WorldWideScience
1

Evolution of a molecular switch: universal bacterial GTPases regulate ribosome function.  

Science.gov (United States)

The GTPases comprise a protein superfamily of highly conserved molecular switches adapted to many diverse functions. These proteins are found in all domains of life and often perform essential roles in fundamental cellular processes. Analysis of data from genome sequencing projects demonstrates that bacteria possess a core of 11 universally conserved GTPases (elongation factor G and Tu, initiation factor 2, LepA, Era, Obg, ThdF/TrmE, Ffh, FtsY, EngA and YchF). Investigations aimed at understanding the function of GTPases indicate that a second conserved feature of these proteins is that they elicit their function through interaction with RNA and/or ribosomes. An emerging concept suggests that the 11 universal GTPases are either necessary for ribosome function or transmitting information from the ribosome to downstream targets for the purpose of generating specific cellular responses. Furthermore, it is ...

2001-07-01

2

The dynamin-related GTPase Opa1 is required for glucose-stimulated ATP production in pancreatic beta cells  

UK PubMed Central (United Kingdom)

Previous studies using in vitro cell culture systems have shown the role of the dynamin-related GTPase Opa1 in apoptosis prevention and mitochondrial DNA (mtDNA) maintenance. However, it remains to...Full Text Available

2011-07-01

3

The Rab GTPase RabA4d Regulates Pollen Tube Tip Growth in Arabidopsis thaliana[W  

UK PubMed Central (United Kingdom)

During reproduction in flowering plants, pollen grains form a tube that grows in a polarized fashion through the female tissues to eventually fertilize the egg cell. These highly polarized pollen tubes...Full Text Available

2009-02-01

4

Stochastic simulation of the transducin GTPase cycle.  

UK PubMed Central (United Kingdom)

On rod disc membranes, single photoactivated rhodopsin (R*) molecules catalytically activate many copies of the G-protein (Gt), which in turn binds and activates the effector (phosphodiesterase). We...Full Text Available

1996-12-01

5

The Immunity-related GTPase Irgm3 Relieves Endoplasmic Reticulum Stress Response during Coxsackievirus B3 Infection via a PI3K/Akt Dependent Pathway.  

Science.gov (United States)

The IRG protein Irgm3 preserves cell survival during coxsackievirus B3 (CVB3) infection. However, the molecular mechanisms are not clear. Here, we examined the effect of Irgm3 expression on ER stress triggered by pharmacological agents or CVB3 infection. In Tet-On/Irgm3 HeLa cells, Irgm3 expression suppressed either chemical- or CVB3-induced upregulation of glucose-regulated protein78. Further, Irgm3 strongly inhibited the activation of both the PERK and ATF6 pathways of ER stress responses, which further led to the diminished phosphorylation of eIF2?, reduced cleavage/activation of transcription factor SREBP1 and attenuated induction of proapoptotic genes CHOP and GADD34. These data were further supported by experiments using Irgm3 knockout mouse embryonic fibroblasts, in which the ER stress induced by CVB3 was not relieved due to the lack of Irgm3 expression. In addition, the tunicamycin-triggered ER stress promoted the subsequent CVB3 infection. The effect of Irgm3 on ER stress and ...

2011-10-10

6

The mutT Defect Does Not Elevate Chromosomal Fragmentation in Escherichia coli Because of the Surprisingly Low Levels of MutM/MutY-Recognized DNA Modifications?  

UK PubMed Central (United Kingdom)

Nucleotide pool sanitizing enzymes Dut (dUTPase), RdgB (dITPase), and MutT (8-oxo-dGTPase) of Escherichia coli hydrolyze noncanonical DNA precursors to prevent incorporation of base...Full Text Available

2007-10-01

7

A C-terminal Sequence in the Guanine Nucleotide Exchange Factor Sec7 Mediates Golgi Association and Interaction with the Rsp5 Ubiquitin Ligase*  

UK PubMed Central (United Kingdom)

Arf GTPases control vesicle formation from different intracellular membranes and are regulated by Arf guanine nucleotide exchange factors (GEFs). Outside of their conserved catalytic domains, known...Full Text Available

2008-12-05

11

On the temperature dependence of the level density parameter and its effect upon neutron evaporation spectra  

Energy Technology Data Exchange (ETDEWEB)

Effects associated with the temperature dependence of the level density parameter, a(T), are investigated in connection with neutron evaporation processes. Different approximations, for this temperature dependence, are compared for the case of neutron emission from the compound nucleus /sup 209/Pb.

1987-07-01

12

Female rats display dose-dependent differences to the rewarding and aversive effects of nicotine in an age-, hormone-, and sex-dependent manner  

UK PubMed Central (United Kingdom)

IntroductionThe objective of this study was to examine age-, hormone-, and sex-dependent differences to the behavioral effects of nicotine using place-conditioning...Full Text Available

2009-10-01

13

On the A-dependence of the nuclear structure functions  

International Nuclear Information System (INIS)

The A-dependence of the nuclear structure functions is described rather well within the framework of the quark-parton-flucton model of nucleus. 16 refs. (author).

14

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

International Nuclear Information System (INIS)

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

1977-07-01

15

Children of men with alcohol dependence: Psychopathology, neurodevelopment and family environment  

UK PubMed Central (United Kingdom)

Background:Children of people with alcohol dependence (COAs) are at high risk for behavioral and cognitive problems.Aim:Aim of...Full Text Available

2010-10-01

27

A Stress-Dependent Hysteresis Model for Ferroelectric ...  

Science.gov (United States)

... Attributes and limitations of the charac- terization framework are illustrated through comparison with experimental PLZT data. ...

2011-05-13

28

Effects of velocity-dependent force on the magnetic form factors of odd-Z  

International Nuclear Information System (INIS)

We investigate the effects of the velocity-dependent force on the magnetic form factors and magnetic moments of odd-Z nuclei. The form factors are calculated with the harmonic-oscillator wavefunctions. It is found that the contributions of the velocity-dependent force manifest themselves in the very large momentum transfer region (q?4 fm-1). In the low and medium q region the contributions of the velocity-dependent force are very small compared with those without this force. However, in the high-q region the contributions of the velocity-dependent force are larger than the normal form factors. The diffraction structures beyond the existing experimental data are found after the contributions of the velocity-dependent force are included. The formula of the correction to the single particle magnetic moment due to the velocity-dependent force is reproduced exactly ...

2008-03-01

29

Time-dependent, finite, rotating universes  

International Nuclear Information System (INIS)

Three new classes of finite, homogeneous and nonsingular solutions of Einstein's equations which have time-dependent expansion, shear and rotation are presented. The t-constant sections are of Bianchi type IX. The source of these geometries is a fluid which has not been thermalized. (Author).

30

Time-dependent, Bianchi II, rotating universe  

International Nuclear Information System (INIS)

An exact cosmological solution of Einstein's equations which has time-dependent rotation is presented. The t-constant sections are of Bianchi type II. The source of this geometry is a fluid which has not been thermalized. (Author).

2006-11-03

31

The relative roles of bipolar disorder and psychomotor agitation in substance dependence  

UK PubMed Central (United Kingdom)

Previous studies have shown that both bipolar disorder (BPD) and psychomotor agitation (PMA) are associated with substance dependence. These two findings have yet to be integrated, despite evidence...Full Text Available

2010-06-01

32

The Bidimensional Stefan Problem with Convection: The Time-Dependent Case.  

Science.gov (United States)

This paper considers the time dependent Stefan problem with convection in the fluid phase governed by the Stokes equation, and with adherence of the fluid on the lateral boundaries. The existence of a weak solution is obtained via the introduction of a te...

1982-01-01

33

Temperature Dependence of Structure, Bending Rigidity, and Bilayer Interactions of Dioleoylphosphatidylcholine Bilayers  

UK PubMed Central (United Kingdom)

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

2008-01-01

34

Structure functions of nuclei in fluctonic model with rescaling  

International Nuclear Information System (INIS)

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

35

Rapid aneuploidy detection with multiplex ligation-dependent probe amplification: a prospective study of 4000 amniotic fluid samples  

UK PubMed Central (United Kingdom)

The introduction of prenatal screening requires rapid high-throughput diagnosis of common aneuploidies. Multiplex ligation-dependent probe amplification (MLPA) allows for quick, easily automated multiplex...Full Text Available

2009-01-01

36

Mechanism of Na(+)-dependent citrate transport in Klebsiella pneumoniae.  

UK PubMed Central (United Kingdom)

Citrate transport via CitS of Klebsiella pneumoniae has been shown to depend on the presence of Na+. This transport system has been expressed in Escherichia coli, and uptake of citrate in E. coli membrane...Full Text Available

1992-08-01

37

Hydrodynamics of primordial black hole formation: dependence on the equation of state  

Energy Technology Data Exchange (ETDEWEB)

An analysis is made of the manner in which the process of primordial black-hole formation and the subsequent accretion of gas depend on the equation of state. On the assumption that the process is spherically symmetric, the problem is solved numerically.

1980-03-01

38

Glutamate Receptor-Mediated Restoration of Experience-Dependent Place Field Expansion Plasticity in Aged Rats  

UK PubMed Central (United Kingdom)

Place fields of hippocampal pyramidal cells expand asymmetrically when adult rats repeatedly follow the same route. This behaviorally-induced expression of neuronal plasticity utilizes an NMDAR-dependent,...Full Text Available

2008-06-01

39

Empirically Defined Subtypes of Alcohol Dependence in an Irish Family Sample  

UK PubMed Central (United Kingdom)

Alcohol dependence (AD) is clinically and etiologically heterogeneous. The goal of this study was to explore AD subtypes among a sample of 1, 221 participants in the Irish Affected Sib Pair...Full Text Available

2010-03-01

40

Dynamin-dependent NMDAR endocytosis during LTD and its dependence on synaptic state  

UK PubMed Central (United Kingdom)

BackgroundThe N-methyl-D-aspartate (NMDA)-type glutamate receptor expressed at excitatory glutamatergic synapses is required for learning and memory and is critical for normal brain...Full Text Available

41

Coping with crowds: Density-dependent disease resistance in desert locusts  

UK PubMed Central (United Kingdom)

Parasite transmission generally exhibits some form of positive density dependence. Thus, as population density increases, so too does the per capita risk of becoming infected. Under...Full Text Available

2002-04-16

42

Collapse and Restoration of MHC Class-I-Dependent Immune Privilege  

UK PubMed Central (United Kingdom)

The collapse of major histocompatiblity complex (MHC) class-I-dependent immune privilege can lead to autoimmune disease or fetal rejection. Pragmatic and instructive models are needed to clarify the...Full Text Available

2004-02-01

43

Cell-density-dependent Changes in the Metabolism of Chloronema Cell Cultures  

UK PubMed Central (United Kingdom)

In the growing chloronema cell suspension cultures of the moss Funaria hygrometrica Hedw., activities of several enzymes have been found to be cell-density-dependent. Cyclic nucleotide...Full Text Available

1979-07-01

44

Caveolin-1 as a Novel Indicator of Wound-Healing Capacity in Aged Human Corneal Epithelium  

UK PubMed Central (United Kingdom)

Excess caveolin-1 has been reported to play a role in age-dependent hyporesponsiveness to growth factors in vitro. Therefore, we hypothesized that caveolin-1–dependent hyporesponsiveness...Full Text Available

2010-11-01

45

Bimodal MR-PET agent for quantitative pH imaging  

UK PubMed Central (United Kingdom)

Activatable or “smart” magnetic resonance contrast agents have relaxivities that depend on environmental factors such as pH or enzymatic activity, but the MR signal depends on...Full Text Available

2010-03-22

46

A structural determinant required for RNA editing  

UK PubMed Central (United Kingdom)

RNA editing by adenosine deaminases acting on RNAs (ADARs) can be both specific and non-specific, depending on the substrate. Specific editing of particular adenosines may depend on the overall sequence...Full Text Available

2011-07-01

51

A Structural Approach to the Photonic Processor  

Science.gov (United States)

... UUV Unmanned Underwater Vehicle ... 26- VISION-ASSISTED ROBOT TASKS ... Specifically, the development of autonomous robots depends on ...

2011-05-14

52

"2"0"3Pb yields while irradiating thallium with protons and deuterons  

International Nuclear Information System (INIS)

... data deuteron beams energy dependence errors gamma radiation lead 203

53

Empirically defined subtypes of alcohol dependence in an Irish family sample  

British Library Electronic Table of Contents (United Kingdom)

Alcohol dependence (AD) is clinically and etiologically heterogeneous. The goal of this study was to explore AD subtypes among a sample of 1221 participants in the Irish Affected Sib Pair Study of Alcohol Dependence, all of whom met DSM-IV criteria for AD. Variables used to identify the subtypes included major depressive disorder, antisocial personality disorder, illicit drug dependence (cannabis, sedatives, stimulants, cocaine, opioids, and hallucinogens), nicotine dependence, the personality traits of neuroticism and novelty seeking, and early alcohol use. Using latent class analysis, a 3-class solution was identified as the most parsimonious description of the data. Individuals in a Mild class were least likely to have comorbid psychopathology, whereas a severe class had highest probabi...

2010-01-01

54

Dose dependence of semiconductor material conductivity as a means of high fluence dosimetry  

Energy Technology Data Exchange (ETDEWEB)

Dose dependences of conductivity at a temperature of 78 K for InSb and InAs single crystals under reactor fast neutron, 50 MeV proton and 80 MeV alpha particle irradiation up to fluence of 10{sup 17} cm{sup -2} are considered. Special attention is given to non-trivial, but little known semi-conductor characteristics in terms of {sigma}(F) dependence at large fluences, and also to the versatility of such dependence for all semiconductors. The behaviour of semiconductor materials conductivity dependence on fluence presented here may be used for semiconductor dosemeters characterisitic variation forecasting under large fluence measurements and in radiation emergency dosimetry. (author).

1996-12-31

55

The dependence of radiation hardening and embrittlement on irradiation temperature  

International Nuclear Information System (INIS)

Assessments of the hardening and embrittlement of pressure vessel steels and welds as a function of neutron dose use trend curves derived from surveillance programs and accelerated irradiation data. A temperature dependent factor is incorporated for assessing vessel locations operating at different temperatures. As hardening and embrittlement arise from the sum of matrix damage and copper impurity precipitation, the influence of irradiation temperature on each process needs to be established. For irradiations performed below #approx# 300 C recent data shows that the dose-dependent growth of copper precipitates ceases at a mean diameter of about 2 nm that also corresponds to peak hardening and embrittlement by copper. For doses beyond this peak copper dose the property-dependence on irradiation temperature can be identified with that of matrix damage alone. An analysis of several experiments on plate steels, performed at ...

1994-06-20

56

Towards the entropy of gravity time-dependent models via the Cardy-Verlinde formula  

International Nuclear Information System (INIS)

For models with several time-dependent components, generalized entropies can be defined. This is shown for the Bianchi type IX model. We first derive the Cardy-Verlinde formula under the assumption that the first law of thermodynamics is valid. This leads to an explicit expression of the total entropy associated with this type of universe. Assuming the validity of the Cardy entropy formula, we obtain expressions for the corresponding Bekenstein, Bekenstein-Hawking and Hubble entropies. We discuss the validity of the Cardy-Verlinde formula and possible extensions of the outlined procedure to other time-dependent models.

2003-07-15

57

The effect of the shear rate-dependent thermal conductivity of non-Newtonian fluids on the heat transfer in a pipe flow  

Science.gov (United States)

The present study investigates the effect of the shear rate-dependent thermal conductivity of non-Newtonian fluids on the heat transfer enhancement in a pipe flow. The constant heat flux as thermal boundary condition was adopted in the thermally developed region. The present analytical results show the heat transfer enhancement over those of a shear rate-independent thermal conductivity fluid. The heat transfer coefficient ratio (h/h{sub 0}) linearly increase with the non-dimensional average velocity difference which is the product of the shear rate-dependence of the thermal conductivity and wall-shear rate.

1996-09-01

58

Some rotating, time-dependent Bianchi type-IX cosmologies with heat flow  

Energy Technology Data Exchange (ETDEWEB)

Solutions are obtained for the Einstein field equations governing 40 rotating and time-dependent Bianchi type-IX cosmologies with thermal and nonthermal perfectly fluid sources. Some general properties of the solutions are discussed, and the exact computational details are given in a companion paper. All the cosmologies have spacelike, timelike or null-like homogeneous hypersurfaces depending on whether the constant alpha is less than or greater than one. The pressure of the cosmologies is assumed to be zero, and the energy density is less than zero. 9 references.

1985-06-01

59

Simulation of DNA electrophoresis through microstructures  

British Library Electronic Table of Contents (United Kingdom)

The dependence of the mobility of DNA molecules through an hexagonal array of micropillars on their length and the applied electric field was investigated and it was found that mobility is a nonmonotonic function of their length. Results also revealed that the size dependence of the DNA mobility depends on the applied electric field and there is a crossover around E 25 V/cm for the mobility of l-DNA and T4-DNA. These observations are explained in terms of the diffusion process inside the structure affected by the solvent and are modeled using the Langevin and its corresponding Fokker-Planck equations. The phenomenon is generalized under three regimes in a phase diagram relating the electric field and the DNA lengths. The model and the associated phase diagram described here provide an expl...

2007-01-01

60

Production of secondary Deuterium in the atmosphere at various latitudes  

Energy Technology Data Exchange (ETDEWEB)

Secondary deuterium in the atmosphere are produced in interactions by primary cosmic rays. The shape of their energy spectrum depends on the primary cosmic ray spectrum incident at the top of the atmosphere. At high energies, the spectral shape depends on the primary spectrum of helium and heavy nuclei. However, at very low energies, specially below the geomagnetic cut-off, the spectral shape depends on the evaporation and recoil processes and hence almost independent of the spectral shape of the primary radiation. It is undertaken a calculation of the secondary deuterium spectrum at small atmospheric depths at various latitudes and the results will be presented.

1995-09-01

61

Mechanisms of Alloy 800 corrosion in helium  

International Nuclear Information System (INIS)

Cr_2O_3 scales are found to form on Alloy 800 and a similar pure ternary alloy in air, and 1 and 50 atm. helium containing oxidizing impurities typical of those in an SGHTR. The strong temperature dependence and neglibible helium overpressure dependence indicate that gas transport through the scales is not rate controlling. Surface oxidation rates are therefore controlled by solid state diffusion and the low oxygen partial pressure dependence of the oxidation rate in Alloy 800 is ascribed to the presence of extrinsic defects in the Cr_3O_3 (due to doping by alloying elements) or to the presence of short circuit diffusion paths. (Auth.).

62

LET-dependence of the trapping parameters in TLD-100 determined with a computerised curve fitting method  

International Nuclear Information System (INIS)

With a computerized curve fitting method the trapping parameters of TLD-100 chips were calculated after #alpha#-, #beta#- and #gamma#-irradiation. The absorption of radiation produces an additional glow peak at 250 deg C, and the dominant one arises at 280 deg C. After the analysis of the glow curves only a little LET-dependence of the trap depths and that of the half widths was detected. The charge densities after irradiation before heating of the taps responsible for the high temperature glow peaks (T>240 deg C) show a LET-dependence. (author).

1985-10-22

63

Hall mobility minimum of temperature dependence in polycrystalline silicon  

Science.gov (United States)

Molten zone recrystallized as well as sheet grown polycrystalline silicon has shown a minimum in the temperature dependence of the Hall mobility. In order to explain this experimental finding a new model is proposed, which is based on negatively charged grain boundaries for the p-type silicon material under study. This results in a potential well at the grain boundaries instead of the more generally observed potential barrier. A key feature in the model is that the space charge density at the grain boundary depends on the Fermi level position and therefore on temperature. In addition, the change in the measured Hall mobility before and after hydrogen passivation of the grain boundaries is discussed.

1998-01-01

64

Dynamics of a H(n) atom in time-dependent electric and magnetic fields  

International Nuclear Information System (INIS)

The symmetry properties of the Coulomb potential allow for a dynamical spin-1/2 description of any fixed n level of a hydrogenlike atom in a time-dependent sufficiently weak electric and/or magnetic field. An explicit expression for the time dependence of the l,m amplitudes pertaining to a general n level is derived. The derivation follows on purely algebraic operations. Based on the derivation, we give analytical n-independent solutions to established and proposed schemes for driving the atom into a high angular-momentum state.

2002-05-01

65

Dimensionally dependent luminescence of boron difluoride ?-diketonates  

International Nuclear Information System (INIS)

The results of the study of dimensionally dependent fluorescence of boron difluoride ?-diketonates of general formula (R1COCHCOR2)BF2 are presented. The fact that for most of the compounds studied a noticeable hypsochrome shift of the luminescence band maximum is characteristic during transition from bulk crystals to microcrystals was detected. However, for boron difluoride dibenzoylmethanate having a unique supramolecular structure, a bathochromic shift of luminescence due to the crustal size reduction is observed. The dimensionally dependent luminescence properties of the complexes have been analyzed within the exciton mechanism

2008-06-01

66

A dependence of cumulative pion production cross sections in proton-nuclear interactions at high energies  

International Nuclear Information System (INIS)

The A dependence of cumulative pion production yield cross sections on the basis of the comparison of the data on relative pion yields on Be,C,Al,Ti,Mo and W nuclei at the 159 deg angle laboratory system for the incident proton energy E_0 from 25 to 62 GeV is considered. The regular A dependence on cumulative variable X is noted. The results are compared with the data at E_0< 10 GeV. A possible interpretation of the observed behaviour on the basis of the hypothesis of the flucton mechanism of the pion production in the cumulative region is discussed. 15 refs.; 4 figs.

67

ch4  

Science.gov (United States)

Earlier studies had concluded that the preferred direction of the rocket nozzle should ..... Center had to redesign the sensor canisters, brackets and cable supports. ... depending on inspection of the quality of the incoming pictures in real-time. ...

68

Vitamin D and Serum Cytokines in a Randomized Clinical Trial  

UK PubMed Central (United Kingdom)

Background. The role of vitamin D in the body's ability to fight influenza and URI's may be dependent on regulation of specific cytokines that participate in the host inflammatory...Full Text Available

2010-01-01

69

Vehicle-Dependent Disposition Kinetics of Fluoranthene in Fisher-344 Rats  

UK PubMed Central (United Kingdom)

The objective of this study was to evaluate how the vehicles of choice affect the pharmacokinetics of orally administered Fluoranthene [FLA] in rats. Fluoranthene is a member of the family of...Full Text Available

2008-03-01

70

Trial of Seroquel SR for Alcohol Dependence and Comorbid Anxiety  

Science.gov (United States)

Alcoholism; Anxiety Disorders; Generalized Anxiety Disorder; Post-Traumatic Stress Disorder; Panic Disorder; Obsessive-Compulsive Disorder

2008-12-05

71

Time-dependent ARMA modeling of genomic sequences  

UK PubMed Central (United Kingdom)

BackgroundOver the past decade, many investigators have used sophisticated time series tools for the analysis of genomic sequences. Specifically, the correlation of the nucleotide...Full Text Available

72

Time-dependent 3-D dterministic transport on parallel architectures using Dantsys/MPI  

Energy Technology Data Exchange (ETDEWEB)

In addition to the ability to solve the static transport equation, we have also incorporated time dependence into our parallel 3-D S{sub {ital N}} code DANTSYS/MPI. Using a semi-implicit scheme, DANTSYS/MPI is capable of performing time-dependent calculations for both fissioning and pure source driven problems. We have applied this to various types of problems such as nuclear well logging and prompt fission experiments. This paper describes the form of the time- dependent equations implemented, their solution strategies in DANTSYS/MPI including iteration acceleration, and the strategies used for time-step control. Results are presented for a model nuclear well logging calculation.

1996-12-31

73

Time-Dependent Propagation of High-Energy Laser Beams ...  

Science.gov (United States)

... Law Parameter 28 Summary 28 6. CIRCULAR VS ANNULAR LASER BEAMS 29 7. HIGH-ENERGY LASER BEAM PROPAGATION THROUGH A ...

1977-12-14

74

The formation and degradation of Ti-Ag and Ti-Pd-Ag solar cell contacts  

Science.gov (United States)

Ti-Ag and Ti-Pd-Ag solar cell contacts structure and degradation dependence on high temperature and humidity environmental exposure

1970-01-01

75

The Management of Pit Viper Envenomation of the Hand  

UK PubMed Central (United Kingdom)

Snakebites are common among the rural population of developing countries. The severity of venomous snakebites depends on several factors, including the location of the bite, the amount of venom injected,...Full Text Available

2008-12-01

76

Temperature and time-dependence of the elastic moduli of Pu and Pu-Ga alloys  

International Nuclear Information System (INIS)

In previous work, on cooling from 300 K to 10 K the elastic moduli for both #alpha#- and #delta#-Pu dropped 30%. This large change may reflect effects of 5f-electron localization. In this work, the elastic moduli at ambient temperature of several Pu-Ga alloys were measured using resonant ultrasound spectroscopy (RUS). The strong temperature dependence of the bulk and shear modulus and the temperature independence of Poisson's ratio was confirmed and the upper temperature limit for #alpha#-Pu was extended to 360 K. Measurements of the time dependence of the shear moduli of Pu and Pu-2.36 at.% Ga were determined with high precision as a function of time and temperature. Using a model for time dependence of point defects, we determined the exponential time constant at ambient temperature for such variations. The low temperature results are consistent with Fluss .

2007-10-11

77

Strain-dependent variation in collateral circulatory function in mouse hindlimb  

UK PubMed Central (United Kingdom)

The extent (density and diameter) of the native (preexisting) collateral circulation in healthy tissues and the capacity of collaterals to enlarge/remodel in obstructive arterial disease are important...Full Text Available

2010-08-01

78

Search Results - NASA Technical Reports Server  

Science.gov (United States)

The influence of ablation on stagnation region convective heating for ... and thermal properties of this fiber depend on the fluorination process ... However, these properties are between those of graphite and those of PTFE (Teflon). ...

79

STUDY OF FAILURE AND RELIABILITY IN MICROELECTRONIC DEVICES 3rd ...  

Science.gov (United States)

It is well known that the growth of purple plague is tempera- ture dependent. in Figure 2 which shows the progressive growth of purple ...

80

Response to CRH Infusion in Cocaine-Dependent Individuals  

UK PubMed Central (United Kingdom)

ContextCorticotropin-releasing hormone (CRH), through the hypothalamic pituitary adrenal (HPA) axis and other brain stress systems, is involved in the emotional dysregulation...Full Text Available

2009-04-01

81

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

CERN Document Server

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

2011-01-01

82

Production of Amylase in Liquid Culture by a Strain of Aspergillus oryzae  

UK PubMed Central (United Kingdom)

The effect of different media and pH on the formation of amylase by Aspergillus oryzae EI 212 is described. Depending upon the composition of the medium and growth...Full Text Available

1970-04-01

83

Principles of antibody therapy.  

UK PubMed Central (United Kingdom)

The success of monoclonal antibodies in clinical practice is dependent on good design. Finding a suitable target is the most important part as other properties of the antibody can be altered by genetic...Full Text Available

1992-12-05

84

Prevalence-Dependent Costs of Parasite Virulence  

UK PubMed Central (United Kingdom)

Costs of parasitism are commonly measured by comparing the performance of infected groups of individuals to that of uninfected control groups. This measure potentially underestimates the cost of parasitism...Full Text Available

2005-08-01

85

Predation and fragmentation portrayed in the statistical structure of prey time series  

UK PubMed Central (United Kingdom)

BackgroundStatistical autoregressive analyses of direct and delayed density dependence are widespread in ecological research. The models suggest that changes in ecological factors...Full Text Available

86

Peritonectomy procedures.  

UK PubMed Central (United Kingdom)

OBJECTIVE: New surgical procedures designed to assist in the treatment of peritoneal surface malignancy were sought. BACKGROUND: Decisions regarding the treatment of cancer depend on the anatomic location...Full Text Available

1995-01-01

87

On the Z-dependence of K#alpha#_1/K#beta#_1 X-ray intensity ratio  

International Nuclear Information System (INIS)

1976. Germany Ramaswamy, MK Birla Inst. of Tech. and Science, Pilani

1976-03-29

88

OHCM QUESTION AND ANSWERING SYSTEM  

Science.gov (United States)

Jun 6, 2011... applied first (depending upon whether the employee is exempt or non-exempt) before applying the provisions of compensatory time travel. ...

89

Numerical Simulation of Cirrus Clouds - Fire Case Study and ...  

Science.gov (United States)

... being pulled out of water, the movement is restricted ... This heating depended on the particle size ... hydrometeor injection into the upper tropopause. ...

1991-08-12

90

Multifractal Analysis of Multiple Ergodic Averages  

CERN Document Server

In this paper we present a complete solution to the problem of multifractal analysis of multiple ergodic averages in the case of symbolic dynamics for functions of two variables depending on the first coordinate.

2011-01-01

91

Modeling of phosphorus diffusion in Ge accounting for a cubic dependence of the diffusivity with the electron concentration  

International Nuclear Information System (INIS)

Up to now, P diffusion in Ge is modeled with an effective diffusivity involving at most a quadratic dependence with the free electron concentration (n). However, recent theoretical studies suggest the existence of a triply negatively charged state for the free vacancy in germanium and experimental data indicate that the E center (PV pair) in Ge has a double acceptor state. These two facts would be consistent with a diffusivity model involving a cubic dependence with n. In this paper the validity of this approach is checked for both pure thermal diffusion (intrinsic and extrinsic) and implanted phosphorus, using either our own experiments or other data available from the literature. Although some discrepancies still exist in some cases for the redistribution of implanted P, it is shown that the introduction of this cubic dependence significantly improves the overall agreement as compared with the usual model.

2010-02-26

92

Mirtazapine for patients with alcohol dependence and comorbid depressive disorders: A multicentre, open label study  

British Library Electronic Table of Contents (United Kingdom)

Major depressive disorder and alcohol dependence are common and serious mental illnesses. There is a great interest in discovering useful treatments for both mood symptoms and alcohol abuse in those patients with depressive disorders and comorbid alcohol dependence. The primary purpose of this study was to evaluate the effectiveness and tolerability of mirtazapine for the treatment of patients with alcohol dependence comorbid with a depressive disorder in an open label, naturalistic multicentre treatment setting. The 17-item Hamilton Depression Rating Scale (HDRS), the Hamilton Anxiety Rating Scale (HARS) and the Clinical Global Impression-Severity (CGI-S) scale were measured at baseline and at weeks 4 and 8 for the assessment of treatment effectiveness. Alcohol craving was measured using ...

2006-01-01

94

Hyaluronan-Dependent Pericellular Matrix  

UK PubMed Central (United Kingdom)

Hyaluronan is a multifunctional glycosaminoglycan that forms the structural basis of the pericellular matrix. Hyaluronan is extruded directly through the plasma membrane by one of three hyaluronan...Full Text Available

2007-11-10

95

Gpnmb is a Melanoblast-Expressed, MITF-Dependent Gene  

UK PubMed Central (United Kingdom)

SUMMARYExpression profile analysis clusters Gpnmb with known pigment genes, Tyrp1, Dct, and Si. During development,...Full Text Available

2009-02-01

96

Development work currently being carried out on the time-dependent finite-element diffusion code TRANSFUSION for nuclear oil well logging problems  

Energy Technology Data Exchange (ETDEWEB)

The code is being developed starting from the steady-state finite element code FENDER for the solution of the diffusion equation by extending it to become time-dependent. The numerical solution of the time-dependent multigroup diffusion equations within TRANSFUSION is performed at the present stage of development by using a backward difference scheme for the time variable, leading to a rearrangement of FENDER by adding a new loop over time steps. The code retains the multigroup coupled neutron-gamma features of FENDER, and provides a consistent two-, and quasi three-dimensional numerical solution of both static and time-dependent multigroup diffusion equations. (orig./DG)

1993-04-01

99

Cobalamin- and Corrinoid-Dependent Enzymes  

UK PubMed Central (United Kingdom)

This chapter will review the literature on cobalamin- and corrinoid-containing enzymes. These enzymes fall into two broad classes, those using methylcobalamin or related methylcorrinoids as...Full Text Available

2009-01-01

100

Can you count on computers?  

CERN Document Server

"Machines of all kinds depend on complex software to keep them operating safely. But how reliable is the software - and how can we be sure it is reliable?" (4 pages)

1989-01-01

101

Behavior of osteoblastic cells cultured on titanium and structured zirconia surfaces  

UK PubMed Central (United Kingdom)

BackgroundOsseointegration is crucial for the long-term success of dental implants and depends on the tissue reaction at the tissue-implant interface. Mechanical properties and biocompatibility...Full Text Available

103

Angular dependence from L_3-subshell to M-shell vacancy transfer probabilities for heavy elements using EDXRF technique  

International Nuclear Information System (INIS)

Angular dependence from L_3-subshell to M-shell vacancy transfer probabilities for selected heavy elements from Au to U have been measured by using a Si(Li) detector coupled to a model 1024 computerized multi-channel analyzer. Because the angular dependence from L_3-subshell to M-shell vacancy transfer probabilities is not found in the literature, to the best of our knowledge there are no experimental values for worked elements. Therefore, the results for the elements obtained in the present study constitute the first experimental measurements; the comparison has been not made with other experimental and theoretical results. It has been observed that angular dependence from L_3-subshell to M-shell vacancy transfer probabilities increase with increasing cos #theta#.

2008-07-01

104

Alpha/Beta Heat Treatment of a Titanium Alloy with a Non ...  

Science.gov (United States)

... transformed at 705°C. The cooling rate and temperature dependence of matrix decomposition for Ti6242 was thus similar to that for Ti64 x [9]. ...

2006-08-01

105

Accidental ingestion of 35% hydrogen peroxide  

UK PubMed Central (United Kingdom)

Hydrogen peroxide is a commonly used oxidizing agent with a variety of uses depending on its concentration. Ingestion of hydrogen peroxide is not an uncommon source of poisoning, and results in morbidity...Full Text Available

2007-10-01

106

8 - NASA Technical Reports Server  

Science.gov (United States)

The influence of ablation on stagnation region convective heating for ... and thermal properties of this fiber depend on the fluorination process ... However, these properties are between those of graphite and those of PTFE (Teflon). ...

107

Wavelength dependence of the threshold in an InGaP-InAlGaP vertical cavity surface emitting laser  

Energy Technology Data Exchange (ETDEWEB)

The wavelength dependence of the threshold in an InGaP-InAlGaP vertical cavity surface emitting laser is investigated using a microscopic theory of the semiconductor gain medium. Good agreement is found between experiment and theory for the minimum threshold lasing wavelength for a range of laser structures.

1994-07-11

108

Wavelength dependence of the threshold in an InGaP-InAlGaP vertical cavity surface emitting laser  

International Nuclear Information System (INIS)

The wavelength dependence of the threshold in an InGaP-InAlGaP vertical cavity surface emitting laser is investigated using a microscopic theory of the semiconductor gain medium. Good agreement is found between experiment and theory for the minimum threshold lasing wavelength for a range of laser structures.

109

Tunneling spectroscopy of anisotropic superconductors  

Energy Technology Data Exchange (ETDEWEB)

Tunneling spectroscopy of normal-insulator-superconductor junction is investigated theoretically. In anisotropic superconductors, differently from the case of isotropic superconductor, the effective pair potentials felt by quasiparticles depend on the direction of their motion. By taking this effect into account, it is shown that the conductance spectra strongly depend on the crystal orientation. Using Green`s function method, local density of states (LDOS) in superconductor is also calculated. The close relation between conductance spectra and LDOS is presented. The calculation is compared with experimental spectra of high-{Tc} superconductors.

1996-12-31

110

Transcription of the E2F-1 gene is rendered cell cycle dependent by E2F DNA-binding sites within its promoter.  

UK PubMed Central (United Kingdom)

The cell cycle-regulatory transcription factor E2F-1 is regulated by interactions with proteins such as the retinoblastoma gene product and by cell cycle-dependent alterations in E2F-1 mRNA abundance....Full Text Available

1994-10-01

111

The synthetic substrate succinyl(carbadethia)-CoA generates cob(II)alamin on adenosylcobalamin-dependent methylmalonyl-CoA mutase.  

UK PubMed Central (United Kingdom)

Succinyl(carbadethia)-coenzyme A, a synthetic substrate for adenosylcobalamin-dependent methylmalonyl-CoA mutase, has been prepared by a simplified procedure. When recombinant mutase was mixed with...Full Text Available

1993-10-15

112

The brain-derived neurotrophic factor Val66Met polymorphism is associated with reduced functional magnetic resonance imaging activity in the hippocampus and increased use of caudate nucleus-dependent strategies in a human virtual navigation task  

UK PubMed Central (United Kingdom)

Multiple memory systems are involved in parallel processing of spatial information during navigation. A series of studies have distinguished between hippocampus-dependent ‘spatial’ navigation,...Full Text Available

2011-03-01

113

The Isolation and Characterization of d-Glucose 6-Phosphate Cycloaldolase (NAD-Dependent) from Acer pseudoplatanus L. Cell Cultures  

UK PubMed Central (United Kingdom)

A soluble enzyme system from suspension cultures of Acer pseudoplatanus L. converts d-glucose 6-phosphate to myoinositol. A Mg2+-dependent phosphatase, present in...Full Text Available

1971-09-01

114

Superconducting properties and structural transition in compounds with an A-15 lattice  

International Nuclear Information System (INIS)

The dependence of Tsub(c) on composition and deformation is calculated and compared with the corresponding dependence for Tsub(m). It is shown that superconducting and structural properties of A-15 compounds can be described, at least qualitatively, by the quasi-one-dimensional model previously developed by the authors. The superconductivity mechanism is assumed to be analogous to the BCS theory. The upper critical field Hsub(c2) of the V_3Si or Nb_3Sn compounds is found to be much greater than that in V or Nb.

115

Structure functions of nuclei in the flucton model with rescaling  

Energy Technology Data Exchange (ETDEWEB)

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

1987-02-01

116

Structure functions of nuclei in the flucton model with rescaling  

International Nuclear Information System (INIS)

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

117

Radiation-annealing hardening of vanadium  

International Nuclear Information System (INIS)

Mechanical properties of vanadium, irradiated with fast neutrons up to 8.6x10"-"4 dpa depending on postirradiation annealing temperature, are studied. It is shown that radiation-annealing hardening (RAH) is observed at 300 deg C, which agrees with earlier performed studies. It is first stated that RAH is accompanied by plasticity decrease. Phenomenological model permitting to explain RAH dependence on irradiation temperature and dose and also on content of chemically active alloying impurities is suggested.

118

Protein dynamics. Vibrational coupling, spectral broadening mechanisms, and anharmonicity effects in carbonmonoxy heme proteins studied by the temperature dependence of the Soret band lineshape.  

UK PubMed Central (United Kingdom)

In this work we study the temperature dependence of the Soret band lineshape of the carbonmonoxy derivatives of sperm whale myoglobin, human hemoglobin, and its isolated alpha and beta subunits. To...Full Text Available

1992-08-01

119

Pore size distribution in ZrO_2-Al_2O_3 composite particles prepared from Zr-Al metallo-organic compounds  

International Nuclear Information System (INIS)

Zr-Al metallo-organic compounds were thermally decomposed to prepare ZrO_2-Al_2O_3 composite powders. The specific surface area was dependent on the organofunctional groups of the starting organic compounds. The pore size distribution was dependent on the heating rate when the heating temperature was the same. 4 refs.; 4 figs.

1989-01-01

120

Modeling dependent failures for the availability of extra high voltage transmission lines  

Energy Technology Data Exchange (ETDEWEB)

This paper investigates the calculation of availability for parallel transmission lines (two or more) in the same tower or on the same right of way. As in many studies, the development of mathematical models is an important step. The models are justified using historical data and known characteristics of power system elements. A statistical method was used to generalize the failure rate and repair rate from real operating data. Application of the new model (which combines common-mode, simultaneous independent, and dependent outages) is discussed.

1989-06-01

121

Light emission from grazing incidence interaction of light ions with clean Cu(110)  

International Nuclear Information System (INIS)

Photon yields were measured from Cu(110) bombarded by H"+, H_2"+ and He"+ with different energies. The energy dependence is different from previous studies at perpendicular incidence. A calculation of the energy dependence of resonant charge capture into the n=3 state of H is compared with experiment. (G.Q.).

1983-02-04

122

Interactions between heavy mesons and Goldstone bosons from chiral dynamics  

Energy Technology Data Exchange (ETDEWEB)

We calculate the S-wave scattering lengths for charmed mesons scattering off Goldstone bosons and explore their quark mass dependence using the chiral perturbation theory up to next-to-leading order as well as a unitarized version of it. The quark mass dependence of all scattering lengths determined in a recent lattice calculation can be reproduced by the unitarized version. We also discuss signals of possible bound states in these observables. (orig.)

2009-05-15

123

Hepatitis C Virus RNA Replication Requires a Conserved Structural Motif within the Transmembrane Domain of the NS5B RNA-Dependent RNA Polymerase ?  

UK PubMed Central (United Kingdom)

Hepatitis C virus (HCV) nonstructural protein 5B (NS5B), the viral RNA-dependent RNA polymerase (RdRp), is a tail-anchored protein with a highly conserved C-terminal transmembrane domain (TMD) that...Full Text Available

2010-11-01

124

Geometrically relating momentum cut-off and dimensional regularization  

CERN Document Server

The $\\beta$ function for a scalar field theory describes the dependence of the coupling constant on the renormalization mass scale. This dependence is affected by the choice of regularization scheme. I explicitly relate the $\\beta$-functions of momentum cut-off regularization and dimensional regularization on scalar field theories by a gauge transformation using the Hopf algebras of the Feynman diagrams of the theories.

2011-01-01

125

Gas-temperature-dependent generation of cryoplasma jet under atmospheric pressure  

International Nuclear Information System (INIS)

Plasma with a gas temperature below room temperature is not yet fully understood although it is expected to be an attractive tool for applications to material processing. In the present work, gas-temperature-dependent generation of a cryoplasma jet was studied. So far, we have generated a helium cryoplasma jet (296-5 K) under atmospheric pressure. At gas temperatures below 20 K, the helium excimer, He2, was observed clearly from by optical emission spectroscopy.

2008-09-08

126

Enhanced glycemic responsiveness to epinephrine in insulin-dependent diabetes mellitus is the result of the inability to secrete insulin. Augmented insulin secretion normally limits the glycemic, but not the lipolytic or ketogenic, response to epinephrine in humans.  

UK PubMed Central (United Kingdom)

To determine if the enhanced glycemic response to epinephrine in patients with insulin-dependent diabetes mellitus (IDDM) is the result of increased adrenergic sensitivity per se, increased glucagon...Full Text Available

1985-06-01

127

Energy dependence of Ksub(#beta#)/Ksub(#alpha#) intensity ratio of Si0_2 from proton induced ionisation  

International Nuclear Information System (INIS)

The Ksub(#beta#)/Ksub(#alpha# 12) x-ray intensity ratio of the Si K spectrum was measured for proton impact on Si0_2 in the energy range 300-800 keV. An energy dependence of the intensity ratio was found and an explanation is given in terms of multiple ionisation. (author).

1980-04-01

128

Effect of rapid thermal annealing on radiation hardening of MOS devices  

International Nuclear Information System (INIS)

The influence of RTA (Rapid Thermal Anneal) treatment on MOS radiation hardness is demonstrated and compared with classical furnace treatment. In the case of the RTA, the oxide trapped charge is found to depend on: (i) the anneal temperature as expected, data are in good agreement with a recently developed model of oxygen out-diffusion; (ii) the location across the wafer with a radial dependence, results could be related to stress induced by thermal gradient.

1995-07-17

129

Earth Matter Effects in Detection of Supernova Neutrinos  

CERN Document Server

We calculated the matter effect, including both the Earth and supernova, on the detection of neutrinos from type II supernovae at the proposed Daya Bay reactor neutrino experiment. It is found that apart from the dependence on the flip probability P_H inside the supernova and the mass hierarchy of neutrinos, the amount of the Earth matter effect depends on the direction of the incoming supernova neutrinos, and reaches the biggest value when the incident angle of neutrinos is around 93^\\circ. In the reaction channel \\bar{\

2006-01-01

130

Depth of origin of the gas content in thermal waters  

Energy Technology Data Exchange (ETDEWEB)

The gas composition of recent thermal waters is in perfect conformity with their geologic-tectonic positions. The composition of gas-liquid inclusions in the basic-hyperbasic xenoliths of basaltoid lavas depends on the depth from which xenoliths are supplied. (The depth is determined by using the methods of geological thermobarometers). By comparing available data the conclusion was drawn that the gas compositions of thermal waters reflect the depth of generation of deep fluid which heats them and depends on the penetration depth of the fluid-conducting fissure zones.

1980-01-01

131

Contribution of surface rayleigh waves to the heat capacity of poly(vinyl chloride)  

British Library Electronic Table of Contents (United Kingdom)

The method of surface acoustic waves is employed to determine the frequency and temperature dependences of the molar heat capacity of poly(vinyl chloride) on the contribution of Rayleigh local components of the longitudinal and transverse vibrations of structural units of the polymer. The calculated and experimental data are compared in terms of their dependence on the relaxation state of the system.

2009-01-01

132

Canonical and Alternative Pathways in Cyclin-Dependent Kinase 1/Cyclin B Inactivation upon M-Phase Exit in Xenopus laevis Cell-Free Extracts  

UK PubMed Central (United Kingdom)

Cyclin-Dependent Kinase 1 (CDK1) is the major M-phase kinase known also as the M-phase Promoting Factor or MPF. Studies performed during the last decade have shown many details of how CDK1 is regulated...Full Text Available

133

Calculation of the temperature dependence of the phonon spectrum of Nb/sub 3/Sn  

Energy Technology Data Exchange (ETDEWEB)

With the help of the symmetry at the P point, we have determined the relations between the force constants and the moduli of elasticity for A-15 compounds. Based on these relations, a semi-experimental method for the study of the lattice dynamic behaviors of A-15 compounds is developed. Numerical calculations of the phonon spectrum of Nb/sub 3/Sn and its temperature dependence have been made, and they are in good agreement with the experimental data.

1986-12-01

134

Basis for the Specificity and Activation of the Serpin Protein Z-dependent Proteinase Inhibitor (ZPI) as an Inhibitor of Membrane-associated Factor Xa*  

UK PubMed Central (United Kingdom)

The serpin ZPI is a protein Z (PZ)-dependent specific inhibitor of membrane-associated factor Xa (fXa) despite having an unfavorable P1 Tyr. PZ accelerates the inhibition reaction ∼2000-fold...Full Text Available

2010-06-25

135

A structure modeling of metal-silicide layers by using axial and planar channeling techniques  

International Nuclear Information System (INIS)

Planar channeling effects are studied in such well-oriented polycrystalline layers as NiSi_2 and Pb_2Si layers formed on single crystalline Si. Crystalline perfection of such layers is discussed by using the energy- and angular dependences of the axial and planar channeling yields. It has been shown that, in suitable conditions, the energy dependence of the planar yield is more sensitive to the spread of crystallite orientations in polycrystals than that of the axial one. (Auth.).

136

No Generalized TMD-Factorization in Hadro-Production of High Transverse Momentum Hadrons  

CERN Document Server

It has by now been established that standard QCD factorization using transverse momentum dependent parton distribution functions fails in hadro-production of nearly back-to-back hadrons with high transverse momentum. The essential problem is that gauge invariant transverse momentum dependent parton distribution functions cannot be defined with process-independent Wilson line operators, thus implying a breakdown of universality. This has led naturally to proposals that a correct approach is to instead use a type of "generalized" transverse momentum dependent factorization in which the basic factorized structure is assumed to remain valid, but with transverse momentum dependent parton distribution functions that contain non-standard, process dependent Wilson line structures. In other words, to recover a factorization formula, it has become common to assume that it is sufficient to ...

2010-01-01

137

Light meson mass dependence of the positive-parity heavy-strange mesons  

Energy Technology Data Exchange (ETDEWEB)

We calculate the masses of the resonances D{sub s0}{sup *}(2317) and D{sub s1}(2460) as well as their bottom partners as bound states of a kaon and a D{sup (*)} - and B{sup (*)} -meson, respectively, in unitarized chiral perturbation theory at next-to-leading order. After fixing the parameters in the D{sub s0}{sup *}(2317) channel, the calculated mass for the D{sub s1}(2460) is found in excellent agreement with experiment. The masses for the analogous states with a bottom quark are predicted to be M{sub B{sup *}{sub s0}}=(5696{+-}40) MeV and M{sub B{sub s1}}=(5742{+-}40) MeV in reasonable agreement with previous analyses. In particular, we predict M{sub B{sub s1}}-M{sub B{sub s0}}{sup *}=46{+-}1 MeV. We also explore the dependence of the states on the pion and kaon masses. We argue that the kaon mass dependence of a kaonic bound state should be almost linear with slope about unity. Such a dependence is specific to the ...

2011-02-15

138

A dip-dependent divergence correction  

Energy Technology Data Exchange (ETDEWEB)

A divergence correction is conventionally applied to zero-offset data in an effort to preserved amplitude information. The conventional divergence correction compensates for the geometrical spreading of a point source in a horizontally layered medium where velocity varies with depth only. The dip-dependent divergence correction extends the conventional correction for improved amplitude processing of dipping beds. The dip-dependent divergence correction is computed by dynamic ray tracing, and applied to stacked data using a dip decomposition technique. This correction decreases amplitudes relative to the conventional correction for steep dips and late times. In a data example from the Gulf of Mexico, the conventional correction over- amplified the reflection off a salt dome flank by a factor of 1.6. High amplitudes near salt flanks are also associated with the presence of hydrocarbons. Applying the dip-dependent divergence ...

1992-01-01

139

A dip-dependent divergence correction  

Energy Technology Data Exchange (ETDEWEB)

A divergence correction is conventionally applied to zero-offset data in an effort to preserved amplitude information. The conventional divergence correction compensates for the geometrical spreading of a point source in a horizontally layered medium where velocity varies with depth only. The dip-dependent divergence correction extends the conventional correction for improved amplitude processing of dipping beds. The dip-dependent divergence correction is computed by dynamic ray tracing, and applied to stacked data using a dip decomposition technique. This correction decreases amplitudes relative to the conventional correction for steep dips and late times. In a data example from the Gulf of Mexico, the conventional correction over- amplified the reflection off a salt dome flank by a factor of 1.6. High amplitudes near salt flanks are also associated with the presence of hydrocarbons. Applying the dip-dependent divergence ...

1992-07-01

140

Correlation between proton pumping and the bacteriorhodopsin photocycle  

Energy Technology Data Exchange (ETDEWEB)

In an attempt to establish a relationship between proton pumping and the photocycle intermediates of bacteriorhodopsin, we have studied the effects of pH and temperature of flash-induced proton pumping and the photointermediates O/sub 640/ and M/sub 412/. The relative quantum yield of flash-induced proton pumping is both pH and temperature dependent. It is high in the acid pH range and at low temperatures but decreases in the basic pH range and at high temperatures. The decay of M/sub 412/ is biphasic. The amplitude of the slowly decaying component (M/sup s/) was found to be pH dependent with a pK similar to that of the ..delta..pH. The pH dependence of the fast-decaying component (M/sup f/) is opposite to that of M/sup s/ and ..delta..pH. Like that of M/sup s/, the amplitude of O/sub 640/ is high in the acid pH range, but unlike the amplitude of M/sup s/, it declines very rapidly at pHs greater than 6.5; the amplitude of ...

1984-11-01

141

Tungsten Effects on Phosphate-Dependent Biochemical Pathways are Species and Liver Cell Line Dependent  

British Library Electronic Table of Contents (United Kingdom)

Tungsten, in the form of tungstate, polymerizes with phosphate, and as extensive polymerization occurs, cellular phosphorylation and dephosphorylation reactions may be disrupted, resulting in negative effects on cellular functions. A series of studies were conducted to evaluate the effect of tungsten on several phosphate-dependent intracellular functions, including energy cycling (ATP), regulation of enzyme activity (cytosolic protein tyrosine kinase [cytPTK] and tyrosine phosphatase), and intracellular secondary messengers (cyclic adenosine monophosphate [cAMP]). Rat noncancerous hepatocyte (Clone-9), rat cancerous hepatocyte (H4IIE), and human cancerous hepatocyte (HepG2) cells were exposed to 1-1000 mg/l tungsten (in the form of sodium tungstate) for 24 h, lysed, and analyzed for the ab...

2010-01-01

142

Theoretical analysis of the DC electromagnetic flow coupler  

Energy Technology Data Exchange (ETDEWEB)

A descriptive model and design procedure for the DC electromagnetic flow coupler is developed based on a quasi-one-dimensional analysis previously developed for the DC electromagnetic pump. It is shown that for a particular flow coupler geometry, the total efficiency and the pressure gradients through the pump and generator depend on two parameters - the Hartmann number and the ratio of the pump flow rate to generator flow rate. Thus, for a fixed Hartmann number the efficiency depends only on the flow ratio. However, for a fixed pressure rise through the pump it is shown that the efficiency depends only on the Hartmann number. Nomographs showing the operating characteristics and critical design points are presented. Example calculations for a full-size unit, suitable for use in a liquid-metal cooled fast breeder reactor, are also discussed using the design nomographs.

1983-03-01

143

The mass dependence of the signal peak height of a Bragg-curve ionization chamber  

International Nuclear Information System (INIS)

The Bragg-curve detector of the parallel plate ionization chamber type generates a signal that is a distorted replica of the original Bragg-curve. In result of this distortion, the signal peak height is not only a function of the atomic number of the heavy ion, as it is often stated, but also of the particle mass. This mass effect was studied with the aid of computer simulation, and it was found to be dependent on the Frisch grid to anode gap width and on the detector gas. The charge resolution of the detector is affected very significantly by this mass dependence of the signal peak height. Therefore, a careful selection of the detector gas and the grid to anode gap width is necessary, if good charge resolution over a wide range of heavy ions is required. (orig.).

144

The dependence of the temperature of crystal-liquid phase transition on the size and shape of simple nanocrystal  

British Library Electronic Table of Contents (United Kingdom)

The dependence of melting temperature T m on the size and shape of an n -dimensional nanocrystal of elementary single-component substance is studied. The nanocrystal has the form of an n-dimensional parallelepiped with a square base. The ratio of the length of side rib to the length of base rib (which is equal to f) defines the form of the system. It is demonstrated that, if the surface pressure is ignored, the value of T m decreases with isomorphic (f = const) decrease in the size of nanocrystal. In so doing, the more the value of form parameter f deviates from unity, the more appreciable the size dependence of T m will be. However, if the surface pressure (?Laplace pressure??) is taken into account in the case of decrease in size, the value of T m may vary significantly. In so doing, if ...

2009-01-01

145

Spin-dependent potentials in the linearized collective Schroedinger equation for nuclear quadrupole vibrations  

Energy Technology Data Exchange (ETDEWEB)

The linearized collective Schroedinger equation for nuclear quadrupole surface vibrations incorporates a new spin degree of freeedom with a spin value of 3/2. We use this equation to describe the low energy spectrum of certain even-odd Ir nuclei which have a spin 3/2 in their ground state. For that purpose we explicitly introduce collective spin-dependent potentials which simulate the interaction of the valence nucleon with the core. The linearized Schroedinger equation is transformed into an effective Schroedinger equation with collective spin-dependent potentials. Already collective spin-orbit couplings of SO(3) and SO(5) type are sufficient to reproduce the lowest excited states of even-odd Ir nuclei. (orig.).

1990-06-01

146

Spin-dependent potentials in the linearized collective Schroedinger equation for nuclear quadrupole vibrations  

International Nuclear Information System (INIS)

The linearized collective Schroedinger equation for nuclear quadrupole surface vibrations incorporates a new spin degree of freeedom with a spin value of 3/2. We use this equation to describe the low energy spectrum of certain even-odd Ir nuclei which have a spin 3/2 in their ground state. For that purpose we explicitly introduce collective spin-dependent potentials which simulate the interaction of the valence nucleon with the core. The linearized Schroedinger equation is transformed into an effective Schroedinger equation with collective spin-dependent potentials. Already collective spin-orbit couplings of SO(3) and SO(5) type are sufficient to reproduce the lowest excited states of even-odd Ir nuclei. (orig.).

147

Rate of egg maturation in marine turtles exhibits -universal temperature dependence-  

British Library Electronic Table of Contents (United Kingdom)

Summary 1.-The metabolic theory of ecology (MTE) predicts that, after correcting for body mass variation among organisms, the rates of most biological processes will vary as a universal function of temperature. However, empirical support for -universal temperature dependence- (UTD) is currently equivocal and based on studies of a limited number of traits. 2.-In many ectothermic animals, the rate at which females produce mature eggs is temperature dependent and may be an important factor in determining the costs of reproduction. 3.-We tested whether the rate of egg maturation in marine turtles varies with environmental temperature as predicted by MTE, using the time separating successive clutches of individual females to estimate the rate at which eggs are formed. We also assessed the pheno...

2011-01-01

148

Mass dependence of the signal peak height of a Bragg-curve ionization chamber  

Energy Technology Data Exchange (ETDEWEB)

The Bragg-curve detector of the parallel plate ionization chamber type generates a signal that is a distorted replica of the original Bragg-curve. In result of this distortion, the signal peak height is not only a function of the atomic number of the heavy ion, as it is often stated, but also of the particle mass. This mass effect was studied with the aid of computer simulation, and it was found to be dependent on the Frisch grid to anode gap width and on the detector gas. The charge resolution of the detector is affected very significantly by this mass dependence of the signal peak height. Therefore, a careful selection of the detector gas and the grid to anode gap width is necessary, if good charge resolution over a wide range of heavy ions is required.

1985-01-01

149

Magnetospheric particle acceleration and X-ray emission of pulsars  

CERN Document Server

The available data on isolated X-ray pulsars, their wind nebulae, and the supernova remnants which are connected to some of these sources are analyzed. It is shown that electric fields of neutron stars tear off charged particles from the surface of neutron star and trigger the acceleration of particles. The charged particles are accelerated mainly in the field of magneto-dipole radiation wave. Power and energy spectra of the charged particles depend on the strength of the magneto-dipole radiation. Therefore, the X-ray radiation is strongly dependent on the rate of rotational energy loss and weakly dependent on the electric field intensity. Coulomb interaction between the charged particles is the main factor for the energy loss and the X-ray spectra of the charged particles.

2007-01-01

150

J/Psi dissociation in parity-odd bubbles  

CERN Document Server

We calculate the quarkonium dissociation rate in the P and CP-odd domains (bubbles) that were possibly created in heavy-ion collisions. In the presence of the magnetic field produced by the valence quarks of colliding ions, parity-odd domains generate electric field. Quarkonium dissociation is the result of quantum tunneling of quark or antiquark through the potential barrier in this electric field. The strength of the electric field in the quarkonium comoving frame depends on the quarkonium velocity with respect to the background magnetic field. We investigate momentum, electric field strength and azimuthal dependence of the dissociation rate. Azimuthal distribution of quarkonia surviving in the electromagnetic field is strongly anisotropic; the form of anisotropy depends on the relation between the electric and magnetic fields and quarkonium momentum. These features can be used to explore the properties of the ...

2011-01-01

151

Innovative Elektrizit?tsversorgungssysteme f?r IKT  

British Library Electronic Table of Contents (United Kingdom)

Summary Modern society all over the world depends on information and communication technology (ICT); and security of supply with ICT is an important location factor. In times of increasing anonymity, which makes us more and more dependent on public services such as emergency supports (emergency organizations), communication is existential. Communication also plays an important role for a good functioning of economy and industry, in the course of shorter production and storage times. The usage of ICT is taken for granted. However, the modern society's use of ICT is profoundly dependent on the public power supply. Particularly in highly industrialized countries like e.g. Austria, the ICT sector requires about 10% of the total electric energy demand. One third of these 10% is estimated to be ...

2010-01-01

152

Influence of the X-ray radiation on the lifetime of carriers in the p-n junctions of Si and Ge  

International Nuclear Information System (INIS)

Lifetime of minority charae carriers in the Si and Ge p-n unctions has been measured by pulse method of conductivity modulation of base. Its dependence on the X-ray radiation dose has been investigated. Dependence of current transmission coefficients on the dose has been measured and their sharp decrease at low doses and the following saturation at high doses have been observed. Linear dependence of lifetime on X-ray radiation dose has been obtained. Resulting from the comparison of regularities of the change of lifetime due to current characteristics, it has been shown that X-ray radiation leads to the formation of the surface defects, influencing the change of current characteristics as well as to stationary structural defects, causing the decrease of lifetime of the charge carriers with the increase of X-ray radiation dose.

153

Grain size effects on the tensile properties and deformation mechanisms of a magnesium alloy, AZ31B, sheet  

International Nuclear Information System (INIS)

The grain size dependence of the tensile properties and the deformation mechanisms responsible for those properties are examined for Mg alloy, AZ31B, sheet. Specifically, the Hall-Petch effect and strain anisotropy (r-value) are characterized experimentally, and interpreted using polycrystal plasticity modeling. {1 0 . 2} extension twins, {1 0 . 1} contraction twins, and so-called 'double-twins' are observed via microscopy and diffraction-based techniques, and the amount of twinning is found to increase with increasing grain size. For the sheet texture and tensile loading condition examined, {1 0 . 2} extension twinning is not expected, yet the polycrystal plasticity model predicts the observed behavior, including this 'anomalous' tensile twinning. The analysis shows that the Hall-Petch strength dependence, of the polycrystal as a whole, is primarily determined by the grain size dependence of the strength of the prismatic ...

2008-07-15

154

Geothermal Casimir Phenomena  

CERN Document Server

We present first worldline numerical results for the nontrivial interplay between geometry and temperature dependencies of the Casimir effect. We show that the temperature dependence of the Casimir force can be significantly larger for open geometries (e.g., perpendicular plates) than for closed geometries (e.g., parallel plates). For surface separations in the experimentally relevant range, the thermal correction for the perpendicular-plates configuration exhibits a stronger parameter dependence and exceeds that for parallel plates by more than an order of magnitude at room temperature. This effect can be attributed to the fact that the fluctuation spectrum for closed geometries is gapped, inhibiting the thermal excitation of modes at low temperatures. By contrast, open geometries support a thermal excitation of the low-lying modes in the gapless spectrum already at low temperatures.

2007-01-01

155

Experimental determination of a species-dependent effect in the transverse emittances of sputter-generated negative-ion beams  

Energy Technology Data Exchange (ETDEWEB)

We report experimental evidence of a previously unseen species-dependent effect in the transverse emittances of momentum-analyzed {sup 28}Si{sup {minus}}, {sup 58}Ni{sup {minus}}, and {sup 197}Au{sup {minus}} negative-ion beams generated by cesium-ion sputtering. The differences in the emittances are found to be principally correlated with differences in the energy spreads in the respective ion beams, which have their origins in the sputter-ejection negative-ion formation process. The experimental equipment and techniques utilized for emittance data acquisition and analysis, and evidence for a species-dependent effect in the emittances and brightnesses of the subject ion beams, are presented in this paper.

1990-02-01

156

Environmental Impact Analysis Using Hybrid Decision Support Framework: A Transportation Project Case Study  

British Library Electronic Table of Contents (United Kingdom)

An Environmental Impact Assessment (EIA) study for any project is a time- consuming process because it has a large number of dependent and independent variables that must be taken into account. Although EIAs are dependent on geo-spatial information in order to make an assessment, there are no standard rules for conducting an environmental assessment. In addition, each assessment objective is case-dependent, based on what information is available. This paper presents a new framework for the analysis phase of the Environmental Impact Assessment (EIA) for projects, based on the integration between remote sensing technology, geographic information systems, and spatial modeling. The framework comprehensively analyzes the environmental vulnerability around the project areas and its impact on the...

2010-01-01

157

Effect of indirect dependencies on "A mutual information minimization approach for a class of nonlinear recurrent separating systems"  

CERN Document Server

In a recent paper [4], Duarte and Jutten investigated the Blind Source Separation (BSS) problem, for the nonlinear mixing model that they introduced in that paper. They proposed to solve this problem by using information-theoretic tools, more precisely by minimizing the mutual information (MI) of the outputs of the separating structure. When applying the MI approach to BSS problems, one usually determines the analytical expressions of the derivatives of the MI with respect to the parameters of the considered separating model. In the literature, these calculations were mainly reported for linear mixtures up to now. They are more complex for nonlinear mixtures, due to dependencies between the considered quantities. Moreover, the notations commonly employed by the BSS community in such calculations may become misleading when using them for nonlinear mixtures, due to the above-mentioned dependencies. We claim that the calculations reported in [4] ...

2009-01-01

158

Dynamic and static error analyses of neutron radiography testing  

Energy Technology Data Exchange (ETDEWEB)

Neutron radiography systems are being used for real-time visualization of the dynamic behavior as well as time-averaged measurements of spatial vapor fraction distributions for two phase fluids. The data in the form of video images are typically recorded on videotape at 30 frames per second. Image analysis of he video pictures is used to extract time-dependent or time-averaged data. The determination of the average vapor fraction requires averaging of the logarithm of time-dependent intensity measurements of the neutron beam (gray scale distribution of the image) that passes through the fluid. This could be significantly different than averaging the intensity of the transmitted beam and then taking the logarithm of that term. This difference is termed the dynamic error (error in the time-averaged vapor fractions due to the inherent time-dependence of the measured data) and is separate from the static error (statistical ...

1999-03-01

159

Depression of calcium pump activity in renal cortex of vitamin D-deficient rats with secondary hyperparathyroidism  

Energy Technology Data Exchange (ETDEWEB)

To examine the hormonal regulation of the ATP-dependent Ca{sup 2+} pump in the kidneys, the ATP-dependent Ca{sup 2+} uptake by the basolateral membrane vesicles in the renal cortex was measured using radioactive calcium ({sup 45}Ca{sup 2+}) in rats with vitamin D deficiency or rats undergoing thyroparathyroidectomy. The V{sub max} of the Ca{sup 2+} pump activity was increased not only by administering calcitriol, but also by normalizing the serum calcium level in vitamin D-deficient rats. PTH suppressed the Ca{sup 2+} pump activity in normocalcemic vitamin D-deficient rats. Thyroparathyroidectomy did not affect the Ca{sup 2+} pump activity in the kidneys of normal rats. It was concluded that the ATP-dependent Ca{sup 2+} pump activity was depressed by secondary hyperparathyroidism in vitamin D-deficient rats. (author).

1990-01-01

160

Depression of calcium pump activity in renal cortex of vitamin D-deficient rats with secondary hyperparathyroidism  

International Nuclear Information System (INIS)

To examine the hormonal regulation of the ATP-dependent Ca"2"+ pump in the kidneys, the ATP-dependent Ca"2"+ uptake by the basolateral membrane vesicles in the renal cortex was measured using radioactive calcium ("4"5Ca"2"+) in rats with vitamin D deficiency or rats undergoing thyroparathyroidectomy. The V_m_a_x of the Ca"2"+ pump activity was increased not only by administering calcitriol, but also by normalizing the serum calcium level in vitamin D-deficient rats. PTH suppressed the Ca"2"+ pump activity in normocalcemic vitamin D-deficient rats. Thyroparathyroidectomy did not affect the Ca"2"+ pump activity in the kidneys of normal rats. It was concluded that the ATP-dependent Ca"2"+ pump activity was depressed by secondary hyperparathyroidism in vitamin D-deficient rats. (author).

161

Dependence of impurity binding energy on nitrogen and indium concentrations for shallow donors in a GaInNAs/GaAs quantum well under intense laser field  

British Library Electronic Table of Contents (United Kingdom)

Within the framework of the effective-mass approximation, using a variational method, we have calculated the effect of intense laser radiation on the binding energy of the shallow-donor impurities in a Ga1- x In x N y As1- y /GaAs single quantum well for different nitrogen and indium mole concentrations. Our numerical results show that the binding energy strongly depends on the laser intensity and frequency (via the laser dressing parameter) and it also depends on the nitrogen and indium concentrations. Impurity binding energy under intense laser fields can be tuned by changing the nitrogen and indium mole fraction.

2011-01-01

162

Comparison between different procedures of reliability analysis for emergency and stand-by power systems  

Energy Technology Data Exchange (ETDEWEB)

A general purpose Emergency Generator Set (EGS) is considered for a methodological study and related reliability behavior is analyzed. In particular in a procedure of reliability and availability analysis of a EGS, dependent failure events need a complex mathematical model as state-space model to be a accurately evaluated. Furthermore these dependent failure events are one of the most important reliability characteristic of EGS. This paper suggests a procedure for reliability calculations in presence of dependent failure based on the evaluation of a equivalent failure rate that can be fitted to a network reduction method by simple mathematical calculations. The simplified models analyzed show a good accuracy for a wide range of variation of main reliability characteristics of EGS and utility. The advantages obtained are very useful on reliability evaluation because the possibility of use of network approach provides a ...

1995-12-31

163

Acceleration of particles in pulsar magnetosphere and the X-ray radiation  

CERN Document Server

The available data of single X-ray pulsars, their wind nebulae, and the SNRs which are connected to some of these sources are analysed. It is shown that electric field intensity of neutron stars tears off charged particles from the surface of neutron star and triggers the acceleration of particles. The charged particles are accelerated mainly in the field of magnetodipole radiation wave. Power and energy spectra of the charged particles depend on the strength of the magnetodipole radiation. Therefore, the X-ray radiation is strongly dependent on the rate of rotational energy loss and weakly dependent on the electric field intensity. Coulomb interaction between the charged particles is the main factor for the energy loss and the X-ray spectra of the charged particles.

2004-01-01

164

A new aspect of superconductivity in A-15 compounds  

International Nuclear Information System (INIS)

We present a new aspect of superconductivity in A-15 compounds which is able to explain their exceptional role among the high Tc superconductors. The basic idea is that a strong energy dependence of the the electronic density of states near the Fermi level may greatly reduce the repulsive part of the frequency dependent electron-phonon interaction. This leads to a large enhancement of Tc which is a maximum when the Fermi energy is comparable to a typical phonon energy. Our findings are based on numerical solutions of the Eliashberg equations where both the retardation of the electron-phonon coupling and the energy dependence of the electronic density of states have been included. For the electronic density of states we use the models of Labbe and Friedel and of Cohen et al., while the shape of the Eliashberg function #alpha#"2F(#omega#) is taken from the tunneling results of Shen. We compare our theory to experimental ...

165

3-D depth migration via McClellan transformations  

Energy Technology Data Exchange (ETDEWEB)

Three-dimensional seismic wavefields may be extrapolated in depth, one frequency at a time, by two-dimensional convolution with a circularly symmetric, frequency- and velocity-dependent filter. This depth extrapolation, performed for each frequency independently, lies at the heart of 3-D finite-difference depth migration. The computational efficiency of 3-D depth migration depends directly on the efficiency of this depth extrapolation. McClellan transformations provide an efficient method for both designing and implementing two-dimensional digital filters that have a particular form of symmetry, such as the circularly symmetric depth extrapolation filters used in 3-D depth migration. Given the coefficients of one-dimensional, frequency- and velocity-dependent filters used to accomplish 2-D depth migration, McClellan transformations lead to a simple and efficient algorithm for 3-D depth migration. 21 refs., 12 figs.

1990-01-01

166

Wnt3a Induces Myofibroblast Differentiation by Upregulating TGF-? Signaling Through SMAD2 in a ?-Catenin-Dependent Manner  

UK PubMed Central (United Kingdom)

Growing evidence suggests the Wnt family of secreted glycoproteins and their associated signaling pathways, linked to development, are recapitulated during wound repair and regeneration events. However,...Full Text Available

167

Understanding the nature of the statistics behind energy-related CO{sub 2} emissions  

Energy Technology Data Exchange (ETDEWEB)

Research reported here reveals that the reduction of CO{sub 2} emissions into the atmosphere, is mainly dependent on the decrease of the use of fossil fuels, but also on the development of environment-friendly technology and greening of the environment. 2 refs.

2001-07-01

168

Ubiquitin-Dependent Degradation of p53 Protein despite Phosphorylation at its N-Terminus by Acetaminophen  

UK PubMed Central (United Kingdom)

We previously reported that acetaminophen (APAP) caused apoptosis of C6 glioma cells. Therefore, we hypothesized that the level of p53, which usually stimulates apoptosis, might be increased...Full Text Available

2006-04-01

169

Tuberous Sclerosis Complex Activity is Required to Control Neuronal Stress Responses in an mTOR-Dependent Manner  

UK PubMed Central (United Kingdom)

Tuberous Sclerosis Complex (TSC) is a neurogenetic disorder caused by loss-of-function mutations in either the TSC1 or TSC2 genes and frequently results in...Full Text Available

2009-05-06

170

Trigeminal injury causes kappa opioid-dependent allodynic, glial and immune cell responses in mice  

UK PubMed Central (United Kingdom)

BackgroundThe dynorphin-kappa opioid receptor (KOR) system regulates glial proliferation after sciatic nerve injury. Here, we investigated its role in cell proliferation following...Full Text Available

171

Translation Elongation Factor 1A Facilitates the Assembly of the Tombusvirus Replicase and Stimulates Minus-Strand Synthesis  

UK PubMed Central (United Kingdom)

Replication of plus-strand RNA viruses depends on host factors that are recruited into viral replicase complexes. Previous studies showed that eukaryotic translation elongation factor (eEF1A) is one...Full Text Available

2010-11-01

172

Tone-Specific and Nonspecific Plasticity of the Auditory Cortex Elicited by Pseudoconditioning: Role of Acetylcholine Receptors and the Somatosensory Cortex  

UK PubMed Central (United Kingdom)

Experience-dependent plastic changes in the central sensory systems are due to activation of both the sensory and neuromodulatory systems. Nonspecific changes of cortical auditory neurons elicited by...Full Text Available

2008-09-01

173

Time-Dependent Expression of Arc and Zif268 after Acquisition of Fear Conditioning  

UK PubMed Central (United Kingdom)

Memory consolidation requires transcription and translation of new protein. Arc, an effector immediate early gene, and zif268, a regulatory transcription factor, have been implicated in synaptic plasticity...Full Text Available

2010-01-01

174

Time-Dependent Changes in Positively Biased Self-Perceptions of Children with ADHD: A Developmental Psychopathology Perspective  

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

2010-05-01

175

Thermal stability and acid resistance of aluminosilicophosphate zeolites  

Energy Technology Data Exchange (ETDEWEB)

By isomorphous replacement of silicon by phosphorus the authors have synthesized crystalline aluminosilicophosphates with structures of the zeolites type A and faujasite. They determine the adsorption capacity of specimens treated at 575-1275/sup 0/K. They show that the thermal stability and acid resistance of aluminosilicophosphates depend on the quantity of phosphorus in their structure.

1987-04-01

176

Thermal dislocation depinning in a deformed crystal  

Energy Technology Data Exchange (ETDEWEB)

The temperature dependence of the dislocation mobility threshold is investigated on the basis of a dislocation model suggested by Frenkel-Kontorova. The critical value is obtained for the stress/temperature, corresponding to the dislocation depinning from its equilibrium position. The universal behaviour of a barrier height at finite stress and temperature is revealed and investigated.

2008-01-14

177

The risk of establishment of aquatic invasive species: joining invasibility and propagule pressure  

UK PubMed Central (United Kingdom)

Invasive species are increasingly becoming a policy priority. This has spurred researchers and managers to try to estimate the risk of invasion. Conceptually, invasions are dependent both on the receiving...Full Text Available

2007-10-22

178

The interplay of StyR and IHF regulates substrate-dependent induction and carbon catabolite repression of styrene catabolism genes in Pseudomonas fluorescens ST  

UK PubMed Central (United Kingdom)

BackgroundIn Pseudomonas fluorescens ST, the promoter of the styrene catabolic operon, PstyA, is induced by styrene and is subject to catabolite...Full Text Available

179

The inhibition of tumor cell intravasation and subsequent metastasis through the regulation of in vivo tumor cell motility by the tetraspanin CD151  

UK PubMed Central (United Kingdom)

SummaryIn vivo tumor cell migration through integrin-dependent pathways is key to the metastatic behavior of malignant cells. Using quantitative in vivo...Full Text Available

2008-03-01

180

The influence of the explosion of the conductor of an electric cable on the dielectric properties of the polymer insulator  

British Library Electronic Table of Contents (United Kingdom)

The electric explosion of a conductor being part of an electric cable is studied. It is ascertained that the electric properties of a polymeric dielectric depend nonlinearly on the maintenance of the ultradisperse metal filler. In the course of the numerous heating-cooling processes of an insulator, a streamlining of the structure of a polymeric composite occurs.

2010-01-01

181

The influence of metallurgical variables on the temperature dependence of irradiation hardening in pressure vessel steels  

International Nuclear Information System (INIS)

Yield stress elevations (#DELTA##sigma#_y) in pressure vessel steels irradiated at intermediate flux and fluence systematically decreased with increasing temperature and decreasing copper and nickel content. Lower stress relief temperature also decreased #DELTA##sigma#_y at bulk copper concentrations greater than about 0.3%. The dependence of #DELTA##sigma#_y on irradiation temperature between 260 and 316 C increased with copper and nickel content and decreased with phosphorus content. When normalized by the average #DELTA##sigma#_y, the fractional temperature dependence correlates with a simple empirical chemistry factor of copper and phosphorus. The correlation predicts data on the irradiation temperature dependence of #DELTA##sigma#_y found in the literature within a standard error of about 0.3 MPa/degree C and is consistent with current understanding of hardening mechanisms. However, questions remain about the effects ...

1994-06-20

182

The efflux of a fluorescent probe is catalyzed by an ATP-driven extrusion system in Lactococcus lactis.  

UK PubMed Central (United Kingdom)

Many bacteria, both gram positive and gram negative, extrude in an energy-dependent manner the fluorescent pH indicator 2',7'-bis-(2-carboxyethyl)-5[and -6]-carboxyfluorescein (BCECF) (D. Molenaar,...Full Text Available

1992-05-01

183

The concept of mental disorder: diagnostic implications of the harmful dysfunction analysis  

UK PubMed Central (United Kingdom)

What do we mean when we say that a mental condition is a medical disorder rather than a normal form of human suffering or a problem in living? The status of psychiatry as a medical discipline depends...Full Text Available

2007-10-01

184

The Induction of APC with a Distinct Tolerogenic Phenotype via Contact-Dependent STAT3 Activation  

UK PubMed Central (United Kingdom)

BackgroundActivation of the signal transducer and activator of transcription 3 (STAT3) within antigen presenting cells (APCs) is linked to abnormal APCs differentiation and function....Full Text Available

185

Temperature dependence of a twofold magnetic behaviour of a nanoscopic metal/silicon hybrid system - a comparison between Ni/Si and Co/Si  

Energy Technology Data Exchange (ETDEWEB)

The investigated hybrid nanocomposite consists of a porous silicon template with electrochemically embedded Ni or Co nanostructures and offers magnetic characteristics which can be tailored by the electrochemical process parameters during fabrication. A twofold magnetic behaviour can be observed, a first one due to the spinmagnetism at magnetic fields below the saturation magnetization of the deposited metals and a second non-saturating term at higher fields (>1 T up to 7 T) above the saturation magnetization. In case of Ni deposited within the pores this non-saturating term shows a paramagnetic characteristic and follows exactly the Curie-Weiss law, whereas for Co/porous silicon samples the temperature dependent magnetization shows some deviations from the Curie Weiss law. In this high field region a difference in the temperature dependence between Ni and Co is observed whereas the non-saturating term does not ...

2009-10-15

186

Suppression by IgA of IgG-mediated phagocytosis by human polymorphonuclear leucocytes  

UK PubMed Central (United Kingdom)

IgA from normal human serum, a myeloma IgA and human colostral IgA were found to inhibit the IgG-dependent phagocytosis of Candida albicans (CA) blastospores by polymorphonuclear leucocytes...Full Text Available

1978-12-01

187

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

UK PubMed Central (United Kingdom)

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

2009-09-01

188

Stretched DNA Investigated Using Molecular-Dynamics and Quantum-Mechanical Calculations  

UK PubMed Central (United Kingdom)

AbstractWe combined atomistic molecular-dynamics simulations with quantum-mechanical calculations to investigate the sequence dependence of the stretching behavior of duplex DNA. Our...Full Text Available

2010-01-06

189

Standardization of clinical decision making for the conduct of credible clinical research in complicated medical environments.  

UK PubMed Central (United Kingdom)

The likelihood that past experience will produce correct guides to current practice depends on the signal-to-noise ratio for the clinical problem of interest. If the signal-to-noise ratio is high, the...Full Text Available

1996-01-01

190

Spatial Re-Establishment Dynamics of Local Populations of Vectors of Chagas Disease  

UK PubMed Central (United Kingdom)

BackgroundPrevention of Chagas disease depends mainly on control of the insect vectors that transmit infection. Unfortunately, the vectors have been resurgent in some areas. It is...Full Text Available

191

Sodium ion-dependent amino acid transport in membrane vesicles of Bacillus stearothermophilus.  

UK PubMed Central (United Kingdom)

Amino acid transport in membrane vesicles of Bacillus stearothermophilus was studied. A relatively high concentration of sodium ions is needed for uptake of L-alanine (Kt = 1.0 mM) and L-leucine (Kt...Full Text Available

1991-01-01

192

Smoking and Illicit Drug Use Associations With Early Versus Delayed Reproduction: Findings in a Young Adult Cohort of Australian Twins*  

UK PubMed Central (United Kingdom)

Objective:This article examines relationships between reproductive onset and lifetime history of smoking, regular smoking, and nicotine dependence, and cannabis and other illicit...Full Text Available

2009-09-01

193

Severe teratozoospermia and its influence on pronuclear morphology, embryonic cleavage and compaction  

UK PubMed Central (United Kingdom)

BackgroundFertilization, cell division and embryo development depend on genomic contributions from male and female gametes. We hypothesize that teratozoospermic sperm influences...Full Text Available

194

Serotype- and strain- dependent contribution of the sensor kinase CovS of the CovRS two-component system to Streptococcus pyogenes pathogenesis  

UK PubMed Central (United Kingdom)

BackgroundThe Streptococcus pyogenes (group A streptococci, GAS) two-component signal transduction system CovRS has been described to be important for pathogenesis...Full Text Available

195

Sensitivity limits for voltage control of P2Y receptor-evoked Ca2+ mobilization in the rat megakaryocyte  

UK PubMed Central (United Kingdom)

G-protein-coupled receptor signalling has been suggested to be voltage dependent in a number of cell types; however, the limits of sensitivity of this potentially important phenomenon are unknown. Using...Full Text Available

2004-02-15

196

Semileptonic b to u transition  

CERN Document Server

Experimental studies of charmless semileptonic B decays can be broadly categorized into inclusive and exclusive measurements depending on how the final states are treated. The inclusive method measures the decay rate $\\Gamma(B \\to X_u \\ell \

2007-01-01

197

Scheme for Entangling Two Distant Cavity Mirrors  

International Nuclear Information System (INIS)

A scheme is presented for the generation of entangled states for two cavity mirrors. In the scheme each mirror initially in a vacuum state interacts with a weak coherent field, resulting in a photon-number dependent kick. The detection of a photon leaking from the cavities collapses the two mirrors to an entangled state.

2008-04-15

198

Role of Calcium in Serine Transport into Tobacco Cells  

UK PubMed Central (United Kingdom)

The transport of serine into tobacco (Nicotiana tabacum L. var. Xanthi) cells grown in liquid medium was studied. Serine transport was maximal below pH 4.0. A time-dependent stimulation...Full Text Available

1978-12-01

199

Role of Bv8 in neutrophil-dependent angiogenesis in a transgenic model of cancer progression  

UK PubMed Central (United Kingdom)

The secreted Bv8 protein has been recently characterized as a regulator of myeloid cell mobilization and a neutrophil-derived mediator of tumor angiogenesis in several xenografts, but its role in tumor...Full Text Available

2008-02-19

200

Rhythmic expression of an egr-1 transgene in rats distinguishes two populations of photoreceptor cells in the retinal outer nuclear layer  

UK PubMed Central (United Kingdom)

PurposeNocturnal rhythms of gene expression in the retina are known to be both darkness- and circadian clock-dependent, but their role and cellular location are not well defined....Full Text Available

201

Research and development of a new RF-assisted device for bloodless rapid transection of the liver: Computational modeling and in vivo experiments  

UK PubMed Central (United Kingdom)

BackgroundEfficient and safe transection of biological tissue in liver surgery is strongly dependent on the ability to address both parenchymal division and hemostasis simultaneously....Full Text Available

202

Relationship between petal abscission and programmed cell death in Prunus yedoensis and Delphinium belladonna  

UK PubMed Central (United Kingdom)

Depending on the species, the end of flower life span is characterized by petal wilting or by abscission of petals that are still fully turgid. Wilting at the end of petal life is due to programmed...Full Text Available

2007-10-01

203

Regulation of G1 Cell Cycle Progression  

UK PubMed Central (United Kingdom)

Most genetic changes that promote tumorigenesis involve dysregulation of G1 cell cycle progression. A key regulatory site in G1 is a growth factor–dependent restriction point (R) where cells...Full Text Available

2010-11-01

204

Range and modulation dependencies for proton beam dose per monitor unit calculations  

UK PubMed Central (United Kingdom)

Calculations of dose per monitor unit (D∕MU) are required in addition to measurements to increase patient safety in the clinical practice of proton radiotherapy. As in conventional photon and...Full Text Available

2009-02-01

205

Range accuracy in carbon ion treatment planning based on CT-calibration with real tissue samples  

UK PubMed Central (United Kingdom)

BackgroundThe precision in carbon ion radiotherapy depends on the calibration of Hounsfield units (HU) as measured with computed tomography (CT) to water equivalence. This calibration...Full Text Available

206

RXR activators molecular signalling: involvement of a PPAR?-dependent pathway in the liver and kidney, evidence for an alternative pathway in the heart  

UK PubMed Central (United Kingdom)

In this study we compared the molecular signalling elicited by rexinoids, selective retinoid X receptor (RXR)-activators, in several organs (i.e. liver, kidney,...Full Text Available

2003-03-01

207

RESPONSE LATENCY AS AN INDEX OF RESPONSE STRENGTH DURING FUNCTIONAL ANALYSES OF PROBLEM BEHAVIOR  

UK PubMed Central (United Kingdom)

Dependent variables in research on problem behavior typically are based on measures of response repetition, but these measures may be problematic when behavior poses high risk or when its occurrence...Full Text Available

2011-01-01

208

Quantitative bone scintigraphy in children and adolescents. Age dependence of skeleton uptake  

International Nuclear Information System (INIS)

French ... Orig. Title Scintigraphie osseuse quantifiee chez l'enfant et l'adolescent - repartition selon l'age des taux de fixation de diverses pieces osseuses normales.

209

QTL analysis of measures of mouse home-cage activity using B6/MSM consomic strains  

UK PubMed Central (United Kingdom)

The activity of mice in their home cage is influenced greatly by the cycle of light and dark. In addition, home-cage activity shows remarkable time-dependent changes that result in a prominent temporal...Full Text Available

2010-10-01

210

Pseudomonas aeruginosa selective adherence to and entry into human endothelial cells.  

UK PubMed Central (United Kingdom)

The pathogenesis of Pseudomonas aeruginosa disseminated infections depends on bacterial interaction with blood vessels. We have hypothesized that in order to traverse the endothelial barrier, bacteria...Full Text Available

1994-12-01

211

Protein Targets of Reactive Metabolites of Thiobenzamide in Rat Liver In Vivo  

UK PubMed Central (United Kingdom)

Thiobenzamide (TB) is a potent hepatotoxin in rats, causing dose-dependent hyperbilirubinemia, steatosis, and centrolobular necrosis. These effects arise subsequent to and appear to result from...Full Text Available

2008-07-01

212

Practical screening of purified cellobiohydrolases and endoglucanases with ?-cellulose and specification of hydrodynamics  

UK PubMed Central (United Kingdom)

BackgroundIt is important to generate biofuels and society must be weaned from its dependency on fossil fuels. In order to produce biofuels, lignocellulose is pretreated and the...Full Text Available

213

Phytoestrogens: epidemiology and a possible role in cancer protection.  

UK PubMed Central (United Kingdom)

Because many diseases of the Western Hemisphere are hormone-dependent cancers, we have postulated that the Western diet, compared to a vegetarian or semivegetarian diet, may alter hormone production,...Full Text Available

1995-10-01

214

Physical Basis for the Lg/P Discriminant: General Properties and Preliminary Modeling.  

Science.gov (United States)

A critical problem for reliable implementation of regional discrimination is incomplete understanding of how regional seismic signals depend on physical characteristics of the source and propagation path to the recording station. This research is directed...

1997-01-01

215

Phosphorylation-dependent power output of transgenic flies: an integrated study.  

UK PubMed Central (United Kingdom)

We examine how the structure and function of indirect flight muscle (IFM) and the entire flight system of Drosophila melanogaster are affected by phosphorylation of the myosin regulatory light chain...Full Text Available

1997-12-01

216

Phonetic recalibration does not depend on working memory  

UK PubMed Central (United Kingdom)

Listeners use lipread information to adjust the phonetic boundary between two speech categories (phonetic recalibration, Bertelson et al. 2003). Here, we examined...Full Text Available

2010-06-01

217

Perceptual training narrows the temporal window of multisensory binding  

UK PubMed Central (United Kingdom)

The brain’s ability to bind incoming auditory and visual stimuli depends critically on the temporal structure of this information. Specifically, there exists a temporal window of audiovisual...Full Text Available

2009-09-30

218

Pathogenic Role of NKT and NK Cells in Acetaminophen-Induced Liver Injury is Dependent on the Presence of DMSO  

UK PubMed Central (United Kingdom)

Dimethyl sulfoxide (DMSO) is commonly used in biological studies to dissolve drugs and enzyme inhibitors with low solubility. While DMSO is generally thought of as being relatively inert, it...Full Text Available

2008-09-01

219

Patency rate and complications of polytetrafluoroethylene grafts compared with polyurethane grafts for hemodialysis access  

UK PubMed Central (United Kingdom)

BackgroundThe survival of hemodialysis patients requiring dialysis depends on the long-term functioning and patency of the vascular access. Prosthetic vascular grafts are inevitably...Full Text Available

2010-10-01

220

P2X purinoceptors mediate an endothelium-dependent hyperpolarization in longitudinal smooth muscle of anterior mesenteric artery in young chickens  

UK PubMed Central (United Kingdom)

Background and purpose:The chicken anterior mesenteric artery contains an outer longitudinal smooth muscle layer, whose neural regulation remains to be elucidated. ATP evokes a depolarization...Full Text Available

2009-10-01

221

Oxygen-dependent catabolism of indole-3-acetic acid in Bradyrhizobium japonicum.  

UK PubMed Central (United Kingdom)

Some strains of Bradyrhizobium japonicum have the ability to catabolize indole-3-acetic acid (IAA). Examination of this catabolism in strain 110 by in vivo experiments has revealed an enzymatic activity...Full Text Available

1991-08-01

222

Oxalate- and Glyoxylate-Dependent Growth and Acetogenesis by Clostridium thermoaceticum  

UK PubMed Central (United Kingdom)

The acetogenic bacterium Clostridium thermoaceticum ATCC 39073 grew at the expense of the two-carbon substrates oxalate and glyoxylate. Other two-carbon substrates (acetaldehyde, acetate,...Full Text Available

1993-09-01

223

Outcomes Associated with Race in Males with Nondialysis-Dependent Chronic Kidney Disease  

UK PubMed Central (United Kingdom)

Background and objectives: Blacks are over-represented among dialysis patients, but they have better survival rates than whites. It is unclear if the over-representation of blacks on dialysis is due...Full Text Available

2009-05-01

224

On the dependence of some helium shell flash characteristics on core mass  

Energy Technology Data Exchange (ETDEWEB)

A theoretical derivation of the intershell mass--core mass relation of Paczynski is attempted. Formulae developed by Sugimoto and Fujimoto are extended to less massive (m/sub c/< or approx. =1) cores.

1980-08-15

225

Oligodendrocyte-Myelin Glycoprotein and Nogo Negatively Regulate Activity-Dependent Synaptic Plasticity  

UK PubMed Central (United Kingdom)

In the adult mammalian CNS, the growth inhibitors oligodendrocyte-myelin glycoprotein (OMgp) and the reticulon RTN4 (Nogo) are broadly expressed in oligodendrocytes and neurons. Nogo and OMgp...Full Text Available

2010-09-15

226

O2-dependent methionine auxotrophy in Cu,Zn superoxide dismutase-deficient mutants of Saccharomyces cerevisiae.  

UK PubMed Central (United Kingdom)

Mutant strains of the yeast Saccharomyces cerevisiae which lack functional Cu,Zn superoxide dismutase (SOD-1) do not grow aerobically unless supplemented with methionine. The molecular basis of this...Full Text Available

1990-04-01

227

Nucleoside Drugs Induce Cellular Differentiation by Caspase-Dependent Degradation of Stem Cell Factors  

UK PubMed Central (United Kingdom)

BackgroundStem cell characteristics are an important feature of human cancer cells and play a major role in the therapy resistance of tumours. Strategies to target cancer stem cells...Full Text Available

228

Nitrogen Fixation, Nodule Development, and Vegetative Regrowth of Alfalfa (Medicago sativa L.) following Harvest 1  

UK PubMed Central (United Kingdom)

Nitrogenase-dependent acetylene reduction, nodule function, and nodule regrowth were studied during vegetative regrowth of harvested (detopped) alfalfa (Medicago sativa L.) seedlings...Full Text Available

1979-07-01

229

Naturally occurring double-stranded RNA and immune responses. Effects on plaque-forming cells and antibody formation.  

UK PubMed Central (United Kingdom)

A highly purified preparation of double-stranded RNA, obtained from virus-like particles in Penicillium cultures, was found to affert humoral immune responses in mice differentially depending on its...Full Text Available

1975-03-01

230

Nasal retention of budesonide and fluticasone in man: Formation of airway mucosal budesonide-esters in vivo  

UK PubMed Central (United Kingdom)

AimsThe efficacy of topical glucocorticosteroids in rhinitis and asthma is likely to depend on drug retention in the airway mucosa. With fluticasone propionate, retention may be...Full Text Available

2001-02-01

231

Muscle-Specific Calpain is Localized in Regions Near Motor Endplates in Differentiating Lobster Claw Muscles  

UK PubMed Central (United Kingdom)

Calpains are Ca2+-dependent proteinases that mediate protein turnover in crustacean skeletal muscles. We used an antibody directed against lobster muscle-specific calpain (Ha-CalpM)...Full Text Available

2007-11-01

232

Monte Carlo modeling of 60Co HDR brachytherapy source in water and in different solid water phantom materials  

UK PubMed Central (United Kingdom)

The reference medium for brachytherapy dose measurements is water. Accuracy of dose measurements of brachytherapy sources is critically dependent on precise measurement of the source–detector...Full Text Available

2010-01-01

233

Molecular dynamics of a ?B DNA element: base flipping via cross-strand intercalative stacking in a microsecond-scale simulation  

UK PubMed Central (United Kingdom)

The sequence-dependent structural variability and conformational dynamics of DNA play pivotal roles in many biological milieus, such as in the site-specific binding of transcription factors to target...Full Text Available

2008-09-01

234

Modulation of B-cell endoplasmic reticulum calcium homeostasis by Epstein-Barr virus Latent Membrane Protein-1  

UK PubMed Central (United Kingdom)

BackgroundCalcium signaling plays an important role in B lymphocyte survival and activation, and is critically dependent on the inositol-1,4,5-tris-phosphate-induced...Full Text Available

235

Microsoft Word - ~4679716.doc  

Wastenet

UNEP will provide in the first CPR quarterly report of 2011 the financial statements for 2010. ...for assessing and rating programme performance UNEP to work with the CPR to identify better ways of streamlining reporting requirements ...in 2011 to achieve the ratios requested by the CPR dependent on receipt of contributions originally planned for the

236

Mechanisms of confluence-dependent expression of CD26 in colon cancer cell lines  

UK PubMed Central (United Kingdom)

BackgroundCD26 (dipeptidyl peptidase IV, DPPIV) is a 110 kDa surface glycoprotein expressed in most normal tissues, and is a potential novel therapeutic target for selected cancers....Full Text Available

237

Maturation of GABAergic Inhibition Promotes Strengthening of Temporally Coherent Inputs among Convergent Pathways  

UK PubMed Central (United Kingdom)

Spike-timing-dependent plasticity (STDP), a form of Hebbian plasticity, is inherently stabilizing. Whether and how GABAergic inhibition influences STDP is not well understood. Using a model neuron driven...Full Text Available

2010-06-01

238

Maternal effects and range expansion: a key factor in a dynamic process?  

UK PubMed Central (United Kingdom)

Species that depend on ephemeral habitat often evolve distinct dispersal strategies in which the propensity to disperse is closely integrated with a suite of morphological, behavioural and physiological...Full Text Available

2009-04-27

239

Mammalian Sirtuins and Energy Metabolism  

UK PubMed Central (United Kingdom)

Sirtuins are highly conserved NAD+-dependent protein deacetylases and/or ADP-ribosyltransferases that can extend the lifespan of several lower model organisms including yeast, worms and flies....Full Text Available

240

Mammalian Sirt1: insights on its biological functions  

UK PubMed Central (United Kingdom)

Sirt1 (member of the sirtuin family) is a nicotinamide adenosine dinucleotide (NAD)-dependent deacetylase that removes acetyl groups from various proteins. Sirt1 performs a wide variety of functions...Full Text Available

241

Malate- and Pyruvate-Dependent Fatty Acid Synthesis in Leucoplasts from Developing Castor Endosperm 1  

UK PubMed Central (United Kingdom)

Leucoplasts were isolated from the endosperm of developing castor (Ricinis communis) endosperm using a discontinuous Percoll gradient. The rate of fatty acid synthesis was highest...Full Text Available

1992-04-01

242

Long-Lasting Adaptations of the NR2B-containing NMDA Receptors in the Dorsomedial Striatum Play a Crucial Role in Alcohol Consumption and Relapse  

UK PubMed Central (United Kingdom)

A growing number of studies suggest that the development of compulsive drug seeking and taking depends on dorsostriatal mechanisms. We previously observed that ex vivo acute...Full Text Available

2010-07-28

243

Lockheed WP-3D Orion  

Science.gov (United States)

Approximately 62,000 lbs Fuel Load: 58,000 lbs. Type Fuel: JP4, JP5, JP8, JET A, JET A-1, JET B Standard Fuel Burn: 4500 - 6000 lbs/hr depending on altitude and airspeed Maximum...

2011-08-17

244

Light-Dependent Regulation of Cyanobacterial Phytochrome Expression  

UK PubMed Central (United Kingdom)

A histidine kinase protein (Cph1) with sequence homology and spectral characteristics very similar to those of the plant phytochrome has been recently identified in the cyanobacterium Synechocystis...Full Text Available

2000-01-01

245

Life Span Extension in Mice by Food Restriction Depends on an Energy Imbalance12  

UK PubMed Central (United Kingdom)

In this study, our main objective was to determine whether energy restriction (ER) affects the rate of oxygen consumption of mice transiently or lastingly and whether metabolic rate plays a role in...Full Text Available

2009-03-01

246

Leptin receptor gene expression and number in the brain are regulated by leptin level and nutritional status  

UK PubMed Central (United Kingdom)

Hormone potency depends on receptor availability, regulated via gene expression and receptor trafficking. To ascertain how central leptin receptors are regulated, the effects of leptin challenge, high-fat...Full Text Available

2009-07-15

247

Lack of Association Between Prokineticin 2 Gene and Japanese Methamphetamine Dependence  

UK PubMed Central (United Kingdom)

Disruption of circadian rhythms may be involved in the pathophysiology of psychiatric disorders, including drug addiction. Recently, we detected the significant association between prokineticin 2 receptor...Full Text Available

2011-03-01

248

Is the operative delivery rate in low-risk women dependent on the level of birth care? A randomised controlled trial  

UK PubMed Central (United Kingdom)

ObjectiveTo investigate possible differences in operative delivery rate among low-risk women, randomised to an alongside midwifery-led unit or to standard obstetric units within...Full Text Available

2011-10-01

249

Interictal Functional Connectivity of Human Epileptic Networks Assessed by Intracerebral EEG and BOLD Signal Fluctuations  

UK PubMed Central (United Kingdom)

In this study, we aimed to demonstrate whether spontaneous fluctuations in the blood oxygen level dependent (BOLD) signal derived from resting state functional magnetic resonance imaging (fMRI) reflect...Full Text Available

250

Insights into Cdc13 dependent telomere length regulation  

UK PubMed Central (United Kingdom)

Cdc13 is a single stranded telomere binding protein that specifically localizes to the telomere ends of budding yeasts and is essential for cell viability. It caps the ends of chromosomes thus preventing...Full Text Available

251

Influence of the interstimulus interval on temporal processing and learning: testing the state-dependent network model  

UK PubMed Central (United Kingdom)

The ability to determine the interval and duration of sensory events is fundamental to most forms of sensory processing, including speech and music perception. Recent experimental data support the notion...Full Text Available

2009-07-12

252

Indole-3-Acetic Acid Biosynthesis in Colletotrichum gloeosporioides f. sp. aeschynomene  

UK PubMed Central (United Kingdom)

We characterized the biosynthesis of indole-3-acetic acid by the mycoherbicide Colletotrichum gloeosporioides f. sp. aeschynomene. Auxin production was tryptophan dependent....Full Text Available

1998-12-01

253

Increased rigidity of the chiral centre of tocainide favours stereoselectivity and use-dependent block of skeletal muscle Na+ channels enhancing the antimyotonic activity in vivo  

UK PubMed Central (United Kingdom)

Searching for the structural requirements improving the potency and the stereoselectivity of Na+ channel blockers as antimyotonic agents, new...Full Text Available

2001-12-01

254

Incorporating a Language/Action Design Perspective into a Computer-Based Psychiatric Alerting System  

UK PubMed Central (United Kingdom)

User acceptance of a computer system depends on a number of factors, including broad social and professional concerns regarding the system's impact on the work environment. This observation is especially...Full Text Available

1989-11-08

255

Inactivating cholecystokinin-2 receptor inhibits progastrin-dependent colonic crypt fission, proliferation, and colorectal cancer in mice  

UK PubMed Central (United Kingdom)

Hyperproliferation of the colonic epithelium, leading to expansion of colonic crypt progenitors, is a recognized risk factor for colorectal cancer. Overexpression of progastrin, a nonamidated and incompletely...Full Text Available

2009-09-01

256

Identification of plasmid and Bacillus subtilis chromosomal recombination sites used for pE194 integration.  

UK PubMed Central (United Kingdom)

The plasmid pE194 (3.7 kilobases) is capable of integrating into the genome of the bacterial host Bacillus subtilis in the absence of the major homology-dependent RecE recombination system. Multiple...Full Text Available

1989-05-01

257

Identification of circulating neuropilin-1 and dose-dependent elevation following anti-neuropilin-1 antibody administration  

UK PubMed Central (United Kingdom)

Neuropilin-1 (NRP1) acts as a co-receptor for class 3 semaphorins and vascular endothelial growth factor and is an attractive angiogenesis target for cancer therapy. In addition to the transmembrane...Full Text Available

2009-07-01

258

Ia-antigen-T-cell interactions for a thymus-independent antigen composed of D amino acids.  

UK PubMed Central (United Kingdom)

Synthetic polypeptide antigens of L amino acids, although bearing repeating sequences, are thymus-dependent (L-TD), whereas the same polymers composed of D amino acids are thymus-independent (D-TI),...Full Text Available

1993-02-01

259

IL-6-Dependent Mucosal Protection Prevents Establishment of a Microbial Niche for Attaching/Effacing Lesion-Forming Enteric Bacterial Pathogens1  

UK PubMed Central (United Kingdom)

Enteric infections with attaching/effacing lesion-inducing bacterial pathogens are a worldwide health problem. A murine infection model with one such pathogen, Citrobacter rodentium,...Full Text Available

2008-05-15

260

Hysteretic Behavior of Proprotein Convertase 1/3 (PC1/3)  

UK PubMed Central (United Kingdom)

The proprotein convertases (PCs) are calcium-dependent proteases responsible for processing precursor proteins into their active forms in eukariotes. The PC1/3 is a pivotal enzyme of this family that...Full Text Available

261

Hydrogen in metals  

International Nuclear Information System (INIS)

An important application of metal hydrides is as a moderator material in nuclear reactors. The fundamental properties of hydrides are illustrated and an impression given of the current research into hydrogen in transition metals. Phase diagrams, magnetic properties, temperature dependence of the diffusion coefficient, energy level schemes and superconductivity are considered. (C.F.).

262

How DNA coiling enhances target localization by proteins  

UK PubMed Central (United Kingdom)

Many genetic processes depend on proteins interacting with specific sequences on DNA. Despite the large excess of nonspecific DNA in the cell, proteins can locate their targets rapidly. After initial...Full Text Available

2008-10-14

263

Highly Conserved Regimes of Neighbor-Base-Dependent Mutation Generated the Background Primary-Structural Heterogeneities along Vertebrate Chromosomes  

UK PubMed Central (United Kingdom)

The content of guanine+cytosine varies markedly along the chromosomes of homeotherms and great effort has been devoted to studying this heterogeneity and its biological implications. Already...Full Text Available

264

Heat Stress Enhances the Accumulation of Polyadenylated Mitochondrial Transcripts in Arabidopsis thaliana  

UK PubMed Central (United Kingdom)

BackgroundPolyadenylation of RNA has a decisive influence on RNA stability. Depending on the organisms or subcellular compartment, it either enhances transcript stability or targets...Full Text Available

265

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

UK PubMed Central (United Kingdom)

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

2010-12-10

266

Growth-Phase-Dependent Expression of Virulence Factors in an M1T1 Clinical Isolate of Streptococcus pyogenes  

UK PubMed Central (United Kingdom)

The effect of growth phase on expression of virulence-associated factors was studied by Northern hybridization in an M1T1 clinical isolate of Streptococcus pyogenes. Expression of M...Full Text Available

1999-10-01

267

Gratitude and Well Being  

UK PubMed Central (United Kingdom)

The word “gratitude” has a number of different meanings, depending on the context. However, a practical clinical definition is as follows—gratitude is the appreciation...Full Text Available

268

Glomerular filtration and tubular reabsorption of albumin in preproteinuric and proteinuric diabetic rats.  

UK PubMed Central (United Kingdom)

Microalbuminuria (26-250 mg/d) is considered to be an indicator of incipient diabetic nephropathy in humans in insulin-dependent diabetes (IDD). However, before microalbuminuria is observed, glomerular...Full Text Available

1993-08-01

269

Germ cell sex determination in mammals  

UK PubMed Central (United Kingdom)

One of the major decisions that germ cells make during their development is whether to differentiate into oocytes or sperm. In mice, the germ cells’ decision to develop as male or female depends...Full Text Available

2009-04-01

270

Formate Dehydrogenase of Clostridium thermoaceticum: Incorporation of Selenium-75, and the Effects of Selenite, Molybdate, and Tungstate on the Enzyme  

UK PubMed Central (United Kingdom)

The formation of the nicotinamide adenine dinucleotide phosphate-dependent formate dehydrogenase in Clostridium thermoaceticum is stimulated by the presence of molybdate and selenite...Full Text Available

1973-11-01

271

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

UK PubMed Central (United Kingdom)

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

2006-05-09

272

Fluctuating feather asymmetry in relation to corticosterone levels is sex-dependent in Eurasian treecreeper (Certhia familiaris) nestlings  

UK PubMed Central (United Kingdom)

Fluctuating asymmetry (FA) has been widely used as a stress-related phenotypic marker of developmental instability. However, previous studies relating FA to various stressful conditions have produced...Full Text Available

2010-08-23

273

Fine Needle Aspiration Cytology of the Breast: The Nonmalignant Categories  

UK PubMed Central (United Kingdom)

Currently, accurate diagnosis of breast lesions depends on a triple assessment approach comprising clinical, imaging and pathologic examinations. Fine needle aspiration cytology (FNAC) is widely adopted...Full Text Available

274

Expression of the ?B-Dependent General Stress Regulon Confers Multiple Stress Resistance in Bacillus subtilis  

UK PubMed Central (United Kingdom)

The alternative sigma factor ςB of Bacillus subtilis is required for the induction of approximately 100 genes after the imposition of a whole range of stresses and...Full Text Available

1999-07-01

275

Experimental research of stability of thin films on the basis of depleted uranium as reflecting coating for wavelength of 4.5 nm  

International Nuclear Information System (INIS)

In this paper, we present experimentally determined reflection factors of mirrors based on the depleted uranium and dependence of reflection factor on time of presence of samples on air.

2007-05-21

276

Experimental X-ray intensity ratio L#beta#/L#alpha#  

International Nuclear Information System (INIS)

Experimental, relative intensities for the components of L X-ray were collected from literature, and atomic-number dependency of L#beta#/L#alpha# has been found. (author).

1980-01-01

277

Exercise alters SIRT1, SIRT6, NAD and NAMPT levels in skeletal muscle of aged rats  

UK PubMed Central (United Kingdom)

Silent information regulators are potent NAD+-dependent protein deacetylases, which have been shown to regulate gene silencing, muscle differentiation and DNA damage repair. Here,...Full Text Available

2010-01-01

278

Evidence for Iron-Dependent Nitrate Respiration in the Dissimilatory Iron-Reducing Bacterium Geobacter metallireducens  

UK PubMed Central (United Kingdom)

The dissimilatory iron-reducing bacterium Geobacter metallireducens was found to require iron at a concentration in excess of 50 μM for continuous cultivation on nitrate. Growth...Full Text Available

2001-08-01

279

Ethylene-Induced Leaf Abscission in Cotton Seedlings 1  

UK PubMed Central (United Kingdom)

The speed of ethylene-induced leaf abscission in cotton (Gossypium hirsutum L. cv LG-102) seedlings is dependent on leaf position (i.e. physiological age). Fumigation...Full Text Available

1991-01-01

280

Enterococcus faecalis Heme-Dependent Catalase  

UK PubMed Central (United Kingdom)

Enterococcus faecalis cells cannot synthesize porphyrins and do not rely on heme for growth but can take up heme and use it to synthesize heme proteins. We recently described a cytochrome...Full Text Available

2002-11-01

281

Engineering ligand-responsive RNA controllers in yeast through the assembly of RNase III tuning modules  

UK PubMed Central (United Kingdom)

The programming of cellular networks to achieve new biological functions depends on the development of genetic tools that link the presence of a molecular signal to gene-regulatory activity. Recently,...Full Text Available

2011-07-01

282

Ellman's-reagent-mediated regeneration of trypanothione in situ: substrate-economical microplate and time-dependent inhibition assays for trypanothione reductase.  

UK PubMed Central (United Kingdom)

Trypanothione reductase (TryR) is a key enzyme involved in the oxidative stress management of the Trypanosoma and Leishmania parasites, which helps to maintain an intracellular reducing environment...Full Text Available

2003-02-01

283

Electron Transport-Dependent Chlorophyll-a Fluorescence Quenching by O2 in Various Algae and Higher Plants  

UK PubMed Central (United Kingdom)

A comparison of chlorophyll-a fluorescence in brown algae (Macrocystis integrifolia, Fucus vesiculosis), green algae (Scenedesmus obliquus, Ulva sp.)...Full Text Available

1983-12-01

284

EGFR Signaling Through an Akt-SREBP-1-Dependent, Rapamycin-Resistant Pathway Sensitizes Glioblastomas to Anti-Lipogenic Therapy  

UK PubMed Central (United Kingdom)

Glioblastoma, the most common malignant brain tumor, is among the most lethal and difficult cancers to treat. Although epidermal growth factor receptor (EGFR) mutations are frequent in glioblastoma,...Full Text Available

285

Dynamic Chromatin Localization of Sirt6 Shapes Stress- and Aging-Related Transcriptional Networks  

UK PubMed Central (United Kingdom)

The sirtuin Sirt6 is a NAD-dependent histone deacetylase that is implicated in gene regulation and lifespan control. Sirt6 can interact with the stress-responsive transcription factor NF-κB...Full Text Available

2011-06-01

286

Drift compression and final focus of intense heavy ion beams  

Energy Technology Data Exchange (ETDEWEB)

The longitudinal and transverse dynamics of a heavy ion fusion beam during the drift compression and final focus phase is studied. A lattice design with four time-dependent magnets is described that focuses the entire beam pulse onto a single focal point with the same spot size.

2003-05-01

287

Disfiguring Annular Sarcoidosis Improved by Adalimumab  

UK PubMed Central (United Kingdom)

Depending on the location, dermatoses can produce blemishes that severely impair quality of life and require highly effective treatment that is otherwise used for extensive skin involvement. We report...Full Text Available

288

Direct measurement of the alpha-epsilon transition stress and kinetics for shocked iron  

Energy Technology Data Exchange (ETDEWEB)

Iron undergoes a polymorphic phase transformation from alpha phase (bcc) to the epsilon phase (hcp) when compressed to stresses exceeding 13 CPa. Bccause the epsilon phase is denser than the alpha phase, a single shock wave is unstable and breaks up into an elastic wave, a plastic wave, and a phase transition wave. Examination of this structured wave coupled with various phase transformation models has been used to indirectly examine the transition kinetics. Recently, multimillion atom simulations (molecular dynamics) have been used to examine the shock-induced transition in single crystal iron illustrating an orientation dependence of the transition stress, mechanisms, and kinetics. The objective of the current work was to perform plate impact experiments to examine the shock-response of polycrystalline and single crystal iron with nanosecond resolution for impact stresses spanning the {alpha} - {epsilon} transition. The current data reveal an orientation ...

2009-01-01

289

Dimeric subunit stoichiometry of the human voltage-dependent proton channel Hv1  

UK PubMed Central (United Kingdom)

In voltage-gated Na+, K+, and Ca2+ channels, four voltage-sensor domains operate on a central pore domain in response to membrane voltage. In contrast, the voltage-gated...Full Text Available

2008-06-03

290

Differing in vitro Survival Dependency of Mouse and Rat NG2+ Oligodendroglial Progenitor Cells  

UK PubMed Central (United Kingdom)

NG2 chondroitin sulfate proteoglycan is a surface marker of oligodendroglial progenitor cells (OPCs) in various species. In contrast to well-studied rat OPCs, however, we found that purified...Full Text Available

2010-04-01

291

Dependency of Nitrate Reduction on Soluble Carbohydrates in Primary Leaves of Barley under Aerobic Conditions 1  

UK PubMed Central (United Kingdom)

Nitrate reduction was studied as a function of carbohydrate concentration in detached primary leaves of barley (Hordeum vulgare L. cv Numar) seedlings under aerobic conditions in light...Full Text Available

1984-07-01

292

Dependence of thermal responses of seeds on membrane transitions  

UK PubMed Central (United Kingdom)

Transitions at 28-32°C in membranes of many kinds of seeds influence their germination and subsequent growth. Changes at 28-32°C in the rates of loss of endogenous amino acids from imbibed...Full Text Available

1979-02-01

293

Dependence of fast reactor fuel burnup characteristics on nuclear data libraries  

International Nuclear Information System (INIS)

In the framework of the development of burnup calculation method for commercial fast reactors, a sensitivity analysis was carried out to clarify the dependence of fuel burnup characteristics on nuclear data libraries (NDLs). The following NDLs were compared: JEF-2.2, ENDF/B-VI Release 5, JENDL-3.2 and JENDL-3.3. The NDL-dependence of material balance for main heavy metal nuclides ("2"3"5U, "2"3"8U, "2"3"9Pu, "2"4"0Pu and "2"4"1Pu) was small, since the number densities at the end of one-cycle burnup did not change over 1 or 2% among the above-mentioned libraries. Relatively large differences were found for minor actinide nuclides, especially for "2"3"6U, "2"3"7Np, "2"4"2"mAm, "2"4"3Am and curium isotopes. The number densities for these nuclides after burning up showed remarkable NDL-dependence over 5% through 50%. A burnup sensitivity analysis system based on the generalized perturbation theory enabled us to find out ...

2005-04-01

294

Defective major histocompatibility complex class I expression on lymphoid cells in autoimmunity.  

UK PubMed Central (United Kingdom)

Lymphocytes from patients with insulin-dependent diabetes mellitus (IDDM), a chronic autoimmune disease, have recently been shown to have decreased surface expression of MHC class I antigens. Since...Full Text Available

1993-05-01

295

DNA Damage during G2 Phase Does Not Affect Cell Cycle Progression of the Green Alga Scenedesmus quadricauda  

UK PubMed Central (United Kingdom)

DNA damage is a threat to genomic integrity in all living organisms. Plants and green algae are particularly susceptible to DNA damage especially that caused by UV light, due to their light dependency...Full Text Available

296

Cytokinin-Dependent Photorespiration and the Protection of Photosynthesis during Water Deficit1[W][OA  

UK PubMed Central (United Kingdom)

We investigated the effects of PSARK∷IPT (for Senescence-Associated Receptor Kinase∷Isopentenyltransferase) expression and cytokinin production...Full Text Available

2009-07-01

297

Critical periods of vulnerability for the developing nervous system: evidence from humans and animal models.  

UK PubMed Central (United Kingdom)

Vulnerable periods during the development of the nervous system are sensitive to environmental insults because they are dependent on the temporal and regional emergence of critical developmental processes...Full Text Available

2000-06-01

298

Critical nucleus size for disease-related polyglutamine aggregation is repeat length dependent  

UK PubMed Central (United Kingdom)

Since polyglutamine (polyQ) aggregate formation has been implicated as playing an important role in expanded CAG repeat diseases, it is important to understand the biophysics underlying the...Full Text Available

2011-03-01

299

Contraction of the deuteron cluster in /sup 6/Li  

Energy Technology Data Exchange (ETDEWEB)

The dependence of the rms radius of the deuteron cluster in /sup 6/Li on the relative d-..cap alpha.. momentum was investigated on the basis of the three-body wave function given by Rai, Lehman, and Ghovanlou.

1981-05-01

300

Consumer preferences for electric vehicles. Final report  

Energy Technology Data Exchange (ETDEWEB)

A small-sample survey of consumer preferences for a second car - featuring both conventional and electric vehicle choices - indicates a proelectric bias. The potential of electric cars in the utility market largely depends on dramatic improvements in battery technology and the right mix of electricity and gasoline prices.

1986-06-01

301

Computer simulation of protein self-association during small-zone gel filtration. Estimation of equilibrium constants.  

UK PubMed Central (United Kingdom)

A simulation is developed that qualitatively describes the small-zone-gel-filtration behaviour of a reversibly associating protein. The results reflect the dependence of the apparent molecular weight...Full Text Available

1981-04-01

302

Computer Simulation of Geothermal Reservoirs.  

Science.gov (United States)

General balance laws and constitutive relations are developed for convective hydrothermal geothermal reservoirs. A fully interacting rock-fluid system is considered; typical rock-fluid interactions involve momentum and energy transfer, and the dependence ...

1975-01-01

303

Cold dark matter annihilations: A source of gamma rays and antiprotons  

Energy Technology Data Exchange (ETDEWEB)

Massive particle candidates for dark matter provide a potentially observable signature by virtue of their annihilations in the galactic halo at a known but model-dependent rate. Possible signatures are described, including cosmic ray antiproton and gamma-ray production. (orig.).

1989-08-01

304

Cloning and Analysis of a Candida albicans Gene That Affects Cell Surface Hydrophobicity  

UK PubMed Central (United Kingdom)

The opportunistic pathogenic yeast Candida albicans exhibits growth phase-dependent changes in cell surface hydrophobicity, which has been correlated with adhesion to host tissues....Full Text Available

2001-06-01

305

Clinical outcomes and management of mechanism-based inhibition of cytochrome P450 3A4  

UK PubMed Central (United Kingdom)

Mechanism-based inhibition of cytochrome P450 (CYP) 3A4 is characterized by NADPH-, time-, and concentration-dependent enzyme inactivation, occurring when some drugs are converted by CYPs to reactive...Full Text Available

2005-03-01

306

Cholinergic Interneurons Mediate Fast VGluT3-Dependent Glutamatergic Transmission in the Striatum  

UK PubMed Central (United Kingdom)

The neurotransmitter glutamate is released by excitatory projection neurons throughout the brain. However, non-glutamatergic cells, including cholinergic and monoaminergic neurons, express markers that...Full Text Available

307

Characterization of the Key Step for Light-driven Hydrogen Evolution in Green Algae*  

UK PubMed Central (United Kingdom)

Under anaerobic conditions, several species of green algae perform a light-dependent hydrogen production catalyzed by a special group of [FeFe] hydrogenases termed HydA. Although highly interesting...Full Text Available

2009-12-25

308

Changes in Skeletal Mineral in Patients on Prolonged Maintenance Dialysis  

UK PubMed Central (United Kingdom)

The measurement of bone loss in patients undergoing maintenance dialysis over a period of two and a half years is reported. The tendency to lose bone is a likely event in renal failure, but depends...Full Text Available

1973-12-01

309

Cell proliferation depends on mitochondrial Ca2+ uptake: inhibition by salicylate  

UK PubMed Central (United Kingdom)

Store-operated Ca2+ entry (SOCE) is a ubiquitous Ca2+ influx pathway involved in control of multiple cellular and physiological processes including cell proliferation. Recent evidence...Full Text Available

2006-02-15

310

Catabolite Repression of the Citrate Fermentation Genes in Klebsiella pneumoniae: Evidence for Involvement of the Cyclic AMP Receptor Protein  

UK PubMed Central (United Kingdom)

Klebsiella pneumoniae is able to grow anaerobically with citrate as a sole carbon and energy source by a fermentative pathway involving the Na+-dependent citrate...Full Text Available

2001-09-01

311

Calcium/Calmodulin-Dependent Protein Kinase II Mediates Hippocampal Glutamatergic Plasticity During Benzodiazepine Withdrawal  

UK PubMed Central (United Kingdom)

Benzodiazepine withdrawal anxiety is associated with potentiation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptor (AMPAR) currents in hippocampal CA1 pyramidal...Full Text Available

2010-08-01

312

Calcium Effects on Stomatal Movement in Commelina communis L. 1  

UK PubMed Central (United Kingdom)

Stomatal movements depend on both ion influx and efflux; attainment of steady state apertures reflects modulation of either or both processes. The role of Ca2+ in those two processes was...Full Text Available

1988-07-01

313

Breakdown of the Blood-Brain Barrier during Tick-Borne Encephalitis in Mice Is Not Dependent on CD8+ T-Cells  

UK PubMed Central (United Kingdom)

Tick-borne encephalitis (TBE) virus causes severe encephalitis with serious sequelae in humans. The disease is characterized by fever and debilitating encephalitis that can progress to chronic illness...Full Text Available

314

Boundary value problem for an elliptic equation with rapidly oscillating coefficients in a rectangle  

British Library Electronic Table of Contents (United Kingdom)

An elliptic equation in a rectangle with coefficients depending on a fast variable and with its period being a small parameter is considered. An asymptotic expansion of the solution up to an arbitrary degree of the small parameter is constructed and substantiated by applying the two-scale expansion method.

2011-01-01

315

Blood Group A Antigen Is a Coreceptor in Plasmodium falciparum Rosetting  

UK PubMed Central (United Kingdom)

The malaria parasite Plasmodium falciparum utilizes molecules present on the surface of uninfected red blood cells (RBC) for rosette formation, and a dependency on ABO antigens has...Full Text Available

2000-05-01

316

Biotransformation of Explosives by the Old Yellow Enzyme Family of Flavoproteins  

UK PubMed Central (United Kingdom)

Several independent studies of bacterial degradation of nitrate ester explosives have demonstrated the involvement of flavin-dependent oxidoreductases related to the old yellow enzyme (OYE) of yeast....Full Text Available

2004-06-01

317

Bioaccumulation and toxicity of selenium compounds in the green alga Scenedesmus quadricauda  

UK PubMed Central (United Kingdom)

BackgroundSelenium is a trace element performing important biological functions in many organisms including humans. It usually affects organisms in a strictly dosage-dependent manner...Full Text Available

318

BOOKMARKS:  

Wastenet

Secretariat of the Basel Convention United Nations Office at Geneva ...such as public utilities, waste disposal sites, large energy dependent facilities including factories, institutions (hospitals, ...it provides immediate identification of PCB wastes, informs company officials of any special handling or disposal techniques

319

Average output lasing power of a He-Ne laser as a function of the modulation frequency of resonator losses  

Science.gov (United States)

The frequency dependence of the lasing power of a He-Ne laser was studied using the electrooptic effect in a KDP crystal. The gain profile of the power curve was found to differ noticeably between the high-frequency and low-frequency edges. (AIP). (AIP)

1976-09-01

320

Auxin Transport Is Required for Hypocotyl Elongation in Light-Grown but Not Dark-Grown Arabidopsis1  

UK PubMed Central (United Kingdom)

Many auxin responses are dependent on redistribution and/or polar transport of indoleacetic acid. Polar transport of auxin can be inhibited through the application of phytotropins such as 1-naphthylphthalamic...Full Text Available

1998-02-01

321

Auditing the Management of Vaccine-Preventable Disease Outbreaks: The Need for a Tool  

UK PubMed Central (United Kingdom)

Public health activities, especially infectious disease control, depend on effective teamwork. We present the results of a pilot audit questionnaire aimed at assessing the quality of public health services...Full Text Available

322

Asymmetrical Effects of Adaptation to Left and Right Shifting Prisms Depends on Pre-Existing Attentional Biases  

UK PubMed Central (United Kingdom)

Proposals that adaptation with left-shifting prisms induces neglect-like symptoms in normal individuals rely on a dissociation between the post-adaptation performance of individuals trained...Full Text Available

2010-09-01

323

Association Analysis of the Tryptophan Hydroxylase 2 Gene Polymorphisms in Patients with Methamphetamine Dependence/Psychosis  

UK PubMed Central (United Kingdom)

There is a growing evidence that serotoninergic systems modulate dopaminergic neurotransmission. We analyzed the association between the variations in the brain tryptophan hydroxylase 2 (TPH2)...Full Text Available

2011-03-01

324

Association Analysis of Nuclear Receptor Rev-erb Alpha Gene (NR1D1) and Japanese Methamphetamine Dependence  

UK PubMed Central (United Kingdom)

Several investigations suggested abnormalities in circadian rhythms are related to the pathophysiology of psychiatric disorders, including drug addiction. Recently, orphan nuclear receptor rev-erb alpha...Full Text Available

2011-03-01

325

Antihyperglycemic action of isoferulic acid in streptozotocin-induced diabetic rats  

UK PubMed Central (United Kingdom)

Wistar rats with streptozotocin-induced diabetes (STZ-diabetic rats), which is similar to human insulin-dependent diabetic mellitus (IDDM), were employed to investigate...Full Text Available

2000-02-01

326

Anti-inflammatory effects of liquiritigenin as a consequence of the inhibition of NF-?B-dependent iNOS and proinflammatory cytokines production  

UK PubMed Central (United Kingdom)

Background and purpose:Glycyrrhizae radix has been widely used as a cytoprotective, plant-derived medicine. We have identified a flavanoid, liquiritigenin, as an...Full Text Available

2008-05-01

327

Agonist-dependent up-regulation of thyrotrophin-releasing hormone receptor protein.  

UK PubMed Central (United Kingdom)

To study the effect of agonist on the TRH (thyrotrophin-releasing hormone) receptor protein, an epitope-tagged receptor was stably expressed in HEK-293 cells (human embryonic kidney 293 cells) and receptor...Full Text Available

2004-06-15

328

Age-dependent changes in Ca2+ homeostasis in peripheral neurones: implications for changes in function  

UK PubMed Central (United Kingdom)

Calcium ions represent universal second messengers within neuronal cells integrating multiple cellular functions, such as release of neurotransmitters, gene expression, proliferation, excitability,...Full Text Available

2007-06-01

329

Adsorption-introduced MC simulation technique for segregation studies in Pd-Ag nanoparticles  

Science.gov (United States)

We report here a new approach to introduce the effect of chemisorption in the Monte-Carlo simulation procedure for studying the segregation behaviour in bimetallic nanoparticles at low pressures. A coordination-dependent pair interaction energy is constructed in terms of partial bond energies and the exchange energy where the partial bond energy can be empirically calculated from the experimental values of dimer energy, the pressure-dependent surface energy and the bulk cohesive energy of the constituent metals. The advantage of this procedure is the ability to estimate the pressure-dependent surface composition of the nanoparticles. The method has been applied to oxygen-adsorbed Pd-Ag systems; and it is found that while Ag segregate in clean particles, at higher oxygen pressures Pd atoms segregate to the surface. The present technique has been argued to be suitable for higher pressures (>10-5Torr) when coverage cannot ...

2000-09-01

330

Activity-Dependent Augmentation of Spontaneous Neurotransmission during Endoplasmic Reticulum Stress  

UK PubMed Central (United Kingdom)

The endoplasmic reticulum (ER) is an essential cellular compartment responsible for Ca2+ sequestration, signaling, protein translation, folding as well as transport. Several acute...Full Text Available

2010-05-26

331

Accretion disks  

Science.gov (United States)

Derivations are made for the mass and the mass-turnover time scale of an accretion disk as a function of the accretion rate, the observed disk radius, the non-viscous disk radius, and two parameters. These parameters depend on the effectiveness of viscosity and tidal angular momentum loss. Application is made to DQ Herculis.

1983-01-01

332

Acamprosate and naltrexone treatment effects on ethanol and sucrose seeking and intake in ethanol-dependent and nondependent rats  

UK PubMed Central (United Kingdom)

RationaleTwo pharmacotherapies are approved for treating alcohol craving (acamprosate and naltrexone), but both have shown mixed findings in animals and humans.Full Text Available

2009-06-01

333

Ab binding alters gene expression in Cryptococcus neoformans and directly modulates fungal metabolism  

UK PubMed Central (United Kingdom)

Abs facilitate humoral immunity via the classical mechanisms of opsonization, complement activation, Ab-dependent cellular cytotoxicity, and toxin/viral neutralization. There is also evidence that some...Full Text Available

2010-04-01

334

ATM-Dependent Phosphorylation of ATF2 Is Required for the DNA Damage Response  

UK PubMed Central (United Kingdom)

SummaryActivating transcription factor 2 (ATF2) is regulated by JNK/p38 in response to stress. Here, we demonstrate that the protein kinase ATM phosphorylates ATF2 on serines...Full Text Available

2005-05-27

335

A predictive model of Health Related Quality of life of parents of chronically ill children: the importance of care-dependency of their child and their support system  

UK PubMed Central (United Kingdom)

BackgroundParents of chronically ill children are at risk for a lower Health Related Quality of Life (HRQoL). Insight in the dynamics of factors influencing parental HRQoL is necessary...Full Text Available

336

A novel Na+ channel splice form contributes to the regulation of an androgen-dependent social signal  

UK PubMed Central (United Kingdom)

Na+ channels are often spliced but little is known about the functional consequences of splicing. We have been studying the regulation of Na+ current inactivation in an...Full Text Available

2008-09-10

337

A membrane-associated progesterone-binding protein, 25-Dx, is regulated by progesterone in brain regions involved in female reproductive behaviors  

UK PubMed Central (United Kingdom)

The ventromedial hypothalamus (VMH) plays a central role in the regulation of the female reproductive behavior lordosis, a behavior dependent upon the sequential activation of receptors for the ovarian...Full Text Available

2000-11-07

338

A Longitudinal Study of Medicaid Coverage for Tobacco Dependence Treatments in Massachusetts and Associated Decreases in Hospitalizations for Cardiovascular Disease  

UK PubMed Central (United Kingdom)

BackgroundInsurance coverage of tobacco cessation medications increases their use and reduces smoking prevalence in a population. However, uncertainty about the impact of this coverage...Full Text Available

2010-12-01

339

A Kinetic Model of Dopamine- and Calcium-Dependent Striatal Synaptic Plasticity  

UK PubMed Central (United Kingdom)

Corticostriatal synapse plasticity of medium spiny neurons is regulated by glutamate input from the cortex and dopamine input from the substantia nigra. While cortical stimulation alone results in long-term...Full Text Available

2010-02-01

340

A Hyperactive NAD(P)H:Rubredoxin Oxidoreductase from the Hyperthermophilic Archaeon Pyrococcus furiosus  

UK PubMed Central (United Kingdom)

NAD(P)H:rubredoxin oxidoreductase (NROR) has been purified from the hyperthermophilic archaeon Pyrococcus furiosus. The enzyme is exceedingly active in catalyzing the NADPH-dependent...Full Text Available

1999-09-01

341

A Hybrid Strategy of Offline Adaptive Planning and Online Image Guidance for Prostate Cancer Radiotherapy  

UK PubMed Central (United Kingdom)

The offline adaptive radiotherapy (ART) has been used to effectively correct and compensate the prostate motion and reduce the required margin. The efficacy depends on the characteristics of...Full Text Available

2010-04-21

342

A History of Spike-Timing-Dependent Plasticity  

UK PubMed Central (United Kingdom)

How learning and memory is achieved in the brain is a central question in neuroscience. Key to today’s research into information storage in the brain is the concept of synaptic plasticity, a...Full Text Available

343

Thermal transfer augmentation by electroconvection  

Energy Technology Data Exchange (ETDEWEB)

Measurements of the rate of heat transfer, enhanced by electroconvection, between two parallel plates have been carried out. Results show that the non-dimensional heat flux, or the Nusselt number, increases when an electric field acts on an injected space charge within the insulating liquid. The motion of the liquid depends on the electrical forces (Coulomb force) and the buoyancy effects have little or no influence. This is evident from steady state and time dependent results which show that for a given voltage, the Nusselt number takes the same value no matter what the flux of heat supplied to the bottom plate.

1987-09-01

344

The onset conditions of enhancement of ice accumulation associated with heat-conducting plates located perpendicularly to heat-transfer surfaces; Part 1: Analysis for still water  

Energy Technology Data Exchange (ETDEWEB)

An analytical study of the ice-formation process associated with heat-conducting plates located perpendicularly to isothermally heated and cooled surfaces with some clearance is presented. It is proposed that the onset conditions, which describe whether the ice-volume fraction in a steady state is greater than or less than that without heat-conducting plates, are defined by the dimensionless distances between the heated/cooled walls and the heat-conducting plates. It is shown that the onset conditions are dependent on the pitch and the thickness of the heat-conducting plates and are less dependent on the thermal conductivity of the plates.

1994-07-01

345

The fluorescence properties and NMR analysis of protopine and allocryptopine  

International Nuclear Information System (INIS)

The fluorescence properties of protopine and allocryptopine in aqueous and organic environments are described for the first time. The fluorescence of alkaloids and their pH-dependent interconversion to cationic forms (transannular interaction) were studied using steady-state and time-resolved fluorescence techniques. For the analysis of tricyclic base and cis/trans tetracyclic cations of the alkaloids, NMR and X-ray crystallography were used. - Highlights: ? We describe fundamental fluorescence characteristics of alkaloids protopine and allocryptopine. ? We analyzed the pH-dependent transitions and cis/trans isomerization. ? These two alkaloids can be better distinguished by their fluorescence decay characteristics. ? The fluorescence parameters are related to the NMR and crystallographic structural data.

2011-07-01

346

The anisotropy of the Curie-Weiss law in dysprosium  

International Nuclear Information System (INIS)

In the paramagnetic region T > 178 K the paramagnetic susceptibility, chi, of Dy was measured as a function of temperature and orientation of the applied magnetic field with respect to the c-axis. For magnetic fields parallel and perpendicular to the c-axis the temperature dependence of chi can be represented by Curie-Weiss laws whereas for arbitrary orientations significant deviations from a Curie-Weiss behaviour were found. The measured anisotropy of the paramagnetic Curie temperatures and of the Curie-Weiss constants is shown to depend mainly on the magnetocrystalline energy and an anisotropic g-factor. (Auth.).

1979-10-01

347

Temperature dependence of molar excess volumes for the dimethyl sulfoxide + thiophene system and thermal expansion coefficients between 293. 15 and 313. 15 K  

Energy Technology Data Exchange (ETDEWEB)

Densities were measured with a vibrating-tube densimeter for binary mixtures of dimethyl sulfoxide + thiophene at temperatures from 293.15 to 313.15 K as a function of composition. Molar excess volumes V[sup E] for the mixtures, determined from the density data, are negative and become more negative with an increase in temperature. The coefficients of thermal expansion were also evaluated from the temperature dependence of the density.

1993-04-01

348

Temperature Dependences of Leakage Currents of ZnO Varistors Doped with Rare-Earth Oxides  

British Library Electronic Table of Contents (United Kingdom)

Rare-earth oxides are doped into ZnO varistors as grain growth inhibitors for increasing the varistors' voltage gradients. However, their leakage currents become large and their nonlinear coefficients decrease at the same time. The reasonable explanation for such a phenomenon has not yet been available. In this paper, the temperature dependences of varistor samples' leakage currents are investigated, which reveal that the increased leakage currents of ZnO varistors with Y2O3 doping are mainly due to the bypass paths through the intergranular materials at grain corners.

2010-01-01

349

Species dependence of the emittances of sputter-generated negative ion beams  

Energy Technology Data Exchange (ETDEWEB)

We report experimental evidence of a previously unseen species-dependent effect in the transverse emittances of momentum analysed /sup 28/Si/sup -/, /sup 58/Ni/sup -/ and /sup 197/Au/sup -/ ion beams generated by caesium ion sputtering. The high-resolution emittance measurement techniques employed in this work have enabled us to estimate the energy spreads of these ion beams; differences in the widths of the energy distributions are the origin of the observed differences in emittances of the ion beams investigated. (author).

1989-04-14

350

Radiation hardening characterization of a VDMOS developed at CAS institute of microelectronics  

International Nuclear Information System (INIS)

Total dose irradiation effects on a VDMOS developed at Institute of Microelectronics, CAS were investigated, particularly the electric parameter changes under different bias conditions. It was found that the breakdown voltage degradation by the irradiation depended mainly on the drain bias, whereas the threshold voltage degradation depended mainly on the gate bias. Thus, an innovative and effective method to domestic VDMOS total dose ionization characterization is that threshold voltage radiation hardening characterization should be tested on gate bias condition, and the breakdown voltage radiation hardening characterization, be tested on the drain bias. (authors)

2008-08-01

351

RADSOLVER: a computer program for calculating spectrally-dependent radiative heat transfer in solar cavity receivers  

Energy Technology Data Exchange (ETDEWEB)

RADSOLVER is a computer program which calculates the radiation energy transport in cavity type receivers having an arbitrary number of apertures through which collimated beams of solar radiation enter. In contrast to the common assumption of gray (or semi-gray) surfaces used in the modeling of radiation transport, RADSOLVER accounts for the wavelength-dependence of emission, absorption and reflection with a band model of the radiative properties. It is intended that this report serve both as an instruction manual for the use of the RADSOLVER code and a vehicle for presenting the underlying theory. Illustrative examples along with input and output are presented.

1981-09-01

352

Quark-hadron duality in structure functions  

Energy Technology Data Exchange (ETDEWEB)

I review recent developments in quark-hadron duality in inclusive electron-nucleon scattering. Matrix elements of twist-4 operators extracted from moments of the spin-dependent g1 structure function suggest that duality violating higher twists are small above Q2 {approx} 1 GeV2. The x dependence of local duality is analyzed within a quark model framework, and mechanisms are identified for spin-flavor symmetry breaking which underpin the behavior of structure functions at large x.

2004-10-01

353

Practical measurement of diffusion constants in sintered zirconias by using a light-scattering method  

Energy Technology Data Exchange (ETDEWEB)

A practical method to determine the ionic diffusion coefficient and activation energy by using quasielastic light scattering (QELS) is presented. It is shown that a temperature dependence curve of the QELS intensity at a fixed frequency can be well fitted by Jonscher's formula and that the diffusion parameters can be obtained from this curve fitting. This method is successfully applied not only to crystals with high optical quality, as reported earlier, but also to opaque ceramics, which are more important than the crystals from a practical point of view. The composition dependence of the ionic diffusion coefficient is studied in sintered YbSZ to show the usefulness of this method.

1991-03-01

354

Polythermal study of the M(ClO_4)_2-H_2O systems, where M"2 = Mg"2"+, Ca"2"+, Sr"2"+, Ba"2"+  

International Nuclear Information System (INIS)

Crystallization points of aqueous solution of the systems M(ClO_4)_2-H_2O (M"2 = Mg"2"+, Ca"2"+, Sr"2"+, Ba"2"+), depending on the salt concentration, were identified by visual-polythermal method. Relying on model notions on the structure of the electrolyte solutions, specific features of strontium perchlorate solubility polytherm and concentration dependence of the relative dynamic viscosity of the salt aqueous solutions are discussed

2005-03-01

355

Polaron model of the electronic spectrum and the superconductivity of compounds having the A-15 structure  

Energy Technology Data Exchange (ETDEWEB)

The existence of a narrow peak in the electronic density of states in A-15 compounds is explained by a strong electron--phonon interaction that leads to the polaron narrowing of the band. An analytic expression relating the transition temperature T/sub c/ to the phonon spectrum is derived under the assumption of a weak and an intermediate-strength coupling. The model allows the explanation of the correlation of T/sub c/ with the number of electrons per atom, the temperature dependence of the resistance, the magnitude and temperature dependence of the magnetic susceptibility, and the electronic specific heat.

1983-02-01

356

Photon-assisted spin-polarized transport in carbon nanotubes with impurities  

International Nuclear Information System (INIS)

Impurity effects on the photon-assisted spin-polarized transport through armchair carbon nanotubes connected with ferromagnetic leads are investigated theoretically. The impurity induces one resonant state whose position depends on the impurity strength, which can break the electron-hole symmetry. Whether the impurity suppresses or enhances the spin-coherent current depends on the nanotube length. When the microwave fields are applied on the nanotube, additional small side peaks caused by the photon-assisted tunneling are found. With increasing the impurity strength, one new current peak appears under the influence of both the microwave fields and the impurity.

2006-12-25

357

Mutual recombination and clusterization effect of the vacancy and interstitial barriers on radiation hardening materials  

British Library Electronic Table of Contents (United Kingdom)

There is proposed the nonlinear model of dose dependence saturation of the yield strength on the base of the vacancy and interstitial barrier interaction in this work. Processes of mutual recombination of vacancy and interstitial barriers and formation of vacancy and interstitial clusters are taken into consideration. In the framework of the model, the analytical equations corresponding to the evolution of the barrier densities and yield strength are obtained. It is shown that the yield strength of irradiated materials decreases with the increasing intensity of barrier recombination processes, the dependence being nonlinear. Also it is shown that the model is valid both for low doses and large doses on the stage of radiation hardening.

2009-01-01

358

Magnetic susceptibility of the A-15 compound system (Vsub(1-x)Crsub(x))_3Si  

International Nuclear Information System (INIS)

The magnetic susceptibility of single and polycrystalline samples of the A-15 compounds (Vsub(1-x)Crsub(x))_3Si (0 <= x <= 1) is measured at temperatures between 4.2 and 320 K. The magnitude and the temperature dependence of the susceptibility diminish with increasing Cr concentration. Applying a peak model for the density of electronic states it is found that the change of the temperature dependence of the susceptibility with increasing Cr concentration is caused mainly by broadening of the peak in the density of electronic states. (author).

359

K_#beta#/K_#alpha# X-ray intensity ratio following K-electron capture and radioisotope excitation  

International Nuclear Information System (INIS)

The K_#beta#/K_#alpha# X-ray intensity ratios are measured for Mn and Fe and for six other elements with Z lying in the range 49<=Z<=82 following electron capture decay and photon excitation using "2"4"1Am and "5"7Co sources. High-resolution Si(Li) and HpGe detector systems were used in the experiments. The dependence of K_#beta#/K_#alpha# values on the mode of excitation in the case of Mn and Fe is attribuited to the chemical effects, while no such dependence is found for the high-Z elements.

1987-01-01

360

Information detective quantum efficiency of X-ray film-intensifier foil systems  

Energy Technology Data Exchange (ETDEWEB)

The capability of screen-film combinations of detection and representation of information is described by the detective quantum efficiency (DQE). The DQE may be calculated from the sensitivity, the gradient of the characteristic curve, the modulation transfer function and the Wiener spectrum. These parameters have been determined for fourteen screen-film combinations and the DQE's have been calculated. It is shown that the low frequency region the DQE does not depend on spatial frequency. This constant level of DQE is mostly dependent on the absorbance of the screens. Consequences from this fact, as well for the manufacturer as for the user of the screens, are discussed.

1988-04-01

361

Information detective quantum efficiency of X-ray film-intensifier foil systems  

International Nuclear Information System (INIS)

The capability of screen-film combinations of detection and representation of information is described by the detective quantum efficiency (DQE). The DQE may be calculated from the sensitivity, the gradient of the characteristic curve, the modulation transfer function and the Wiener spectrum. These parameters have been determined for fourteen screen-film combinations and the DQE's have been calculated. It is shown that the low frequency region the DQE does not depend on spatial frequency. This constant level of DQE is mostly dependent on the absorbance of the screens. Consequences from this fact, as well for the manufacturer as for the user of the screens, are discussed. (orig.).

362

Formation and stability of self-assembled coherent islands in highly mismatched heteroepitaxy  

CERN Document Server

We study the energetics of island formation in Stranski-Krastanow growth within a parameter-free approach. It is shown that an optimum island size exists for a given coverage and island density if changes in the wetting layer morphology after the 3D transition are properly taken into account. Our approach reproduces well the experimental island size dependence on coverage, and indicates that the critical layer thickness depends on growth conditions. The present study provides a new explanation for the (frequently found) rather narrow size distribution of self-assembled coherent islands.

1999-01-01

363

Fe clusters on Ni and Cu: size and shape dependence of the spin moment  

Energy Technology Data Exchange (ETDEWEB)

We present ab-initio calculations of the electronic structure of small Fe clusters (1-9 atoms) on Ni(001), Ni(111), Cu(001) and Cu(111) surfaces. Our focus is on the spin moments and their dependence on cluster size and shape. We derive a simple quantitative rule that relates the moment of each Fe atom linearly to its coordination number. Thus, for an arbitrary Fe cluster the spin moment of the cluster and of the individual Fe atoms can be readily found if the positions of the atoms are known. (orig.)

2006-01-01

364

Experimental Study of Plasma-Surface Interaction and Material Damage Relevant to ITER Type I Elms  

International Nuclear Information System (INIS)

The paper presents experimental investigations of main features of plasma surface interaction and energy transfer to the material surface in dependence on plasma heat loads. The experiments were performed with QSPA repetitive plasma pulses of the duration of 0.25 ms and the energy density up to 2.5 MJ/m2. Surface morphology of the targets exposed to QSPA plasma screams is analyzed. Relative contribution of the Lorentz force and plasma pressure gradient to the resulting surface profile is discussed. development of cracking on the tungsten surface and swelling of the surface are found to be in strong dependence on initial temperature of the target.

2006-01-01

365

Emission of photons by electrons and positrons passing through a thin single crystal  

Energy Technology Data Exchange (ETDEWEB)

We consider the radiation of particles (electrons and positrons) undergoing planar channeling in a single crystal of small thickness L. We show that for Lapprox...pi..b/theta/sub L/, where b is the lattice constant and theta/sub L/ is the Lindhard angle, in addition to the principal maxima of spontaneous radiation of channeled particles in the spectrum there are additional interference maxima, and the positions of all maxima of the radiation intensity depend on L. We discuss the dependence of the intensity of radiation at various frequencies on the crystal thickness.

1984-07-01

366

Effective mass of heavy holes in diamond-like semiconductors  

Science.gov (United States)

Nonparabolicity of the heavy hole band in diamond-like semiconductors, which occurs within the framework of the three band model with the perturbation from the other bands taken into account according to the Loewdin procedure, is studied. A direct dependence of nonparabolicity on the band anisotropy (caused by the different effect of Gamma/sub 15c/ and Gamma/sub 12c/ bands) and the inverse dependence on the magnitude of the spin-orbit splittiing is established. A connection between the effective mass of heavy holes and their energy is obtained, which is valid for the majority of diamond-like semiconductors, except for materials with a very strong nonparabolicity of the band of silicon type

1987-08-01

367

Effective mass of heavy holes in diamond-like semiconductors  

International Nuclear Information System (INIS)

Nonparabolicity of the heavy hole band in diamond-like semiconductors, which occurs within the framework of the three band model with the perturbation from the other bands taken into account according to the Loewdin procedure, is studied. A direct dependence of nonparabolicity on the band anisotropy (caused by the different effect of Gamma/sub 15c/ and Gamma/sub 12c/ bands) and the inverse dependence on the magnitude of the spin-orbit splittiing is established. A connection between the effective mass of heavy holes and their energy is obtained, which is valid for the majority of diamond-like semiconductors, except for materials with a very strong nonparabolicity of the band of silicon type.

368

Coincidence measurements of M-shell excitation in slow Xe-Xe collisions  

Energy Technology Data Exchange (ETDEWEB)

Ion-photon and ion-Auger-electron coincidence measurements have been performed to study the impact parameter dependence of Xe M-shell excitation in 1.05 MeV Xe/sup 3 +/-Xe collisions. The experimental results are found to be consistent with the prediction of the molecular orbital model of atomic collisions. The average fluorescence yield for the Xe M shell is found to be strongly dependent on the impact parameter. This is ascribed to the production of highly charged Xe ions in close collisions.

1982-07-14

369

Coherent $\\omega$ photoproduction from nuclei and $\\omega$ properties in nuclear matter  

CERN Document Server

The coherent $\\omega$-meson photoproduction from nuclei is proposed as a phenomenological method to evaluate the momentum dependence of $\\omega$-meson mass shift and width in nuclear matter. We analyze available data on un-separated coherent and incoherent $\\omega$-meson photoproduction from nuclei and extract the imaginary part of the the complex forward $\\omega{N}$ scattering amplitude, which is proportional to the in-medium $\\omega$-meson width. The accuracy of the currently available data is not sufficient to evaluate the real part of forward $\\omega{N}$ scattering amplitude and reconstruct the momentum dependence of the mass shift of the $\\omega$-meson.

2002-01-01

370

Case for applying subnanosecond high-intensity, electrical pulses to biological cells.  

Science.gov (United States)

In this paper, model analysis into the time-dependent transmembrane potential at the outer cell membrane is presented, for applied high-intensity electric pulses having durations in the nanosecond range or smaller. It is argued that the frequency-dependent dielectric response of cell membranes could be used to advantage for stronger bioeffects by employing shorter pulses. Our model calculations predict faster transmembrane voltages and larger electroporation densities for a given external energy with pulse durations in the subnanosecond regime. This temporal regime would be used, for example, in the electrotherapy of mixed cell ensembles having different dielectric response properties. PMID:21937300

2011-10-01

371

Assessing NDVI Spatial Pattern as Related to Irrigation and Soil Salinity Management in Al-Hassa Oasis, Saudi Arabia  

British Library Electronic Table of Contents (United Kingdom)

Sustainability of irrigated agriculture in arid and semi arid lands depends, mainly on the level of soil salinity and the quality of irrigation water. Remotely sensed data can provide information about the extent of vegetated irrigated areas. Al-Hassa oasis, Saudi Arabia is probably the largest oasis in the world depends mostly on tapped ground water to irrigate mainly date palm groves for its economic survival. This study tried to investigate the extent of soil salinity and the quality of irrigation water and the relationship with vegetation growth, employing NDVI derived from Landsat satellite imagery.

2011-01-01

372

Application of self-adaptive procedure to the thermal problems analysis under steady-state and transient regimens; Aplicacao de procedimento auto-adaptativo na analise de problemas termicos no regime permanente e transiente  

Energy Technology Data Exchange (ETDEWEB)

This work describes a procedure for the adaptive time dependent Finite Element Method using an automatic mesh refinement (H-Version) that efficiently reduces estimated errors ( a posteriori) below pre-assigned limits. Classical model problem for steady-state heat transfer are investigated, and the results are compared with the analytical solution. Then some typical time-dependent problem are qualitatively analysed. (author) 10 refs., 7 figs.

1990-12-31

373

Analyzing Morphology and Thermal History of Polybutylene Terephthalate by THz Time-domain Spectroscopy  

British Library Electronic Table of Contents (United Kingdom)

We have measured the frequency-dependent dielectric function of semi-crystalline polybutylene terephthalate (PBT) in the terahertz region between 100?GHz and approximately 2.8?THz. A characteristic band is observed around 2.38?THz. The intensity of this band is a good indicator of the degree of crystallinity of the different samples. A potential assignment of this band is proposed, based on the comparison with spectroscopic data of the structurally very similar polyethylene terephtalate (PET). Furthermore, the frequency-dependent index of refraction of PBT reveals more insight about the morphology and different thermal history of the samples under investigation.

2011-01-01

374

Alpha-particle scattering from Ca-nuclei  

International Nuclear Information System (INIS)

The possibilities, advantages, and difficulties of determining nuclear matter densities by elastic scattering of alpha-particles are generally discussed. On the basis of particular experimental data - 104 MeV alpha-particle scattering from "4"0,"4"2,"4"4,"4"8Ca - a refined folded potential is introduced using a density-dependent alpha-nucleon-interaction and target nucleus densities described by Fourier-Bessel-series. Thereby, the total nucleon densities of these isotopes were determined with little model dependence. The resulting root-mean-square radii and density differences are compared with other experimental results obtained by different methods. (orig.).

1979-07-01

375

Expression of Na(+)-H+ exchange and ATP-dependent proton extrusion in growing rat IMCD cells  

Energy Technology Data Exchange (ETDEWEB)

As the last step of urinary acidification, the inner medullary collecting duct (IMCD) is thought to secrete protons into the tubular lumens by means of a H(+)-translocating adenosinetriphosphatase (H(+)-ATPase). However, recent studies have also shown the existence of Na(+)-H+ exchange activity in IMCD cells. Although the physiological function of the antiporter in IMCD cells is unknown, activation of Na(+)-H+ exchange in other cell-culture systems has been suggested to be closely associated with the process of cell growth. Thus presence of Na(+)-H+ exchange may relate to the growth phase of these cells. To examine intracellular pH (pHi) regulation in growing IMCD cells, we studied proton transport by Na(+)-dependent and Na(+)-independent mechanisms by microfluorimetry using the pHi-sensitive dye 2',7'-bis(carboxyethyl)-5,6-carboxyfluorescein acetoxymethyl ester (BCECF/AM). Actively growing cells, defined by (3H)thymidine incorporations, ...

1990-03-01

376

Ionization-chamber-dependent factors for calibration of megavoltage X-ray and electron beam therapy machines  

International Nuclear Information System (INIS)

When exposure-calibrated ionization chambers are used to calibrate megavoltage X-ray and electron beam therapy machines, the calibration factor can be divided into a chamber-dependent and a chamber-independent component. Until recently, only the chamber-independent part, which has been derived theoretically, has been used; the chamber-dependent component has been ignored. Recent experimental and theoretical considerations, however, have indicated that the dependent component must be taken into account and can affect the calibration by as much as 4%. The calibration can change due to (i) the thickness of the chamber wall, (ii) the chamber wall composition, i.e. whether the chamber is constructed of air-equivalent material, or tissue- or water-equivalent material, and (iii) the size of the chamber changing the displacement factor. Theoretical and experimental evidence indicates that the third factor varies from approximately ...

377

A model for the calculation of vent clearing transients in pressure suppression systems  

International Nuclear Information System (INIS)

For the layout of a pressure suppression system of a light water cooled reactor (boiling water reactor) it is important to know the time dependent behavior of the vent clearing transient after a loss-of-coolant accident for two main reasons: time of the end of the vent clearing transient influences strongly the pressure and temperature maxima in the drywell and wetwell. Time-dependent behavior of the vent clearing transient influences pressure loads in the condensation pool of the wetwell and therefore pressure induced stresses to the structure. The time-dependent behavior of the water masses in the vent pipes and wetwell are described by the basic equations for a nonstationary incompressible friction flow: momentum equation, continuity equation and a correlation for the variation of the state of the gas volume in the wetwell above the water level. After many algebraic operations and integrations along the flow path, a ...

1975-09-01

378

Wavelength-Dependent Differential Interference Contrast Microscopy: Selectively Imaging Nanoparticle Probes in Live Cells  

Energy Technology Data Exchange (ETDEWEB)

Gold and silver nanoparticles display extraordinarily large apparent refractive indices near their plasmon resonance (PR) wavelengths. These nanoparticles show good contrast in a narrow spectral band but are poorly resolved at other wavelengths in differential interference contrast (DIC) microscopy. The wavelength dependence of DIC contrast of gold/silver nanoparticles is interpreted in terms of Mie's theory and DIC working principles. We further exploit this wavelength dependence by modifying a DIC microscope to enable simultaneous imaging at two wavelengths. We demonstrate that gold/silver nanoparticles immobilized on the same glass slides through hybridization can be differentiated and imaged separately. High-contrast, video-rate images of living cells can be recorded both with and without illuminating the gold nanoparticle probes, providing definitive probe identification. Dual-wavelength DIC microscopy thus presents a new approach ...

2009-11-15

379

Viscoplasticity of elastomeric materials: experimental facts and constitutive modelling  

Energy Technology Data Exchange (ETDEWEB)

A characteristic of filled elastomers is their ability to undergo very large deformations without damaging their internal structure. The material behaviour is mainly elastic, however, elastomers show hysteresis effects leading to damping properties, which are quite important as regards their applications in various fields of mechanical engineering.A series of experiments (tension, torsion and combinations of both) was carried out on cylindrical bars made of a carbon-black filled rubber mixture. In addition to a pronounced nonlinear rate-dependence, relaxation and viscosity properties are observed as being influenced by the process histories.The behaviour of elastomeric materials is modelled on the basis of a free energy function and evolution equations for additional internal variables. Incorporating or disregarding the very small rate-independent hysteresis, the constitutive modelling may be classified under viscoplasticity or viscoelasticity. The constitutive ...

2001-03-01

380

Towards an accurate model of the redshift space clustering of halos in the quasilinear regime  

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 ...

2011-01-01

381

Time-dependent wavepacket calculations of molecular scattering from surfaces  

International Nuclear Information System (INIS)

An outline is given of time-dependent wavepacket methods as applied to calculations of molecular collisions with solid surfaces. The methods reviewed include numerical integration algorithms for the time-dependent Schroedinger equation, semiclassical wavepacket treatments, and approximations that treat some of the degrees-of-freedom quantum-mechanically and others classically. The computational and numerical characteristics of these methods are discussed, with emphasis on their particular advantages and relevance in the context of certain molecule/surface scattering problems. For the semiclassical and mixed quantal-classical treatments, the approximation errors and their physical origins are discussed. For the quantum wavepacket techniques a numerical error analysis is presented. The computational efficiency of the various algorithms is considered and examined in the context of several applications. The main focus is on diffractive scattering ...

1986-01-01

382

Time-dependent radiolytic yields at room temperature and temperature-dependent absorption spectra of the solvated electrons in polyols  

International Nuclear Information System (INIS)

The molar extinction coefficients at the absorption maximum of the solvated electron spectrum have been evaluated to be 900, 970, and 1000 mol-1?m2 for 1,2-ethanediol (12ED), 1,2-propanediol (12PD), and 1,3-propanediol (13PD), respectively. These values are two-third or three-fourth of the value usually reported in the published report. Picosecond pulse radiolysis studies have aided in depicting the radiolytic yield of the solvated electron in these solvents as a function of time from picosecond to microsecond. The radiolytic yield in these viscous solvents is found to be strongly different from that of the water solution. The temperature dependent absorption spectra of the solvated electron in 12ED, 12PD, and 13PD have been also investigated. In all the three solvents, the optical spectra shift to the red with increasing temperature. While the shape of the spectra does not change in 13PD, a widening on the blue side of the absorption band is observed in 12ED and ...

2007-02-01

383

Systems Biology Approach in Chlamydomonas Reveals Connections between Copper Nutrition and Multiple Metabolic Steps[C][W][OA  

Science.gov (United States)

In this work, we query the Chlamydomonas reinhardtii copper regulon at a whole-genome level. Our RNA-Seq data simulation and analysis pipeline validated a 2-fold cutoff and 10 RPKM (reads per kilobase of mappable length per million mapped reads) (~1 mRNA per cell) to reveal 63 CRR1 targets plus another 86 copper-responsive genes. Proteomic and immunoblot analyses captured 25% of the corresponding proteins, whose abundance was also dependent on copper nutrition, validating transcriptional regulation as a major control mechanism for copper signaling in Chlamydomonas. The impact of copper deficiency on the expression of several O2-dependent enzymes included steps in lipid modification pathways. Quantitative lipid profiles indicated increased polyunsaturation of fatty acids on thylakoid membrane digalactosyldiglycerides, indicating a global impact of copper deficiency on the photosynthetic apparatus. Discovery of a putative plastid copper chaperone ...

2011-04-01

384

Sucrose transport into stalk tissue of sugarcane  

Energy Technology Data Exchange (ETDEWEB)

The productivity of higher plants is, in part, dependent on transport of photosynthate from source to sink (in sugarcane, stalk) and upon its assimilation in cells of the sink tissue. In sugarcane, sucrose has been reported to undergo hydrolysis in the apoplast before uptake into the storage parenchyma, whereas recently, sucrose was reported to be taken up intact. This work was based on lack of randomization of ({sup 14}C)fructosyl sucrose accumulated after feeding tissue slices with this sugar. In this report, we present evidence from slices of stalk tissue that sucrose is taken up intact via a carrier-mediated, energy-dependent process. The evidence includes: (1) uptake of fluorosucrose, an analog of sucrose not subject to hydrolysis by invertase; (2) little or no randomization of ({sup 14}C) fructosyl sucrose taken up; (3) the presence of a saturable as well as a linear component of sucrose uptake; and (4) inhibition of both the saturable ...

1990-05-01

385

Study on the energy distribution of ion beams extracted from the sputter-type negative-ion source  

International Nuclear Information System (INIS)

The energy distribution of ion beams is important especially for low energy ion beam applications. The energy distributions of negative-ion beams produced through secondary ion emission by sputtering were measured and compared with theoretically estimated distributions by use of four different negative-ion production probability equations (modified surface ionization model, exponential velocity dependence model, and our modified exponential velocity dependence models (modified decaying factor model and combination model of velocity dependence and surface ionization)). In the measurements, the energy distributions of C"- and Ag"- beams had a peak at a few to several eV and the full width at half maximum were 15 eV and 11 eV, respectively. These results could be well explained by the estimated distributions by virtue of our combination model or the modified surface ionization model. copyright 1996 American Institute of ...

1995-10-23

386

Spectral dependence of absorption photoinduced in a Bi{sub 12}TiO{sub 20} crystal by 532-nm laser pulses  

Science.gov (United States)

The spectral dependences of absorption photoinduced in a pure bismuth titanium oxide crystal by 532-nm laser pulses are studied. It is shown that optical absorption in the crystal in the range from 492 to 840 nm increases with increasing exposure. The photoinduced absorption relaxes in the dark for more than 60 hours. A model of photoinduced absorption is proposed which assumes the population of two trap centres with the normal energy distribution law for the concentrations of electrons photoexcited from donors to the conduction band. This model well describes the spectral dependences of photoinduced absorption by using the average ionisation energies of the traps E{sub 1} = 1.60 eV and E{sub 2} = 2.57 eV. The model is used to estimate the increase in the photorefractive sensitivity of a bismuth titanium oxide crystal in the near IR region, which was earlier observed after exposing the crystal to visible radiation. It is predicted that the ...

2007-11-30

387

Spacetime constraints on accreting black holes  

International Nuclear Information System (INIS)

We study the spin dependence of accretion onto rotating Kerr black holes using analytic techniques. In its linear regime, angular momentum transport in MHD turbulent accretion flow involves the generation of radial magnetic field connecting plasma in a differentially rotating flow. We take a first principles approach, highlighting the constraint that limits the generation and amplification of radial magnetic fields, stemming from the transfer of energy from mechanical to magnetic form. Because the energy transferred in magnetic form is ultimately constrained by gravitational potential energy or Killing energy, the spin dependence of the latter allows us to derive spin-dependent constraints on the success of the accreting plasma to expel its angular momentum. We find an inverse relationship between this ability and black hole spin. If this radial magnetic field generation forms the basis for angular momentum transfer in ...

2009-06-15

388

Semiempirical model based on thermodynamic principles for determining 6 kW proton exchange membrane electrolyzer stack characteristics  

Energy Technology Data Exchange (ETDEWEB)

The performance of a 6 kW proton exchange membrane (PEM) electrolyzer was modeled using a semiempirical equation. Total cell voltage was represented as a sum of the Nernst voltage, activation overpotential and ohmic overpotential. A temperature and pressure dependent Nernst potential, derived from thermodynamic principles, was used to model the 20 cell PEM electrolyzer stack. The importance of including the temperature dependence of various model components is clearly demonstrated. The reversible potential without the pressure effect decreases with increasing temperature in a linear fashion. The exchange current densities at both the electrodes and the membrane conductivity were the coefficients of the semiempirical equation. An experimental system designed around a 6 kW PEM electrolyzer was used to obtain the current-voltage characteristics at different stack temperatures. A nonlinear curve fitting method was employed to determine the equation ...

2008-12-01

389

Salicylate Treatment Improves Age-Associated Vascular Endothelial Dysfunction: Potential Role of Nuclear Factor kB and Forkhead Box O Phosphorylation  

British Library Electronic Table of Contents (United Kingdom)

We hypothesized that I kappa B kinase (IKK)-mediated nuclear factor kappa B and forkhead BoxO3a phosphorylation will be associated with age-related endothelial dysfunction. Endothelium-dependent dilation and aortic protein expression/phosphorylation were determined in young and old male B6D2F1 mice and old mice treated with the IKK inhibitor, salicylate. IKK activation was greater in old mice and was associated with greater nitrotyrosine and cytokines. Endothelium-dependent dilation, nitric oxide (NO), and endothelial NO synthase phosphorylation were lower in old mice. Endothelium-dependent dilation and NO bioavailability were restored by a superoxide dismutase mimetic. Nuclear factor kappa B and forkhead BoxO3a phosphorylation were greater in old and were associated with increased express...

2011-01-01

390

Reconstruction of the activity of point sources for the accurate characterization of nuclear waste drums by segmented gamma scanning  

International Nuclear Information System (INIS)

This work improves the reliability and accuracy in the reconstruction of the total isotope activity content in heterogeneous nuclear waste drums containing point sources. The method is based on #chi#"2-fits of the angular dependent count rate distribution measured during a drum rotation in segmented gamma scanning. A new description of the analytical calculation of the angular count rate distribution is introduced based on a more precise model of the collimated detector. The new description is validated and compared to the old description using MCNP5 simulations of angular dependent count rate distributions of Co-60 and Cs-137 point sources. It is shown that the new model describes the angular dependent count rate distribution significantly more accurate compared to the old model. Hence, the reconstruction of the activity is more accurate and the errors are considerably reduced that lead to more reliable results. ...

2011-06-01

391

Pulsar Binary Birthrates with Spin-Opening Angle Correlations  

CERN Document Server

Empirical birthrate estimates for pulsar binaries depend on the fraction of sky subtended by the pulsar beam: the pulsar beaming fraction. This fraction depends on both the pulsar's opening angle and the misalignment angle between its spin and magnetic axes. Previous estimates use the average value for only two pulsars, i.e. PSRs B1913+16 and B1534+12. We explore how birthrate predictions depend on assumptions about opening angle and alignment, using empirically-motivated distributions to define an effective beaming correction factor, f_{b,eff}. For most known pulsars, we expect f_{b,eff} to be less than 6. We also calculate f_{b,eff} for PSRs J0737-3039A and J1141-6545, applying the currently available constraints for their beam geometry. Our median posterior birthrate predictions for tight PSR-NS binaries, wide PSR-NS binaries, and tight PSR-WD binaries are 89/Myr, 0.84/Myr, and 34/Myr, respectively. For pulsars with spin ...

2009-01-01

392

Photoluminescence linewidths in metalorganic vapor phase epitaxially grown ordered and disordered InAlGaP alloys  

International Nuclear Information System (INIS)

The dependence of the photoluminescent properties of In_0_._4_8(Al_yGa_1_-_y)_0_._5_2P alloys (0#<=#y#<=#0.5) on growth temperature and substrate misorientation off GaAs(100) has been studied. Samples were grown using low-pressure metalorganic vapor phase epitaxy. By studying the dependence of ordering behavior in InGaP as a function of substrate misorientation and growth temperature simultaneously, a very large range in low-temperature photoluminescence emission energy---135 meV---has been obtained. The photoluminescence linewidth exhibits a strong, continuous dependence on the extent of atomic ordering (the emission energy) in the alloys. The results indicate that inhomogeneity in the microstructure of the material (i.e., between ''ordered'' domains and the ''disordered'' matrix) is the dominant photoluminescence broadening mechanism. This investigation has allowed a significant optimization of the optical ...

393

Photoelectrochemistry of disordered passive films  

Energy Technology Data Exchange (ETDEWEB)

A theoretical model, which describes subband gap photoexcitation involving localized electronic states, was developed. The escape probability of a charge carrier trapped in a localized state is considered via Poole-Frenkel, direct tunneling, or phonon-assisted tunneling processes, as competing escape mechanisms. Photoelectrochemical experiments were performed on the passive films formed on zirconium and amorphous iron-zirconium alloys and on pure HfO/sub 2/ films and HfO/sub 2/ films implanted with varying concentrations of xenon. These films were found to possess some degree of disorder depending on the substrate, the thickness of the film, and the extent of implantation. The spectral dependence of the photocurrent in all of the films studied is considerably different from what was found for crystalline passive films. The potential dependence of the photocurrent yields Poole-Frenkel behavior. Reverse tunneling processes ...

1987-01-01

394

Performance evaluation for ML sequence detection in ISI channels with Gauss Markov Noise  

CERN Document Server

Inter-symbol interference (ISI) channels with data dependent Gauss Markov noise have been used to model read channels in magnetic recording and other data storage systems. The Viterbi algorithm can be adapted for performing maximum likelihood sequence detection in such channels. However, the problem of finding an analytical upper bound on the bit error rate of the Viterbi detector in this case has not been fully investigated. Current techniques rely on an exhaustive enumeration of short error events and determine the BER using a union bound. In this work, we consider a subset of the class of ISI channels with data dependent Gauss-Markov noise. We derive an upper bound on the pairwise error probability (PEP) between the transmitted bit sequence and the decoded bit sequence that can be expressed as a product of functions depending on current and previous states in the (incorrect) decoded sequence and the (correct) transmitted ...

2010-01-01

395

Parity-projected shell model Monte Carlo level densities for fp-shell nuclei  

International Nuclear Information System (INIS)

We calculate parity-dependent level densities for the even-even isotopes "5"8","6"2","6"6Fe and "5"8Ni and the odd-A nuclei "5"9Ni and "6"5Fe using the shell model Monte Carlo method. We perform these calculations in the complete fp-gds shell-model space using a pairing+quadrupole residual interaction. We find that, due to pairing of identical nucleons, the low-energy spectrum is dominated by positive parity states. Although these pairs break at around the same excitation energy in all nuclei, the energy dependence of the ratio of negative-to-positive parity level densities depends strongly on the particular nucleus of interest. We find equilibration of both parities at noticeably lower excitation energies for the odd-A nuclei "5"9Ni and "6"5Fe than for the neighboring even-even nuclei "5"8Ni and "6"6Fe.

2007-06-01

396

On the temperature dependence of the magnetic excitations  

International Nuclear Information System (INIS)

We compare experimental data for temperature dependence of the magnetic order parameter and the magnetic excitations (spin waves) in materials with a quenched orbital moment and a well-defined spin quantum number. It is observed that the thermal decrease of the two quantities proceeds according to the same analytical function of the type y(T)=1-cT"#epsilon# with an identical exponent #epsilon#. This power function applies not only asymptotically for T->0 but holds over a wide temperature range. The exponent #epsilon# is universal, i.e. independent of spin order type and lattice symmetry and depends only on the dimensionality of the relevant interactions and on whether the spin quantum number is integer or half-integer. The different T"#epsilon# functions are identified as representations of stable universality classes. The fact that order parameter and magnetic excitations follow the same T"#epsilon# function shows that the two quantities ...

2005-07-15

397

On the band gap dependence of refractive indices of some quaternary III-V and II-VI compounds of device interest  

International Nuclear Information System (INIS)

The credibility of the model proposed by Ghosh in predicting the refractive indices of mixed semiconductor crystals of technological importance within their miscibility range as a function of band gap is demonstrated. The high-frequency refractive indices of four quaternary alloys Al_xGa_1_-_x_-_yIn_yP (y = 0.49, 0 #<=# x #<=# 0.51), InSb_xAs_1_-_x_-_yP_y (y = 2.2x, 0 #<=# x #<=# 0.313, 0 #<=# y #<=# 0.638), Cd_xZn_1_-_x_-_yHg_ySe (x + y = 1, 0.153 #<=# x #<=# 0.684, 0.316 #<=# y #<=# 0.847), and CdS_1_-_x_-_ySe_xTe_y (x + y = 1, 0.15 #<=# x #<=# 0.93, 0.07 #<=# y #<=# 0.85) are calculated according to the relation n"2-1 = A/(E_g + B)"2 where A is an energy gap dependent constant and B is a constant depending on crystal ionicity. The calculated values show excellent agreement with the experimental data thus justifying the validity of the model.

398

Observed energy dependence of Fano factor in silicon at hard X-ray energies  

Energy Technology Data Exchange (ETDEWEB)

An experimental evaluation of the Fano factor F in silicon at hard X-ray energies (5.9-136.5 keV) has been performed by means of a low-noise, high charge collection efficiency silicon drift detector with on-chip electronics. A dependence of F from the detector temperature as well as from the energy of the X-ray photons has been found. Assuming a pair creation energy equal to 3.64 eV, at +20 deg. C the F factor was observed to vary from 0.124{+-}0.006 at 5.9 keV up to 0.159{+-}0.002 at 122 keV. At -35 deg. C, the change of F with respect to the photon energy was less remarkable but nevertheless statistically significant, from 0.123{+-}0.002 at 5.9 keV up to 0.134{+-}0.001 at 122 keV. To our knowledge, the present results represent the first experimental evidence of an energy dependence of the Fano factor in silicon at hard X-ray energies.

1999-03-01

399

Nanosized copper ferrite materials: Mechanochemical synthesis and characterization  

International Nuclear Information System (INIS)

Nanodimensional powders of cubic copper ferrite are synthesized by two-steps procedure of co-precipitation of copper and iron hydroxide carbonates, followed by mechanochemical treatment. X-ray powder diffraction, Moessbauer spectroscopy and temperature-programmed reduction are used for the characterization of the obtained materials. Their catalytic behavior is tested in methanol decomposition to hydrogen and CO and total oxidation of toluene. Formation of nanosized ferrite material is registered even after one hour of milling time. It is established that the prolonging of treatment procedure decreases the dispersion of the obtained product with the appearance of Fe2O3. It is demonstrated that the catalytic behavior of the samples depends not only on their initial phase composition, but on the concomitant ferrite phase transformations by the influence of the reaction medium. -- Graphical abstract: It is demonstrated that the catalytic behavior of the obtained copper ...

2011-05-01

400

Microscopic analysis of the /sup 88/Sr(p,p') reaction at E/sub p/ = 201. 5 MeV  

Energy Technology Data Exchange (ETDEWEB)

Differential cross sections for 201.5 MeV proton scattering form /sup 88/Sr were measured. From the analysis of the elastic data, no unique optical-model potential could be obtained, but the radial moments are well determined. In a macroscopic analysis of the collective states it turns out that if the optical potential and transition potential are chosen consistently, unambiguous potential deformation lengths can be obtained even though the optical potential is not unique. Taking into account the range and density dependence of the underlying effective interaction reliable neutron deformation lengths can be obtained. For inelastic transitions of various character microscopic distorted-wave calculations with a density-dependent interaction based on the Paris potential were performed. The nuclear structure was taken from one broken-pair calculations in a large model space, calibrated by (e,e') data. In general a good description is ...

1988-04-25

401

Microscopic analysis of the "8"8Sr(p,p') reaction at E_p = 201.5 MeV  

International Nuclear Information System (INIS)

Differential cross sections for 201.5 MeV proton scattering form "8"8Sr were measured. From the analysis of the elastic data, no unique optical-model potential could be obtained, but the radial moments are well determined. In a macroscopic analysis of the collective states it turns out that if the optical potential and transition potential are chosen consistently, unambiguous potential deformation lengths can be obtained even though the optical potential is not unique. Taking into account the range and density dependence of the underlying effective interaction reliable neutron deformation lengths can be obtained. For inelastic transitions of various character microscopic distorted-wave calculations with a density-dependent interaction based on the Paris potential were performed. The nuclear structure was taken from one broken-pair calculations in a large model space, calibrated by (e,e') data. In general a good description is obtained for ...

402

Measurements of single and double spin asymmetry in pp elastic scattering in the CNI region with a polarized atomic hydrogen gas jet target  

International Nuclear Information System (INIS)

Precise measurements of the single spin asymmetry AN, and the double spin asymmetry ANN, in proton-proton (pp) elastic scattering in the region of four-momentum transfer squared 0.0012 have been performed using a polarized atomic hydrogen gas jet target and the Relativistic Heavy Ion Collider (RHIC) polarized proton beam. We present measurements of AN and ANN at center-of-mass energies ?(s)=6.8 and 13.7 GeV. These spin-dependent observables are sensitive to the poorly known hadronic spin-dependent amplitudes. Comparing AN at different energies, a ?(s) dependence of the hadronic single spin-flip amplitude is suggested. A hadronic double spin-flip amplitude from the ANN data is consistent with zero within a 2-? level. We also present ??T, estimated from the measured ANN data. The results for ??T are consistent with zero. Our results provide significant constraints toward a comprehensive understanding of the reaction mechanism ...

2009-05-01

403

Market Mill Dependence Pattern in the Stock Market: Modeling of Predictability and Asymmetry via Multi-Component Conditional Distribution  

CERN Document Server

Recent studies have revealed a number of striking dependence patterns in high frequency stock price dynamics characterizing probabilistic interrelation between two consequent price increments x (push) and y (response) as described by the bivariate probability distribution P(x,y) [1,2,3,4]. There are two properties, the market mill asymmetries of P(x,y) and predictability due to nonzero z-shaped mean conditional response, that are of special importance. Main goal of the present paper is to put together a model reproducing both the z-shaped mean conditional response and the market mill asymmetry of P(x,y) with respect to the axis y=0. We develop a probabilistic model based on a multi-component ansatz for conditional distribution P(y|x) with push-dependent weights and means describing both properties. A relationship between the market mill asymmetry and predictability is discussed. A possible connection of the model to agent-based picture is ...

2007-01-01

404

Effects of interstitial clustering on transient enhanced diffusion of boron in silicon  

Energy Technology Data Exchange (ETDEWEB)

A simulation model for boron diffusion which takes into account the aggregation of the excess interstitials in clusters, and subsequently, the dissolution of these defects, is proposed. The interstitial supersaturation and generation rate are determined according to the classical theory of nucleation and growth of particles, in analogy with the precipitation of a new phase in heavily doped silicon. The clusters are considered as precipitates formed by interstitial Si atoms. The B diffusion is modelled on the basis of the dopant-interstitial pair diffusion mechanism. The clusters dissolution during annealing maintains nearly constant, for a long period, the interstitial supersaturation and the related enhancement of the boron diffusion. This gives a good account of the diffusion results over a large range of experimental conditions. Furthermore, this approach describes most of the behavior of the transient enhanced diffusion (TED), like the temperature dependence of ...

1997-11-01

405

Effects of epidermal growth factor on bone formation and resorption in vivo  

Energy Technology Data Exchange (ETDEWEB)

The effects of mouse epidermal growth factor (EGF) on bone formation and resorption were examined in male mice. EGF administration (2-200 ng.g-1.day-1 ip for 7 days) induced a dose-dependent rise in plasma EGF levels that remained within physiological range. Histomorphometric analysis of caudal vertebrae showed that EGF (20 and 200 ng.g-1.day-1) reduced the endosteal matrix and mineral appositional rates after 5 days of treatment as measured by double (3H)proline labeling and double tetracycline labeling, respectively. This effect was transitory and was not observed after 7 days of EGF administration. EGF administered for 7 days induced a dose-dependent increase in the periosteal osteoblastic and tetracycline double-labeled surfaces. At high dosage (200 ng.g-1.day-1) EGF administration increased the osteoclastic surface and the number of acid phosphatase-stained osteoclasts, although plasma calcium remained normal. The results show that EGF ...

1990-02-01

406

Effect of coal rank and mineral matter on gasification reactivity of coal char treated at high temperature; Netsushorishita sekitan char no gas ka tokusei ni taisuru tanshu oyobi kobutsushitsu no eikyo  

Energy Technology Data Exchange (ETDEWEB)

In the wide range from brown coal to anthracite, an investigation was made of effects of heat treatment on physical/chemical properties and of coal rank dependence. For the experiment, 12 kinds of coal samples were used, and for heat treatment, the fluidized bed heated by the electric furnace and the infrared-ray gold image furnace were used. To examine characteristics of the heat-treated coal char, conducted were oxygen gasification, TPD measurement, XRD measurement, alkali metal measurement, and pore distribution measurement. The following were obtained from the experiment. The gasification reaction rate of the char heat-treated in the temperature range between 900{degree}C to 1700{degree}C decreases with a rise of the temperature of heat treatment, and the degree of decrease in the rate depends on coal rank. The order of gasification rate between coal ranks depends on the temperature of heat treatment, and the lower the ...

1996-10-28

407

Distance-dependent interactions between gold nanoparticles and fluorescent molecules with DNA as tunable spacers  

International Nuclear Information System (INIS)

Using stoichiometrically controlled 1:1 functionalization of gold nanoparticles with fluorescent dye molecules in which the dye molecule is held away from the particle surface by a rigid DNA spacer allows precise determination of the distance-dependent effect of the metal nanoparticles on fluorescence intensity. Two dyes were studied, Cy3 and Cy5, with two sizes of nanoparticles, 5 and 10 nm. The larger the particle, the more quenching of the photoluminescence (PL) intensity, due to increased overlap of the dye's emission spectrum with the Au surface plasmon resonance. Fluorescence is quenched significantly for distances somewhat larger than the particle diameter, in good agreement with the predictions of an electrodynamics model based on interacting dipoles. The distance dependence of surface energy transfer behavior, i.e. quenching efficiency, is proportional to 1/d4, which involves no consideration of the size of the particle and the ...

2009-12-02

408

Crystalline beam ground state  

Energy Technology Data Exchange (ETDEWEB)

In order to employ molecular dynamics (MD) methods, commonly used in condensed matter physics, we have derived the equations of motion for a beam of charged particles in the rotating rest frame of the reference particle. We include in the formalism that the particles are confined by the guiding and focusing magnetic fields, and that they are confined in a conducting vacuum pipe while interacting with each other via a Coulomb force. Numerical simulations using MD methods has been performed to obtain the equilibrium crystalline beam structure. The effect of the shearing force, centrifugal force, and azimuthal variation of the focusing strength are investigated. It is found that a constant gradient storage ring can not give a crystalline beam, but that an alternating-gradient (AG) structure can. In such a machine the ground state is, except for one-dimensional (1-D) crystals, time dependent. The ground state is a zero entropy state, despite the ...

1993-06-11

409

Boron-Dependent Degradation of NIP5;1 mRNA for Acclimation to Excess Boron Conditions in Arabidopsis.  

Science.gov (United States)

Boron (B) is an essential plant micronutrient that is toxic at higher levels. NIP5;1 is a boric acid channel required for B uptake and growth under B deficiency. Accumulation of the NIP5;1 transcript is upregulated under B deficiency in Arabidopsis thaliana roots. To elucidate the mechanism of regulation, the 5' untranslated region (UTR) of NIP5;1 was tested for its ability to confer B-dependent regulation using ?-glucuronidase and green fluorescent protein as reporters. This analysis showed that the 5' UTR was involved in NIP5;1 transcript accumulation in response to B conditions. We also found that high-B conditions trigger NIP5;1 mRNA degradation and that the sequence from +182 to +200 bp in the 5' UTR is required for this mRNA destabilization. In the nip5;1-1 mutant background, a NIP5;1 complementation construct without the 5' UTR produced high levels of mRNA accumulation, increased B concentrations in tissues, and reduced growth under high-B conditions. These ...

2011-09-01

410

Behavioral effects of microwaves  

Energy Technology Data Exchange (ETDEWEB)

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

1980-01-01

411

Azimuth Quadrupole Systematics in Au-Au Collisions  

CERN Document Server

We have measured $p_t$-dependent two-particle number correlations on azimuth and pseudorapidity for eleven centralities of $\\sqrt{s_{NN}} = 62$ and 200~GeV Au-Au collisions at STAR. 2D fits to these angular correlations isolate the azimuth quadrupole amplitude, denoted $2 v_2^2 \\{ 2D \\} ( p_t )$, from localized same-side correlations. Event-plane $v_2 ( p_t )$ measurements within the STAR TPC acceptance can be expressed as a sum of the azimuth quadrupole and the quadrupole component of the same-side peak. $v_2 \\{ 2D \\} ( p_t )$ can be transformed to reveal quadrupole $p_t$ spectra which are approximately described by a fixed transverse boost and universal L\\'evy form nearly independent of centrality. A parametrization of $v_2 \\{ 2D \\} ( p_t )$ can be factored into centrality and $p_t$-dependent pieces with a simple $p_t$ dependence above 0.75 GeV/c. Results from STAR are compared to published data and model ...

2010-01-01

412

Analytical study on detailed void distributions inside BWR fuel bundle under turbine trip event considering time-dependent pin power distributions  

Energy Technology Data Exchange (ETDEWEB)

A one-way coupling system between the plant simulator TRAC/BF1-ENTREE and the subchannel code with the improved cross flow model, NASCA, has been developed. Based on a scenario of turbine trip tests in the Peach Bottom Unit 2, the wide and rapid reactivity insertion transient induced by the system pressure rise was calculated. The pin power distribution in hot bundles was re-constructed considering heterogeneity of the fuel bundle. When the neighboring control blade is withdrawn, NASCA predicted that the steady-state bundle exit void distribution was nearly flat with regardless of the pin power distribution. However, void distributions in the middle and lower bundle regions became complicated depending on the pin power and the two-phase flow regime in each subchannel. The pin power distribution rapidly changed according to traveling of control blades. However, influence in the void distribution was delayed and damped due to the fuel heat conduction. The detailed ...

2002-11-01

413

Development of detection methods for irradiated foods; development of immunological identification of irradiated foods  

Energy Technology Data Exchange (ETDEWEB)

Enzyme-linked Immunosorbent assay systems for the identification of irradiated egg, pork and chicken was developed. Eggs were irradiated in their shells to 0.5{approx}7kGy. Pork was irradiated to 0.5{approx}3kGy and chicken irradiated to 0.5kGy{approx}5kGy. The most sensitive proteins to irradiation were screened by SDS-PAGE and purified. Ovalbumin from egg, salt soluble protein(p) from pork, and salt soluble protein(c) from chicken showed the most sensitivity to irradiation. To investigate for a practical use in identifying of irradiated egg, pork and chicken, competitive ELISA was performed. The binding activity of ovalbumin to anti-ovalbumin IgG was reduced in a dose-dependent manner by irradiating up to 7kGy, and considerably lowered after irradiating at 7kGy. The concentration of 50% inhibition of ovalbumin to IgG was increased to 1.5(0.5kGy){approx}3.7(7kGy) times in an dose-dependent relationship. The binding activity of salt soluble ...

2002-04-01

414

Unified semi-microscopic description of low-energy proton and. alpha. -particle scattering by nuclei  

Energy Technology Data Exchange (ETDEWEB)

We develop the formalism of a unified semi-microscopic description of low-energy proton and {alpha}-particle interaction with nuclei. We analyze elastic and inelastic proton scattering at the energy 25.05 MeV and {alpha}-particle scattering at the energy 104 MeV by the {sup 90}Zr nucleus. Information is obtained on differences in the deformation of the proton and neutron distributions. We study the energy dependence of the semi-microscopic {alpha}-particle potential including the energy dependence of the potential geometry.'' We analyze the change in angular distributions of elastically scattered {alpha} particles with increase of energy and the contribution to the scattering cross section from nucleon-nucleon correlations.

1989-07-01

415

True and measured outgassing rates of a vacuum chamber with a reversibly adsorbed phase  

Energy Technology Data Exchange (ETDEWEB)

A pump down model for a vacuum chamber with a reversibly adsorbed phase is presented. The outgassing equation which predicts the variation of coverage at the wall surface of a vacuum chamber with time is derived. Then the measured and the true outgassing rates are defined. The theoretical measured outgassing rate shows only a very weak dependence for pumping speed. This prediction is opposite to the experimental result that the measured outgassing rate depends significantly on pumping speed. It is discussed that the experimental measured outgassing rate must be described as the product of the effective pumping speed and the measured pressure in the pumped chamber, in which the measured pressure is equivalent to the equilibrium pressure of the wall surface described by the equilibrium adsorption isotherm as a function of the shifted surface coverage {theta}-{delta}{theta} by a small coverage {delta}{theta} from the coverage of a pumping point ...

2000-03-01

416

The thermochromic properties of La{sub 1-x}Sr{sub x}MnO{sub 3} compounds  

Energy Technology Data Exchange (ETDEWEB)

La{sub 1-x}Sr{sub x}MnO{sub 3} (LSMO) compounds (0.175{<=}x{<=}0.30) were prepared by conventional solid-state reaction method. Temperature dependence of the total hemispherical emittance ({epsilon}{sub H}) of the compounds from 173 to 373 K was measured on a calorimetric emissometer (CE) which was constructed based on the steady-state calorimetric method. The compounds show thermochromic properties and {epsilon}{sub H}'s have low value at low temperature and have high value at high temperature, because the compounds are dominated by metallic phase and insulator phase, respectively. We use the phase separation model to interpret the temperature dependence of {epsilon}{sub H}. (author)

2008-10-15

417

The pressure- and temperature dependence of the electrical resistivity of some amorphous Fe-B alloys  

International Nuclear Information System (INIS)

We report measurements of the electrical resistivity of the amorphous alloys Fe"4"0Ni"4"0P"1"4B"6 (Metglas 2826), Fe"3"2Ni"3"6Cr"1"4Pr"1"2B"6 (Metglas 2826A) Fe"8"0B"2"0 (Metgals 2605) and Fe"7"5B"2"5 as a function of pressure and temperature. The pressure is varied between 0 and 12 GPa, the temperature between 1.2 and 380 K. At low temperatures the pressure dependence yields additional information on the scattering mechanism. (orig.).

418

The kinetics of the tissue distribution of silver nanoparticles of different sizes  

British Library Electronic Table of Contents (United Kingdom)

Blood kinetics and tissue distribution of 20, 80 and 110 nm silver nanoparticles were investigated in rats up to 16 days after intravenous administration once daily for 5 consecutive days. Following both single and repeated injection, silver nanoparticles disappeared rapidly from the blood and distributed to all organs evaluated (liver, lungs, spleen, brain, heart, kidneys and testes) regardless of size. The 20 nm particles distributed mainly to liver, followed by kidneys and spleen, whereas the larger particles distributed mainly to spleen followed by liver and lung. In the other organs evaluated, no major differences between the sizes were observed. Size-dependent tissue distribution suggests size-dependent toxicity and health risks. Repeated administration resulted in accumulation in li...

2010-01-01

419

The inertial dynamics of thin film flow of non-Newtonian fluids  

CERN Document Server

Consider the flow of a thin layer of non-Newtonian fluid over a solid surface. I model the case of a viscosity that depends nonlinearly on the shear-rate; power law fluids are an important example, but the analysis here is for general nonlinear dependence. The modelling allows for large changes in film thickness provided the changes occur over a large enough lateral length scale. Modifying the surface boundary condition for tangential stress forms an accessible base for the analysis where flow with constant shear is a neutral critical mode, in addition to a mode representing conservation of fluid. Perturbatively removing the modification then constructs a model for the coupled dynamics of the fluid depth and the lateral momentum. For example, the results model the dynamics of gravity currents of non-Newtonian fluids even when the flow is not very slow.

2007-01-01

420

The ground state well depth position R {sub m} of Van der Waals molecules and the spectral line shapes  

Energy Technology Data Exchange (ETDEWEB)

As the ground state potential curve is strongly related to spectral line shapes, the minumum position of the ground state potential is obtained from the experiemental absorption profile k({delta}{nu}, T) at high density of the radiating atoms. The temperature dependence of the absorption processes of Hg and Cd lines 253.65 and 326.1 nm, respectively perturbed by inert gases (Xe, Kr, Ar and Ne) had been carefully studied over a wide spectral range. Using the point of the maximum temperature dependence {delta}{nu} {sub m} in each case, we are able to calculate the position of the ground state potential R {sub m} using a simple formula.

2006-09-15

421

The energy dependence of L_#alpha#/L_l X-ray intensity ratio produced by heavy-ion bombardment  

International Nuclear Information System (INIS)

The energy dependence of the Yb and Au L_#alpha#/L_l X-ray intensity ratio, produced by 0.5 - 3.0 MeV/u Li, Be, C, N, F, and Si ion bombardment (Malhi and Gray, Phys. Rev. A 44, 7199, (1991)), measured at 90"0 relative to the beam axis, has been explained. While for light ion impact the behaviour of the alignment parameter as a function of impact velocity is dominant, for the impact of heavier ions the multiple ionization effects become important. Using Larkins' prescription in the last case, calculations have been performed, which agree well with the data over the whole energy range investigated. (Author).

1993-01-01

422

The chain mechanism in catalytic cracking. The chain mechanism in catalytic cracking  

Energy Technology Data Exchange (ETDEWEB)

The cracking of 2-methylpentane on USHY at 300, 400, 450, and 500[degrees]C is interpreted in detail in terms of a chain mechanism. The kinetic equation developed from this mechanism fits the experimental data very well. The contribution of chain processes to the overall rate of conversion depends on the kinetic chain length, which in turn depends on the surface coverage by carbenium ions and their reactivities. Kinetic parameters were obtained at all four temperatures. A detailed examination of the kinetics shows that chain processes are more important at low reaction temperatures, whereas protolytic cracking dominates at higher temperatures. The parameters also show that both competitive inhibition by products and the rate of catalyst decay increase with increasing reaction temperature. Furthermore, they show that carbenium ions formed on Broensted sites are more stable than carbonium ions. 39 refs., 12 figs., 5 tabs.

1993-03-01

423

Temperature-dependent characteristics and single-mode performance of AlGaInP-based 670--690-nm vertical-cavity surface-emitting lasers  

Science.gov (United States)

The authors report on temperature dependent characteristics and single mode performance of one-wave cavity, planar implanted, AlGaInP-based vertical-cavity surface emitting lasers. By optimizing the overlap between the gain peak and the cavity mode of the structure, they demonstrate record device performance, including 8.2 mW maximum output power and 11% power conversion efficiency for multimode operation and 1.9 mW and 9.6% power conversion efficiency for single mode operation at 687 nm. Improved performance at elevated temperatures is also achieved, with 1.5 mW output power demonstrated at 50 C from a 15-{micro}m-diameter device.

1995-07-01

424

Temperature dependence of threshold current of injection lasers for short pulse excitation  

Energy Technology Data Exchange (ETDEWEB)

We report measurements of the temperature dependence of the threshold current of GaAs, 1.3-..mu..m InGaAsP, and 1.5-..mu..m InGaAsP double heterostructure lasers using short electrical pulses. T/sub 0/approx.200 K is observed for all the lasers. These high T/sub 0/ values show that the carrier density at threshold does not increase rapidly with increasing temperature in any of the lasers studied and thus the observed low cw T/sub 0/ of InGaAsP lasers is primarily due to a decrease of the carrier lifetime at threshold with increasing temperature.

1984-05-15

425

Temperature Dependent Constitutive Modeling for Magnesium Alloy Sheet  

International Nuclear Information System (INIS)

Magnesium alloys have been increasingly used in automotive and electronic industries because of their excellent strength to weight ratio and EMI shielding properties. However, magnesium alloys have low formability at room temperature due to their unique mechanical behavior (twinning and untwining), prompting for forming at an elevated temperature. In this study, a temperature dependent constitutive model for magnesium alloy (AZ31B) sheet is developed. A hardening law based on non linear kinematic hardening model is used to consider Bauschinger effect properly. Material parameters are determined from a series of uni-axial cyclic experiments (T-C-T or C-T-C) with the temperature ranging 150-250 deg. C. The influence of temperature on the constitutive equation is introduced by the material parameters assumed to be functions of temperature. Fitting process of the assumed model to measured data is presented and the results are compared.

2010-06-15

426

Surface segregation and radiation hardening of 16Cr12MoWSiVNbB steel after irradiation with Ni++ and He+ ions  

British Library Electronic Table of Contents (United Kingdom)

Irradiation of EP-823 (16Cr12MoWsiVNbB) ferritic-martensitic steel with 7-MeV Ni++ ions and with 30- and 70-keV He+ ions at a temperature of 500?C was followed by an increase in the microhardness, which was due to both radiation point defects and changes in the phase composition and the dislocation structure of the steel. It was found that the dependence of the largest relative increase in the microhardness on the concentration of radiation-induced point defects in the near-surface region of the steel under irradiation with different ions correlated with an analogous dependence of the surface segregation of silicon and chromium.

2011-01-01

427

Subjective effects to cannabis are associated with use, abuse and dependence after adjusting for genetic and environmental influences  

British Library Electronic Table of Contents (United Kingdom)

Background Previous reports in adults have suggested that the effects experienced after cannabis use can be described in terms of positive and negative subtypes that are heritable and are associated with abuse and dependence. This study extends existing research by inclusion of adolescents and young adults in an offspring of twins design which makes it possible to take into account genetic and environmental risks for substance use disorder. Methods Data were collected from 725 twin members of the Vietnam Era Twin Registry, 839 of their 12-32 year old biological offspring and 427 mothers. Offspring who had ever used cannabis (n=464) were asked the degree to which they typically experienced 13 subjective effects shortly after using cannabis. Latent class analysis (LCA) was used to derive sub...

2009-01-01

428

Studies on thermodynamic properties of III-V compounds by first-principles response-function calculation  

International Nuclear Information System (INIS)

The temperature dependences of the Grueneisen parameter, heat capacity, bulk modulus and linear thermal expansion coefficient of sixteen III-V zincblende compounds are studied by first-principles response-function calculations. The fundamental relationships among these physical parameters are explored. Negative thermal expansions at lower temperature are found in most of these III-V phases except for the nitrides and boron compounds. By analyzing the cell-volume dependences of the phonon spectrum, it is found that the phases with a negative thermal expansion show a significant acoustic phonon weakening at the X-point in their phonon dispersion, while slight weakening is only seen around the L-point for those boron phases. There is no sign of phonon weakening in the nitrides. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

2009-07-01

429

Spectroscopy and photophysics of mono methyl-substituted alloxazines  

Energy Technology Data Exchange (ETDEWEB)

Singlet-singlet and triplet-triplet absorption spectra of a series of methyl-alloxazines were calculated using the time-dependent density-functional theory approach and compared to experimental results. The B3LYP functional provides good correlation between experimental and theoretical results, given that solvent effects are disregarded in the present calculations. Substituent and solvent dependences of the lowest, closely spaced, n,{pi}* and {pi},{pi}* excited state energies are discussed, their order being of consequence in determining the non-radiative decay rates and thus emission quantum yields and lifetimes. The high quantum yields of singlet oxygen formation indicate that the triplet state is formed by efficient intersystem crossing from the first singlet excited state.

2004-05-31

430

Spatial distribution of IGC-30 Ge-detector's efficiency  

International Nuclear Information System (INIS)

The dependence of the efficiency of a coaxial IGC-30 Ge detector on the direction of gamma quanta entry, their energy and the distance from the source is examined. A set of point sources QCR-2 (Amersham, UK) has been used which is arranged consecutively in two perpendicular planes passing through the detector axis, at a distance of 0.1 - 1.3 m (pace 0.1) from its geometric centre for 16 different angles in every plane. Dependence curves of the efficiency on the angle of gamma-quanta hits are obtained for energies 60, 81, 122, 356, 662, 834, 1173 and 1332 keV. Changes in efficiency connected with spatial dividing ability are found out. Using the least squares' method the expected spatial distribution of efficiency is examined with a level of authenticity P > 0.9. The possible causes for the efficiency change and its possible effect on the measurements' precision are discussed. (author).

1993-12-02

431

Simulation study on retention and reflection from tungsten carbide under high fluence of helium ions  

Energy Technology Data Exchange (ETDEWEB)

We have studied, by a Monte Carlo simulation code ACAT-DIFFUSE, the fluence-dependence of the amount of retained helium atoms in tungsten carbide at room temperature under helium ion bombardment. The retention behavior may be understood qualitatively in terms of irradiation-dependent diffusion coefficient assumed and range. The emission processes from tungsten carbide under helium ion irradiation derived were compared with each other. We have discussed the retention curves for incident energy of 5 keV at incident angles of 0deg and 80deg and of 500 eV at 0deg. The energy spectra of helium atoms reflected from tungsten carbide for incident energy of 500 eV at 0deg and 80deg were compared with those from graphite and tungsten. (author)

2000-08-01

432

Secondary ions from condensed gas solids by singly and multiply charged ion impacts  

International Nuclear Information System (INIS)

Ion desorption from a condensed gas solid Ne impacted by singly- and multiply-charged Ar"q"+ ions (q = 1-7) has been investigated. Various secondary ions such as cluster ions, Ne"+_n (n = 2-20) as well as atomic ions are observed. Mass spectral patterns, thickness dependence of the yields, and kinetic energy distributions of the desorbed Ne"+_n (n = 1,2) depend strongly on the projectile charge state. These results indicate that the dissipation of the projectile potential energy on the surface leads to the desorption of the monomer and small cluster ions by a Coulomb repulsion between adjacent target ions.

2009-11-01

433

Resveratrol causes COX-2- and p53-dependent apoptosis in head and neck squamous cell cancer cells  

British Library Electronic Table of Contents (United Kingdom)

Cyclooxygenase-2 (COX-2) content is increased in many types of tumor cells. We have investigated the mechanism by which resveratrol, a stilbene that is pro-apoptotic in many tumor cell lines, causes apoptosis in human head and neck squamous cell carcinoma UMSCC-22B cells by a mechanism involving cellular COX-2. UMSCC-22B cells treated with resveratrol for 24 h, with or without selected inhibitors, were examined: (1) for the presence of nuclear activated ERK1/2, p53 and COX-2, (2) for evidence of apoptosis, and (3) by chromatin immunoprecipitation to demonstrate p53 binding to the p21 promoter. Stilbene-induced apoptosis was concentration-dependent, and associated with ERK1/2 activation, serine-15 p53 phosphorylation and nuclear accumulation of these proteins. These effects were blocked by ...

2008-01-01

434

Resistivity, Hall effect, and magnetic susceptibility of UPd_2Si_2  

International Nuclear Information System (INIS)

The electrical resistivity, Hall effect, and magnetic susceptibility of single-crystal UPd_2Si_2 have been studied between 4.2 and 300 K. A large anisotropy was observed in both the magnetic and transport properties. There is a quadratic temperature dependence of the resistivity for a range of temperatures between 4.2 and 80 K. At higher temperatures, the resistivity indicates a Kondo-type behavior. The behavior of these quantities is accounted for by the magnetic phase transitions at 108 and 136 K reported from neutron-scattering studies. At high temperatures, the magnetic susceptibility of UPd_2Si_2 is Curie-Wiess-like along the c axis. The temperature dependence of the Hall coefficient above 108 K is accounted for by a theoretical model invoking skew scattering of conduction electrons by localized magnetic moments.

435

Resistivity, Hall effect, and magnetic susceptibility of UPd[sub 2]Si[sub 2  

Energy Technology Data Exchange (ETDEWEB)

The electrical resistivity, Hall effect, and magnetic susceptibility of single-crystal UPd[sub 2]Si[sub 2] have been studied between 4.2 and 300 K. A large anisotropy was observed in both the magnetic and transport properties. There is a quadratic temperature dependence of the resistivity for a range of temperatures between 4.2 and 80 K. At higher temperatures, the resistivity indicates a Kondo-type behavior. The behavior of these quantities is accounted for by the magnetic phase transitions at 108 and 136 K reported from neutron-scattering studies. At high temperatures, the magnetic susceptibility of UPd[sub 2]Si[sub 2] is Curie-Wiess-like along the [ital c] axis. The temperature dependence of the Hall coefficient above 108 K is accounted for by a theoretical model invoking skew scattering of conduction electrons by localized magnetic moments.

1993-12-15

436

Reduction of statistic error in Mihalczo subcriticality measurement  

Energy Technology Data Exchange (ETDEWEB)

The theoretical formula for the statistical error estimation in Mihalczo method was derived, and the dependence of the error were investigated on the facility to be measured and on the parameter in the data analysis. The formula was derived based on the reactor noise theory and the error theory for the frequency analysis, and found that the error depends on such parameters as the prompt neutron decay constant, detector efficiencies, and the frequency bandwidth. Statistical errors estimated with the formula was compared with experimental values and verified to be reasonable. Through parameter surveys, it is found that there is an optimum combination of the parameters to reduce the magnitude of the errors. In the experiment performed in DCA subcriticality measurement facility, it is estimated experimentally that the measurement requires 20 minutes to obtain the statistic error of 1% for the keff 0.9. According to the error theory, this might be ...

1998-08-01

437

Reciprocal and coincident patchiness of multiple resources differentially affect benefits of clonal integration in two perennial plants  

British Library Electronic Table of Contents (United Kingdom)

Summary 1.-The modules of plants experience different levels of resources, and clonal plants can integrate resource heterogeneity. However, no studies have tested whether the benefits of clonal integration depend on patterns of heterogeneity in multiple resources, like high levels of above-ground and below-ground resources in the same patches (-coincident patchiness-) or different patches (-reciprocal patchiness-). 2.-We hypothesized that the benefits of clonal integration can vary depending on whether patchiness is reciprocal or coincident, and that clonal species experience greater benefits from integration when qualitative patterns of resource heterogeneity are more like those likely to occur in their habitats. To test these hypotheses, we grew pairs of connected ramets of Cynodon dacty...

2011-01-01

438

Radius of thawing around an injection well and time of complete freezeback  

Science.gov (United States)

An approximate method of calculating the radius of thawing around an injection well is presented. The method is based on the assumption that for a cylindrical system the position of the phase interface in the Stefan problem can be approximated through two functions: one function determines the position of the melting-temperature isotherm in the problem without phase transitions and the second function does not depend on time. The adjusted heating time concept was used to describe the first function. The second function is a known analytical relationship and is expressed in terms of ice content, thermal properties of thawed/frozen formations, formation temperature and the temperature of the injected fluid. Simple approximate formulae are suggested to estimate the duration of the freezeback period. To verify the proposed formulae, the results of numerical solutions were used. An example which shows that the duration of the 'safety period' (free from freezing of water ...

2006-06-01

439

Quick. How much material in that pile  

Energy Technology Data Exchange (ETDEWEB)

Presented are nomographs for calculating volume of bulk materials (e.g. coal, ores, sand, limestone) in conical or oblong piles formed by means of throwers and other mechanical transporting devices. The author explains that when a thrower is stationary, the pile formed resembles a cone and its projection on the ground is roughly circular. If thrower is moving, in general along a straight path, the final shape is more oblong, resulting from overlapping of separately formed cones. Slope of piles depends on the angle of repose which material makes with the horizontal when piled. This angle depends on such factors as internal friction of material stored, the throwing impact, fineness of grains, and moisture content. Volume is determined from the angle of repose and geometrical data on the area occupied by the pile.

1982-10-01

440

Pressure-dependent photoluminescence study of ZnO nanowires  

Energy Technology Data Exchange (ETDEWEB)

The pressure dependence of the photoluminescence (PL) transition associated with the fundamental band gap of ZnO nanowires has been studied at pressures up to 15 GPa. ZnO nanowires are found to have a higher structural phase transition pressure around 12 GPa as compared to 9.0 GPa for bulk ZnO. The pressure-induced energy shift of the near band-edge luminescence emission yields a linear pressure coefficient of 29.6 meV/GPa with a small sublinear term of -0.43 meV/GPa{sup 2}. An effective hydrostatic deformation potential -3.97 eV for the direct band gap of the ZnO nanowires is derived from the result.

2004-09-13

441

Pineal and photoperiodic influences on fat deposition, pelage, and testicular activity in male meadow voles.  

Science.gov (United States)

Pinealectomy completely prevented gonadal regression as well as reduction in body weight and white adipose tissue content of the gonadal and retroperitoneal fat deposits in male meadow voles transferred from long to short day lengths. Pineal influences on pelage characteristics depended on which parameter was assessed. For instance, the increase in guard hair length observed in short-day control voles was blocked by pinealectomy; however, a similar increase in underhair length was unaffected by removal of the pineal gland. Photoperiod-dependent changes in fat deposition, testicular activity, and guard hair length presumably rely on altered pineal secretory activity to transduce the effects of day length on the neuroendocrine axis; however, mechanisms independent of pineal activity may be capable of mediating photoperiodic control of underhair growth. PMID:2979644

1988-01-01

442

Phenomenology of the #LAMBDA#/#SIGMA#production ratio in pp collisions  

International Nuclear Information System (INIS)

We show that the recently measured asymmetry in helicity-angle spectra of the #LAMBDA#-hyperons, produced in the reaction pp#->#K"+#LAMBDA#p reaction, and the energy dependence of the total pp#->#K"+#LAMBDA#p cross-section can be explained consistently by the same #LAMBDA#p final-state interaction. Assuming that there is no final-state interaction in the #SIGMA#"0 p channel, as suggested by the available data for the reaction pp#->#K"+#SIGMA#"0p, we can also reproduce the energy dependence of the #LAMBDA#/#SIGMA#"0 production ratio and, in particular, the rather large ratio observed near the reaction thresholds. The nominal ratio of the #LAMBDA# and #SIGMA#"0 production amplitudes squared, i.e. when disregarding the final-state interaction, turns out to be about 3, which is in line with hyperon production data from proton and nuclear targets available at high energies. (orig.)

2006-09-01

443

Phase composition of the VT22-alloy and its cyclic strength  

International Nuclear Information System (INIS)

In connection with the different cyclical strengths of the two-phase (#alpha# + #beta#) titanium alloy in the case of the acicular and rounded formations of the #alpha#-phase, we have studied, employing the X-ray diffraction method, the phase composition of the alloy and the influence of heat treatment upon it. Using the method of electronic fractography, we examined the fractures in samples destroyed by the asymmetric twisting, in order to find out why the durability of the alloy is dependent upon the #alpha# - phase structure. It has been found that in the BT22 alloy, the decay the #beta#-phase may proceed in two ways; either with the formation of the martensite #alpha#'-phase of the acicular shape or with the separation of the non-martensite round-shaped #alpha#-phase. The character of the phase transformations #beta# - #alpha# or #beta#-#alpha#' is, to a considerable extent, the conseguence of the prehystory of the alloy and is dependent ...

444

Permeation barrier properties of thin oxide films on flexible polymer substrates  

Energy Technology Data Exchange (ETDEWEB)

Solar cells and organic electronic devices require an encapsulation to ensure sufficient lifetime. Key parameters of the encapsulation are permeation barrier, UV stability, temperature stability, optical transmission spectra and mechanical stability. The requirements depend very much on the specific application. Many work groups suggest multilayer stacks to meet the permeation requirements. In this paper the permeation barrier properties of the different constituents of such a multilayer stack are characterized. Different layer materials are compared regarding their water vapour and oxygen permeability as well as the influence of process parameters is examined. Finally temperature dependent permeation measurements are used to characterize the permeation mechanisms in the different constituents of the multilayer barrier.

2009-03-31

445

Performance of a Bragg curve detector for heavy ion identification  

Energy Technology Data Exchange (ETDEWEB)

By using Bragg curve spectroscopy, one can measure atomic number and energy of high energy heavy ions stopping in a gas-filled ionization chamber with longitudinal electric field. In this paper, we report on the results obtained with an isobutane filled detector. An energy resolution of 0.8% fwhm and a Z resolution of 2.7% fwhm were achieved for elastically scattered 300 MeV /sup 40/Ar ions. We study the Bragg peak amplitude dependence on the energy of the incoming ions, a dependence presumably due to the Frisch grid screening inefficiency. The corrected Bragg peak spectrum of inelastically scattered 300 MeV /sup 40/Ar ions exhibits a satisfactory Z separation around Z = 18.

1982-12-15

446

Performance of a Bragg curve detector for heavy ion identification  

International Nuclear Information System (INIS)

By using Bragg curve spectroscopy, one can measure atomic number and energy of high energy heavy ions stopping in a gas-filled ionization chamber with longitudinal electric field. In this paper, we report on the results obtained with an isobutane filled detector. An energy resolution of 0.8% fwhm and a Z resolution of 2.7% fwhm were achieved for elastically scattered 300 MeV "4"0Ar ions. We study the Bragg peak amplitude dependence on the energy of the incoming ions, a dependence presumably due to the Frisch grid screening inefficiency. The corrected Bragg peak spectrum of inelastically scattered 300 MeV "4"0Ar ions exhibits a satisfactory Z separation around Z = 18. (orig.).

447

Patterns of proliferation and differentiation of irradiated haemopoietic stem cells cultured on normal 'stromal' cell colonies in vitro  

Energy Technology Data Exchange (ETDEWEB)

Experiments were designed to elucidate whether or not the irradiated bone marrow cells receive any stimulation for the self-replication and differentiation from normal 'stromal' cell colonies in the bone marrow cell culture in vitro. When irradiated or unirradiated bone marrow cells were overlaid on the normal adherent cell colonies, the proliferation of haemopoietic stem cells was supported, the degree of the stimulation depending on the starting cellular concentration. There was, however, no significant changes in the concentration of either CFUs or CFUc regardless of the dose of irradiation on the bone marrow cells overlaid. This was a great contrast to the dose-dependent decrease of CFUs or CFUc within the culture in which both the stem cells and stromal cells were simultaneously irradiated. These results suggest that the balance of self-replication and differentiation of the haemopoietic stem cells is affected only when ...

1981-09-01

448

Particulate composites in the TiC-TiYTZP system  

International Nuclear Information System (INIS)

Twelve powders of TiO_2-Y_2O_3-ZrO_2 solid solution of the methodically changed composition were prepared by a coprecipitation-calcination technique. After mixing with phenol-formaldehyde resin, the powders were calcinated for 2 hours at 1200"oC in vacuum. The resultant composite powders contained TiC and non-reacted carbon. Green compacts were sintered in vacuum at 1500"oC for 2 hours. A temperature increase was stopped at 1200"oC to react remains of carbon. There were two carbides in the composites TiC and ZrC. TiC non-stoichiometry depended on carbon content in the system. Phase composition of the depended on of titania and yttria in zirconia solid solution. The majority of the samples showed two tetragonal zirconia phases differing in lattice parameter and tetragonality. (author)

2004-09-12

449

On the suitability of alternate fuels for dual fuel engine operation  

Energy Technology Data Exchange (ETDEWEB)

A compression ignition engine was operated on dual fuel principle inducting two commercial fuels and four pure hydrocarbon fuels in turn through intake manifold along with air and injecting diesel fuel to initiate the combustion in the conventional manner. The engine was operated at different loads and at each load the quantity of inducted fuel was increased gradually till knocking set in. The engine performance and exhaust pollutant emissions were recorded at different operating conditions. It was observed that the extent of induction and the effect on the performance depend on the properties of the inducted fuel such as volatility, self ignition temperature and oxidation characteristics. The energy release during the cycle was also observed to shift depending on the properties of inducted fuel. With the dual fuel operation, the thermal efficiency at part loads was observed to be less compared to neat diesel operation. The thermal efficiency ...

1980-12-01

450

Nuclei with protrusions - tailed nuclei - and radiation cytogenetic markers in X-irradiated lymphocytes in vitro  

International Nuclear Information System (INIS)

The results of an investigation into tailed nuclei (TN) and features of dose dependence on frequency of the binuclear cells with TN in human lymphocyte cultures by cytogenetic block method upon X-ray radiation dose are presented. The frequencies of metaphases with dicentric and ring chromosomes are investigated concurrent with TN formed upon completion of first postradiation mitosis. Frequency of the appearance of binuclear cells with nuclei having outgrowth into the cytoplasmic space and arises after first mitosis in human lymphocyte culture is linear-square dependent on the X-irradiation at doses from 0.0 to 4.0 Gy. Positive correlation between frequency of cells with tailed nuclei and frequency of metaphases of first mitosis having dicentric and rings was established. Apparently, formation such TN is connected with dicentric and rings

451

Nuclear magnetic resonance study of La_3X compounds and related phases  

International Nuclear Information System (INIS)

Normal state nuclear magnetic resonance studies of the La_3In, La_3Tl compounds have been made in order to investigate the origin of the large temperature-dependent magnetic susceptibility. It is possible to analyse the different contributions to the susceptibility using Knight-shift and relaxation time T_1 measurements of In"1"1"5 and Tl"2"0"5 nuclei. The exchange enhancement of the spin-susceptibility chisub(pd) is of the same order as that found in A-15 compounds and the strong temperature-dependence of chi(T) is attributed to the presence of a peak in the electronic density of states near the Fermi level. The variation of the Knight-shift in the ternary alloys La_3Xsub(1-y)Xsub(y)sup(') is analogous to that observed in the corresponding La_3X phases, on the other hand the Knight-shift in the carbides La_3XC is temperature independent. (author).

452

Nuclear fission with mean-field instantons  

CERN Document Server

We present a description of nuclear spontaneous fission, and generally of quantum tunneling, in terms of instantons - periodic imaginary-time solutions to time-dependent mean-field equations - that allows for a comparison with more familiar and used generator coordinate (GCM) and adiabatic time-dependent Hartree-Fock (ATDHF) methods. It is shown that the action functional whose value for the instanton is the quasiclassical estimate of the decay exponent fulfils the minimum principle when additional constraints are imposed on trial fission paths. In analogy with mechanics, these are conditions of energy conservation and the velocity-momentum relations. In the adiabatic limit the instanton method reduces to the time-odd ATDHF equation, with collective mass including the time-odd Thouless-Valatin term, while the GCM mass completely ignores velocity-momentum relations. This implies that GCM inertia generally overestimates instanton-related decay ...

2007-01-01

453

Neutrino Oscillations: from Standard and Non-standard Viewpoints  

CERN Document Server

In the standard model of neutrino oscillations, the neutrino flavor states are mixtures of mass-eigenstates, and the phenomena are well described by the neutrino mixing matrix, i.e., the PMNS matrix. I review the recent progress on parametrization of the neutrino mixing matrix. Besides that I also discuss on the possibility to describe the neutrino oscillations by a non-standard model in which the neutrino mixing is caused by the Lorentz violation (LV) contribution in the effective field theory for LV. We assume that neutrinos are massless and that neutrino flavor states are mixing states of energy eigenstates. In our calculation the neutrino mixing parts depend on LV parameters and neutrino energy. The oscillation amplitude varies with the neutrino energy, thus neutrino experiments with energy dependence may test and constrain the Lorentz violation scenario for neutrino oscillation.

2011-01-01

454

Moessbauer investigation of the magnetic anisotropy and electronic structure of a metallic glass  

International Nuclear Information System (INIS)

The temperature dependence of the average magnetization direction in an Fe_8_0B_2_0 glassy alloy (METGLAS 2605) is investigated by Moessbauer spectroscopy. Moessbauer spectra were recorded between 77 K and 363 K using a conventional constant-acceleration Moessbauer spectrometer with 10 mCi "5"7Co in Pd source. The direction of the easy magnetization is found to be strongly terperature dependent and the out-of-plane component turned to be unusually large. Comparing the magnetic moments some similarities between the electronic structure of the glassy alloy and the Fe_2B and FeB intermetallic compounds are established and discussed. (Sz.N.Z.).

455

Magnetic susceptibility and electrical properties of Ln/sub 2/3+x/TiO/sub 3+y/ (Ln = Ce, Nd) at 77-450/sup 0/K  

Energy Technology Data Exchange (ETDEWEB)

The magnetic susceptibility and electrical resistivity in cerium and neodymium titanate bronzes in Ln/sub 2/3+x/TiO/sub 3+y/ of the perovskite structure were investigated in the temperature range 77-450/sup 0/K. The deviation of the 1/x = f(T) dependence from the Curie-Weiss law, found for a majority of the compositions, was interpreted from the crystal-field effect based on the state of the Ce/sup 3 +/ and Nd/sup 3 +/ cations. For a number of the phases, a transition from metallic conductivity at high temperatures to semiconducting conductivity was detected at temperatures below 200-250/sup 0/K, which agrees well with the conclusion about the temperature dependence of x, related to the subsystem of Ti/sup 3 +/ cations.

1987-01-01

456

Light emission from hydrogen-copper interaction at grazing incidence  

Energy Technology Data Exchange (ETDEWEB)

The optical emission of excited H reflected from clean Cu(110) after impingement of H/sup +/ and H/sub 2//sup +/ in the energy range of 250 eV to 20 keV per nucleon at 70/sup 0/ angle of incidence to the surface normal was measured. For incident 10 keV H/sub 2//sup +/, the highest excited hydrogen state detected was the n=10 level. The Hsub(..cap alpha..) yield was found to be fluence and energy dependent. This effect is attributed either to fast sputtered hydrogen, surface roughness or to an increase with hydrogen concentration in electron states of p-like symmetry near the Fermi level of copper. The Hsub(..cap alpha..) yield per reflected nucleon shows approximately an exponential dependence on both projectile energy per nucleon and scattered particle reciprocal velocity perpendicular to the surface.

1984-03-01

457

Light emission from hydrogen-copper interaction at grazing incidence  

International Nuclear Information System (INIS)

The optical emission of excited H reflected from clean Cu(110) after impingement of H"+ and H_2"+ in the energy range of 250 eV to 20 keV per nucleon at 70"0 angle of incidence to the surface normal was measured. For incident 10 keV H_2"+, the highest excited hydrogen state detected was the n=10 level. The Hsub(#alpha#) yield was found to be fluence and energy dependent. This effect is attributed either to fast sputtered hydrogen, surface roughness or to an increase with hydrogen concentration in electron states of p-like symmetry near the Fermi level of copper. The Hsub(#alpha#) yield per reflected nucleon shows approximately an exponential dependence on both projectile energy per nucleon and scattered particle reciprocal velocity perpendicular to the surface. (orig.).

1983-07-01

458

Kriging analysis of soil properties  

British Library Electronic Table of Contents (United Kingdom)

Background, aim, and scope Soil as a landscape body contains wide ranges of physical, chemical, morphological, and mineralogical properties, both laterally and vertically. Soils with similar properties and environments are expected to behave similarly. A statement on land use potential will depend in part on the precision and accuracy of the statements that can be made about the soils. This information has some practical applications in optimizing land management and productivity improvement. The spatial patterns and dependence of some selected physicochemical properties of brackish marsh and surrounding soils were investigated using a 2-D kriging analysis in conjunction with a geostatistical (GS+, Michigan) model. Materials and methods Composite (four subsamples) surface samples (0?20?cm)...

2008-01-01

459

K/sub. beta. //K/sub. cap alpha. / X-ray intensity ratio following K-electron capture and radioisotope excitation  

Energy Technology Data Exchange (ETDEWEB)

The K/sub ..beta..//K/sub ..cap alpha../ X-ray intensity ratios are measured for Mn and Fe and for six other elements with Z lying in the range 49 less than or equal to Z less than or equal to 82 following electron capture decay and photon excitation using /sup 241/Am and /sup 57/Co sources. High-resolution Si(Li) and HpGe detector systems were used in the experiments. The dependence of K/sub ..beta..//K/sub ..cap alpha../ values on the mode of excitation in the case of Mn and Fe is attributed to chemical effects, while no such dependence is found for the high-Z elements.

1987-01-01

460

Irradiation of Langmuir-Blodgett multilayer preparations of phospholipids and a fatty acid. Pt. 1; Effect of UV radiation  

Energy Technology Data Exchange (ETDEWEB)

Langmuir-Blodgett (LB) preparations containing stacked monolayers of phospholipids or stearic acid were irradiated with UV light and the electric conductance perpendicular to the planes of the monolayers was measured. There was no observable change of conductance when LB preparations of stearic acid were irradiated. For LB preparations of phospholipids, a rise of conductance, dependent on dose rate, was observed, reaching an equilibrium level after a few hours. After irradiation the conductance fell with a temperature-dependent time constant, and eventually reached a final level a little above the initial value. A three-state model is proposed for the LB phospholipid preparations. This suggests that the absorption of one photon raises a molecule from the ground to an excited state; and the absorption of a second photon carries it into a damaged but repairable or metastable state. (author).

1992-12-01

461

Ionizing radiation effect on sealant properties  

International Nuclear Information System (INIS)

Presented are the investigation results of electrophysical and physico-mechanical properties of KLF-20, Viksint U-4-21, Viksint KT-73, UF-7-21, KG-184, KL-4, KL-16SE-305, VIAT-1 and PPK-21 sealants, irradiated with sources of continuous and pulse #gamma#-radiation, as well as pulse #gamma#-neutron radiation. It is shown that electrophysical and physico-mechanical properties of sealants after irradiation by continuous #gamma#-radiation up to 10"6 doses and pulse gamma-neutron radiation with neutron fluence of 10"1"3 neutron/cm"2 and #gamma#-radiation dose of 10"4R do not practically change. Electric conductivity and tangent of the angle of dielectric losses increase in the process of irradiation. Electric conductivity depends on irradiation type, is proportional to dose rate and does not depend on temperature and pulse duration.

462

Identification of actively filling sucrose sinks. [Solanum tuberosum; Phaseolus lunatus; Manihot esculenta; Liquidambar styraciflua L. ; Carya illinoinensis  

Energy Technology Data Exchange (ETDEWEB)

Certain actively filling plant sucrose sinks such as a seed, a tuber, or a root can be identified by measuring the uridine diphosphate and pyrophosphate-dependent metabolism of sucrose. Sucrolysis in both active and quiescent sucrose sinks was tested and sucrose synthase was found to be the predominant sucrose breakdown activity. Sucrolysis via invertases was low and secondary in both types of sinks. Sucrose synthase activity dropped markedly, greater than fivefold, in quiescent sinks. The test are consistent with the hypothesis that the sucrose filling activity, i.e. the sink strength, of these plant sinks can be measured by testing the uridine diphosphate and pyrophosphate-dependent breakdown of sucrose. Measuring the initial reactions of sucrolysis shows much promise for use in agriculture crop and tree improvement research as a biochemical test for sink strength.

1989-04-01

463

Helium/solid powder O-ring leakage correlation experiments using a radiotracer  

Energy Technology Data Exchange (ETDEWEB)

UO/sub 2/ definitely leaked past the O-ring in three of the tests confirming the major results of the previous work. Continuous leakage at these levels may require additional precautions under present regulatory policies. The mechanism and the time and particle size dependence for the leakage are not known, but there is some indication leakage is more likely at low temperatures. It is possible leakage is due to movement of the O-ring during temperature or pressure cycling at the beginning or end of a test. The radiotracer method involves less labor and is much less susceptible to contamination than the previous method. Future work will investigate leakage past lubricated O-rings and time dependence of leakage. 1 reference, 1 table.

1984-01-01

464

Gas sensor arrays (electronic noses) and their combination with trap techniques  

Energy Technology Data Exchange (ETDEWEB)

In the food, chemical and safety industry there is a demand for gas detectors for process control applications, like quality control of food or leakage control in chemical plants. Gas sensor array systems have the potential to be used in this areas, with the advantage of being also affordable systems compared to other systems like gaschromatographs (GC) or infrared detectors (NIR, FTIR). One of the main drawbacks of the gas sensors is their response to non interesting ambient factors like temperature, pressure and humidity. Metal oxide sensors (MOS) have a low ambient temperature and pressure dependency. Some of them (SnO + dopands) have some sensitivity to humidity. In many cases the response of the sensors is often non-linear, which implies a concentration dependant pattern of the samples. (orig.)

2001-07-01

465

Formation of metal-polymer hybrid nanostructures during radiation-induced reduction of metal ions in poly(acrylic acid)-poly(ethylenimine) complexes  

British Library Electronic Table of Contents (United Kingdom)

The formation of nanoparticles during the radiation-induced chemical reduction of silver ions, copper ions, and nickel ions in films based on poly(acrylic acid)-poly(ethylenimine) complexes are studied via electron microscopy. This approach allows preparation of composites containing nanoparticles that are randomly distributed in the polymer matrix and materials with a regular spatial distribution of nanoparticles across the film thickness and in subsurface layers. The structure of metal-polymer hybrid materials is dependent on the irradiation conditions, the type of reduced metal ions, and their initial content in polymer matrices. The ratio between the rate of nucleation and the rate of growth of nanoparticles in the matrices of interpolyelectrolyte complexes depends on the intensity of ...

2011-01-01

466

Extraction of Cs-137 by alcohol-water solvents from plants containing cardiac glycosides  

CERN Document Server

As a result of nuclear power plant accidents, large areas receive radioactive inputs of Cs-137. This cesium accumulates in herbs growing in such territories. The problem is whether the herbs contaminated by radiocesium may be used as a raw material for medicine. The answer depends on the amount of Cs-137 transfered from the contaminated raw material to the medicine. We have presented new results of the transfer of Cs-137 from contaminated Digitalis grandiflora Mill. and Convallaria majalis L. to medicine. We found that the extraction of Cs-137 depends strongly on the hydrophilicity of the solvent. For example 96.5%(vol.) ethyl alcohol extracts less Cs-137 (11.6%) than 40%(vol.) ethyl alcohol or pure water (66.2%). The solubility of the cardiac glycosides is inverse to the solubility of cesium, which may be of use in the technological processes for manufacturing ecologically pure herbal medicine.

2001-01-01

467

Experimental Investigation of Solar Drying for Orange Peels by Forced convection  

International Nuclear Information System (INIS)

Solar drier does not degrade any more the dried products with the manner of the products dried at the natural sun. The drying unit is composed mainly of a solar air collector and an enclosure of drying. The transformation of the solar radiation into heat is done thanks to the solar collector whose effectiveness is increased by the addition of suitable baffles in the mobile air vein. The efficiency of the collector reaches then 80. The hot air on the outlet side of the collector arrives in the enclosure of drying where the heat transfer with the product to be dried is done by convection. The kinetics drying study shows that in addition to the dependence of the temperature and air velocity of drying, the speed of drying also depends on fragmentation on the product to dry, and mainly, of the product surface in contact with the drying air. Thus, the hygrometry is reduced from 76 to 13 pour cent in one day.. The total efficiency of the drier reached ...

2009-01-30

468

Erosion testing of CRC 262; Erosionsprovning av CRC 262  

Energy Technology Data Exchange (ETDEWEB)

Solid particle erosion (SPE) testing was made on Sandvik CRC 262 with different heat treatments and on the steels Type 321 and 15Mo3. The Studsvik Erofuge, a centrifugal erosion tester, was used and the testing was performed in air at room temperature. Alumina and olivine sand particles were used at a particle velocity of 60 m/s and at impingement angles of 60 degrees and 90 degrees. Differences in erosion resistance were obtained for CRC 262 depending on the heat treatment. Olivine sand resulted in lower erosion of CRC 262 than when using alumina. The particle type dependence is low for the other materials, Tp 321 and 15Mo3. CRC 262 has a slightly higher erosion resistance than Tp 321 and 15Mo3 and the differences are most pronounced when using olivine sand

1993-09-01

469

Energy efficient wireless unicast routing alternatives for machine-to-machine networks  

British Library Electronic Table of Contents (United Kingdom)

Machine-to-machine (M2M) communications is a new and rapidly developing technology for large-scale networking of devices without dependence on human interaction. Energy efficiency is one of the important design objectives for machine-to-machine network architectures that often contain multi-hop wireless subnetworks. Constructing energy-efficient routes for sending data through such networks is important not only for the longevity of the nodes which typically depend on battery energy, but also for achieving an environmentally friendly system design overall, which will be imperative as M2M networks scale in number of nodes as projected. The objective of this survey is to provide a comprehensive look into shortest-path based energy-efficient routing alternatives to provide a reference for sys...

2011-01-01

470

Effect of carrier on surface decontamination efficiency  

International Nuclear Information System (INIS)

The dependence was determined of the decontamination factor ratio found in the presence of a carrier and in a carrier-free system on carrier concentration at different concentrations of a complexing agent in a solution. Bearing balls were used as contamination materials while a mixture of "1"5"2Eu and "1"5"4Eu isotopes was used as a contaminant, citric acid in a concentration of 5x10"-"3 to 1x10"-"1 mol/dm"3 as a complexing agent, and Eu, lanthanum and aluminium at a concentration range of 1x10"-"5 to 1x10"-"2 mol/dm"3 as carriers. While no increase in the decontamination factor was found for aluminium, a considerable increase was observed in the isotopic and homologic carriers and the concentration dependence of the carrier reached the maximum. An equation was derived explaining the effect by the isotope exchange between the contaminant and the carrier and by the reaction between the carrier and the complexing agent. (J.F.).

471

Do spatial effects appear at low dilution rate in chemostat?  

British Library Electronic Table of Contents (United Kingdom)

The chemostat theory on two species competition has shown that the dilution rate where transition of dominance occurs - transition-dilution rate - is independent of limiting-nutrient concentration. However, we obtained the experimental data indicating that the transition-dilution rate changed with variations in limiting-ammonium concentrations, using the chemostat mixed-culture of the cyanobacterium Microcystis novacekii and the green alga Scenedesmus quadricauda. The transition-dilution rate was dependent on the concentration of limiting ammonium in the influx culture medium. We tried to simulate the experimental results. Though the dilution rate has been considered independent of nutrient concentration, we introduce the effective dilution rate that depends on nutrient concentration (ammo...

2009-01-01

472

Determining a bisection bandwidth for a multi-node data communications network  

Energy Technology Data Exchange (ETDEWEB)

Methods, systems, and products are disclosed for determining a bisection bandwidth for a multi-node data communications network that include: partitioning nodes in the network into a first sub-network and a second sub-network in dependence upon a topology of the network; sending, by each node in the first sub-network to a destination node in the second sub-network, a first message having a predetermined message size; receiving, by each node in the first sub-network from a source node in the second sub-network, a second message; measuring, by each node in the first sub-network, the elapsed communications time between the sending of the first message and the receiving of the second message; selecting the longest elapsed communications time; and calculating the bisection bandwidth for the network in dependence upon the number of the nodes in the first sub-network, the predetermined message size of the first test message, and the longest elapsed ...

2010-01-26

473

Dependence of ion-induced Pd-silicide formation on nuclear energy deposition density  

Energy Technology Data Exchange (ETDEWEB)

Pd/sub 2/Si formation at the Pd-Si interface induced by irradiation with ions having a wide range of nuclear energy of deposition density has been investigated. It is found that the thickness of the silicide layer formed by irradiation is proportional to the ion fluence for irradiation with ions having low energy-deposition densities, while it is proportional to the square root of the fluence for irradiation with ions having energy-deposition densities. The results indicate that Pd/sub 2/Si formation is reaction limited when the energy-deposition density at the interface is low and is diffusion limited when it is high. The results are compared with the phenomenological theory developed by Horino et al. and it is shown that such a dependence of the limiting processes on the energy depositon density is induced when the diffusion is thermally activated while the reaction at the interface is radiation-enhanced.

1986-05-01

474

Densification of Y_2O_3 by HIP  

International Nuclear Information System (INIS)

Densification of Y_2O_3 by HIP was investigated in the range 1250"0C-1550"0C at a pressure of 150 MPa. Runs were made in metallic capsules with 200 g of powder. The powder under investigation is 99.9% purity, supplied by RHONE-POULENC. The study reveals the importance of residual gases in the HIP technique of powder densification. The density of the final product is in the range 93% to 100% of theoretical density depending on pretreatment (or outgassing) of the powder. Residual gases have been identified. Final products have been characterized by microscopy (grain size, porosity, microhardness). Porosity and grain size depend on pretreatment conditions. In particular a 1200"0C pretreatment results in zero porosity and significant decrease of grain size. 4 tables, 11 figs, 16 refs.

1986-11-10

475

Decreased dendritic spine density and abnormal spine morphology in Fyn knockout mice  

British Library Electronic Table of Contents (United Kingdom)

Fyn is a Src-family tyrosine kinase that affects long term potentiation (LTP), synapse formation, and learning and memory. Fyn is also implicated in dendritic spine formation both in vitro and in vivo. However, whether Fyn's regulation of dendritic spine formation is brain-region specific and age-dependent is unknown. In the present study, we systematically examined whether Fyn altered dendritic spine density and morphology in the cortex and hippocampus and if these effects were age-dependent. We found that Fyn knockout mice trended toward a decrease in dendritic spine density in cortical layers II/III, but not in the hippocampus, at 1month of age. Additionally, Fyn knockout mice had significantly decreased dendritic spine density in both the cortex and hippocampus at 3months and 1year, an...

2011-01-01

476

Crossover of the magnetic levels and adiabatic magnetization of the mesoscopic cluster V15  

British Library Electronic Table of Contents (United Kingdom)

The magnetic three spin-1/2 model for nanometer-scale molecular cluster V15 is analyzed with the emphasis on the origin of the mixing of different spin levels in the resonance fields that is generally important for the problem of single molecular magnets. The zero-field splitting in the ground quadruplet (two Formula Not Shown levels) is shown to depend mainly on the normal component of AS exchange meanwhile the zero-field splitting in the excited Formula Not Shown multiplet is a second order effect with respect to in-plane components of AS exchange. The normal component of the AS exchange is shown to lead to the exact crossing of the magnetic sublevels at the arbitrary direction of the field. The positions of two crossing/anticrossing points in the ground manifold depend mainly on the iso...

2006-01-01

477

Contents of polycyclic aromatic hydrocarbons (PAH) and phenolic substances in Frankfurter-type sausages depending on smoking conditions using glow smoke  

British Library Electronic Table of Contents (United Kingdom)

The contents of polycyclic aromatic hydrocarbons (PAH) and phenolic substances in Frankfurter-type sausages were investigated depending on hot smoking conditions (glow smoke). For the 24 smoking experiments (performed in duplicates) three different smoke densities and ventilator velocities as well as wood chips with five different moisture contents were tested. During the smoking process, concentrations of O"2, CO"2 and CO, humidity and temperature in the smoking chamber as well as smoke generation temperature were determined. The chemical analysis included the contents of the 15+1 EU priority PAH and the phenolic substances guaiacol, 4-methylguaiacol, syringol, eugenol and trans-isoeugenol. The smoking conditions had a significant influence on smoke generation temperature, organoleptic pr...

2012-01-01

478

Asymmetrical mechanical behavior of a precipitation hardened beta titanium alloy  

International Nuclear Information System (INIS)

Precipitation-hardened single crystals of a beta (bcc) Ti--40 at. percent V--1.0 at. percent Si alloy were deformed in compression at 77 and 298"0K. The dependence of the yield stress upon aging time at 843"0K for solution-treated crystals shows two maxima which are caused by silicide precipitates. The orientation dependence of the yield stress and of the active macroscopic slip plane were determined as a function of aging time. The solution-treated as well as aged crystals exhibit an asymmetry of both the yield stress and the plane of slip, the degree of asymmetry being larger at 77 than at 298"0K. The asymmetry of slip and yielding is not affected by the presence of precipitation hardening. Results indicate that the effect of the dislocation core structure on dislocation motion is independent of the presence of precipitates. (auth).

479

Assessment of GABARAP self-association by its diffusion properties  

Energy Technology Data Exchange (ETDEWEB)

Gamma-aminobutyric acid type A receptor-associated protein (GABARAP) belongs to a family of small ubiquitin-like adaptor proteins implicated in intracellular vesicle trafficking and autophagy. We have used diffusion-ordered nuclear magnetic resonance spectroscopy to study the temperature and concentration dependence of the diffusion properties of GABARAP. Our data suggest the presence of distinct conformational states and provide support for self-association of GABARAP molecules. Assuming a monomer-dimer equilibrium, a temperature-dependent dissociation constant could be derived. Based on a temperature series of {sup 1}H{sup 15}N heteronuclear single quantum coherence nuclear magnetic resonance spectra, we propose residues potentially involved in GABARAP self-interaction. The possible biological significance of these observations is discussed with respect to alternative scenarios of oligomerization.

2010-09-15

480

Analysis of effect factors-based stochastic network planning model  

British Library Electronic Table of Contents (United Kingdom)

Looking at all the indeterminate factors as a whole and regarding activity durations as independent random variables, the traditional stochastic network planning models ignore the inevitable relationship and dependence among activity durations when more than one activity is possibly affected by the same indeterminate factors. On this basis of analysis of indeterminate effect factors of durations, the effect factors-based stochastic network planning (EFBSNP) model is proposed, which emphasizes on the effects of not only logistic and organizational relationships, but also the dependent relationships, due to indeterminate factors among activity durations on the project period. By virtue of indeterminate factor analysis the model extracts and describes the quantitatively indeterminate effect f...

2008-01-01

481

All-atom molecular dynamics simulations using orientational constraints from anisotropic NMR samples  

British Library Electronic Table of Contents (United Kingdom)

Orientational constraints obtained from solid state NMR experiments on anisotropic samples are used here in molecular dynamics (MD) simulations for determining the structure and dynamics of several different membrane-bound molecules. The new MD technique is based on the inclusion of orientation dependent pseudo-forces in the COSMOS-NMR force field. These forces drive molecular rotations and re-orientations in the simulation, such that the motional time-averages of the tensorial NMR properties approach the experimentally measured parameters. The orientational-constraint-driven MD simulations are universally applicable to all NMR interaction tensors, such as chemical shifts, dipolar couplings and quadrupolar interactions. The strategy does not depend on the initial choice of coordinates, and...

2007-01-01

482

Aerial dispersal plasticity under different wind velocities in a salt marsh wolf spider  

British Library Electronic Table of Contents (United Kingdom)

Dispersal can be regarded as a process operating both between and within patches of suitable habitat. For uncontrolled dispersal processes, the risk of crossing the borders of the habitat patch and arriving in the unsuitable landscape matrix will increase with decreasing patch area, in particular when the distance between isolated habitat patches is larger than the species' average dispersal capacity. Ballooning dispersal in spiders can be considered as a passive dispersal process, in which dispersed distances depend on the prevalent wind velocity. We executed a reaction norm analysis to analyze how dispersal propensity of the salt marsh wolf spider Pardosa purbeckensis depended on population characteristics (patch size) and the environment (wind velocity). Dispersal propensity was affecte...

2007-01-01

483

A wave effect enabling universal frequency scaling, monostatic passive radar, incoherent aperture synthesis, and general immunity to jamming and interference  

CERN Document Server

A fundamental Doppler-like but asymmetric wave effect that shifts received signals in frequency in proportion to their respective source distances, was recently described as means for a whole new generation of communication technology using angle and distance, potentially replacing TDM, FDM or CDMA, for multiplexing. It is equivalent to wave packet compression by scaling of time at the receiver, converting path-dependent phase into distance-dependent shifts, and can multiply the capacity of physical channels. The effect was hitherto unsuspected in physics, appears to be responsible for both the cosmological acceleration and the Pioneer 10/11 anomaly, and is exhibited in audio data. This paper discusses how it may be exploited for instant, passive ranging of signal sources, for verification, rescue and navigation; incoherent aperture synthesis for smaller, yet more accurate radars; universal immunity to jamming or interference; and precision ...

2008-01-01

484

A phenomenological model for the macroscopic characteristics of irradiated silicon  

International Nuclear Information System (INIS)

The dependence of the carrier concentrations, of the resistivity and of the Hall coefficient of irradiated silicon on the neutron fluences has been investigated, starting from the supposition that the main phenomena induced by irradiation in the semiconductor bulk are shallow-donor removal and deep-centres creation. The free parameters of the model are initial doping of the starting material, the permitted energy level values of the radiation-induced centres in the semiconductor band gap and their introduction rates. The influence of each parameter on the calculated dependences is studied in detail, for three cases: one deep acceptor-like centre, two deep acceptors and one deep acceptor plus one deep donor-like centre. each of the three cases is discussed in correspondence with different experimental results.

485

A microscopic model of electronic field noise heating in ion traps  

CERN Document Server

Motional heating of ions in micro-fabricated traps is a challenge hindering experimental realization of large-scale quantum processing devices. Recently a series of measurements of the heating rates in surface-electrode ion traps characterized their frequency, distance, and temperature dependencies, but our understanding of the microscopic origin of this noise is still vague. In this work we develop a theoretical model for the electric field noise which is associated with a random distribution of adsorbed atoms on the trap electrode surface. By using first principle calculations of the fluctuating dipole moments of the adsorbed atoms we evaluate the distance, frequency and temperature dependence of the resulting electric field fluctuation spectrum.Our theory calculates the noise spectrum beyond the standard scenario of two-level fluctuators, by incorporating all the relevant vibrational states. The $1/f$ noise is shown to commence at roughly ...

2011-01-01

486

A method to study heavy ion reactions using position sensitive and Bragg curve spectroscopy detectors  

Energy Technology Data Exchange (ETDEWEB)

A large area Bragg curve spectroscopy (BCS) detector and a position sensitive parallel grid avalanche counter have been developed to study heavy ion reactions, such as inelastic excitations and few nucleon transfer reactions near the Coulomb barrier. Reasonably good resolutions have been achieved for energy, atomic number and angle. A theoretical investigation on the mass dependence of the Bragg peak signal from the BCS detector, shows that there is a negligible mass dependence related to the geometry of the detector. The mass number of the heavy ions which cannot be obtained by the above method, has been identified by detecting the corresponding characteristic gamma rays from the product nuclei with two large solid angle gamma ray detectors. (orig.)

1993-10-15

487

A method to study heavy ion reactions using position sensitive and Bragg curve spectroscopy detectors  

International Nuclear Information System (INIS)

A large area Bragg curve spectroscopy (BCS) detector and a position sensitive parallel grid avalanche counter have been developed to study heavy ion reactions, such as inelastic excitations and few nucleon transfer reactions near the Coulomb barrier. Reasonably good resolutions have been achieved for energy, atomic number and angle. A theoretical investigation on the mass dependence of the Bragg peak signal from the BCS detector, shows that there is a negligible mass dependence related to the geometry of the detector. The mass number of the heavy ions which cannot be obtained by the above method, has been identified by detecting the corresponding characteristic gamma rays from the product nuclei with two large solid angle gamma ray detectors. (orig.).

488

A concept to optimize quality and cost in thermoplastic composite components applied to the production of helicopter canopies  

British Library Electronic Table of Contents (United Kingdom)

A concept for the optimization of manufacturing processes of composite material components with regard to product's quality and cost is introduced and applied for the case of thermoplastic composite helicopter canopies produced by `Cold' Diaphragm Forming (CDF) process. The proposed methodology relies on the consideration of the processes thermal cycle as decisive for the component's quality and cost. Quality and cost sensitivity analyses were made to derive material dependent Quality Functions (QFs) and process dependent Cost Estimation Relationships (CERs). QFs and CERs are exploited to derive iteratively the optimal thermal cycle. The processes thermal cycle is numerically simulated to allow for its virtual application on the material. To perform the optimization procedure a new softwar...

2009-01-01

489

Theory of bistability in the face-pumped laser with bimolecular recombination  

Science.gov (United States)

Steady-state and transient behavior of the longitudinally pumped semiconductor laser is theoretically investigated by using a rate-equation model with distributed gain and photon density. Conditions necessary for bistable operation are derived. Dependencies of such major switching characteristics as turn-on and turn-off powers, delay, and rise times on laser parameters are examined. Influences of spontaneous radiation, impurities, and Auger recombination are studied. The results offer an explanation for the observed nonlinear behavior of face-pumped lasers.

1987-01-01

490

Statistical mechanics and thermodynamics for tachyons  

International Nuclear Information System (INIS)

Momentum- and speed-dependent Maxwell-Boltzmann equilibrium distributions have been derived for tachyons and compared with the corresponding relativistic distributions. This is followed by a calculation of the mean, most probable and r.m.s. speeds for both the relativistic and tachyonic distributions. The ideal gas of tachyons is discussed, including calculations of the internal energy and entropy. In each case a comparison is made with the corresponding bradyonic results. It is found that tachyons behave just like bradyons in the high-temperature limit, but have markedly different behaviour at low temperatures.

491

Spinning tachyons as particle constituents  

International Nuclear Information System (INIS)

The motions of a classical free spinning point particle are extended to include the range of superluminal velocities. There is no formal change in the constraint-dependent functional relationship between observable mass and spin, i.e., trajectory, accompanying this extension. However, the theory now permits the specification, for superluminal velocities, of a linearly rising trajectory and naturally yields tachyon confinement. Therefore, unlike their subluminal counterparts, these tachyons can be considered candidates for elementary particle constituents.

492

Simulation aided hardening of N-channel power MOSFETs to prevent single event burnout  

International Nuclear Information System (INIS)

2D MEDICI simulator is used to investigate hardening solutions to single-event burnout (SEB). SEB parametric dependencies such as carrier lifetime reduction, base enlargement, and emitter doping decrease have been verified and a p"+ plug modification approach for SEB hardening of power MOSFETs is validated with simulations on actual device structures.

1995-07-17

493

Rock sealant restricts falling barometer effect  

International Nuclear Information System (INIS)

This rebuttal to a previous article provides new insight into the use of sprayed sealants in uranium mines. The author rejects the idea that the value of rock sealant on radon control is destroyed by changes in barometric pressure, showing that this is not necessarily true. The analyses described demonstrate that radon contamination resulting from changing barometric pressures is reduced by a rock coating. The overall use of coatings depends on their costs and effectiveness as compared with other radon control measures. 6 refs.

494

Radiation-annealing hardening of vanadium  

International Nuclear Information System (INIS)

A study is made of the mechanical properties of vanadium irradiated with fast neutrons up to dose 8.6.10"-"4 dpa, as a function of the temperature of post-radiation annealing. The radiation-annealing hardening (RAH) effect is observed at 300"oC, in agreement with previous studies. It is established for the first time that RAH is accompanied by fall in ductility. A phenomenological model is described which explains the dependence of RAH on radiation dose and temperature, as well as on the content of chemically active alloying impurities. (author).

495

Petroleum waxes in solvent systems  

Energy Technology Data Exchange (ETDEWEB)

Wax appearance temperature (WAT) of three petroleum waxes in different solvent systems under varying thermal conditions has been determined. It is observed that this temperature mainly is a function of the concentration of the wax and the solubility parameter ([delta]) of the solvent taken. This dependence of WAT has been quantified in terms of these variables in the form of mathematical equation and nomographs. (orig.)

1994-01-01

496

Methods and results of a representative analysis of the radiation exposure of the population by diagnostic radiology  

International Nuclear Information System (INIS)

From the frequency of diagnostic radiologic examinations and their radiation dose delivered to the population the risk of cancer induction and genetic damage is calculated on the basis of the risk factors given by the ICRP. Thus 0.38 % and 3 % of the total mortality for cancer and leukemia, resp., can be attributed to X-ray diagnostics. Chest examinations alone result in 0.07-0.7 damages per 100,000 persons depending on the imaging technique applied. (author).

1984-01-01

497

Inertinite of fossil coal and molecular paleontology  

British Library Electronic Table of Contents (United Kingdom)

The etching method developed made it possible to observe under the microscope the finest components of the anatomical structure of coal-forming plants. The dependence of the effectiveness of etching of tissues on the concentrations of geopolymers (protocellulose and protolignin) in them was found. The study of tissues of this kind by the methods of local analysis (for example, X-ray microanalysis) allowed us to obtain the characteristics of the above geopolymers and to use them for the identification of the primary biochemical composition of fossil organic matter.

2011-01-01

498

Higgs Chaotic Inflation  

CERN Document Server

We construct a chaotic inflation model in which the Higgs fields play the role of the inflaton in the singlet extension of the supersymmetric standard model. The key idea is to impose a shift symmetry on the D-flat direction Hu Hd in the Kahler potential. The model is a realization of the recently proposed running kinetic inflation, in which the coefficient of the kinetic term grows as the inflaton field. The inflaton potential depends on the structure of the Higgs sector. For instance, the inflaton potential is proportional to phi^{2/3} during inflation in the NMSSM.

2010-01-01

499

Effect of dietary constituents on the gastrointestinal absorption of /sup 203/Pb in man  

Energy Technology Data Exchange (ETDEWEB)

The gastrointestinal absorption of lead was markedly increased in human subjects who had fasted before ingesting lead. Food in the gut was found to reduce lead absorption, and the effect of dietary constituents on /sup 203/Pb absorption was investigated. The greatest reduction in absorption was caused by minerals. This dependence of lead absorption on dietary constituents complicates the establishment of safe levels of lead in food and water.

1983-02-01

500

Cluster-loop structure influence on molybdenum radiation hardening  

International Nuclear Information System (INIS)

Results on defect structure study and degree of molybdenum radiation hardening irradiated by fission neutrons and medium energy alpha-particles are presented. It is shown that molybdenum irradiation by alpha-particles and neutrons leads to different degree of material hardening for the same damage level. It is established that molybdenum radiation hardening is mainly defined by radiation defect clusters visible in electron microscope whose coefficient of rigidity depends on their size. 5 refs.; 6 figs.; 2 tabs. (author).

1990-05-22