing human exposure to the parent chemicals and their degradation products will require the identification of suitable biomarkers of human exposure; better understandings of how exposure can be related to disease outcome; better understandings of mechanisms of transport of pollutants in the heterogeneous structures of the ...

1993-04-01

105

Investigation of the potential influence of production treatment chemicals on produced water toxicity  

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 ...

1993-11-14

106

Crystal and solution structures of an odorant-binding protein from the southern house mosquito complexed with an oviposition pheromone  

Energy Technology Data Exchange (ETDEWEB)

Culex mosquitoes introduce the pathogens responsible for filariasis, West Nile virus, St. Louis encephalitis, and other diseases into humans. Currently, traps baited with oviposition semiochemicals play an important role in detection efforts and could provide an environmentally friendly approach to controlling their populations. The odorant binding proteins (OBPs) in the female's antenna play a crucial, if yet imperfectly understood, role in sensing oviposition cues. Here, we report the X-ray crystallography and NMR 3D structures of OBP1 for Culex quinquefasciatus (CquiOBP1) bound to an oviposition pheromone (5R,6S)-6-acetoxy-5-hexadecanolide (MOP). In both studies, CquiOBP1 had the same overall six-helix structure seen in other insect OBPs, but a detailed analysis revealed an important previously undescribed feature. There are two models for OBP-mediated signal transduction: (i) direct release of the pheromone from an internal binding pocket in a ...

2010-11-15

107

Creation of bony microenvironment with CaP and cell-derived ECM to enhance human bone-marrow MSC behavior and delivery of BMP-2.  

Science.gov (United States)

Extracellular matrix (ECM) comprises a rich meshwork of proteins and proteoglycans, which not only contains biological cues for cell behavior, but is also a reservoir for binding growth factors and controlling their release. Here we aimed to create a suitable bony microenvironment with cell-derived ECM and biodegradable ?-tricalcium phosphate (?-TCP). More specifically, we investigated whether the ECM produced by bone marrow-derived mesenchymal stem cells (hBMSC) on a ?-TCP scaffold can bind bone morphogenetic protein-2 (BMP-2) and control its release in a sustained manner, and further examined the effect of ECM and the BMP-2 released from ECM on cell behaviors. The ECM was obtained through culturing the hBMSC on a ?-TCP porous scaffold and performing decellularization and sterilization. SEM, XPS, FTIR, and immunofluorescent staining results indicated the presence of ECM on the ?-TCP and the amount of ECM increased with the incubation time. BMP-2 was loaded onto ...

2011-05-31

108

A model of episodic memory: mental time travel along encoded trajectories using grid cells.  

Science.gov (United States)

The definition of episodic memory includes the concept of mental time travel: the ability to re-experience a previously experienced trajectory through continuous dimensions of space and time, and to recall specific events or stimuli along this trajectory. Lesions of the hippocampus and entorhinal cortex impair human episodic memory function and impair rat performance in tasks that could be solved by retrieval of trajectories. Recent physiological data suggests a novel model for encoding and retrieval of trajectories, and for associating specific stimuli with specific positions along the trajectory. During encoding in the model, external input drives the activity of head direction cells. Entorhinal grid cells integrate the head direction input to update an internal representation of location, and drive hippocampal place cells. Trajectories are encoded by Hebbian modification of excitatory synaptic connections between hippocampal place cells and head direction cells driven by external ...

2009-07-15

109

The chemical link Brazil/Portugal. Abstracts of the 23. annual meeting of the Brazilian Chemical Society. v. 2; A ligacao quimica Brasil/Portugal. Resumos da 23. reuniao anual da Sociedade Brasileira de Quimica. v. 2  

Energy Technology Data Exchange (ETDEWEB)

Several works about annual meeting of the Brazilian Chemical Society are present.The search for medicinal chemistry, natural products, biological chemistry, and organic chemistry are shown. Conventional methods and some techniques are discussed and developments of new methods of determining are studied. The use of new chemical compounds, materials, structures and chemical analysis are shown.

2000-07-01

110

Technological press on the environment: comparison of the radiation and conventional processing  

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).

1994-09-11

111

The application of computer modeling to health effect research  

Energy Technology Data Exchange (ETDEWEB)

In the United States, estimates show that more than 30,000 hazardous waste disposal sites exist, not including military installations, U.S. Department of Energy nuclear facilities, and hundreds and thousands of underground fuel storage tanks; these sites undoubtedly have their own respective hazardous waste chemical problems. When so many sites contain hazardous chemicals, how does one study the health effects of the chemicals at these sites? There could be many different answers, but none would be perfect. For an area as complex and difficult as the study of chemical mixtures associated with hazardous waste disposal sites, there are no perfect approaches and protocols. Human exposure to chemicals, be it environmental or occupational, is rarely, if ever, limited to a single chemical. Therefore, it is essential that we consider multiple ...

1996-12-31

112

Sources of toxicity and exposure information for identifying chemicals of high concern to children  

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 ...

2010-11-01

113

Supplier notification requirements under section 313 of the Emergency Planning and Community Right-to-Know Act (1991)  

International Nuclear Information System (INIS)

When Congress passed the Emergency Planning and Community Right-to-Know Act of 1986 (EPCRA), it created a number of new reporting requirements for companies that handle toxic chemicals and products containing toxic chemicals. Section 313 of EPCRA requires that certain manufacturers report annual releases to the environment of listed toxic chemicals and chemical categories. Because these manufacturers must know the toxic chemical composition of the products they use to be able to calculate releases accurately, EPA requires some suppliers of mixtures or trade name products containing one or more of the listed section 313 toxic chemicals to notify their customers. The pamphlet explains which suppliers must notify their customers, who must be notified, what form the notice must take, and when it must be sent.

114

Cumulative effects of in utero administration of mixtures of reproductive toxicants that disrupt common target tissues via diverse mechanisms of toxicity  

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...

2010-01-01

115

Biocide and corrosion inhibition use in the oil and gas industry: Effectiveness and potential environmental impacts  

International Nuclear Information System (INIS)

Treatment chemicals are used in all facets of the natural gas industry (NGI) from well development through transmission and storage of natural gas. The multitude of chemicals used, combined with the dozens of chemical manufacturers and/or suppliers has lead to the availability of hundreds of possible chemical products. Because of the widespread use of chemical products and their numerous sources, the NGI needs access to consistent data regarding their effectiveness and potential environmental impacts. The objective of this work was to evaluate the effectiveness and potential environmental impacts of, chemical products used in the NGI. This assessment was initially focused on biocides and corrosion inhibitors and their use in the gas production, storage and transmission facilities, The overall approach was obtain the necessary data on ...

1995-03-27

116

Theory of chemical reaction dynamics. Volume 3  

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.

1985-01-01

117

The Chemical Reactions of Sulfur in the Citrate Process for Flue Gas Desulfurization.  

Science.gov (United States)

The Bureau of Mines performed chemical research to elaborate details of sulfur chemistry pertaining to the citrate flue gas desulfurization process in which sulfur dioxide (SO2), absorbed (as bisulfite ion) in a buffered sodium citrate solution, is reduce...

1981-01-01

118

Quarterly progress report for the Chemical and Energy Research Section of the Chemical Technology Division: January--March 1997  

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 ...

1998-01-01

119

Pulmonary metabolism of foreign compounds: its role in metabolic activation.  

UK PubMed Central (United Kingdom)

The lung has the potential of metabolizing many foreign chemicals to a vast array of metabolites with different pharmacological and toxicological properties. Because many chemicals require metabolic...Full Text Available

1990-04-01

120

Predicting the carcinogenicity of chemicals in humans from rodent bioassay data.  

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

1991-08-01

121

Pore region of TRPV3 ion channel is specifically required for heat-activation  

UK PubMed Central (United Kingdom)

Ion-channels can be activated (gated) by a variety of stimuli including chemicals, voltage, mechanical force or temperature. Whereas molecular mechanisms of ion-channel gating by chemicals and...Full Text Available

2008-09-01

122

Physical Morphology and Quantitative Characterization of Chemical Changes of Weathered PVC/Pine Composites.  

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...

2009-01-01

123

Phase transitions in the soliton star model  

Energy Technology Data Exchange (ETDEWEB)

The aim of this paper is to obtain the effective potential of the non-topological soliton model at finite temperature with the assumption that the chemical potential {mu} of the system is different from zero and to analyse how the effective potential is influenced by changes in the chemical potential and temperature. (author)

1998-01-01

124

On the water-chemical regime in steam generators at NPP  

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.

2006-01-01

125

On the General Mechanism of Selective Induction of Cytochrome P450 Enzymes by Chemicals: Some Theoretical Considerations  

UK PubMed Central (United Kingdom)

Importance of the fieldThe cytochrome P450 (CYP) isoforms that are selectively induced following exposure to structurally-diverse chemicals often are the ones capable...Full Text Available

2010-04-01

126

Introduction and summary of the 13th meeting of the Scientific Group on Methodologies for the Safety Evaluation of Chemicals (SGOMSEC): alternative testing methodologies.  

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

1998-04-01

127

Hypothesis for induction and propagation of chemical sensitivity based on biopsy studies.  

UK PubMed Central (United Kingdom)

The reactive airways dysfunction syndrome (RADS), the reactive upper airways dysfunction syndrome (RUDS), the sick building syndrome (SBS), and the multiple chemical sensitivity syndrome (MCS) are overlapping...Full Text Available

1997-03-01

128

Force-dependent chemical kinetics of disulfide bond reduction observed with single-molecule techniques  

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

2006-05-09

129

Fluorine-19 NMR Chemical Shift Probes Molecular Binding to Lipid Membranes  

UK PubMed Central (United Kingdom)

The binding of amphiphilic molecules to lipid bilayers is followed by 19F NMR using chemical shift and line shape differences between the solution and membrane-tethered states of...Full Text Available

2008-05-22

130

Demonstration and Evaluation of Magnetic Descalers.  

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...

2001-01-01

131

Decontamination of nuclear facilities  

International Nuclear Information System (INIS)

Thirty-seven papers were presented at this conference in five sessions. Topics covered include regulation, control and consequences of decontamination; decontamination of components and facilities; chemical and non-chemical methods of decontamination; and TMI decontamination experience.

1982-09-19

132

Chemical structure and inhalation toxicity of lipopolysaccharides from bacteria on cotton.  

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

1980-09-01

133

Chemical effects on K x-ray intensity ratios in chromium compounds  

International Nuclear Information System (INIS)

K_#beta#/ K_#alpha# x-ray intensity ratio of chromium were measured in different chromium compounds. The results show the variation of the intensity ratio as a function of the chemical environment around the metal ion. (author)

2003-02-10

134

Chemical carcinogenesis: too many rodent carcinogens.  

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

1990-10-01

135

Calculations of physical and chemical reactions produced in irradiated water containing DNA  

Energy Technology Data Exchange (ETDEWEB)

Initial results obtained with a Monte Carlo computer program designed to link initial physical events in irradiated liquid water with subsequent chemical and biological events are presented. 10 refs., 4 figs., 3 tabs.

1985-01-01

136

CHEMICAL SPECIATION OF FLUE GAS DESULFURIZATION SLUDGE CONSTITUENTS  

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...

137

Boundary conditions for the paleoenvironment: chemical and physical processes in the pre-solar nebula  

Energy Technology Data Exchange (ETDEWEB)

Two additional hyperfine components of the interstellar radical C3H were detected. In addition, methanol was discovered in interstellar clouds. The abundance of HCCN and various chemical isomers in molecular clouds was investigated.

1985-02-01

138

BIOASSAY AND CHEMICAL ANALYSIS FOR HAZARDOUS MATERIALS IN RESIDUAL OILS. VOLUME 2. APPENDICES  

Science.gov (United States)

The report gives results of an examination, including mutagenic screening, of the chemical composition of residual fuel oils and their column chromatography pre-fractions. A degree of correlation between composition and mutagenicity has been achieved. Radionuclide data has been o...

139

Application of tumor, bacterial and parasite susceptibility assays to study immune alterations induced by environmental chemicals  

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

1982-02-01

140

Alteration of the chemical environment disrupts communication in a freshwater fish  

UK PubMed Central (United Kingdom)

It is well established that changes to the chemical environment can impair development, physiology and reproductive biology; by contrast, impacts on communication have not been widely reported. This...Full Text Available

2006-05-22

141

Acidizing subterranean well formations containing deposits of metal compounds  

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.

1979-04-24

142

1,3-Butadiene: linking metabolism, dosimetry, and mutation induction.  

UK PubMed Central (United Kingdom)

There is increasing concern for the potential adverse health effects of human exposures to chemical mixtures. To better understand the complex interactions of chemicals within a mixture, it is essential...Full Text Available

1994-11-01

143

Use of organic water treatment chemicals  

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.).

144

The preparation of carrier-free "2"0"3Pb for medical use  

International Nuclear Information System (INIS)

... bismuth 203 chemical reactions cyclotrons decay helium 3 beams impurities

146

The Modification of Polymer Surfaces and the Fabrication of ...  

Science.gov (United States)

... spatially defined fashion. Many surface modification techniques require a sequential chemical treatment of the surface.6 ...

1993-06-10

149
150

Plasma Enhanced Chemical Vapor Deposition (PECVD) Application And Atmospheric Pressure Plasma Characteristics  

International Nuclear Information System (INIS)

Atmospheric pressure plasma enhanced chemical vapour deposition system is built. The electrical and optical characteristics of the APPECVD system is given. The system is used to deposit conductive polymers and nano composites onto glass and metal surfaces. The morphological, optical, chemical and electrical characteristics of deposited surfaces are investigated using SEM, AFM four probe deposition purposes. The photovoltaic applications of plasma deposited polymers and nonconsumption are compared with deposited with electrochemical methods show different results. The electrical, chemical and morphological structures of the samples will be given.

2008-08-25

152

Nanostructured Materials from Impulse Plasma in Liquid  

International Science & Technology Center (ISTC)

Nanostructured Materials from Impulse Plasma in Liquid: Studying of Physical-Chemical Properties, Optimization of Conditions of Obtaining

153

Molecular models in the quantum-chemical investigation of the structure of defect centers on oxide catalysts  

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.

1987-05-01

154

Magnetic properties of oxovanadium(IV) complexes with bidentate on donor Schiff bases  

International Nuclear Information System (INIS)

(Feb 1977). Japan Syamal, A. Bombay Univ. (India). Univ. Dept. of Chemical

1977-01-01

155

MINEQL-PC. Chemical Equilibrium Composition of Aqueous Systems  

Energy Technology Data Exchange (ETDEWEB)

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

1986-11-21

156

Low-Cost Crystal Silicon  

International Science & Technology Center (ISTC)

The Development of Basic Plasma-Chemical Technology for Manufacture of Low Cost Crystal Silicon for Solar Power Plants.

158

Emergency Planning and Community Right-to-Know Act: Section 313 release reporting requirements (August 1991)  

International Nuclear Information System (INIS)

The brochure contains information about the Emergency Planning and Community Right-to-Know Act. This law establishes a structure at the state and local levels to assist communities in planning for chemical emergencies and requires facilities to provide information on various chemicals present in the community. The Act requires that this information be made available to the public. One of the requirements concerns the reporting of annual releases of toxic chemicals to the air, water, and land. These provisions are outlined in Section 313 which mandates annual release reporting for over 300 chemicals.

159

Effects of variable hardness, ph, alkalinity, suspended clay, and humics on the chemical speciation and aquatic toxicity of copper  

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.

1986-03-01

161

Chemical effects of L X-ray intensity ratios in niobium and molybdenum compounds  

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.).

1990-12-20

162

Chemical effects of L X-ray intensity ratios in niobium and molybdenum compounds  

International Nuclear Information System (INIS)

Chemical effects of L X-ray intensity ratios in niobium and molybdenum compounds were studied by electron and proton bombardments. L_#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_#gamma#_1/L_#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.).

1990-12-01

163

Biomass as feedstock for chemicals and energy on the threshold of the 21st. century  

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.

164

Absorption-Electrochemical Surface Decontamination  

International Science & Technology Center (ISTC)

Development of a Comprehensive Decontamination Database and an Absorption-Electrochemical Metal Surface Decontamination Technique Combining Chemical and Electrochemical Process

165

A comparative study of the fatty acid composition of prochloron lipids  

Science.gov (United States)

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

1983-01-01

166

Thermodynamics of reactions of chemically stable ceramics formation  

Energy Technology Data Exchange (ETDEWEB)

Theoretical thermodynamical calculations for the ZrO/sub 2/- Al/sub 2/O/sub 3/-SiO/sub 2/ system are given to expose the regions of the most chemically stable products of crystallization. It is established that ceramics on the base of mullite with zircon addition and containing the minimum quantity of glass phase should be preferably used in chemical media containing HCl.

1981-06-01

167

Theory of chemical reaction dynamics. Volume 1  

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.

1985-01-01

168

Sustainable phosphorous fertilisation of potatoes (Potato CHIPS)  

Environmental Research Database

DescriptionThis project has two independent aims: (1) to investigate the use of struvite as an alternative to chemical P fertilisers and (2) to develop an oligonucleotide microarray to monitor the P status of the potato crop. The UK horticultural and agricultural industries rely on large inputs of phosphate (P) fertilisers to maintain crop yields and quality. However, the use of non-renewable, chemical P fertilisers is unsustainable, and the alternatives to chemical P-fertilisers must be identified as an [continued...

2008-01-31

169

Request for interim approval to operate Trench 94 of the 218-E-12B Burial Ground as a chemical waste landfill for disposal of polychlorinated biphenyl waste in submarine reactor compartments. Revision 2.  

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 ...

1994-01-01

170

Microwaves action applied to chemical reactions and processes; L`azione delle microonde nelle reazioni e nei processi chimici  

Energy Technology Data Exchange (ETDEWEB)

Microwaves improve the rate of many chemical reactions either interacting with the solvent, when the reaction is carried out in solution, or with the surface of a solid substrate where a suitable reagent is dispersed (dry chemistry). A few examples of chemical reactions positively affected by microwaves are described: particularly interesting are those concerning polymers and radio-pharmaceuticals.

1997-03-01

171

Investigation of morphology and chemical composition of self-organized semiconductor quantum dots and wires by X-ray scattering  

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)

2001-09-23

172

Evaluation of indoor and outdoor climate on sites polluted with volatile organic chemicals  

International Nuclear Information System (INIS)

Papers presented at a meeting on indoor and outdoor climates on sites polluted with volatile organic chemicals. The papers deal with the subject of evaporation of organic chemicals on the polluted sites in relation to the influence on indoor and outdoor climates. Themes dealt with are diffusion through soils and transport of pollutants from the soil into buildings. (AB).

1993-11-04

173

Environmentally-Induced Malignancies: An In Vivo Model to Evaluate the Health Impact of Chemicals in Mixed Waste  

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.

2001-05-04

174

Detection device for high explosives  

Energy Technology Data Exchange (ETDEWEB)

A portable fiber optic detector that senses the presence of specific target chemicals by electrostatically attracting the target chemical to an aromatic compound coating on an optical fiber. Attaching the target chemical to the coated fiber reduces the fluorescence so that a photon sensing detector records the reduced light level and activates an appropriate alarm or indicator.

1992-01-01

175

Chemicals from coal: New processes  

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.

1987-01-01

176

Chemical sensitivity of the Ksub(. beta. )/Ksub(. cap alpha. ) x-ray intensity ratio for 3d elements  

Energy Technology Data Exchange (ETDEWEB)

Chemical influences on the relative Ksub(..beta..)/Ksub(..cap 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 polarizational effects are of importance.

1982-12-28

177

Chemical sensitivity of the Ksub(#nu#)/Ksub(#alpha#) x-ray intensity ratio for 3d elements  

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).

1982-12-01

178

Chemical assessments for international programmes III  

Environmental Research Database

DescriptionThis project continues DEFRA's commitment to the International Programme on Chemical Safety, a joint WHO/ILO/UNEP programme. DEFRA's contribution involves preparing Environmental Health Criteira Documents (EHCs), Concise International Chemical Assessments Documents (CICADS) and input to the OECD test Guidelines Programme and gneral risk assessment guidance. Peer reviews of documents prepared through other research in the IPCS network have also been carried out,as well as attending and hosting ta [continued...

2005-01-21

179

Catalytic chemistry  

Energy Technology Data Exchange (ETDEWEB)

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.

1991-01-01

180

Tissue structure, nuclear organization and gene expression in normal and malignant breast  

Energy Technology Data Exchange (ETDEWEB)

Because every cell within the body has the same genetic information, a significant problem in biology is to understand how cells within a tissue express genes selectively. A sophisticated network of physical and biochemical signals converge in a highly orchestrated manner to bring about the exquisite regulation that governs gene expression in diverse tissues. Thus, the ultimate decision of a cell to proliferate, express tissue-specific genes, or apoptose must be a coordinated response to its adhesive, growth factor, and hormonal milieu. The unifying hypothesis examined in this overview is that the unit of function in higher organisms is neither the genome nor the cell alone but the complex, three-dimensional tissue. This is because there are bidirectional connections between the components of the cellular microenvironment (growth factors, hormones, and extracellular matrix) and the nucl2048 These connections are made via membrane-bound receptors and transmitted to the nucleus, where ...

2000-01-27

181

Radiosensitization of human lung fibroblasts by chemicals that decrease ATP levels  

International Nuclear Information System (INIS)

Radiosensitization by lactate, pyruvate, nalidixic acid and novobiocin was studied in exponentially growing SH-18L human lung fibroblasts. All the chemicals had a slight radiosensitizing effect at a low concentration and a definite effect at a higher one. Decreases in the D_0 and/or Dq values were present in each dose survival curve. Fibroblasts incubated with the low concentration of each chemical for 24 hrs after X irradiation showed no reduction in intracellular ATP content, whereas, the higher concentration produced a significant decrease. These observations suggest that the decrease in the ATP content may be involved in the radiosensitization of human fibroblasts at high concentrations of these chemicals. In contrast, radiosensitization at a low concentration is not explained by a relationship to ATP content. Different mechanisms may be involved in radiosensitization at low and high concentrations of these ...

182

Natural plant chemicals: source of industrial and medicinal materials  

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 ...

1985-01-01

183

Evaluation of the long-term mechanical behavior in the near-fields considering chemical transitions of barrier materials  

International Nuclear Information System (INIS)

An analysis system for the long-term mechanical behavior of barrier materials (MACBECE: Mechanical Analysis system considering Chemical transitions of BEntonite-based and CEment-based materials) was developed in order to improve the reliability of the evaluation of the hydraulic field which is one of the important environmental conditions in the safety assessment of the TRU waste disposal. MACBECE is the system that calculates the deformation of barrier materials using their chemical property changes as inputs, and subsequently calculates their hydraulic conductivity taking both their chemical property changes and deformation into consideration. By using MACBECE, the long-term deformation and the transition of hydraulic field for the round-type disposal cavities were evaluated, assuming some sets of chemical evolution data as input. Based on the analysis result, it is considered that the influence of ...

2007-04-22

184

Structure activity relationships to assess new chemicals under TSCA  

International Nuclear Information System (INIS)

Under Section 5 of the Toxic Substances Control Act (TSCA), manufacturers must notify the US Environmental Protection Agency (EPA) 90 days before manufacturing, processing, or importing a new chemical substance. This is referred to as a premanufacture notice (PMN). The PMN must contain certain information including chemical identity, production volume, proposed uses, estimates of exposure and release, and any health or environmental test data that are available to the submitter. Because there is no explicit statutory authority that requires testing of new chemicals prior to their entry into the market, most PMNs are submitted with little or no data. As a result, EPA has developed special techniques for hazard assessment of PMN chemicals. These include (1) evaluation of available data on the chemical itself, (2) evaluation of data on analogues of the PMN, or evaluation of data on ...

1990-06-27

185

Density functional calculations of 15N chemical shifts in solvated dipeptides  

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 ...

2008-06-01

186

Chemical source identifications for natural resource injury/damage assessments and site assessments  

International Nuclear Information System (INIS)

Current regulations guiding technical aspects of natural resource damage assessments combine source, exposure pathway, resource injury, and monetary damage components. In order to associate any observed injury to the uncontrolled release of chemicals (e.g. oil spills, contaminated sediments, in-place toxics, etc.), it is important to link the chemical ''release'' to the injured resource. In complex environmental settings where multiple sources of similar chemicals are combined, multicomponent chemical methods must be used to link the release to the environmental distribution of chemicals. Three examples of the utility of multicomponent organic chemical analyses linked to comprehensive and representative sampling strategies will be discussed--the Shell Martinez Refinery oil spill, the Exxon Valdez oil spill, and a contaminated sediment assessment. These ...

1993-11-14

187

Simultaneous quantitative measurement of biodegradability and toxicity of environmental chemicals  

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 ...

1994-04-01

188

Conversion of a plasma enhanced chemical vapor deposited silicon-carbon-nitride thin film at ultra-low temperature by oxygen plasma  

Energy Technology Data Exchange (ETDEWEB)

In this work we present an ultra-low temperature method for the oxidation of an amorphous silicon-carbide-nitride (SiCN) material. The SiCN is deposited on silicon substrates by plasma enhanced chemical vapor deposition using CH{sub 4}, SiH{sub 4}, and N{sub 2} chemistry. The physical and chemical properties are characterized for the as-deposited SiCN and post-oxidized films are discussed. The SiCN film is exposed to oxygen plasma, where it undergoes a chemical transformation into a binary SiO{sub 2} material system. A 1.7 nm/min oxidation rate is typical for this process and compares favorably to oxidation methods utilizing much higher temperatures. The substrate temperature remains extremely low throughout the oxidation process, T{sub s} < 200 deg. C. Changes in film stress, optical constants, film thickness, surface roughness, and film density are measured. Chemical analysis by X-ray ...

2008-01-30

189

Radiation preservation of foods of plant origin. Part IV. Subtropical fruits: citrus, grapes, and avocados  

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.

1986-01-01

190

Proceedings of the 8. CANMET/ACI international conference on superplasticizers and other chemical admixtures in concrete : supplementary papers[ACI SP-239  

Energy Technology Data Exchange (ETDEWEB)

This book provided a set of supplementary papers provided to delegates at the eighth international CANMET/ACI conference on superplasticizers and chemical admixtures in concrete. Recent research on chemical admixtures and superplasticizers was presented along with new approaches to the practical application of concrete admixtures. The presentations highlighted technological advances in the development of superplasticizers and new approaches to the manufacture and implementation of aggregates. Issues regarding the application of plasticizers with various aggregates were addressed, and interactions between cements and superplasticizers were evaluated. Four of the supplementary papers have been catalogued separately for inclusion in this database. refs., tabs., figs.

2006-07-01

191

Influence of anaerobic microbial activity on biosorption of 2,4-dichlorophenol  

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.

1995-12-31

192

Development of a chemically assisted micro-beam etching system for three-dimensional microanalysis  

Energy Technology Data Exchange (ETDEWEB)

A chemically assisted micro-beam etching system for 3D microanalysis was designed. Using chemically assisted ion beam etching (CAIBE) method with FIB shave-off scanning, about several hundred micrometers clean cross-section will be acquired in a few hours. We use focused ion beam (FIB) and electron beam (EB) as micro-beams, halogen or halide mainly as reactive gases. The apparatus was manufactured based on this concept. We found that the FIB, Q-MS and SED worked as expected. The instrumentation has been completed.

2003-01-15

193

Chemical compatibility study of Cooley L18KU, Herculite, and Elephant Mat with Hanford tank waste  

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.

1998-06-23

194

Why the United States Must Deploy a National Missile ...  

Science.gov (United States)

... transItion to more capable space-based interceptors as ... ten wtth bmlogtcal, and thirty with chemical weapons. ... are becoming the weapon of choice ...

2011-05-14

195

WKK-potential in the chemical industry; WKK-potentieel in de chemische industrie  

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.

2009-11-15

196

Today in History: December 17  

Science.gov (United States)

as manufacturing plants and laboratories, including the Chemical Laboratory at the House of David in Benton Harbor, Michigan. Built in America: Historic Building Buildings Survey/...

2010-12-17

197

Thermodynamic, Transport and Chemical Properties of " ...  

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. ...

2006-06-01

198

Theory of the crystal-liquid phase transition  

Science.gov (United States)

The SCF approximation is used in a statistical theory of melting based on equality of the chemical potentials. The results for the melting points of the inert gases are close to the observed values.

1967-02-01

199

Theoretical Basis of Protocols for Seed Storage  

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

1990-11-01

201

The Structure of Plant Cell Walls  

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

1973-01-01

202

Synthesis, Characterization and Chondroprotective Properties of a Hyaluronan Thioethyl Ether Derivative  

UK PubMed Central (United Kingdom)

Hyaluronan (HA), a non-sulfated glycosaminoglycan, is widely used in the clinic for viscosurgery, viscosupplementation, and treatment of osteoarthritis. Four decades of chemical modification...Full Text Available

2008-04-01

206

Research Activities in the Spokane, Washington, Field Office...  

Science.gov (United States)

other chemical applications include use in water softeners, detergents, and food additives. The development of phosphate resources as a leasable commodity provides income to...

2011-08-20

207

Report on NCI symposium: comparison of mechanisms of carcinogenesis by radiation and chemical agents. II. Cellular and animal models  

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 ...

1984-05-20

209

REVIEW OF EXPLOSIVE (CHEMICAL) FORMING  

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. ...

1965-04-01

210

Possible preparation of wood-plastic composites based on unsaturated polyester resins and styrene by radiation and chemical methods in combination  

Energy Technology Data Exchange (ETDEWEB)

Using the radiation chemical method it is possible to prepare wood-plastic composites using doses of 1 to 2.5 kGy. The impregnation mixture in the wood gelatinates and subsequent curing using chemical initiators takes place without outflow of the mixture from the wood and without formation of incrustations. The basic components of the impregnation mixtures used were unsaturated polyester resins; styrene or methyl methacrylate was used as the thinner. The proven initiator of polymerization was 2,2'-azobisisobutyronitrile. The technology is described of wood impregnation and radiation or chemical curing. The effects were monitored of viscosity, temperature, radiation dose and the concentrations of the individual components of the impregnation mixtures and initiators of polymerization on the process of the preparation of wood-plastic composites.

1983-06-01

211

Polycarbonate Bottle Use and Urinary Bisphenol A Concentrations  

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

2009-09-01

212

Poisoning young minds.  

UK PubMed Central (United Kingdom)

For some neurotoxic chemicals, neurobehavioral effects are now considered to be among the most sensitive end points yet detected, particularly if exposures occur during critical windows of vulnerability....Full Text Available

1999-06-01

213

OSHA Hazardous-Chemical Occupational Exposure Standard for laboratories: A new management regulation to ensure employee health. Final report  

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.

1991-04-01

214

NSF-NIST Interaction in Chemistry, Materials Research, Molecular Biosciences, Bioengineering and Chemical Engineering  

Science.gov (United States)

NSF-NIST Interaction in Chemistry, Materials Research, Molecular Biosciences, Bioengineering, and ... Laboratory (CSTL). Materials research is centralized in the Materials Science and Engineering ...

215

NASA TECH BRIEF - NASA Technical Report Server (NTRS)  

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. ...

216

NASA - NASA Selects Pennsylvania Firm to Build Liquid Nitrogen Plant  

Science.gov (United States)

Sep 21, 2006 ... NASA has selected Air Products and Chemicals, Inc., Allentown, Pa., to design, furnish and install a plant to produce liquid nitrogen for ...

217

Microstructure and properties of ultrafine WC-10Co composites with chemically doped VC  

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 ...

2011-01-01

218

Mechanism of action of lenalidomide in hematological malignancies  

UK PubMed Central (United Kingdom)

Immunomodulatory drugs lenalidomide and pomalidomide are synthetic compounds derived by modifying the chemical structure of thalidomide to improve its potency and reduce its side effects. Lenalidomide...Full Text Available

219

Kinetic energy dependence of the reactions of N"+ ions with NO, CO, CO_2, N_2O and SO_2  

International Nuclear Information System (INIS)

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

1977-07-01

220

Fourier transform IR studies on the interaction of selected chemicals with isolated cuticles  

International Nuclear Information System (INIS)

It is known that the plant cuticle represents the first barrier that must be overcome by any chemical reaching the plant surface from the atmosphere before entering the plant. Because of the importance of the cuticle as a barrier to penetration of a wide variety of compounds, its morphology, chemistry, and permeability have been extensively studied. However, only limited information is available on the nature of functional chemical groups present and their interaction and role during the penetration process. The usefulness of in situ Fourier transform infrared spectroscopy studies in identifying functional groups present in isolated cuticles is described and their relationships to the structure of the cuticular membrane are discussed. Applications of infrared spectroscopy on the presence and role of phenolics in the cuticle structure and during the cuticle development, nitrogen oxide binding to isolated cuticles, and the interactions between ...

222

Factors Influencing the Effectiveness of Swimming Pool Bactericides  

UK PubMed Central (United Kingdom)

Techniques for culturing, harvesting, and testing bacteria to evaluate bactericidal chemicals for swimming pools are described. Concentrations of 25, 50, and 100 mg of the chlorine stabilizer cyanuric...Full Text Available

1967-05-01

223

Environmental and toxicological aspects of insect growth regulators.  

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

1976-04-01

224

Emergencies > Poisoning > Lead Poisoning | Browse EPA Topics...  

Science.gov (United States)

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

2011-01-20

225

Emergencies > Oil Spills > Facility Response Plan | Browse EPA...  

Science.gov (United States)

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

2011-01-20

226

Emergencies > Emergency Response > September 11 Response | Browse...  

Science.gov (United States)

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

2011-01-20

227

Emergencies > Emergency Response > Countermeasures | Browse EPA...  

Science.gov (United States)

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

2011-01-20

228

Emergencies > Disasters > Floods | Browse EPA Topics | US EPA  

Science.gov (United States)

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

2011-01-20

229

ELECTRICAL ACTIVITY IN THE CHEMORECEPTORS OF THE BLOWFLY  

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

1958-11-20

230

Development of Methods for Obtaining Position Image and Chemical Binding Information from Flow Experiments of Porous Media  

Energy Technology Data Exchange (ETDEWEB)

Existing oil reservoirs might be more fully exploited if the properties of the flow of oil and water in porous media were better known. In laboratory experiments it is important to collect as much information as possible to make a descriptive model of the system, including position imaging and chemical binding information. This thesis develops nuclear methods for obtaining position image and chemical binding information from flow experiments of porous media. A combined positron emission tomography and single photon emission computed tomography system to obtain position images, and a time-differential perturbed angular correlation system to obtain chemical binding information, have been built and thoroughly tested. 68 refs., 123 figs., 14 tabs.

1998-12-01

231

Detailed Chemical Kinetic Reaction Mechanisms for Incineration of Organophosphorus and Fluoro-Organophosphorus Compounds  

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 ...

2001-12-13

232
233

Content of hydrogen, helium, and heavy elements in Procyon  

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.

1985-05-01

234

Comparative genomics of insect juvenile hormone biosynthesis?  

UK PubMed Central (United Kingdom)

The biosynthesis of insect juvenile hormone (JH) and its neuroendocrine control are attractive targets for chemical control of insect pests and vectors of disease. To facilitate the molecular...Full Text Available

2006-04-01

235

Chemical versus solvent extraction treatment: Comparison and influence on polyester based bio-composite mechanical properties  

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...

2010-01-01

236

Chemical resistance, void content and tensile properties of oil palm/jute fibre reinforced polymer hybrid composites  

British Library Electronic Table of Contents (United Kingdom)

Tri layer hybrid composites of oil palm empty fruit bunches (EFB) and jute fibres was prepared by keeping oil palm EFB as skin material and jute as the core material and vice versa. The chemical resistance, void content and tensile properties of oil palm EFB/Jute composites was investigated with reference to the relative weight of oil palm EFB/Jute, i.e. 4:1, the fibre loading was optimized and different layering pattern were investigated. It is found from the chemical resistance test that all the composites are resistant to various chemicals. It was observed that marked reduction in void content of hybrid composites in different layering pattern. From the different layering pattern, the tensile properties were slightly higher for the composite having jute as skin and oil palm EFB as core ...

2011-01-01

237

Chemical composition of passive films on AISI 304 stainless steel  

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).

1994-12-01

239

Chemical and Biological Warfare: A Manageable Problem  

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 ...

2003-01-27

240

Chemical Defense and the Persistence of Pioneer Plant Seeds in the Soil of a Tropical Cloud Forest:  

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT We present evidence that differences in soil seedbank persistence among pioneer plants in the cloud forest of Monteverde, Costa Rica, are influenced by differences in seed chemical defense. We used extracted seed chemicals from Bocconia frutescens (Papaveraceae), Guettarda poasana (Rubiaceae), Phytolacca rivinoides (Phytolaccaceae), Urera elata (Urticaceae), Cecropia polyphlebia (Cecropiaceae), and Witheringia meiantha (Solanaceae) to assess seed chemical defense in two ways: (1) a plant pathogen inhibition assay using Pythium irregulare; and (2) a brine shrimp toxicity assay using Artemia salina. The combined performance of each species in the two assays positively correlated with seedbank persistence. In the pathogen assay, mycelium growth was reduced when Pythium was cultured o...

2007-01-01

241

Big bang nucleosynthesis  

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.

2000-01-01

243

Advances in feedstock recycling offer help with plastic waste  

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.

1993-10-04

244

Advanced synchronous luminescence system  

Energy Technology Data Exchange (ETDEWEB)

A method and apparatus for determining the condition of tissue or otherwise making chemical identifications includes exposing the sample to a light source, and using a synchronous luminescence system to produce a spectrum that can be analyzed for tissue condition.

1997-01-01

245

Adducted proteins for identification of endogenous electrophiles.  

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

1993-03-01

246

A Model for Chlorine Dioxide Delignification of Chemical Pulp  

British Library Electronic Table of Contents (United Kingdom)

A phenomenon based model for chlorine dioxide delignification of chemical pulp is introduced. The pulp suspension environment is modeled using the concept of two liquid phases, one inside and the other external to the fiber wall. Physico-chemical processes taking place during delignification are implemented with thermodynamic, mass transfer and reaction kinetic models. A broad library of chemical reactions is introduced. Inclusion of each reaction is justified. The model response is tested against experimental laboratory delignification results (o-delignified birch pulp). The experimental data consists of kappa number, hexenuronic acid, inorganic oxy-chlorine compound, and organochlorine (AOX, OX) measurements at several time points during five delignification experiments. The model predic...

2010-01-01

247

A High Throughput Combinatorial Library Technique for Identifying Formalin-Sensitive Epitopes  

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

2006-12-20

248

Contrasting Diffusion Patterns for PC and Mobile Videos: A User-Centric View of the Influencing Factors  

Science.gov (United States)

As both computer and mobile phone reach nearly ubiquity in the U.S. market, the slow uptake of mobile video, in contrast to the thriving usage of PC-based video, warrants a deeper understanding of user-oriented factors contributing to the two diffusion paths. Unlike the majority of existing diffusion research practices, the dissertation examines the differences between mobile and PC video diffusion patterns through the lenses of user-oriented influences in the user-technology relationship. Built upon the established adoption user group classification, the research is informed by the Uses and Gratification theory, the Social Technical theory, and the Technical Affordance perspective. These synergistic theoretical arguments share the recognition of the role of user in the dynamic, usually socially intertwined user-technology interactions. The key research questions that the dissertation sets out to answer include: Does the importance of quality of viewing experience in adoption ...

2009-12-01

249

Water chemistry and corrosion in water-steam circuits of nuclear power plants  

Energy Technology Data Exchange (ETDEWEB)

The water and steam circuits of steam generators in pressurized-water nuclear power plants are described together with the mechanism of denting, and the corrosion of spacer plates that leads to cracks in tubes by constriction. The different chemical specifications applicable to the water of the secondary circuit of the generators in normal operation and on first commissioning are listed. The results obtained and the measurements of chemical values taken in operation on the water in the secondary circuits of steam generators at Fessenheim and Bugey are presented.

1981-05-01

250

Water chemistry and corrosion in water-steam circuits of nuclear power plants  

International Nuclear Information System (INIS)

The water and steam circuits of steam generators in pressurized-water nuclear power plants are described together with the mechanism of denting, and the corrosion of spacer plates that leads to cracks in tubes by constriction. The different chemical specifications applicable to the water of the secondary circuit of the generators in normal operation and on first commissioning are listed. The results obtained and the measurements of chemical values taken in operation on the water in the secondary circuits of steam generators at Fessenheim and Bugey are presented.

251

Theoretical studies of Cerro Prieto brines chemical equilibria  

Energy Technology Data Exchange (ETDEWEB)

A chemical equilibrium model is used, implemented in a compact FORTRAN package called HITEQ, to investigate possible mineral deposition related to prereinjection treatment of Cerro Prieto brines for silica removal. Large saturation ratios of the treated brines with respect to several minerals are indicated by these computations. As a remedy, an inexpensive CO/sub 2/ removal scheme aimed at inhibiting carbonate mineral precipitation is proposed. This scheme is quantitatively discussed with the aid of HITEQ. It is concluded that the proposed treatment is both technically and economically feasible.

1980-02-01

252

The chemical properties of silica particle surface in relation to silica-cell interactions  

Energy Technology Data Exchange (ETDEWEB)

Although silicosis has been studied extensively, the mechanism is still not fully understood. Experiments do provide evidence that the actions of unique properties of silica surface on the cell membrane are the starting point of silicotic processes. This paper summarizes literature on chemical properties of silica surface, and the effect of particle size on silica toxicity. This paper also discusses the ways in which silica dusts are though to interact with the cell membrane, with emphasis on freshness, hydrogen bonding, and free-radical interactions.

1989-01-01

253

Request for interim approval to operate 218-E-12B Trench 94 as a chemical waste landfill for disposal of polychlorinated biphenyl wastes in submarine reactor compartments. Revision 1.  

Science.gov (United States)

This request is submitted to seek interim approval to operate a chemical waste landfill for the disposal of polychlorinated biphenyl (PCB) waste. Interim approval is requested for a period not to exceed 5 years. This request covers only the disposal of sm...

1992-01-01

254

Request for interim approval to operate 218-E-12B Trench 94 as a chemical waste landfill for disposal of polychlorinated biphenyl wastes in submarine reactor compartments.  

Science.gov (United States)

This request is submitted to seek interim approval to operate a chemical waste landfill for the disposal of polychlorinated biphenyl (PCB) wastes. This request covers only the disposal of small quantities of solid PCB wastes contained in decommissioned su...

1990-01-01

255

Report of National Cancer Institute symposium: comparison of mechanisms of carcinogenesis by radiation and chemical agents. I. Common molecular mechanisms  

Science.gov (United States)

Some aspects of molecular mechanisms common to radiation and chemical carcinogenesis are discussed, particularly the DNA damage done by these agents. Emphasis is placed on epidemiological considerations and on dose-response models used in risk assessment to extrapolate from experimental data obtained at high doses to the effects from long-term, low-level exposures. 3 references, 6 figures. (ACR)

1984-01-01

256

Renewable resources - prospects for the chemicals industry  

International Nuclear Information System (INIS)

Improved boundary conditions for the cultivation and utilization of renewable feedstocks in Europe as well as advances in the manufacture and use of intermediate products, special and fine chemicals, and new materials on this basis were the topics of a second symposium, organized this time by Hoechst AG, together with the federal ministry of food, agriculture and forestry, in Frankfurt-Hoechst on May 5th and 6th. With more than 300 attendants from the sectors politics, farming, industry, science and administration, the meeting again encountered great interest. (orig.).

257

Quantitative spectroscopy of close binary stars  

CERN Document Server

The method of spectral disentangling has now created the opportunity for studying the chemical composition in previously inaccessible components of binary and multiple stars. This in turn makes it possible to trace their chemical evolution, a vital aspect in understanding the evolution of stellar systems. We review different ways to reconstruct individual spectra from eclipsing and non-eclipsing systems, and then concentrate on some recent applications to detached binaries with high-mass and intermediate-mass stars, and Algol-type mass-transfer systems.

2011-01-01

258

Pulsed plasma processing of effluent pollutants and toxic chemicals  

International Nuclear Information System (INIS)

The author is exploring the efficiency of pulsed plasma processing in the removal of nitrogen dioxide, nitrogen oxide, and other pollutants. This process uses an electrical discharge to create chemical radicals from air molecules. These radicals can react with pollutants and form harmless compounds. Additives such as hydrocarbons are also used to improve the efficiency of the removal. The efficient removal of nitrogen dioxide has required the presence of dilute aqueous solution of ammonia.

1994-05-01

259

Progress report, December 1, 1979-November 30, 1980. [Chemical poisoning of heterogeneously catalyzed reactions on transition metal surfaces  

Energy Technology Data Exchange (ETDEWEB)

The mechanism of chemical poisoning of model heterogeneously catalyzed reactions on transition metal surfaces is studied. Clean Mo(001) surfaces were characterized; results suggest a first-layer contraction of 10% of the bulk interlayer spacing. Characterization of clean Co(0001) surfaces is underway. Decomposition of formic acid on Mo(001) surfaces is being studied. (DLC)

1980-01-01

260

Poster 20. Analysis of chemical environment conditions in boiling zones  

International Nuclear Information System (INIS)

Boiling phenomenon is responsible for impurities concentration in the liquid phase and then can involve chemically aggressive conditions. This paper presents the methodology developed by NOVATOME to know the water quality conditions in the boiling zone and under deposits, in order to improve corrosion tests and materials reliability and safety. Calculations show that concentration of chloride and sodium hydroxide for example can reach significant levels which may lead to corrosion risks. (author).

261

Physical mechanisms of biological molecular motors  

Energy Technology Data Exchange (ETDEWEB)

Biological motors generally fall into two categories: (1) those that convert chemical into mechanical energy via hydrolysis of a nucleoside triphosphate, usually adenosine triphosphate, regarded as life's chemical currency of energy and (2) membrane bound motors driven directly by an ion gradient and/or membrane potential. Here we argue that electrostatic interactions play a vital role for both types of motors and, therefore, the tools of physics can greatly contribute to understanding biological motors.

2009-03-01

262

PWR steam generator chemical cleaning process  

International Nuclear Information System (INIS)

Some of the origins of corrosion encountered in the secondary side of pressurized water reactor steam generators are:-sludge accumulation (a mixture of metal oxides, primarily magnetite and copper) on tube sheet and attack of tube support plates by aggressive impurities leading to denting. Although Electricite de France has not suffered from these problems, it has developed a chemical cleaning process to dissolve corrosion products at both locations. (author).

1986-10-13

263

Method and apparatus for detecting explosives  

Energy Technology Data Exchange (ETDEWEB)

A method and apparatus is provided for detecting explosives by thermal imaging. The explosive material is subjected to a high energy wave which can be either a sound wave or an electromagnetic wave which will initiate a chemical reaction in the explosive material which chemical reaction will produce heat. The heat is then sensed by a thermal imaging device which will provide a signal to a computing device which will alert a user of the apparatus to the possibility of an explosive device being present.

2011-05-10

264

Methanol -a perspective raw material for the chemical industry  

Energy Technology Data Exchange (ETDEWEB)

Several new development trends in the processing of methanol to various chemical products are discussed. The production of acetic acid by carbonylation of methanol will increase. In the future, methanol is expected to represent the raw material in the production of lower alkenes. The synthesis of lower alcohols, of synthetic gas (homologation), and of aromatic hydrocarbons from methanol are in the research stage.

1983-08-01

265

Measurement of the electrical resistivity of the lithium isotopes at low temperatures  

Energy Technology Data Exchange (ETDEWEB)

The electrical resistivity at low temperatures (T = 10 to 90 K) of the lithium isotopes /sup 6/Li and /sup 7/Li and of an isotopic mixture /sup 7 +6/Li has been studied. The specimens contained a small amount of chemical impurities. An appreciable difference was observed in the temperature dependence of the resistivity produced both by deformation of the phonon spectrum, related to the change in isotopic composition, and by the presence of chemical impurities making the nonequilibrium part of the electron distribution function more isotropic.

1982-03-01

266

MOS device chemical response reversal with temperature  

British Library Electronic Table of Contents (United Kingdom)

Biased above threshold (VT), pulsed photocurrent (u) measurements on windowed silicon Pd gate MOS capacitors are shifted (DV) negatively by H2/N2, whereas Au gates shift positively under NO2/air. Below VT, the shifts are reversed by adjustments of interface state population. Minor temperature increases may coax the device from inversion to depletion, inducing sign reversal of the chemical response.

2010-01-01

267

Green chemistry at work  

Energy Technology Data Exchange (ETDEWEB)

The 1.7 billion pounds of benzene produced each year in the US provide one measure of its utility. At the same time, there are a number of environmental reasons for avoiding the use of benzene in chemical manufacture. Perhaps most compelling: benzene is a potent carcinogen. Scrutiny of many of the chemicals derived from benzene reveals that each molecule contains at least one oxygen atom while benzene completely lacks oxygen atoms. Introduction of oxygen to make up for this lack can require processes that are environmentally problematic. One of the steps used to introduce oxygen atoms during manufacture of adipic acid, a component of Nylon 66, is responsible for 10% of the annual global increase in atmospheric nitrous oxide. This by-product is a causative agent of atmospheric ozone depletion and has been implicated in global warming. With support from EPA and the National Science Foundation, alternative manufacturing processes are being ...

1994-12-31

268

Fouling Study of Silicon Oxide Pores Exposed to Tap Water  

Energy Technology Data Exchange (ETDEWEB)

We report on the fouling of Focused Ion Beam (FIB)-fabricated silicon oxide nanopores after exposure to tap water for two weeks. Pore clogging was monitored by Scanning Electron Microscopy (SEM) on both bare silicon oxide and chemically functionalized nanopores. While fouling occurred on hydrophilic silicon oxide pore walls, the hydrophobic nature of alkane chains prevented clogging on the chemically functionalized pore walls. These results have implications for nanopore sensing platform design.

2007-07-12

269

Extended range chemical sensing apparatus  

Energy Technology Data Exchange (ETDEWEB)

An apparatus for sensing chemicals over extended range of concentrations. In particular, first and second sensors each having separate, but overlapping ranges for sensing concentrations of hydrogen are provided. Preferably, the first sensor is a MOS solid state device wherein the metal electrode or gate is a nickel alloy. The second sensor is a chemiresistor comprising a nickel alloy.

1994-01-01

270

Enhanced Degradation of an Endocrine-Disrupting Chemical, Butyl Benzyl Phthalate, by Fusarium oxysporum f. sp. pisi Cutinase  

UK PubMed Central (United Kingdom)

Compared to yeast esterase, fungal cutinase degraded butyl benzyl phthalate (BBP) far more efficiently; i.e., almost 60% of the BBP disappeared within 7.5 h. Also, the final chemical composition significantly...Full Text Available

2002-09-01

271

Effectiveness of information provision in reducing risks to the environment  

Environmental Research Database

DescriptionAs part of a wider effort to develop new approaches to evaluating and quantifying the benefits of chemicals regulation, this project will review the effectiveness of existing information provision tools (such as classification and labelling for hazardous properties) in terms of affecting user behaviour. As some EC legislation relating to regulation of chemicals has been in place for some time, an assumption is made that the information provided by it is leading to an improvement in the way chem [continued...

2005-01-30

272

Effect of calcination and physico-chemical properties of red mud  

Energy Technology Data Exchange (ETDEWEB)

Physico-chemical studies were carried out on a sample of red mud collected from NALCO, Orissa, after calcination up to 1,200 C at an interval of 100 C. The observed change in properties like surface area, particle size, bulk density and mineral phases etc., can be profitably used while finding an appropriate application of this polluting waste from alumina plants.

1996-10-01

273

Design of solar receivers for chemical energy storage and pyroheliometallurgy applications  

Energy Technology Data Exchange (ETDEWEB)

A preliminary study of two different kinds of solar receivers (a rotating cavity receiver and a volumetric receiver) suitable to operate in the 1 kW solar facility at the University of Rome is presented. Possible applications of solar energy in the aluminum extraction from leucite and chemical storage by the CuO/Cu[sub 2]O cycle are presented and discussed. (author).

1992-01-01

274

DEFINITIVE SOX CONTROL PROCESS EVALUATIONS: AQUEOUS CARBONATE AND WELLMAN-LORD (ACID, ALLIED CHEMICAL, AND RESOX) FGD (FLUE GAS DESULFURIZATION) TECHNOLOGIES  

Science.gov (United States)

The report gives results of economic evaluations of two processes: the Rockwell International aqueous carbonate process (ACP) and the Wellman-Lord process, the latter applied to a sulfuric acid plant, the Foster Wheeler Resox process, and the Allied Chemical coal reduction proces...

275

Comparison of the genetic effects of equimolar doses of ENU and MNU: While the chemicals differ dramatically in their mutagenicity in stem-cell spermatogonia, both elicit very high mutation rates in differentiating spermatogonia  

UK PubMed Central (United Kingdom)

Mutagenic, reproductive, and toxicity effects of two closely related chemicals, ethylnitrosourea (ENU) and methylnitrosourea (MNU), were compared at equimolar and near-equimolar doses in the...Full Text Available

2007-03-01

276

Combining xenoestrogens at levels below individual no-observed-effect concentrations dramatically enhances steroid hormone action.  

UK PubMed Central (United Kingdom)

The low potency of many man-made estrogenic chemicals, so-called xenoestrogens, has been used to suggest that risks arising from exposure to individual chemicals are negligible. Another argument used...Full Text Available

2002-09-01

277

Coir fibre toxicity: in vivo and in vitro studies.  

Science.gov (United States)

The biological activity of coir fibre, coir ash and their components were investigated in vitro by measuring the haemolytic activity and macrophage cytotoxicity. In vivo studies carried out by injecting guinea pigs intratracheally with coir fibres resulted in resolving granulomas. The observed haemolytic activity and macrophage cytotoxicity was more marked with coir ash compared with coir fibres. Chemical analysis of coir ash revealed the presence of toxic chemical constituents in appreciable amounts. PMID:6283694

1982-03-01

278

Chemical modification of humic acids by the introduction of indole-containing fragments  

British Library Electronic Table of Contents (United Kingdom)

A method for the chemical modification of the initial structure of humic acids by acylation with indole-3-acetic acid chloride was developed to increase the biological activity of preparations based on peat and lignite humic acids. The plant growth stimulating effect and the antibacterial activity of the synthesized humic preparations were studied.

2011-01-01

279

Chemical effects on L_#gamma#_1/L_#beta#_1 x-ray intensity ratio of molybdenum compounds  

International Nuclear Information System (INIS)

Chemical effects on the intensity ratio of LX-ray of molybdenum compounds irradiated by 11-keV electrons and by 3-MeV protons were studied using an x-ray crystal spectrometer. It was found that the intensity ratios of L_#gamma#_1/L_#beta#_1 markedly decrease with the increase of ionicity of molybdenum compounds, except for the case of metallic molybdenum. (author).

1987-06-01

280

Behavior and impact assessment of heavy metals in estuarine and coastal zones  

Energy Technology Data Exchange (ETDEWEB)

Contents include: introduction; river systems; physical processes; chemical processes; estuaries and coastal zone; introduction; physical processes; chemical processes; the role of sediments; introduction; the anoxic layer; major-element chemistry; minor-element chemistry; the oxic-anoxic interface; assessment; introduction; analysis of sediments; modelling.

1987-01-01

281

A method for isolating a water influx into a well  

Energy Technology Data Exchange (ETDEWEB)

The goal of the invention is to increase the effectiveness of the isolation process through increasing the waterproofing of the stratum. The cited goal is achieved by isolating water influx into a well through introduction of a chemical reagent into the stratum. To interact with the stratum, an alloy of titanium and iron is introduced into the stratum as the chemical reagent with subsequent pumping of hydrogen into the stratum at 100 to 200C.

1983-01-01

282

Hydrogen production from fossil fuels with carbon dioxide capture, using chemical-looping technologies  

Energy Technology Data Exchange (ETDEWEB)

Carbon capture and storage have been receiving increasing interest lately, mainly as an option to reduce CO{sub 2} emissions from the power sector. The concept could be adapted for production of H{sub 2} as well, which would provide a carbon free energy carrier that could be used for example as transportation fuel. In this doctoral thesis, the option to use chemical-looping technologies to produce H{sub 2} from fossil fuels with CO{sub 2} capture is explored. In chemical-looping combustion, direct contact between fuel and combustion air is avoided. Instead, a solid oxygen carrier performs the task of bringing oxygen from the air to the fuel. Thus, the resulting CO{sub 2} and H{sub 2}O are not diluted with N{sub 2}, and pure CO{sub 2} can easily be recovered by cooling and condensation. The heat of reaction is the same as for ordinary combustion. Chemical-looping reforming uses the same basic principles as ...

2008-04-15

283

Toxicological benchmarks for screening contaminants of potential concern for effects on freshwater biota  

International Nuclear Information System (INIS)

An important early step in the assessment of ecological risks at contaminated sites is the screening of chemicals detected on the site to identify those that constitute a potential risk. Part of this screening process is the comparison of measured ambient concentrations to concentrations that are believed to be nonhazardous, termed benchmarks. This article discusses 13 methods by which benchmarks may be derived for aquatic biota and presents benchmarks for 105 chemicals. It then compares them with respect to their sensitivity, availability, magnitude relative to background concentrations, and conceptual bases. This compilation is limited to chemicals that have been detected on the US Department of Energy's Oak Ridge Reservation (ORR) and to benchmarks derived from studies of toxic effects on freshwater organisms. The list of chemicals includes 45 metals and 56 industrial organic ...

284

Role of accelerator mass spectrometry in biological dosimetry  

International Nuclear Information System (INIS)

Understanding risks from exposures to carcinogens and other chemicals depends upon measurement of their dose to target tissues and their reactivity with critical macromolecules. The authors have used AMS detection of radio-isotopes to assess doses and reactivities at low, environmentally relevant doses. Several biomedical investigations show the effectiveness of quantification of biologically important events at extremely high sensitivity with AMS. Specifically, they have measured the addition of environmental carcinogens such as 2-amino-3,8-dimethylimidazo[4,5-f]-quinoaxaline (MelQx), a chemical found in cooked food, to DNA at concentrations relevant to human exposure. Other low level detection problems in biology, such as immunoassay assessment of small environmental chemicals, is being developed with attomole sensitivity. AMS also aids the assessment of genotoxic risks from chemicals by quantifying ...

1992-04-05

285

Occupational health priorities for health standards: the current NIOSH approach.  

Science.gov (United States)

Government agencies responsible for protecting the public from the adverse effects of toxic chemicals must set priorities for research, regulatory action, protocol testing, and monitoring due to the vast number of toxic chemicals and the limited resources available to these agencies. The National Institute for Occupational Safety and Health (NIOSH) must set priorities for research on hazards encountered in the workplace. Priorities are also utilized by NIOSH in preparing criteria for recommended occupational standards which are forwarded to the Occupational Safety and Health Administration (OSHA), U.S. Department of Labor, for possible promulgation. For various reasons, including rapidly changing conditions in the American workplace, NIOSH has instituted a revised priorities program. In the future, NIOSH research and recommended standards activities will focus not only on individual chemicals, but also on industries, ...

1979-05-01

286

Nitrosamines and rubber  

Energy Technology Data Exchange (ETDEWEB)

Occupational exposure to N-nitrosamines in the rubber industry was first reported by Fajen et al. (1979). In order to study the origin and formation of nitrosamines in this industry, chemicals and industrial products, as well as the air in various working areas, were analysed. All chemicals used for rubber compounding contain nitrosamines if they are derivatives of secondary amines; e.g., tetramethylthiurame, zinc-diethyldithiocarbamate or N-oxydiethylene benzothiazolylsulfenamide. All rubber products containing these dialkyl amine derivatives exhibited considerable levels of the corresponding nitrosamines. Accordingly, variable concentrations of airborne nitrosamines could be detected at places where rubber products are manufactured or stored. The nitrosamines found correspond to the compounded chemicals. The original nitrosamine level in rubber chemicals is not high enough to explain the amounts found ...

1982-01-01

287

Modeling key cupola reactions: Behavior of carbon, silicon and manganese  

Energy Technology Data Exchange (ETDEWEB)

In the present study, models of key chemical processes governing the compositions of the tapped metal from the cupola on the basis of physico-chemical fundamentals have been developed. As evident from the literature survey, the investigations conducted in the past have focused their attention on one phenomenon at a time; for example, a particular chemical reaction, measurement of gas composition or the temperature distribution inside a cupola. Notwithstanding the importance of these studies and their contribution toward the understanding of cupola operation, mathematical models of key chemical processes and their interdependence must be investigated to obtain a complete insight into the various interlinked phenomena occurring inside a cupola. For example, the oxidation of the metallic charge leads to the formation of iron oxide which influences the final content of elements such as silicon, manganese ...

1991-01-01

288

Magnetic and chemical changes in marine sediments  

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 and diagenesis on ...

1980-05-01

289

Can we do it?  

International Nuclear Information System (INIS)

One wonders how a facility will cope with the new Clean Air Act Amendments (CAAA). Environmental engineers working in large companies' facilities and in corporate engineering groups already have an idea of how to comply with the regulations for chemical plant equipment leaks. (In fact, the rules will also affect process bins, wastewater, transfer and storage.) But those who work for smaller companies or who have assignments not directly tied to environmental affairs may not have access to the latest thinking on compliance. One of the first challenges in becoming aware of the CAAA regulations is learning the new language, which consists of acronyms, some containing other acronyms. NESHAP, for example, stands for national emissions standards for hazardous air pollutants. Prior to the CAAA, NESHAPs applied to a few specific chemicals, such as benzene. Now the proposed rules establish a HON, a hazardous organic NESHAP. According to David Gustafson, ...

290

Biological effects of low level exposures to chemicals and radiation  

International Nuclear Information System (INIS)

In May 1990 a group of scientists representing several federal agencies, the International Society of Regulatory Toxicology and Pharmacology, the private sector, and academia met to develop a strategy to encourage the study of the biological effects of low level exposures (BELLE) to chemical agents and radioactivity. A workshop was held in 1991 with seven invited speakers focusing on the toxicological implications of biological adaptations. The selection of topics and speakers was designed to consider critically the concept of hormesis, not only in a broad, conceptual manner, but also at the molecular and biochemical levels. These presentations offered a complementary perspective on the diverse range of molecular mechanisms that can become activated at low levels of toxicant exposure. In addition to chemical toxicology research, an overview of current research on 'Effects of low-dose radiation on the immune response' was presented as well as ...

291

Applicability of chemical cleaning process to steam generator secondary side, (4). Comprehensive applicability evaluation of chemical cleaning and its effect on integrity of other structural materials other than steam generator tubes  

International Nuclear Information System (INIS)

The application of chemical cleaning for dissolving and removing scale and sludge is being planned in the Japanese pressurized water reactor (PWR) plant in order to maintain high heat transfer performance and to prevent steam generator (SG) tube degradation. In this paper, the effectiveness of the Electric Power Research Institute (EPRI) and German Kraftwerk Union (KWU) processes on the integrity of structural materials other than SG tubes and the comprehensive applicability of chemical cleaning are discussed. The integrity of structural materials such as carbon steel, low-alloy steel and stainless steel was maintained after the EPRI and KWU processes. KWU chemical cleaning tailored for crevice cleaning has been studied to improve its cleaning effectiveness in crevices and to control the corrosion depth of structural materials less than the criterion for corrosion depth. (author)

2006-11-01

292

Quantitative genetic activity graphical profiles for use in chemical evaluation  

International Nuclear Information System (INIS)

A graphic approach, terms a Genetic Activity Profile (GAP), was developed to display a matrix of data on the genetic and related effects of selected chemical agents. The profiles provide a visual overview of the quantitative (doses) and qualitative (test results) data for each chemical. Either the lowest effective dose or highest ineffective dose is recorded for each agent and bioassay. Up to 200 different test systems are represented across the GAP. Bioassay systems are organized according to the phylogeny of the test organisms and the end points of genetic activity. The methodology for producing and evaluating genetic activity profile was developed in collaboration with the International Agency for Research on Cancer (IARC). Data on individual chemicals were compiles by IARC and by the US Environmental Protection Agency (EPA). Data are available on 343 compounds selected from volumes 1-53 of the IARC Monographs and on 115 ...

1990-06-27

293

Coupled modeling of non-isothermal multiphase flow, solutetransport and reactive chemistry in porous and fractured media: 1. ModelDevelopment and Validation  

Energy Technology Data Exchange (ETDEWEB)

Coupled modeling of subsurface multiphase fluid and heat flow, solute transport and chemical reactions can be used for the assessment of acid mine drainage remediation, mineral deposition, waste disposal sites, hydrothermal convection, contaminant transport, and groundwater quality. Here they present a numerical simulation model, TOUGHREACT, which considers non-isothermal multi-component chemical transport in both liquid and gas phases. A wide range of subsurface thermo-physical-chemical processes is considered. The model can be applied to one-, two- or three-dimensional porous and fractured media with physical and chemical heterogeneity. The model can accommodate any number of chemical species present in liquid, gas and solid phases. A variety of equilibrium chemical reactions is considered, such as aqueous complexation, gas dissolution/exsolution, cation ...

1998-09-01

294

The distribution profile of the chemical structural changes in ion-irradiated polyolefins  

Energy Technology Data Exchange (ETDEWEB)

The distribution profiles of the chemical structural changes induced in low density polyethylene(LDPE) irradiated by various ion-beams were obtained by micro-FT-IR measurement. Predominant species induced by ion-beam irradiation were trans-vinylene, hydroxyl group and carbonyl group. It was found that the depth profiles of these species resemble the Bragg curve, but they are rather different from the depth profile of the stopping power calculated by TRIM code. The terminal of the chemical reaction was observed to be deeper than the range calculated by TRIM code for all ion particles. This suggests that the energy profile in the region which the energy of the ion particle becomes lower is very complicated. (author).

1996-11-01

295

Technology assessment: Chlorine chemistry  

International Nuclear Information System (INIS)

Chlorine is not just one of many chemical feedstocks which is used in a few definitely harmful products like PVC or CFC but is irrelevant in all other respects. Just the opposite is true: There is hardly any product line of the chemical industry that can do without chlorine, from herbicides and pesticides to dyes, plastics, pharmaceuticals, photographic atricles, and cosmetics. Chlorine is not only a key element of chemical production but also an ubiquitous element of everyday life in civilisation. There are even many who would agree that the volume of chlorine production is an indicator of the competitive strength and national wealth of a modern society. By now, however, it has become evident that the unreflected use of chlorine is no longer ecologically acceptable. The consequences of a chlorine phase-out as compared to the continued chlorine production at the present level were investigated scientifically by a PROGNOS ...

296

TREATMENT OF RADIOACTIVE EFFLUENTS AT THE MOL LABORATORIES  

Science.gov (United States)

The cold effluents (sanitary waste and decontaminated radioactive water) are flocculated with sodium phosphate and pumped through a trickling filter. The average decontamination obtained is about 86% for alpha emittera and 76% for beta emitters. The cool effluents (activity < 10/sup -3/ mu c/ml) can be treated by several methods. Provisions have been made for two successive chemical flocculations eventually followed by an adsorptlon. The warm waste treatment (activity between 10/sup -3/ and 1 mu c/ml) is still in the experimental stage. The following methods are used: evaporation for some chemically contaminated wastes, browncoal filtration for reactor effluents, and a combination of chemical treatment and browncoal adsorption in other cases. (auth)

1959-10-31

297

Simple chemical method for nanoporous network of In2S3 platelets for buffer layer in CIS solar cells  

British Library Electronic Table of Contents (United Kingdom)

Indium sulfide thin films consisting of porous network of nanoplatelets, have been deposited using chemical bath deposition (CBD) method onto the tin-doped indium oxide (ITO) coated glass substrate. Aqueous solutions of indium sulfate and thioacetamide have been used as indium and sulfur precursors. As a complexing agent, acetic acid was used. The chemically deposited indium sulfide thin films were examined for their structural, surface morphological and optical characterizations. The X-ray diffraction analysis revealed the formation of the cubic b-In2S3 onto the substrate. From scanning electron micrograph, it is observed that the surface of substrate is covered by nanoporous platelets type morphology. The optical studies showed a direct band gap of 2.84eV for indium sulfide platelets. Ph...

2008-01-01

298

Shifts in soil organic matter composition following treatment with sodium hypochlorite and hydrofluoric acid  

British Library Electronic Table of Contents (United Kingdom)

A renewed interest in chemical fractionation of soil organic matter (SOM) originates from the premise that it enables to isolate labile SOM from SOM protected through mineral binding and recalcitrant SOM. Both selective removal of labile non-bound SOM through oxidation or hydrolysis as well as selective removal of minerals and attached SOM are often applied. Molecular-level SOM characterization by means of temperature resolved Pyrolysis-Field Ionization Mass Spectroscopy analysis (Py-FIMS) was used here as an approach to obtain insight into the fate of SOM upon wet chemical treatment with regard to composition and thermal stability. The applied sequential chemical treatment with 6% NaOCl and 10% HF yielded similar sizes in stable SOM fractions between sandy semi-native heathland and cultiv...

2009-01-01

299

Quantum adiabatic theorem for chemical reactions and systems with time-dependent orthogonalization  

CERN Document Server

A general quantum adiabatic theorem with and without the time-dependent orthogonalization is proven, which can be applied to understand the origin of activation energies in chemical reactions. Further proofs are also developed for the oscillating Schwinger Hamiltonian to establish the relationship between the internal (due to time-dependent eigenfunctions) and external (due to time-dependent Hamiltonian) time scales. We prove that this relationship needs to be taken as an independent quantum adiabatic approximation criterion. We give four examples, including logical expositions based on the spin-1/2 two-level system to address the gapped and gapless (due to energy level crossings) systems, as well as to understand how does this theorem allows one to study dynamical systems such as chemical reactions.

2011-01-01

300

PIXE analysis of chinese chicken-blood stone  

Energy Technology Data Exchange (ETDEWEB)

This paper reports the chemical compositions of chicken-blood stone Ji Xue Shi measured by Proton Induced X-ray Emission (PIXE). The experimental result show that for the red portion of chicken-blood stone, the concentration of Hg is as high as 20 wt%, and the concentration of S can be above 10 wt%. For the non-red portion the main chemical compositions are Al{sub 2}O{sub 3} and SiO{sub 2}. The obtained chemical compositions are close to those of kaolinite for Balin chicken-blood stone, and of pyrophyllite for Changhua chicken-blood stone, respectively. So far many Changhua chicken-blood stones and Balin chicken-blood stones were found in China, the PIXE method can be used to explore the provenance of available chicken-blood stones. (author)

1999-07-01

301

On the curvature in logarithmic plots of rate coefficients for chemical reactions  

Science.gov (United States)

In terms of the reduced potential energy barrier ? = ?uTS/kT, the rate coefficients for chemical reactions are usually expressed as proportional to e-?. The coupling between vibrational modes of the medium to the reaction coordinate leads to a proportionality of the regularized gamma function of Euler Q(a,?) = ?(a,?)/?(a), with a being the number of modes coupled to the reaction coordinate. In this work, the experimental rate coefficients at various temperatures for several chemical reactions were fitted to the theoretical expression in terms of Q(a,?) to determine the extent of its validity and generality. The new expression affords lower deviations from the experimental points in 29 cases out of 38 and it accounts for the curvature in the logarithmic plots of rate coefficients versus inverse temperature. In the absence of tunneling, conventional theories predict the curvature of these plots to be identically zero.

2011-05-06

302

Lithium isotope separation by cryptand (2 sub(B), 2, 1) polymer  

Energy Technology Data Exchange (ETDEWEB)

Single stage separation factors ..cap alpha.. have been determined for /sup 6/Li and /sup 7/Li between lithium ions in methanol and complexed ions with a cryptand (2 sub(B), 2, 1) polymer. The /sup 6/Li was concentrated in the cryptand. The separation factors were compared with the values of other chemical exchange systems. The maximum enrichment factor obtained was epsilon = 0.047 +- 0.002. The figure is one of the greatest in the chemical exchange reactions without valence change and almost 10 times larger than the values of ion exchangers. The variation in ..cap alpha.. depending on the chemical species was small in the non-aqueous system. High enrichment of lithium isotopes was expected to be achievable by means of the chromatographic application of the cryptand (2 sub(B), 2, 1).

1984-02-01

303

LiF enhanced nucleation of the low temperature microcrystalline silicon prepared by plasma enhanced chemical vapour deposition  

Energy Technology Data Exchange (ETDEWEB)

A 15-nm lithium fluoride (LiF) thin film evaporated on glass substrate is shown to enhance the nucleation of microcrystalline Si grown by plasma enhanced chemical vapour deposition at the amorphous/microcrystalline boundary conditions. The effect is more pronounced at low substrate temperatures, nucleation density being 10 times higher at {approx} 80 {sup o}C. The effect is ascribed to the ionic chemical nature of LiF, the low work function material used in organic electronic devices, and we propose its use for micro patterning crystalline Si regions in otherwise amorphous Si film.

2009-10-30

304

Kinetic behavior of solid particle in chemical-looping combustion: suppressing carbon deposition in reduction  

Energy Technology Data Exchange (ETDEWEB)

In order to apply chemical-looping combustion to a practical power plant, carbon deposition on the solid particle is one of the key problems to be overcome. Six kinds of solid particles were examined to clarify the kinetic behavior of carbon deposition. The effects of the solid composition, feed gas composition, and reaction temperature on carbon deposition were investigated by thermogravimetrical reactor on the basis of NiO/YSZ particle. From the viewpoints of both reactivity and resistance against carbon deposition, the particle of NiO mixed with YSZ (i.e., yttria-stabilized zirconia) was found to be a good candidate for chemical-looping combustion. It has been observed that carbon deposition could be completely avoided with very low concentration of water vapor. By means of a proposed model, the condition that carbon deposition would be avoided was identified. 12 refs., 8 figs., 2 tabs.

1998-03-01

305

Immobilization of bacteria in microgel grafted onto macroporous polyethylene  

Energy Technology Data Exchange (ETDEWEB)

The development of 'Green Chemistry' requires new materials to replace the conventional organic chemistry by biological catalysts, to produce fine chemicals in an environmentally friendly manner. Microbial whole cells can be directly used as biocatalysts, providing a simple and cheap methodology since enzyme isolation and purification are avoided. High-density polyethylene (HDPE) is a very stable polymer though it can be activated by gamma radiation to induce grafting. Glycidyl methacrylate was grafted onto macroporous HDPE and PP in the range of 1-6%, proportional to the initial monomer concentration. Grafted polymers were further chemically modified with ethylenediamine to generate a cationic hydrogel of micron-size thickness onto the internal polymer surfaces. Modified polymers were able to immobilize Gram-positive and Gram-negative bacteria that can catalyze a chemical reaction as efficient as free ...

2010-03-15

306

How to detect acidification in flowing bodies of water? Chemical and zoo-ecological indication along an acidification gradient in two brooks in the western Harz mountains  

International Nuclear Information System (INIS)

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

1991-09-24

307

Environmental assessment of proposed effluent limitations guidelines and standards for the transportation equipment cleaning category: Volume 1. Final report  

Science.gov (United States)

This environmental assessment quantifies the water quality-related benefits for Transportation Equipment Cleaning (TEC) facilities based on site-specific analyses of current conditions and the conditions that would be achieved by process changes under proposed BAT (Best Available Technology) and PSES (Pretreatment Standards for Existing Sources) controls. The US Environmental Protection Agency (EPA) estimated instream pollutant concentrations for 157 priority and nonconventional pollutants from three subcategories (barge-chemical and petroleum, rail-chemical, and truck-chemical) of direct and indirect discharges using stream dilution modeling. The potential impacts and benefits to aquatic life are projected by comparing the modeled instream pollutant concentrations to published EPA aquatic life criteria guidance or to toxic effect levels.

1998-05-01

308

Efficacy of three commercially available ballast water biocides against vegetative microalgae, dinoflagellate cysts and bacteria  

British Library Electronic Table of Contents (United Kingdom)

One proposed solution to the problem of ballast-mediated aquatic invasions involves chemically treating ballast water to kill key target organisms. Here, we examine the efficacy of three commercially available ballast water biocides using vegetative microalgae, dinoflagellate resting cysts and bacteria as test organisms. Chemicals tested were the ballast water biocides SeaKleen and Peraclean Ocean, and the chlorine dioxide biocide Vibrex. Results demonstrate that the applicability of each of the three chemical biocides as a routine ballast water treatment is limited by factors such as cost, biological effectiveness and possible residual toxicity of the discharged ballast water (assessed on the basis of impact on motility of vegetative marine microalgae). Of the three biocides tested, Perac...

2007-01-01

309

Development and validation of a CATHENA fuel channel model for a post-blowdown analysis of the high temperature thermal-chemical experiment CS28-1  

British Library Electronic Table of Contents (United Kingdom)

To form a licensing basis for a new methodology for a fuel channel safety analysis code for CANDU-6 nuclear reactor, a CATHENA model for a post-blowdown fuel channel analysis has been developed, and tested for a high temperature thermal-chemical experiment CS28-1 [Lei, Q.M., 1993. Post-test analysis of the 28-element high-temperature thermal-chemical experiment CS28-1. In: 4th International Conference on Simulation Methods in Nuclear Engineering, Montreal, PQ, 1993]. Pursuant to the objective of this investigation, the current study has focused on understanding the involved phenomena, their interrelations, and how to maintain a good accuracy of the temperature and H2 generation rate prediction without losing the important physics of the involved phenomena. The transient simulation results ...

2009-01-01

310

Decontamination of a gas-cooler by means of chemical reagent loaded foams  

Energy Technology Data Exchange (ETDEWEB)

This paper briefly describes an industrial application of the foam decontamination process applied to large volume components. The process is based on the filling of the component with liquid foam containing suitable chemical reagents, and a circulation loop enables its continuous recycling. The process was successfully validated during the decontamination of a graphite gas-cooler representing a developed area of 1000 m{sup 2}. A decontamination factor up to 190 was obtained leading to a residual activity below 1 Bq/cm{sup 2}. The process only produced 6 m{sup 3} of effluent i.e. about ten times less than for a chemical solution technique. (authors) 2 refs.

1995-12-31

311

Considerations referring to chemical descaling of filmed carbon steels  

International Nuclear Information System (INIS)

Under operational conditions in nuclear power plants, the carbon steel components of the primary and secondary circuits react with high temperature cooling agent forming several iron oxides and oxyhydroxides. These deposits can result in tubes' constrictions, pitting and intergranular corrosion and finally to heat transfer reducing and increasing of radiation fields around the circuits, as well. The descaling process involves the chemical dissolution of the corrosion deposits by means of diluted organic acidic solutions containing usually a carboxylic acid, a reductant and one or more corrosion inhibitors. To evaluate the removing rates of these superficial films two types of methods were used, the gravimetric and potentiodynamic techniques. By correlating the experimental results, we established the chemical composition of descaling solution and two models of mechanisms applicable to our specific conditions. (authors)

2009-10-12

312

Chemical state analysis of Si-base ceramics sliding materials by EPMA  

Energy Technology Data Exchange (ETDEWEB)

The purpose of the present study is to develop a new method for chemical state analysis by means of EPMA(Electron probe microanalyser). The measured X-ray intensity of Si-K{beta} characteristic X-ray spectra were read-out by a 16 bit microcomputer with a RS-232C interface. And using the curve fitting method the quantitative analysis of chemical compositions in a ternary compound that constituted of the same element has been established. The present method was applied to analyse of the friction and wear properties of Si-base ceramics sliding materials. It was found that the wear debris contains both the compositions of the sliding materials and SiO{sub 2}, and the SiO{sub 2} contents in wear debris was changed with relative humidity. The results clearly showed that the proposed method is very useful for determing the compositions in the ternary compound. (author).

1994-03-01

313

Chemical state analysis of Si-base ceramics sliding materials by EPMA  

International Nuclear Information System (INIS)

The purpose of the present study is to develop a new method for chemical state analysis by means of EPMA(Electron probe microanalyser). The measured X-ray intensity of Si-K#beta# characteristic X-ray spectra were read-out by a 16 bit microcomputer with a RS-232C interface. And using the curve fitting method the quantitative analysis of chemical compositions in a ternary compound that constituted of the same element has been established. The present method was applied to analyse of the friction and wear properties of Si-base ceramics sliding materials. It was found that the wear debris contains both the compositions of the sliding materials and SiO_2, and the SiO_2 contents in wear debris was changed with relative humidity. The results clearly showed that the proposed method is very useful for determing the compositions in the ternary compound. (author).

314

Chemical products and industrial materials; Produits chimiques et materiaux industriels  

Energy Technology Data Exchange (ETDEWEB)

A compilation of all universities, industrial and governmental agencies in Quebec which are actively involved in research and development of chemical products and industrial materials derived from biomass products, was presented. Each entry presented in a standard format that included a description of the major research activities of the university or agency, the principal technologies used in the research, available research and analytical equipment, a description of the research personnel, names, and addresses of contact persons for the agency or university. Thirty entries were presented. These covered a wide diversity of activities including biotechnological research such as genetic manipulations, bioconversion, fermentation, enzymatic hydrolysis and physico-chemical applications such as bleaching, de-inking, purification and synthesis. tabs.

1995-12-01

315

Chemical kinetic modeling of chlorinated hydrocarbons under stirred-reactor conditions  

Energy Technology Data Exchange (ETDEWEB)

The combustin of chloroethane is modeled as a stirred reactor so that we can study critical emission characteristics of the reactor as a function of residence time. We examine important operating conditions such as pressure, temperature, and equivalence ratio and their influence on destructive efficiency of chloroethane and production of other chlorinated products. The model uses a detailed chemical kinetic mechanism that we have developed previously for C{sub 3} hydrocarbons. We have added to this mechanism the chemical kinetic mechanism for C{sub 2} chlorinated hydrocarbons developed by Senkan and coworkers. Some reactions have been added to Senkan's mechanism and some of the reaction-rate expressions have been updated to reflect recent developments in the literature. In the modeling calculations, sensitivity coefficients are determined to find which reaction-rate constants have the largest effect on destructive efficiency. 25 refs., ...

1990-10-04

316

Chemical Analysis of Solid-State Irradiated Human Insulin  

British Library Electronic Table of Contents (United Kingdom)

Purpose To study the chemical modifications induced upon irradiation of solid human insulin at radiosterilization doses and investigate the influence of the absorbed dose on radiolysis. Materials and Methods Volatile radiolytic products were monitored by gas chromatography coupled with mass spectrometry (GC-MS) and non-volatile products by two different high performance liquid chromatography (HPLC) methods: the formation of higher molecular weight proteins was assessed by size exclusion liquid chromatography whereas assays for related compounds and chemical potency tests were carried out using reverse-phase HPLC-UV. Conformational changes were investigated by measurements of circular dichroism. Results After gamma irradiation at 10?kGy, the recovery of insulin was 96.8%; higher molecular w...

2006-01-01

317

Cellulose and cellulignin from sugarcane bagasse reinforced polypropylene composites: Effect of acetylation on mechanical and thermal properties  

British Library Electronic Table of Contents (United Kingdom)

This current work is concerned with the development of polypropylene composites reinforced with cellulose and cellulignin fibers attained from sugarcane bagasse. Moreover, the fibers were chemically modified by acetylating process and its effects on the fiber/matrix interaction were also evaluated. The chemical modification efficiency was verified by FTIR analysis and the fibers morphological aspects of fibers by SEM. Likewise, the influence of modified fibers content in the composites was studied by mechanical (tensile, shear and flexural tests) and thermal analyses (TGA and DSC). After the chemical modification, the FTIR results showed the appearance of acetyl groups and reduction of OH bonds for all fibers. Together with, SEM characterization showed that the acetylation changed the morp...

2008-01-01

318

Cell-mediated mutagenesis and cell transformation of mammalian cells by chemical carcinogens. [Rats, hamsters  

Science.gov (United States)

We have developed a cell-mediated mutagenesis assay in which cells with the appropriate markers for mutagenesis are co-cultivated with either lethally irradiated rodent embryonic cells that can metabolize carcinogenic hydrocarbons or with primary rat liver cells that can metabolize chemicals carcinogenic to the liver. During co-cultivation, the reactive metabolites of the procarcinogen appear to be transmitted to the mutable cells and induce mutations in them. Assays of this type make it possible to demonstrate a relationship between carcinogenic potency of the chemicals and their ability to induce mutations in mammalian cells. In addition, by simultaneously comparing the frequencies of transformation and mutation induced in normal diploid hamster cells by benzo(a)pyrene (BP) and one of its metabolites, it is possible to estimate the genetic target size for cell transformation in vitro.

1977-01-01

319

Burn-up measurement of irradiated nuclear fuel by means of micro-gamma scanning  

International Nuclear Information System (INIS)

The Cs-137 radioactivity of a neutron-irradiated nuclear fuel sample has been measured by means of a micro-gamma scanning system which is associated with a high purity Ge detector. Subsequently the burn-up has been calculated from the Cs-137 radioactivity data and then compared with the values from the theoretical computation and chemical anaylsis. The burn-up value obtained with the gamma-scanning system seems to be reasonably agreeable with that of the chemical anaylsis provided that the statistical error in the experiments is taken into account. It is revealed that the burn-up data from the theoretical approach is slightly higher than those of micro-gamma scanning and chemical analysis methods. (Author).

320

Blood gene expression markers to detect and distinguish target organ toxicity  

British Library Electronic Table of Contents (United Kingdom)

The purpose of this study was to investigate whether the expression of specific genes in peripheral blood can be used as surrogate marker(s) to detect and distinguish target organ toxicity induced by chemicals in rats. Rats were intraperitoneally administered a single, acute dose of a well-established hepatotoxic (acetaminophen) or a neurotoxic (methyl parathion) chemical. Administration of acetaminophen (AP) in the rats resulted in hepatotoxicity as evidenced from elevated blood transaminase activities. Similarly, administration of methyl parathion (MP) resulted in neurotoxicity in the rats as evidenced from the inhibition of acetyl cholinesterase activity in their blood. Administration of either chemical also resulted in mild hematotoxicity in the rats. Microarray analysis of the global ...

2010-01-01

321

Association between chemical and genetic variation in Calophyllum inophyllum, a medicinally important tree of the Western Ghats of India  

British Library Electronic Table of Contents (United Kingdom)

The objective of the present work is to study the chemical variation in Calophyllum inophyllum growing along the Western Ghats of India. Contents of dipyranocoumarins (inophyllums) in C.?inophyllum were determined to assess whether they could be used as a taxonomic marker for C.?inophyllum. This study also aims to establish inter simple sequence repeat (ISSR) markers that can be used to study genetic variation within the species and explore correlation between ISSR and chemical markers. The contents of dipyranocoumarins were estimated in seeds collected from 20 locations. Leaves from plants at the same 20 locations were assayed for ISSR variation. A dendrogram based on Nei?s genetic distance as well as principal component analysis based on dipyranocoumarins and ISSR variation clustered pla...

2011-01-01

322

An integrated oil and chemicals chain  

International Nuclear Information System (INIS)

Last year, 1991, was a difficult one for Finland's oil and chemicals company, Neste Corporation. The sharp fall in the international price of chemicals products had a significant impact on the corporation's overall result. Neste was, however, able to improve its competitive position, move ahead with numerous investments, and develop new businesses. This was particularly evident in two areas that have received significant emphasis within Neste in recent years: oil exploration and the Baltic region where a network of modern service stations in Neste livery and stretching from Vyborg on the Finnish-Russian border, through St. Petersburg, Tallinn, and the Baltic countries to Warsaw, is currently taking shape. The majority of the western-style stations in this network will be located along the route of the M12 highway, which has been dubbed the Via Baltica.

323

An evaluation of the UK skills base for toxicologists and ecotoxicologists, with focus on current and future requirements, particularly with regard to the skills required for hazard assessment of chemical substances including nanomaterials  

Environmental Research Database

Objectives1. To establish the present capacity and capability across all the sectors within the UK for - a) Undertaking research in the areas of toxicology and ecotoxicology and environmental hazard and risk assessment work on chemical subtances including emerging containments (e.g. enginerred nanomaterials); and b) Applying these skills in the policy and regulatory context. 2) The range of chemicals involved should include pharmaceutical and medical products, crop protection agents, biocides, vet [continued...]DescriptionThe aim of this project is to identify the current status of the scientific community, areas of expertise, and identify the gaps in skills, knowledge or recruitment. The project will use a questionnaire approach to obtain this information for all sectors of the business community. The analysis will identify the gaps in provision, and areas where investment is needed in future training and/or recruitment.

2009-01-15

324

Active hydrogen by chemical ionization mass spectrometry.  

Science.gov (United States)

A means of determination of a ctive hydrogen of hydroxyl, carboxyl, sulfhydryl, amino, amido and sulfonamido groups by chemical ionization mass spectrometry using ammonia and trideuterioammonia as reagent gases is described. The method is based on exchange of active hydrogen for deuterium occurring during the chemical ionization process using trideuterioammonia, with comparison of m/z for ammonium adduct [M + NH1]+ and trideuterioammonium adduct [M--nH + nD + ND4]+, or of protonated molecular ion [M + H]+ and deuteronated molecular ion [M--nH + nD + D]+ yielding the number of active hydrogens. Applications have been made to several classes of biologically important compounds. PMID:427257

1979-01-01

325

A routine chemical dosimetric system using the modified ceric sulphate dosimeter  

International Nuclear Information System (INIS)

The radiolytic reduction of the Ce4+ in a 0.8N sulfuric acid was examined, with the objective of measuring large radiation doses. the ceric sulphate dosimeter was tested in the range from 1 to 20kGy. The 0.01 M sodium oxalate solution was chosen instead of the arsenious oxide solution (used in the conventional method), in order to obtain a less expensive dosimetric system than that normally use for routine chemical dosimetry. The absorption spectrum of the Ce"4"+ solution presents an absorption peak at 370 nm; the obtained molar extinction coefficients of Ce"4"+ and Ce"3"+ were 5670 and 2.7 M"-"1 cm"-"1 respectively. The purpose of this work was to establish a simple, reliable and inexpensive routine chemical dosimetric system for high doses.

1994-10-01

326

A guide to developing and implementing safety checklists: Plant steam utilities  

British Library Electronic Table of Contents (United Kingdom)

Abstract Steam generation is an integral part of most chemical process plants; however, the steam plant often is or can be overlooked in the area of hazard analysis. The reasons for this oversight are obvious: steam generation is considered to be an old and well-understood process, and steam boiler systems are often not considered to pose the same hazards as other plant units. However, modern steam boiler systems are fueled with natural gas, pulverized coal, and/or fuel oil; each of which poses significant fire and explosion hazards. For example, a moderately sized chemical plant's boiler house may have two or three boilers operating at 240 MMBTU/hr, with each using approximately 11 ton/hr of subbituminous pulverized coal feed. Chemical plants rely on equipment design and installation, mai...

2011-01-01

327

A Combinatorial Library of Micro-Topographies and Chemical Compositions for Tailored Surface Wettability  

British Library Electronic Table of Contents (United Kingdom)

Abstract Surface modification of topography and chemistry in order to achieve a specific water contact angle (CA) has been explored by using a novel combinatorial screening platform. The screening arrays consisted of 507 distinct combinations of micro-topographies and chemical compositions. By performing chemical modifications with 1H, 1H, 2H, 2H perfluoroethyltriethoxy-silane (PFS) and n-octadecyltriethoxysilane (ODS) on standard silicon wafers it was possible to include both superhydrophobic and very hydrophilic pad arrays in the same screening platform. Surfaces modified with PFS were more hydrophobic than surfaces modified with ODS, while the unmodified silicon surfaces were hydrophilic. For the PFS modified surfaces the largest CAs were achieved with a small pillar size of X-=-1-m and...

2011-01-01

328

[Malignant transformation of human fibroblasts by neutrons and by gamma radiation: Relationship to mutations induced  

Energy Technology Data Exchange (ETDEWEB)

A brief overview if provided of selected reports presented at the International Symposium on Molecular Mechanisms of Radiation- and Chemical Carcinogen-Induced Cell Transformation held at Mackinac Island, Michigan on September 19-23, 1993.

1993-12-31

329

Zebrafish TRPA1 Channels are Required for Chemosensation but not for Thermosensation or Mechanosensory Hair Cell Function  

UK PubMed Central (United Kingdom)

Transient receptor potential (TRP) ion channels have been implicated in detecting chemical, thermal and mechanical stimuli in organisms ranging from mammals to Caenorhabditis elegans....Full Text Available

2008-10-01

330

XPS study on the correlation between chemical state and oxygen-sensing properties of an iron oxide thin film  

International Nuclear Information System (INIS)

We have studied the correlation between the chemical state and the oxygen-sensing properties of an iron oxide thin film using a setup that allows simultaneous sensor resistance measurements and X-ray photoelectron spectroscopy (XPS) data acquisition. The gas exposures were performed at the highest operating pressure of the XPS spectrometer at a controlled sample temperature which allows direct comparison between the sensor response and the chemical state of the surface. The iron oxide film was modified by a sequence of argon ion sputtering steps and the induced changes in the chemical state, resistance, and sensitivity to oxygen were investigated. The sputtering was found to reduce the iron from the Fe"3"+ to the Fe"2"+ state and to decrease the sensor resistance. The measured sensitivity to oxygen first increased by a factor of two but then collapsed to its original level. The mechanism for oxygen sensing was found to be ...

2007-10-15

331

Viewpoint: Policy Requirements for Protecting Wildlife from Endocrine Disruptors  

UK PubMed Central (United Kingdom)

Man-made endocrine-disrupting chemicals (EDCs) present a threat to biodiversity, even in remote areas. To date, numerous wildlife species have been affected by EDCs in the environment, but it is likely...Full Text Available

2006-04-01

332

Use of hydrolyzed polyacrylonitrile for limiting the influxes of water at the Sokolovgoroskiy field  

Energy Technology Data Exchange (ETDEWEB)

A formula and technology are presented for the preparation of a hydrolyzed polyacrylonitrile (gipane) from the wastes of chemical production, analysis of the results of working to use them to insulate influxes of water in the extracting wells of the Sokolovogorskiy field.

1980-01-01

333

Uranium mill tailings quarterly report, January-March 1982  

Energy Technology Data Exchange (ETDEWEB)

Progress is reported on: radon barrier systems for uranium mill tailings; liner evaluation for uranium mill tailings; revegetation/rock cover for stabilization of inactive U-tailings sites; and application of long-term chemical biobarriers for uranium tailings.

1982-05-01

334

Transport and release of chemicals from plastics to the environment and to wildlife  

UK PubMed Central (United Kingdom)

Plastics debris in the marine environment, including resin pellets, fragments and microscopic plastic fragments, contain organic contaminants, including polychlorinated biphenyls (PCBs), polycyclic...Full Text Available

2009-07-27

335

Toxicological benchmarks for screening potential contaminants of concern for effects on terrestrial plants  

International Nuclear Information System (INIS)

One of the initial stages in ecological risk assessment for hazardous waste sites is the screening of contaminants to determine which of them are worthy of further consideration as ''contaminants of potential concern.'' This process is termed ''contaminant screening.'' It is performed by comparing measured ambient concentrations of chemicals to benchmark concentrations. Currently, no standard benchmark concentrations exist for assessing contaminants in soil with respect to their toxicity to plants. This report presents a standard method for deriving benchmarks for this purpose (phytotoxicity benchmarks), a set of data concerning effects of chemicals in soil or soil solution on plants, and a set of phytotoxicity benchmarks for 34 chemicals potentially associated with US Department of Energy (DOE) sites. Chemicals that are found in soil at concentrations exceeding both the phytotoxicity benchmark and the ...

336

Toxicological benchmarks for screening potential contaminants of concern for effects on soil and litter invertebrates and heterotrophic process  

International Nuclear Information System (INIS)

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

337

Toxicity and carcinogenicity studies of boric acid in male and female B6C3F1 mice.  

UK PubMed Central (United Kingdom)

Toxicity and potential carcinogenicity studies of boric acid were investigated in mice to verify in a second rodent species that this was a noncarcinogenic chemical. Earlier chronic studies in rats...Full Text Available

1994-11-01

338

The workplace: Monitoring and prevention of occupational hazards. Volume 4  

Energy Technology Data Exchange (ETDEWEB)

This book examines the occupational health hazards imposed by neoplasms. Topics considered include: cancer as an occupational hazard; an overview; epidemiological evidence; and interaction of host and lifestyle factors with occupational chemicals in cancer causation.

1985-01-01

339

The hemoglobins of the trematodes Fasciola hepatica and Paramphistomum epiclitum: A molecular biological, physico-chemical, kinetic, and vaccination study  

UK PubMed Central (United Kingdom)

The trematode Fasciola hepatica (Fa.he.) is a common parasite of human and livestock. The hemoglobin (Hb) of Fa.he., a potential immunogen, was chosen for characterization...Full Text Available

2008-10-01

340

The control of snail hosts of bilharziasis and fascioliasis in Southern Rhodesia  

UK PubMed Central (United Kingdom)

The authors review the experimental work that has been done since the Second World War on the use of chemical molluscicides in Southern Rhodesia and describe the development of a co-operative snail...Full Text Available

1961-01-01

341

The chemical synthesis of oligoribonucleotides VII. A comparison of condensing agents in the coupling of silylated ribonucleosides.  

UK PubMed Central (United Kingdom)

The t-butyldimethylsilyl group is shown to be an ideal protecting group for the 2T-hydroxyl function of ribonucleosides during the synthesis of ribonucleotides using any of nine commonly used condensing...Full Text Available

1980-05-10

342

The Anti-Inflammatory Drug Leflunomide Is an Agonist of the Aryl Hydrocarbon Receptor  

UK PubMed Central (United Kingdom)

BackgroundThe aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates the toxicity and biological activity of dioxins and related chemicals. The...Full Text Available

343

Temperature-induced opening of TRPV1 ion channel is stabilized by the pore domain  

UK PubMed Central (United Kingdom)

SummaryTRPV1 is the founding and best-studied member of the family of temperature-activated transient receptor potential ion channels (thermoTRPs). Voltage, chemicals, and heat...Full Text Available

2010-06-01

344

Tat-Neutralizing Antibodies in Vaccinated Macaques  

UK PubMed Central (United Kingdom)

The human immunodeficiency virus Tat protein is essential for virus replication and is a candidate vaccine antigen. Macaques immunized with Tat or chemically modified Tat toxoid having the same clade...Full Text Available

2003-03-01

345

Target organs and systems: methodologies to assess immune system function.  

UK PubMed Central (United Kingdom)

Immunotoxicity encompasses both reduced and heightened immune function. Diverse chemicals can impair functioning of the immune system. Both monographs and books have been devoted to detailed descriptions...Full Text Available

1998-04-01

347

Structural, chemical and biological aspects of antioxidants for strategies against metal and metalloid exposure  

UK PubMed Central (United Kingdom)

Oxidative stress contributes to the pathophysiology of exposure to heavy metals/metalloid. Beneficial renal effects of some medications, such as chelation therapy depend at least partially on the ability...Full Text Available

2009-09-01

348

Some properties of low-mass stellar models with chemically inhomogeneous neutral-stability zones  

Energy Technology Data Exchange (ETDEWEB)

Several low-mass models with an inhomogeneous radiative core and a convective envelope are investigated, the entire core or its upper portion being treated as a zone of neutral stability. Mixing by convective overshoot will then give rise to unstable structure.

1983-03-01

349

Soluble epoxide hydrolase inhibition reveals novel biological functions of epoxyeicosatrienoic acids (EETs)  

UK PubMed Central (United Kingdom)

Early on, intriguing biological activities were found associated with the EETs using in vitro systems. Although the EETs other than the 5,6-isomer, are quite stable chemically,...Full Text Available

2007-01-01

350

Situational Analysis of Household Energy and Biomass Use and Associated Health Burden of Indoor Air Pollution and Mitigation Efforts in Pakistan  

UK PubMed Central (United Kingdom)

Biomass fuel burning leads to high levels of suspended particulate matter and hazardous chemicals in the indoor environment in countries where it is in common use, contributing significantly to indoor...Full Text Available

2010-07-01

351

Simultaneous rapid chemical synthesis of over one hundred oligonucleotides on a microscale  

UK PubMed Central (United Kingdom)

An inexpensive, extremely rapid manual method for simultaneous synthesis of large numbers of oligodeoxyribonucleotides on 50 or 150 nanomole scale is described. The oligonucleotides are assembled in...Full Text Available

1984-04-01

352

Sexual behavior in Japanese quail as a test end point for endocrine disruption: effects of in ovo exposure to ethinylestradiol and diethylstilbestrol.  

UK PubMed Central (United Kingdom)

Chemicals having a capacity to disturb the endocrine system have attracted considerable interest during recent years. There is a shortage of well-characterized in vivo tests with which to study such...Full Text Available

1999-11-01

353

Selection of reference soils for chemicals testing in the European Community  

International Nuclear Information System (INIS)

Based on an multivariate statistical evaluation of binary and metric data relating to the soil cover of the European Community five regionally representative reference soils (EURO-Soils) have been identified for chemicals testing in the EC. The soil material sampled at representative localities in Italy, Greece, Great Britain, France and Germany was treated and prepared according to OECD Test Guideline 106 and analysed in detail. The homogenised specimens were subject to an EC-wide ring test to evaluate the feasibility of the modified guideline and to validate the physical-chemical amenability of the reference soils for sorption tests. The results proved the validity of the soils selected for assessing the potential behaviour of new chemicals in soil on the basis of a comparative evaluation of the individual test results obtained. In the light of this parametric assessment potential test soils were subsequently identified ...

354

Selected Physical and Chemical Properties of Feverfew (Tanacetum parthenium) Extracts Important for Formulated Product Quality and Performance  

UK PubMed Central (United Kingdom)

The objectives of this research are: (1) to assess selected formulation-relevant physical properties of several commercial Feverfew extracts, including flowability, hygroscopicity, compressibility and...Full Text Available

355

STS-94 - Johnson Space Center - NASA  

Science.gov (United States)

spacecraft and aircraft propulsion, and hazardous waste disposal. .... called lockers and two larger, standardized compartments called drawers. ..... ductile refractory metal used chiefly in nuclear reactors and chemical processing ...

356

STS-83 - Johnson Space Center - NASA  

Science.gov (United States)

Radiation Measurement in Crew Compartment. DTO 805: .... spacecraft and aircraft propulsion, and hazardous waste disposal. ...... combustion reactions in a turbulent chemical kinetic flow reactor using laser induced fluorescence and ...

358

Research progress in the electrochemical synthesis of ferrate(VI)  

International Nuclear Information System (INIS)

There is renewed interest in the +6 oxidation state of iron, ferrate (VI) (FeVIO42-), because of its potential as a benign oxidant for organic synthesis, as a chemical in developing cleaner ('greener') technology for remediation processes, and as an alternative for environment-friendly battery cathodes. This interest has led many researchers to focus their attention on the synthesis of ferrate(VI). Of the three synthesis methods, electrochemical, wet chemical and thermal, electrochemical synthesis has received the most attention due to its ease and the high purity of the product. Moreover, electrochemical processes use an electron as a so-called clean chemical, thus avoiding the use of any harmful chemicals to oxidize iron to the +6 oxidation state. This paper reviews the development of electrochemical methods to synthesize ferrate(VI). The approaches chosen by different laboratories to overcome some of ...

2009-04-01

359

Regulation of Energy Metabolism Pathways by Estrogens and Estrogenic Chemicals and Potential Implications in Obesity Associated with Increased Exposure to Endocrine Disruptors  

UK PubMed Central (United Kingdom)

The prevalence of obesity among children, adolescents and adults has been dramatically increasing worldwide during the last several decades. The obesity epidemic has been recognized as one of...Full Text Available

2009-07-01

360

Red mud as a catalyst for coal liquefaction  

Energy Technology Data Exchange (ETDEWEB)

In order to replace industrial cobalt and nickel and molybdenum catalysts, more economical catalysts, red muds, are used. Comparative data about the chemical, structural and thermal properties of different samples of red muds, which are important for catalytic hydrogenation, are cited. The different conditions for hydrogenation of coals in a reactor are examined.

1983-01-01

361

Receptor mechanisms and dose-response models for the effects of dioxins.  

UK PubMed Central (United Kingdom)

There is increasing evidence that receptor-mediated events impact one or more stages responsible for tumor development in experimental animals and humans. Although many chemicals and endogenous hormones...Full Text Available

1993-04-22

362

Recent Applications of DNA Microarray Technology to Toxicology and Ecotoxicology  

UK PubMed Central (United Kingdom)

Gene expression is a unique way of characterizing how cells and organisms adapt to changes in the external environment. The measurements of gene expression levels upon exposure to a chemical can be...Full Text Available

2006-01-01

363

Reactivity parameters in structure-activity relationship-based risk assessment of chemicals.  

UK PubMed Central (United Kingdom)

New approaches to the risk assessment process are needed that might be more definitive and satisfying to the scientific community, interest groups, and the public at large. This commentary examines...Full Text Available

1996-08-01

364

Purification and properties of penicillinases from two strains of Bacillus licheniformis: a chemical, physicochemical and physiological comparison  

UK PubMed Central (United Kingdom)

1. The penicillinases formed by penicillinase-constitutive mutant strains from two closely related varieties (749 and 6346) of Bacillus licheniformis have been isolated, characterized...Full Text Available

1965-03-01

365

Protection against chemical-induced lung injury by inhibition of pulmonary cytochrome P-450.  

UK PubMed Central (United Kingdom)

Protection afforded by trialkyl phosphorothionates against the lung injury caused by trialkyl phosphorothiolates probably results from the inhibition by the P = S moiety of the thionates, of one or...Full Text Available

1990-04-01

366

Process and apparatus for chemically removing ash from coal  

Science.gov (United States)

Finely divided ash-containing coal is immersed in an aqueous solution of hydrochloric acid or citric acid, and acidic ammonium fluoride to cause the ash to react with the acid and the acidic ammonium fluoride, and the deashed coal is thereafter separated from the solution.

1984-01-03

367

Prevention of chain cleavage in the chemical synthesis of 2'-silylated oligoribonucleotides.  

UK PubMed Central (United Kingdom)

Strong aqueous ammonium hydroxide used to remove N-acyl protecting groups from synthetic oligoribonucleotides causes removal of some alkylsilyl protecting groups from 2'-hydroxyls and leads to chain...Full Text Available

1989-05-11

368

Preparation and biological properties of a novel composite scaffold of nano-hydroxyapatite/chitosan/carboxymethyl cellulose for bone tissue engineering  

UK PubMed Central (United Kingdom)

In this study, we report the physico-chemical and biological properties of a novel biodegradable composite scaffold made of nano-hydroxyapatite and natural derived polymers of chitosan and carboxymethyl...Full Text Available

369

Predictions for the outcome of rodent carcinogenicity bioassays: identification of trans-species carcinogens and noncarcinogens.  

UK PubMed Central (United Kingdom)

Thirty chemicals or substances currently undergoing long-term carcinogenicity bioassays in rodents have been used in a project to further evaluate methods and information that may have the capability...Full Text Available

1996-10-01

370

Powdering Characteristics of a Thin Film Evaporator: Drying and Powdering of a Solution.  

Science.gov (United States)

A thin-film evaporator requires only a short heating time to concentrate a solution since it has a high thermal efficiency and has a small capacity. Thus, the chemical industry often uses this type of evaporator for concentrating materials that are subjec...

1983-01-01

371

Possible preparation of wood-plastic materials based on unsaturated polyester resins and methyl metacrylate, by radiation and chemical methods in combination  

Energy Technology Data Exchange (ETDEWEB)

The preparation of wood-plastic combinations (WPC) using combined methods for curing intermediate products and final products is described. In the first step, impregnated wood was irradiated using doses of 1 to 10 kGy in the presence of chemical initiators of polymerization. Thereafter, curing of this partly cured impregnating mixture was accomplished in the wood at elevated temperatures with the aid of chemical initiators of polymerization. Impregnation mixtures based on unsaturated polyester resins and methyl methacrylate, and the wood species European Beech (Fagus silvatica) and Black Alder (Alnus glutinosa) were used. The results indicate that this method of preparing WPC allows substantially lower radiation doses to be used, i.e., doses in the range of 1 to 2.5 kGy. These doses gelatinate the impregnation mixture in the wood so that the subsequent curing by chemical polymerization initiators proceeds without the ...

1982-04-01

372

Possible preparation of wood-plastic materials based on unsaturated polyester resins and methyl metacrylate, by radiation and chemical methods in combination  

International Nuclear Information System (INIS)

The preparation of wood-plastic combinations (WPC) using combined methods for curing intermediate products and final products is described. In the first step, impregnated wood was irradiated using doses of 1 to 10 kGy in the presence of chemical initiators of polymerization. Thereafter, curing of this partly cured impregnating mixture was accomplished in the wood at elevated temperatures with the aid of chemical initiators of polymerization. Impregnation mixtures based on unsaturated polyester resins and methyl methacrylate, and the wood species European Beech (Fagus silvatica) and Black Alder (Alnus glutinosa) were used. The results indicate that this method of preparing WPC allows substantially lower radiation doses to be used, i.e., doses in the range of 1 to 2.5 kGy. These doses gelatinate the impregnation mixture in the wood so that the subsequent curing by chemical polymerization initiators proceeds without the ...

1982-01-01

373

Phytoremediation Potential of Lead-Contaminated Soil Using Tropical Grasses  

Science.gov (United States)

The global problem concerning contamination of the environment because of human activities is increasing. Most of the environmental contaminants are chemical by-products and heavy metals such as lead (Pb). Lead released into the environment makes its way into the air, soil and water. Lead contribute...

374

Photoelectron spectroscopy of carbonyls: benzoic acid and its derivatives  

Energy Technology Data Exchange (ETDEWEB)

The ultraviolet photoelectron spectra of benzoic acid and 20 of its derivatives are presented. The low-energy regions of these spectra are deconvoluted and assigned using chemical substitution effects. 5 figures, 3 tables.

1981-01-01

375

Occupational health priorities for health standards: the current NIOSH approach.  

UK PubMed Central (United Kingdom)

Government agencies responsible for protecting the public from the adverse effects of toxic chemicals must set priorities for research, regulatory action, protocol testing, and monitoring due to the...Full Text Available

1979-05-01

376

Molecular mechanisms of genetic adaptation to xenobiotic compounds.  

UK PubMed Central (United Kingdom)

Microorganisms in the environment can often adapt to use xenobiotic chemicals as novel growth and energy substrates. Specialized enzyme systems and metabolic pathways for the degradation of man-made...Full Text Available

1992-12-01

377

Molecular basis of the inhibition of human aromatase (estrogen synthetase) by flavone and isoflavone phytoestrogens: A site-directed mutagenesis study.  

UK PubMed Central (United Kingdom)

Flavone and isoflavone phytoestrogens are plant chemicals and are known to be competitive inhibitors of cytochrome P450 aromatase with respect to the androgen substrate. Aromatase is the enzyme that...Full Text Available

1998-02-01

378

Modeling of soluble impurities distribution in the steam generator secondary water  

Energy Technology Data Exchange (ETDEWEB)

A model was developed to compute concentration of impurities in the WWER 440 steam generator (SG) secondary water along the tube bundle. Calculated values were verified by concentration values obtained from secondary water sample chemical analysis. (orig.). 2 refs.

1997-12-31

379

Mitochondrial DNA Damage and Animal Longevity: Insights from Comparative Studies  

UK PubMed Central (United Kingdom)

Chemical reactions in living cells are under strict enzyme control and conform to a tightly regulated metabolic program. However, uncontrolled and potentially deleterious endogenous reactions occur,...Full Text Available

380

Minimal Curvature Trajectories: Riemannian Geometry Concepts for Model Reduction in Chemical Kinetics  

CERN Document Server

In dissipative ordinary differential equation systems different time scales cause anisotropic phase volume contraction along solution trajectories. Model reduction methods exploit this for simplifying chemical kinetics via a time scale separation into fast and slow modes. The aim is to approximate the system dynamics with a dimension-reduced model after eliminating the fast modes by enslaving them to the slow ones via computation of a slow attracting manifold. We present a novel method for computing approximations of such manifolds using trajectory-based optimization. We discuss Riemannian geometry concepts as a basis for suitable optimization criteria characterizing trajectories near slow attracting manifolds and thus provide insight into fundamental geometric properties of multiple time scale chemical kinetics. The optimization criteria correspond to a suitable mathematical formulation of "minimal relaxation" of chemical ...

2009-01-01

381

Maximum workplace concentration values and carcinogenicity classification for mixtures.  

UK PubMed Central (United Kingdom)

In Germany, the Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area (MAK Commission) generally sets maximum workplace concentration values (i.e., a proposed occupational...Full Text Available

1998-12-01

382

Marine Ecosystem Analysis for Wolsung Nuclear Power Plant.  

Science.gov (United States)

Environmental surveys to provide base-line data for assessing the potential impact of the operation of Wolseong NPP on marine ecosystems were performed at 3-month intervals in 1981. Physico-chemical properties of seawater and gross beta activities in seaw...

1982-01-01

383

Mapping Drug Physico-Chemical Features to Pathway Activity Reveals Molecular Networks Linked to Toxicity Outcome  

UK PubMed Central (United Kingdom)

The identification of predictive biomarkers is at the core of modern toxicology. So far, a number of approaches have been proposed. These rely on statistical inference of toxicity response from either...Full Text Available

384

Macrophage induction of T-suppressor cells in pesticide-exposed and protozoan-infected mice.  

UK PubMed Central (United Kingdom)

The use of infectious pathogens has allowed the detection of the development of synergism between pathogens and ubiquitous environmental chemical contaminants. This synergism has been demonstrated to...Full Text Available

1982-02-01

385

Long-lived quantum coherence in photosynthetic complexes at physiological temperature  

UK PubMed Central (United Kingdom)

Photosynthetic antenna complexes capture and concentrate solar radiation by transferring the excitation to the reaction center that stores energy from the photon in chemical bonds. This process occurs...Full Text Available

2010-07-20

386

Local and regional ozone production: Chemistry and transport  

International Nuclear Information System (INIS)

The EUROTRAC sub-project ''Tropospheric Ozone Research'' (TOR) follows a dual strategy: - Observation of the chemical processes contributing to the oxygen balance directly in the atmosphere; - Establishment of a validated data base for model calculations. Both tasks require simultaneous measurements of a wide range of chemical and meteorological components. In the case of the investigation of the chemical processes, it is also desirable to measure the free radicals directly involved in ozone production. In the project described, a measuring station was set up. For a period of two years and a half, continuous measurements were made of ozone and its chemical precursors (NO, NO_2, NO_y, VOC, CO), as well as other photooxidants (H_2O_2 and organic hydroperoxides, organic nitrates), the photolysis frequency of NO_2, and meteorological parameters (wind, temperature, moisture, aerosols). The station was ...

387

Lipotoxic heart disease in obese rats: Implications for human obesity  

UK PubMed Central (United Kingdom)

To determine the mechanism of the cardiac dilatation and reduced contractility of obese Zucker Diabetic Fatty rats, myocardial triacylglycerol (TG) was assayed chemically and morphologically. TG was...Full Text Available

2000-02-15

388

LITERATURE SURVEY OF THE CORROSION BEHAVIOR OF TANTALUM, ZIRCONIUM, AND TITANIUM  

Science.gov (United States)

The corrosion behavior of Ta, Ti, and Zr in inorganic acids, bases, chlorides and miscellaneous salts, waters and gases, and organic acids and miscellaneous organic chemicals is summarized. (W.L.H)

1955-02-23

389

Isotopic composition of elements in extra-terrestrial materials 1  

Energy Technology Data Exchange (ETDEWEB)

The present review focuses on the isotropic composition in extra-terrestrial materials. There are many different factors in the variation in isotopic abundance between terrestrial and extra-terrestrial materials. Major factors in unusual isotopic composition are roughly grouped into three categories: factors associated with fractionation of isotopes, nuclear reaction or radioactive disintegration. Fractionation takes place due to differences in mass among various isotopes. There are physical and chemical factors. Physical ones include vaporization and condensation which meteorites may experience during their formation while the chemical ones include chemical reactions and chemical equilibration. There phenomena are mentioned as factors in the variation in isotopic ratio which is associated with nuclear reactions. An important nuclear reaction is the formation of elements that has been occurring ...

1989-02-01

390

Isolation and identification of a cobamide coenzyme from the tapeworm Spirometra mansonoides.  

Science.gov (United States)

A light-sensitive vitamin B12 derivative has been extracted from the adult cestode, Spirometra mansonoides. This corrinoid was identified as the cobamide coenzyme, adenosylcobalamin, by its chromatographic, chemical, and spectral properties. PMID:1003284

1976-12-01

391

Influence of antioxidants on service life of high speed ball bearings lubrication; Einfluss von Antioxidantien auf die Schmierfettgebrauchsdauer in schnelllaufenden Waelzlagern  

Energy Technology Data Exchange (ETDEWEB)

Under severe operating conditions, such as starved lubrication, performance, service life, and reliability of rolling element bearings depend on the chemical and physical interactions between the contacting surfaces, the lubricant components, and the atmosphere. The IMKT{sup 1}, PI{sup 2}, and the imt{sup 3} have been cooperating on systematic investigations of interfacial interactions in high speed grease lubricated ball bearings. These include long time tests with complete bearings lubricated with greases of different composition under defined operating conditions, conducted at the IMKT, and chemical and physical characterizations of the running surfaces at the PI and imt. At the PI, in particular the chemical nature of the boundary layers has been investigated with time of flight secondary ion mass spectrometry (TOF-SIMS). The imt has been involved in the investigations by measuring the physical/mechanical properties of ...

2004-07-01

392

Industrial emissions cause extreme urban ozone diurnal variability  

UK PubMed Central (United Kingdom)

Simulations with a regional chemical transport model show that anthropogenic emissions of volatile organic compounds and nitrogen oxides (NOx = NO + NO2) lead to a dramatic diurnal...Full Text Available

2004-04-27

393

Impact of oil and related chemicals on the marine environment  

International Nuclear Information System (INIS)

This review updates a previous review entitled ''Impact of Oil on the Marine Environment''. It covers oil and individual hydrocarbons, used lubricating oils, chemical control agents for oil spills, and wastes from offshore petroleum operations. It considers all major knowledge generated since the mid-1970s. The review covers its topics comprehensively, from a consideration of the composition, sources and inputs of oil to its ecological and human health effects and its effects on man's use of the sea. The review addresses several key questions on the present levels of contamination, the impact of hydrocarbons and related chemicals on marine biota, the recovery potential of marine ecosystems exposed to these contaminants, the degree of protection required for marine ecosystems known to be vulnerable and sensitive, and recommended research and other actions to fill gaps in knowledge. The review describes the hazards of marine oil pollution and ...

394

Identification of inhibitors of auxin transcriptional activation by means of chemical genetics in Arabidopsis  

UK PubMed Central (United Kingdom)

Auxin modulates diverse plant developmental pathways through direct transcriptional regulation and cooperative signaling with other plant hormones. Genetic and biochemical approaches have clarified...Full Text Available

2004-10-12

395

Identification of a Chemically Induced Point Mutation Mediating Herbicide Tolerance in Annual Medics (Medicago spp.)  

UK PubMed Central (United Kingdom)

Background and AimsSulfonylurea (SU) herbicides are used extensively in cereal–livestock farming zones as effective and cheap herbicides with useful levels of residual activity....Full Text Available

2008-05-01

396

Hydrogen production from coal using coal direct chemical looping and syngas chemical looping combustion systems: Assessment of system operation and resource requirements  

Energy Technology Data Exchange (ETDEWEB)

Coal direct chemical looping (CDCL) substitutes the gasification process in syngas chemical looping (SCL), thus eliminating the need for higher oxygen consumption. In this study, operating conditions are assessed for CDCL and SCL, directed towards hydrogen production from coal. The main objective is to increase the overall H{sub 2}/CO{sub 2} ratio for a given amount of coal, based on the various conditions. The operating variables considered as part of a resource optimization analysis include: (i) inlet conditions to the primary reactors, (ii) minimum resource requirements (air, steam and iron oxide), (iii) hydrogen-to-component ratios, and (iv) effect of coal carrier gas. The results suggest that CDCL has a higher hydrogen-to-CO{sub 2} ratio than SCL along with advantages such as low overall resource requirements (steam and air) and fewer intermediate processes. The coal carrier gas affects the hydrogen production only in the SCL system by ...

2009-03-15

397

Human variability and susceptibility to trichloroethylene.  

UK PubMed Central (United Kingdom)

Although humans vary in their response to chemicals, comprehensive measures of susceptibility have generally not been incorporated into human risk assessment. The U.S. EPA dose-response-based risk assessments...Full Text Available

2000-05-01

398

How to overestimate risks of ionizing radiations  

International Nuclear Information System (INIS)

Ignoring the numerous, known and mainly unknown, interactions between chemicals and ionizing radiations, causes strong controversy about the risks of ionizing radiations. Yet the best known interactions between chemicals and radiations is that between radon and tobacco smoke. Although it is and it will be always impossible to derive quite quantitative laws for this interaction, it has been possible to derive some semi-quantitative relationships based on reasonable assumptions and statistics on lung cancer deaths in developed countries. They show that ignoring the dangers of tobacco smoking as we did still long after we had recognised the dangers of radiations, could asses to radiations thirty or forty times more risks than reality. As present world is flown by tens of thousands chemicals, little or not present in a natural environment, and as it would be very surprising that some hundreds of these do not behave like those ...

399

Host plant shifts affect a major defense enzyme in Chrysomela lapponica  

UK PubMed Central (United Kingdom)

Chrysomelid leaf beetles use chemical defenses to overcome predatory attack and microbial infestation. Larvae of Chrysomela lapponica that feed on willow sequester plant-derived salicin...Full Text Available

2011-03-22

400

Gyrase B Inhibitor Impairs HIV-1 Replication by Targeting Hsp90 and the Capsid Protein*  

UK PubMed Central (United Kingdom)

Chemical genetics is an emerging approach to investigate the biology of host-pathogen interactions. We screened several inhibitors of ATP-dependent DNA motors and detected the gyrase B inhibitor coumermycin...Full Text Available

2010-12-10

401

Free radical mediated cell toxicity by redox cycling chemicals.  

UK PubMed Central (United Kingdom)

Free radical formation has been implicated in the toxicity of a wide range of xenobiotics. In recent years, particular interest has been paid to compounds which can undergo a one electron reduction...Full Text Available

1987-06-01

402

FLOCCULATION-FLOTATION AIDS FOR TREATMENT OF COMBINED SEWER OVERFLOWS  

Science.gov (United States)

The objectives of this study were to investigate the flocculation/flotation characteristics of combined sewer overflow through laboratory and field testing. The concept involves the introduction of chemicals and buoyant flotation aids into the overflow and the subsequent cofloccu...

403

Effects of pH, Temperature, and Nutrients on Propionate Degradation by a Methanogenic Enrichment Culture  

UK PubMed Central (United Kingdom)

Enrichment cultures were used to determine the conditions promoting fastest methanogenic propionate degradation and growth by adapting the cultures to various physical and chemical conditions and measuring...Full Text Available

1987-07-01

404

Effects of noise and electromagnetic fields on reproductive outcomes.  

UK PubMed Central (United Kingdom)

Much public health research has been directed to studies of cancer risks due to chemical agents. Recently, increasing attention has been given to adverse reproductive outcomes as another, shorter-term...Full Text Available

1989-05-01

405

Effects of exposure to low concentrations of chlorinated hydrocarbons on the kidney and liver of industrial workers.  

UK PubMed Central (United Kingdom)

An assessment has been made of biochemical alterations in renal and hepatic functions of 73 male operators employed for an average of 8.2 years (range 0.5-23 years) in a chemical plant producing chlorinated...Full Text Available

1993-04-01

406

EPR dosimetry in chemically treated fingernails  

UK PubMed Central (United Kingdom)

By using EPR measurements of radiation-induced radicals it is possible to utilize human fingernails to estimate radiation dose after-the-fact. One of the potentially limiting factors in this...Full Text Available

2007-08-01

407

EPA On-line Tools for Site Assessment Calculation | Ecosystems...  

Science.gov (United States)

MWo = average molecular weight of fuel est. 105 g/mole for gasoline est. 165 g/mole for Jet fuel est. 230 g/mole for diesel fuel MWX = molecular weight of selected chemical...

2011-01-19

408

Dynamics of ligand substitution in labile cobalt complexes resolved by ultrafast T-jump  

UK PubMed Central (United Kingdom)

Ligand exchange of hydrated metal complexes is common in chemical and biological systems. Using the ultrafast T-jump, we examined this process, specifically the transformation of aqua cobalt (II) complexes...Full Text Available

2008-09-02

409

Direct chemical information from special radiotracers as well as from outer X-ray excitation  

Energy Technology Data Exchange (ETDEWEB)

Radionuclides exhibiting in decaying a strong interaction between nucleus and electron shell (especially electron capture and internal conversion) are, in principle, sensitive to their chemical surroundings. Consequently, they can be used to yield chemical information after an appropriate labelling procedure. The information can be extracted from the decay rate variation as well as from their X-ray emission as a response to an inner-shell vacancy creation during nuclear deexcitation. As an example of the former method the relationship between the decay rate of /sup 99m/Tc and the chemical structures of pertechnetate and bis(meso-dimercapto-succinate)oxotechnetate(V) is considered. Lower expectations with respect to measuring techniques are associated with the observation of X-ray emission. For a number of elements (especially 3d transition elements) the K/sub ..cap alpha..//K/sub ..beta../ X-ray intensity ratio was found to ...

1983-09-01

410

Direct chemical information from special radiotracers as well as from outer X-ray excitation  

International Nuclear Information System (INIS)

Radionuclides exhibiting in decaying a strong interaction between nucleus and electron shell (especially electron capture and internal conversion) are, in principle, sensitive to their chemical surroundings. Consequently, they can be used to yield chemical information after an appropriate labelling procedure. The information can be extracted from the decay rate variation as well as from their X-ray emission as a response to an inner-shell vacancy creation during nuclear deexcitation. As an example of the former method the relationship between the decay rate of /sup 99m/Tc and the chemical structures of pertechnetate and bis(meso-dimercapto-succinate)oxotechnetate(V) is considered. Lower expectations with respect to measuring techniques are associated with the observation of X-ray emission. For a number of elements (especially 3d transition elements) the K/sub #alpha#//K/sub #betta#/ X-ray intensity ratio was found to be an ...

1982-10-01

411

Development of compression-controlled low-level laser probe system: towards clinical application  

UK PubMed Central (United Kingdom)

Various physico-chemical tissue optical clearing (TOC) methods have been suggested to maximize photon density in tissue. In order to enhance photon density, a compression-controlled low-level...Full Text Available

2010-09-01

412

Development and testing of a technology for insulating influx of stratum waters into producing wells with the use of a copolymer of methacrylic acid and diethyl ammonium salt  

Energy Technology Data Exchange (ETDEWEB)

Cited are the results of physico-chemical studies and industrial tests of a copolymer of methacrylic acid and diethylammonium salt, used for limiting the influx of stratum waters into a well.

1981-01-01

413

Determining insoluble impurities in spent sulfuric acid from the production of synthetic alcohols  

Energy Technology Data Exchange (ETDEWEB)

Ammonium sulfate is produced from spent sulfuric acid from the production of alcohols. Certain mineral and organic impurities exist in the sulfuric acid that impair the quality of the ammonium sulfate. A detailed method for the chemical analysis for the impurities is presented.

1983-01-01

415

Core Synthesis Facility: Bridging the Gap between Chemistry and Biology  

UK PubMed Central (United Kingdom)

CF-23“The biggest stumbling block for biological sciences turned out to be synthetic organic chemistry” – Elias A. Zerhouni, Former NIH Director in Chemical...Full Text Available

2010-09-01

416

Cooperative research in coal liquefaction infratechnology and generic technology development  

Energy Technology Data Exchange (ETDEWEB)

Cooperative research in coal liquefaction from Auburn University, University of Kentucky, University of Pittsburgh, West Virginia University, University of Utah, and the UK Center for Applied Energy Research, are briefly discussed. Topics covered include desulfurization, chemical reactivity, coprocessing, and catalysis. (CBS)

1989-01-01

417

Comparison of estimation capabilities of response surface methodology (RSM) with artificial neural network (ANN) in lipase-catalyzed synthesis of palm-based wax ester  

UK PubMed Central (United Kingdom)

BackgroundWax esters are important ingredients in cosmetics, pharmaceuticals, lubricants and other chemical industries due to their excellent wetting property. Since the naturally...Full Text Available

418

Comparative aspects of pesticide metabolism in plants and animals.  

UK PubMed Central (United Kingdom)

Pesticide chemicals are an important component of modern agriculture. Through their use, plants and animals are exposed to pesticides directly and indirectly from transport through soil, water, and...Full Text Available

1978-12-01

419

Cloning and sequencing of a dehalogenase gene encoding an enzyme with hydrolase activity involved in the degradation of gamma-hexachlorocyclohexane in Pseudomonas paucimobilis.  

UK PubMed Central (United Kingdom)

In Pseudomonas paucimobilis UT26, gamma-hexachlorocyclohexane (gamma-HCH) is converted by two steps of dehydrochlorination to a chemically unstable intermediate, 1,3,4,6-tetrachloro-1,4-cyclohexadiene...Full Text Available

1993-10-01

420

Chemical refining of coal (Report on ECSC contract 7220-EC/816)  

Energy Technology Data Exchange (ETDEWEB)

Three areas have been investigated: coal liquefaction with supercritical fluids, liquefaction by extraction with high boiling liquid solvents, and the production of resins from coal-derived hydrocarbons. The processes are described.

1983-01-01

421

Chemical process equipment for Hitachi. ; Featured equipment  

Energy Technology Data Exchange (ETDEWEB)

The present article describes the specialities in various chemical process equipment fabricated by Hitachi. It introduces the thin-film evaporator which heats, vaporizes and concentrates high viscosity fluid and slurry under thin-film conditions, the centrifugal extractor which uses a high speed rotating rotor to separate two kinds of immiscible liquids effectively in counter current contact conditions under a gravitational force ranging from 2,000G to 4,500G, the process gas boiler and heat pipe equipment which recovers exhausted heat effectively from various plants, the furnace and quench systems which are applied to olefin plants, EDC cracking and steam reforming, and the equipment which has been supplied to chemical plants operated under severe conditions, such as high temperature, high pressure and corrosive atmosphere. It was demonstrated that these technologies and know-hows accumulated from Hitachi's extensive experiences in ...

1993-01-01

422

Chemical contaminants on DOE lands and selection of contaminant mixtures for subsurface science research  

Energy Technology Data Exchange (ETDEWEB)

This report identifies individual contaminants and contaminant mixtures that have been measured in the ground at 91 waste sites at 18 US Department of Energy (DOE) facilities within the weapons complex. The inventory of chemicals and mixtures was used to identify generic chemical mixtures to be used by DOE's Subsurface Science Program in basic research on the subsurface geochemical and microbiological behavior of mixed contaminants (DOE 1990a and b). The generic mixtures contain specific radionuclides, metals, organic ligands, organic solvents, fuel hydrocarbons, and polychlorinated biphenyls (PCBs) in various binary and ternary combinations. The mixtures are representative of in-ground contaminant associations at DOE facilities that are likely to exhibit complex geochemical behavior as a result of intercontaminant reactions and/or microbiologic activity stimulated by organic substances. Use of the generic mixtures will focus research ...

1992-04-01

423

Chemical complementation: A reaction-independent genetic assay for enzyme catalysis  

UK PubMed Central (United Kingdom)

A high-throughput assay for enzyme activity has been developed that is reaction independent. In this assay, a small-molecule yeast three-hybrid system is used to link enzyme catalysis to transcription...Full Text Available

2002-12-24

424

Challenges of functional imaging research of pain in children  

UK PubMed Central (United Kingdom)

Functional imaging has revolutionized the neurosciences. In the pain field it has dramatically altered our understanding of how the brain undergoes significant functional, anatomical and chemical changes...Full Text Available

425

Cells navigate with a local-excitation, global-inhibition-biased excitable network  

UK PubMed Central (United Kingdom)

Cells have an internal compass that enables them to move along shallow chemical gradients. As amoeboid cells migrate, signaling events such as Ras and PI3K activation occur spontaneously on pseudopodia....Full Text Available

2010-10-05

426

Cell behaviour on chemically microstructured surfaces  

Energy Technology Data Exchange (ETDEWEB)

Micropatterned surfaces with different chemical topographies were synthesised in order to investigate the influence of surface chemistry and topography on cell behaviour. The microstructured materials were synthesised by photoimmobilising natural Hyaluronan (Hyal) and its sulphated derivative (HyalS), both adequately functionalised with a photorective moiety, on glass substrates. Four different grating patterns (10, 25, 50 and 100 {mu}m) were used to pattern the hyaluronan. The micropatterned samples were analysed by Secondary Ions Mass Spectrometry, Scanning Electron Microscopy (SEM) and Atomic Force Microscopy to investigate the chemistry and the topography of the surfaces. The spectroscopic and microscopic analysis of the microstructured surfaces revealed that the photoimmobilisation process was successful, demonstrating that the photomask patterns were well reproduced on the sample surface. The influence of chemical topographies on the cell ...

2003-03-03

427

CERES BDS Quality Summaries - Atmospheric Science Data Center - NASA  

Science.gov (United States)

Nov 18, 2010 ... Roughly speaking, the fidelity interval we quote is a "3 sigma" value. ... surface of the foremost quartz filter which is then chemically altered by ... ( CERES) scanner point accuracy using a coastline detection system", ...

428

Biomarkers Signal Contaminant Effects on the Organs of English Sole (Parophrys vetulus) from Puget Sound  

UK PubMed Central (United Kingdom)

Fish living in contaminated environments accumulate toxic chemicals in their tissues. Biomarkers are needed to identify the resulting health effects, particularly focusing on early changes at a subcellular...Full Text Available

2006-06-01

429

Big bang nucleosynthesis  

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.

1999-01-01

430

Bacterial response to siderophore and quorum-sensing chemical signals in the seawater microbial community  

UK PubMed Central (United Kingdom)

BackgroundOceans are iron-deficient and nutrient-poor environments. These conditions impart limitations on our understanding of and our ability to identify microorganisms from the...Full Text Available

431

Atomic Energy of Canada Limited-Chemical Company Annual Review of Operations, 1980-81.  

Science.gov (United States)

Record production of heavy water was achieved: the plants at Glace Bay and Port Hawkesbury, Nova Scotia, produced a total of 560 megagrams. A shipment of 500 Mg was delivered on time to the Wolsung CANDU reactor in Korea. Energy conservation and waste hea...

1981-01-01

432

Analytical validation of accelerator mass spectrometry for pharmaceutical development  

UK PubMed Central (United Kingdom)

The validation parameters for pharmaceutical analyses were examined for the accelerator mass spectrometry measurement of 14C/C ratio, independent of chemical separation procedures....Full Text Available

2010-03-01

433

An overview of prechronic and chronic toxicity/carcinogenicity experimental study designs and criteria used by the National Toxicology Program.  

UK PubMed Central (United Kingdom)

Since the establishment of the National Toxicology Program (NTP), there have been gradual changes in strategies to evaluate the overall toxicity of chemicals as well as their carcinogenic potential....Full Text Available

1990-06-01

434

An examination of the ignition delay period in gas-fueled diesel engines  

Energy Technology Data Exchange (ETDEWEB)

Changes in the physical and chemical processes during the ignition delay period of a gas-fueled diesel engine (dual-fuel engine) due to the increased admission of the gaseous fuels and diluents are examined. The extension to the chemical aspects of the ignition delay with the added gaseous fuels and the diluents into the cylinder charge is evaluated using detailed reaction kinetics for the oxidation of dual-fuel mixtures at an adiabatic constant volume process while employing n-heptane as a representative of the main components of the diesel fuel. In the examination of the physical aspects of the delay period, the relative contributions of changes in charge temperature, pressure, physical properties, pre-ignition energy release, heat transfer, and the residual gas effects due to the admission of the gaseous fuels are discussed and evaluated. It is shown that the introduction of gaseous fuels and diluents into the diesel engine can substantially ...

1998-01-01

435

Amyloid Oligomer Neurotoxicity, Calcium Dysregulation, and Lipid Rafts  

UK PubMed Central (United Kingdom)

Amyloid proteins constitute a chemically heterogeneous group of proteins, which share some biophysical and biological characteristics, the principal of which are the high propensity to acquire an incorrect...Full Text Available

436

Air pollution induces heritable DNA mutations  

UK PubMed Central (United Kingdom)

Hundreds of thousands of people worldwide live or work in close proximity to steel mills. Integrated steel production generates chemical pollution containing compounds that can induce genetic damage...Full Text Available

2002-12-10

437

A thermodynamic analysis of alternative approaches to chemical looping combustion  

Energy Technology Data Exchange (ETDEWEB)

In this article, we review and clarify some of the points made by previous authors regarding chemical looping combustion (CLC). While much of the recent interest in chemical looping combustion has been associated with carbon sequestration, our primary interest here is its potential to increase the thermodynamic efficiency of converting fuel chemical energy into useful work. We expand on several points about the details of CLC that we feel have not previously been sufficiently explored, and suggest alternative (and possibly more practical) approaches that exploit some of the same thermodynamic concepts. We illustrate our key points with {First} and {Second} Law analyses of ideal conceptual processes, which in addition to {CLC} also include isothermal, non-equilibrium, preheated combustion and combustion with thermochemical recuperation. Our results suggest that a significant portion of the potential efficiency benefit of CLC ...

2011-01-01

438

A piggyBac transposon-based genome-wide library of insertionally mutated Blm-deficient murine ES cells  

UK PubMed Central (United Kingdom)

Cultured mouse or human embryonic stem (ES) cells provide access to all of the genes required to elaborate the fundamental components and physiological systems of a mammalian cell. Chemical or insertional...Full Text Available

2009-04-01

439

A novel gas turbine cycle with hydrogen-fueled chemical-looping combustion  

Energy Technology Data Exchange (ETDEWEB)

In this paper we have proposed a novel gas turbine cycle with hydrogen-fueled chemical-looping combustion, and the system study on two hydrogen-fueled power plants, the new gas turbine cycle and an advanced gas turbine cycle with H{sub 2}/O{sub 2} combustion, has been investigated with the aid of exergy principle (EUD methodology). The hydrogen fueled chemical-looping combustion in the new gas turbine cycle consists of two successive reactions: hydrogen fuel is reacted with metal oxide (reduction of metal oxide), and then instead of air or pure oxygen, the reduced metal is successively oxidized by the saturated air. As a result, the new hydrogen-fueled gas turbine cycle has a breakthrough performance, with at least about 12 percentage-point higher efficiency compared to the gas turbine cycle with H{sub 2}/O{sub 2} combustion, and will be environmentally superior due to complete elimination of NO{sub x} formation. The promising results obtained ...

2000-12-01

440

A generalized Fisher equation and its utility in chemical kinetics  

UK PubMed Central (United Kingdom)

A generalized Fisher equation (GFE) relates the time derivative of the average of the intrinsic rate of growth to its variance. The GFE is an exact mathematical result that has been widely used in population...Full Text Available

2010-07-20

441

A chemical-modification approach to the olfactory code. Studies with a thiol-specific reagent  

UK PubMed Central (United Kingdom)

The effects of thiol-specific reagents on the amplitude of the electro-olfactogram (E.O.G.) responses elicited from frog olfactory mucosa by pulses of odorant vapours was studied. The impermeant thiol-specific...Full Text Available

1978-12-15

442

A Combination of Dual-mode 2,940 nm Er:YAG Laser Ablation with Surgical Excision for Treating Medium-sized Congenital Melanocytic Nevus  

UK PubMed Central (United Kingdom)

BackgroundThere are various treatment options for congenital melanocytic nevus (CMN), including surgical excision, dermabrasions, curettage, laser treatment, chemical peels and cryosurgery....Full Text Available

2009-05-01

443

8. Application of radionuclide X-ray fluorescence analysis in other fields of science and technology  

International Nuclear Information System (INIS)

Certain applications are described of radionuclide X-ray fluorescence analysis in the ore dressing industry, in the manufacture of building materials, in metallurgy, pharmacy, in the chemical, photographic and paper industries, in space exploration, in archeology and for measuring the thicknesses of thin layers of coatings. (ES).

1983-12-01

444

13th Meeting of the Scientific Group on Methodologies for the Safety Evaluation of Chemicals (SGOMSEC): alternative testing methodologies for organ toxicity.  

UK PubMed Central (United Kingdom)

In the past decade in vitro tests have been developed that represent a range of anatomic structure from perfused whole organs to subcellular fractions. To assess the use of in vitro tests for toxicity...Full Text Available

1998-04-01

445

13C-NMR Assessment of the Pattern of Organic Matter Transformation during Domestic Wastewater Treatment by Autothermal Aerobic Digestion (ATAD)  

UK PubMed Central (United Kingdom)

The pattern of biodegradation and the chemical changes occurring in the macromolecular fraction of domestic sludge during autothermal thermophilic aerobic digestion (ATAD) was monitored and characterised...Full Text Available

2009-08-01

446

The use of x-ray fluorescence in the detection of inorganic elements in medicines drugs  

International Nuclear Information System (INIS)

Based on the instrumental wavelength dispersive X-ray fluorescence technique of analysis (W D-X R F), the inorganic elements in four samples of commercial medicines drugs were analyzed. The samples were used without any chemical separation of the elements or chemical pre-treatment. Eleven elements could be identified, namely Si, P, S, Cl, K, Ca, Ti, Mn, Fe, Cu and Zn. However, Si, Ti and Mn have not been mentioned in the printed instructions for the use of the medicines drugs by the producers. (author)

447

The use of lead isotopic abundances in trace uranium samples for nuclear forensics analysis  

International Nuclear Information System (INIS)

Secondary ion mass spectrometry (SIMS), secondary electron microscopy (SEM) and X-ray analysis have been applied to the measurement of U-bearing particles with the intent of gleaning information concerning their history and/or origin. The lead isotopic abundances are definitive indicators that U-bearing particles have come from an ore-body, even if they have undergone chemical processing. SEM images and X-ray analysis can add further information to the study that may allude to the extent of chemical processing. The presence of 'common' lead that does not exhibit a radiogenic signature is clear evidence of anthropogenic origin. (author)

2010-06-01

448

Technical report for fabrication and performance test of electrochemical/spectroscopic measurement system  

International Nuclear Information System (INIS)

Development of evaluation technology of electrochemical reactions is very essential to understand chemical behavior of actinides and lanthanides in molten salt media in relation to the development of Pyrochemical process. The on-line electrochemical/spectroscopic measurement system is to produce electrochemical parameters and thermodynamic parameters of actinides and lanthanides in molten salts by using spectroscopic techniques such as UV-VIS absorption as well as electrochemical in-situ measurement techniques. The on-line electrochemical/spectroscopic measurement system can be applied to understand the chemical reactions and oxidation states of actinides and lanthanides in molten salts eventually for the Pyrochemical process

2006-09-01

449

Technical area status report for chemical/physical treatment. Volume 2, Appendices  

Energy Technology Data Exchange (ETDEWEB)

These Appendices describe various technologies that may be applicable to the Mixed Waste Treatment Plant (MWTP) Chemical/Physical Treatment System (CPTS). These technologies were identified by the CPTS Technical Support Group (TSG) as potentially applicable to a variety of separation, volume reduction, and decontamination requirements. The purpose was to identify all available and developing technologies, and their characteristics, for subsequent evaluation for specific requirements identified for the CPTS. However, the technologies described herein are not necessarily all inclusive, nor are they necessarily all applicable.

1993-08-01

450

Synthesis and characterization of Rosebengal/folicacid-functionalized multiwall carbon nanotubes  

British Library Electronic Table of Contents (United Kingdom)

Multiwall carbon nanotubes (MWCNTs) were functionalized with a photosensitizer, rosebengal (RB), and folicacid (FA), an anti-cancer drug simultaneously and individually, which was characterized with various analytical instruments like Fourier Transform Iinfrared (FTIR) spectroscopy, UV?Vis spectroscopy, Thermogravimetric analysis (TGA), Photoluminescence (PL) spectroscopy, X-ray photoelectron spectroscopy (XPS), and Transmission electron microscopy (TEM). FTIR spectra confirmed the chemical modification of MWCNT. The chemical functionalization of MWCNT with RB was further supported by UV?Vis and PL spectra.

2011-01-01

451

Structure, reactivity, and biological properties of hidantoines; Estrutura, reatividade e propriedades biologicas de hidantoinas  

Energy Technology Data Exchange (ETDEWEB)

Hydantoin (imidazolidine-2,4-dione) is a 2,4-diketotetrahydroimidazole discovered by Baeyer in 1861. Thiohydantoins and derivatives were prepared, having chemical properties similar to the corresponding carbonyl compounds. Some biological activities (antimicrobial, anticonvulsant, schistosomicidal) are attributed to the chemical reactivity and consequent affinity of hydantoinic rings towards biomacromolecules. Therefore, knowledge about the chemistry of hydantoins has increased enormously. In this review, we present important aspects such as reactivity of hydantoins, acidity of hydantoins, spectroscopy and crystallographic properties, and biological activities of hydantoin and its derivatives. (author)

2008-07-01

452

Structural, Vibrational and Mechanical Studies of Hydroxyapatite produced by wet-chemical methods  

CERN Document Server

Hydroxyapatite samples were produced by two different wet-chemical methods, and characterized by x-ray diffraction, infrared and compression strength measurements. The x-ray diffraction measurements were simulated using the Rietveld method, and structural data as lattice parameters and average crystallite size were obtained. The infrared spectra showed the presence of CO$_3^{2-}$ ions in all samples, indicating a contamination by these ions. By mixing samples produced by both methods, a bioceramic was obtained and, after sintering, samples with very high compression strengths (26--30 MPa) were obtained.

2004-01-01

453

Radiation-induced chemical modification of wood  

International Nuclear Information System (INIS)

The results of theoretical and experimental investigations, describing the effect of ionizing radiation on wood and its main components and methods for production of wood-plastic composites by means of radiation-induced chemical modification are generalized. Domestic and foreign experience in their production is systematized; physico-mechanical characteristics of new material, simulation and calculation of irradiating devices, as well as calculation and experimental study of #gamma#-radiation attenuation both by wood material and by wood of different species are given. Gamma sources ("6"0Co isotope, a hot loop of a nuclear reactor) as well as electron accelerators are considered as ionizing radiation sources.

1985-01-01

454

Oil shale oxidation at subretorting temperatures  

Energy Technology Data Exchange (ETDEWEB)

Green River oil shale was air oxidized at subretorting temperatures. Off gases consisting of nitrogen, oxygen, carbon monoxide, carbon dioxide, and water were monitored and quantitatively determined. A mathematical model of the oxidation reactions based on a shrinking core model has been developed. This model incorporates the chemical reaction of oxygen and the organic material in the oil shale as well as the diffusivity of the oxygen into the shale particle. Diffusivity appears to be rate limiting for the oxidation. Arrhenius type equations, which include a term for oil shale grade, have been derived for both the chemical reaction and the diffusivity.

1980-06-01

455

Nonequilibrium detonation of composite explosives  

Energy Technology Data Exchange (ETDEWEB)

The effect of nonequilibrium diffusional flow on detonation velocities in composite explosives is examined. Detonation conditions are derived for complete equilibrium, temperature and pressure equilibrium, and two forms of pressure equilibrium. Partial equilibria are associated with systems which have not had sufficient time for transport to smooth out the gradients between spatially separate regions. The nonequilibrium detonation conditions are implemented in the CHEQ equation of state code. We show that the detonation velocity decreases as the non-chemical degrees of freedom of the explosive are allowed to equilibrate. It is only when the chemical degrees of freedom are allowed to equilibrate that the detonation velocity increases. {copyright} {ital 1998 American Institute of Physics.}

1998-07-01

456

Non-thermal plasma destruction of allyl alcohol in waste gas: kinetics and modelling  

International Nuclear Information System (INIS)

Non-thermal plasma treatment is a promising technique for the destruction of volatile organic compounds in waste gas. A relatively unexplored technique is the atmospheric negative dc multi-pin-to-plate glow discharge. This paper reports experimental results of allyl alcohol degradation and ozone production in this type of plasma. A new model was developed to describe these processes quantitatively. The model contains a detailed chemical degradation scheme, and describes the physics of the plasma by assuming that the fraction of electrons that takes part in chemical reactions is an exponential function of the reduced field. The model captured the experimental kinetic data to less than 2 ppm standard deviation.

2008-02-01

457

New methods of production of titanium alloy ingots  

International Nuclear Information System (INIS)

Production of titanium alloys from the mixture containing large amounts of metallurgy wastes is very promising. It is shown that unlimited possibilities of the waste material use in the mixture (up to 100%) are provided by garnissage melting, the size of the cast being limited only by that of the vessel. With garnissage being used as a consumed electrode the metal is refined from hydrogen and the blank ingots to serve as consumed electrodes in electro-slag remelting are chemically homogeneous. The ingots thus obtained have dense structure, rather fine grain homogeneous chemical composition, are no less pure than those obtained by vacuum arc remelting and provide for economic savings.

458

Initiation transient in dilute explosives  

Energy Technology Data Exchange (ETDEWEB)

In the context of the shock-initiation problem, we study analytically the first effects of chemistry, treating a small chemical heat release as a perturbation on an inert flow. Specifically, we study the initial transient in plane-shock initiation in a dilute explosive, where the chemical energy is small relative to the mechanical-thermal energy. The vehicle for the study is the mathematical analog for reactive flow. The solution resembles a double refraction: to first order, the pressure or density is a superposition of two forward-going waves, both originating at the rear boundary, and carrying the same function, but running at different velocities. Surprisingly, this first-order solution is independent of the sensitivity of the reaction rate to the state, which appears only at second order.

1981-01-01

459

Influence of the reductive preparation conditions on the morphology and on the electrochemical performance of Sn/SnSb  

Energy Technology Data Exchange (ETDEWEB)

Lithium storage metals and alloys can be suitable high-capacity anode materials for lithium-ion batteries, when the morphology is specifically designed. Here, we compare three different Sn/SnSb multiphase anode materials in powder form, which have been prepared in aqueous and organic solution by chemical precipitation using NaBH{sub 4} or Zn as reductive agents. The obtained morphologies, chemical compositions, and the electrochemical performance will be comparatively discussed. The variety of synthesis parameters which have an effect on the morphology of the obtained anode materials will be particularly highlighted.

2004-03-15

460

Hazardous waste operational plan for site 300  

Energy Technology Data Exchange (ETDEWEB)

This plan outlines the procedures and operations used at LLNL's Site 300 for the management of the hazardous waste generated. This waste consists primarily of depleted uranium (a by-product of U-235 enrichment), beryllium, small quantities of analytical chemicals, industrial type waste such as solvents, cleaning acids, photographic chemicals, etc., and explosives. This plan details the operations generating this waste, the proper handling of this material and the procedures used to treat or dispose of the hazardous waste. A considerable amount of information found in this plan was extracted from the Site 300 Safety and Operational Manual written by Site 300 Facility personnel and the Hazards Control Department.

1982-02-12

461

Getter pumping  

CERN Document Server

A surface may provide a useful pumping action when able to retain adsorbed gas molecules for the duration of a given experiment. To fulfil this condition at room temperature, strong binding forces, as those resulting from chemical reactions, are required. Materials able to react with gases to form stable chemical compounds are called getters. The two main families of getters (evaporable and non-evaporable, or NEG) are presented and discussed. Special emphasis is placed on the NEG strips currently used for the vacuum systems of particle accelerators, and on the newly developed NEG thin-film coatings, in view of their possible future applications.

2007-01-01

462

Electron Beam and Gamma Radiolysis of Solid-State Metoclopramide  

British Library Electronic Table of Contents (United Kingdom)

Purpose Study the radiolysis of solid-state metoclopramide hydrochloride at various absorbed doses. Elucidate the structure of the degradation products to gain information on the radiolysis mechanisms. Methods Solid-state metoclopramide samples were irradiated at several doses with gamma rays and high-energy electrons to evaluate the influence of the dose rate. High-performance liquid chromatography with a diode array detector was used to measure the chemical potency as a function of the absorbed dose and to quantify the degradation products. The characterization of degradation products was performed by liquid chromatography/atmospheric pressure chemical ionization/tandem mass spectrometry. Results The degradation of solid-state metoclopramide after irradiation was negligible. No qualitati...

2006-01-01

463

Detailed kinetic modeling of autoignition chemistry  

Energy Technology Data Exchange (ETDEWEB)

The development of detailed chemical kinetic reaction mechanisms for analysis of autoignition and knocking of hydrocarbon fuels is described. In particular, kinetic processes of concern for the oxidation of complex hydrocarbon fuel molecules are emphasized. The wide ranges of temperature and pressure which are encountered by end gases in automobile engine combustion chambers result in extreme demands on reaction mechanisms which are intended to describe knocking conditions and predict rates of combustion and ignition. The reactions and chemical species which are most important in each temperature and pressure regime are discussed, and the validation of these reaction mechanisms through comparison with idealized experimental results is described. 53 refs., 8 figs., 5 tabs.

1987-07-22

464

Decontamination of the chemical warfare agent simulant dimethyl methylphosphonate by means of large-area low-temperature atmospheric pressure plasma  

British Library Electronic Table of Contents (United Kingdom)

Dimethyl methylphosphonate (DMMP), a chemical simulant of the nerve gas GB, was decontaminated with a nonthermal atmospheric pressure plasma. The decontamination efficiency was measured qualitatively by means of Fourier transform spectroscopy and quantitatively by means of gas chromatography. With helium gas only, 10g/m2 of DMMP on an aluminum surface was 99.9% decontaminated in 2min, furthermore, with the addition of 5% of oxygen gas, it was 99.99% decontaminated in 10min. Given the low input power (<100W) and temperature (<75degreeC), this plasma is eligible for nondestructive decontamination of almost all material surfaces.

2009-01-01

465

Corrosion 2003. Conference papers on CD-ROM  

Energy Technology Data Exchange (ETDEWEB)

Papers are presented under 38 symposia. Subjects included reinforced concrete, protective coatings and linings, cathodic/anodic protection, chemical cleaning of boilers, managing corrosion with plastics, water treatment, HRSG boiler tube failure analysis, corrosion in oil and gas production, corrosion in petroleum refining and gas, processing, pipelines and tanks, high temperature materials, chemical process industry, aerospace equipment, materials technology developments for incinerators and waste fuel-fired processors, materials and corrosion in fossil-fuels conversion and combustion, corrosion in nuclear systems, marine corrosion, building systems, corrosion mechanisms, corrosion inhibitors and corrosion monitoring and measurement.

2003-07-01

466

Composition of insoluble kerogen-like organic polymer in the carbonate rocks of Orenburg gas-condensate deposit  

British Library Electronic Table of Contents (United Kingdom)

The concentrates of scattered organic matter???kerogen-like polymer, which is insoluble in acids and organic solvents???were isolated from rock samples taken at different depths from various stratigraphic units at the productive deposits of the Orenburg oil-gas condensate field using chemical methods. The chemical composition of the kerogen-like polymer and the concentrations of trace elements in it were studied. The regularities of evolutionary changes in the composition of the organic matter and the concentrations of trace elements in it in the order of the kerogen-like polymer and the following its consecutive derivatives were established: asphaltenes, ethanol-benzene tars, benzene tars, oils, and paraffins

2011-01-01

467

Combining laser chemical processing and aerosol jet printing: a laboratory scale feasibility study  

British Library Electronic Table of Contents (United Kingdom)

Abstract First results showing the viability of combining laser chemical processing (LCP) and aerosol jet printing (AJP) technologies to produce a high-efficiency front side for silicon solar cells are presented. LCP simultaneously opens the anti-reflection coating (ARC) and highly dopes the underlying silicon to create a selective emitter, while AJP is the first in a two-step fine-line contact formation procedure. The electrical properties as well as the morphology of the resulting structures are presented. Performance similar to that achieved with evaporated TiPdAg metallization is demonstrated. Copyright 2010 John Wiley & Sons, Ltd.

2011-01-01

468

Chemical reactions in a solar furnace 2: Direct heating of a vertical reactor in an insulated receiver. Experiments and computer simulations  

Energy Technology Data Exchange (ETDEWEB)

The performance of a solar chemical heat pipe was studied using CO{sub 2}reforming of methane as the endothermic reaction. A directly heated vertical reactor, packed with a rhodium catalyst was used. The solar tests were carried out in the Schaeffer solar furnace of the Weizmann Institute of Science. The power absorbed was up to 6.3 KW, the maximal flow rates of the gases reached 11,000 1/h, and the methane conversions reached 85%. A computer model was developed to simulate the process. Agreement of the calculations with the experimental results was quite satisfactory.

1992-01-01

469

Chemical reaction effects on unsteady MHD flow past semi-infinite vertical porous plate with viscous dissipation  

British Library Electronic Table of Contents (United Kingdom)

The chemical reaction effect on an unsteady magnetohydrodynamic (MHD) flow past a semi-infinite vertical porous plate with viscous dissipation is analyzed. The governing equations of motion, energy, and species are transformed into ordinary differential equations (ODEs) using the time dependent similarity parameter. The resultant ODEs are then solved numerically by a finite element method. The effects of various parameters on the velocity, temperature, and concentration profiles are presented graphically, and the values of the skin-friction, Nusselt number, and Sherwood number for various values of physical parameters are presented through tables.

2011-01-01

470

Chemical decontamination methods for coatings  

Energy Technology Data Exchange (ETDEWEB)

A review of chemical decontamination methods for coatings indicates the following: the ease of both contamination and decontamination is a function of the radionuclide and the pH of the environment; the coating type is important in determining whether the contamination is loosely adsorbed, complexed, or contained in porous filler material; the condition of the coating is important to the decontamination factor obtained. Thus coatings can be decontaminated provided the solvent is sufficiently acid to solubilize the radionuclide and the complexant strength of the solvent is greater than that of the coating. Difficulties arise if the contamination is associated with fillers. Furthermore, though nothing has been said about temperature, decontamination of metal goes faster and, usually, with better efficiency at high temperatures. 11 references, 3 figures.

1984-05-01

471

Chemical constituents of Galianthe brasiliensis (Spreng.) E.L.Cabral and Bacigalupo (Rubiaceae)  

International Nuclear Information System (INIS)

This paper describes the chemical constituents isolated from aerial parts of the plant Galianthe brasiliensis. From a methanol extract, the iridoid glycosides asperuloside, deacetylasperuloside, mixture of Z- and E-6-O-p-coumaroylscandoside methyl ester, the triterpene ursolic acid and the steroids stigmasterol, campesterol, b-sitosterol and 3-O-b-glucopyranosyl sitosterol were isolated. The structures of the natural products were identified on the basis of spectral data, including 2D NMR experiments. The antiproliferative properties of the crude methanolic extract were investigated against a series of nine human cancer cell lines. (author)

472

Chemical and Process - EA BOOKS  

Wastenet

... Focuses on distillation and packed towers, and presents the methods and fundamentals of plant design along with supplemental mechanical and related data, nomographs, data charts and heuristics. AU$223.45 ex-GST Terms and Conditions Microchemical Engineer... Provides the information chemists and engineers need to evaluate the use of microreactors, covering the technical, operational, and economic considerations for various applications. AU$136.36 ex-GST Terms and Conditions Perry's Chemical Engin... Was: $199.95 inc gst NOW: $129.95 Special Price ...

473

Chemical and Process - EA BOOKS  

Wastenet

... Focuses on distillation and packed towers, and presents the methods and fundamentals of plant design along with supplemental mechanical and related data, nomographs, data charts and heuristics. AU$223.45 ex-GST Terms and Conditions CRC Handbook of Chemis... For almost a century this handbook has been updated annually, except for a few wartime years, and has served generations of engineers and scientists. Current daily price AU$209.09 ex-GST Terms and Conditions Perry's Chemical Engin... Was: $199.95 inc gst NOW: ...

474

Certified Reference Materials (CRM) for the quality control of metals chemical forms determinations in environment, in support to the European Union legislation; Materiaux de reference certifies pour le controle de qualite des determinations de formes chimiques des metaux dans l`environnement, en soutien a la legislation de l`Union Europeenne  

Energy Technology Data Exchange (ETDEWEB)

This work gives a global view of legislations in which are included metals chemical states, briefly recalls the conditions to be respected for the CRM (Certified Reference Materials), and describes the results of some current plans for the Norms, Measures and Tests program. (O.M.) 23 refs.

1997-03-01

475

Ceramic Materials : Physics 130 : Properties of Matter  

Science.gov (United States)

Lecture notes (pdf) on Ceramics is part of a physics course on the properties of matter from the University of Auckland, Department of Chemical and Materials Engineering. The following topics are covered: types of chemical bonding, degree of ionic character, structure of ceramics and crystallography, interstitial sites in different crystal structures, silicate structures, glasses, glass transition temperature, glass viscosity, thermal and mechanical properties of ceramics and glasses, fracture properties of ceramics and processing of ceramic materials. Keywords: ionic bonds; covalent bonds; coordination numbers; thermal shock; grain growth; sintering; green body

2007-02-01

476

Analysis of the chemical transformations induced at the surface of polyacrylonitrile and polymethacrylonitrile films by 5 keV proton beams  

Energy Technology Data Exchange (ETDEWEB)

In this work, the chemical transformations induced by 5 keV protons (10{sup 6} ion cm{sup -2}) at the surface of 0.4 {mu}m polyacrylonitrile and polymethacrylonitrile films are analysed by XPS and IRRAS. Spectroscopic changes in both the polymers are globally similar, the most significant feature being a lower relative concentration of nitrogen with respect to carbon closer to the surface. Quantitatively, this change is more marked in the case of polyacrylonitrile which suggests a direct relation with the hydrogen in {alpha} to the nitrile function.

1999-05-02

477

Trans-generational radiation-induced chromosomal instability in the female enhances the action of chemical mutagens  

Energy Technology Data Exchange (ETDEWEB)

Genomic instability can be produced by ionising radiation, so-called radiation-induced genomic instability, and chemical mutagens. Radiation-induced genomic instability occurs in both germinal and somatic cells and also in the offspring of irradiated individuals, and it is characterised by genetic changes including chromosomal rearrangements. The majority of studies of trans-generational, radiation-induced genomic instability have been described in the male germ line, whereas the authors who have chosen the female as a model are scarce. The aim of this work is to find out the radiation-induced effects in the foetal offspring of X-ray-treated female rats and, at the same time, the possible impact of this radiation-induced genomic instability on the action of a chemical mutagen. In order to achieve both goals, the quantity and quality of chromosomal damage were analysed. In order to detect trans-generational genomic instability, a total of 4806 ...

2008-04-02

478

Responses to comments on the remedial investigation/feasibility study-environmental impact statement for remedial action at the Chemical Plant area of the Weldon Spring site (November 1992)  

Energy Technology Data Exchange (ETDEWEB)

The US Department of Energy (DOE) is responsible for cleanup activities at the Weldon Spring site in St. Charles County, Missouri. The site consists of a chemical plant area and a noncontiguous limestone quarry; both areas are radioactively and chemically contaminated as a result of past processing and disposal activities. Explosives were produced by the US Army at the chemical plant in the 1940s, and uranium and thorium materials were processed by DOE`s predecessor agency in the 1950s and 1960s. During that time, various wastes were disposed of at both areas of the site. The DOE is conducting cleanup activities at the site under its Environmental Restoration and Waste Management Program. The integrated remedial investigation/feasibility study-environmental impact statement (RI/FS-EIS) documents for the chemical plant area were issued to the public in November 1992 as the draft RI/FS-EIS. (The CERCLA ...

1993-06-01

479

Quarterly progress report for the Chemical and Energy Research Section of the Chemical Technology Division: October-December 1997  

Energy Technology Data Exchange (ETDEWEB)

This report summarizes the major activities conducted in the Chemical and Energy Research Section of the Chemical Technology Division at Oak Ridge National Laboratory (ORNL) during the period October--December 1997. The 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 six major areas of research: Hot Cell Operations, Process Chemistry and Thermodynamics, Separations and Materials Synthesis, Fluid Structure and Properties, Biotechnology Research, and Molecular Studies. The name of a technical contact is included with each task described, and readers are encouraged to contact these individuals if they need additional information. Activities conducted within the ...

1999-02-01

480

Physical basis of the effect of hemoglobin on the "3"1P NMR chemical shifts of various phosphoryl compounds  

International Nuclear Information System (INIS)

The marked difference between the intra- and extracellular "3"1P NMR chemical shifts of various phosphoryl compounds when added to a red cell suspension may be largely understood in terms of the effects of hemoglobin on the "3"1P NMR chemical shifts. The presence of [oxy- or (carbonmonoxy)-] hemoglobin inside the red cell causes the bulk magnetic susceptibility of the cell cytoplasm to be significantly less than that of the external solution. This difference is sufficient to account for the difference in the intra- and extracellular chemical shifts of the two phosphate esters trimethyl phosphate and triethyl phosphate. However, in the case of the compounds dimethyl methylphosphonate, diethyl methylphosphonate, and trimethylphosphine oxide as well as the hypophosphite, phenylphosphinate, and diphenylphosphinate ions, hemoglobin exerts an additional, much larger, effect, causing the "3"1P NMR resonances to shift to lower ...

481

Energy Conversion and Storage Program: 1992 Annual report  

Energy Technology Data Exchange (ETDEWEB)

This report is the 1992 annual progress report for the Energy Conversion and Storage Program, a part of the Energy and Environment Division of the Lawrence Berkeley Laboratory. Work described falls into three broad areas: electrochemistry; chemical applications; and materials applications. The Energy Conversion and Storage Program applies principles of chemistry and materials science to solve problems in several areas: (1) production of new synthetic fuels, (2) development of high-performance rechargeable batteries and fuel cells, (3) development of advanced thermochemical processes for energy conversion, (4) characterization of complex chemical processes and chemical species, and (5) study and application of novel materials for energy conversion and transmission. Projects focus on transport-process principles, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, ...

1993-06-01

482

Chemistry of transuranium elements and compounds  

International Nuclear Information System (INIS)

Studies are made in this program to enhance our understanding of the role of 5f electrons in chemical bonding. Most of our studies on the macroscopic scale emphasize certain isotopes available from the National Transplutonium Production Program centered at HFIR/TRU -namely, _9_6"2"4"8Cm, _9_7"2"4"9Bk, _9_8"2"4"9Cf, _9_9"2"5"3Es, and _9_9"2"5"4Es. Particular classes of compounds, such as hydrides, chalcogenides, and pnictides are often selected for study on the basis of their utility in bringing out significant chemical differences between the lanthanides and the actinides. High temperature/high pressure experiments on actinide metals and compounds reveal characteristics about the degree of 5f electron localization as a function of atomic number in the series. Magnetic properties of metals and compounds are investigated using ultra-sensitive methods and hydration numbers of ions in solution are investigated by neutron scattering at HFIR. As a ...

1986-05-01

483

Changes in soil N fractions and utilization of recently immobilized fertilizer N by wheat as influenced by application of some organic chemicals in rice-wheat sequence  

International Nuclear Information System (INIS)

Effect of two organic chemicals viz., 2,4-dinitrophenyl hydrazone (C_1) and naphthyl ethylene diamine (C_2) was studied by their application alone and together (Csub(1+2) at the rate of 10 ppm by growing wheat on a loamy soil (Typic ustochrept) containing recently immobilized fertilizes N of "1"5N - urea applied at 60, 120 and 180 ppm N to preceding rice under greenhouse conditions of a rice-wheat sequence. The application of C_1 and C_2 alone; and their combined application (Csub(1+2) produced 12, 15 and 18 per cent higher wheat grain yield over no-chemical application i.e. Co (3.50 g/pot). The chemicals also showed their beneficial effect on utilization of recently immobilized fertilizer N, as was evidenced by significantly higher "1"5N recovery values in wheat with C_1, C_2 and Csub(1+2)(2.84, 3.63 and 3.54 per cent, respectively) than that of Co (2.29 per cent). The soil N fractions were affected by ...

484

Biological and Chemical Security  

Science.gov (United States)

The LLNL Chemical & Biological National Security Program (CBNP) provides science, technology and integrated systems for chemical and biological security. Our approach is to develop and field advanced strategies that dramatically improve the nation's capabilities to prevent, prepare for, detect, and respond to terrorist use of chemical or biological weapons. Recent events show the importance of civilian defense against terrorism. The 1995 nerve gas attack in Tokyo's subway served to catalyze and focus the early LLNL program on civilian counter terrorism. In the same year, LLNL began CBNP using Laboratory-Directed R&D investments and a focus on biodetection. The Nunn-Lugar-Domenici Defense Against Weapons of Mass Destruction Act, passed in 1996, initiated a number of U.S. nonproliferation and counter-terrorism programs including the DOE (now NNSA) Chemical and Biological ...

2002-12-19

485

Modeling global atmospheric CO2 with improved emission inventories and CO2 production from the oxidation of other carbon species  

Energy Technology Data Exchange (ETDEWEB)

The use of global three-dimensional (3-D) models with satellite observations of CO2 in inverse modeling studies is an area of growing importance for understanding Earth s carbon cycle. Here we use the GEOS-Chem model (version 8-02-01) CO2 mode with multiple modifications in order to assess their impact on CO2 forward simulations. Modifications include CO2 surface emissions from shipping (0.19 PgC yr 1), 3-D spatially-distributed emissions from aviation (0.16 PgC yr 1), and 3-D chemical production of CO2 (1.05 PgC yr 1). Although CO2 chemical production from the oxidation of CO, CH4 and other carbon gases is recognized as an important contribution to global CO2, it is typically accounted for by conversion from its precursors at the surface rather than in the free troposphere. We base our model 3-D spatial distribution of CO2 chemical production on monthly-averaged loss rates of CO (a key precursor and intermediate in the ...

2010-01-01

486

Characterisation of thin films on rough steel substrates by FTIR microscopy and imaging  

International Nuclear Information System (INIS)

Complete text of publication follows. According to the new European regulations (Restrictions of Hazardous Substance Directive), there is an emerging demand for environmental friendly metal treatments instead on formerly used chromate conversion coating technique. The aim of the present investigations was to characterise and compare silicon containing protective thin layers on roughened galvanized steel surfaces (with average roughness of 0.7 microns), using FTIR microscopy and imaging techniques. The silicon containing coatings were produced either by Chemical Vapour Deposition (CVD) or by wet chemical treatment using liquid silane. FTIR techniques offer new possibilities in the characterisations and chemical mapping of differently coated thin films, besides SEM+EDS, AFM, nanoindentation, XPS measurements (P. Nemeth et al., Materials Science Forum, 589 (2008) 433-438). All measurements were carried out by a Varian FTS-7000 ...

487

Utilization of recently immobilized fertilizer nitrogen by wheat as influenced by some organic chemicals in a rice-wheat sequence  

International Nuclear Information System (INIS)

The effectiveness of two organic chemicals, viz. 2, 4-dinitrophenyl hydrazone and naphthyl ethylene diamine applied at the rate of 10 mg kg"-"1 soil to wheat were studied as mobilizers of recently immobilized fertilizer N applied ("1"5N urea) at the rate of 60, 120 and 180 mg kg"-"1 soil to rice under greenhouse condition on a Typic Ustochrept. Rice as a first crop gave "1"5N recovery ranging from 35 to 37 per cent and more than one third of the applied fertilizer N was retained in the soil. Chemicals provided significantly higher mineral N during the initial growth period of wheat grown as a subsequent crop on the soil having different levels of residual nitrogen. "1'5N removal by plants at all the growth stages was significantly higher due to chemicals. The chemicals also showed significant effect in increasing the grain yield which caused higher N uptake and showed "1"5N recovery escalation. The ...

488

Titania-supported iron oxide as oxygen carrier for chemical-looping combustion of methane  

Energy Technology Data Exchange (ETDEWEB)

Chemical-looping combustion is a two-stage process proposed as an alternative for the combustion of carbonaceous materials, such as natural gas or coal gas, for almost complete CO{sub 2} capture. In the reduction stage, the structural oxygen contained in the lattice of a reducible inorganic oxide, is used for combustion of the carbonaceous material. In the regeneration stage the oxygen carrier, found in a reduced state after the reduction stage, is regenerated with pure air to recover the physical and chemical properties of the carrier, ready to reinitiate a new cycle reduction-regeneration. In a typical multicycle reactor test, the carriers are subjected to accumulative chemical and thermal stresses and the performance will, probably, decay progressively with the number of cycles. The occurrence of some side reactions may limit the efficiency of the overall process in CO{sub 2} capture. In this paper, titania-supported ...

2007-01-15

489

Natural gas in Lake Erie: a reconnaissance survey of discharges from an offshore drilling rig  

Energy Technology Data Exchange (ETDEWEB)

Field studies were conducted May 28-June 1, 1979, to determine the chemical composition and physical behavior of discharges from an offshore gas drilling rig in the central basin of Lake Erie. The drilling operation was observed for four days, from rig jackup to the circulation of mud through the borehole after drilling had been completed. Resuspension studies using nephelometry, supplemented with chemical analyses, indicated little resuspension of lake bottom materials or release of metals to the water column during rig jack-up. Portions of the turbidity plumes generated during drilling were buoyant. Three surface turbidity plumes were mapped with nephelometry to a point at which particulate concentrations reached background levels in the Lake. Detectable plumes were approx. 400 to 1500 m in length and had maximum widths < 230 m. A chemical survey conducted in the plume during early gas shows indicated that discharged ...

1980-10-01

490

Making porous membranes by chemical etching of heavy-ion tracks in {beta}-PVDF films  

Energy Technology Data Exchange (ETDEWEB)

Production of porous membranes using heavy ion bombardment and subsequent chemical etching of poly(vinylidene difluoride) (PVDF) films has been reported several years ago. However, porous membranes with pore diameter in the nanometer scale requires a better understanding of the chemical etching mechanism. In this work PVDF foils irradiated with Sn ions (2.85 MeV per nucleon) were exposed to several etching conditions which involved permanganate oxidation in different alkaline environments. The solution of KOH 9 mol L{sup -1} and saturated in KMnO{sub 4} was the best etching reactant for PVDF. Functional groups created in the alkaline and oxidative attack by permanganate were studied by FT-IR and UV-vis spectroscopy. The spectroscopic data reveals that the formation of pores occurs by a two-step mechanism: (i) double bonds as a result of dehydrofluorination induced by alkaline media and (ii) oxidation of these double bonds in permanganate ...

2005-07-01

491

Effects of ions and electrons on atmospheric lifetimes of fully fluorinated compounds  

International Nuclear Information System (INIS)

Fully fluorinated compounds (perfluoro compounds) represent a class of chemicals which include many extremely inert species-inert to both chemical reaction and photodissociation. Well known examples include SF6 and the perfluorocarbons (PFCs) CF_4 and Teflon. SF_6 is used industrially in electrical switch gear and as an atmospheric tracer. CF_4 and C_2F_6 are released into the atmosphere as a by-product of aluminum manufacture. Several perfluoro compounds have been proposed as substitutes for the ozone-destroying Freons and halons; proposed substitutes include SF_6, c-C_4F_8, C_5F_1_2, and C_6F_1_4. These chemicals were chosen in part because they do not harm the stratospheric ozone layer and were therefore considered environmentally friendly. Recently, Ravishankara et al. reported that perfluoro compounds have significant global warming potential (GWP), contributing to the greenhouse effect due to strong infrared ...

1994-04-05

492

Characterization of the parameters at the origin of the chemical species hideout process at the fuel rod surface in boiling conditions  

International Nuclear Information System (INIS)

Current trends in nuclear power generation (and particularly in pressurized water reactors) are toward plant life extension and extended fuel burnup. A higher heat generation rate can induce local boiling regimes at the fuel rod surface in the hottest channels of the core, which can strongly modify the chemical environment of the cladding and influence the oxidation rate of zirconium alloys. Tests performed in out-of-pile loops under severe chemical and thermal-hydraulic conditions (nucleate boiling, higher lithium contents compared to PWRs) reveal two important phenomena: an increase of the oxidation rate of Zircaloy-4 cladding materials in 'high' lithiated environments; an enrichment of the chemical additives in the primary water (boron, lithium) at the surface of the cladding under nucleate boiling conditions. The latter phenomenon, also called 'hideout effect', is mainly controlled by some thermal hydraulic parameters ...

1999-12-01

493

Selective patterned growth of single-crystal organic nanowires of Ag-TCNQ with chemical raction method  

Energy Technology Data Exchange (ETDEWEB)

Abstract: We report for the selective-area chemical synthesis of semiconductor single-crystal organic nanowires of silver-tetracyanoquinodimethane (Ag-TCNQ). Straight and smooth Ag-TCNQ nanowires can be produced and patterned on micrometer and nanometer scale on silicon substrates covered with a thin layer of Ag film through the reaction of TCNQ and Ag in a simple gas-solid chemical reaction process. Ag-TCNQ nanowires are characterized by UV-vis, IR and Raman spectroscopy, respectively. The Ag-TCNQ nanowires grows preferentially along the [100] direction of strong - stacking of Ag-TCNQ molecules. Nanodevices based on these nanowires are fabricated using focus ion beam (FIB) technique. Electrical properties are characterized and I-V hysteresis is observed, which shows memory effect with electrical switching of three orders on-off ratio. These nanowires could be potential for use in optical storage, ultrahigh-density nanoscale memory and logic ...

2008-09-01

494

Methods and results of an evaluation of aquatic receptor risk at the Rocky Flats Environmental Technology Site, Golden, Colorado  

International Nuclear Information System (INIS)

The Rocky Flats Environmental Technology Site (RFETS) has historically released radionuclide chemicals of potential concern into the surrounding environment. The off-site environment was evaluated for Pu"2"3"9"/"2"4"0 and Am"2"4"1 occurrence. An evaluation of exposure and effects to the aquatic ecology within off-site areas including: Standley Lake, Great Western Reservoir, Mower Reservoir and portions of Big Dry Creek, Walnut Creek, and Woman Creek was performed for the completion of an Ecological Risk Assessment. Collocated sampling activities were performed for surface water, sediment, benthic macroinvertebrates and fish. Results of the analytical data were used to assess ongoing exposure and effects. Data collected to determine effects (chemical content of fish tissue, diversity and density of macroinvertebrate populations) provided some of the necessary information needed to evaluate risk. However, due to conditions of interfering stressor ...

1995-11-05

495

Ludwig's Applied Process Design for Chemical and Petrochemical Plants, 4th Edition - EA BOOKS  

Wastenet

...Ludwig's Applied Process Design for Chemical and Petrochemical Plants, 4th Edition - EA BOOKS nomographs, data charts and heuristics. About us | My EA Books | Contact us | Authors Home page Feature Books Books DVDs eBooks EA Books Publications Merchandise eJournals Terms and Conditions Subjects Chemical & Process Civil Computers Electrical & Electronics Environmental Management Mechanical Multi-disciplinary Quality Railways Structural Water Australian Authors Australian Rainfall ... Volume Two focuses on distillation and packed towers, and presents the methods and fundamentals of plant design along with supplemental mechanical and related data, nomographs, data charts and heuristics. The Fourth Edition is significantly expanded and updated, with new topics that ensure readers can analyze problems and find practical design methods and solutions to accomplish their process design objectives. It is a true application-driven book, ...

496

Influence of gamma irradiation and storage on the microbial load, chemical and sensory quality of chicken kabab  

Energy Technology Data Exchange (ETDEWEB)

Influence of gamma irradiation and storage on the microbial load, chemical and sensory quality of chicken kabab was investigated. Chicken kabab was treated with 0, 2, 4 or 6 kGy doses of gamma irradiation. Treated and untreated samples were kept in a refrigerator (1-4 deg. C). Microbiological, chemical and sensory characteristics of chicken kabab were evaluated at 0-5 months of storage. Gamma irradiation decreased the microbial load and increased the shelf-life of chicken kabab. Irradiation did not influence the major constituents of chicken kabab (moisture, protein and fats). No significant differences (p>0.05) were observed for total acidity between non-irradiated (control) and irradiated chicken kabab. Thiobarbitric acid (TBA) values (expressed as mg malonaldehyde (MDA)/kg chicken kabab) and volatile basic nitrogen (VBN) in chicken kabab were not affected by the irradiation. Sensory evaluation showed no significant differences between ...

2010-08-15

497

Electrical characteristics of AlxGa1-xN Schottky diodes prepared by a two-step surface treatment  

Science.gov (United States)

Near-ideal Schottky barrier contacts to n-type Al0.22Ga0.78N have been developed by a two-step surface treatment technique. Plasma etching of the AlxGa1-xN surface prior to Schottky metal deposition, combined with sequential chemical treatment of the etched surface, holds promise for developing high quality low-leakage Schottky contacts for low noise applications and for recessed gate high electron mobility transistors. In this work, the effect of postetch chemical treatment of the n-type Al0.22Ga0.78N surface on the performance of the Ni/Au based Schottky contact has been investigated. Three different types of chemical treatment: viz, reactive ion etching, reactive ion etching plus dipping in hot aqua regia, and reactive ion etching plus dipping in hot KOH, are studied. Detailed current-voltage studies of three different surface treated diodes and a comparison with as-deposited diodes reveal significant improvement in the ...

2004-09-01

498

Chemical-equilibrium calculations for aqueous geothermal brines  

Energy Technology Data Exchange (ETDEWEB)

Results from four chemical-equilibrium computer programs, REDEQL.EPAK, GEOCHEM, WATEQF, and SENECA2, have been compared with experimental solubility data for some simple systems of interest with geothermal brines. Seven test cases involving solubilities of CaCO/sub 3/, amorphous SiO/sub 2/, CaSO/sub 4/, and BaSO/sub 4/ at various temperatures from 25 to 300/sup 0/C and in NaCl or HCl solutions of 0 to 4 molal have been examined. Significant differences between calculated results and experimental data occurred in some cases. These differences were traced to inaccuracies in free-energy or equilibrium-constant data and in activity coefficients used by the programs. Although currently available chemical-equilibrium programs can give reasonable results for these calculations, considerable care must be taken in the selection of free-energy data and methods of calculating activity coefficients.

1981-05-01

499

Chemical reactivity of silicon nitride with steel and oxidised steel between 500 and 1200 C  

Energy Technology Data Exchange (ETDEWEB)

The chemical interaction of a Si{sub 3}N{sub 4} ceramic with pristine and oxidised 100Cr6 steel was studied by means of static interaction couple experiments between 500 and 1200 C. Si{sub 3}N{sub 4} was not chemically stable in contact with oxidised steel at elevated temperatures, and reacts with the formation of N{sub 2}, SiO{sub 2} and/or Fe{sub 2}SiO{sub 4} at temperatures at and above 1000 C. At 700 and 500 C, Si diffusion into the oxide layer indicated the dissociation of the Si{sub 3}N{sub 4} ceramic. Si{sub 3}N{sub 4} also dissociated in contact with pristine steel. In the temperature region between 700 and 1100 C, the Si dissolves and diffuses into the steel whereas a nitrogen pressure is built-up in the voids of the metal-ceramic interface, limiting the degree of interaction. Above 1100 C, the nitrogen dissolves and diffuses into the steel as well, enhancing the reactivity and resulting in the formation of a strong metal-ceramic ...

2000-04-15

500

(Packaging regulations for chemical explosives)  

Energy Technology Data Exchange (ETDEWEB)

The purpose of the trip was to visit Nobel Chemicals in Sweden and to confer with the Department of Transportation personnel in Sweden and in England on the technical and regulatory problems in the bulk shipping of the high explosives RDX and HMX. It is customary in the United States (US) to add isopropyl alcohol to the bulk shipment of water-wet high explosives RDX and HMX. The explosives are packed in cloth bags which are placed in plastic-lined fiber drums. The addition of alcohol presumably prevents mildewing of cloth bags and freezing of the wet explosives in cold weather. In Europe, however, these explosives are shipped in polyethylene-lined fiber drums with not less than 15% water only, even in cold weather. Water-wet frozen explosives have not proved to be any more sensitive than its unfrozen counterpart and no mildew problem has been encountered. It looks promising that the US Department of Transportation regulations can be changed to permit the bulk ...

1988-02-17