UK PubMed Central (United Kingdom)

Remote sensing data over North America document the ubiquity of secondary aerosols resulting from a combination of primary biogenic and anthropogenic emissions. The spatial and temporal distribution...Full Text Available

Environmental Research Database

DescriptionChamber studies have shown that biogenic organic compounds, including isoprene, are capable of producing secondary organic aerosol in significant quantities. This is surprising as isoprene and its photo-oxidation products have relatively high vapour pressures. However, it is very important as isoprene has the largest global emissions flux of any biogenic hydrocarbon, most of which is in the tropics. Despite this, secondary organic aerosol has been poorly studied in tropical regions with only [continued...

Wastenet

heterogeneity bias Static models: Other models:

UK PubMed Central (United Kingdom)

Lactobacillus buchneri ST2A vigorously decarboxylates histidine to the biogenic amine histamine, which is excreted into the medium. Cells grown in the presence of histidine generate both a transmembrane...Full Text Available

KoreaScience (Korea)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Role of microelements in coal in connection with their combustion in power stations, gasification and hydrogenation is discussed from the standpoint of environmental pollution and effects on technological parameters. In the wastes from fossil-fuel power stations there are biogenic and toxic elements (Be, B, Pb, etc.) present, which eventually go into the soil. Analyses showed that coal from the Kuznetsk, Donetsk, Ehkibastuz and Kansk-Achinsk basins which are used for power, have a relatively low level of biogenic and toxic microelements, e.g. Ba, B, Mn, Pb, Co, Ni, V, Cu, Y. Coal reactivity in gasification and hydrogenation is discussed. The catalytic effect of several microelements in coal gasification and hydrogenation is established. A geochemical multiplicative indicator is presented which makes quantitative evaluation of the suitability of coals for hydrogenation possible. 17 references.

UK PubMed Central (United Kingdom)

This study examined changes in the degree of positive bias in self-perceptions of previously-diagnosed 8 to 13 year-old children with attention-deficit/hyperactivity disorder (ADHD) (n=513)...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundThe genomes of prokaryotes and lower eukaryotes display a very strong 11 bp periodic bias in the distribution of their nucleotides. This bias is present throughout a given...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The authors report a two-temperature RF bias stress test on nominal 1.2 W 7.5 GHz GaAs/AlGaAs HBT unit cell amplifiers. MTTF`s of 2020 and 1340 hours were obtained at Tj = 218{degrees}C and 245{degrees}C, respectively, under nominal input bias. An activation energy of 0.42 eV is estimated, consistent with published results for similar devices under DC bias stress.

British Library Electronic Table of Contents (United Kingdom)

Pippenger (2011) recently proposed a solution to the longstanding forward-bias puzzle. He argues that the puzzling estimates obtained using the standard equation for the efficient markets hypothesis are due to omitted variable bias. He identifies the missing variables as the future change in the forward exchange rate and the future interest differential. When these are added to the standard equation, he finds a one-to-one relationship between the future change in the spot rate and the forward premium. However, we argue that his equation can only test covered interest parity and offers no insight into the forward-bias puzzle.

British Library Electronic Table of Contents (United Kingdom)

Abstract: This article argues that Pippenger's (2011) ''Solution to the forward-bias puzzle'' must be regarded as an econometric explanation of the famous puzzle, although it does not offer an exhaustive economic answer to it. Some of Pippenger's (2011) findings are reproduced and established in a cointegrated multiple time series model. It is suggested that economists should stop trying to working out the forward-bias puzzle and start looking for fundamentally better models of foreign exchange rate determination. A tentative alternative is provided.

International Nuclear Information System (INIS)

We investigate how 'extra' or 'excess' central light in the surface brightness profiles of cusp or power-law elliptical galaxies relates to the profiles of ellipticals with cores. The envelopes of cusp ellipticals are established by violent relaxation in mergers acting on stars present in gas-rich progenitor disks, while their centers are structured by the relics of dissipational, compact starbursts. Ellipticals with cores are formed by the subsequent merging of the now gas-poor cusp ellipticals, with the fossil starburst components combining to preserve a dense, compact component in these galaxies as well (although mixing of stars smooths the transition from the outer to inner components in the profiles). By comparing extensive hydrodynamical simulations to observed profiles spanning a broad mass range, we show how to observationally isolate and characterize the relic starburst component in core ellipticals. Our method recovers the younger starburst population, demonstrating that ...

International Nuclear Information System (INIS)

A biogenic method for the treatment of uranium mill effluents containing toxic amounts of Mn"2 and "2"2"6Ra is described. The acidic tailings from the uranium mills are generally neutralised with lime and the overflow waters from tailing ponds at the discharge point, consisting of Mn"2"+ (>10 mg l"-"1) and "2"2"6Ra (> 3.0 pCi l"-"1), need further treatment before disposing off to the public utility. Arthrobacter sp. has been used for precipitating Mn"2"+ as hydrous oxide of manganes (MnO_2#centre dot#nH_2O) and along with "2"2"6Ra also gets precipitated. The effluent after bacterial treatment consisted of Mn"2"+ and "2"2"6Ra within the range of allowed concentrations as per the I.C.R.P. (International Committee of Radiological Protection) and MPC (maximum permissible concentration) standards (Mn"2"+ 95% of "2"2"6Ra could be precipitated using this method. (author). 11 refs.; 4 figs.; 4 tabs.

Energy Technology Data Exchange (ETDEWEB)

The performance of more than 3,000 offshore platforms in the Gulf of Mexico was observed during the passage of Hurricane Andrew in August 1992. This event provided an opportunity to test the procedures used for platform analysis and design. A global bias was inferred for overall platform capacity and loads in the Andrew Joint Industry Project (JIP) Phase 1. It was predicted that the pile foundations of several platforms should have failed, but did not. These results indicated that the biases specific to foundation failure modes may be higher than those of jacket failure modes. The biases in predictions of foundation failure modes were therefore investigated further in this study. The work included capacity analysis and calibration of predictions with the observed behavior for 3 jacket platforms and 3 caissons using Bayesian updating. Bias factors for two foundation failure modes, lateral shear and ...

British Library Electronic Table of Contents (United Kingdom)

This paper investigates whether China has reached postnatal nutrient intake equality between boys and girls, despite an exceptionally high ratio of boys to girls at birth, after dramatic technological advances in prenatal sex determination, rapid increases in income, and improved educational opportunities for females. Dominance methods applied to data from the Chinese Health and Nutrition Surveys (selected years 1991-2004) reveal no bias in calorie consumption between girls and boys. We find some weak evidence of protein bias toward boys in 1991, but it disappeared by 2004. (JEL I32, O15, N35)

International Nuclear Information System (INIS)

It is experimentally demonstrated that a relatively strong ion-rich sheath formed at a fixed negative bias of the grid can be changed to a rather weak ion sheath (sheath potential weakly retards electrons) only by increasing the discharge voltage in the system. At sufficiently high negative grid bias, an increase of discharge voltage enhances the ion collection current at the grid. An explanation is put forward in support of this experimental observation. A slight density enhancement with a fall in plasma electron temperature is also observed with the increasing negative grid bias. (authors)

International Nuclear Information System (INIS)

Monte Carlo criticality calculations have been performed for over 50 years for reactor physics and criticality safety applications. With today's faster computers, these calculations are being carried out to greater precision (smaller uncertainties) in keff, and detailed distributions of power and reaction rates are being computed routinely. This paper provides a review of the fundamental theory of Monte Carlo criticality calculations, with guidance on practical methods for: (1) assuring convergence of both keff and the source distribution, (2) minimizing the bias in keff and reaction rate distributions, and (3) dealing with the under-prediction bias in uncertainties for keff and reaction rate distributions. (authors)

British Library Electronic Table of Contents (United Kingdom)

Motivation: It is commonplace for authors to propose a new classification rule, either the operator construction part or feature selection, and demonstrate its performance on real data sets, which often come from high-dimensional studies, such as from gene-expression microarrays, with small samples. Owing to the variability in feature selection and error estimation, individual reported performances are highly imprecise. Hence, if only the best test results are reported, then these will be biased relative to the overall performance of the proposed procedure. Results: This article characterizes reporting bias with several statistics and computes these statistics in a large simulation study using both modeled and real data. The results appear as curves giving the different reporting biases as...

UK PubMed Central (United Kingdom)

Genomic imprinting refers to the parent-of-origin-specific epigenetic marking of a number of genes. This epigenetic mark leads to a bias in expression between maternally and paternally inherited imprinted...Full Text Available

Science.gov (United States)

... adaptive method called Shortest Queue plus Bias ... routing problem under stochastic traffic demands have ... of permits allocated to a node or terminal ...

Science.gov (United States)

... study is to collect data in previously harvested timber stands to quantify the differences in herbaceous diversity ... ...

Energy Technology Data Exchange (ETDEWEB)

We have used the unique spatial sensitivity of polarized neutron and soft x-ray beams in reflection geometry to measure the depth dependence of magnetization across the interface between a ferromagnet and antiferromagnet. The new uncompensated magnetization near the interface responds to applied field, while the uncompensated spins in the antiferromagnetic bulk are pinned, thus providing a means to establish exchange bias.

Energy Technology Data Exchange (ETDEWEB)

A series of experiments have been conducted on AISI 5140 low alloy steel using a hollow cathode discharge-assisted plasma nitriding apparatus with the aim of elucidating the role of substrate bias voltages in plasma nitriding process. For comparison, some samples were nitrided with applied substrate bias (-50 V) while other samples were nitrided at floating potential. Treatments were carried out in NH{sub 3} atmosphere of 150 Pa at temperatures ranging from 450 {sup o}C to 550 {sup o}C for 2 h, 4 h, and 6 h. The nitrided samples were characterized by optical microscopy, X-ray diffraction and micro-hardness measurement. The corrosion behaviors were evaluated using anodic polarization tests in 3.5% NaCl solution. The results showed that the microstructure and phase constituents of the nitride layers were strongly influenced by the bias voltages. It was also demonstrated that the better corrosion resistance with a thicker ...

Energy Technology Data Exchange (ETDEWEB)

We present two new techniques that enhance conventional focused ion beam (FIB) system capabilities for integrated circuit (IC) analysis: in situ electrical biasing and voltage contrast imaging. We have used in situ electrical biasing to enable a number of advanced failure analysis applications including (1) real time evaluation of device electrical behavior during milling and deposition, (2) verification of IC functional modifications without removal from the FIB system, and (3) ultraprecision control for cross sectioning of deep submicron structures, such as programmed amorphous silicon antifuses. We have also developed FIB system voltage contrast imaging that can be used for a variety of failure analysis applications. The use of passive voltage contrast imaging for defect localization and for navigation on planarized devices will be illustrated. In addition, we describe new, biased voltage contrast imaging techniques and ...

Energy Technology Data Exchange (ETDEWEB)

This final report for the Swiss Federal Office of Energy (SFOE) presents the results of a project that involves the building of a joint biogas plant serving 60 farmers and industrial companies with an annual processing capacity of 45,000 tons. The plant is to produce biogas to be fed into the gas mains and will not only reduce nutrient loading in a region with an extensive livestock industry but also reduce carbon dioxide emissions by using the gas as a motor fuel. The importance of the project with respect to both the environment and energy policy-making is discussed and the costs involved are examined. Details are presented on the technology used and on the material flows involved. Figures are quoted on energy production. The various biogenic substrates used, such as food wastes, waste oils, cereal wastes and used mushroom substrates, are discussed, as is the use of the solid and liquid outputs of the digester in farming activities.

Energy Technology Data Exchange (ETDEWEB)

Ozone plays a critical role in both the chemistry and radiation balance of the troposphere. Understanding the factors controlling tropospheric ozone levels is critical to our understanding of a variety of issues in global chemistry and climate change. Chlorine atoms have the potential to contribute significantly to the ozone balance in the free troposphere. They can react directly with ozone or alternately, with organics and may actually lead to the formation of ozone in the presence of sufficient NO. Reactions of alkali halides in sea salt particles are a potential source of atomic chlorine, hence reactions of these alkali halides, especially those producing precursors to atomic chlorine, are of great interest. Finally, the mechanisms, intermediates and products of the Cl-biogenic reactions are unknown; these could serve as unique markers of chlorine atom chemistry in the troposphere, and hence are important to define.

British Library Electronic Table of Contents (United Kingdom)

Results in this study are consistent with those of Murdock and his colleagues who clearly demonstrated that clonidine, an agonist of octopaminergic receptors in some insects, significantly increases sucrose feeding. Their studies, however, did not examine the effect of clonidine on protein feeding. Injection of a 20mg/ml/fly dose of clonidine significantly reduces protein feeding in both sexes of Phormia regina, instead of stimulating feeding as is observed with carbohydrate feeding. The manner in which the flies are fed prior to starvation and the method of testing influences the amounts of diet consumed. It is proposed that the biogenic amines influence the state of hunger (i.e., protein versus carbohydrates) while other chemicals and neural mechanisms (i.e., such as sulfakinins and stre...

British Library Electronic Table of Contents (United Kingdom)

To the best of our knowledge, this is the first report on the chemical and microbial properties of traditional Iranian fish sauce, mahyaveh. Fish sauce samples used in this study originated from five different locations in the Southern part of Iran. The pH of mahyaveh samples from different locations was in the range of 4.89-7.55 and NaCl concentration was in the range of 7.48-17.1%. The overall mean of TVB-N in all the samples tested was 3098 mg/kg. Histamine, with the overall mean of 2662 mg/kg, was found to be the main biogenic amine in the Iranian fish sauce. The high histamine content can be related to the high levels of bacterial count especially enterobacteriaceae (overall mean of 3.41 log cfu/g) and lactic acid bacteria (overall mean of 4.13 log cfu/g) in this product. Spermidine w...

British Library Electronic Table of Contents (United Kingdom)

A large database (507 station-years) of daily suspended particulate matter (SPM) concentration and discharge data from 36 stations on river basins ranging from 600?km2 to 600,000?km2 in size (USA and Europe) was collected to assess the effects of SPM transport regime on bias and imprecision of flux estimates when using infrequent surveys and the discharge-weighted mean concentration method. By extracting individual SPM concentrations and corresponding discharge values from the database, sampling frequencies from 12 to 200 per year were simulated using Monte Carlo techniques. The resulting estimates of yearly SPM fluxes were compared to reference fluxes derived from the complete database. For each station and given frequency, bias was measured by the median of relative errors between estima...

Energy Technology Data Exchange (ETDEWEB)

Various statistical methods for the estimation of the mean lifetimes of charmed particles have been considered. It is shown that the usual estimates of the maximum likelihood in some cases do not exist or may have rather great positive bias, if the statistics are low. Alternative estimates of the mean lifetime tau are discussed. Among them the 'jackknife' estimate of tau is considered. The minimum variance unbiased estimates of the average rate of decay 1/tau have been derived for some particular cases. It is also shown that the usual estimate of the ratio of the mean lifetimes of different kinds of particles may alos have a bias when the statistics are poor. Two methods of reducing this bias have been proposed. (orig.).

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.)

British Library Electronic Table of Contents (United Kingdom)

North American design codes are now committed to the development of load and resistance factor design (LRFD) for reinforced soil structures including internal stability limit states. Reliability-based analysis is required to carry out these calibrations. A framework for LRFD calibration has been proposed by the writers that requires bias statistics for load and resistance terms for each limit state function. In this paper the formulation of the limit state for reinforcement tensile rupture is developed and the component strength-reduction bias statistics identified. The paper describes how to compute bias statistics from project-specific installation damage trials for use in reliability-based design for the reinforcement rupture limit state or using data from multiple sources for LRFD cali...

UK PubMed Central (United Kingdom)

Polyploidy is an important force in the evolution of flowering plants. Genomic merger and doubling induce an extensive array of genomic effects, including immediate and long-term alterations in the...Full Text Available

UK PubMed Central (United Kingdom)

Most codon indices used today are based on highly biased nonrandom usage of codons in coding regions. The background of a coding or noncoding DNA sequence, however, is fairly random, and can be characterized...Full Text Available

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

International Nuclear Information System (INIS)

Samples prepared using the focused ion beam (FIB) inevitably contain the surface damage induced by energetic Ga"+ ions. An effective method of removing the surface damage is demonstrated using a plasma cleaner, a device which is widely used to minimize the surface contamination in scanning transmission electron microscopy (STEM). Surface bombardment with low-energy Ar"+ ions was induced by biasing the sample immersed in the plasma source, so as to etch off the surface materials. The etch rates of SiO_2, measured with a bias voltage of 100-300 V, were found to vary linearly with both the time and bias and were able to be controlled from 1.4 to 9 nm/min. The removal of the Ga residue was confirmed using energy dispersive spectroscopy (EDS) after the plasma processing of the FIB-prepared sample. When the FIB-prepared sample was processed via plasma etching for 10 min with a bias of 150 V, the surface Ga ...

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

UK PubMed Central (United Kingdom)

Cytokines produced by Th2 cells are responsible for the pathogenesis of asthma. Th1-biased immune responses caused by attenuated salmonella have the potential to relieve asthmatic symptoms. We evaluated...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundBrucellosis is a zoonosis of veterinary, public health and economic significance in most developing countries. Human brucellosis is a severely debilitating disease that...Full Text Available

UK PubMed Central (United Kingdom)

The study design included an in vivo laboratory study. The objective of the study is to quantify the kinematics of the lumbar spinous processes in asymptomatic patients during un-restricted functional...Full Text Available

International Nuclear Information System (INIS)

The sheath plasma characteristics changing with the negative bias applied to the substrate during electron cyclotron resonance plasma nitriding are studied. The sheath characteristics obtained by a Langmuir single probe and an ion energy analyzer show that when the negative bias applied to the substrate is increasing, the most probable energy of ions in the sheath and the full width of half maximum of ions energy distribution increase, the thickness of the sheath also increases, whereas the saturation current of ion decreases. It has been found from the optical emission spectrum that there are strong lines of N_2 and N_2"+. Based on the experiment results the mechanism of plasma nitriding is discussed

Energy Technology Data Exchange (ETDEWEB)

Monte Carlo methods have been used to compute k{sub eff} and the fundamental mode eigenfunction of critical systems since the 1950s. While such calculations have become routine using standard codes such as MCNP and SCALE/KENO, there still remain 3 concerns that must be addressed to perform calculations correctly: convergence of k{sub eff} and the fission distribution, bias in k{sub eff} and tally results, and bias in statistics on tally results. This paper provides a review of the fundamental problems inherent in Monte Carlo criticality calculations. To provide guidance to practitioners, suggested best practices for avoiding these problems are discussed and illustrated by examples.

Energy Technology Data Exchange (ETDEWEB)

The WEGA stellarator is used to confine low temperature, overdense (densities exceeding the cut-off density of the heating wave) plasmas by magnetic fields in the range of B=50-500 mT. Microwave heating systems are used to ignite gas discharges using hydrogen, helium, neon or argon as working gases. The produced plasmas have been analyzed using Langmuir and emissive probes, a single-channel interferometer and ultra-high resolution Doppler spectroscopy. For a typical argon discharge in the low field operation, B=56 mT, the maximum electron density is n{sub e}{proportional_to}10{sup 18} m{sup -3} with temperatures in the range of T=4-12 eV. The plasma parameters are determined by using Langmuir probes and are cross-checked with interferometry. It is demonstrated within this work that the joint use of emissive probes and ultra-high resolution Doppler spectroscopy allows a precise measurement of the radial electric field. The focus of this work is on demonstrating the ability to modify the ...

Energy Technology Data Exchange (ETDEWEB)

Examination of a chloroform extract of Dracaena loureiri Gagnep (Agavaceae), a Thia medicinal plant possessing antibacterial activity, has led to the isolation of fifteen flavenoids. The biogenic relationships among these flavenoids isolated were briefly discussed. Definition of the skeleton and the unambiguous assignment of all of the protons of the isolates was achieved through extensive 2D-homonuclear chemical shift correlation, nuclear Overhauser effect (NOE) difference spectroscopy and 2D-NOE experiments. The {sup 1}H and {sup 13}C NMR spectra of staurosporine, a potent biologically active agent from Streptomyces staurosporeus, were unambiguously assigned by using 2D homonuclear chemical shift correlation, NOE, {sup 1}H-detected heteronuclear multiple-quantum coherence via direct coupling and via multiple-bond coupling for resonance assignments of protonated and nonprotonated carbons, respectively. S. Staurosporeus was found to utilize endogenous and exogenous ...

Energy Technology Data Exchange (ETDEWEB)

The terrestrial biosphere can significantly affect the exchange of water and energy at the biosphere-atmosphere interface. Additionally, the land cover type can affect regional atmospheric chemistry and climate via biogenic volatile organic carbon (VOC) emissions and their formation of secondary organic aerosols. The broad goal of this study is to investigate the impact of land cover and vegetation changes on these specific chemistry and climate effects. The Common Land Model (CLM) is used to parameterize the biosphere-atmosphere interface over the Shanghai region in China. Phase 1 of this study, described in this report, generates input parameters for this model based on a time series of actual and derived parameters. Atmospheric forcing data are generated on an hourly temporal resolution based on a 20-year series of monthly and daily averages. Surface data, including land cover/land use and soil information, are generated for two scenarios: (a) the current land ...

Science.gov (United States)

Inductively coupled fluorocarbon (CF4/Ar and C4F8/Ar) plasmas were used to etch HfO2, which is a promising high-dielectric-constant material for the gate of complementary metal-oxide-semiconductor devices. The etch rates of HfO2 in CF4/Ar plasmas exceeded those in C4F8/Ar plasmas. The tendency for etch rates to become higher in fluorine-rich (high F/C ratio) conditions indicates that HfO2 can be chemically etched by fluorine-containing species. In C4F8/Ar plasmas with a high Ar dilution ratio, the etch rate of HfO2 increased with increasing bias power. The etch rate of Si, however, decreasd with bias power, suggesting that the deposition of carbon-containing species increased with increasing the power and inhibited the etching of Si. The HfO2/Si selectivity monotonically increased with increasing power, then became more than 5 at the highest tested bias power. The carbon-containing species to inhibit etching of Si play an ...

British Library Electronic Table of Contents (United Kingdom)

Background: Quantifying HIV levels in mucosal secretions is essential to study compartmentalized expression of HIV and facilitate development of intervention strategies to prevent disease progression and transmission. Objectives: To develop a sensitive, reliable, and cost-effective technique to quantify HIV from blood and vaginal secretions that is compatible with efficient implementation in clinical research environments. Study design: A sensitive, reliable, internally-controlled real-time reverse transcriptase (RT) PCR assay, which uses the HIV-1 pol gene as a target (Hpol assay) was developed to quantify HIV levels in plasma and genital secretions, and compared to the widely used Roche Amplicor(TM) HIV-1 Monitor assay. In addition, a simplified method of sample collection and processing...

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

Quantitative, experimentally based assessments of the biases of the methods used to develop the neutronics design of the FTR are presented together with brief descriptions of the design methods. Uncertainties in biases have been established that are sufficiently small to allow a high degree of confidence in the nuclear design. Experimental data for these assessments have been developed in full-scale zero-power mockups of the final design of the reactor, except for Doppler data from SEFOR. Temperature, power coefficient, and stability methods evaluations are necessarily deferred to acceptance testing during initial startup of the FTR. Sodium voiding and small sample worths continue to be the technical areas of greatest complexity with least experiment-theory correlation. Critical mass, Doppler effects, control rod worth, and spatial power distribution have generally good experiment-theory correlations.

British Library Electronic Table of Contents (United Kingdom)

Many studies on multisensory processes have focused on performance in simplified experimental situations, with a single stimulus in each sensory modality. However, these results cannot necessarily be applied to explain our perceptual behavior in natural scenes where various signals exist within one sensory modality. We investigated the role of audio-visual syllable congruency on participants? auditory localization bias or the ventriloquism effect using spoken utterances and two videos of a talking face. Salience of facial movements was also manipulated. Results indicated that more salient visual utterances attracted participants? auditory localization. Congruent pairing of audio-visual utterances elicited greater localization bias than incongruent pairing, while previous studies have repor...

Energy Technology Data Exchange (ETDEWEB)

The original objective of our EMSP research was to design, develop, and test new in situ field permeameters for use in spatial variability studies of unsaturated hydraulic properties. We initially focused on activities related to development and testing of techniques for inverting permeameter data, development of numerical tools for data inversion, error evaluation for permeameter design, and permeameter component design. However, the results of error evaluations for permeameter design caused us to redirect our research, and reformulate our research objectives. We discovered that small, simple measurement errors lead to significant bias in the estimated hydraulic properties and their spatial statistics. Our reformulated research objective became the evaluation of the origin, impact and relevance of spatial bias in field-and laboratory-estimated unsaturate hydraulic properties, with an emphasis on spatial statistics and the resulting predictions ...

CERN Document Server

We investigate the extent to which the pure magnification effect of gravitational lensing can be extracted from galaxy clustering statistics, by a nulling method which aims to eliminate terms arising from the intrinsic clustering of galaxies. The aim is to leave statistics which are free from the uncertainties of galaxy bias. We find that nulling can be done effectively, leaving data which are relatively insensitive to uncertainties in galaxy bias and its evolution, leading to cosmological parameter estimation which is effectively unbiased. This advantage comes at the expense of increased statistical errors, which are in some cases large, but it offers a robust alternative analysis method to cosmic shear for cosmological imaging surveys designed for weak lensing studies, or to full modelling of the clustering signal including magnification effects.

Energy Technology Data Exchange (ETDEWEB)

The Fast Flux Test Facility (FFTF) core loading during its ninth operating cycle was significantly different from that of previous cycles because of the presence of the Core Demonstration Experiment (CDE). The CDE consists of a number of axially blanketed fuel assemblies and internal blankets prototypic of advanced oxide cores in Liquid Metal Reactors (LMR). In preparation for the Cycle 9 reload design effort, a careful assessment of control rod worth and reactivity calculations for Cycles 1 through 8 was made. The goal of this study was to establish calculational biases and reduce uncertainties factored into the reload design calculations. These analyses helped assure that the operational objectives for Cycle 9 were met.

UK PubMed Central (United Kingdom)

Variability in motor performance decreases with practice but is never entirely eliminated, due in part to inherent motor noise. The present study develops a method that quantifies how performers...Full Text Available

UK PubMed Central (United Kingdom)

The interactions between biochemical processes and mechanical signaling play important roles during various cellular processes such as wound healing, embryogenesis, metastasis, and cell migration. While...Full Text Available

UK PubMed Central (United Kingdom)

ObjectiveTo investigate and to quantify the relationship between hospital costs and health outcomes for patients with acute myocardial infarction (AMI) in Veterans Health Administration...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundSmall laboratory fish share many anatomical and histological characteristics with other vertebrates, yet can be maintained in large numbers at low cost for lifetime studies....Full Text Available

UK PubMed Central (United Kingdom)

BackgroundConducted as part of the Urologic Diseases in America project whose aim was to quantify the burden of urologic diseases on the American public, this study focuses on Veterans...Full Text Available

UK PubMed Central (United Kingdom)

School buses contribute substantially to childhood air pollution exposures yet they are rarely quantified in epidemiology studies. This paper characterizes fine particulate matter (PM_2.5)...Full Text Available

Science.gov (United States)

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

UK PubMed Central (United Kingdom)

Spinal cord injury (SCI) is a debilitating disorder, which produces profound deficits in volitional motor control. Following medical stabilization, recovery from SCI typically involves long term rehabilitation....Full Text Available

UK PubMed Central (United Kingdom)

Genetic effects on mechanical properties have been demonstrated in rodents, but not confirmed in primates. Our aim was to quantify the proportion of variation in vertebral trabecular bone mechanical...Full Text Available

UK PubMed Central (United Kingdom)

Many patients are currently suffering from nickel (Ni)-induced allergic contact dermatitis (ACD). There have been few Korean studies dealing with the threshold of Ni-induced ACD and quantifying the...Full Text Available

UK PubMed Central (United Kingdom)

Pseudomonas mandelii liquid cultures were studied to determine the effect of pH and temperature on denitrification gene expression, which was quantified by quantitative reverse transcription-PCR....Full Text Available

UK PubMed Central (United Kingdom)

The utility of a two-photon optical fiber fluorescence probe (TPOFF) for sensing and quantifying tumor fluorescent signals was tested in vivo. Xenograft tumors were developed in athymic mice using MCA207...Full Text Available

Science.gov (United States)

Quantitative metallography is often used to confirm the proper processing of aerospace metallic materials. A microstructural feature of great importance for titanium alloys processed in the alpha-beta phase field is the volume fraction of primary alpha. S...

UK PubMed Central (United Kingdom)

BackgroundKinematic and kinetic measurements used in laboratory settings can quantify upper extremity movement impairment following stroke, but their relationship...Full Text Available

UK PubMed Central (United Kingdom)

The objectives of this study were to quantify the effect of 16 ppm of dietary monensin on milk production and composition of dairy cows, and to investigate factors having a potential impact on this...Full Text Available

International Nuclear Information System (INIS)

Werner states are paradigmatic examples of quantum states and play an innovative role in quantum information theory. In investigating the correlating capability of Werner states, we find the curious phenomenon that quantum correlations, as quantified by the entanglement of formation, may exceed the total correlations, as measured by the quantum mutual information. Consequently, though the entanglement of formation is so widely used in quantifying entanglement, it cannot be interpreted as a consistent measure of quantum correlations per se if we accept the folklore that total correlations are measured (or rather upper bounded) by the quantum mutual information.

Energy Technology Data Exchange (ETDEWEB)

The Waste Acceptance Preliminary Specifications (WAPS) require that the DWPF estimate the inventory of long-lived radionuclides present in the waste glass, and report the values in the Waste Form Qualification Report. In this report, conservative (biased high) estimates of the radionuclide inventory of glass produced from waste currently in the Tank Farm are provided. In most cases, these calculated values compare favorably with actual data. In those cases where the agreement is not good, the values reported here are conservative.

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.

Energy Technology Data Exchange (ETDEWEB)

The authors investigate the breakdown luminescence spectra in reverse-biased p-n heterojunctions based on gallium and aluminum phosphides and arsenides for the purpose of determining their behavior as lasing and photodetection materials. Data are given on temperature coefficients, band gap structure, bremsstrahlung, hot carrier mobility and photon emission, and transition and recombination parameters.

Energy Technology Data Exchange (ETDEWEB)

A simple and continuous model for the on-state current of polysilicon thin-film transistors, suitable for implementation in circuit simulators, is presented. The model includes the potential barrier at the grain boundaries, the channel length modulation and the excess current due to impact ionization. Comparison between measured output characteristics and the model shows excellent agreement over wide range of bias voltages and for devices with different gate lengths.

Energy Technology Data Exchange (ETDEWEB)

In this work we present the electrical characterization of non self-aligned p-channel thin film transistors fabricated by using laser doping technique for source/drain contact formation and gate oxide deposited at room temperature by Electron Cyclotron Resonance Plasma Enhanced Chemical Vapour Deposition. These techniques are suitable for a very low temperature process for TFT fabrication. The output characteristics show a current increase at high drain voltage ('kink' effect) rather moderate, if compared to self aligned polysilicon TFTs, probably due to the gradual doping profile induced by laser doping process. After bias stress at low gate voltage and high drain voltage condition a strong reduction of kink current has been observed in the output characteristics at high drain voltage, whereas minor changes has been observed in the transfer characteristics. This behaviour is similar to what observed in n-channel Gate Overlapped Thin Film ...

Energy Technology Data Exchange (ETDEWEB)

Systematic studies of the NdFeAsOF superconducting energy gap using point-contact Andreev-reflection (PCAR) spectroscopy are presented. At low temperatures the PCAR conductance spectra show a pair of gap-like peaks at about {+-} (4-7) mV and in most cases also a pair of humps at around {+-} 10 mV. Fits to the s-wave two-gap model of the PCAR conductance allowed to determine two superconducting energy gaps in the system. However, the energy-gap features disappear at T* = 15-20 K, much below the particular T{sub c} of the junction under study. At T* a zero-bias conductance (ZBC) peak emerges, which at higher temperatures usually overwhelms the spectrum with an intensity significantly higher than the conductance signal at lower temperatures. Possible causes of this unexpected temperature effect are discussed. In some cases the conductance spectra show just a reduced conductance around the zero-bias voltage, the effect persisting well above the ...

Energy Technology Data Exchange (ETDEWEB)

PVD-chromium-nitride coated samples of substrates of the magnesium alloy AZ91hp and the roller and ball bearing steel 100Cr6 were investigated regarding structure, mechanical characteristics, adhesion and internal stresses. For the coatings the parameters layer thickness and substrate BIAS voltage were varied. Both substrate materials were coated in one lad. Results of the X-ray analysis of the internal stresses show significant differences between the coated magnesium and the coated steel substrates. In the case of the variation of the substrate BIAS voltage, for the coated steel a dependency of the internal stresses to coating parameters could be obtained. For the coated magnesium no dependency was recognizable. The coating structure was examined with scanning electron microscopy. Element depth profiles of the coated samples were performed with SIMS. (orig.)

International Nuclear Information System (INIS)

Inductively coupled plasma etching of InGaP, AlInP and AlGaP in BI_3 or BBr_3 discharges was investigated as a function of source power, dc chuck bias and plasma composition. InGaP etches at the fastest rates (>6000 Angstrom min"-"1) in both chemistries, followed by AlGaP. It is found that AlInP provides an excellent etch stop for the other two materials in both mixtures. The InGaP surface morphology improves with increasing BI_3 or BBr_3 content, and with increasing dc chuck bias. The etched features for this material are highly anisotropic. Etch selectivities for InGaP over SiO_2 and SiN_x of #>=#8 are obtained in both plasma chemistries, and there is no etch incubation time with either mixture, indicating that both can scavenge the native oxide on InGaP, AlGaP and AlInP. copyright 1998 American Vacuum Society.

CERN Document Server

We propose a method to determine the cosmic mass density Omega from redshift-space distortions induced by large-scale flows in the presence of nonlinear clustering. Nonlinear structures in redshift space such as fingers of God can contaminate distortions from linear flows on scales as large as several times the small-scale pairwise velocity dispersion sigma_v. Following Peacock & Dodds (1994), we work in the Fourier domain and propose a model to describe the anisotropy in the redshift-space power spectrum; tests with high-resolution numerical data demonstrate that the model is robust for both mass and biased galaxy halos on translinear scales and above. On the basis of this model, we propose an estimator of the linear growth parameter beta = Omega^0.6/b, where b measures bias, derived from sampling functions which are tuned to eliminate distortions from nonlinear clustering. The measure is tested on the numerical data and found to recover ...

Energy Technology Data Exchange (ETDEWEB)

The effects of gate and drain bias stresses on thin film transistors fabricated in polysilicon films crystallized using the advanced sequential lateral solidification excimer laser annealing (SLS ELA) process, which yields very elongated polysilicon grains and allows the fabrication of TFTs without grain boundary barriers to current flow, are investigated as a function of the active layer thickness and of the TFT orientation relative to the grains. The application of hot carrier stress, with a condition of V{sub GS} = V{sub DS}/2, was determined to induce threshold voltage, subthreshold swing and transconductance degradation for TFTs in thicker polysilicon films and the associated stress-induced increase in the active layer trap density was evaluated. However, this device degradation was drastically reduced for TFTs fabricated in ultra-thin films. Furthermore, the application of the same stress condition to TFTs oriented vertically to the elongated grains resulted ...

British Library Electronic Table of Contents (United Kingdom)

A solar water splitting cell composed of WO3, Polymer Electrolyte Membrane (PEM) and Pt was constructed for producing hydrogen from deionized water in sunlight. Spectral responsivity measurements under various temperatures and bias voltages were conducted for the cell using the Incident Photon to Current Efficiency (IPCE) method. For comparison, a known WO3 Photo Electro Chemical (PEC) cell containing H3PO4 electrolyte, WO3/H3PO4/Pt, was tested using the same test method. The WO3/PEM-H2O/Pt cell showed better Quantum Efficiency (QE) performance compared to that obtained from the cell with the chemical electrolyte. For the first time, spectral responsivity of photo water splitting process without bias power was unveiled in the new WO3 cell, demonstrating the self-sustained photo electrolysi...

British Library Electronic Table of Contents (United Kingdom)

The effect of mean daily air temperature (MDT) on flowering rate (the reciprocal of days to flower) was quantified for 18 species of annual bedding plants. Plants were grown in environmental growth chambers at constant air temperature set points of 5, 7.5, 10, 15, 25, or 30^oC and under an irradiance of 160-180mmolm^-^2s^-^1, with a 16-h photoperiod. Nonlinear mathematical equations were developed to predict the effect of MDT on flowering rate and to estimate the base, optimum, and maximum temperatures (Tmin, Topt, and Tmax), which are the temperatures at which flowering rates are zero (low temperature), maximal, and zero once again (high temperature), respectively. The estimated Tmin varied among species and ranged from 1.1^oC in French marigold (Tagetes patula L.) to 9.9^oC in angelonia ...

British Library Electronic Table of Contents (United Kingdom)

Remote sensing is the most practical method available to managers of fire-prone forests for quantifying and mapping fire impacts. Differenced Normalised Burn Ratio (?NBR) is among the most widely used spectral indices for the mapping of burn severity but is difficult to interpret in terms of fire-related changes in key biophysical attributes and processes. We propose to quantify burn severity as a change in the leaf area index (?LAI) of a stand. LAI is a key biophysical attribute of forests, and is central to understanding their water and carbon cycles. Previous studies have suggested that changes in canopy LAI may be a major contributor to ?NBR and to the composite burn index (CBI) that is frequently used in combination with the NBR to assess burn severity on the ground. We applied remote...

Energy Technology Data Exchange (ETDEWEB)

Properly quantified performance of a solar-thermal cavity receiver must not only account for the energy gains and losses as dictated by the First Law of thermodynamics, but it must also account for the quality of that energy. Energy quality can only be determined from the Second Law. In this paper, an equation developed for the Second-Law efficiency of a cavity receiver is presented as an evolution from the definition of available energy or ''availability'' (occasionally called exergy). The variables required are all either known or readily determined. The importance of considering the Second-Law is emphasized by a comparison of the First- and Second-Law efficiencies around an example of data collected from two receivers that were designed for different purposes, where the attempt was made to demonstrate that a Second-Law approach to quantifying the performance of a solarthermal cavity receiver lends more ...

Energy Technology Data Exchange (ETDEWEB)

Laser-induced phase-separation polymerization of a porous acrylate polymer is used for in-situ fabrication of dialysis membranes inside glass microchannels. A shaped 355 nm laser beam is used to produce a porous polymer membrane with a thickness of about 15 .mu.m, which bonds to the glass microchannel and forms a semi-permeable membrane. Differential permeation through a membrane formed with pentaerythritol triacrylate was observed and quantified by comparing the response of the membrane to fluorescein and fluorescently tagging 200 nm latex microspheres. Differential permeation was observed and quantified by comparing the response to rhodamine 560 and lactalbumin protein in a membrane formed with SPE-methylene bisacrylamide. The porous membranes illustrate the capability for the present technique to integrate sample cleanup into chip-based analysis systems.

British Library Electronic Table of Contents (United Kingdom)

Abstract A method was developed to quantify the effect of scanner instability on functional MRI data by comparing the instability noise to endogenous noise present when scanning a human. The instability noise was computed from agar phantom data collected with two flip angles, allowing for a separation of the instability from the background noise. This method was used on human data collected at four 3 T scanners, allowing the physiological noise level to be extracted from the data. In a -well-operating- scanner, the instability noise is generally less than 10% of physiological noise in white matter and only about 2% of physiological noise in cortex. This indicates that instability in a well-operating scanner adds very little noise to functional MRI results. This new method allows researcher...

Science.gov (United States)

A rotational speed control, tailored to the Sunflower system requirements, was designed and fabricated in breadboard, preprototype, and prototype configurations. These units were subjected to performance and environmental testing which has led to design improvements. Program efforts have yielded hardware capable of meeting all performance requirements and of operating under all the environmental conditions to which the units were exposed. Attractive design changes were identified and, in some cases, completed. These changes involve improvements in circuitry and packaging, the primary objectives of which are to eliminate startup bias batteries and reduce weight. It is recommended that the reported program be extended to implement these improvements. (auth)

Energy Technology Data Exchange (ETDEWEB)

The authors have measured the noise of MOS transistors of the United Technology Microelectronics Center (UTMC) 1.2 [mu]m radiation hardened CMOS P-well process from the weak to moderate inversion region. The noise power spectral densities of both NMOS and PMOS devices were measured from 1 KHz to 50 MHz. The bandwidth was chosen such that the important components of the spectral densities such as the white thermal noise and the 1/f noise could be easily resolved and analyzed in detail. In this paper the effects of different device terminal DC biases and channel geometries on the noise are described.

Energy Technology Data Exchange (ETDEWEB)

This paper presents calculations of the {sup 252}Cf-source-driven noise analysis measurements for subcritical highly enriched uranium metal cylinders using the Monte Carlo code MCNP-DSP. This code directly calculates the noise analysis data from the {sup 252}Cf- source-driven noise analysis method for both neutron and gamma ray detectors. Direct calculation of experimental observables by the Monte Carlo method allows for the benchmarking of the calculational model and the cross sections and for determining the bias in the calculation.

Energy Technology Data Exchange (ETDEWEB)

A robust transmission element for transmitting information between downhole tools, such as sections of drill pipe, in the presence of hostile environmental conditions, such as heat, dirt, rocks, mud, fluids, lubricants, and the like. The transmission element maintains reliable connectivity between transmission elements, thereby providing an uninterrupted flow of information between drill string components. A transmission element is mounted within a recess proximate a mating surface of a downhole drilling component, such as a section of drill pipe. To close gaps present between transmission elements, transmission elements may be biased with a "spring force," urging them closer together.

Energy Technology Data Exchange (ETDEWEB)

Until April 2007 the Major Atmospheric Gamma ray Imaging Cherenkov (MAGIC) telescope used a 300 MSamples/s flash analog-to-digital converter (FADC) system to sample the shaped photomultiplier tube (PMT) signals produced by the captured Cherenkov photons of air showers. Different algorithms to reconstruct the signal from the read-out samples (extractors) have been implemented and are described and compared. Criteria based on the obtained charge and time resolution/bias are defined and used to judge the different extractors, by applying them to calibration, cosmic and pedestal signals. The achievable charge and time resolution have been derived as functions of the number of incident photo-electrons.

Energy Technology Data Exchange (ETDEWEB)

A brief description is presented of the Westinghouse Torsional Dynamic Stabilizer, which was developed primarily as a countermeasure to ''torsional interaction'' subsynchronous resonance. Two such systems were installed and commissioned at the San Juan Generating Station, Waterflow, New Mexico in July, 1980. This paper describes the maintenance procedures and operating experience to date of these two units. The only known instance of operation at the high level bias point of the Stabilizer appears to indicate that the unit helped to dampen a turbine-generator shaft oscillation transient.

Energy Technology Data Exchange (ETDEWEB)

The centroid and envelope dynamics of a high-intensity charged particle beam are investigated as a beam smoothing technique to achieve uniform illumination over a suitably chosen region of the target for applications to ion-beam-driven high energy density physics and heavy ion fusion. The motion of the beam centroid projected onto the target follows a smooth pattern to achieve the desired illumination, for improved stability properties during the beam-target interaction. The centroid dynamics is controlled by an oscillating "wobbler", a set of electrically-biased plates driven by RF voltage. __________________________________________________

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

Anthropogenic sulfate aerosol, together with particles from biomass burning, may significantly reduce the climatic warming due to man-made greenhouse gases. The radiative forcing of aerosol particles is based on their ability to scatter and absorb solar radiation (direct effect), and on their influences on cloud albedos and lifetimes (indirect effect). The direct aerosol effect depends strongly on the size, number and chemical composition of particles, being greatest for particles of 0.1-1 {mu}m in diameter. The indirect aerosol effect is dictated by the number of particles being able to act as cloud condensation nuclei (CCN). For sulfate particles, the minimum CCN size in tropospheric clouds is of the order of 0.05-0.2 {mu}m. To improve aerosol parameterizations in future climate models, it is required that (1) both primary and secondary sources of various particle types will be characterized at a greater accuracy, and (2) the influences of various atmospheric processes on the spatial ...

International Nuclear Information System (INIS)

This paper reports on a Level 1 PRA performed on the Omega West Reactor at Los Alamos National Laboratory. A Master Logic Diagram was used to identify possible initiating events. A chi-square distribution was used to quantify initiating event frequencies given that no initiating events have occurred in 30 years of OWR operation. The PRA results are presented as both probability density function and cumulative distribution function curves.

Energy Technology Data Exchange (ETDEWEB)

We have measured the oxygen positions in LaNiO{sub 3} films to elucidate the coupling between epitaxial strain and oxygen octahedral rotations. The oxygen positions are determined by comparing the measured and calculated intensities of half-order Bragg peaks, arising from the octahedral rotations. Combining ab initio density-functional calculations with these experimental results, we show how strain systematically modifies both bond angles and lengths in this functional perovskite oxide.

Energy Technology Data Exchange (ETDEWEB)

Plantago ovata Forsk - an economically important medicinal plant - was analyzed for trace elements and chlorophyll in a study of the effects of gamma radiation on physiological responses of the seedlings. Proton-induced X-ray emission (PIXE) technique was used to quantify trace elements in unirradiated and gamma-irradiated plants at the seedling stage. The experiments revealed radiation-induced changes in the trace element and chlorophyll concentrations.

UK PubMed Central (United Kingdom)

The alkylation products formed by in vitro treatment of DNA with tritium-labeled 1,3-bis(2-chloroethyl)-1-nitrosourea (³H-BCNU) were identified and quantified. Twelve adducts were resolved...Full Text Available

UK PubMed Central (United Kingdom)

Veterinarians and farmers employing multivalent killed vaccines in lactating dairy cows have reported transient losses in milk production. Few studies have quantified this loss. In this report, effects...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

We analyze large diffusion-limited aggregates and uncover a {ital discrete} scaling invariance in their inner structure, which can be quantified by the introduction of a set of {ital complex} fractal dimensions. We provide a theoretical framework and prediction of their values based on renormalization group theory and a previous wavelet analysis. {copyright} {ital 1996 The American Physical Society.}

International Nuclear Information System (INIS)

The use of natural energy sources and their conversion to secondary forms of energy are a crucial base for the development of our society with its continuous change of requirements due to an increase in population and the broadening of the needs in our modern life. As a consequence the consumption of primary energy resources rose drastically worldwide during the last 5 decades in particular in the industrialized regions such as Europe. Parallel in time the increasing awareness of negative effects of fuel dependent pollution on the environment and the introduction of stringent emission control regulations about 3 decades ago initiated extensive development and retrofit activities resulting in the today applied high level state of the art. As an additional challenge the worldwide debate about the potential effects of the emission of the s.c green house gases on the global climate in particular carbon dioxide from the use of predominantly fossil fuels have initiated in the European Union ...

Science.gov (United States)

The urine test strip is the most common test used to detect ketones in veterinary patients, but it can underestimate the degree of ketonuria and hence, ketonemia. Additionally, adequate urine samples for analysis may be difficult to obtain from dehydrated animals. The standard method used to detect and monitor ketonemia in human medicine is measurement of serum or whole blood beta-hydroxybutyrate (?HOB). A point-of-care (POC) analyzer has been validated for this purpose in humans. This study compared the accuracy of the POC device to an enzymatic reaction laboratory method for measurement of ?HOB in dogs. Although the POC sensor tended to overestimate ?HOB concentrations, there was good correlation (R(2) = 0.96) and good agreement between the 2 methods with a bias +/- precision of 0.0860 +/- 0.3410 mmol/L ?HOB. The POC ?HOB sensor can be useful for assessing ketonemia in dogs. PMID:21119867

British Library Electronic Table of Contents (United Kingdom)

Parthenogenesis-inducing (PI) Wolbachia belong to a class of intracellular symbionts that distort the offspring sex ratio of their hosts toward a female bias. In many PI Wolbachia-infected species sex ratio distortion has reached its ultimate expression-fixation of infection and all-female populations. This is only possible with thelytokous PI symbionts as they provide an alternative form of reproduction and remove the requirement for males and sexual reproduction. Many populations fixed for PI Wolbachia infection have lost the ability to reproduce sexually, even when cured of the infection. We examine one such population in the species Trichogramma pretiosum. Through a series of backcrossing experiments with an uninfected Trichogramma pretiosum population we were able to show that the gen...

Science.gov (United States)

In the last decade, directed evolution has become a routine approach for engineering proteins with novel or altered properties. Concurrently, a trend away from purely 'blind' randomization strategies and towards more 'semi-rational' approaches has also become apparent. In this review, we discuss ways in which structural information and predictive computational tools are playing an increasingly important role in guiding the design of randomized libraries: web servers such as ConSurf-HSSP and SCHEMA allow the prediction of sites to target for producing functional variants, while algorithms such as GLUE, PEDEL and DRIVeR are useful for estimating library completeness and diversity. In addition, we review recent methodological developments that facilitate the construction of unbiased libraries, which are inherently more diverse than biased libraries and therefore more likely to yield improved variants. PMID:16095966

British Library Electronic Table of Contents (United Kingdom)

This work aims to contribute to the understanding of the influence of the ionospheric layer height (ILH) on the thin layer ionospheric model (TLIM) used to retrieve ionospheric information from the GNSS observations. Particular attention is paid to the errors caused on the estimation of the vertical total electron content (vTEC) and the GNSS satellites and receivers inter-frequency biases (IFB), by the use of an inappropriate ILH. The work relies upon numerical simulations performed with an empirical model of the Earth?s ionosphere: the model is used to create realistic but controlled ionospheric scenarios and the errors are evaluated after recovering those scenarios with the TLIM. The error assessment is performed in the Central and the northern part of the South American continents, a re...

Science.gov (United States)

This study examined the psychometric properties of the Anti-fat Attitudes Scale (AFAS), a 5-item instrument developed by the authors to measure negative attitudes toward overweight individuals. A total of 4 studies were conducted among Canadian adolescents (n = 1,452) and university students (n = 424). Results suggested that the AFAS possessed a unidimensional factor structure and satisfactory reliability for both men and women. As predicted, men obtained higher scores than women on the AFAS, and antifat attitudes were positively associated with authoritarianism, homonegativity, and political conservatism. Participants who were overweight had lower scores on the AFAS than participants who were thin or average weight. Responses on the AFAS did not appear to be contaminated by social desirability bias. PMID:10457760

International Nuclear Information System (INIS)

We report on the improvement of Critical Dimension (CD) linearity on a photomask by applying the concept of process proximity correction to a laser lithographic process used for fabrication of photomasks. Rule-based Laser Process proximity Correction (LPC) was performed using an automated optical proximity correction tool and we obtained dramatic improvement of CD linearity on a photomask. A study on model-based LPC was executed using a two-Gaussian kernel function and we extracted model parameters for the laser lithographic process by fitting the model-predicted CD linearity data with measured ones. Model-predicted bias values of isolated space (I/S), Arrayed Contact (A/C) and Isolated Contact (I/C) were in good agreement with those obtained by the nonlinear curve-fitting method used for the rule-based LPC.

British Library Electronic Table of Contents (United Kingdom)

In this paper we present the results of time series analysis for a coal mining region based on partial unmixing. We test the method also known as mixture tuned matched filtering on an eight image Landsat 5 TM and Landsat 7 ETM+ time series covering the period from 1987 to 2003. Common change detection methods often include the comparison of two interactively generated classification results, such as derived from Maximum Likelihood classification. These approaches often yield highly accurate results. However, disadvantages include a strong analyst bias and hardly repeatable results. For a quantitative monitoring of a single surface class' development over time they are often not recommendable. Our goal was to test an unbiased quantitative way to assess the development of coal surfaces, such...

CERN Document Server

The possibility of radio galaxies being random sample of otherwise normal elliptical galaxies is tested. Starting with the observed optical luminosity functions for elliptical galaxies, it is shown that the probability of an elliptical forming a radio source is a continuous, increasing function of optical luminosity, precisely proportional to square of the optical luminosity of the galaxy. Once the probability function is fixed, the luminosity function of normal elliptical galaxies is used as input for Monte Carlo simulations that reproduce the distribution of radio galaxies in the radio-optical luminosity plane. Our results show that radio galaxies are luminosity biased, but otherwise random sample of elliptical galaxies. This unified view of radio and non-radio ellipticals also explains the well known difference of 0.5 mag in average optical luminosity between FRI and FRII radio galaxies as a simple selection effect. Specifically, FRII appear preferentially in ...

International Nuclear Information System (INIS)

An effective method of enhancing charge injection and electroluminescence efficiency of polymer-based light emitting diode is introduced. Spin-coated films of poly (N-vinylcarbazole) blended with electron-transport material (Bu-PBD), laser dye (Coumarin6), and the typical supporting electrolyte (tetraethylammonium perchlorate; TEAP) were examined and it was found that the injection current and luminance of the light emitting diode doped with TEAP were enhanced dramatically after heat-treatment at 80 deg. C and appropriate biasing in an external electric field of 1.5x10"8 V/m at this temperature. The thermally stimulated current (TSC) was also measured to investigate the relaxation process of ionic space charges in the films. The relaxation times of ionic polarization were found to be related to the cation size of the electrolyte. And the relaxation time becomes long enough by the use of TEAP doping.

CERN Document Server

In this paper we develop an analytical framework for the study of electrochemical impedance of mixed ionic and electronic conductors (MIEC). The framework is based on first-principles and it features the coupling of electrochemical reactions, surface transport and bulk transport processes. We utilize this work to analyze two dimensional systems relevant for fuel cell science via finite element method (FEM). Alternate current Impedance Spectroscopy (IS) of a ceria symmetric cell is simulated near equilibrium condition (zero bias) for a wide array of working conditions including variations of temperature and $H_2$ partial pressure on a two dimensional fuel cell sample with patterned metal electrodes. The model shows agreement of IS curves with the experimental literature with the relative error on the impedance being consistently below 2%. Important two-dimensional effects such the effects of thickness decrease and the influence of variable electronic and ionic ...

Science.gov (United States)

The authors have studied (Al{sub x}Ga{sub 1{minus}x}){sub 0.5}In{sub 0.5}P doped with tellurium using deep level transient spectroscopy and associated electrical measurements. Several defect states are observed in the upper half of the band gap, that are believed to be intrinsic to the alloy system as well as related to the tellurium donors. Defects observed at measurement temperatures above 390 K exhibit a hysteretic behavior. The observed spectra depend on the biasing conditions applied to the Schottky diode during cooling. The hysteretic behavior suggests the existence of different defect configurations, which can be accessed under conditions of high temperatures and electrical stress, but remain stable below 300 K.

International Nuclear Information System (INIS)

We report on the fabrication of nanomechanical devices for shuttling of electrons from one electrode to another. Each device consists of a 20 nm diameter gold nanoparticle embedded within the gap between two gold electrodes. In two different kinds of shuttle-junctions the nanoparticle is attached to the electrodes through either (i) a single layer of 1,8-octanedithiol or (ii) a multilayer of 1-octanethiol molecules. The thiol layers play the role of 'damped springs', such that when a sufficient voltage bias is applied to the junction, the nanoparticle is expected to start oscillating and thereby transferring electrons from one electrode to the other. For both kinds of shuttle-junctions we observed an abrupt increase in the transmitted current above a threshold voltage, which can be attributed to a transition from the stationary to the oscillating regime. The threshold voltage was found to be lower for single-layer shuttle-junctions.

Energy Technology Data Exchange (ETDEWEB)

Incomplete convergence in numerical simulation such as computational physics simulations and/or Monte Carlo simulations can enter into the calculation of the objective function in an optimization problem, producing noise, bias, and topo- graphical inaccuracy in the objective function. These affect accuracy and convergence rate in the optimization problem. This paper is concerned with global searching of a diverse parameter space, graduating to accelerated local convergence to a (hopefully) global optimum, in a framework that acknowledges convergence uncertainty and manages model resolu- tion to efficiently reduce uncertainty in the final optimum. In its own right, the global-to-local optimization engine employed here (devised for noise tolerance) performs better than other classical and contemporary optimization approaches tried individually and in combination on the "industrial" test problem to be presented.

British Library Electronic Table of Contents (United Kingdom)

Climate variability greatly affects animals through direct and indirect effects. Animals with slow reproductive adaptation to ecological changes such as large mammals are likely to have evolved mechanisms to anticipate early such impacts of climate variability on the environment. One of the adaptive mechanisms between reproductive costs and benefits in mammals affects parental investment through biases in sex ratio. Deer might be likely to show an early detection of climate variability because conception takes place in early autumn, but the main raising cost in deer concerns lactation, which takes place at the end of the following spring. The aim of this paper is to assess whether there is a relationship between global indices of climate variability such as El Ni?o-Southern Oscillation (EN...

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...

Energy Technology Data Exchange (ETDEWEB)

The effect of asymmetry tilt angle ion implantation on polysilicon thin-film transistors (TFTs) device characteristics are investigated. This asymmetric source/drain (S/D) TFTs structure exhibits low leakage current and suppressed kink effect due to the relief of higher electric field near the drain junction side. It is shown that the optimal implantation tilt angle is 30 deg. in our annealing condition. And the anomalous off-state current is more than two orders of magnitude lower than that of the conventional TFTs. By well controlled the LDD region, this structure can act as a conventional structure in the on-state and the turn-on current will not be degraded. Besides, the device under severe hot carrier bias stress shows better hot carrier endurance.

Energy Technology Data Exchange (ETDEWEB)

The Atmospheric Release Advisory Capability (ARAC) at the Lawrence Livermore National Laboratory uses the U.S. Navy's Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS) to supply high-resolution wind data for use in its real-time dispersion modeling system. ARAC has used COAMPS products to support several events and exercises, and COAMPS forecasts appear accurate, based on qualitative examination. Recently ARAC has developed a quantitative verification system which calculates COAMPS error and bias statistics, comparing COAMPS forecasts of various lengths with observational data. This paper shows how this system has been used to guide ARAC operators, who need an estimate of the likely behavior of COAMPS forecasts of various lengths in different regions, seasons, and weather patterns.

British Library Electronic Table of Contents (United Kingdom)

What is the effect of ambiguity aversion on trade? Although in a Bewley?s model, ambiguity aversion always leads to less trade; in other models, this is not always true. However, we show that if the endowments are unambiguous, then more ambiguity aversion implies less trade for a very general class of preferences. The reduction in trade caused by ambiguity aversion can be as severe as to lead to no trade. In an economy with MEU decision makers, we show that if the aggregate endowment is unanimously unambiguous, then every Pareto optima allocation is also unambiguous. We also characterize the situation in which every unanimously unambiguous allocation is Pareto optimal. Finally, we show how our results can be used to explain the home-bias effect. As a useful result for our methods, we also ...

International Nuclear Information System (INIS)

In view of no satisfactory mathematical model is presently available for the dose-response curve of immunoradiometric assay, a three parameter model based on single binding site mass action law has been derived. A curve fitting method based on similar principle of linear robust regression was designed and a software was prepared for use on IBM personal computers. Experiments revealed that the model is applicable to a variety of IRMA systems as well as to time-resolved immunofluorometric assay of hAFP. When there was outlier(s) of the calibration curve, the average bias of unknown samples obtained with this method is significantly smaller than methods using four parameter logistic model or four parameter single site mass action model.

Energy Technology Data Exchange (ETDEWEB)

There is currently considerable interest in identifying and quantifying the effects of welding procedure parameters and steel composition factors on the risk of cracking in pipeline girth welds that may be experienced during winter construction. Although low ambient temperatures, that may be experienced during winter construction, are generally assumed to increase the risk of cracking there has been little work to quantify the effects and to suggest how welding procedures should be modified for winter conditions. The present work was undertaken to calculate the effects of changes in welding parameters on the thermal cycle and the diffusion of hydrogen for a typical pipeline girth weld. A simple analytical method and the finite element method (FEM) were used. Both methods gave similar results but the simple method was very sensitive to the value of heat transfer coefficient. The results showed that the relation between the hydrogen diffusion ...

Energy Technology Data Exchange (ETDEWEB)

Properly quantified performance of a solar-thermal cavity receiver must not only account for the energy gains and losses as dictated by the First Law of thermodynamics, but it must also account for the quality of that energy. However, energy quality can only be determined from the Second Law. In this paper an equation for the Second-Law efficiency of a cavity receiver is derived from the definition of available energy or availability (occassionally called exergy), which is a thermodynamic property that measures the maximum amount of work obtainable when a system is allowed to come into unrestrained equilibrium with the surrounding environment. The fundamental concepts of the entropy and availability of radiation are explored from which a convenient relationship among the reflected cone half angle, the insolation, and the concentrator geometric characteristics is developed as part of the derivation of the Second-Law efficiency. A comparison is made between First- ...

Energy Technology Data Exchange (ETDEWEB)

JAERI has been performing transient core thermal-hydraulic test program. In the program, authors performed BWR/ABWR DBE simulation tests with a test facility, which can simulate BWR/ABWR transients. The test facility has a 4 x 4 bundle core simulator with 15-rod heaters and one non-heated rod. Through the tests, authors quantified the thermal safety margin for core cooling. In order to quantify the thermal safety margin, authors collected experimental data on post-CHF. The data are essential for the evaluation of clad temperature transient when core heat-up occurs during DBEs. In comparison with previous post-CHF tests, present experiments were performed in much wider experimental condition, covering high clad temperature, low to high pressure and low to high mass flux. Further, data at wider elevation (lower to higher elevation of core) were obtained in the present experiments, which make possible to discuss the effect of axial position on ...

International Nuclear Information System (INIS)

This work concerns the development of a methodology the objective of which is to characterize and diagnose two-phase flow regime transitions. The approach is based on the fundamental assumption that a transition flow is less stationary than a flow with an established regime. During the first time, the efforts focused on: (1) the design and construction of an experimental loop, allowing to reproduce the main horizontal two-phase flow patterns, in a stable and controlled way; (2) the design and construction of an electrical impedance probe, providing an imaged information of the spatial phase distribution in the pipe; and (3) the systematic study of the joint time-frequency and time-scale analysis methods, which permitted to define an adequate parameter quantifying the unstationarity degree. During the second time, in order to verify the fundamental assumption, a series of experiments were conducted, the objective of which was to demonstrate the correlation between ...

Energy Technology Data Exchange (ETDEWEB)

In rare instances, carbon monoxide (CO) levels in houses can reach dangerously high concentrations, causing adverse health effects ranging from mild headaches to, under extreme conditions, death. Hundreds of fatal accidental carbon monoxide poisonings occur each year primarily due to the indoor operation of motor vehicles, the indoor use of charcoal for cooking, the operation of malfunctioning vented and unvented combustion appliances, and the misuse combustion appliances. Because there is a lack of simple, inexpensive, and accurate field sampling instrumentation, it is difficult for gas utilities and researchers to conduct field research studies designed to quantify the concentrations of CO in residences. Determining the concentration of CO in residences is the first step towards identifying the high risk appliances and high-CO environments which pose health risks. Thus, there exists an urgent need to develop and field-validate a ...

Energy Technology Data Exchange (ETDEWEB)

Passage of neon gas through activated charcoal is planned to be the primary method of removing impurities from the liquid neon scintillator in the CLEAN experiment. In order to quantify this technique, the breakout curves for hydrogen, nitrogen, argon and krypton impurities in neon-saturated activated charcoal were measured. Adsorption coefficients and the number of theoretical stages were measured for hydrogen in the temperature range between 300 and 80 K, nitrogen between 300 and 200 K, and argon between 300 and 190 K. The adsorption coefficient for krypton was measured at 300 K.

Energy Technology Data Exchange (ETDEWEB)

Although studied for many years the nature of the light scalar mesons remains controversial. Here we shall present a method, applicable for s-wave states located close to a threshold, that allows one to quantify the molecular part of a given state. When applied to the f{sub 0}(980) a dominance of the molecular component is found. In the second part, we show that requirements of field-theoretic consistency and chiral symmetry, when applied to the scattering of light pseudo-scalars, naturally lead to the appearance of dynamical poles in the scalar sector. A program is proposed on how to further investigate experimentally the mixing between these dynamical states and possible genuine quark states. (orig.)

International Nuclear Information System (INIS)

We have synthesized ozone by irradiating thin solid films of oxygen and oxygen-water mixtures with 100 keV protons, motivated by recent reports of condensed O_3 on icy satellites in the outer Solar system. We measured the depth of the Hartley absorption band in the ultraviolet by reflectance spectroscopy and used it to quantify the column density of ozone. We analyzed the results using a three-component (O, O_2 and O_3) model that successfully explains the fluence dependence of ozone production.

Science.gov (United States)

Investigations were conducted at Los Alamos National Laboratory to quantify the extent of migration of depleted uranium away from firing sites. Extensive sampling of air particles, soil, sediment, and water was conducted to establish the magnitude of uranium contamination throughout one watershed. The uranium source term was estimated, and mass balance calculations were performed to compare the percentage of migrated uranium with original expenditures. Mass balance calculations can be powerful in identification of the extent of waste migration and used as an aid in planning future waste investigations.

Energy Technology Data Exchange (ETDEWEB)

The Systems Design Study (SDS) identified technologies available for the remediation of low-level and transuranic waste stored at the Radioactive Waste Management Complex`s Subsurface Disposal Area at the Idaho National Engineering Laboratory. The SDS study intentionally omitted the costs of transportation and disposal of the processed waste and the cost of decommissioning the processing facility. This report provides a follow-on analysis of the SDS to explore the basis for life-cycle cost segments of transportation, disposal, and facility decommissioning; to determine the sensitivity of the cost segments; and to quantify the life-cycle costs of the 10 ex situ concepts of the Systems Design Study.

International Nuclear Information System (INIS)

The objectives of the project were to develop operational techniques for promoting contaminant hideout return from tube support crevices and to identify the effect of chemical inhibitor application on corrodent transport. The implementation of routine procedures for promoting the return of sequestered corrodents could retard the progression of denting or other corrosion processes and improve steam generator availability. Tests also quantified the effect of inhibitor application on crevice hideout and hideout return processes, with the intention of developing a better understanding of the inhibition mechanism. By carefully monitoring the hideout and hideout return inventories, the program also has provided the opportunity to study steam generator concentration processes in general.

Energy Technology Data Exchange (ETDEWEB)

Two mesoscopic SQUID rings which are far from each other are considered. A source of two-mode nonclassical microwaves irradiates the two rings with correlated photons. The Josephson currents are in this case quantum mechanical operators, and their expectation values with respect to the density matrix of the microwaves yield the experimentally observed currents. Classically correlated (separable) and quantum mechanically correlated (entangled) microwaves are considered, and their effect on the Josephson currents is quantified. Results for two different examples that involve microwaves in number states and coherent states are derived. It is shown that the quantum statistics of the tunnelling electron pairs through the Josephson junctions in the two rings are correlated.

CERN Document Server

This report describes studies performed in the framework of the Collimation Task Force organized to support the work of the second International Linear Collider Technical Review Committee. The post-linac beam-collimation systems in the TESLA, JLC/NLC and CLIC linear-collider designs are compared using the same computer code under the same assumptions. Their performance is quantified in terms of beam-halo and synchrotron-radiation collimation efficiency. The performance of the current designs varies across projects, and does not always meet the original design goals. But these comparisons suggest that achieving the required performance in a future linear collider is feasible.

International Nuclear Information System (INIS)

The paper discusses the Intergovernment Panel on Climate Change (IPCC) report on Aviation and the Global Atmosphere (published in 1999). It was considered necessary to treat air transport on its own since aircraft are unique in delivering emissions into the upper atmosphere rather than at ground level. The study was commissioned at the request of the International Civil Aviation Organisation and the Montreal Protocol. More than 300 experts contributed and the report has quantified the effect of aviation on the atmosphere on a world wide basis and highlighted areas where improved data are required. (UK)

Wastenet

...it only highlights the different feedstocks used in the production of fiber-based packaging materials or fossil-fuel ones; what about the energy required to convert ...feedstock, is unacceptable in trying to quantify the overall burden a specific packaging material has on the environment. As an aside, the point ... Consequentially, it is difficult to speculate on how much packaging material a company diverts from the landfill by switching from one material to another ...without specifying what geographical region said packaging material resides in. In addition, there is a lot of interest in diverting PET thermoforms from ...

Energy Technology Data Exchange (ETDEWEB)

This paper describes a novel Fourier transform infrared (FTIR) spectroscopic method that can be used to rapidly screen soil samples from potentially hazardous waste sites. Samples are heated in a thermal desorption unit and the resultant vapors are collected and analyzed in a long-path gas cell mounted in a FTIR. Laboratory analysis of a soil sample by FTIR takes approximately 10 minutes. This method has been developed to identify and quantify microgram concentrations of explosives in soil samples and is directly applicable to the detection of selected volatile organics, semivolatile organics, and pesticides.

CERN Document Server

We have implemented a virtual Young's double slit experiment for hard X-ray photons with micro-fabricated bi-prisms. We observe fringe patterns with a scintillator, and quantify interferograms by detecting X-ray fluorescence from a scanned 30nm Cr metal film. The observed intensities are best modeled with a near-field, Fresnel analysis. The maximum fringe number in the overlap region is proportional to the ratio of real to imaginary parts refractive index of the prism material. The horizontal and vertical transverse coherence lengths at beamline APS 8-ID are measured.

Energy Technology Data Exchange (ETDEWEB)

The regenerator of Stirling cycle machines has an relatively unknown potential for thermal shorting, because the thermal flow path within the solid of a randomly stacked wire mesh, which is defined by its 'connectivity', is unknown. Earlier publications have shown two principles of experimental techniques to quantify connectivity. One quantifies connectivity as a function of axial pressure using the electric current analogy, the other measures connectivity via the temperature gradients along a regenerator and a series-connected reference body of known conductivity. Both papers offer preliminary results of reduced usefulness related to the testing method or setup. This contribution describes a new setup and its technique, which results from the practical knowledge and experience of the first two attempts, and aims for an improved determination of connectivity of the original representative Stirling regenerators with and without ...

International Nuclear Information System (INIS)

We derive improved versions of the relations between supermassive black hole mass (M _B_H) and host-galaxy bulge velocity dispersion (#sigma#) and luminosity (L; the M-#sigma# and M-L relations), based on 49 M _B_H measurements and 19 upper limits. Particular attention is paid to recovery of the intrinsic scatter (#epsilon#_0) in both relations. We find log(M _B_H/M _s_u_n) = #alpha# + #beta#log(#sigma#/200 km s"-"1) with (#alpha#, #beta#, #epsilon#_0) = (8.12 #+-# 0.08, 4.24 #+-# 0.41, 0.44 #+-# 0.06) for all galaxies and (#alpha#, #beta#, #epsilon#_0) = (8.23 #+-# 0.08, 3.96 #+-# 0.42, 0.31 #+-# 0.06) for ellipticals. The results for ellipticals are consistent with previous studies, but the intrinsic scatter recovered for spirals is significantly larger. The scatter inferred reinforces the need for its consideration when calculating local black hole mass function based on the M-#sigma# relation, and further implies that there may be substantial selection bias in ...

Energy Technology Data Exchange (ETDEWEB)

This report describes the experimental researches on the polarization Characteristics of symmetric GaAs-GaAlAsP double heterojunction lasers, and analyses the mode-competition processes of these lasers. The experiments showed that semiconductor laser is emitted spontaneously and does not indicate optical polarization characteristic when it is biased under the threshold current. When it is biased above the threshold current, the laser for thin active layer of d = 0.15approx.0.40 ..mu..m is generally observed only in fundamental order mode, and TE mode polarization is predominant. At this time, polarization selection is dependent on Fabry-Perot cavity facet (cleaved face) mode reflectivity R/sub 0/. But TM mode is saturated at the threshold, the current applied to the laser above the threshold is used to enhance the TE polarization when the active thickness d is larger than 0.4 ..mu..m, the competition between TE and TM mode, fundamental order an ...

Energy Technology Data Exchange (ETDEWEB)

We have observed resonant changes in the current-voltage characteristics of miniband semiconductor superlattices when the Bloch frequency is resonant with a terahertz field and its harmonics: the inverse Bloch oscillator effect. The resonant feature consists of a peak in the current which grows with increasing laser intensity accompanied by a decrease of the current at the low bias side. The peak position moves linearly with the laser frequency. When the intensity is increased further the first peak starts to decrease and a second peak at about twice the voltage of the first peak is observed due to a two photon resonance. At the highest intensities we observe up to a four photon resonance. A superlattice is expected to show negative differential conductance due to the strong nonparabolicity of the miniband. In this situation the carriers should undergo Bloch oscillations with a frequency {omega}{sub B} = eEd/h. Transient Bloch oscillations of photo excited carriers ...

Energy Technology Data Exchange (ETDEWEB)

We have grown ferroelectric Pb{sub 0.92}La{sub 0.08}Zr{sub 0.52}Ti{sub 0.48}O{sub 3} (PLZT) films on platinized silicon and LaNiO{sub 3}-buffered nickel substrates by chemical solution deposition using a sol-gel process based on acetic acid chemistry. The following measurements were obtained under zero-bias field: relative permittivity of {approx}960 and dielectric loss of {approx}0.04 on the PLZT film grown on Pt/Si substrates, and relative permittivity of {approx}820 and dielectric loss of {approx}0.06 on the PLZT film grown on LNO-buffered Ni substrates. In addition, a relative permittivity of 125 and dielectric loss of 0.02 were measured at room temperature under a high bias field of 1 x 10{sup 6} V/cm on PLZT deposited on LNO-buffered nickel substrate. Furthermore, a steady-state leakage current density of {approx}8.1 x 10{sup -9} A/cm{sup 2} and mean breakdown field strength of 1.7 x 10{sup 6} V/cm were measured at room temperature. ...

Energy Technology Data Exchange (ETDEWEB)

Subcritical experiments using californium source-driven noise analysis (CSDNA) and Feynman variance-to-mean methods were performed with an alpha-phase plutonium sphere reflected by nickel shells, up to a maximum thickness of 7.62 cm. Both methods provide means of determining the subcritical multiplication of a system containing nuclear material. A benchmark analysis of the experiments was performed for inclusion in the 2010 edition of the International Handbook of Evaluated Criticality Safety Benchmark Experiments. Benchmark models have been developed that represent these subcritical experiments. An analysis of the computed eigenvalues and the uncertainty in the experiment and methods was performed. The eigenvalues computed using the CSDNA method were very close to those calculated using MCNP5; however, computed eigenvalues are used in the analysis of the CSDNA method. Independent calculations using KENO-VI provided similar eigenvalues to those determined using the CSDNA method and ...

CERN Document Server

We present a method for optimising experimental cuts in order to place the strongest constraints (upper limits) on theoretical signal models. The method relies only on signal and background expectations derived from Monte-Carlo simulations, so no bias is introduced by looking at actual data, for instance by setting a limit based on expected signal above the ``last remaining data event.'' After discussing the concept of the ``average upper limit,'' based on the expectation from an ensemble of repeated experiments with no true signal, we show how the best model rejection potential is achieved by optimising the cuts to minimise the ratio of this ``average upper limit'' to the expected signal from the model. As an example, we use this technique to determine the limit sensitivity of kilometre scale neutrino detectors to extra-terrestrial neutrino fluxes from a variety of models, e.g. active galaxies and gamma-ray bursts. We suggest that these model rejection potential ...

CERN Document Server

Observations of redshift-space distortions in spectroscopic galaxy surveys offer an attractive method for measuring the build-up of cosmological structure, which depends both on the expansion rate of the Universe and our theory of gravity. Galaxies occupy dark matter halos, whose redshift space clustering has a complex dependence on bias that cannot be inferred from the behavior of matter. We identify two distinct corrections on quasilinear scales (~ 30-80 Mpc/h): the non-linear mapping between real and redshift space positions, and the non-linear suppression of power in the velocity divergence field. We model the first non-perturbatively using the scale-dependent Gaussian streaming model, which we show is accurate at the 10 (s>25) Mpc/h for the monopole (quadrupole) halo correlation functions. We use perturbation theory to predict the real space pairwise halo velocity statistics. Our fully analytic model is accurate at the 2 per cent level only on scales s > ...

Science.gov (United States)

In this study, the complete sequence of the mitochondrial DNA (mtDNA) of Atelura formicaria (Hexapoda: Zygentoma) is described. The molecule is 15.205 bp in length and it is the third complete mt genome sequenced from the Zygentoma. The genome organization conforms with the putative ancestral insect gene arrangement. All protein coding genes use standard initiation codons (methionine and isoleucine). The exception is nad4 that starts with GTG, a codon used for this purpose in other insect species. A peculiar strand skew bias is observed, given that the PCGs encoded on the J-strand contain more thymines than adenines and more cytosines than guanines. This trend in nucleotide composition has been observed also in the "firebrat" Thermobia domestica (Zygentoma, Lepismatidae), but differs from that of the majority of hexapod species, including Tricholepidion gertschi (Zygentoma, Lepidotrichidae), where adenines and cytosines outnumber thymines and guanines. The presence ...

International Nuclear Information System (INIS)

By using a plasma nitriding procedure at the PUPR Mirror Cusp Plasma machine, surface hardness is increased in 302/304-type stainless steel samples by exposing them to high-ion-density plasma at high vacuum. This method successfully dopes the surface of the material with strengthening nitrogen ions, without the use of chemical procedures that sacrifice the resistance to corrosion of the given material. A 500 V negative bias is placed on the sample exposed to the nitrogen plasma, where high-energy ions are therefore attracted and immersed into the metallic matrix microns into the surface of the stainless steel. This potential maintains a constant surface temperature at approximately 800 deg. C. The plasma parameters including ion density and plasma temperature were diagnosed using single Langmuir probes. The stainless steel samples were then tested using scanning electron microscopy (SEM), and Vickers micro-hardness testing to determine the increment in the surface ...

Energy Technology Data Exchange (ETDEWEB)

A portable barrier strip having retractable tire-puncture spikes for puncturing a vehicle tire. The tire-puncture spikes have an armed position for puncturing a tire and a retracted position for not puncturing a tire. The strip comprises a plurality of barrier blocks having the tire-puncture spikes removably disposed in a shaft that is rotatably disposed in each barrier block. The plurality of barrier blocks hare hingedly interconnected by complementary hinges integrally formed into the side of each barrier block which allow the strip to be rolled for easy storage and retrieval, but which prevent irregular or back bending of the strip. The shafts of adjacent barrier blocks are pivotally interconnected via a double hinged universal joint to accommodate irregularities in a roadway surface and to transmit torsional motion of the shaft from block to block. A single flexshaft cable is connected to the shaft of an end block to allow a user to selectively cause the shafts of a plurality of ...

Energy Technology Data Exchange (ETDEWEB)

Experiments were completed to study intermittent coal-water slurry (CWS) fuel sprays injected from an electronically-controlled accumulator injector system. A new synchronization technique was developed using the light extinction signal as a triggering source for the data taking initiation with a laser diffraction particle analyzing (LDPA) technique. This technique allowed measurement of SMDs near the spray tip where the light extinction was low and the data were free from the multiscattering bias. Coal-water slurry fuel with 50% coal loading in mass containing 5 {mu}m mass median diameter coal particulates was considered. A correlation of the SMD with the injection conditions was determined which should show a satisfactory agreement with the measured SMD data. The spray SMD showed an increase with the distance of the axial measurement location and with the ambient gas density, and showed a decrease with increasing injection pressure.

CERN Document Server

We test the hypothesis that radio galaxies are a random subset of otherwise normal elliptical galaxies. Starting with the observed optical luminosity functions for elliptical galaxies, we show that the probability of an elliptical forming a radio source is a continuous, increasing function of optical luminosity, proportional to L squared. With this probability function and the luminosity function of normal elliptical galaxies as input to Monte Carlo simulations, we reproduce the observed distribution of radio galaxies in the radio-optical luminosity plane. Our results show that radio galaxies are a luminosity-biased but otherwise random sample of elliptical galaxies. This unified view of radio-loud and radio-quiet ellipticals also explains the well known difference of ~0.5 mag in average optical luminosity between FRI and FRII radio galaxies as a simple selection effect. Specifically, FRII appear preferentially in smaller galaxies because both radio and optical ...

Energy Technology Data Exchange (ETDEWEB)

One of the main goals in the determination of three-dimensional macromolecular structures from electron microscope images of individual molecules and complexes (single particles) is a sufficiently high spatial resolution, about 4 A, at which the interpretation with an atomic model becomes possible. To reach high resolution, an iterative refinement procedure using an expectation maximization algorithm is often used that leads to a more accurate alignment of the positional and orientational parameters for each particle. We show here the results of refinement algorithms that use a phase residual, a linear correlation coefficient, or a weighted correlation coefficient to align individual particles. The algorithms were applied to computer-generated data sets that contained projections from model structures, as well as noise. The algorithms show different degrees of over-fitting, especially at high resolution where the signal is weak. We demonstrate that the degree of over-fitting is reduced ...

CERN Document Server

Two headed motor proteins, such as kinesin and dynein, hidrolyze environmental ATP in order to propel unidirectionally along cytoskeletal filaments such as microtubules. In the case of kinesin, protein heads bind primarily on the alpha tubulin site of asymmetric alpha-beta 8nm-long tubulin dimers that constitute the microtubular protofilaments. Kinesin dimers overcome local binding forces up to 5pN and are known to move on protofilaments with ATP concentration-dependent speeds while hydrolizing on average one ATP molecule per 8nm step. The salient features of protein trajectories are the distinct abrupt usually 8nm-long steps from one tubulin dimer to the next interlaced with long quiescent binding periods at a tubulin site. Discrete walks of this type are characterized by substantially reduced variances compared to pure biased random walks, and as a result rule out flashing-type ratchet models as possible mechanisms for motor movement. On the other hand, simple ...

CERN Document Server

NGC 1407 is the central elliptical in a nearby evolved galaxy group apparently destined to become a cluster core. We use the kinematics of globular clusters to probe the dynamics and mass profile of the group's center, out to 60 kpc (~10 R_eff) -- the most extended data set to date around an early-type galaxy. This sample consists of 172 GC velocities, most of them newly obtained using Keck/DEIMOS, with a few additional objects identified as DGTOs or as IGCs. We find weak rotation in the GC system's outer parts, with the metal-poor and metal-rich GCs misaligned. The RMS velocity profile declines rapidly to a radius of ~20 kpc, and then becomes flat or rising to ~60 kpc. There is evidence that the GC orbits have a tangential bias that is strongest for the metal-poor GCs -- possibly contradicting theoretical expectations. We construct cosmologically-motivated galaxy+dark halo dynamical models and infer a mass within 60 kpc of ~3x10^12 M_Sun, extrapolating to a virial ...

Science.gov (United States)

Sperm competition occurs when a female copulates with two or more males and the sperm of those males compete within the female's reproductive tract to fertilize her eggs. The frequent occurrence of sperm competition has forced males of many species to develop different strategies to overcome the sperm of competing males. A prevalent strategy is for males to increase their sperm investment (total number of sperm allocated by a male to a particular female) after detecting a risk of sperm competition. It has been shown that the proportion of sperm that one male contributes to the sperm pool of a female is correlated with the proportion of offspring sired by that male. Therefore, by increasing his sperm investment a male may bias a potential sperm competition in his favour. Here we show that male meadow voles, Microtus pennsylvanicus, increase their sperm investment when they mate in the presence of another male's odours. Such an increase in sperm investment does not ...

British Library Electronic Table of Contents (United Kingdom)

A parameterized surface wave-induced vertical mixing (B"v) is incorporated into the Modular Ocean Model version 4 (MOM4). A comparison of the two numerical experiments with and without B"v shows that B"v can significantly improve the upper-ocean (20-100m) simulation in summer. The simulated upper-ocean temperature errors are reduced in summer due to the surface wave-induced vertical diffusive heat flux. The non-breaking-wave-induced vertical mixing can increase the probability of the simulated SST biases between -1^oC and 1^oC from 64% to 76% in the Southern Hemisphere (60^oS-10^oS) in January, and from 66% to 75% in the Northern Hemisphere (10^oN-60^oN) in July. The averaged mixed layer depth (MLD) simulated by the MOM4 without B"v is 14.4m shallower than the observations in 10^oS-60^oS i...

Energy Technology Data Exchange (ETDEWEB)

The authors apply the nonlinear WENO (Weighted Essentially Nonoscillatory) scheme to the spatial discretization of the Boltzmann Transport Equation modeling linear particle transport. The method is a finite volume scheme which ensures not only conservation, but also provides for a more natural handling of boundary conditions, material properties and source terms, as well as an easier parallel implementation and post processing. It is nonlinear in the sense that the stencil depends on the solution at each time step or iteration level. By biasing the gradient calculation towards the stencil with smaller derivatives, the scheme eliminates the Gibb's phenomenon with oscillations of size O(1) and reduces them to O(h{sup r}), where h is the mesh size and r is the order of accuracy. The current implementation is three-dimensional, generalized for unequally spaced meshes, fully parallelized, and up to fifth order accurate (WENO5) in space. For unsteady problems, ...

Science.gov (United States)

We report on studies of field-effect transistor (FET) and transparent thin-film transistor (TFT) devices based on lightly Ta-doped SnO2 nano-wires. The nanowire-based devices exhibit uniform characteristics with average field-effect mobilities exceeding 100 cm2/V x s. Prototype nano-wire-based TFT (NW-TFT) devices on glass substrates showed excellent optical transparency and transistor performance in terms of transconductance, bias voltage range, and on/off ratio. High on-currents and field-effect mobilities were obtained from the NW-TFT devices even at low nanowire coverage. The SnO2 nanowire-based TFT approach offers a number of desirable properties such as low growth cost, high electron mobility, and optical transparency and low operation voltage, and may lead to large-scale applications of transparent electronics on diverse substrates. PMID:17595151

International Nuclear Information System (INIS)

The application of robotics for repair, refurbishing or dismantling of nuclear installations implies eventually severe radiation resistance requirements on embarked components and subsystems. This is particularly critical when optical sensing is considered. Optoelectronic components and optical fibers are indeed quite sensitive to radiation, and without special design are rapidly out-of-operation in such an environment. This paper reports the results of a series of #gamma# irradiation experiments on such devices, and identify their behavior under radiation. Test results show that carefully selected optical fibers can keep their radiation induced attenuation lower than 0.3 dB/m even up to a total dose of 10 MGy. Temperature annealing can even lower this attenuation down to 0.1 dB/m. On the other hand, commercially available light emitting diodes and photodiodes present attenuations figures up to 15 dB, even after a gamma irradiation as low as 250 kGy. However, properly chosen ...

CERN Document Server

We present new low resolution Spitzer mid-infrared spectroscopy of a sample of 20 ROSAT selected local Narrow Line Seyfert 1 galaxies (NLS1s). We detect strong AGN continuum in all and clear PAH emission in 70% of the sources. The 6.2 micron PAH luminosity spans three orders of magnitudes, from ~10^(39) erg/s to ~10^(42) erg/s providing strong evidence for intense ongoing star formation in the circumnuclear regions of these sources. Using the IRS/Spitzer archive we gather a large number of additional NLS1s and their broad line counterparts (BLS1s) and constructed NLS1 and BLS1 sub-samples to compare them in various ways. The comparison shows a clear separation according to FWHM(H_beta) such that objects with narrower broad H_beta lines are the strongest PAH emitters. We test this division in various ways trying to remove biases due to luminosity and aperture size. Specifically, we find that star formation activity around NLS1 AGN is larger than around BLS1 of the ...

Energy Technology Data Exchange (ETDEWEB)

A method for determining the reactivity of subcritical systems of fissile material, using neutron-noise power spectral density measurements in conjunction with a /sup 252/Cf source, has been tested in experiments with an aqueous solution containing uranium fluoride (4.95 wt% /sup 235/U). The kappasub(eff)-values obtained from the ratio of spectral densities G*/sub 12/G/sub 13//G/sub 11/G/sub 23/ agreed with those from break-frequency noise analysis and with bias-corrected transport theory calculations within the statistical uncertainty of the measurements. Corrections for the effects of spatial modes and source-detector locations appear to be well-understood, since measurements for a variety of source-detector positions resulted in essentially the same kappasub(eff)-values. Modal correction factors were such that ignoring them would result in higher values of kappasub(eff) than actually occur. The measurements have demonstrated the applicability of the /sup ...

International Nuclear Information System (INIS)

A balanced braking system comprising a plurality of braking assemblies located about a member to be braked. Each of the braking assemblies consists of a spring biased piston of a first material fitted into a body of a different material which has a greater contraction upon cooling than the piston material. The piston is provided with a recessed head portion over which is positioned a diaphragm and forming a space therebetween to which is connected a pressurized fluid supply. The diaphragm is controlled by the fluid in the space to contact or withdraw from the member to be braked. A cooling device causes the body within which the piston is fitted to contract more than the piston, producing a tight shrink fit therebetween. The braking system is particularly applicable for selectively braking an arbor of an electron microscope which immobilizes, for example, a vertically adjustable low temperature specimen holder during observation. The system provides balanced ...

CERN Document Server

We examine the accretion properties in a sample of 42 hard (3-60keV) X-ray selected nearby broad-line AGNs. The energy range in the sample is harder than that usually used in the similar previous studies. These AGNs are mainly complied from the RXTE All Sky Survey (XSS), and complemented by the released INTEGRAL AGN catalog. The black hole masses, bolometric luminosities of AGN, and Eddington ratios are derived from their optical spectra in terms of the broad H$\\beta$ emission line. The tight correlation between the hard X-ray (3-20keV) and bolometric/line luminosity is well identified in our sample. Also identified is a strong inverse Baldwin relationship of the H$\\beta$ emission line. In addition, all these hard X-ray AGNs are biased toward luminous objects with high Eddington ratio (mostly between 0.01 to 0.1) and low column density ($<10^{22} \\mathrm{cm^{-2}}$), which is most likely due to the selection effect of the surveys. The hard X-ray luminosity is ...

International Nuclear Information System (INIS)

We theoretically model a nuclear-state preparation scheme that increases the coherence time of a two-spin qubit in a double quantum dot. The two-electron system is tuned repeatedly across a singlet-triplet level-anticrossing with alternating slow and rapid sweeps of an external bias voltage. Using a Landau-Zener-Stueckelberg model, we find that in addition to a small nuclear polarization that weakly affects the electron spin coherence, the slow sweeps are only partially adiabatic and lead to a weak nuclear spin measurement and a nuclear-state narrowing which prolongs the electron spin coherence. This resolves some open problems brought up by a recent experiment. We also show that the electronic two-spin states singlet and triplet T_+ are promising candidates for the implementation of a qubit in GaAs double quantum dots (DQD). A coherent superposition of the two-spin states is obtained by finite time Landau-Zener-Stueckelberg interferometry and the single qubit ...

CERN Document Server

We directly measure the evolution of the intergalactic Lyman-alpha effective optical depth, tau_eff, over the redshift range 2 is <1% at z=2, 4% at z=3, and 12% at z=4. Previous measurements of tau_eff at 3biased low. We provide estimates of the level of absorption arising from metals in the Ly-alpha forest based on both direct and statistical metal removal results in the literature, finding that this contribution is ~6-9% at z=3 and decreases monotonically with redshift. The high precision of our measurement, attaining 3% in redshift bins of width Delta z=0.2 aro und z=3, indicates significant departures from the best-fit power-law redshift evolution (tau_eff=0.0018(1+z)^3.92, when metals are left in), particularly near z=3.2. The observed downward departure is statistically consistent with a similar feature detected in ...

Energy Technology Data Exchange (ETDEWEB)

Because the bridges over the Rio Grande were to be razed, the investigators were able to introduce simulated cracks in four stages of increasing length into the structure. This paper summarizes the results of ambient and conventional, measured-input, modal analyses, performed on the undamaged structure. Also summarized are the results of conventional modal analyses performed after each stage of damage had been introduced. These tests were intended to quantify the amount of damage necessary to produce changes in the global dynamic properties of the bridge and to form a data base that can be used by other investigators to develop damage identification algorithms. Conventional modal analysis identified changes in the global dynamic properties of the structure only after the final stage of a damage.

British Library Electronic Table of Contents (United Kingdom)

The aim of this study was to evaluate the differences in accuracy of dose calculation between 3 commonly used algorithms, the Pencil Beam algorithm (PB), the Anisotropic Analytical Algorithm (AAA), and the Collapsed Cone Convolution Superposition (CCCS) for intensity-modulated radiation therapy (IMRT). The 2D dose distributions obtained with the 3 algorithms were compared on each CT slice pixel by pixel, using the MATLAB code (The MathWorks, Natick, MA) and the agreement was assessed with the gamma function. The effect of the differences on dose-volume histograms (DVHs), tumor control, and normal tissue complication probability (TCP and NTCP) were also evaluated, and its significance was quantified by using a nonparametric test. In general PB generates regions of over-dosage both in the l...

British Library Electronic Table of Contents (United Kingdom)

Aquatic sediments feature a two-way interaction between contaminants and benthic macrofauna. The effect of the macrofauna community on the transport of contaminants in sediment has received considerable attention. Yet, few studies have investigated the reverse effect, i.e., the influence of contaminants on bioturbation activity. To this end, we performed laboratory experiments to investigate the effect of copper contamination on sediment reworking activity of the ragworm Nereis diversicolor. A density of 570 ind m2 was introduced in mesocosms containing natural and copper spiked (2.99 nmol Cu g?1) cohesive intertidal sediments from Ponta da Erva (Tejo estuary, Portugal). Luminophore tracers were used to quantify sediment reworking activity over time (2, 7, 14 and 21 days). Bioturbation was...

Energy Technology Data Exchange (ETDEWEB)

Alloy 800 has been used for steam generator (SG) tubing for more than 30 years, primarily in CANDU reactors worldwide and in reactors in Germany. Extensive laboratory testing and in-service experience suggest that the Alloy 800 tubing has excellent resistance to corrosion-related degradation under appropriate operating conditions. In planning refurbishment of nuclear plants stations, a key concern is the longevity of existing SGs up to the 60-year lifetime of the refurbished plant. The paper reviews an existing methodology based on the concept of the improvement factor, and refines its estimation based on data specific to CANDU operating conditions. The paper presents a more advanced Bayesian probabilistic approach to estimate the degradation free lifetime distribution of Alloy 800 tubing, which is used to quantify the probability of degradation during the service life and to evaluate the impact of potential occurrences of degradation on reliability of SG tubing.

CERN Document Server

We address the deviations of the scaling relations of elliptical galaxies from the expectations based on the virial theorem and homology, including the "tilt" of the "fundamental plane" and the steep decline of density with mass. We show that such tilts result from dissipative major mergers once the gas fraction available for dissipation declines with progenitor mass, and derive the scaling properties of the progenitors. We use hydrodynamical simulations to quantify the effects of major mergers with different gas fractions on the structural properties of galaxies. The tilts are driven by the differential shrinkage of the effective stellar radius as a function of dissipation in the merger, while the correlated smaller enhancements in internal velocity and stellar mass keep the slope of the velocity-stellar mass relation near V \\pr M_*^{1/4}. The progenitors match a straightforward model of disc formation in LCDM haloes. Their total to stellar mass ratio within the ...

CERN Document Server

Bedwyr is a generalization of logic programming that allows model checking directly on syntactic expressions possibly containing bindings. This system, written in OCaml, is a direct implementation of two recent advances in the theory of proof search. The first is centered on the fact that both finite success and finite failure can be captured in the sequent calculus by incorporating inference rules for {\\em definitions} that allow {\\em fixed points} to be explored. As a result, proof search in such a sequent calculus can capture simple model checking problems as well as may and must behavior in operational semantics. The second is that higher-order abstract syntax is directly supported using term-level $\\lambda$-binders and the quantifier known as $\

Science.gov (United States)

A phase 2 study has been initiated to investigate surfactant-assisted coal liquefaction, with the objective of quantifying the enhancement in liquid yields and product quality. This report covers the second quarter of work. The major accomplishments were: completion of coal liquefaction autoclave reactor runs with Illinois number 6 coal at processing temperatures of 300, 325, and 350 C, and pressures of 1800 psig; analysis of the filter cake and the filtrate obtained from the treated slurry in each run; and correlation of the coal conversions and the liquid yield quality to the surfactant concentration. An increase in coal conversions and upgrading of the liquid product quality due to surfactant addition was observed for all runs.

Science.gov (United States)

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

British Library Electronic Table of Contents (United Kingdom)

PurposeThis study evaluates changes in recall of combat exposures over the first year after return from deployment. The research purpose is to assess whether recall of combat exposures is consistent at different time points; if not, what demographic and/or PTSD symptom risk factors exist for any directional instability. MethodsSurveys completed by soldiers at 3, 6, and 12 months post-Operation Iraqi Freedom (OIF) deployment were linked for longitudinal analysis in a previous study in which three matched datasets were created: 3-6 months (N = 768), 6-12 months (N = 341), and 3-12 months (N = 445). Post-traumatic stress disorder (PTSD) was assessed by using the National Center for PTSD Checklist. The reliability of recall for 36 combat exposures was quantified. The effects of demographics an...

British Library Electronic Table of Contents (United Kingdom)

Abstract Global mean temperature is predicted to increase by 2 7 C and precipitation to change across the globe by the end of this century. To quantify climate effects on ecosystem processes, a number of climate change experiments have been established around the world in various ecosystems. Despite these efforts, general responses of terrestrial ecosystems to changes in temperature and precipitation, and especially to their combined effects, remain unclear. We used meta analysis to synthesize ecosystem level responses to warming, altered precipitation, and their combination. We focused on plant growth and ecosystem carbon (C) balance, including biomass, net primary production (NPP), respiration, net ecosystem exchange (NEE), and ecosystem photosynthesis, synthesizing results from 85 studi...

British Library Electronic Table of Contents (United Kingdom)

We quantified the impacts of hot summer air temperatures on tourism in the Swiss Alps by analysing the relationship between temperature and overnight stays in 40 Alpine resorts. Several temperature thresholds were tested to detect the relationship between them and summer tourism. Our results reveal significant correlations between the number of nights spent in mountain resorts and hot temperatures at lower elevations. The relationship between hot temperatures and overnight stays is more important in June and to a lesser extent in August than in July. This is probably because holidays and the peak of domestic tourist demand in summer usually take place between the beginning of July and mid-August so that long-term planned stays dominate more during these months compared to June. The alpine ...

British Library Electronic Table of Contents (United Kingdom)

The aim of this study was to assess the feasibility of radiosterilization of drugs aqueous solutions and to evaluate the effects of some additives, such as mannitol, nicotinamide and pyridoxine, which might protect the drug from degradation. Metoclopramide was selected as a model drug. The structures of the degradation products were determined to gain insight on the radiolysis mechanisms in aqueous solution in order to design strategies to lower the drug degradation.Metoclopramide hydrochloride aqueous solutions with and without excipients were irradiated either with gamma rays or high-energy electrons. HPLC-DAD was used to measure the loss of chemical potency and to quantify the degradation products which were also characterized by LC-APCI-MS-MS. Metoclopramide recovery for gamma and elec...

British Library Electronic Table of Contents (United Kingdom)

The Pacific white shrimp, Litopenaeus vannamei, is the most important shrimp species in volume in world aquaculture. However, in recent decades, outbreaks of diseases, especially viral diseases, have led to significant economic losses, threatening the sustainability of shrimp farming worldwide. In 2004, Brazilian shrimp farming was seriously affected by a new disease caused by the Infectious myonecrosis virus (IMNV). Thus, disease control based on rapid and sensitive pathogen detection methods has become a priority. In this study, a specific quantitation method for IMNV was developed using real-time PCR with SYBR Green chemistry and viral load of the principal target tissues of chronically infected animals was quantified. The quantitative analysis revealed that mean viral load ranged from ...

International Nuclear Information System (INIS)

In this work an analysis of the influence of the choice of the algorithm or planning system, on the calculus of the same treatment plan is introduced. For this purpose specific software has been developed for comparing plans of a series of IMRT cases of prostate and head and neck cancer calculated using the convolution, superposition and fast superposition algorithms implemented in the XiO 4.40 planning system (CMS). It has also been used for the comparison of the same treatment plan for lung pathology calculated in XiO with the mentioned algorithms, and calculated in the Plan 4.1 planning system (Brainlab) using its pencil beam algorithm. Differences in dose among the treatment plans have been quantified using a set of metrics. The recommendation for the dosimetrist of a careful choice of the algorithm has been numerically confirmed. (Author).

International Nuclear Information System (INIS)

Accelerator mass spectrometry (AMS) represents a powerful technique for the detection of long-lived radionuclides through ultra-low isotope ratio measurements. In many cases, counting atoms rather than decays yields much higher sensitivities. The potential of AMS will be demonstrated on typical radionuclides of interest with half-lives between some tens of years up to a hundred million years. The precise measurement of the 27Al(n,2n)26Al excitation function will be exemplified. Lack of information exists for a list of nuclides as pointed out by nuclear data requests. A brief overview on detection limits and some applications for selected long-lived radionuclides is given.

CERN Document Server

The Fourier transform of cosmological density perturbations can be represented in terms of amplitudes and phases for each Fourier mode. We investigate the phase evolution of these modes using a mixture of analytical and numerical techniques. Using a toy model of one-dimensional perturbations evolving under the Zel'dovich approximation as an initial motivation, we develop a statistic that quantifies the information content of the distribution of phases. Using numerical simulations beginning with more realistic Gaussian random-phase initial conditions, we show that the information content of the phases grows from zero in the initial conditions, first slowly and then rapidly when structures become non-linear. This growth of phase information can be expressed in terms of an effective entropy: Gaussian initial conditions are a maximum entropy realisation of the initial power spectrum, gravitational evolution decreases the phase entropy. We show that our definition of ...

British Library Electronic Table of Contents (United Kingdom)

To determine whether PKH26 labeling affects the morphologies, phenotypes, proliferation, and secretion abilities of human umbilical mesenchymal stromal cells (HUMSCs) were investigated. Isolated HUMSCs were labeled with PKH26, and cell morphology was observed under microscope. Cell cycle, apoptotic cell death, expression of PKH26, and the proliferation rate were evaluated. Additionally, fluorescence intensity of PKH26 labeling at different passage times was quantified. There were no detectable differences in cell morphology, cell growth, and proliferation rate after PKH26 labeling. In addition, fluorescence intensity of PKH26 labeling was gradually reduced with increase of the passage times. The PKH26 labeling disappeared after passage six times. In summary, PKH26 labeling is a safe and ef...

CERN Document Server

Grating cloaks are a variation of dielectric carpet (or ground- plane) cloaks. The latter were introduced by Li and Pendry. In contrast to the numerical work involved in the quasi-conformal carpet cloak, the refractive-index profile of a conformal grating cloak follows a closed and exact analytical form. We have previously mentioned that finite-size conformal grating cloaks may exhibit better cloaking than usual finite-size carpet cloaks. In this letter, we directly visualize their performance using photorealistic ray-tracing simulations. We employ a Newtonian approach that is advantageous compared to conventional ray tracing based on Snell's law. Furthermore, we quantify the achieved cloaking quality by computing the cross-correlations of rendered images. The cross-correlations for the grating cloak are much closer to 100% (i.e., ideal) than those for the Gaussian carpet cloak.

British Library Electronic Table of Contents (United Kingdom)

A microcosm laboratory experiment was conducted to determine the impact of biological reworking by the ragworm Nereis diversicolor on the redistribution of particle-bound radionuclides deposited at the sediment-water interface. Over the course of the 40-day experiment, as much as 35% of a 137Cs-labelled particulate tracer deposited on the sediment surface was redistributed to depths of up to 11 cm by the polychaete. Three different reworking models were employed to model the profiles and quantify the biodiffusion and biotransport coefficients: a gallery-diffuser model, a continuous sub-surface egestion model and a biodiffusion model. Although the biodiffusion coefficients obtained for each model were quite similar, the continuous sub-surface egestion model provided the best fit to the data...

Science.gov (United States)

To quantify the opportunities for natural gas and identify technological advances needed to capture such opportunities, the mineral-wool industry was analyzed with respect to the principal companies, their capabilities, and markets. The mineral-wool industry is stable with a slightly declining market. Of its market segments, only commercial acoustic insulation (which is currently dominant) is likely to be affected by growth in the next ten years. The principal process is based on treatment of blast-furnace slags in a cupola furnace using coke as the fuel and reducing agent. Expanded use of gas, as a substitute for coke, would eliminate environmental problems and expand the latitude of suitable raw materials. The study provides insights into the mineral-wool industry and identifies factors that may constitute bases for future usage of natural gas.

British Library Electronic Table of Contents (United Kingdom)

Determining which kinds of roots are likely to be consumed by root herbivores may improve our understanding of the mechanistic control on fine root dynamics. Here, we tested the hypothesis that root herbivores prefer to consume the distal lower order roots in their branching networks. Insecticide was applied to soil to quantify effects of root herbivores on root biomass and production in the first five orders (the distal roots numbered as first-order) in Fraxinus mandshurica and Larix gmelinii plantations from May 2008 to July 2009. Root morphology, chemistry, anatomy and physiology were measured simultaneously across branching orders. Among the first five order roots, significant consumptions by herbivores were found only for the two distal lower order roots throughout growing seasons, wi...

CERN Document Server

We report on the magnetic hyperthermia properties of chemically synthesized ferromagnetic 11 and 16 nm Fe(0) nanoparticles of cubic shape displaying the saturation magnetization of bulk iron. The specific absorption rate measured on 16 nm nanocubes is 1690+-160 W/g at 300 kHz and 66 mT. This corresponds to specific losses-per-cycle of 5.6 mJ/g, largely exceeding the ones reported in other systems. A way to quantify the degree of optimization of any system with respect to hyperthermia applications is proposed. Applied here, this method shows that our nanoparticles are not fully optimized, probably due to the strong influence of magnetic interactions on their magnetic response. Once protected from oxidation and further optimized, such nano-objects could constitute efficient magnetic cores for biomedical applications requiring very large heating power.

British Library Electronic Table of Contents (United Kingdom)

The spatio-temporal dynamics of an impinging shock/boundary layer interaction at Mach 2 and under incipient separation conditions, has been investigated experimentally by means of high-speed particle image velocimetry (PIV). The available PIV acquisition rate of up to 20 kHz permits a time-resolved characterization of the interaction. The dynamics of different flow regions?notably the separation region and the reflected shock?were quantified by means of temporal auto-correlation fields and pseudo-spectral analysis. The PIV data further enable to investigate the relationship between spatially extended flow features, such as shock position and bubble size, as well as the influence of the upstream boundary layer. The results confirm earlier studies that there is an important upstream effect o...

British Library Electronic Table of Contents (United Kingdom)

Sulfur mustard (HD) is an alkylating and cytotoxic chemical warfare agent, which inflicts severe skin toxicity and an inflammatory response. Effective medical countermeasures against HD-caused skin toxicity are lacking due to limited knowledge of related mechanisms, which is mainly attributed to the requirement of more applicable and efficient animal skin toxicity models. Using a less toxic analog of HD, chloroethyl ethyl sulfide (CEES), we identified quantifiable inflammatory biomarkers of CEES-induced skin injury in dose- (0.05-2 mg) and time- (3-168 h) response experiments, and developed a CEES-induced skin toxicity SKH-1 hairless mouse model. Topical CEES treatment at high doses caused a significant dose-dependent increase in skin bi-fold thickness indicating edema. Histopathological e...

Energy Technology Data Exchange (ETDEWEB)

This research aims to develop reliable, advanced system thermal-hydraulic computer code and to quantify the uncertainties of code to introduce the best estimate methodology of ECCS for LBLOCA. Although the one of best estimate code, RELAP5/MOD3.1 was introduced from USNRC, several deficiencies in its reflood model and some improvements have been made. The improvements consist of modification of reflood wall heat transfer package and adjusting the drop size in dispersed flow regime. The tome smoothing of wall vaporization and level tracking model are also added to eliminate the pressure spike and level oscillation. For the verification of improved model and quantification of associated uncertainty, the FLECHT-SEASET data were used and upper limit of uncertainty at 95% confidence level is evaluated. (Author) 30 refs., 49 figs., 2 tabs.

British Library Electronic Table of Contents (United Kingdom)

PurposeWe objectively quantified the gain in urethral diameter and the effect of stenting after tubularized incised plate urethroplasty in a rabbit hypospadias model. Materials and MethodsWe created a hypospadias model in 12 New Zealand white male rabbits by excising the ventral urethra. A 3 cm tattoo line was made longitudinally in the dorsal urethral plate midline. Two weeks later a 2 cm relaxing incision was made in the middle part of the tattooed line. The stretched incision width between the tattooed edges was measured, followed by urethral plate tubularization. Six rabbits were stented and 6 were nonstented. Two weeks later the animals were sacrificed and the distance separating the tattoo was measured at the midpoint of the tattooed line. Transverse sections at this point were exami...

International Nuclear Information System (INIS)

In quantifying health risks arising from radiation exposure and synergistic effects promoted by radiation the dose-effect relationship must be used as a basis. Special problems arise in the extrapolation of experimental results or in the treatment of data in the region of low doses administered over long periods of time. For radiation protection purposes, especially manifestations of cancer and genetic effects are significant. The International Commission on Radiation Protection has published binding guiding values on the basis of which to assess the risk of cancer. The cancer risk and genetic risks are estimated for relevant dose ranges and compared with other factors of civilization. For the most important chemical pollutants emitted into the environment the possibilities of impacts arising from synergistic effects are discussed on the basis of the rules and regulations specified in German antipollution legislation. (orig.) 891 HP/orig. 892 MKO.

British Library Electronic Table of Contents (United Kingdom)

Summary The objective of this study was to quantify the genetic diversity among breeds under evaluation for tropical adaptability traits that affect the performance of beef cattle at the USDA/ARS SubTropical Agricultural Research Station (STARS) near Brooksville, FL, USA. Twenty-six microsatellite loci were used to estimate parameters of genetic diversity among the breeds American Brahman, Angus, Senepol and Romosinuano; the latter was comprised of two distinct bloodlines (Costa Rican and Venezuelan). Genotypes of 47 animals from each of these STARS herds were analysed for genetic diversity and genetic distance. Using two methods, the greatest genetic distance was detected between the Costa Rican line of Romosinuano and the Senepol. Gene diversity ranged between 0.64 (Costa Rican line of R...

British Library Electronic Table of Contents (United Kingdom)

The use of natural gas in China is still relatively immature, as gas production only supplies a low percentage of the domestic energy system. In contrast, Chinese economy mainly relies on coal with a 67% share of the total primary energy supply. The environmental impact from this high coal dependence is significant and planners have sought for cleaner energy sources. Natural gas is both cleaner and generally more efficient than coal and gas consumption is rising quickly due to these facts. The growth tendency indicates that natural gas will become an important substitution for coal in some parts of the Chinese primary energy consumption. To quantify this tendency, this paper uses a system dynamics model to create a possible outlook. The results show that the gas consumption in China will c...

International Nuclear Information System (INIS)

An attempt to develop a simple framework for financial evaluation of renewable energy technologies (RETs) such as photovoltaic (PV) pump, windmill pump, biogas and producer gas-driven dual fuel engine pumps for irrigation water pumping has been made. The unit cost of water and unit cost of useful energy delivered by the RETs have been estimated. The monetary benefits that accrued to the end-user have been quantified in terms of the amount of diesel or electricity saved. Financial figures of merit for the investments made in the RETs have been estimated. The effect of fuel price escalation on these measures of financial performance has also been evaluated along with the estimation of the break-even prices of fuels likely to be substituted by RETs. Results of some exemplifying calculations are presented and briefly discussed.

British Library Electronic Table of Contents (United Kingdom)

The rational use of energy has become a priority for all industries in Brazil, mainly after the energy rationing in 2001. Methodologies to quantify and improve the performance of plants that consume and generate electricity and thermal energy are being used to reach this goal. Exergoeconomic analysis provides a complete diagnosis of a plant, both in exergetic and in monetary values. This study shows the methodology used to assess the power generation system of the Companhia Siderurgica Tubarao (CST). The current system is based on a regenerative Rankine cycle using two gases from steel production - blast furnace gas (BFG) and coke oven gas (COG) - to generate electric power and occasionally steam for the process. Use of the Theory of Exergetic Cost allowed determination of monetary and exe...

British Library Electronic Table of Contents (United Kingdom)

The iron foundry industry is considered to be a potential source of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). This study investigated the emission factors and total emission amounts of PCDD/Fs and dioxin-like polychlorinated biphenyls (DL-PCBs) from iron foundries in China. The concentrations and the World Health Organization toxicity equivalents (WHO-TEQs) are presented and the congener profiles are discussed in this paper. In the present work, 26 fly ash samples were collected and tested to quantify the PCDD/Fs and DL-PCBs generated by 14 plants of different scales, and five stack gas samples were collected from two (named as EFG and LFG) of those plants. The emission levels of PCDD/Fs and DL-PCBs indicated that hot-air cupolas had lower emissions than cold-air cupol...

British Library Electronic Table of Contents (United Kingdom)

Academic, government, and industrial field researchers have generated a significant database of field studies of the volatility of soil applied fumigants. However, limited work exists in validating physical models against field volatility data sets and fully exploring the volatility parametric response surface. Field studies quantifying atmospheric flux for soil fumigants 1,3-dichloropropene and chloropicrin are validated against the United States Department of Agriculture (USDA Salinity Laboratory) soil physics model CHAIN_2D that was modified specifically for agronomic uses of soil fumigants. Comparison between model predictions and field observations for six unique field trials in five different states indicate that CHAIN_2D effectively captures the magnitude and duration of fumigant em...

International Nuclear Information System (INIS)

In order to quantify the biomass burning emissions, the main atmospheric pollution source of tropical and subtropical regions, we carried out the analysis of ashes that are also formed during these fires. To this end, we developed analytical methods to characterize the composition of savannah grass burning ashes by using X-ray fluorescence for mineral elements and microanalysis for C, H, O and N. Samples used in this work have been collected during laboratory combustion experiments, with chemically well-defined natural savannah grasses from Ivory Coasts and South Africa. The reproducibility and efficiency of different developed procedures have been studies. The analytical relative precision is generally better than 5%. This development has allowed to establish, for the first time, the global mass balance of ashes resulting from savannah grass burning. (authors). 16 refs., 3 figs., 8 tabs.

Science.gov (United States)

Digital audio sampling is explained, and some of its implications in digital sound applications are discussed. Digital sound equipment is rapidly replacing analog recording devices as the state-of-the-art in audio technology. The philosophy of digital recording involves doing away with the continuously variable analog waveforms and turning the patterns into numbers. A digital recording device rapidly samples the incoming sounds, quantifying the signal into a series of numerical values (binary codes). Although digital sound eliminates many of the traditional analog problems, digital signal processing presents key problems in sampling rates and synchronization. Careful control is necessary to check signals through each step in the audio chain. The advantages of digital audio processing include increased signal-to-noise ratio, no flutter, transparent generation of copies, and sound manipulation. These benefits come with increased quality control requirements. One ...

Energy Technology Data Exchange (ETDEWEB)

The black carbon continuum is composed of a series of carbon-rich components derived from combustion or metamorphism and characterized by contrasting environmental behavior and susceptibility to oxidation. In this work, we present a micro-scale density fractionation method that allows isolating the small quantities of soot-like and graphitic material usually found in natural samples. Organic carbon and {delta}{sup 13}C mass balance calculations were used to quantify the relative contributions of the two fractions to thermally-stable organic matter from a series of aquatic sediments. Varying proportions of soot-like and graphitic material were found in these samples, with large variations in {delta}{sup 13}C signatures suggesting important differences in their origin and/or dynamics in the environment.