Inorganic constituents in surface runoff from urbanised areas in winter: the case study of the city of Brest, Belarus

Directory of Open Access Journals (Sweden)

Ina Bulskaya

2014-03-01

Full Text Available The aim of this paper was to study the inorganic constituents of snow and snowmelt surface runoff in a case study of the city of Brest and to indicate components that could pose a threat to the environment. Samples of snow and snowmelt runoff were analysed for the following parameters: total suspended solids, pH, the contents of nitrate, phosphate and ammonium ions, and of heavy metals. The concentrations of most of these pollutants were higher in the snowmelt runoff than in snow. The concentrations of pollutants in the snowmelt surface runoff exceeded the levels established by national regulations (maximum permissible concentrations.

Pseudopotentials for calculating the bulk and surface properties of solids

International Nuclear Information System (INIS)

Cohen, M.L.

1983-01-01

A survey is presented describing research in condensed matter physics using pseudopotentials to calculate electronic, structural, and vibrational properties of solids. Semiconductors are emphasized, and both bulk and surface calculations are discussed. (author) [pt

Seasonality of selected surface water constituents in the Indian River Lagoon, Florida.

Science.gov (United States)

Qian, Y; Migliaccio, K W; Wan, Y; Li, Y C; Chin, D

2007-01-01

Seasonality is often the major exogenous effect that must be compensated for or removed to discern trends in water quality. Our objective was to provide a methodological example of trend analysis using water quality data with seasonality. Selected water quality constituents from 1979 to 2004 at three monitoring stations in southern Florida were evaluated for seasonality. The seasonal patterns of flow-weighted and log-transformed concentrations were identified by applying side-by-side boxplots and the Wilcoxon signed-rank test (p turbidity, color, and chloride), except for turbidity at Station C24S49, exhibited significant seasonal patterns. Almost all nutrient species (NO(2)-N, NH(4)-N, total Kjeldahl N, PO(4)-P, and total P) had an identical seasonal pattern of concentrations significantly greater in the wet than in the dry season. Some water quality constituents were observed to exhibit significant annual or seasonal trends. In some cases, the overall annual trend was insignificant while opposing trends were present in different seasons. By evaluating seasonal trends separately from all data, constituents can be assessed providing a more accurate interpretation of water quality trends.

SGFM applied to the calculation of surface band structure of V

International Nuclear Information System (INIS)

Baquero, R.; Velasco, V.R.; Garcia Moliner, F.

1986-07-01

The surface Green function matching (SGFM) method has been developed recently to deal with a great variety of problems in a unified way. The method was first developed for continuum systems. The recent advances for discrete structures can deal with surfaces, interfaces, quantum wells, superlattices, intercalated layered compounds, and other systems. Several applications of this formalism are being carried out. In the present note we will describe how the formalism applies to the calculation of the electronic surface band structure of vanadium which is a quite interesting transition metal with very active magnetic properties at the surface, in particular at the (100) surface. It is straightforward, on the basis of the calculation presented here, to obtain the magnetic moment on the surface, for example, through the method followed by G. Allan or the surface paramagnon density which should be particularly enhanced at this surface as compared to the bulk

Hot-electron-mediated desorption rates calculated from excited-state potential energy surfaces

DEFF Research Database (Denmark)

Olsen, Thomas; Gavnholt, Jeppe; Schiøtz, Jakob

2009-01-01

We present a model for desorption induced by (multiple) electronic transitions [DIET (DIMET)] based on potential energy surfaces calculated with the delta self-consistent field extension of density-functional theory. We calculate potential energy surfaces of CO and NO molecules adsorbed on variou...

Change of Bioactive Constituent in Clinacanthus nutans Leaves under Sun Drying

Science.gov (United States)

Abdullah, Sriyana; Aziz, Muhamad Faris Abdul

2018-03-01

Clinacanthus nutans (C. nutans) or locally known as belalai gajah is a folk medicine since ancient time. This research project was established to investigate the effects of under sun drying on the C. nutans bioactive constituent. The drying experiments were conducted using different drying surfaces i.e. perforated, black polythene and white polythene. The fresh and dried leaves were then extracted using a sonicator to evaluate its bioactive constituent. The total phenolic content (TPC) in the C. nutans extracts were determined using Follin Ciocalteu reagent method to represent the bioactive constituent. Drying over the white polythene surface showed the slowest reduction of moisture content as compared to the perforated polythene and black surfaces. Results also showed no significant effect of the drying surfaces on the TPC. However, the TPC in the dried leaves was significantly higher than in the fresh leaves. This may be due to the plant cells response to abiotic stress and the inhibition of oxidation enzymes. Therefore, drying C. nutanc leaves under sun light could be considered in order to preserve the concentration of phenolic compounds and for minimizing energy consumption.

Surface tension and related thermodynamic quantities of aqueous electrolyte solutions

CERN Document Server

Matubayasi, Norihiro

2013-01-01

Surface tension provides a thermodynamic avenue for analyzing systems in equilibrium and formulating phenomenological explanations for the behavior of constituent molecules in the surface region. While there are extensive experimental observations and established ideas regarding desorption of ions from the surfaces of aqueous salt solutions, a more successful discussion of the theory has recently emerged, which allows the quantitative calculation of the distribution of ions in the surface region. Surface Tension and Related Thermodynamic Quantities of Aqueous Electrolyte Solutions provides a d

Constituent models and large transverse momentum reactions

International Nuclear Information System (INIS)

Brodsky, S.J.

1975-01-01

The discussion of constituent models and large transverse momentum reactions includes the structure of hard scattering models, dimensional counting rules for large transverse momentum reactions, dimensional counting and exclusive processes, the deuteron form factor, applications to inclusive reactions, predictions for meson and photon beams, the charge-cubed test for the e/sup +-/p → e/sup +-/γX asymmetry, the quasi-elastic peak in inclusive hadronic reactions, correlations, and the multiplicity bump at large transverse momentum. Also covered are the partition method for bound state calculations, proofs of dimensional counting, minimal neutralization and quark--quark scattering, the development of the constituent interchange model, and the A dependence of high transverse momentum reactions

Theoretical calculations of the surface tension of Ag(1-x)-Cu(x) liquid alloys

International Nuclear Information System (INIS)

Aqra, Fathi; Ayyad, Ahmed

2011-01-01

Highlights: → A thermodynamic model for calculating the surface tension, and its temperature and composition dependences, of liquid binary alloys is described. → The model does not require the prior knowledge of the surface concentration and Gibbs energy. → The surface tension of the liquid Ag-Cu binary alloys has been calculated as a function of temperature and concentration. → The calculated values agree well with existing experimental data. - Abstract: The surface tension of silver-copper binary liquid alloys is calculated, in the frame work of Eyring theory. The calculations were made for different compositions (mole fraction, x Cu = 0, 0.2, 0.4, 0.6, 0.8 and 1), in the temperature range 1100-1800 K. The surface tension decreases with temperature increase, at a fixed copper fraction x Cu , and increases with increasing copper content. The calculated results are appropriately compared with existing literature data.

Model calculation for energy loss in ion-surface collisions

International Nuclear Information System (INIS)

Miraglia, J.E.; Gravielle, M.S.

2003-01-01

The so-called local plasma approximation is generalized to deal with projectiles colliding with surfaces of amorphous solids and with a specific crystalline structure (plannar channeling). Energy loss of protons grazingly colliding with aluminum, SnTe alloy, and LiF surfaces is investigated. The calculations agree quite well with previous theoretical results and explain the experimental findings of energy loss for aluminum and SnTe alloy, but they fall short to explain the data for LiF surfaces

A calculation of the surface recombination rate constant for hydrogen isotopes on metals

International Nuclear Information System (INIS)

Baskes, M.J.

1980-01-01

The surface recombination rate constant for hydrogen isotopes on a metal has been calculated using a simple model whose parameters may be determined by direct experimental measurements. Using the experimental values for hydrogen diffusivity, solubility, and sticking coefficient at zero surface coverage a reasonable prediction of the surface recombination constant may be made. The calculated recombination constant is in excellent agreement with experiment for bcc iron. A heuristic argument is developed which, along with the rate constant calculation, shows that surface recombination is important in those metals in which hydrogen has an exothermic heat of solution. (orig.)

The analysis of fuel constituent redistribution for ternary metallic fuel slug

Energy Technology Data Exchange (ETDEWEB)

Lee, Byoung Oon; Lee, Dong Uk; Kim, Young Kyun; Chang, Jin Wook; Lee, Ki Bok; Kim, Young Il

2004-02-01

U-TRU-Zr metallic alloy is being considered as the fuel slug for the proliferation resistance core of KALIMER. The radial fuel constituent migration is a general phenomenon in the metallic alloys. This phenomenon may affect the in-reactor performance of metallic fuel rods, influencing such factors as melting temperature, thermal conductivity, power generation rate, phase boundaries and eutectic melting of the fuel slug. Thus, constituent redistribution modeling is essential when developing a metallic fuel performance code. The constituent migration model adopted in this report was based on the Ishida's model and Hofman's theory. A subroutine program has been made and installed into the MACSIS code to simulate constituent redistribution. The radial profile of Zr redistribution was calculated for the ternary metallic fuel, and compared with the measured data.

Investigation of possibility of surface rupture derived from PFDHA and calculation of surface displacement based on dislocation

Science.gov (United States)

Inoue, N.; Kitada, N.; Irikura, K.

2013-12-01

A probability of surface rupture is important to configure the seismic source, such as area sources or fault models, for a seismic hazard evaluation. In Japan, Takemura (1998) estimated the probability based on the historical earthquake data. Kagawa et al. (2004) evaluated the probability based on a numerical simulation of surface displacements. The estimated probability indicates a sigmoid curve and increases between Mj (the local magnitude defined and calculated by Japan Meteorological Agency) =6.5 and Mj=7.0. The probability of surface rupture is also used in a probabilistic fault displacement analysis (PFDHA). The probability is determined from the collected earthquake catalog, which were classified into two categories: with surface rupture or without surface rupture. The logistic regression is performed for the classified earthquake data. Youngs et al. (2003), Ross and Moss (2011) and Petersen et al. (2011) indicate the logistic curves of the probability of surface rupture by normal, reverse and strike-slip faults, respectively. Takao et al. (2013) shows the logistic curve derived from only Japanese earthquake data. The Japanese probability curve shows the sharply increasing in narrow magnitude range by comparison with other curves. In this study, we estimated the probability of surface rupture applying the logistic analysis to the surface displacement derived from a surface displacement calculation. A source fault was defined in according to the procedure of Kagawa et al. (2004), which determined a seismic moment from a magnitude and estimated the area size of the asperity and the amount of slip. Strike slip and reverse faults were considered as source faults. We applied Wang et al. (2003) for calculations. The surface displacements with defined source faults were calculated by varying the depth of the fault. A threshold value as 5cm of surface displacement was used to evaluate whether a surface rupture reach or do not reach to the surface. We carried out the

Ab Initio Calculations for the BaTiO3 (001) Surface Structure

Institute of Scientific and Technical Information of China (English)

XUE Xu-Yan; WANG Chun-Lei; ZHONG Wei-Lie

2004-01-01

@@ The ab initio method within the local density approximation is applied to calculate cubic BaTiO3 (001) surface relaxation and rumpling for two different terminations (BaO and TiO2). Our calculations demonstrate that cubic perovskite BaTiO3 crystals possess surface polarization, accompanied by the presence of the relevant electric field.We analyse their electronic structures (band structure, density of states and the electronic density redistribution with emphasis on the covalency effects). The results are also compared with that of the previous ab initio calculations. Considerable increases of Ti-O chemical bond covalency nearby the surface have been observed.The band gap reduces especially for the TiO2 termination.

Closure certification report: TA-35 TSL-125 surface impoundment

International Nuclear Information System (INIS)

1991-01-01

This closure report documents closure activities for the TA-35 TSL-125 surface impoundment and associated structures at Los Alamos National Laboratory (the Laboratory). Prior to formal approval of the closure plan, the decision was made to proceed with closure activities to prevent any further releases from the site following informal discussions with New Mexico Environment Department (NMED) personnel. The closure plan is a revision of the previously submitted draft dated July 1988. Clean closure of the TSL-125 site was accomplished through: Removal and proper disposal of all wastes contained within the surface impoundment system; Decontamination and/or removal and proper disposal of the surface impoundment, its associated structures, and contaminated soil underlying the impoundment area; Sampling and analysis of soil to determine the presence and concentrations of any hazardous constituents remaining in the soil at the TSL-125 site; and Demonstration through a risk assessment that any constituents remaining in the soil at the TSL-125 site pose no threat to human health and the environment. All remaining soil concentrations of hazardous constituents were below health-based action levels. Analytical results indicated that benzidine, n-nitrosodimethylamine, and n-nitrosodi-n-propylamine were not detected at or above their limits of quantitation and beryllium was not present at or above its laboratory detection limit. However, the limits of quantitation and detection for these constituents were greater than their calculated health-based action levels. To demonstrate that these constituents were not present, historical data was researched and it was determined that the constituents were not utilized at the Building 125 site. 4 refs., 8 figs., 1 tab

Is there need for baryons with constituent glue

International Nuclear Information System (INIS)

Meissner, U.G.

1983-01-01

We investigate the breathing-mode spectrum of the Λ-particle in the framework of a general bag model including confinement via surface tension and volume energy. We show that the experimental states Λ 1/2 (1600) and Λ 1/2 (1800) can be described as radial surface excitations of the Λ. We further comment on a recent paper describing these Λ-excitations as baryons with constituent glue. (orig.)

Effects of surface friction treatment on the in vitro release of constituent metals from the biomedical Co–29Cr–6Mo–0.16N alloy

Energy Technology Data Exchange (ETDEWEB)

Wang, Xiaoyu [Graduate School of Engineering, Tohoku University, Sendai 980-8577 (Japan); Li, Yunping, E-mail: lyping@csu.edu.cn [State Key Lab for Powder Metallurgy, Central South University, Changsha 410083 (China); School of Materials Science and Engineering, Central South University, Changsha (China); Hou, Yuhang [Graduate School of Engineering, Tohoku University, Sendai 980-8577 (Japan); Bian, Huakang; Koizumi, Yuichiro; Chiba, Akihiko [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

2016-07-01

Due to the ignorance by many researchers on the influence of starting microstructure on the metal release of biomedical materials in human body after implant, in this study, the effect of surface friction treatment on the in vitro release of the constituent elements of the biomedical Co–29Cr–6Mo–0.16N (CCM) alloy is investigated for the first time by immersion test in lactic acid solution combined with electron backscatter diffraction, transmission electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy, and inductively coupled plasma atomic emission spectroscopy (ICP-EOS). The results indicate that friction treatment on the as-annealed CCM alloy sample surface leads to a planar strain-induced martensitic transformation (SIMT) on sample surface; this greatly accelerates the release of all the constituent elements and, in particular, that of Co as indicated by the ICP-EOS analysis. This increase can be ascribed to a localized deformation that occurred over the entire sample surface, with the dislocation density being high within the SIMTed phase and low in the alloy matrix. - Highlights: • Immersion test of biomedical CCM alloy in lactic acid solution was conducted. • Surface friction on CCM alloy leads to martensitic transformation. • The friction treatment accelerated the release of all the elements especially Co. • Localized deformation accounts for the accelerated release of elements.

Calculated surface-energy anomaly in the 3d metals

DEFF Research Database (Denmark)

Aldén, M.; Skriver, Hans Lomholt; Mirbt, S.

1992-01-01

Local-spin-density theory and a Green’s-function technique based on the linear muffin-tin orbitals method have been used to calculate the surface energy of the 3d metals. The theory explains the variation of the values derived from measurements of the surface tension of liquid metals including...... the pronounced anomaly occurring between vanadium and nickel in terms of a decrease in the d contribution caused by spin polarization....

Calculation of nuclear electromagnetic pulse propagation along the earth's surface

International Nuclear Information System (INIS)

Liang Rui; Zheng Yi; Song Lijun; Zhang Xueqin; Lip Peng

2010-01-01

It calculates the LF/VLF wave of NEMP propagation along the earth's surface. The earth-wave and the sky-wave are taken into account in the calculation. With the distance increase, the earth wave attenuates fast than the sky wave, and the time difference between the earth wave and the sky wave is reduced. (authors)

A density gradient theory based method for surface tension calculations

DEFF Research Database (Denmark)

Liang, Xiaodong; Michelsen, Michael Locht; Kontogeorgis, Georgios

2016-01-01

The density gradient theory has been becoming a widely used framework for calculating surface tension, within which the same equation of state is used for the interface and bulk phases, because it is a theoretically sound, consistent and computationally affordable approach. Based on the observation...... that the optimal density path from the geometric mean density gradient theory passes the saddle point of the tangent plane distance to the bulk phases, we propose to estimate surface tension with an approximate density path profile that goes through this saddle point. The linear density gradient theory, which...... assumes linearly distributed densities between the two bulk phases, has also been investigated. Numerical problems do not occur with these density path profiles. These two approximation methods together with the full density gradient theory have been used to calculate the surface tension of various...

Calculating the sensitivity of wind turbine loads to wind inputs using response surfaces

DEFF Research Database (Denmark)

Rinker, Jennifer M.

2016-01-01

at a low computational cost. Sobol sensitivity indices (SIs) can then be calculated with relative ease using the calibrated response surface. The proposed methodology is demonstrated by calculating the total sensitivity of the maximum blade root bending moment of the WindPACT 5 MW reference model to four......This paper presents a methodology to calculate wind turbine load sensitivities to turbulence parameters through the use of response surfaces. A response surface is a high-dimensional polynomial surface that can be calibrated to any set of input/output data and then used to generate synthetic data...... turbulence input parameters: a reference mean wind speed, a reference turbulence intensity, the Kaimal length scale, and a novel parameter reflecting the nonstationarity present in the inflow turbulence. The input/output data used to calibrate the response surface were generated for a previous project...

Calculated orientation dependence of surface segregations in Pt50Ni50

DEFF Research Database (Denmark)

Abrikosov, I. A.; Ruban, Andrei; Skriver, Hans Lomholt

1994-01-01

We present local-density calculations of surface segregation profiles in a random Pt50Ni50 alloy. We find that the concentration profiles of the three low-index surfaces oscillate and that the two most closely packed surfaces, i.e., (111) and (100), are enriched by Pt while Ni is found to segrega...

Standard Test Methods for Constituent Content of Composite Materials

CERN Document Server

American Society for Testing and Materials. Philadelphia

2009-01-01

1.1 These test methods determine the constituent content of composite materials by one of two approaches. Method I physically removes the matrix by digestion or ignition by one of seven procedures, leaving the reinforcement essentially unaffected and thus allowing calculation of reinforcement or matrix content (by weight or volume) as well as percent void volume. Method II, applicable only to laminate materials of known fiber areal weight, calculates reinforcement or matrix content (by weight or volume), and the cured ply thickness, based on the measured thickness of the laminate. Method II is not applicable to the measurement of void volume. 1.1.1 These test methods are primarily intended for two-part composite material systems. However, special provisions can be made to extend these test methods to filled material systems with more than two constituents, though not all test results can be determined in every case. 1.1.2 The procedures contained within have been designed to be particularly effective for ce...

Calculation of the surface free energy of fcc copper nanoparticles

International Nuclear Information System (INIS)

Jia Ming; Lai Yanqing; Tian Zhongliang; Liu Yexiang

2009-01-01

Using molecular dynamics simulations with the modified analytic embedded-atom method we calculate the Gibbs free energy and surface free energy for fcc Cu bulk, and further obtain the Gibbs free energy of nanoparticles. Based on the Gibbs free energy of nanoparticles, we have investigated the heat capacity of copper nanoparticles. Calculation results indicate that the Gibbs free energy and the heat capacity of nanoparticles can be divided into two parts: bulk quantity and surface quantity. The molar heat capacity of the bulk sample is lower compared with the molar heat capacity of nanoparticles, and this difference increases with the decrease in the particle size. It is also observed that the size effect on the thermodynamic properties of Cu nanoparticles is not really significant until the particle is less than about 20 nm. It is the surface atoms that decide the size effect on the thermodynamic properties of nanoparticles

Calculation of gamma-ray flux density above the Venus and Earth surfaces

International Nuclear Information System (INIS)

Surkov, Yu.A.; Manvelyan, O.S.

1987-01-01

Calculational results of dependence of flux density of nonscattered gamma-quanta on the height above the Venus and Earth planet surfaces are presented in the paper. Areas, where a certain part of gamma quanta is accumulated, are calaculted for each height. Spectra of scattered gamma quanta and their integral fluxes at different heights above the Venera planet surface are calculated. Effect of the atmosphere on gamma radiation recorded is considered. The results obtained allow to estimate optimal conditions for measuring gamma-fields above the Venus and Earth planet surfaces, to determine the area of the planet surface investigated. They are also necessary to determine the elementary composition of the rock according to the characteristic gamma radiation spectrum recorded

Iron -chromium alloys and free surfaces: from ab initio calculations to thermodynamic modeling

International Nuclear Information System (INIS)

Levesque, M.

2010-11-01

Ferritic steels possibly strengthened by oxide dispersion are candidates as structural materials for generation IV and fusion nuclear reactors. Their use is limited by incomplete knowledge of the iron-chromium phase diagram at low temperatures and of the phenomena inducing preferential segregation of one element at grain boundaries or at surfaces. In this context, this work contributes to the multi-scale study of the model iron-chromium alloy and their free surfaces by numerical simulations. This study begins with ab initio calculations of properties related to the mixture of atoms of iron and chromium. We highlight complex dependency of the magnetic moments of the chromium atoms on their local chemical environment. Surface properties are also proving sensitive to magnetism. This is the case of impurity segregation of chromium in iron and of their interactions near the surface. In a second step, we construct a simple energy model for high numerical efficiency. It is based on pair interactions on a rigid lattice to which are given local chemical environment and temperature dependencies. With this model, we reproduce the ab initio results at zero temperature and experimental results at high temperature. We also deduce the solubility limits at all intermediate temperatures with mean field approximations that we compare to Monte Carlo simulations. The last step of our work is to introduce free surfaces in our model. We then study the effect of ab initio calculated bulk and surface properties on surface segregation.Finally, we calculate segregation isotherms. We therefore propose an evolution model of surface composition of iron-chromium alloys as a function of bulk composition. which are given local chemical environment and temperature dependencies. With this model, we reproduce the ab initio results at zero temperature and experimental results at high temperature. We also deduce the solubility limits at all intermediate temperatures with mean field approximations that

Scheil-Gulliver Constituent Diagrams

Science.gov (United States)

Pelton, Arthur D.; Eriksson, Gunnar; Bale, Christopher W.

2017-06-01

During solidification of alloys, conditions often approach those of Scheil-Gulliver cooling in which it is assumed that solid phases, once precipitated, remain unchanged. That is, they no longer react with the liquid or with each other. In the case of equilibrium solidification, equilibrium phase diagrams provide a valuable means of visualizing the effects of composition changes upon the final microstructure. In the present study, we propose for the first time the concept of Scheil-Gulliver constituent diagrams which play the same role as that in the case of Scheil-Gulliver cooling. It is shown how these diagrams can be calculated and plotted by the currently available thermodynamic database computing systems that combine Gibbs energy minimization software with large databases of optimized thermodynamic properties of solutions and compounds. Examples calculated using the FactSage system are presented for the Al-Li and Al-Mg-Zn systems, and for the Au-Bi-Sb-Pb system and its binary and ternary subsystems.

Calculating the sensitivity of wind turbine loads to wind inputs using response surfaces

International Nuclear Information System (INIS)

Rinker, Jennifer M.

2016-01-01

This paper presents a methodology to calculate wind turbine load sensitivities to turbulence parameters through the use of response surfaces. A response surface is a highdimensional polynomial surface that can be calibrated to any set of input/output data and then used to generate synthetic data at a low computational cost. Sobol sensitivity indices (SIs) can then be calculated with relative ease using the calibrated response surface. The proposed methodology is demonstrated by calculating the total sensitivity of the maximum blade root bending moment of the WindPACT 5 MW reference model to four turbulence input parameters: a reference mean wind speed, a reference turbulence intensity, the Kaimal length scale, and a novel parameter reflecting the nonstationarity present in the inflow turbulence. The input/output data used to calibrate the response surface were generated for a previous project. The fit of the calibrated response surface is evaluated in terms of error between the model and the training data and in terms of the convergence. The Sobol SIs are calculated using the calibrated response surface, and the convergence is examined. The Sobol SIs reveal that, of the four turbulence parameters examined in this paper, the variance caused by the Kaimal length scale and nonstationarity parameter are negligible. Thus, the findings in this paper represent the first systematic evidence that stochastic wind turbine load response statistics can be modeled purely by mean wind wind speed and turbulence intensity. (paper)

Direct Monte Carlo dose calculation using polygon-surface computational human model

International Nuclear Information System (INIS)

Jeong, Jong Hwi; Kim, Chan Hyeong; Yeom, Yeon Su; Cho, Sungkoo; Chung, Min Suk; Cho, Kun-Woo

2011-01-01

In the present study, a voxel-type computational human model was converted to a polygon-surface model, after which it was imported directly to the Geant4 code without using a voxelization process, that is, without converting back to a voxel model. The original voxel model was also imported to the Geant4 code, in order to compare the calculated dose values and the computational speed. The average polygon size of the polygon-surface model was ∼0.5 cm 2 , whereas the voxel resolution of the voxel model was 1.981 × 1.981 × 2.0854 mm 3 . The results showed a good agreement between the calculated dose values of the two models. The polygon-surface model was, however, slower than the voxel model by a factor of 6–9 for the photon energies and irradiation geometries considered in the present study, which nonetheless is considered acceptable, considering that direct use of the polygon-surface model does not require a separate voxelization process. (author)

[Effects of Lime on Seedling Growth,Yield and Volatile Constituents of Atractylodes lancea].

Science.gov (United States)

Zhang, Yan; Miki, Sakurai; Chen, Mei-lan; Takeda, Xiuji; Zhao, Dong-yue; Kang, Li-ping; Guo, Lan-ping

2015-03-01

To investigate the effects of different amounts of lime on yield and quality of Atractylodes lancea, and to provide reference for the herb growing site soil improvement and self-poisoning ease. Add different gradients of lime, and then measure their growth targets, yield and four kinds of volatile constituents content(hinesol, atractylone, β-eudesmol and atractylodin). Volatile constituents yield per plant was calculated. Adding 160 g/m2 lime had a significant role in promoting the growth and yield of herb; Adding 80 g/m2 lime was conducive to the volatile constituents production, and adding lime decreased the atractylone and atractylodin content, while increased the hinesol and β-eudesmol content; Adding 160 g/m2 lime promoted the volatile constituents yield per plant. Adding lime plays a role of neutralize soil pH, antibacteria and prevention incognita, and has a certain degree of ease autotoxicity and obstacle,and then promotes the yield and volatile constituents production of Atractylodes lancea.

Activity guided isolation of chemical constituents from the ...

African Journals Online (AJOL)

In this study we investigated the chemical constituents of bioactive methanol extract of Euphorbia schimperi C. Presl. For this the methanol extract was fractionated into 20, 40, 60, 80% MeOH in CHCl3, and 100% MeOH fractions respectively by vacuum liquid chromatography. Excision wound surface of the animals were ...

Surface impedance of superconductors in wide frequency ranges for wake field calculations

International Nuclear Information System (INIS)

Davidovskii, V.G.

2006-01-01

The problem of the surface impedance of superconductors in wide frequency ranges for calculations of wake fields, generated by bunches of charged particles moving axially inside a metallic vacuum chambers, is solved. The case of specular electron reflection at the superconductor surface is considered. The expression for the surface impedance of superconductors suitable for numerical computation is derived [ru

Calculation of the surface energy of hcp-metals with the empirical electron theory

International Nuclear Information System (INIS)

Fu Baoqin; Liu Wei; Li Zhilin

2009-01-01

A brief introduction of the surface model based on the empirical electron theory (EET) and the dangling bond analysis method (DBAM) is presented in this paper. The anisotropy of spatial distribution of covalent bonds of hexagonal close-packed (hcp) metals such as Be, Mg, Sc, Ti, Co, Zn, Y, Zr, Tc, Cd, Hf, and Re, has been analyzed. And under the first-order approximation, the calculated surface energy values for low index surfaces of these hcp-metals are in agreement with experimental and other theoretical values. Correlated analysis showed that the anisotropy of surface energy of hcp-metals was related with the ratio of lattice constants (c/a). The calculation method for the research of surface energy provides a good basis for models of surface science phenomena, and the model may be extended to the surface energy estimation of more metals, alloys, ceramics, and so on, since abundant information about the valence electronic structure (VES) is generated from EET.

Sivers function in constituent quark models

CERN Document Server

Scopetta, S.; Fratini, F.; Vento, V.

2008-01-01

A formalism to evaluate the Sivers function, developed for calculations in constituent quark models, is applied to the Isgur-Karl model. A non-vanishing Sivers asymmetry, with opposite signs for the u and d flavor, is found; the Burkardt sum rule is fulfilled up to 2 %. Nuclear effects in the extraction of neutron single spin asymmetries in semi-inclusive deep inelastic scattering off 3He are also evaluated. In the kinematics of JLab, it is found that the nuclear effects described by an Impulse Approximation approach are under control.

Optimal sizing method for constituent elements of stand-alone photovoltaic power systems

Energy Technology Data Exchange (ETDEWEB)

Otsuka, Hirotada; Oi, Yoichi [Hokuriku Electric Power Co., Inc. Toyama (Japan)

1988-12-25

The purpose of the report was to calculate the optimal volume of constituent elements of stand-alone photovoltaic power systems, based on the distribution of global radiation on an inclined surface (herein-after called flux of solar radiation), which had been previously measured, and the size of load to be supplied. The least power generation cost was calculated, supposing that setting load was 176kWh/month and the loss of load probability (LOLP) was 1%, by using actual amount of solar radiation in May 1985. The cost was divided into two components: one was proportionate to the size of solar cell, and the other was in proportion to the battery volume. And then, the cost of twenty-year operation(TLC) was calculated. The size of array and the battery volume, which minimize the cost, can be determined when TLC is differentiate. Since auxiliary power source is not attached to this system, it is necessary to restrict the load in order to meet the electric power shortage. In case of the cost at construction in 1984, a standard model indicating the least power generation cost is a photovoltaic system with the array size of A=49.0m{sup 2} and the battery volume of Q=568(Ah). 4 refs., 9 figs., 10 tabs.

DESIGN AND CALCULATION OF AERODROMECOAING WITH HEATED SURFACE LAYERS

Directory of Open Access Journals (Sweden)

Vadim G. Piskunov

2009-04-01

Full Text Available  The developed constructions with heated by surface layers for aerodromes and auto roads when developed composition of electroconductive concrete reinforced with chemical electrical conductive fibres being used was researched. The experimentally obtained characteristics of ended conductive concrete reinforced with fibers were presented. Calculation by developed heated construction of shell was made.

Analysis of gamma irradiated pepper constituents, 5

International Nuclear Information System (INIS)

Takagi, Kazuko; Okuyama, Tsuneo; Ishikawa, Toshihiro.

1988-01-01

Gamma irradiated peppers (10 krad, 100 krad, 1 Mrad) were analyzed by HPLC. The extraction method and HPLC conditions were same as the first report, that is, the extraction from pepper was performed by Automatic Air Hammer and the extracted samples were separated on a reversed phase C 8 column with a concave gradient from 0.1% trifluoro aceticacid (TFA) in water to 75% acetonitrile-0.1% TFA in water for 60 minutes and detected at 210 nm, 280 nm. It is difficult to compare with irradiated and unirradiated pepper constituents by their peak height or area. And the method of multi variant statistically analysis was introduced. The 'peak n area/peak n + 1 area' ratio was calculated by computer. Each peak area was accounted by integrator. The value of these ratio were called 'parameter'. Each chromatogram has 741 parameters calculated with 39 chromatographic peaks. And these parameters were abopted to the multi variant statiscally analysis. Comparison of constituents between irradiated pepper and unirradiated pepper was done by 741 parameters. The correlation of parameters between irradiated and unirradiated was investigated by use of computer. Some parameters of irradiated case were selected as which had no correlation with unirradiated case. That is to say these parameters were thought to be changed with gamma spectrum irradiation. By this method, Coumarin was identified as a changed component with gamma irradiation. (author)

High resolution electron energy loss spectroscopy of clean and hydrogen covered Si(001) surfaces: first principles calculations.

Science.gov (United States)

Patterson, C H

2012-09-07

Surface phonons, conductivities, and loss functions are calculated for reconstructed (2×1), p(2×2) and c(4×2) clean Si(001) surfaces, and (2×1) H and D covered Si(001) surfaces. Surface conductivities perpendicular to the surface are significantly smaller than conductivities parallel to the surface. The surface loss function is compared to high resolution electron energy loss measurements. There is good agreement between calculated loss functions and experiment for H and D covered surfaces. However, agreement between experimental data from different groups and between theory and experiment is poor for clean Si(001) surfaces. Formalisms for calculating electron energy loss spectra are reviewed and the mechanism of electron energy losses to surface vibrations is discussed.

Hydrodynamical model with massless constituents

International Nuclear Information System (INIS)

Chiu, C.B.; Wang, K.H.

1974-01-01

Within the constituent hydrodynamical model, it is shown that the total number of constituents is conserved, if these constituents are massless and satisfy the Fermi-Dirac distribution. A simple scheme for the transition from the constituent-phase to the hadron-phase is suggested, and the hadron inclusive momentum spectra are presented for this case. This phase transition scheme predicts the average transverse momentum of meson resonances which is compatible with the data. (U.S.)

The calculation of surface free energy based on embedded atom method for solid nickel

International Nuclear Information System (INIS)

Luo Wenhua; Hu Wangyu; Su Kalin; Liu Fusheng

2013-01-01

Highlights: ► A new solution for accurate prediction of surface free energy based on embedded atom method was proposed. ► The temperature dependent anisotropic surface energy of solid nickel was obtained. ► In isotropic environment, the approach does not change most predictions of bulk material properties. - Abstract: Accurate prediction of surface free energy of crystalline metals is a challenging task. The theory calculations based on embedded atom method potentials often underestimate surface free energy of metals. With an analytical charge density correction to the argument of the embedding energy of embedded atom method, an approach to improve the prediction for surface free energy is presented. This approach is applied to calculate the temperature dependent anisotropic surface energy of bulk nickel and surface energies of nickel nanoparticles, and the obtained results are in good agreement with available experimental data.

Parton distributions and EMC ratios of the 6Li nucleus in the constituent quark exchange model

Science.gov (United States)

Modarres, M.; Hadian, A.

2017-10-01

While the constituent quark model (CQM), in which the quarks are assumed to be the complex objects, is used to calculate the parton distribution functions of the iso-scalar lithium-6 (6Li) nucleus, the u-d constituent quark distribution functions of the 6Li nucleus are evaluated from the valence quark exchange formalism (VQEF) for the A = 6 iso-scalar system. After computing the valence quark, sea quark, and gluon distribution functions in the constituent quark exchange model (CQEM, i.e., CQM +VQEF), the nucleus structure function is calculated for the 6Li nucleus at the leading order (LO) and the next-to-leading-order (NLO) levels to extract the European muon collaboration (EMC) ratio, at different hard scales, using the standard Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGALP) evolution equations. The outcomes are compared with those of our previous works and the available NMC experimental data, and various physical points are discussed. It is observed that the present EMC ratios are considerably improved compared with those of our previous works, in which only the valence quark distributions were considered to calculate the EMC ratio, and are closer to the NMC data. Finally, it is concluded that at a given appropriate hard scale, the LO approximation may be enough for calculating the nucleus EMC ratio.

use of the RESRAD-BUILD code to calculate building surface contamination limits

International Nuclear Information System (INIS)

Faillace, E.R.; LePoire, D.; Yu, C.

1996-01-01

Surface contamination limits in buildings were calculated for 226 Ra, 230 Th, 232 Th, and natural uranium on the basis of 1 mSv y -1 (100 mrem y -1 ) dose limit. The RESRAD-BUILD computer code was used to calculate these limits for two scenarios: building occupancy and building renovation. RESRAD-BUILD is a pathway analysis model designed to evaluate the potential radiological dose incurred by individuals working or living inside a building contaminated with radioactive material. Six exposure pathways are considered in the RESRAD-BUILD code: (1) external exposure directly from the source; (2) external exposure from materials deposited on the floor; (3) external exposure due to air submersion; (4) inhalation of airborne radioactive particles; (5) inhalation of aerosol indoor radon progeny; and (6) inadvertent ingestion of radioactive material, either directly from the sources or from materials deposited on the surfaces. The code models point, line, area, and volume sources and calculates the effects of radiation shielding, building ventilation, and ingrowth of radioactive decay products. A sensitivity analysis was performed to determine how variations in input parameters would affect the surface contamination limits. In most cases considered, inhalation of airborne radioactive particles was the primary exposure pathway. However, the direct external exposure contribution from surfaces contaminated with 226 Ra was in some cases the dominant pathway for building occupancy depending on the room size, ventilation rates, and surface release fractions. The surface contamination limits are most restrictive for 232 Th, followed by 230 Th, natural uranium, and 226 Ra. The results are compared with the surface contamination limits in the Nuclear Regulatory Commission's Regulatory Guide 1.86, which are most restrictive for 226 Ra and 230 Th, followed by 232 Th, and are least restrictive for natural uranium

Discrete lattice plane broken bond interfacial energy calculations and the use of the dividing surface concept

International Nuclear Information System (INIS)

Ramanujan, R.V.

2003-01-01

The concept of the dividing surface has been extensively used to define the relationships between thermodynamic quantities at the interface between two phases; it is also useful in calculations of interfacial energy (γ). However, in the original formulation, the two phases are continuum phases, the atomistic nature of the interface was not considered. It is, therefore, useful to examine the use of the dividing surface in the context of atomistic interfacial energy calculations. The case of a planar fcc:hcp interface is considered and the dividing surface positions which are useful in atomistic interfacial energy calculations are stated, one position equates γ to the excess internal energy, the other position allows us to use the Gibbs adsorption equation. An example of a calculation using the convenient dividing surface positions is presented

First principles study of hydroxyapatite surface

Science.gov (United States)

Slepko, Alexander; Demkov, Alexander A.

2013-07-01

The biomineral hydroxyapatite (HA) [Ca10(PO4)6(OH)2] is the main mineral constituent of mammal bone. We report a theoretical investigation of the HA surface. We identify the low energy surface orientations and stoichiometry under a variety of chemical environments. The surface most stable in the physiologically relevant OH-rich environment is the OH-terminated (1000) surface. We calculate the work function of HA and relate it to the surface composition. For the lowest energy OH-terminated surface we find the work function of 5.1 eV, in close agreement with the experimentally reported range of 4.7 eV-5.1 eV [V. S. Bystrov, E. Paramonova, Y. Dekhtyar, A. Katashev, A. Karlov, N. Polyaka, A. V. Bystrova, A. Patmalnieks, and A. L. Kholkin, J. Phys.: Condens. Matter 23, 065302 (2011), 10.1088/0953-8984/23/6/065302].

Three-phase short circuit calculation method based on pre-computed surface for doubly fed induction generator

Science.gov (United States)

Ma, J.; Liu, Q.

2018-02-01

This paper presents an improved short circuit calculation method, based on pre-computed surface to determine the short circuit current of a distribution system with multiple doubly fed induction generators (DFIGs). The short circuit current, injected into power grid by DFIG, is determined by low voltage ride through (LVRT) control and protection under grid fault. However, the existing methods are difficult to calculate the short circuit current of DFIG in engineering practice due to its complexity. A short circuit calculation method, based on pre-computed surface, was proposed by developing the surface of short circuit current changing with the calculating impedance and the open circuit voltage. And the short circuit currents were derived by taking into account the rotor excitation and crowbar activation time. Finally, the pre-computed surfaces of short circuit current at different time were established, and the procedure of DFIG short circuit calculation considering its LVRT was designed. The correctness of proposed method was verified by simulation.

Capturing optically important constituents and properties in a marine biogeochemical and ecosystem model

Science.gov (United States)

Dutkiewicz, S.; Hickman, A. E.; Jahn, O.; Gregg, W. W.; Mouw, C. B.; Follows, M. J.

2015-07-01

We present a numerical model of the ocean that couples a three-stream radiative transfer component with a marine biogeochemical-ecosystem component in a dynamic three-dimensional physical framework. The radiative transfer component resolves the penetration of spectral irradiance as it is absorbed and scattered within the water column. We explicitly include the effect of several optically important water constituents (different phytoplankton functional types; detrital particles; and coloured dissolved organic matter, CDOM). The model is evaluated against in situ-observed and satellite-derived products. In particular we compare to concurrently measured biogeochemical, ecosystem, and optical data along a meridional transect of the Atlantic Ocean. The simulation captures the patterns and magnitudes of these data, and estimates surface upwelling irradiance analogous to that observed by ocean colour satellite instruments. We find that incorporating the different optically important constituents explicitly and including spectral irradiance was crucial to capture the variability in the depth of the subsurface chlorophyll a (Chl a) maximum. We conduct a series of sensitivity experiments to demonstrate, globally, the relative importance of each of the water constituents, as well as the crucial feedbacks between the light field, the relative fitness of phytoplankton types, and the biogeochemistry of the ocean. CDOM has proportionally more importance at attenuating light at short wavelengths and in more productive waters, phytoplankton absorption is relatively more important at the subsurface Chl a maximum, and water molecules have the greatest contribution when concentrations of other constituents are low, such as in the oligotrophic gyres. Scattering had less effect on attenuation, but since it is important for the amount and type of upwelling irradiance, it is crucial for setting sea surface reflectance. Strikingly, sensitivity experiments in which absorption by any of the

Tetrahedral cluster and pseudo molecule: New approaches to Calculate Absolute Surface Energy of Zinc Blende (111)/(-1-1-1) Surface

Science.gov (United States)

Zhang, Yiou; Zhang, Jingzhao; Tse, Kinfai; Wong, Lun; Chan, Chunkai; Deng, Bei; Zhu, Junyi

Determining accurate absolute surface energies for polar surfaces of semiconductors has been a great challenge in decades. Here, we propose pseudo-hydrogen passivation to calculate them, using density functional theory approaches. By calculating the energy contribution from pseudo-hydrogen using either a pseudo molecule method or a tetrahedral cluster method, we obtained (111)/(-1-1-1) surfaces energies of Si, GaP, GaAs, and ZnS with high self-consistency. Our findings may greatly enhance the basic understandings of different surfaces and lead to novel strategies in the crystal growth. We would like to thank Su-huai Wei for helpful discussions. Computing resources were provided by the High Performance Cluster Computing Centre, Hong Kong Baptist University. This work was supported by the start-up funding and direct Grant with the Project.

Calculation of surface acoustic waves in a multilayered piezoelectric structure

International Nuclear Information System (INIS)

Zhang Zuwei; Wen Zhiyu; Hu Jing

2013-01-01

The propagation properties of the surface acoustic waves (SAWs) in a ZnO—SiO 2 —Si multilayered piezoelectric structure are calculated by using the recursive asymptotic method. The phase velocities and the electromechanical coupling coefficients for the Rayleigh wave and the Love wave in the different ZnO—SiO 2 —Si structures are calculated and analyzed. The Love mode wave is found to be predominantly generated since the c-axis of the ZnO film is generally perpendicular to the substrate. In order to prove the calculated results, a Love mode SAW device based on the ZnO—SiO 2 —Si multilayered structure is fabricated by micromachining, and its frequency responses are detected. The experimental results are found to be mainly consistent with the calculated ones, except for the slightly larger velocities induced by the residual stresses produced in the fabrication process of the films. The deviation of the experimental results from the calculated ones is reduced by thermal annealing. (semiconductor physics)

Volume and surface photoemission from tungsten. I. Calculation of band structure and emission spectra

DEFF Research Database (Denmark)

Christensen, N. Egede; Feuerbacher, B.

1974-01-01

is obtained from an ad hoc potential based on a Dirac-Slater atomic calculation for the ground-state configuration and with full Slater exchange in the atomic as well as in the crystal potential. The selection of this best potential is justified by comparing the calculated band structure to Fermi...... of states. The present work includes a crude estimate of this surface density of states, which is derived from the bulk band structure by narrowing the d bands according to an effective number of neighbors per surface atom. Estimates of surface relaxation effects are also included.......The electronic energy-band structure of tungsten has been calculated by means of the relativistic-augmented-plane-wave method. A series of mutually related potentials are constructed by varying the electronic configuration and the amount of Slater exchange included. The best band structure...

Detection analysis of surface hydroxyl active sites and simulation calculation of the surface dissociation constants of aqueous diatomite suspensions

International Nuclear Information System (INIS)

Ma, Shu-Cui; Wang, Zhi-Gang; Zhang, Ji-Lin; Sun, De-Hui; Liu, Gui-Xia

2015-01-01

Highlights: • To examine surface hydroxyl functional groups of the calcined diatomite by TGA-DSC, FTIR, and XPS. • To calculate the optimized log K 1 , log K 2 and log C values and the surface species distribution of each surface reactive site using ProtoFit and PHREEQC, respectively. - Abstract: The surface properties of the diatomite were investigated using nitrogen adsorption/deadsorption isotherms, TG-DSC, FTIR, and XPS, and surface protonation–deprotonation behavior was determined by continuous acid–base potentiometric titration technique. The diatomite sample with porous honeycomb structure has a BET specific surface area of 10.21 m 2 /g and large numbers of surface hydroxyl functional groups (i.e. ≡Si-OH, ≡Fe-OH, and ≡Al-OH). These surface hydroxyls can be protonated or deprotonated depending on the pH of the suspension. The experimental potentiometric data in two different ionic strength solutions (0.1 and 0.05 mol/L NaCl) were fitted using ProtoFit GUI V2.1 program by applying diffuse double layer model (DLM) with three amphoteric sites and minimizing the sum of squares between a dataset derivative function and a model derivative function. The optimized surface parameters (i.e. surface dissociation constants (log K 1 , log K 2 ) and surface site concentrations (log C)) of the sample were obtained. Based on the optimized surface parameters, the surface species distribution was calculated using Program-free PHREEQC 3.1.2. Thus, this work reveals considerable new information about surface protonation–deprotonation processes and surface adsorptive behaviors of the diatomite, which helps us to effectively use the cheap and cheerful diatomite clay adsorbent

Detection analysis of surface hydroxyl active sites and simulation calculation of the surface dissociation constants of aqueous diatomite suspensions

Energy Technology Data Exchange (ETDEWEB)

Ma, Shu-Cui [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Key Laboratory of Applied Chemistry and Nanotechnology at Universities of Jilin Province, Changchun University of Science and Technology, Changchun 130022 (China); Wang, Zhi-Gang [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Zhang, Ji-Lin, E-mail: zjl@ciac.ac.cn [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Sun, De-Hui [Changchun Institute Technology, Changchun 130012 (China); Liu, Gui-Xia, E-mail: liuguixia22@163.com [Key Laboratory of Applied Chemistry and Nanotechnology at Universities of Jilin Province, Changchun University of Science and Technology, Changchun 130022 (China)

2015-02-01

Highlights: • To examine surface hydroxyl functional groups of the calcined diatomite by TGA-DSC, FTIR, and XPS. • To calculate the optimized log K{sub 1}, log K{sub 2} and log C values and the surface species distribution of each surface reactive site using ProtoFit and PHREEQC, respectively. - Abstract: The surface properties of the diatomite were investigated using nitrogen adsorption/deadsorption isotherms, TG-DSC, FTIR, and XPS, and surface protonation–deprotonation behavior was determined by continuous acid–base potentiometric titration technique. The diatomite sample with porous honeycomb structure has a BET specific surface area of 10.21 m{sup 2}/g and large numbers of surface hydroxyl functional groups (i.e. ≡Si-OH, ≡Fe-OH, and ≡Al-OH). These surface hydroxyls can be protonated or deprotonated depending on the pH of the suspension. The experimental potentiometric data in two different ionic strength solutions (0.1 and 0.05 mol/L NaCl) were fitted using ProtoFit GUI V2.1 program by applying diffuse double layer model (DLM) with three amphoteric sites and minimizing the sum of squares between a dataset derivative function and a model derivative function. The optimized surface parameters (i.e. surface dissociation constants (log K{sub 1}, log K{sub 2}) and surface site concentrations (log C)) of the sample were obtained. Based on the optimized surface parameters, the surface species distribution was calculated using Program-free PHREEQC 3.1.2. Thus, this work reveals considerable new information about surface protonation–deprotonation processes and surface adsorptive behaviors of the diatomite, which helps us to effectively use the cheap and cheerful diatomite clay adsorbent.

Density-functional calculations of the surface tension of liquid Al and Na

Science.gov (United States)

Stroud, D.; Grimson, M. J.

1984-01-01

Calculations of the surface tensions of liquid Al and Na are described using the full ionic density functional formalism of Wood and Stroud (1983). Surface tensions are in good agreement with experiment in both cases, with results substantially better for Al than those found previously in the gradient approximation. Preliminary minimization with respect to surface profile leads to an oscillatory profile superimposed on a nearly steplike ionic density disribution; the oscillations have a wavellength of about a hardsphere diameter.

Electrochemical dissolution of surface alloys in acids: Thermodynamic trends from first-principles calculations

DEFF Research Database (Denmark)

Greeley, Jeffrey Philip; Nørskov, Jens Kehlet

2007-01-01

A simple procedure is introduced to use periodic Density Functional Theory calculations to estimate trends in the thermodynamics of surface alloy dissolution in acidic media. With this approach, the dissolution potentials for solute metal atoms embedded in the surface layer of various host metals...

Calculation of Pressure Distribution at Rotary Body Surface with the Vortex Element Method

Directory of Open Access Journals (Sweden)

S. A. Dergachev

2014-01-01

Full Text Available Vortex element method allows to simulate unsteady hydrodynamic processes in incompressible environment, taking into account the evolution of the vortex sheet, including taking into account the deformation or moving of the body or part of construction.For the calculation of the hydrodynamic characteristics of the method based on vortex element software package was developed MVE3D. Vortex element (VE in program is symmetrical Vorton-cut. For satisfying the boundary conditions at the surface used closed frame of vortons.With this software system modeled incompressible flow around a cylindrical body protection elongation L / D = 13 with a front spherical blunt with the angle of attack of 10 °. We analyzed the distribution of the pressure coefficient on the body surface of the top and bottom forming.The calculate results were compared with known Results of experiment.Considered design schemes with different number of Vorton framework. Also varied radius of VE. Calculation make possible to establish the degree of sampling surface needed to produce close to experiment results. It has been shown that an adequate reproducing the pressure distribution in the transition region spherical cylindrical surface, on the windward side requires a high degree of sampling.Based on these results Can be possible need to improve on the design scheme of body's surface, allowing more accurate to describe the flow vorticity in areas with abrupt changes of geometry streamlined body.

Ammonia synthesis over a Ru(0001) surface studied by density functional calculations

DEFF Research Database (Denmark)

Logadottir, Ashildur; Nørskov, Jens Kehlet

2003-01-01

In this paper we present DFT studies of all the elementary steps in the synthesis of ammonia from gaseous hydrogen and nitrogen over a ruthenium crystal. The stability and configurations of intermediates in the ammonia synthesis over a Ru(0001) surface have been investigated, both over a flat...... surface and over a stepped surface. The calculations show that the step sites on the surface are much more reactive than the terrace sites. The DFT results are then used to study the mechanism of promotion by alkalies over the Ru(0001) and to determine the rate-determining step in the synthesis of ammonia...

Metadyn View: Fast web-based viewer of free energy surfaces calculated by metadynamics

Science.gov (United States)

Hošek, Petr; Spiwok, Vojtěch

2016-01-01

Metadynamics is a highly successful enhanced sampling technique for simulation of molecular processes and prediction of their free energy surfaces. An in-depth analysis of data obtained by this method is as important as the simulation itself. Although there are several tools to compute free energy surfaces from metadynamics data, they usually lack user friendliness and a build-in visualization part. Here we introduce Metadyn View as a fast and user friendly viewer of bias potential/free energy surfaces calculated by metadynamics in Plumed package. It is based on modern web technologies including HTML5, JavaScript and Cascade Style Sheets (CSS). It can be used by visiting the web site and uploading a HILLS file. It calculates the bias potential/free energy surface on the client-side, so it can run online or offline without necessity to install additional web engines. Moreover, it includes tools for measurement of free energies and free energy differences and data/image export.

Coating with luminal gut-constituents alters adherence of nanoparticles to intestinal epithelial cells

Directory of Open Access Journals (Sweden)

Heike Sinnecker

2014-12-01

Full Text Available Background: Anthropogenic nanoparticles (NPs have found their way into many goods of everyday life. Inhalation, ingestion and skin contact are potential routes for NPs to enter the body. In particular the digestive tract with its huge absorptive surface area provides a prime gateway for NP uptake. Considering that NPs are covered by luminal gut-constituents en route through the gastrointestinal tract, we wanted to know if such modifications have an influence on the interaction between NPs and enterocytes.Results: We investigated the consequences of a treatment with various luminal gut-constituents on the adherence of nanoparticles to intestinal epithelial cells. Carboxylated polystyrene particles 20, 100 and 200 nm in size represented our anthropogenic NPs, and differentiated Caco-2 cells served as model for mature enterocytes of the small intestine. Pretreatment with the proteins BSA and casein consistently reduced the adherence of all NPs to the cultured enterocytes, while incubation of NPs with meat extract had no obvious effect on particle adherence. In contrast, contact with intestinal fluid appeared to increase the particle-cell interaction of 20 and 100 nm NPs.Conclusion: Luminal gut-constituents may both attenuate and augment the adherence of NPs to cell surfaces. These effects appear to be dependent on the particle size as well as on the type of interacting protein. While some proteins will rather passivate particles towards cell attachment, possibly by increasing colloid stability or camouflaging attachment sites, certain components of intestinal fluid are capable to modify particle surfaces in such a way that interactions with cellular surface structures result in an increased binding.

Calculation of surface potentials at the silica–water interface using molecular dynamics: Challenges and opportunities

Science.gov (United States)

Lowe, Benjamin M.; Skylaris, Chris-Kriton; Green, Nicolas G.; Shibuta, Yasushi; Sakata, Toshiya

2018-04-01

Continuum-based methods are important in calculating electrostatic properties of interfacial systems such as the electric field and surface potential but are incapable of providing sufficient insight into a range of fundamentally and technologically important phenomena which occur at atomistic length-scales. In this work a molecular dynamics methodology is presented for interfacial electric field and potential calculations. The silica–water interface was chosen as an example system, which is highly relevant for understanding the response of field-effect transistors sensors (FET sensors). Detailed validation work is presented, followed by the simulated surface charge/surface potential relationship. This showed good agreement with experiment at low surface charge density but at high surface charge density the results highlighted challenges presented by an atomistic definition of the surface potential. This methodology will be used to investigate the effect of surface morphology and biomolecule addition; both factors which are challenging using conventional continuum models.

Constituency Orientation in Irish Politics

DEFF Research Database (Denmark)

Kusche, Isabel

2017-01-01

The constituency orientation of Irish politicians is a recurring topic in Irish political science. Its analysis has predominantly focused on TDs. This article uses a content analysis of candidate video statements in the general election 2016 in order to assess the strength of constituency...... this pattern, indicated by the weak constituency orientation in Dublin and Cork constituencies. Results also indicate differences between parties and some political statuses, while the gender of the candidates is of no relevance. Although the material does not permit a clear distinction between effects...... of political culture and short-term considerations, taken together the results indicate that localism in Irish politics matters, but in more complicated ways than usually depicted....

Surface complexation modeling calculation of Pb(II) adsorption onto the calcined diatomite

Science.gov (United States)

Ma, Shu-Cui; Zhang, Ji-Lin; Sun, De-Hui; Liu, Gui-Xia

2015-12-01

Removal of noxious heavy metal ions (e.g. Pb(II)) by surface adsorption of minerals (e.g. diatomite) is an important means in the environmental aqueous pollution control. Thus, it is very essential to understand the surface adsorptive behavior and mechanism. In this work, the Pb(II) apparent surface complexation reaction equilibrium constants on the calcined diatomite and distributions of Pb(II) surface species were investigated through modeling calculations of Pb(II) based on diffuse double layer model (DLM) with three amphoteric sites. Batch experiments were used to study the adsorption of Pb(II) onto the calcined diatomite as a function of pH (3.0-7.0) and different ionic strengths (0.05 and 0.1 mol L-1 NaCl) under ambient atmosphere. Adsorption of Pb(II) can be well described by Freundlich isotherm models. The apparent surface complexation equilibrium constants (log K) were obtained by fitting the batch experimental data using the PEST 13.0 together with PHREEQC 3.1.2 codes and there is good agreement between measured and predicted data. Distribution of Pb(II) surface species on the diatomite calculated by PHREEQC 3.1.2 program indicates that the impurity cations (e.g. Al3+, Fe3+, etc.) in the diatomite play a leading role in the Pb(II) adsorption and dominant formation of complexes and additional electrostatic interaction are the main adsorption mechanism of Pb(II) on the diatomite under weak acidic conditions.

7 CFR 930.16 - Sales constituency.

Science.gov (United States)

2010-01-01

... Definitions § 930.16 Sales constituency. Sales constituency means a common marketing organization or brokerage... 7 Agriculture 8 2010-01-01 2010-01-01 false Sales constituency. 930.16 Section 930.16 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements...

Practical Calculation of Thermal Deformation and Manufacture Error uin Surface Grinding

Institute of Scientific and Technical Information of China (English)

周里群; 李玉平

2002-01-01

The paper submits a method to calculate thermal deformation and manufacture error in surface grinding.The author established a simplified temperature field model.and derived the thermal deformaiton of the ground workpiece,It is found that there exists not only a upwarp thermal deformation,but also a parallel expansion thermal deformation.A upwarp thermal deformation causes a concave shape error on the profile of the workpiece,and a parallel expansion thermal deformation causes a dimension error in height.The calculations of examples are given and compared with presented experiment data.

Study on the surface hydroxyl group on solid breeding materials by ab-initio calculations

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Satoru; Taniguchi, Masaki [Tokyo Univ. (Japan). Faculty of Engineering

1996-10-01

The nature of -OH on the surface of Li{sub 2}O was analyzed with the ab-initio quantum chemical calculation technique. Calculation results showed that the stretching vibration of O-H is affected by the chemical species around the -OH. (author)

Adsorption configuration of magnesium on wurtzite gallium nitride surface using first-principles calculations

International Nuclear Information System (INIS)

Yan Han; Gan Zhiyin; Song Xiaohui; Chen Zhaohui; Xu Jingping; Liu Sheng

2009-01-01

First-principles calculations of magnesium adsorption at the Ga-terminated and N-terminated {0 0 0 1} basal plane wurtzite gallium nitride surfaces have been carried out to explain the atomic-scale insight into the initial adsorption processes of magnesium doping in gallium nitride. The results reveal that magnesium adsorption on N-terminated surfaces is preferred than that on Ga-terminated surfaces. Furthermore, the surface diffusivity of magnesium atom on the N-terminated surface is much lower than that on the Ga-terminated surface, which is due to both the larger average adsorption energies and the lower adsorption distance on N-terminated surface than that on Ga-terminated surface. The results indicate that the p-type doping on the Ga-terminated surface will be better distributed than that on the N-terminated surface.

InGaN/GaN LEDs optical output efficiency enhancement based on AFM surface morphology studies of the constituent layers

Energy Technology Data Exchange (ETDEWEB)

Florescu, D.I.; Ramer, J.C.; Merai, V.N.; Parekh, A.; Lu, D.; Lee, D.S.; Armour, E.A. [Veeco TurboDisc Operations, 394 Elizabeth Avenue, Somerset, NJ 08873 (United States)

2005-05-01

For GaN-based light emitting diodes (LEDs), the growth mechanism and interface roughness of the n-contact, active region, and p-contact layers are of vital importance for achieving superior optical and electrical characteristics of such devices. Nanoscale range surface morphology is one of the key parameters actively employed to developing high optical efficiency applications. In this study, we illustrate the use of atomic force microscopy to investigate and optimise the surface morphology of (a) sapphire substrates and (b) metalorganic chemical vapour deposition (MOCVD) grown InGaN/GaN LED constituent layers (i.e., n-GaN, InGaN active region, and p-GaN). Several optimal cases are presented and discussed, where based on the surface morphology findings an improved selection of (a) substrates and (b) MOCVD growth parameters was achieved leading to an overall enhancement (over 2 times) of the optical output efficiency of these devices. Applying the principles and observations reported, a thermally robust 465 nm multiple quantum well LED with an unpackaged chip-level power output in the 4.0-5.0 mW range and forward voltage <3.2 V at 20 mA was consistently achieved. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Leachability of radioactive constituents from uranium mine tailings

International Nuclear Information System (INIS)

Bryant, D.N.; Cohen, D.B.; Durham, R.W.

1979-04-01

A project was carried out using lysimeters to determine the leaching of radioactive constituents and BaRaSO 4 from abandoned uranium mine tailings. Lime addition to the surface of acidic abandoned tailings did not reduce the level of radioactive constituents in the leachate. Considerable increases in levels of the radionuclides 230 Th, 232 Th and 22 /8Th, as well as gross alpha and beta activity in the leachate, occurred five months after recycling of BaRaSO 4 sediments to the surface layers of abandoned tailings. After nine months of leaching, the levels of 226 Ra in the leachate were 30% greater than the tailings plus sediment treatment than from tailings only (control). Another experiment compared the quality of effluent flowing over chemically-fixed (solidified) BaRaSO 4 sediments with that of non-fixed (control) in simulated sedimentation ponds. During seven months the release of 226 Ra to water from chemically-fixed BaRaSO 4 sediments remained 3 for phosphorus removal) was applied to supply 3 percent organic matter in the top 15 cm of the revegetated lysimeters. Undiluted effluent and leachate from chemically-fixed BaRaSO 4 sediments and fresh tailings were 100 percent lethal to Daphnia pulex and rainbow trout (Salmo gairdneri) in static 96-hour bioassay tests. Diluted (50 percent) effluent samples were non-toxic. (auth)

Calculation of three-dimensional fluid flow with multiple free surfaces

International Nuclear Information System (INIS)

Vander Vorst, M.J.; Chan, R.K.C.

1978-01-01

This paper presents a method for computing incompressible fluid flows with multiple free surfaces which are not restricted in their orientation. The method is presented in the context of the three-dimensional flow in a Mark I reactor pressure suppression system immediately following a postulated loss of coolant accident. The assumption of potential flow is made. The numerical method is a mixed Eulerian-Lagrangian formulation with the interior treated as Eulerian and the free surfaces as Lagrangian. The accuracy of solution hinges on the careful treatment of two important aspects. First, the Laplace equation for the potential is solved at interior points of the Eulerian finite difference mesh using a three-dimensional ''irregular star'' so that boundary conditions can be imposed at the exact position of the free surface. Second, the Lagrangian free surfaces are composed of triangular elements, upon each vertex of which is applied the fully nonlinear Bernoulli equation. One result of these calculations is the transient load on the suppression vessel during the vent clearing and bubble formation events of a loss of coolant accident

Response surfaces and sensitivity analyses for an environmental model of dose calculations

Energy Technology Data Exchange (ETDEWEB)

Iooss, Bertrand [CEA Cadarache, DEN/DER/SESI/LCFR, 13108 Saint Paul lez Durance, Cedex (France)]. E-mail: bertrand.iooss@cea.fr; Van Dorpe, Francois [CEA Cadarache, DEN/DTN/SMTM/LMTE, 13108 Saint Paul lez Durance, Cedex (France); Devictor, Nicolas [CEA Cadarache, DEN/DER/SESI/LCFR, 13108 Saint Paul lez Durance, Cedex (France)

2006-10-15

A parametric sensitivity analysis is carried out on GASCON, a radiological impact software describing the radionuclides transfer to the man following a chronic gas release of a nuclear facility. An effective dose received by age group can thus be calculated according to a specific radionuclide and to the duration of the release. In this study, we are concerned by 18 output variables, each depending of approximately 50 uncertain input parameters. First, the generation of 1000 Monte-Carlo simulations allows us to calculate correlation coefficients between input parameters and output variables, which give a first overview of important factors. Response surfaces are then constructed in polynomial form, and used to predict system responses at reduced computation time cost; this response surface will be very useful for global sensitivity analysis where thousands of runs are required. Using the response surfaces, we calculate the total sensitivity indices of Sobol by the Monte-Carlo method. We demonstrate the application of this method to one site of study and to one reference group near the nuclear research Center of Cadarache (France), for two radionuclides: iodine 129 and uranium 238. It is thus shown that the most influential parameters are all related to the food chain of the goat's milk, in decreasing order of importance: dose coefficient 'effective ingestion', goat's milk ration of the individuals of the reference group, grass ration of the goat, dry deposition velocity and transfer factor to the goat's milk.

A model expansion criterion for treating surface topography in ray path calculations using the eikonal equation

International Nuclear Information System (INIS)

Ma, Ting; Zhang, Zhongjie

2014-01-01

Irregular surface topography has revolutionized how seismic traveltime is calculated and the data are processed. There are two main schemes for dealing with an irregular surface in the seismic first-arrival traveltime calculation: (1) expanding the model and (2) flattening the surface irregularities. In the first scheme, a notional infill medium is added above the surface to expand the physical space into a regular space, as required by the eikonal equation solver. Here, we evaluate the chosen propagation velocity in the infill medium through ray path tracking with the eikonal equation-solved traveltime field, and observe that the ray paths will be physically unrealistic for some values of this propagation velocity. The choice of a suitable propagation velocity in the infill medium is crucial for seismic processing of irregular topography. Our model expansion criterion for dealing with surface topography in the calculation of traveltime and ray paths using the eikonal equation highlights the importance of both the propagation velocity of the infill physical medium and the topography gradient. (paper)

Optimization of simultaneous ultrasonic-assisted extraction of water-soluble and fat-soluble characteristic constituents from Forsythiae Fructus Using response surface methodology and high-performance liquid chromatography.

Science.gov (United States)

Xia, Yong-Gang; Yang, Bing-You; Liang, Jun; Wang, Di; Yang, Qi; Kuang, Hai-Xue

2014-07-01

The compounds (+)-pinoresinol-β-glucoside (1) forsythiaside, (2) phillyrin (3) and phillygenin (4) were elucidated to be the characteristic constituents for quality control of Forsythiae Fructus extract by chromatographic fingerprint in 2010 edition of Chinese Pharmacopoeia due to their numerous important pharmacological actions. It is of great interest to extract these medicinally active constituents from Forsythiae Fructus simultaneously. In this study, a new ultrasound-assisted extraction (UAE) method was developed for the simultaneous extraction of biological components 1-4 in Forsythiae Fructus. The quantitative effects of extraction time, ratio of liquid to solid, extraction temperature, and methanol concentration on yield of these four important biological constituents from Forsythiae Fructus were investigated using response surface methodology with Box-Behnken design. The compounds 1-4 extracted by UAE were quantitative analysis by high-performance liquid chromatography-photodiode array detect (HPLC-PAD), and overall desirability (OD), the geometric mean of the contents of four major biological components, was used as a marker to evaluate the extraction efficiency. By solving the regression equation and analyzing 3-D plots, the optimum condition was at extraction temperature 70°C, time 60 min, ratio of liquid to solid 20, and methanol concentration 76.6%. Under these conditions, extraction yields of compounds 1-4 were 2.92 mg/g, 52.10 mg/g, 0.90 mg/g and 0.57 mg/g, respectively, which were in good agreement with the predicted OD values. In order to achieve a similar yield as UAE, soxhlet extraction required at least 6 h and maceration extraction required much longer time of 24 h. Established UAE method has been successfully applied to sample preparation for the quality control of Forsythiae Fructus. Additionally, a quadrupole time-of-flight mass spectrometry was applied to the structural confirmation of analytes from the complex matrices acquired by UAE

On the calculation of principle curvatures of the left-ventricular surfaces.

Science.gov (United States)

Claus, Piet; Choi, Hon Fai; D'hooge, Jan; Rademakers, Frank E

2008-01-01

A local description of the shape of the left ventricle is relevant in assessing the process of adverse ventricular remodeling, associated with most cardiac pathologies, and in monitoring reverse remodeling by therapy. To quantify local shape of the left ventricle, one can calculate the curvature of its epicardial or endocardial surface. The 3D geometry of the heart and especially the ventricles, can typically be described using finite element meshes. From a mathematical point of view these meshes provide a local parametrization of the surface in the 3-dimensional space. We discuss the analytic derivation of the principle curvatures of the left-ventricular surfaces given their smooth finite-element meshes and apply this derivation to assess the regional shape of the normal porcine left ventricle.

Combining of radionuclides with constituent materials of marine algae

International Nuclear Information System (INIS)

Nakamura, Ryoichi; Nakahara, Motokazu; Ishii, Toshiaki; Ueda, Taishi; Shimizu, Chiaki.

1979-01-01

The relations between the accumulation-elimination of radionuclides and the constituent materials of marine algae were studied to determine more precisely the mechanism of the radioactive contamination of marine organisms. This will increase the information about the behavior of radionuclides in marine organisms in relation to the environmental conditions (temperature, physico-chemical state of radioisotope, and so on) and the biological conditions (feeding habits, species, and so on). Eisenia contaminated by 137 Cs and 106 Ru- 106 Rh was fractionated by solvent extraction into 6 fractions. The largest portion of 137 Cs was in the boiling water fraction; 106 Ru- 106 Rh was most extracted by 24% KOH solution. Elution patterns by Sephadex G-100 gel-filtration of samples differed largely from each other, both among the 3 kinds of radionuclides and between the 2 species of the algae. Therefore, the accumulation of the radionuclides by the marine algae was proved to be not only due to a physical absorption to the surface of the algae but also to the biological combining of the radionuclides with the constituents of the algae. Furthermore, it was found that radionuclides which combine with a few constituents of alga are not eliminated equally. This is considered to be useful for the physiological analysis of elimination curves. (author)

Simulation calculations of physical sputtering and reflection coefficient of plasma-irradiated carbon surface

International Nuclear Information System (INIS)

Kawamura, T.; Ono, T.; Yamamura, Y.

1994-08-01

Physical sputtering yields from the carbon surface irradiated by the boundary plasma are obtained with the use of a Monte Carlo simulation code ACAT. The yields are calculated for many random initial energy and angle values of incident protons or deuterons with a Maxwellian velocity distribution, and then averaged. Here the temperature of the boundary plasma, the sheath potential and the angle δ between the magnetic field line and the surface normal are taken into account. A new fitting formula for an arrangement of the numerical data of sputtering yield is introduced, in which six fitting parameters are determined from the numerical results and listed. These results provide a way to estimate the erosion of carbon materials irradiated by boundary plasma. The particle reflection coefficients for deuterons and their neutrals from a carbon surface are also calculated by the same code and presented together with, for comparison, that for the case of monoenergetic normal incidence. (author)

Constituency Input into Budget Management.

Science.gov (United States)

Miller, Norman E.

1995-01-01

Presents techniques for ensuring constituency involvement in district- and site-level budget management. Outlines four models for securing constituent input and focuses on strategies to orchestrate the more complex model for staff and community participation. Two figures are included. (LMI)

Calculated electronic structure of chromium surfaces and chromium monolayers on iron

International Nuclear Information System (INIS)

Victora, R.H.; Falicov, L.M.

1985-01-01

A self-consistent calculation of the magnetic and electronic properties of the chromium (100) and (110) surfaces and of a chromium monolayer on the (100) and (110) iron surfaces is presented. It is found that (i) the (100) chromium surface is ferromagnetic with a greatly enhanced spin polarization (3.00 electrons); (ii) a substantial enhancement of the spin imbalance exists several (>5) layers into the bulk; (iii) the (110) chromium surface is antiferromagnetic with a large (2.31) spin imbalance; (iv) the (100) chromium monolayer on ferromagnetic iron is ferromagnetic, with a huge spin imbalance (3.63), and aligned antiferromagnetically with respect to the bulk iron; (v) the (110) chromium monolayer on ferromagnetic iron is also ferromagnetic, with a spin imbalance of 2.25 and antiferromagnetically aligned to the iron. The spin imbalance of chromium on iron (100) is possibly the largest of any transition-metal system

Comparison of Dorris-Gray and Schultz methods for the calculation of surface dispersive free energy by inverse gas chromatography.

Science.gov (United States)

Shi, Baoli; Wang, Yue; Jia, Lina

2011-02-11

Inverse gas chromatography (IGC) is an important technique for the characterization of surface properties of solid materials. A standard method of surface characterization is that the surface dispersive free energy of the solid stationary phase is firstly determined by using a series of linear alkane liquids as molecular probes, and then the acid-base parameters are calculated from the dispersive parameters. However, for the calculation of surface dispersive free energy, generally, two different methods are used, which are Dorris-Gray method and Schultz method. In this paper, the results calculated from Dorris-Gray method and Schultz method are compared through calculating their ratio with their basic equations and parameters. It can be concluded that the dispersive parameters calculated with Dorris-Gray method will always be larger than the data calculated with Schultz method. When the measuring temperature increases, the ratio increases large. Compared with the parameters in solvents handbook, it seems that the traditional surface free energy parameters of n-alkanes listed in the papers using Schultz method are not enough accurate, which can be proved with a published IGC experimental result. © 2010 Elsevier B.V. All rights reserved.

Support structure for reactor core constituent element

International Nuclear Information System (INIS)

Aida, Yasuhiko.

1993-01-01

A connection pipe having an entrance nozzle inserted therein as a reactor core constituent element is protruded above the upper surface of a reactor core support plate. A through hole is disposed to the protruding portion of the connection pipe. The through hole and a through hole disposed to the reactor core support plate are connected by a communication pipe. A shear rod is disposed in a horizontal portion at the inside of the communication pipe and is supported by a spring horizontally movably. Further, a groove is disposed at a position of the entrance nozzle opposing to the shear rod. The shear rod is urged out of the communication pipe by the pressure of the high pressure plenum and the top end portion of the shear rod is inserted to the groove of the entrance nozzle during operation. Accordingly, the shear rod is positioned in a state where it is extended from the through hole of the communication pipe to the groove of the entrance nozzle. This can mechanically constrain the rising of the reactor core constituent elements by the shear rod upon occurrence of earthquakes. (I.N.)

Kaon-Nucleon scattering in a constituent quark model

International Nuclear Information System (INIS)

Lemaire, S.

2002-06-01

We have investigated Kaon-Nucleon (KN) interaction in a constituent quark model in the momentum range for the Kaon between 0 and 1 GeV/c in the laboratory frame. This study has been motivated by the fact that in an approach relying on a boson exchange mechanism the Bonn group was forced, in order to obtain good agreement with I = 0 s-wave phase shifts, to add the exchange of a short range fictitious repulsive scalar meson. This need for repulsion, whose range (∼ 0.2 fm) is smaller than the nucleon radius, clearly shows that the quark substructure of the nucleons and K + mesons cannot be neglected. The Kaon-Nucleon phase shifts are calculated in a quark potential model using the resonating group method (RGM). We have to cope with a five body problem with antisymmetrization with respect to the four ordinary quarks of the Kaon-Nucleon system. One requirement of our approach is that the quark-quark interaction must give a quite good description of the hadron spectra. One goal of the present work aims at determining the influence of a relativistic kinematics, in this constituent quark model, for the calculation of KN phase shifts. We have also investigated s, p, d, f, g waves KN elastic phase shifts and we have included a spin-orbit term in the quark-quark interaction. Then we have studied the influence of medium and long range exchange mechanism in the quark quark interaction on KN phase shifts. (author)

The FLUFF code for calculating finned surface heat transfer -description and user's guide

International Nuclear Information System (INIS)

Fry, C.J.

1985-08-01

FLUFF is a computer code for calculating heat transfer from finned surfaces by convection and radiation. It can also represent heat transfer by radiation to a partially emitting and absorbing medium within the fin cavity. The FLUFF code is useful not only for studying the behaviour of finned surfaces but also for deriving heat fluxes which can be applied as boundary conditions to other heat transfer codes. In this way models of bodies with finned surfaces may be greatly simplified since the fins need not be explicitly represented. (author)

Self-consistent Green’s-function technique for bulk and surface impurity calculations: Surface core-level shifts by complete screening

DEFF Research Database (Denmark)

Aldén, M.; Abrikosov, I. A.; Johansson, B.

1994-01-01

of the frozen-core and atomic-sphere approximation but, in addition, includes the dipole contribution to the intersphere potential. Within the concept of complete screening, we identify the surface core-level binding-energy shift with the surface segregation energy of a core-ionized atom and use the Green......'s-function impurity technique in a comprehensive study of the surface core-level shifts (SCLS) of the 4d and 5d transition metals. In those cases, where observed data refer to single crystals, we obtain good agreement with experiment, whereas the calculations typically underestimate the measured shift obtained from...

Dose distribution calculation for in-vivo X-ray fluorescence scanning

International Nuclear Information System (INIS)

Figueroa, R. G.; Lozano, E.; Valente, M.

2013-01-01

In-vivo X-ray fluorescence constitutes a useful and accurate technique, worldwide established for constituent elementary distribution assessment. Actually, concentration distributions of arbitrary user-selected elements can be achieved along sample surface with the aim of identifying and simultaneously quantifying every constituent element. The method is based on the use of a collimated X-ray beam reaching the sample. However, one common drawback for considering the application of this technique for routine clinical examinations was the lack of information about associated dose delivery. This work presents a complete study of the dose distribution resulting from an in-vivo X-ray fluorescence scanning for quantifying biohazard materials on human hands. Absorbed dose has been estimated by means of dosimetric models specifically developed to this aim. In addition, complete dose distributions have been obtained by means of full radiation transport calculations in based on stochastic Monte Carlo techniques. A dedicated subroutine has been developed using the Penelope 2008 main code also integrated with dedicated programs -Mat Lab supported- for 3 dimensional dose distribution visualization. The obtained results show very good agreement between approximate analytical models and full descriptions by means of Monte Carlo simulations. (Author)

First Principles Calculations of Oxygen Adsorption on the UN(001) Surface

International Nuclear Information System (INIS)

Zhukovskii, Yuri F.; Bocharov, Dmitry; Kotomin, Eugene Alexej; Evarestov, Robert; Bandura, A.V.

2009-01-01

Fabrication, handling and disposal of nuclear fuel materials require comprehensive knowledge of their surface morphology and reactivity. Due to unavoidable contact with air components (even at low partial pressures), UN samples contain considerable amount of oxygen impurities affecting fuel properties. In this study we focus on reactivity of the energetically most stable (001) substrate of uranium nitride towards the atomic oxygen as one of initial stages for further UN oxidation. The basic properties of O atoms adsorbed on the UN(001) surface are simulated here combining the two first principles calculation methods based on the plane wave basis set and that of the localized orbitals.

Aims and accomplishments of surface theory

International Nuclear Information System (INIS)

Feibelman, P.J.

1979-01-01

The goals of surface science include the understanding of surface structure, transport and chemistry. However, present activities are mainly focussed on the most basic problem, viz., what are the constituents of a given surface and where are they located. Theorists are approaching this surface characterization problem from two sides. To make better use of the data available from the many experimental surface probes, an understanding of the force laws which govern the motion of probe-particles near surfaces is being developed, and the relation between the excitation and ground state spectra of a solid are being studied. In order to develop a predictive capability regarding surface structure, a variety of intrinsic surface properties are being studied, including the nature of bonds at transition metal surfaces, the meaning of bond locality in extended systems, and the electronic factors underlying the forces which govern surface geometry. These studies often raise technical issues such as the validity of using local exchange-correlation potentials and the applicability of cluster calculations to the analysis of extended surface situations, which, however, should not obscure the main thrust of current work - empirical and predictive surface structure determination. These points are illustrated with examples from recent research and ways in which experimental surface work might assist theoretical efforts are indicated

Calculation of the flux density of gamma rays above the surface of Venus and the Earth

International Nuclear Information System (INIS)

Surkov, Yu.A.; Manvelyan, O.S.

1987-01-01

In this article the authors present the results of calculating the flux density of unscattered gamma rays as a function of height above the surfaces of Venus and the Earth. At each height they calculate the areas which will collect a certain fraction of the gamma rays. The authors calculate the spectra of scattered gamma rays, as well as their integrated fluxes at various heights above the surface of Venus. They consider how the atmosphere will affect the recording of gamma rays. Their results enable them to evaluate the optimal conditions for measuring the gamma-ray fields above the surfaces of Venus and the Earth and to determine the area of the planet which can be investigated in this way. These results are also necessary if they are to determine the elemental composition of the rock from the characteristic recorded spectrum of gamma radiation

Aqueous photochemical degradation of hydroxylated PAHs: Kinetics, pathways, and multivariate effects of main water constituents

Energy Technology Data Exchange (ETDEWEB)

Ge, Linke; Na, Guangshui [Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, Dalian 116023 (China); Chen, Chang-Er [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Li, Jun [Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, Dalian 116023 (China); College of Marine Science, Shanghai Ocean University, Shanghai 201306 (China); Ju, Maowei; Wang, Ying; Li, Kai [Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, Dalian 116023 (China); Zhang, Peng, E-mail: pzhang@nmemc.org.cn [Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, Dalian 116023 (China); Yao, Ziwei [Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, Dalian 116023 (China)

2016-03-15

Hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) are contaminants of emerging concern in the aquatic environment, so it is of great significance to understand their environmental transformation and toxicity. This study investigated the aqueous photochemical behavior of four OH-PAHs, 9-Hydroxyfluorene (9-OHFL), 2-Hydroxyfluorene, 9-Hydroxyphenanthrene and 1-Hydroxypyrene, under simulated sunlight irradiation (λ > 290 nm). It was observed that their photodegradation followed the pseudo-first-order kinetics. Based on the determined quantum yields, their calculated solar apparent photodegradation half-lives in surface waters at 45° N latitude ranged from 0.4 min for 9-Hydroxyphenanthrene to 7.5 × 10{sup 3} min for 9-OHFL, indicating that the OH-PAHs would intrinsically photodegrade fast in sunlit surface waters. Furthermore, 9-OHFL as an example was found to undergo direct photolysis, and self-sensitized photooxidation via ·OH rather than {sup 1}O{sub 2} in pure water. The potential photoreactions involved photoinduced hydroxylation, dehydrogenation and isomerization based on product identification by GC–MS/MS. 9-OHFL photodegraded slower in natural waters than in pure water, which was attributed to the integrative effects of the most photoreactive species, such as Fe(III), NO{sub 3}{sup −}, Cl{sup −} and humic acid. The photomodified toxicity was further examined using Vibrio fischeri, and it was found that the toxicity of photolyzed 9-OHFL did not decrease significantly (p > 0.05) either in pure water or in seawater, implying the comparable or higher toxicity of some intermediates. These results are important for assessing the fate and risks of OH-PAHs in surface waters. - Graphical abstract: Aqueous photochemical behavior of 4 hydroxylated PAHs is first reported on revealing the kinetics, mechanisms, toxicity, and multivariate effects of water constituents. - Highlights: • It is first reported on aqueous photochemical behavior of 4 hydroxylated

Optimization of simultaneous ultrasonic-assisted extraction of water-soluble and fat-soluble characteristic constituents from Forsythiae Fructus Using response surface methodology and high-performance liquid chromatography

Science.gov (United States)

Xia, Yong-Gang; Yang, Bing-You; Liang, Jun; Wang, Di; Yang, Qi; Kuang, Hai-Xue

2014-01-01

Background: The compounds (+)-pinoresinol-β-glucoside (1) forsythiaside, (2) phillyrin (3) and phillygenin (4) were elucidated to be the characteristic constituents for quality control of Forsythiae Fructus extract by chromatographic fingerprint in 2010 edition of Chinese Pharmacopoeia due to their numerous important pharmacological actions. It is of great interest to extract these medicinally active constituents from Forsythiae Fructus simultaneously. Materials and Methods: In this study, a new ultrasound-assisted extraction (UAE) method was developed for the simultaneous extraction of biological components 1-4 in Forsythiae Fructus. The quantitative effects of extraction time, ratio of liquid to solid, extraction temperature, and methanol concentration on yield of these four important biological constituents from Forsythiae Fructus were investigated using response surface methodology with Box-Behnken design. The compounds 1-4 extracted by UAE were quantitative analysis by high-performance liquid chromatography-photodiode array detect (HPLC-PAD), and overall desirability (OD), the geometric mean of the contents of four major biological components, was used as a marker to evaluate the extraction efficiency. Results: By solving the regression equation and analyzing 3-D plots, the optimum condition was at extraction temperature 70°C, time 60 min, ratio of liquid to solid 20, and methanol concentration 76.6%. Under these conditions, extraction yields of compounds 1-4 were 2.92 mg/g, 52.10 mg/g, 0.90 mg/g and 0.57 mg/g, respectively, which were in good agreement with the predicted OD values. In order to achieve a similar yield as UAE, soxhlet extraction required at least 6 h and maceration extraction required much longer time of 24 h. Established UAE method has been successfully applied to sample preparation for the quality control of Forsythiae Fructus. Additionally, a quadrupole time-of-flight mass spectrometry was applied to the structural confirmation of analytes

Transverse energy distribution and hard constituent scattering in hadronic collisions

Directory of Open Access Journals (Sweden)

Torsten Åkesson

1983-01-01

Full Text Available We estimate the contributions to the total transverse energy spectrum from hard constituent scattering and the soft hadronic spectrum in hadron collisions. The transverse energy at which jet production starts to dominate is found to be essentially independent of the cms-energy (for large enough s and roughly a linear function of rapidity and azimuthal angle interval included. Calculations are presented for pp collisions at s= 25and60GeV, andp¯p interactions at s= 540GeV.

X-Ray Fluorescence Determination of the Surface Density of Chromium Nanolayers

Science.gov (United States)

Mashin, N. I.; Chernjaeva, E. A.; Tumanova, A. N.; Ershov, A. A.

2014-01-01

An auxiliary system consisting of thin-film layers of chromium deposited on a polymer film substrate is used to construct calibration curves for the relative intensities of the K α lines of chromium on bulk substrates of different elements as functions of the chromium surface density in the reference samples. Correction coefficients are calculated to take into account the absorption of primary radiation from an x-ray tube and analytical lines of the constituent elements of the substrate. A method is developed for determining the surface density of thin films of chromium when test and calibration samples are deposited on substrates of different materials.

Calculated dose factors for the radiosensitive tissues in bone irradiated by surface-deposited radionuclides

International Nuclear Information System (INIS)

Spiers, F.W.; Whitwell, J.R.; Beddoe, A.H.

1978-01-01

The method of calculating dose factors for the haemopoietic marrow and endosteal tissues in human trabecular bone, used by Whitwell and Spiers for volume-seeking radionuclides, has been developed for the case of radionuclides which are deposited as very thin layers on bone surfaces. The Monte Carlo method is again used, but modifications to the computer program are made to allow for a surface rather than a volume source of particle emission. The principal change is the introduction of a surface-orientation factor which is shown to have a value of approximately 2, varying slightly with bone structure. Results are given for β-emitting radionuclides ranging from 171 Tm(anti Esub(β) = 0.025 MeV) to 90 Y(anti Esub(β) = 0.93 MeV), and also for the α-emitter 239 Pu. It is shown that where the particle ranges are short compared with the dimensions of the bone structures the dose factors for the surface seekers are much greater than those for the volume seekers. For long range particles the dose factors for surface- and volume-seeking radionuclides converge. Comparisons are given relating the dose factors calculated in this paper on the basis of measured bone structures to those of other workers based on single plane geometry. (author)

On the calculation of the free surface temperature of gas-tungsten-arc weld pools from first principles

International Nuclear Information System (INIS)

Choo, R.T.C.; Szekely, J.; David, S.A.

1992-01-01

By combining a mathematical model of the welding arc and of the weld pool, calculations are presented here to describe the free surface temperature of weld pools for spot welding operations. The novel aspects of the treatment include the calculation of the heat and current fluxes falling on the free weld pool surface from first principles, a realistic allowance for heat losses due to vaporization, and a realistic allowance for the temperature dependence of the surface tension. The most important finding reported in this article is that the free surface temperature of weld pools appears to be limited by Marangoni convection, rather than heat losses due to vaporization. Furthermore, it was found that once thermocapillary flow can produce high enough surface velocities (>25 cm/s), the precise nature of the relationship between temperature and surface tension will become less important

Anti-inflammatory and bronchodilatory constituents of leaf extracts of Anacardium occidentale L. in animal models.

Science.gov (United States)

Awakan, Oluwakemi Josephine; Malomo, Sylvia Omonirume; Adejare, Abdullahi Adeyinka; Igunnu, Adedoyin; Atolani, Olubunmi; Adebayo, Abiodun Humphrey; Owoyele, Bamidele Victor

2018-01-01

Anacardium occidentale L. leaf is useful in the treatment of inflammation and asthma, but the bioactive constituents responsible for these activities have not been characterized. Therefore, this study was aimed at identifying the bioactive constituent(s) of A. occidentale ethanolic leaf extract (AOEL) and its solvent-soluble portions, and evaluating their effects on histamine-induced paw edema and bronchoconstriction. The bronchodilatory effect was determined by measuring the percentage protection provided by plant extracts in the histamine-induced bronchoconstriction model in guinea pigs. The anti-inflammatory effect of the extracts on histamine-induced paw edema in rats was determined by measuring the increase in paw diameter, after which the percent edema inhibition was calculated. The extracts were analyzed using gas chromatography-mass spectrometry to identify the bioactive constituents. Column chromatography and Fourier transform infrared spectroscopy were used respectively to isolate and characterize the constituents. The bronchodilatory and anti-inflammatory activities of the isolated bioactive constituent were evaluated. Histamine induced bronchoconstriction in the guinea pigs and edema in the rat paw. AOEL, hexane-soluble portion of AOEL, ethyl acetate-soluble portion of AOEL, and chloroform-soluble portion of AOEL significantly increased bronchodilatory and anti-inflammatory activities (P 9-octadecenamide) was identified as the most abundant compound in the extracts and was isolated. Oleamide significantly increased bronchodilatory and anti-inflammatory activities by 32.97% and 98.41%, respectively (P < 0.05). These results indicate that oleamide is one of the bioactive constituents responsible for the bronchodilatory and anti-inflammatory activity of A. occidentale leaf, and can therefore be employed in the management of bronchoconstriction and inflammation. Copyright © 2017 Shanghai Changhai Hospital. Published by Elsevier B.V. All rights

Calculation of acoustic field based on laser-measured vibration velocities on ultrasonic transducer surface

Science.gov (United States)

Hu, Liang; Zhao, Nannan; Gao, Zhijian; Mao, Kai; Chen, Wenyu; Fu, Xin

2018-05-01

Determination of the distribution of a generated acoustic field is valuable for studying ultrasonic transducers, including providing the guidance for transducer design and the basis for analyzing their performance, etc. A method calculating the acoustic field based on laser-measured vibration velocities on the ultrasonic transducer surface is proposed in this paper. Without knowing the inner structure of the transducer, the acoustic field outside it can be calculated by solving the governing partial differential equation (PDE) of the field based on the specified boundary conditions (BCs). In our study, the BC on the transducer surface, i.e. the distribution of the vibration velocity on the surface, is accurately determined by laser scanning measurement of discrete points and follows a data fitting computation. In addition, to ensure the calculation accuracy for the whole field even in an inhomogeneous medium, a finite element method is used to solve the governing PDE based on the mixed BCs, including the discretely measured velocity data and other specified BCs. The method is firstly validated on numerical piezoelectric transducer models. The acoustic pressure distributions generated by a transducer operating in an homogeneous and inhomogeneous medium, respectively, are both calculated by the proposed method and compared with the results from other existing methods. Then, the method is further experimentally validated with two actual ultrasonic transducers used for flow measurement in our lab. The amplitude change of the output voltage signal from the receiver transducer due to changing the relative position of the two transducers is calculated by the proposed method and compared with the experimental data. This method can also provide the basis for complex multi-physical coupling computations where the effect of the acoustic field should be taken into account.

Constituent concentrations, loads, and yields to Beaver Lake, Arkansas, water years 1999-2008

Science.gov (United States)

Bolyard, Susan E.; De Lanois, Jeanne L.; Green, W. Reed

2010-01-01

Beaver Lake is a large, deep-storage reservoir used as a drinking-water supply and considered a primary watershed of concern in the State of Arkansas. As such, information is needed to assess water quality, especially nutrient enrichment, nutrient-algal relations, turbidity, and sediment issues within the reservoir system. Water-quality samples were collected at three main inflows to Beaver Lake: the White River near Fayetteville, Richland Creek at Goshen, and War Eagle Creek near Hindsville. Water-quality samples collected over the period represented different flow conditions (from low to high). Constituent concentrations, flow-weighted concentrations, loads, and yields from White River, Richland Creek, and War Eagle Creek to Beaver Lake for water years 1999-2008 were documented for this report. Constituents include total ammonia plus organic nitrogen, dissolved nitrite plus nitrate nitrogen, dissolved orthophosphorus (soluble reactive phosphorus), total phosphorus, total nitrogen, dissolved organic carbon, total organic carbon, and suspended sediment. Linear regression models developed by computer program S-LOADEST were used to estimate loads for each constituent for the 10-year period at each station. Constituent yields and flow-weighted concentrations for each of the three stations were calculated for the study. Constituent concentrations and loads and yields varied with time and varied among the three tributaries contributing to Beaver Lake. These differences can result from differences in precipitation, land use, contributions of nutrients from point sources, and variations in basin size. Load and yield estimates varied yearly during the study period, water years 1999-2008, with the least nutrient and sediment load and yields generally occurring in water year 2006, and the greatest occurring in water year 2008, during a year with record amounts of precipitation. Flow-weighted concentrations of most constituents were greatest at War Eagle Creek near Hindsville

Effect of micrometric hot spots on surface temperature measurement and flux calculation in the middle and long infrared

International Nuclear Information System (INIS)

Delchambre, E; Counsell, G; Kirk, A

2009-01-01

The non-uniformity of the target temperature due to micrometric hot spots (Hermann et al 2004 Phys. Scr. T 111 98) is an explanation for the experimental fact that near-infrared measurements yield higher temperature values than mid-infrared measurements (Hildebrandt et al 2003 InfraMation 2003 Proc. (Las Vegas, USA, October 2003), Delchambre et al 2005 J. Nucl. Mater. 337-339 1069). The issue of micrometric hot spot disturbance in the surface temperature (T surf ) measurement and heat load calculation is addressed in this paper. The theoretical investigation at 3, 5 and 12 μm and experiments in the range 3.5-5 μm indicate that the surface state can play an important role in the non-uniform heating surface and consequently in the overestimation of the bulk temperature. The contribution of the hot spots to temperature measurements and flux calculations has been simulated at different wavelengths. Calculations show that (1) the overestimation of the bulk temperature decreases with the wavelength and (2) the overestimation depends on the temperature difference, ΔT, between the bulk and the micrometric hot spots. In addition, experiments have been carried out in order to compare the flux calculations at different wavelengths on different graphite (polished, dusty). The results obtained are very sensitive to the surface state pointing out the difficulties in improving the heat flux calculation model, since the surface state can change during the plasma discharges. This paper shows that the problem of non-homogenous surface temperature can be significantly diminished on working at longer wavelengths.

Resinous constituent extracting process

Energy Technology Data Exchange (ETDEWEB)

Sayer, W F

1947-10-07

The method of recovering oily constituents from coal or oil shale comprising the saturation of coal or oil shale in a sealed vessel with an organic solution having a boiling point at atmospheric pressure of not exceeding 220/sup 0/C, elevating the temperature within the vessel to a temperature below the cracking temperature of the constituents and maintaining the pressure within the vessel below 51 pounds, to extract the oily material from the coal or oil shale and subsequently separating the solvent from the oily material.

Theoretical Calculations of the Seasonal and Solar Activity Variations for Ionospheric Collision Frequency and Debye Length over Baghdad City

Directory of Open Access Journals (Sweden)

Ali Hussein Ni'ma

2017-03-01

Full Text Available In this study, two important ionospheric factors have been calculated, the collision frequency of electron and Deby length for a height range from 80 Km to a height approaching the maximum height of the F2 region of the ionosphere above the Earth's surface. Both above factors have been calculated for two different levels of solar activity and for two seasons (winter and summer. Also, six months were adopted for every level of solar activity and season. The estimation of collision frequency of electron is depends on the contribution of neutral constituents and ions. Three neutral atmospheric gases have been adopted to calculate the collision frequency, Molecular and atomic oxygen O2 and O respectively and molecular nitrogen N2, as well as the singly charged ions were taken into account in calculation.

Aquatic photochemistry of sulfamethazine: multivariate effects of main water constituents and mechanisms.

Science.gov (United States)

Li, Yingjie; Liu, Xiangliang; Zhang, Biaojun; Zhao, Qun; Ning, Ping; Tian, Senlin

2018-03-01

The ubiquity of sulfonamides (SAs) in natural waters requires insight into their environmental fate for ecological risk assessment. Extensive studies focused on the effect of univariate water constituents on the photochemical fate of SAs, yet the multivariate effects of water constituents in environmentally relevant concentrations on SA photodegradation are poorly understood. Here, response surface methodology was employed to explore the integrative effects of main water constituents (dissolved organic matter (DOM), NO 3 - , HCO 3 - , Cu 2+ ) on the photodegradation of a representative SA (sulfamethazine). Results showed that besides single factors, interaction of factors also significantly impacted the photodegradation. Radical scavenging experiments indicated that triplet-excited DOM ( 3 DOM*) was responsible for the enhancing effect of DOM on the photodegradation. Additionally, DOM may also quench the 3 DOM*-mediated oxidation intermediate of sulfamethazine causing the inhibiting effect of DOM-DOM interaction. We also found that HCO 3 - was oxidized by triplet-excited sulfamethazine producing CO 3 ˙ - , and the high reactivity of CO 3 ˙ - with sulfamethazine (second-order rate constant 2.2 × 10 8 M -1 s -1 ) determined by laser flash photolysis revealed the enhancing photodegradation mechanism of HCO 3 - . This study is among the first attempts to probe the photodegradation of SAs considering the integrative effects of water constituents, which is important in accurate ecological risk assessment of organic pollutants in the aquatic environment.

SLOWNESS SURFACE CALCULATION FOR DIFFERENT MEDIA USING THE SYMBOLIC MATHEMATICS LANGUAGE MAPLE®

Directory of Open Access Journals (Sweden)

Piedrahita Carlos

2004-06-01

Full Text Available Starting from the equation in different media, we obtain the different type of waves that can exists in such media. The evaluation of the eigenvalues and eigenvectors let us construct the slowness surfaces. In general complex calculations case have to be made. In this work, routines were implemented in the symbolic language MAPLE® and the slowness surfaces were plotted. This work is relevant for the modelling of equivalent media that simulates natural fractured reservoirs, like those common in the Colombian foothills. It is important to understand the seismic response of this reservoirs for exploration of this areas.

Electromagnetic splitting for mesons and baryons using dressed constituent quarks

International Nuclear Information System (INIS)

Silvestre-Brac, Bernard; Brau, Fabian; Semay, Claude

2003-01-01

Electromagnetic splittings for mesons and baryons are calculated in a formalism where the constituent quarks are considered as dressed quasiparticles. The electromagnetic interaction, which contains coulomb, contact and hyperfine terms, is folded with the quark electrical density. Two different types of strong potentials are considered. Numerical treatment is done very carefully and several approximations are discussed in detail. Our model contains only one free parameter and the agreement with experimental data is reasonable although it seems very difficult to obtain a perfect description in any case

FreeSASA: An open source C library for solvent accessible surface area calculations.

Science.gov (United States)

Mitternacht, Simon

2016-01-01

Calculating solvent accessible surface areas (SASA) is a run-of-the-mill calculation in structural biology. Although there are many programs available for this calculation, there are no free-standing, open-source tools designed for easy tool-chain integration. FreeSASA is an open source C library for SASA calculations that provides both command-line and Python interfaces in addition to its C API. The library implements both Lee and Richards' and Shrake and Rupley's approximations, and is highly configurable to allow the user to control molecular parameters, accuracy and output granularity. It only depends on standard C libraries and should therefore be easy to compile and install on any platform. The library is well-documented, stable and efficient. The command-line interface can easily replace closed source legacy programs, with comparable or better accuracy and speed, and with some added functionality.

Three-body calculation of Be double-hypernuclei

Indian Academy of Sciences (India)

Energy levels and bond energy of the double- hypernucleus are calculated by considering two- and three-cluster interactions. Interactions between constituent particles are contact interactions for reproducing the low binding energy of nuclei. The effective action is constructed to involve three-body forces. In this paper ...

Detection analysis of surface hydroxyl active sites and simulation calculation of the surface dissociation constants of aqueous diatomite suspensions

Science.gov (United States)

Ma, Shu-Cui; Wang, Zhi-Gang; Zhang, Ji-Lin; Sun, De-Hui; Liu, Gui-Xia

2015-02-01

The surface properties of the diatomite were investigated using nitrogen adsorption/deadsorption isotherms, TG-DSC, FTIR, and XPS, and surface protonation-deprotonation behavior was determined by continuous acid-base potentiometric titration technique. The diatomite sample with porous honeycomb structure has a BET specific surface area of 10.21 m2/g and large numbers of surface hydroxyl functional groups (i.e. tbnd Si-OH, tbnd Fe-OH, and tbnd Al-OH). These surface hydroxyls can be protonated or deprotonated depending on the pH of the suspension. The experimental potentiometric data in two different ionic strength solutions (0.1 and 0.05 mol/L NaCl) were fitted using ProtoFit GUI V2.1 program by applying diffuse double layer model (DLM) with three amphoteric sites and minimizing the sum of squares between a dataset derivative function and a model derivative function. The optimized surface parameters (i.e. surface dissociation constants (log K1, log K2) and surface site concentrations (log C)) of the sample were obtained. Based on the optimized surface parameters, the surface species distribution was calculated using Program-free PHREEQC 3.1.2. Thus, this work reveals considerable new information about surface protonation-deprotonation processes and surface adsorptive behaviors of the diatomite, which helps us to effectively use the cheap and cheerful diatomite clay adsorbent.

Analysis of gamma irradiated pepper constituents, 1

International Nuclear Information System (INIS)

Takagi, Kazuko; Okuyama, Tsuneo

1988-01-01

A reversed phase high performance liquid chromatographic (HPLC) method was developed for the analysis of many constituents of pepper at the same time. And a extraction method of ultraviolet absorbing constituents from pepper was developed for the HPLC analysis. The Ultraviolet absorbing constituents were extracted by precooled Automatic Air-Hammer from frozen pepper with 20% acetonitrile in water. The process of extraction was achieved under cooling by liquid nitrogen from start to end. The extracted constituents were separated on a reversed phase C 8 (LiChrospher 300 RP - 8 10 μm 0.4 I.D. x 0.4 cm and LiChrosorb RP - 8 SelectB 0.4 I. D. x 25 cm) column with a concave gradient from 0.1% trifluoro acetic acid (TFA) in water to 75% acetonitrile and 0.1% TFA in water for 60 minutes. The eluted constituents were detected 210 nm and 280 nm. The present method permits the detection of about 50 peaks by 280 nm. (author)

Robust and efficient handling of yield surface discontinuities in elasto-plastic finite element calculations

DEFF Research Database (Denmark)

Clausen, Johan Christian; Damkilde, Lars; Andersen, Lars Vabbersgaard

2015-01-01

Purpose – The purpose of this paper is to present several methods on how to deal with yield surface discontinuities. The explicit formulations, first presented by Koiter (1953), result in multisingular constitutive matrices which can cause numerical problems in elasto-plastic finite element...... documented in the literature all present “easy” calculation examples, e.g. low friction angles and few elements. The amendments presented in this paper result in robust elasto-plastic computations, making the solution of “hard” problems possible without introducing approximations in the yield surfaces...... calculations. These problems, however, are not documented in previous literature. In this paper an amendment to the Koiter formulation of the constitutive matrices for stress points located on discontinuities is proposed. Design/methodology/approach – First, a review of existing methods of handling yield...

Calculation of parameter failure probability of thermodynamic system by response surface and importance sampling method

International Nuclear Information System (INIS)

Shang Yanlong; Cai Qi; Chen Lisheng; Zhang Yangwei

2012-01-01

In this paper, the combined method of response surface and importance sampling was applied for calculation of parameter failure probability of the thermodynamic system. The mathematics model was present for the parameter failure of physics process in the thermodynamic system, by which the combination arithmetic model of response surface and importance sampling was established, then the performance degradation model of the components and the simulation process of parameter failure in the physics process of thermodynamic system were also present. The parameter failure probability of the purification water system in nuclear reactor was obtained by the combination method. The results show that the combination method is an effective method for the calculation of the parameter failure probability of the thermodynamic system with high dimensionality and non-linear characteristics, because of the satisfactory precision with less computing time than the direct sampling method and the drawbacks of response surface method. (authors)

CHEMICAL INVESTIGATION OF THE VOLATILE CONSTITUENTS ...

African Journals Online (AJOL)

CHEMICAL INVESTIGATION OF THE VOLATILE CONSTITUENTS OF CLEOME VISCOSA FROM NIGERIA. Gabriel Olatunji, Peter Weyerstahl, Stephen Oguntoye. Abstract. The major volatile constituents of the oils from the integral parts of Cleome viscosa L. from Nigeria have been identified by GC, GC/MS and 1H NMR.

Calculated Fermi surface properties of LaSn3 and YSn3 under pressure

International Nuclear Information System (INIS)

Kanchana, V.

2012-01-01

The electronic structure, Fermi surface and elastic properties of the iso-structural and iso-electronic LaSn 3 and YSn 3 intermetallic compounds are studied under pressure within the frame work of density functional theory including spin-orbit coupling. The LaSn 3 Fermi surface consists of two sheets, of which the second is very complex. Under pressure a third sheet appears around compression V/V 0 =0.94, while a small topology changes in the second sheet is seen at compression V/V 0 =0.90. This may be in accordance with the anomalous behavior in the superconducting transition temperature observed in LaSn 3 , which has been suggested to reflect a Fermi surface topological transition, along with a non-monotonic pressure dependence of the density of states at the Fermi level. The similar behavior is not observed in YSn 3 for which the Fermi surface includes three sheets already at ambient conditions, and the topology remains unchanged under pressure. The reason for the difference in behavior between LaSn 3 and YSn 3 is the role of spin-orbit coupling and the hybridization of La-4f state with the Sn-p state in the vicinity of the Fermi level, which is well explained using the band structure calculation. The elastic constants and related mechanical properties are calculated at ambient as well as at elevated pressures. The elastic constants increase with pressure for both compounds and satisfy the conditions for mechanical stability under pressure. (author)

Using Neural Networks to Improve the Performance of Radiative Transfer Modeling Used for Geometry Dependent Surface Lambertian-Equivalent Reflectivity Calculations

Science.gov (United States)

Fasnacht, Zachary; Qin, Wenhan; Haffner, David P.; Loyola, Diego; Joiner, Joanna; Krotkov, Nickolay; Vasilkov, Alexander; Spurr, Robert

2017-01-01

Surface Lambertian-equivalent reflectivity (LER) is important for trace gas retrievals in the direct calculation of cloud fractions and indirect calculation of the air mass factor. Current trace gas retrievals use climatological surface LER's. Surface properties that impact the bidirectional reflectance distribution function (BRDF) as well as varying satellite viewing geometry can be important for retrieval of trace gases. Geometry Dependent LER (GLER) captures these effects with its calculation of sun normalized radiances (I/F) and can be used in current LER algorithms (Vasilkov et al. 2016). Pixel by pixel radiative transfer calculations are computationally expensive for large datasets. Modern satellite missions such as the Tropospheric Monitoring Instrument (TROPOMI) produce very large datasets as they take measurements at much higher spatial and spectral resolutions. Look up table (LUT) interpolation improves the speed of radiative transfer calculations but complexity increases for non-linear functions. Neural networks perform fast calculations and can accurately predict both non-linear and linear functions with little effort.

Adsorption of organic molecules on mineral surfaces studied by first-principle calculations: A review.

Science.gov (United States)

Zhao, Hongxia; Yang, Yong; Shu, Xin; Wang, Yanwei; Ran, Qianping

2018-04-09

First-principle calculations, especially by the density functional theory (DFT) methods, are becoming a power technique to study molecular structure and properties of organic/inorganic interfaces. This review introduces some recent examples on the study of adsorption models of organic molecules or oligomers on mineral surfaces and interfacial properties obtained from first-principles calculations. The aim of this contribution is to inspire scientists to benefit from first-principle calculations and to apply the similar strategies when studying and tailoring interfacial properties at the atomistic scale, especially for those interested in the design and development of new molecules and new products. Copyright © 2017. Published by Elsevier B.V.

Inorganic Constituents in Coal

Directory of Open Access Journals (Sweden)

Rađenović A.

2006-02-01

Full Text Available Coal contains not only organic matter but also small amounts of inorganic constituents. More thanone hundred different minerals and virtually every element in the periodic table have been foundin coal. Commonly found group minerals in coal are: major (quartz, pyrite, clays and carbonates,minor, and trace minerals. Coal includes a lot of elements of low mass fraction of the orderof w=0.01 or 0.001 %. They are trace elements connected with organic matter or minerals comprisedin coal. The fractions of trace elements usually decrease when the rank of coal increases.Fractions of the inorganic elements are different, depending on the coal bed and basin. A varietyof analytical methods and techniques can be used to determine the mass fractions, mode ofoccurrence, and distribution of organic constituents in coal. There are many different instrumentalmethods for analysis of coal and coal products but atomic absorption spectroscopy – AAS is theone most commonly used. Fraction and mode of occurrence are one of the main factors that haveinfluence on transformation and separation of inorganic constituents during coal conversion.Coal, as an important world energy source and component for non-fuels usage, will be continuouslyand widely used in the future due to its relatively abundant reserves. However, there is aconflict between the requirements for increased use of coal on the one hand and less pollution onthe other. It’s known that the environmental impacts, due to either coal mining or coal usage, canbe: air, water and land pollution. Although, minor components, inorganic constituents can exert asignificant influence on the economic value, utilization, and environmental impact of the coal.

Calculation of Operations Efficiency Factors for Mars Surface Missions

Science.gov (United States)

Layback, Sharon L.

2014-01-01

enough time to capture variations in relay asset interactions, Earth/Mars time phasing, and seasonal variations in holidays). This model is used to estimate the ops efficiency factor for each operations configuration. The second model in a separate Excel spreadsheet is a scenario model, which uses the sol types to rack up the total number of "scenario sols" for that scenario (in other words, the ideal number of sols it would take to perform the scenario objectives). Then, the number of sols requiring ground in the loop is calculated based on the soil types contained in the given scenario. Next, the scenario contains a description of what sequence of operations configurations is used, for how many days each, and this is used with the corresponding ops efficiency factors for each configuration to calculate the "ops duration" corresponding to that scenario. Finally, a margin is applied to determine the minimum surface lifetime required for that scenario. Typically, this level of analysis has not been performed until much later in the mission, and has not been able to influence mission design. Further, the notion of moving to sustainable operations during Prime Mission - and the effect that that move would have on surface mission productivity and mission objective choices - has not been encountered until the most recent rover missions (MSL and Mars 2018).

Deformed baryons: constituent quark model vs. bag model

International Nuclear Information System (INIS)

Iwamura, Y.; Nogami, Y.

1985-01-01

Recently Bhaduri et al. developed a nonrelativistic constituent quark model for deformed baryons. In that model the quarks move in a deformable mean field, and the deformation parameters are determined by minimizing the quark energy subject to the constraint of volume conservation. This constraint is an ad hoc assumption. It is shown that, starting with a bag model, a model similar to that of Bhaduri et al. can be constructed. The deformation parameters are determined by the pressure balance on the bag surface. There is, however, a distinct difference between the two models with respect to the state dependence of the ''volume''. Implications of this difference are discussed

Handbook for the calculation of reactor protections; Formulaire sur le calcul de la protection des reacteurs

Energy Technology Data Exchange (ETDEWEB)

NONE

1963-07-01

This note constitutes the first edition of a Handbook for the calculation of reactor protections. This handbook makes it possible to calculate simply the different neutron and gamma fluxes and consequently, to fix the minimum quantities of materials necessary under general safety conditions both for the personnel and for the installations. It contains a certain amount of nuclear data, calculation methods, and constants corresponding to the present state of our knowledge. (authors) [French] Cette note constitue la premiere edition du 'Formulaire sur le calcul de la protection des reacteurs'. Ce formulaire permet de calculer de facon simple les difterents flux de neutrons et de gamma et, par suite, de fixer les quantites minima de materiaux a utiliser pour que les conditions generales de securite soient respectees, tant pour le personnel que pour les installations. Il contient un certain nombre de donnees nucleaires, de methodes de calcul et de constantes correspondant a l'etat actuel de nos connaissances. (auteurs)

Density Functional Calculation of the 0.5ML-Terminated Allyl Mercaptan/Si(100)-(2 × 1) Surface

International Nuclear Information System (INIS)

Chun-Mei, Tang; Kai-Ming, Deng; Xuan, Chen; Chuan-Yun, Xiao; Yu-Zhen, Liu; Qun-Xiang, Li

2009-01-01

The structural and electronic properties of the 0.5 ML-terminated allyl mercaptan (ALM)/Si(100)-(2 × 1) surface are studied using the density functional method. The calculated absorption energy of the ALM molecule on the 0.5 ML-terminated ALM/Si(100)-(2 × 1) surface is 3.36 eV, implying that adsorption is strongly favorable. The electronic structure calculations show that the ALM/Si(100)-(2 × 1), the clean Si(100)-(2 × 1), and the fully-terminated H/Si(100)-(2 × 1) surfaces have the nature of an indirect band gap semiconductor. The highest occupied molecular orbital is dominated by the ALM, confirming the mechanism proposed by Hossain for its chain reaction. (condensed matter: structure, mechanical and thermal properties)

He atom scattering from ZnO surfaces: calculation of diffraction peak intensities using the close-coupling approach

Energy Technology Data Exchange (ETDEWEB)

MartInez-Casado, R [Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ (United Kingdom); Miret-Artes, S [Instituto de Fisica Fundamental, Consejo Superior de Investigaciones CientIficas, Serrano 123, 28006 Madrid (Spain); Meyer, B [Interdisziplinaeres Zentrum fuer Molekulare Materialien ICMM and Computer-Chemie-Centrum CCC, Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Naegelsbachstrasse 25, 91052 Erlangen (Germany); Traeger, F [Lehrstuhl fuer Physikalische Chemie I, Ruhr-Universitaet Bochum, 44801 Bochum (Germany); Woell, Ch, E-mail: r.martinezcasado@imperial.ac.u [Institut fuer Funktionelle Grenzflaechen, Karlsruher Institut fuer Technologie KIT, Kaiserstrasse 12, 76131 Karlsruhe (Germany)

2010-08-04

Diffraction intensities of a molecular He beam scattered off the clean and water-covered ZnO(101-bar0) surface have been simulated using a new potential model in conjunction with the close-coupling formalism. The effective corrugation functions for the systems He-ZnO(101-bar0) and He-H{sub 2}O/ZnO(101-bar0) have been obtained from density functional theory calculations within the Esbjerg-Noerskov approximation. Using these data a potential model is constructed consisting of a corrugated Morse potential at small He-surface distances and a semiempiric attractive part at larger distances. The diffraction patterns obtained from close-coupling calculations agree with the experimental data within about 10%, which opens the possibility to simulate He diffraction from surfaces of any structural complexity and to verify surface and adsorbate structures proposed theoretically by employing this kind of analysis.

A finite-density calculation of the surface tension of isotropic-nematic interfaces

International Nuclear Information System (INIS)

Moore, B.G.; McMullen, W.E.

1992-01-01

The surface tension of the isotropic-nematic interface in a fluid of intermediate-sized hard particles is studied and calculated. The transition from isotropic to nematic is fixed to occur in a continuous fashion by varying the biaxiality of the model particles. A reversal in the preferred orientation of the bulk nematic relative to the isotropic-nematic interface suggests an oblique orientation of the bulk nematic. 32 refs., 8 figs

ASYMPTOTICAL CALCULATION OF ELECTROMAGNETIC WAVES SCATTERED FROM A DIELECTRIC COATED CYLINDRICAL SURFACE WITH PHYSICAL OPTICS APPROACH

Directory of Open Access Journals (Sweden)

Uğur YALÇIN

2004-02-01

Full Text Available In this study, quasi-optical scattering of finite source electromagnetic waves from a dielectric coated cylindrical surface is analysed with Physical Optics (PO approach. A linear electrical current source is chosen as the finite source. Reflection coefficient of the cylindrical surface is derived by using Geometrical Theory of Diffraction (GTD. Then, with the help of this coefficient, fields scattered from the surface are obtained. These field expressions are used in PO approach and surface scattering integral is determined. Evaluating this integral asymptotically, fields reflected from the surface and surface divergence coefficient are calculated. Finally, results obtained in this study are evaluated numerically and effects of the surface impedance to scattered fields are analysed. The time factor is taken as j te? in this study.

Temporal trends in water-quality constituent concentrations and annual loads of chemical constituents in Michigan watersheds, 1998–2013

Science.gov (United States)

Hoard, Christopher J.; Fogarty, Lisa R.; Duris, Joseph W.

2018-02-21

In 1998, the Michigan Department of Environmental Quality and the U.S. Geological Survey began the Water Chemistry Monitoring Program for select streams in the State of Michigan. Objectives of this program were to provide assistance with (1) statewide water-quality assessments, (2) the National Pollutant Discharge Elimination System permitting process, and (3) water-resource management decisions. As part of this program, water-quality data collected from 1998 to 2013 were analyzed to identify potential trends for select constituents that were sampled. Sixteen water-quality constituents were analyzed at 32 stations throughout Michigan. Trend analysis on the various water-quality data was done using either the uncensored Seasonal Kendall test or through Tobit regression. In total, 79 trends were detected in the constituents analyzed for 32 river stations sampled for the study period—53 downward trends and 26 upward trends were detected. The most prevalent trend detected throughout the State was for ammonia, with 11 downward trends and 1 upward trend estimated.In addition to trends, constituent loads were estimated for 31 stations from 2002 to 2013 for stations that were sampled 12 times per year. Loads were computed using the Autobeale load computation program, which used the Beale ratio estimator approach to estimate an annual load. Constituent loads were the largest in large watershed streams with the highest annual flows such as the Saginaw and Grand Rivers. Likewise, constituent loads were the smallest in smaller tributaries that were sampled as part of this program such as the Boardman and Thunder Bay Rivers.

An evaluation of calculation parameters in the EGSnrc/BEAMnrc Monte Carlo codes and their effect on surface dose calculation

International Nuclear Information System (INIS)

Kim, Jung-Ha; Hill, Robin; Kuncic, Zdenka

2012-01-01

The Monte Carlo (MC) method has proven invaluable for radiation transport simulations to accurately determine radiation doses and is widely considered a reliable computational measure that can substitute a physical experiment where direct measurements are not possible or feasible. In the EGSnrc/BEAMnrc MC codes, there are several user-specified parameters and customized transport algorithms, which may affect the calculation results. In order to fully utilize the MC methods available in these codes, it is essential to understand all these options and to use them appropriately. In this study, the effects of the electron transport algorithms in EGSnrc/BEAMnrc, which are often a trade-off between calculation accuracy and efficiency, were investigated in the buildup region of a homogeneous water phantom and also in a heterogeneous phantom using the DOSRZnrc user code. The algorithms and parameters investigated include: boundary crossing algorithm (BCA), skin depth, electron step algorithm (ESA), global electron cutoff energy (ECUT) and electron production cutoff energy (AE). The variations in calculated buildup doses were found to be larger than 10% for different user-specified transport parameters. We found that using BCA = EXACT gave the best results in terms of accuracy and efficiency in calculating buildup doses using DOSRZnrc. In addition, using the ESA = PRESTA-I option was found to be the best way of reducing the total calculation time without losing accuracy in the results at high energies (few keV ∼ MeV). We also found that although choosing a higher ECUT/AE value in the beam modelling can dramatically improve computation efficiency, there is a significant trade-off in surface dose uncertainty. Our study demonstrates that a careful choice of user-specified transport parameters is required when conducting similar MC calculations. (note)

Preliminary Investigation on the Phytochemical Constituents of ...

African Journals Online (AJOL)

Demand for honey consumption nowadays is continuously increasing worldwide due to its multiple importance from food to medicine. The medicinal value of honey lies in the bioactive phytochemical constituents that produce health benefits to man. Investigation of the phytochemical constituents of the two honey samples ...

Density functional studies: First principles and semiempirical calculations of clusters and surfaces

International Nuclear Information System (INIS)

Sinnott, S.B.

1993-01-01

In the research presented here, various theoretical electronic structure techniques are utilized to analyze widely different systems from silicon clusters to transition metal solids and surfaces. For the silicon clusters, first principles density functional methods are used to investigate Si N for N = 2-8. The goal is to understand the different types of bonding that can occur in such small clusters where the coordination of the atoms differs substantially from that of the stable bulk tetrahedral bonding. Such uncoordinated structures can provide a good test of more approximate theories that can be used eventually to model silicon surfaces, of obvious technological importance. For the transition metal systems, non-self-consistent electronic structure methods are used to provide an understanding of the driving force for surface relaxations. An in-depth analysis of the results is presented and the physical basis of surface relaxation within the theory is discussed. In addition, the limitations inherent in calculations of metal surface relaxation are addressed. Finally, in an effort to increase understanding of approximate methods, a novel non-self-consistent density functional electronic structure method is developed that is ∼1000 times faster computationally than more sophisticated methods. This new method is tested for a variety of systems including diatomics, mixed clusters, surfaces and bulk lattices. The strengths and weaknesses of the new theory are discussed in detail, leading to greater understanding of non-self-consistent density functional theories as a whole

Manual for calculating critical loads of heavy metals for soils and surface waters; preliminary guidelines for environmental quality criteria, calculation methods and input data

NARCIS (Netherlands)

Vries, de W.; Bakker, D.J.

1996-01-01

Methodologies are described for calculating critical loads of lead, cadmium, copper, zinc, nickel, chromium and mercury for soils and surface waters. The aspects which are discussed are: selection of a computation model, determination of environmental-quality criteria for the metals, collection of

Effects of interfering constituents on tritium smears

International Nuclear Information System (INIS)

Levi, G.D. Jr.; Cheeks, K.E.

1993-01-01

Tritium smears are performed by Health Protection Operations (HPO) to assess transferable contamination on work place surfaces, materials for movement outside Radiologically Controlled Areas (RCA), and product containers being shipped between facilities. Historically, gas proportional counters were used to detect transferable tritium contamination collected by smearing. Because tritium is a low-energy beta emitter, gas proportional counters do not provide the sensitivity or the counting efficiency to accurately measure the tritium activity on the smear. Liquid Scintillation Counters (LSC) provide greater counting efficiency for the low-energy beta particles along with greater reliability and reproducibility compared to gas flow proportional counters. The purpose of this technical evaluation was to determine the effects of interfering constituents such as filters, dirt and oil on the counting efficiency and tritium recoveries of tritium smears by LSC

Inhibition and inactivation of Salmonella typhimurium biofilms from polystyrene and stainless steel surfaces by essential oils and phenolic constituent carvacrol.

Science.gov (United States)

Soni, Kamlesh A; Oladunjoye, Ademola; Nannapaneni, Ramakrishna; Schilling, M Wes; Silva, Juan L; Mikel, Benjy; Bailey, R Hartford

2013-02-01

Persistence of Salmonella biofilms within food processing environments is an important source of Salmonella contamination in the food chain. In this study, essential oils of thyme and oregano and their antimicrobial phenolic constituent carvacrol were evaluated for their ability to inhibit biofilm formation and inactivate preformed Salmonella biofilms. A crystal violet staining assay and CFU measurements were utilized to quantify biofilm cell mass, with evaluating factors such as strain variation, essential oil type, their concentrations, exposure time, as well as biofilm formation surface. Of the three Salmonella strains, Salmonella Typhimurium ATCC 23564 and Salmonella Typhimurium ATCC 19585 produced stronger biofilms than Salmonella Typhimurium ATCC 14028. Biofilm formation by different Salmonella strains was 1.5- to 2-fold higher at 22°C than at 30 or 37°C. The presence of nonbiocidal concentrations of thyme oil, oregano oil, and phenolic carvacrol at 0.006 to 0.012% suppressed Salmonella spp. biofilm formation 2- to 4-fold, but could not completely eliminate biofilm formation. There was high correlation in terms of biofilm inactivation, as determined by the crystal violet-stained optical density (at a 562-nm wavelength) readings and the viable CFU counts. Reduction of biofilm cell mass was dependent on antimicrobial concentration. A minimum concentration of 0.05 to 0.1% of these antimicrobial agents was needed to reduce a 7-log CFU biofilm mass to a nondetectable level on both polystyrene and stainless steel surfaces within 1 h of exposure time.

Effects of the cellulose, xylan and lignin constituents on biomass pyrolysis characteristics and bio-oil composition using the Simplex Lattice Mixture Design method

International Nuclear Information System (INIS)

Fan, Yongsheng; Cai, Yixi; Li, Xiaohua; Jiao, Lihua; Xia, Jisheng; Deng, Xiuli

2017-01-01

Highlights: • Simplex Lattice Mixture Design was firstly applied to study biomass pyrolysis process. • Interactions between the constituents had effects on the biomass pyrolysis behavior. • Biomass pyrolysis behavior can be predicted based on the ratios of three constituents. • Bio-oil composition was affected by the constituents and their pyrolysis products. - Abstract: In order to clarify the relationships between biomass pyrolysis mechanism and its main constituents. The effects of main constituents on biomass pyrolysis characteristics were firstly determined by thermo-gravimetric analysis based on the Simplex Lattice Mixture Design to investigate that whether the prediction of the pyrolysis behavior of a certain lignocellulosic biomass is possible when its main constituent contents are known. The results showed that there are constituent interactions in the pyrolysis process, which can be intuitively reflected through the change laws of kinetics parameters. The mathematical models for calculating kinetics values were established, and the models were proved to be valid for predicting lignocellulosic biomass pyrolysis behavior. In addition, the effects of biomass constituents on bio-oil compositions were explored by subsequent vacuum pyrolysis experiments. The xylan pyrolysis had a certain inhibitory effect on the pyrolysis of cellulose, and the pyrolysis products of lignin might promote the further decomposition of sugars from cellulose pyrolysis, while the interaction between xylan and lignin had a little effect on the bio-oil composition.

Transformation of potential energy surfaces for estimating isotopic shifts in anharmonic vibrational frequency calculations

Energy Technology Data Exchange (ETDEWEB)

Meier, Patrick; Oschetzki, Dominik; Rauhut, Guntram, E-mail: rauhut@theochem.uni-stuttgart.de [Institut für Theoretische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart (Germany); Berger, Robert [Clemens-Schöpf Institut für Organische Chemie and Biochemie, Technische Universität Darmstadt, Petersenstrasse 22, 64287 Darmstadt (Germany)

2014-05-14

A transformation of potential energy surfaces (PES) being represented by multi-mode expansions is introduced, which allows for the calculation of anharmonic vibrational spectra of any isotopologue from a single PES. This simplifies the analysis of infrared spectra due to significant CPU-time savings. An investigation of remaining deviations due to truncations and the so-called multi-level approximation is provided. The importance of vibrational-rotational couplings for small molecules is discussed in detail. In addition, an analysis is proposed, which provides information about the quality of the transformation prior to its execution. Benchmark calculations are provided for a set of small molecules.

First-principles study of the surface properties of U-Mo system

Energy Technology Data Exchange (ETDEWEB)

Mei, Zhi-Gang; Liang, Linyun; Yacout, Abdellatif M.

2018-02-01

U-Mo alloys are promising fuels for future high-performance research reactors with low enriched uranium. Surface properties, such as surface energy, are important inputs for mesoscale simulations (e.g., phase field method) of fission gas bubble behaviors in irradiated nuclear fuels. The lack of surface energies of U-Mo alloys prevents an accurate modeling of the morphology of gas bubbles and gas bubble-induced fuel swelling. To this end, we study the surface properties of U-Mo system, including bcc Mo, alpha-U, gamma-U, and gamma U-Mo alloys. All surfaces up to a maximum Miller index of three and two are calculated for cubic Mo and gamma-U and non-cubic alpha-U, respectively. The equilibrium crystal shapes of bcc Mo, alpha-U and gamma-U are constructed using the calculated surface energies. The dominant surface orientations and the area fraction of each facet are determined from the constructed equilibrium crystal shape. The disordered gamma U-Mo alloys are simulated using the Special Quasirandom Structure method. The (1 1 0) and (1 0 0) surface energies of gamma U-7Mo and U-10Mo alloys are predicted to lie between those of gamma-U and bcc Mo, following a linear combination of the two constituents' surface energies. To better compare with future measurements of surface energies, the area fraction weighted surface energies of alpha-U, gamma-U and gamma U-7Mo and U-10Mo alloys are also predicted. (C) 2017 Published by Elsevier B.V.

A risk assessment approach to identifying constituents in oilfield produced water for treatment prior to beneficial use.

Science.gov (United States)

Horner, Jennifer E; Castle, James W; Rodgers, John H

2011-05-01

A risk assessment approach incorporating exposure pathways and calculated risk quotients was applied to identifying constituents requiring treatment prior to beneficial use of oilfield produced water (OPW). In this study, risk quotients are ratios of constituent concentrations in soil or water to guideline concentrations for no adverse effects to receptors. The risk assessment approach is illustrated by an example of an oilfield water produced from non-marine geologic strata of a rift basin in sub-Saharan Africa. The OPW studied has the following characteristics: 704-1370 mg L(-1) total dissolved solids (TDS), 45-48 mg L(-1) chloride, and 103.8 mg L(-1) oil and grease. Exposure pathways of constituents in OPW used for irrigation include: ingestion of plant tissue, ingestion and direct contact of irrigated soil by livestock, inhalation of aerosols or volatilized constituents, and ingestion of OPW directly by livestock. Applying risk quotient methods for constituents in soil and water, constituents of concern (COCs) identified for irrigation and livestock watering using the OPW studied include: iron (Fe), manganese (Mn), nickel (Ni), zinc (Zn), and oil and grease. Approximately 165,000 barrels d(-1) (26,233 m(3) d(-1)) of OPW from the study site are available for use. Identification of COCs and consideration of water quantity allows for development of reliable treatment design criteria to ensure effective and consistent treatment is achieved to meet guideline levels required for irrigation, livestock watering, or other uses. This study illustrates the utility of risk assessment for identifying the COCs in OPW for treatment, the level of treatment required, and viable options for use of the treated water. Copyright © 2011 Elsevier Inc. All rights reserved.

Volatile constituents of commercial imported and domestic black-ripe table olives (Olea europaea).

Science.gov (United States)

Sansone-Land, Angelina; Takeoka, Gary R; Shoemaker, Charles F

2014-04-15

Volatile constituents of commercial black-ripe table olives (Olea europaea) from the United States, Spain, Egypt and Morocco were analysed by gas chromatography and gas chromatography-mass spectrometry (GC-MS). Dynamic headspace sampling was used to isolate a variety of aldehydes, alcohols, esters, ketones, phenols, terpenes, norisoprenoids, and pyridines. Odour unit values, calculated from concentration and odour threshold data, indicate that the following compounds are major contributors to black-ripe table olive aroma: β-damascenone, nonanal, (E)-dec-2-enal, 3-methylbutanal, ethyl benzoate, octanal, 2-methoxyphenol, 2-methylbutanal and 2-methoxy-4-methylphenol. Imported olives contained a variety of fermentation derived volatiles that were not detected in domestic olives. Constituents such as ethyl 2-methylbutanoate, ethyl 3-methylbutanoate, 3-methylbutyl acetate, oct-1-en-3-one, ethyl hexanoate, (Z)-hex-3-enyl acetate, hexyl acetate, ethyl cyclohexanecarboxylate, benzyl acetate and 4-ethylphenol contributed to the odour of imported olives but were not detected in domestic olives. Published by Elsevier Ltd.

Calculating the Maximum Density of the Surface Packing of Ions in Ionic Liquids

Science.gov (United States)

Kislenko, S. A.; Moroz, Yu. O.; Karu, K.; Ivaništšev, V. B.; Fedorov, M. V.

2018-05-01

The maximum density of monolayer packing on a graphene surface is calculated by means of molecular dynamics (MD) for ions of characteristic size and symmetry: 1-butyl-3-methylimidazolium [BMIM]+, tetrabutylammonium [TBA]+, tetrafluoroborate [BF4]-, dicyanamide [DCA]-, and bis(trifluoromethane) sulfonimide [TFSI]-. The characteristic orientations of ions in a closely packed monolayer are found. It is shown that the formation of a closely packed monolayer is possible for [DCA]- and [BF4]- anions only at surface charges that exceed the limit of the electrochemical stability of the corresponding ionic liquids. For the [TBA]+ cation, a monolayer structure can be observed at the charge of nearly 30 μC/cm2 attainable in electrochemical experiment.

Spectroscopic characterization of cell membranes and their constituents of the plant-associated soil bacterium Azospirillum brasilense

Science.gov (United States)

Kamnev, A. A.; Antonyuk, L. P.; Matora, L. Yu.; Serebrennikova, O. B.; Sumaroka, M. V.; Colina, M.; Renou-Gonnord, M.-F.; Ignatov, V. V.

1999-05-01

Structural and compositional features of bacterial membranes and some of their isolated constituents (cell surface lipopolysaccharide, phospholipids) of the plant-growth-promoting diazotrophic rhizobacterium Azospirillum brasilense (wild-type strain Sp245) were characterized using Fourier transform infrared (FTIR) spectroscopy and some other techniques. FTIR spectra of the cell membranes were shown to comprise the main vibration modes of the relevant lipopolysaccharide and protein components which are believed to be involved in associative plant-bacterium interactions, as well as of phospholipid constituents. The role and functions of metal cations in the structural organization and physicochemical properties of bacterial cell membranes are also discussed considering their accumulation in the membranes from the culture medium.

Effects of time pressure and accountability to constituents on negotiation

NARCIS (Netherlands)

Mosterd, I.; Rutte, C.G.

2000-01-01

A laboratory experiment examined the effects of time pressure (high versus low) and accountability to constituents (not-accountable-to-constituents versus accountable-to-constituents) on the competitiveness of negotiators' interaction and on the outcome (i.e., agreement or impasse) of the

Nucleon form factors at high q2 within constituent quark models

International Nuclear Information System (INIS)

Desplanques, B.; Silvestre-Brac, B.; Cano, F.; Noguera, S.; Gonzalez, P.; .

2000-01-01

The nucleon form factors are calculated using a non-relativistic description in terms of constituent quarks. The emphasis is put on present numerical methods used to solve the three-body problem in order to reliably predict the expected asymptotic behavior of form factors. Nucleon wave functions obtained in the hyperspherical formalism or employing Faddeev equations have been considered. While a q -8 behavior is expected at high q for a quark-quark force behaving like 1/r at short distances, it is found that the hyper central approximation in the hyperspherical formalism (K = 0) leads to a q -7 behavior. An infinite set of waves would be required to get the correct behavior. Solutions of the Faddeev equations lead to the q -8 behavior. The coefficient of the corresponding term, however, depends on the number of partial waves retained in the Faddeev amplitude. The convergence to the asymptotic behavior has also been studied. Approximate expressions characterizing this one have been derived. From the comparison with the most complete Faddeev calculation, a validity range is inferred for restricted calculations. Refs. 46 (author)

[Chemical constituents in Buddleja albiflora].

Science.gov (United States)

Tao, Liang; Huang, Jincheng; Zhao, Yanping; Li, Chong

2009-12-01

To study the chemical constituents of Buddleja albiflora. The constituents were isolated by column chromatography and their structures were elucidated by spectroscopic methods. Eleven compounds were isolated and identified as luteolin (1), quercetin (2), quercetin-3-O-beta-D-glucopyranoside (3), apigenin (4), apigenin-7-O-beta-D-glucopyranoside (5), apigenin-7-O-neohesperidoside (6), acacetin-7-O-beta-L-rhamnopyranosyl-(1-6)-beta-D-glucopyranoside (7), cranioside A (8), acetylmartynoside B (9), 4"-O-acetylmartynoside (10), isomartynoside (11). All these compounds were obtained from B. albiflora for the first time and compound 8 was obtained from the genus Buddleja for the first time.

Calculation of reasonable exemption levels for surface contamination by measuring overall gamma ray

International Nuclear Information System (INIS)

Ogino, Haruyuki; Hattori, Takatoshi

2008-01-01

The present regulation on surface contamination [Bq/cm 2 ] is determined from a simple radiological model for the most hazardous radionuclides (Pu-239 for alpha emitters and Sr-90 for beta emitters) and its extremely conservative model is applied for all other alpha and beta emitters. In this study, reasonable exemption levels for surface contamination are calculated for each radionuclide by adopting an original radiological dose evaluation method for surface contamination that can be applied in radiation safety, transport safety and waste safety. Furthermore, a new concept of judging the exemption by estimating the overall contamination [Bq] on the objects from the measurement of gamma ray has been designed and a reasonable value was derived. We conclude that the overall exemption levels obtained by gamma ray measurement can be one order smaller than those obtained by the conventional method for some radionuclides, such as Mn-54, Co-60, Nb-94, Cs-134, Cs-137, Eu-152 and Eu-154. (author)

Analysis of constituents of earth formations

International Nuclear Information System (INIS)

Hertzog, R.C.; Grau, J.A.

1981-01-01

The composition of an earth formation is investigated by repetitively irradiating the formation with bursts of neutrons from a source and measuring an energy spectrum of the scattering gamma rays resulting from such irradiation e.g. by photomultiplier or solid state detector. The measured spectrum is thereafter analyzed by comparing it with a composite spectrum, made up of standard spectra, measured in a controlled environment, of constituents postulated to comprise the formation. As a result of such analysis, the proportions of the postulated constituents in the formation are determined. Since the measured spectrum is subject to degradation due to changes in the resolution of the detector, a filtering arrangement effects modification of the standard spectra in a manner which compensates for the changes in the detector and thereby provides for a more accurate determination of the constituents of the formation. Temperature is measured by sensor to compensate for temperature dependence of detector resolution. (author)

Constituents of Chondria armata

Digital Repository Service at National Institute of Oceanography (India)

Govenkar, M.B.; Wahidullah, S.

A novel long chain fatty ester, pentyl hentriacontanoate 1 and an orange red pigment, caulerpin 2 have been isolated and characterised from a red alga Chondria armata. The pigment caulerpin hitherto known to be a constituent of green algae of genus...

A simple method for calculation of Glauber's amplitude

International Nuclear Information System (INIS)

Omboo, Z.

1983-01-01

A method of calculating the terms of Glauber series expansions for elastic scattering of composed systems are presented. The inclusion of general scattering diagram simplifies essentially the calculation procedure. In this case the complicated combinatorical problem of reduction of similar terms in Glauber series is solved easily and determinant corresponding to various terms of the series decreases at least by a factor of two, if numbers of constituents of scattered systems are equal. If these numbers are not equal, the determinant order is equal to the smallest one

Collective probabilities algorithm for surface hopping calculations

International Nuclear Information System (INIS)

Bastida, Adolfo; Cruz, Carlos; Zuniga, Jose; Requena, Alberto

2003-01-01

General equations that transition probabilities of the hopping algorithms in surface hopping calculations must obey to assure the equality between the average quantum and classical populations are derived. These equations are solved for two particular cases. In the first it is assumed that probabilities are the same for all trajectories and that the number of hops is kept to a minimum. These assumptions specify the collective probabilities (CP) algorithm, for which the transition probabilities depend on the average populations for all trajectories. In the second case, the probabilities for each trajectory are supposed to be completely independent of the results from the other trajectories. There is, then, a unique solution of the general equations assuring that the transition probabilities are equal to the quantum population of the target state, which is referred to as the independent probabilities (IP) algorithm. The fewest switches (FS) algorithm developed by Tully is accordingly understood as an approximate hopping algorithm which takes elements from the accurate CP and IP solutions. A numerical test of all these hopping algorithms is carried out for a one-dimensional two-state problem with two avoiding crossings which shows the accuracy and computational efficiency of the collective probabilities algorithm proposed, the limitations of the FS algorithm and the similarity between the results offered by the IP algorithm and those obtained with the Ehrenfest method

In-situ Kd values and geochemical behavior for inorganic and organic constituents of concern at the TNX Outfall Delta

International Nuclear Information System (INIS)

Kaplan, D.I.

2000-01-01

A series of tests were conducted to provide site-specific Kd values for constituents of concern at the TNX Outfall Delta Operable Unit. These Kd values can be used to calculate contaminant migration within the operable unit and are, at this time considered to be the most defensible values

Radiation damage to DNA constituents

International Nuclear Information System (INIS)

Bergene, R.

1977-01-01

The molecular changes of the DNA molecule, in various systems exposed to inoizing radiation, have been the subject of a great number of studies. In the present work electron spin resonance spectroscopy (ESR) has been applied to irradiated crystalline systems, in particular single crystals of DNA subunits and their derivatives. The main conclusions about the molecular damage are based on this technique in combination with molecular orbital calculations. It should be emphasized that the ESR technique is restricted to damage containing unpaired electrons. These unstable intermediates called free radicals seem, however, to be involved in all molecular models describing the action of radiation on DNA. One of the premises for a detailed theory of the radiation induced reactions at the physico-chemical level seems to involve exact knowledge of the induced free radicals as well as the modes of their formation and fate. For DNA, as such, it is hardly possible to arrive at such a level of knowledge since the molecular complexity prevents selective studies of the many different radiation induced products. One possible approach is to study the free radicals formed in the constituents of DNA. In the present work three lines of approach should be mentioned. The first is based on the observation that radical formation in general causes only minor structural alterations to the molecule in question. The use of isotopes with different spin and magnetic moment (in particular deuterium) may also serve a source of information. Deuteration leads to a number of protons, mainly NH - and OH, becoming substituted, and if any of these are involved in interactions with unpaired protons the resonance pattern is influeneed. The third source of information is molecular orbital calculation. The electron spin density distribution is a function in the three dimensional space based on the system's electronic wave functions. This constitutes the basis for the idea that ESR data can be correlated with

Theoretical investigation of lead vapor adsorption on kaolinite surfaces with DFT calculations

Energy Technology Data Exchange (ETDEWEB)

Wang, Xinye [Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096 (China); Huang, Yaji, E-mail: heyyj@seu.edu.cn [Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096 (China); Pan, Zhigang [College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009 (China); Wang, Yongxing; Liu, Changqi [Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096 (China)

2015-09-15

Highlights: • Al surface after dehydroxylation is active while Si surface is inert. • The active sites are the unsaturated Al atoms and O atoms losing H atom. • PbO is the most suitable species for adsorption. • Increasing the activities of Al atoms can enhance the performance of kaolinite. • Produce of amorphous silica is a potential path to enhance the performance of kaolinite. - Abstract: Kaolinite can be used as the in-furnace sorbent/additive to adsorb lead (Pb) vapor at high temperature. In this paper, the adsorptions of Pb atom, PbO molecule and PbCl{sub 2} molecule on kaolinie surfaces were investigated by density functional theory (DFT) calculation. Si surface is inert to Pb vapor adsorption while Al surfaces with dehydroxylation are active for the unsaturated Al atoms and the O atoms losing H atoms. The adsorption energy of PbO is much higher than that of Pb atom and PbCl{sub 2}. Considering the energy barriers, it is easy for PbO and PbCl{sub 2} to adsorb on Al surfaces but difficult to escape. The high energy barriers of de–HCl process cause the difficulties of PbCl{sub 2} to form PbO·Al{sub 2}O{sub 3}·2SiO{sub 2} with kaolinite. Considering the inertia of Si atoms and the activity of Al atoms after dehydroxylation, calcination, acid/alkali treatment and some other treatment aiming at amorphous silica producing and Al activity enhancement can be used as the modification measures to improve the performance of kaolinite as the in-furnace metal capture sorbent.

Electronic and optical properties of titanium nitride bulk and surfaces from first principles calculations

Science.gov (United States)

Mehmood, Faisal; Pachter, Ruth; Murphy, Neil R.; Johnson, Walter E.

2015-11-01

Prediction of the frequency-dependent dielectric function of thin films poses computational challenges, and at the same time experimental characterization by spectroscopic ellipsometry remains difficult to interpret because of changes in stoichiometry and surface morphology, temperature, thickness of the film, or substrate. In this work, we report calculations for titanium nitride (TiN), a promising material for plasmonic applications because of less loss and other practical advantages compared to noble metals. We investigated structural, electronic, and optical properties of stoichiometric bulk TiN, as well as of the TiN(100), TiN(110), and TiN(111) outermost surfaces. Density functional theory (DFT) and many-body GW methods (Green's (G) function-based approximation with screened Coulomb interaction (W)) were used, ranging from G0W0, GW0 to partially self-consistent sc-GW0, as well as the GW-BSE (Bethe-Salpeter equation) and time-dependent DFT (TDDFT) methods for prediction of the optical properties. Structural parameters and the band structure for bulk TiN were shown to be consistent with previous work. Calculated dielectric functions, plasma frequencies, reflectivity, and the electron energy loss spectrum demonstrated consistency with experiment at the GW0-BSE level. Deviations from experimental data are expected due to varying experimental conditions. Comparison of our results to spectroscopic ellipsometry data for realistic nanostructures has shown that although TDDFT may provide a computationally feasible level of theory in evaluation of the dielectric function, application is subject to validation with GW-BSE calculations.

Calculation of high-dimensional fission-fusion potential-energy surfaces in the SHE region

International Nuclear Information System (INIS)

Moeller, Peter; Sierk, Arnold J.; Ichikawa, Takatoshi; Iwamoto, Akira

2004-01-01

We calculate in a macroscopic-microscopic model fission-fusion potential-energy surfaces relevant to the analysis of heavy-ion reactions employed to form heavy-element evaporation residues. We study these multidimensional potential-energy surfaces both inside and outside the touching point.Inside the point of contact we define the potential on a multi-million-point grid in 5D deformation space where elongation, merging projectile and target spheroidal shapes, neck radius and projectile/target mass asymmetry are independent shape variables. The same deformation space and the corresponding potential-energy surface also describe the shape evolution from the nuclear ground-state to separating fragments in fission, and the fast-fission trajectories in incomplete fusion.For separated nuclei we study the macroscopic-microscopic potential energy, that is the ''collision surface'' between a spheroidally deformed target and a spheroidally deformed projectile as a function of three coordinates which are: the relative location of the projectile center-of-mass with respect to the target center-of-mass and the spheroidal deformations of the target and the projectile. We limit our study to the most favorable relative positions of target and projectile, namely that the symmetry axes of the target and projectile are collinear

Constituent-level pile-up mitigation techniques in ATLAS

CERN Document Server

The ATLAS collaboration

2017-01-01

Pile-up of simultaneous proton-proton collisions at the LHC has a significant impact on jet reconstruction. In this note the performance of several pile-up mitigation techniques is evaluated in detailed simulations of the ATLAS experiment. Four algorithms that act on the jet-constituent level are evaluated: SoftKiller, the cluster vertex fraction algorithm and Voronoi and constituent subtraction. We find that application of these constituent-level algorithms improves the resolution of low-transverse-momentum jets. The improvement is significant for collisions with 80-200 simultaneous proton-proton collisions envisaged in future runs of the LHC.

SHORT COMMUNICATION CHEMICAL CONSTITUENTS AND ...

African Journals Online (AJOL)

CHEMICAL CONSTITUENTS AND ANTIOXIDANT ACTIVITIES OF THE FRUITS ... alkaloids, phenols, steroids, flavonoids, saponins and terpenoids while tannin ..... Harveer, K.; Jasmeen, S. Synthesis, characterization and radical scavenging ...

Cinnamomum zeylanicum extract on the radiolabelling of blood constituents and the morphometry of red blood cells: In vitro assay

International Nuclear Information System (INIS)

Benarroz, M.O.; Fonseca, A.S.; Rocha, G.S.; Frydman, J.N.G.; Rocha, V.C.; Pereira, M.O.

2008-01-01

Effects of Cinnamomum zeylanicum (cinnamon) on the labelling of blood constituents with technetium-99 m( 99m Tc) and on the morphology of red blood cells were studied. Blood samples from Wistar rats were incubated with cinnamon extract for 1hour or with 0.9% NaCl, as control. Labelling of blood constituents with 99m Tc was performed. Plasma (P) and blood cells (BC), soluble (SF-P and SF-BC) and insoluble (IF-P and IF-BC) fractions were separated. The radioactivity in each fraction was counted and the percentage of radioactivity incorporated (%ATI) was calculated. Blood smears were prepared, fixed, stained and the qualitative and quantitative morphological analysis of the red blood cells was evaluated. The data showed that the cinnamon extract decreased significantly (p 99m Tc, and although our results were obtained with animals, precaution is suggested in interpretations of nuclear medicine examinations involving the labelling of blood constituents in patients who are using cinnamon

A new approach for calculation of volume confined by ECR surface and its area in ECR ion source

International Nuclear Information System (INIS)

Filippov, A.V.

2007-01-01

The volume confined by the resonance surface and its area are important parameters of the balance equations model for calculation of ion charge-state distribution (CSD) in the electron-cyclotron resonance (ECR) ion source. A new approach for calculation of these parameters is given. This approach allows one to reduce the number of parameters in the balance equations model

How to calculate linear absorption spectra with lifetime broadening using fewest switches surface hopping trajectories: A simple generalization of ground-state Kubo theory

International Nuclear Information System (INIS)

Petit, Andrew S.; Subotnik, Joseph E.

2014-01-01

In this paper, we develop a surface hopping approach for calculating linear absorption spectra using ensembles of classical trajectories propagated on both the ground and excited potential energy surfaces. We demonstrate that our method allows the dipole-dipole correlation function to be determined exactly for the model problem of two shifted, uncoupled harmonic potentials with the same harmonic frequency. For systems where nonadiabatic dynamics and electronic relaxation are present, preliminary results show that our method produces spectra in better agreement with the results of exact quantum dynamics calculations than spectra obtained using the standard ground-state Kubo formalism. As such, our proposed surface hopping approach should find immediate use for modeling condensed phase spectra, especially for expensive calculations using ab initio potential energy surfaces

Ab initio supercell calculations of the (0001) α-Cr2O3 surface with a partially or totally Al-substituted external layer

International Nuclear Information System (INIS)

Sun Jizhong; Stirner, Thomas

2009-01-01

Ab initio supercell calculations employing the periodic Hartree-Fock formalism are presented of the (0001) α-Cr 2 O 3 surface with a partially or totally Al-substituted external layer. In the simulations a fraction of the Cr atoms at the surface of the chromia slab are replaced by Al atoms, and the Al surface coverage is varied between zero (pure chromia) and 100% (Al-terminated chromia). The surface Al atoms are found to relax inwards considerably, with the magnitude of the relaxation decreasing with increasing Al surface coverage. The calculations also reveal that the surface energy of the slab decreases with increasing Al coverage. Finally, the electronic properties at the surface of the Al-substituted (0001) α-Cr 2 O 3 slabs are investigated. Here the calculations show that the substitution of Cr by Al gives rise to an increase in the covalency of the Al-O bonds compared to slabs of pure alumina. In contrast, the influence of the surface Al atoms on the electrostatic potential in the (0001) plane of metal ions is relatively small. These findings support the utilisation of α-chromia substrates for the templated growth of α-alumina, which is consistent with recent experiments.

Potential energy surface, dipole moment surface and the intensity calculations for the 10 μm, 5 μm and 3 μm bands of ozone

Science.gov (United States)

Polyansky, Oleg L.; Zobov, Nikolai F.; Mizus, Irina I.; Kyuberis, Aleksandra A.; Lodi, Lorenzo; Tennyson, Jonathan

2018-05-01

Monitoring ozone concentrations in the Earth's atmosphere using spectroscopic methods is a major activity which undertaken both from the ground and from space. However there are long-running issues of consistency between measurements made at infrared (IR) and ultraviolet (UV) wavelengths. In addition, key O3 IR bands at 10 μm, 5 μm and 3 μm also yield results which differ by a few percent when used for retrievals. These problems stem from the underlying laboratory measurements of the line intensities. Here we use quantum chemical techniques, first principles electronic structure and variational nuclear-motion calculations, to address this problem. A new high-accuracy ab initio dipole moment surface (DMS) is computed. Several spectroscopically-determined potential energy surfaces (PESs) are constructed by fitting to empirical energy levels in the region below 7000 cm-1 starting from an ab initio PES. Nuclear motion calculations using these new surfaces allow the unambiguous determination of the intensities of 10 μm band transitions, and the computation of the intensities of 10 μm and 5 μm bands within their experimental error. A decrease in intensities within the 3 μm is predicted which appears consistent with atmospheric retrievals. The PES and DMS form a suitable starting point both for the computation of comprehensive ozone line lists and for future calculations of electronic transition intensities.

Calculating infrared contributions to vacuum expectation values of gluonic and quark fields

International Nuclear Information System (INIS)

Arbuzov, B.A.; Boos, E.E.; Turashvili, K.Sh.

1986-01-01

Based on the infrared asymptotics of the lower QCD Green's functions obtained before, we propose a definition and elaborate a technique for calculating non-perturbative vacuum expectations of gluon and quark fields. In our calculations, we use only the known QCD parameters: constituent quark masses, the confining potential slope and the QCD parameter Λ. The values obtained for the vacuum expectations agree well with experiment. (orig.)

Adsorption and structure of water on kaolinite surfaces: possible insight into ice nucleation from grand canonical monte carlo calculations.

Science.gov (United States)

Croteau, T; Bertram, A K; Patey, G N

2008-10-30

Grand canonical Monte Carlo calculations are used to determine water adsorption and structure on defect-free kaolinite surfaces as a function of relative humidity at 235 K. This information is then used to gain insight into ice nucleation on kaolinite surfaces. Results for both the SPC/E and TIP5P-E water models are compared and demonstrate that the Al-surface [(001) plane] and both protonated and unprotonated edges [(100) plane] strongly adsorb at atmospherically relevant relative humidities. Adsorption on the Al-surface exhibits properties of a first-order process with evidence of collective behavior, whereas adsorption on the edges is essentially continuous and appears dominated by strong water lattice interactions. For the protonated and unprotonated edges no structure that matches hexagonal ice is observed. For the Al-surface some of the water molecules formed hexagonal rings. However, the a o lattice parameter for these rings is significantly different from the corresponding constant for hexagonal ice ( Ih). A misfit strain of 14.0% is calculated between the hexagonal pattern of water adsorbed on the Al-surface and the basal plane of ice Ih. Hence, the ring structures that form on the Al-surface are not expected to be good building-blocks for ice nucleation due to the large misfit strain.

[Study on the chemical constituents of Buddleja purdomii].

Science.gov (United States)

Zhang, Yinghua; Li, Chong; Zhang, Chengzhong; Tao, Baoquan

2005-11-01

To study the chemical constituents of Buddleja purdomii W. W Smith. The constituents were isolated and purified by various chromatographic methods and structurally identified by spectral analysis. 4 compounds were obtained as cryptomeridiol (I), aucubin (II), galactilol (III), daucosterol (IV). All these compounds are obtained from this plant for the first time.

Electronic and optical properties of titanium nitride bulk and surfaces from first principles calculations

International Nuclear Information System (INIS)

Mehmood, Faisal; Pachter, Ruth; Murphy, Neil R.; Johnson, Walter E.

2015-01-01

Prediction of the frequency-dependent dielectric function of thin films poses computational challenges, and at the same time experimental characterization by spectroscopic ellipsometry remains difficult to interpret because of changes in stoichiometry and surface morphology, temperature, thickness of the film, or substrate. In this work, we report calculations for titanium nitride (TiN), a promising material for plasmonic applications because of less loss and other practical advantages compared to noble metals. We investigated structural, electronic, and optical properties of stoichiometric bulk TiN, as well as of the TiN(100), TiN(110), and TiN(111) outermost surfaces. Density functional theory (DFT) and many-body GW methods (Green's (G) function-based approximation with screened Coulomb interaction (W)) were used, ranging from G 0 W 0 , GW 0 to partially self-consistent sc-GW 0 , as well as the GW-BSE (Bethe-Salpeter equation) and time-dependent DFT (TDDFT) methods for prediction of the optical properties. Structural parameters and the band structure for bulk TiN were shown to be consistent with previous work. Calculated dielectric functions, plasma frequencies, reflectivity, and the electron energy loss spectrum demonstrated consistency with experiment at the GW 0 -BSE level. Deviations from experimental data are expected due to varying experimental conditions. Comparison of our results to spectroscopic ellipsometry data for realistic nanostructures has shown that although TDDFT may provide a computationally feasible level of theory in evaluation of the dielectric function, application is subject to validation with GW-BSE calculations

Calculation of electrical potentials on the surface of a realistic head model by finite differences

International Nuclear Information System (INIS)

Lemieux, L.; McBride, A.; Hand, J.W.

1996-01-01

We present a method for the calculation of electrical potentials at the surface of realistic head models from a point dipole generator based on a 3D finite-difference algorithm. The model was validated by comparing calculated values with those obtained algebraically for a three-shell spherical model. For a 1.25 mm cubic grid size, the mean error was 4.9% for a superficial dipole (3.75 mm from the inner surface of the skull) pointing in the radial direction. The effect of generator discretization and node spacing on the accuracy of the model was studied. Three values of the node spacing were considered: 1, 1.25 and 1.5 mm. The mean relative errors were 4.2, 6.3 and 9.3%, respectively. The quality of the approximation of a point dipole by an array of nodes in a spherical neighbourhood did not depend significantly on the number of nodes used. The application of the method to a conduction model derived from MRI data is demonstrated. (author)

Determination of quantitative retention-activity relationships between pharmacokinetic parameters and biological effectiveness fingerprints of Salvia miltiorrhiza constituents using biopartitioning and microemulsion high-performance liquid chromatography.

Science.gov (United States)

Gao, Haoshi; Huang, Hongzhang; Zheng, Aini; Yu, Nuojun; Li, Ning

2017-11-01

In this study, we analyzed danshen (Salvia miltiorrhiza) constituents using biopartitioning and microemulsion high-performance liquid chromatography (MELC). The quantitative retention-activity relationships (QRARs) of the constituents were established to model their pharmacokinetic (PK) parameters and chromatographic retention data, and generate their biological effectiveness fingerprints. A high-performance liquid chromatography (HPLC) method was established to determine the abundance of the extracted danshen constituents, such as sodium danshensu, rosmarinic acid, salvianolic acid B, protocatechuic aldehyde, cryptotanshinone, and tanshinone IIA. And another HPLC protocol was established to determine the abundance of those constituents in rat plasma samples. An experimental model was built in Sprague Dawley (SD) rats, and calculated the corresponding PK parameterst with 3P97 software package. Thirty-five model drugs were selected to test the PK parameter prediction capacities of the various MELC systems and to optimize the chromatographic protocols. QRARs and generated PK fingerprints were established. The test included water/oil-soluble danshen constituents and the prediction capacity of the regression model was validated. The results showed that the model had good predictability. Copyright © 2017. Published by Elsevier B.V.

Oxide-cathode activation and surface temperature calculation of electron cooler

International Nuclear Information System (INIS)

Li Jie; Yang Xiaodong; Mao Lijun; Li Guohong; Yuan Youjin; Liu Zhanwen; Zhang Junhui; Yang Xiaotian; Ma Xiaoming; Yan Tailai

2011-01-01

The pollution on electron gun ceramic insulation of electron cooler restricted the operation of electron cooler at HIRFL-CSR main ring. To cool and accumulate ion beam well, the pollution was cleared and a new oxide-coated cathode was assembled. The processes of cathode replacement,vacuum chamber baking-out, and thermal decomposition of coating binders and alkaline earth metal carbonates, and cathode activation are presented. The electron gun perveance of 10.6 μA/V 1.5 was attained under the heating power of 60 W. The typical surface temperature of oxide-coated cathode that is calculated through grey-body radiation is 1 108 K which shows a comparable result to the experimental measurement 1 078 K. The perveance growth of electron gun during the electron cooler operation is also explained by partial activation of the cathode. (authors)

[Study on the chemical constituent from Buddleja purdomii].

Science.gov (United States)

Gao, Yan; Li, Chong; Zhang, Chengzhong; Xu, Yourui; Tao, Baoquan

2004-05-01

To study the chemical constituents from Buddleja purdomii W. W. Smith. The constituents were isolated and purified by various chromatographic methods and structurally identified by spectral analysis. 4 compounds were identified as vanillin (I), vanillic acid (II), acteoside (III), acteoside isomer (IV). All these compounds were obtained from this plant for the first time.

Calculations of the optical properties for FA1:Ag+ centers and CN interactions at the regular and defect sites of the LiI (0 0 1) surface: First principle calculations

International Nuclear Information System (INIS)

Abdel Aal, S.

2007-01-01

The optical properties of the F A1 :Ag + color centers and CN interactions at the flat, edge and corner surfaces of LiI (0 0 1) were investigated by using quantum mechanical configuration interaction singles (CIS) and density functional theory (DFT) ab initio methods. Clusters of variable sizes were embedded in the simulated Coulomb fields that closely approximate the Madelung fields of the host surfaces, and the nearest-neighbor ions to the defect site were allowed to relax to equilibrium in order to calculate the optical properties. The sensitivity of the calculated transition energies (Stokes shifts) of F A1 :Ag + centers as well as related optical properties such as optical-optical conversion efficiency, relaxed excited states of the defect-containing surface, orientational destruction of the point defect, recording sensitivity, and the Glasner-Tompkins empirical rule, to the coordination number of the surface ion and artificial polarization were examined. The dependance of the adsorption energies of CN at LiI (0 0 1) surface, the coadsorption of CN, and the charge transfer reactions between CN and the paramagnetic iodine vacancy on the coordination number and artificial polarization effects were also clarified

Adsorption of metal-phthalocyanine molecules onto the Si(111) surface passivated by δ doping: Ab initio calculations

Science.gov (United States)

Veiga, R. G. A.; Miwa, R. H.; McLean, A. B.

2016-03-01

We report first-principles calculations of the energetic stability and electronic properties of metal-phthalocyanine (MPc) molecules (M = Cr, Mn, Fe, Co, Ni, Cu, and Zn) adsorbed on the δ -doped Si(111)-B (√{3 }×√{3 }) reconstructed surface. (i) It can be seen that CrPc, MnPc, FePc, and CoPc are chemically anchored to the topmost Si atom. (ii) Contrastingly, the binding of the NiPc, CuPc, and ZnPc molecules to the Si (111 ) -B (√{3 }×√{3 }) surface is exclusively ruled by van der Waals interactions, the main implication being that these molecules may diffuse and rearrange to form clusters and/or self-organized structures on this surface. The electronic structure calculations reveal that in point (i), owing to the formation of the metal-Si covalent bond, the net magnetic moment of the molecule is quenched by 1 μB , remaining unchanged in point (ii). In particular, the magnetic moment of CuPc (1 μB ) is preserved after adsorption. Finally, we verify that the formation of ZnPc, CuPc, and NiPc molecular (self-assembled) arrangements on the Si(111)-B (√{3 }×√{3 } ) surface is energetically favorable, in good agreement with recent experimental findings.

Numerical Solutions of One Reduced Bethe-Salpeter Equation for the Coulombic Bound States Composed of Virtual Constituents

Science.gov (United States)

Chen, Jiao-Kai

2018-04-01

We present one reduction of the Bethe-Salpeter equation for the bound states composed of two off-mass-shell constituents. Both the relativistic effects and the virtuality effects can be considered in the obtained spinless virtuality distribution equation. The eigenvalues of the spinless virtuality distribution equation are perturbatively calculated and the bound states e+e-, μ+μ-, τ+τ-, μ+e-, and τ+e- are discussed.

Nuclei with exotic constituents

International Nuclear Information System (INIS)

Yamazaki, Toshimitsu.

1990-08-01

We discuss various interesting features in the behavior of exotic constituents of nuclei such as hyperons and mesons, in particular, with emphases on the aspect of exotic halos which are formed in general by short-range repulsion and long-range attraction. Specifically, Λ and Σ hypernuclei and pionic nuclei are discussed. (author)

Ti, Al and N adatom adsorption and diffusion on rocksalt cubic AlN (001) and (011) surfaces: Ab initio calculations

Science.gov (United States)

Mastail, C.; David, M.; Nita, F.; Michel, A.; Abadias, G.

2017-11-01

We use ab initio calculations to determine the preferred nucleation sites and migration pathways of Ti, Al and N adatoms on cubic NaCl-structure (B1) AlN surfaces, primary inputs towards a further thin film growth modelling of the TiAlN alloy system. The potential energy landscape is mapped out for both metallic species and nitrogen adatoms for two different AlN surface orientations, (001) and (110), using density functional theory. For all species, the adsorption energies on AlN(011) surface are larger than on AlN(001) surface. Ti and Al adatom adsorption energy landscapes determined at 0 K by ab initio show similar features, with stable binding sites being located in, or near, epitaxial surface positions, with Ti showing a stronger binding compared to Al. In direct contrast, N adatoms (Nad) adsorb preferentially close to N surface atoms (Nsurf), thus forming strong N2-molecule-like bonds on both AlN(001) and (011). Similar to N2 desorption mechanisms reported for other cubic transition metal nitride surfaces, in the present work we investigate Nad/Nsurf desorption on AlN(011) using a drag calculation method. We show that this process leaves a Nsurf vacancy accompanied with a spontaneous surface reconstruction, highlighting faceting formation during growth.

The calculation of the surface dose in examinations following cardiac catheterization

International Nuclear Information System (INIS)

Ewen, K.

1995-01-01

It is inevitable in examinations requiring patient exposure to high doses that the investigators and medical assistants receive high wholebody doses on account of fray radiation and, occasionally, also high partial body doses (hands) on account of the useful beam range. A number of different circumstances are adding up to create this extreme situation. In this connection, a mathematical method for the calculation of the surface dose (cutaneous dose rate) is described that is based on sets of parameters commonly used in diagnostic radiology: Set I of parameters: Tube voltage - current strength of tube - distance between focus and skin; - set II of parameters: Incidence dose rate of image intensifier - distance between focus and skin -distance between image intensifier and plane of ray incidence (skin). (orig./VHE) [de

Touching Textured Surfaces: Cells in Somatosensory Cortex Respond Both to Finger Movement and to Surface Features

Science.gov (United States)

Darian-Smith, Ian; Sugitani, Michio; Heywood, John; Karita, Keishiro; Goodwin, Antony

1982-11-01

Single neurons in Brodmann's areas 3b and 1 of the macaque postcentral gyrus discharge when the monkey rubs the contralateral finger pads across a textured surface. Both the finger movement and the spatial pattern of the surface determine this discharge in each cell. The spatial features of the surface are represented unambiguously only in the responses of populations of these neurons, and not in the responses of the constituent cells.

Towards Verification of Constituent Systems through Automated Proof

DEFF Research Database (Denmark)

Couto, Luis Diogo Monteiro Duarte; Foster, Simon; Payne, R

2014-01-01

This paper explores verification of constituent systems within the context of the Symphony tool platform for Systems of Systems (SoS). Our SoS modelling language, CML, supports various contractual specification elements, such as state invariants and operation preconditions, which can be used...... to specify contractual obligations on the constituent systems of a SoS. To support verification of these obligations we have developed a proof obligation generator and theorem prover plugin for Symphony. The latter uses the Isabelle/HOL theorem prover to automatically discharge the proof obligations arising...... from a CML model. Our hope is that the resulting proofs can then be used to formally verify the conformance of each constituent system, which is turn would result in a dependable SoS....

The determination of surface of powders by BET method using nitrogen and krypton with computer calculation of the results

International Nuclear Information System (INIS)

Dembinski, W.; Zlotowski, T.

1973-01-01

A computer program written in FORTRAN language for calculations of final results of specific surface analysis based on BET theory has been described. Two gases - nitrogen and krypton were used. A technical description of measuring apparaturs is presented as well as theoretical basis of the calculations together with statistical analysis of the results for uranium compounds powders. (author)

Screening and identification of potential bioactive constituents in a ...

African Journals Online (AJOL)

... of lung cancer, liver cancer and digestive cancer. Materials and Methods: In this study, the potential bioactive constituents of SCP were isolated and identified by chromatographic and spectroscopic methods. The immunomodulatory and DPPH radical scavenging activities of the constituents were also evaluated in vitro.

Cigarette constituent health communications for smokers: impact of chemical, imagery, and source.

Science.gov (United States)

Kowitt, Sarah; Sheeran, Paschal; Jarman, Kristen L; Ranney, Leah M; Schmidt, Allison M; Noar, Seth M; Huang, Li-Ling; Goldstein, Adam O

2017-10-03

Communication campaigns are incorporating tobacco constituent messaging to reach smokers, yet there is a dearth of research on how such messages should be constructed or will be received by smokers. In a 2x2x2 experiment, we manipulated three cigarette constituent message components: (1) the toxic constituent of tobacco (arsenic vs. lead) with a corresponding health effect, (2) the presence or absence of an evocative image, and (3) the source of the message (FDA vs. no source). We recruited smokers (N = 1,669, 55.4% women) via an online platform and randomized them to 1 of the 8 message conditions. Participants viewed the message and rated its believability and perceived effectiveness, the credibility of the message source, and action expectancies (i.e., likelihood of seeking additional information and help with quitting as a result of seeing the message). We found significant main effects of image, constituent, and source on outcomes. The use of arsenic as the constituent, the presence of an evocative image, and the FDA as the source increased the believability, source credibility, and perceived effectiveness of the tobacco constituent health message. Multiple elements of a constituent message, including type of constituent, imagery, and message source, impact their reception among smokers. Specifically, communication campaigns targeting smokers that utilize arsenic as the tobacco constituent, visual imagery, and the FDA logo may be particularly effective in changing key outcomes that are associated with subsequent attitude and behavioral changes. This paper describes how components of communication campaigns about cigarette constituents are perceived. Multiple elements of a tobacco constituent message, including type of constituent, image, and message source may influence the reception of messages among current smokers. Communication campaigns targeting smokers that utilize arsenic as the tobacco constituent, visual imagery, and the FDA logo may be particularly

Silica-forming articles having engineered surfaces to enhance resistance to creep sliding under high-temperature loading

Science.gov (United States)

Lipkin, Don Mark; Johnson, Curtis Alan; Meschter, Peter Joel; Sundaram, Sairam; Wan, Julin

2017-02-07

An article includes a silicon-containing region; at least one outer layer overlying a surface of the silicon-containing region; and a constituent layer on the surface of the silicon-containing region and between and contacting the silicon-containing region and the at least one outer layer, the constituent layer being formed by constituents of the silicon-containing region and being susceptible to creep within an operating environment of the article, wherein the silicon-containing region defines a plurality of channels and a plurality of ridges that interlock within the plurality of channels are formed in the silicon-containing region to physically interlock the at least one outer layer with the silicon-containing region through the constituent layer.

Antifungal constituents of Melicope borbonica

DEFF Research Database (Denmark)

Simonsen, Henrik Toft; Adsersen, Anne; Bremner, Paul

2004-01-01

-methoxycoumarin, cedrelopsin and psoralen], two sesquiterpenes (alpha-curcumene and 3,6-epidioxy-1,10-bisaboladiene), eugenol, methyleugenol and a lignan (sesamin) were isolated. None of the isolated constituents exhibited antiin fl ammatory activity in vitro. No alkaloids were detected....

Test calculations of photoneutrons emission from surface of uranium sphere irradiated by 28 MeV electrons

International Nuclear Information System (INIS)

Blokhin, A.I.; Degtyarev, I.I.

2002-01-01

In this paper the results of physical verification for the BOFOD photonuclear data files are reported, available for the uranium isotopes U 235 , U 238 . These results were compared with calculated data by the parameterization driven model of photonuclear reaction and experimental data. Experimental data of photoneutron yields from surface of uranium sphere irradiated by 28 MeV electrons are used for a verification. Both calculations have been carried out with the RTS and T general purpose Monte Carlo code with detailed electron-photon-nucleon transport simulation using the ENDF/B-VI and EPDL evaluated data libraries

Effect of Cu Alloying on S Poisoning of Ni Surfaces and Nanoparticle Morphologies Using Ab-Initio Thermodynamics Calculations.

Science.gov (United States)

Kim, Ji-Su; Kim, Byung-Kook; Kim, Yeong-Cheol

2015-10-01

We investigated the effect of Cu alloying on S poisoning of Ni surfaces and nanoparticle morphologies using ab-initio thermodynamics calculations. Based on the Cu segregation energy and the S adsorption energy, the surface energy and nanoparticle morphology of pure Ni, pure Cu, and NiCu alloys were evaluated as functions of the chemical potential of S and the surface orientations of (100), (110), and (111). The constructed nanoparticle morphology was varied as a function of chemical potential of S. We find that the Cu added to Ni for NiCu alloys is strongly segregated into the top surface, and increases the S tolerance of the NiCu nanoparticles.

Auger electron spectroscopy of alloy surfaces

International Nuclear Information System (INIS)

Overbury, S.H.; Somorjai, G.A.

1975-03-01

Regular solution models are used to predict surface segregation of the constituent of lowest surface free energy in homogeneous multicomponent systems. Analysis of the Auger electron emission intensities from alloys yield the surface composition and the depth distribution of the composition near the surface. Auger Electron Spectroscopy (AES) studies of the surface composition of the Ag--Au and Pb--In systems have been carried out as a function of bulk composition and temperature. Although these alloys have very different regular solution parameters their surface compositions are predictable by the regular solution models. (U.S.)

40 CFR 264.342 - Principal organic hazardous constituents (POHCs).

Science.gov (United States)

2010-07-01

...) Principal Organic Hazardous Constituents (POHCs) in the waste feed must be treated to the extent required by... organic constituents in the waste and on their concentration or mass in the waste feed, considering the... (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE...

Efficacy of surface error corrections to density functional theory calculations of vacancy formation energy in transition metals.

Science.gov (United States)

Nandi, Prithwish Kumar; Valsakumar, M C; Chandra, Sharat; Sahu, H K; Sundar, C S

2010-09-01

We calculate properties like equilibrium lattice parameter, bulk modulus and monovacancy formation energy for nickel (Ni), iron (Fe) and chromium (Cr) using Kohn-Sham density functional theory (DFT). We compare the relative performance of local density approximation (LDA) and generalized gradient approximation (GGA) for predicting such physical properties for these metals. We also make a relative study between two different flavors of GGA exchange correlation functional, namely PW91 and PBE. These calculations show that there is a discrepancy between DFT calculations and experimental data. In order to understand this discrepancy in the calculation of vacancy formation energy, we introduce a correction for the surface intrinsic error corresponding to an exchange correlation functional using the scheme implemented by Mattsson et al (2006 Phys. Rev. B 73 195123) and compare the effectiveness of the correction scheme for Al and the 3d transition metals.

[Studies on the chemical constituents of Portulaca oleracea].

Science.gov (United States)

Liu, Ce-jia; Liu, Dian-yu; Xiang, Lan; Zhou, Wen; Shao, Ning-ning

2009-11-01

To study the chemical constituents of Portulaca oleracea. The constituents were isolated by column chromatography and identified on the basis of physicochemical and spectral data. Five compounds were isolated from 70% ethanol extract of this plant and their structures were elucidated as cyclo (Phe-Ile) (1), cycle (Tyr-Ala) (2), adenine (3), friedelin (4) and isoselachoceric acid (5). Compounds 1-5 are isolated from Portulaca oleracea for the first time.

Products of Irreducible Characters Having Complex-Valued Constituents

Directory of Open Access Journals (Sweden)

Lisa R. Hendrixson

2017-06-01

Full Text Available First, we prove that when a finite solvable group $G$ has a faithful irreducible character $\\chi$ such that $\\chi\\overline{\\chi}$ has two irreducible constituents, both must be real-valued. Then, we study the situation where $\\chi\\overline{\\chi}$ has exactly three distinct nonprincipal irreducible constituents, two of which are complex conjugates. In this case, we prove that $G$ has derived length bounded above by $6$.

An algorithm for calculating unsteady flow with free surface; Ein Verfahren zur Berechnung instationaerer Stroemungen mit freier Oberflaeche

Energy Technology Data Exchange (ETDEWEB)

Janetzky, B.

2001-07-01

A numerical model for the transient, free surface flow is implemented in a Finite-Element program for the unsteady calculation of incompressible flow with free surface. The program is used to calculate the flow in different components of a hydraulic turbine, the Pelton turbine. The movement of the fluid with free surface is described mathematically by introducing a partial differential equation for the volume fraction. This equation is simply a transport equation for f, i.e. the volume fraction is advected with the flow in time. The equations is solved numerically. (orig.) [German] Es wird ein Verfahren zur Modellierung von veraenderlichen, freien Oberflaechen vorgestellt und in einem Finite-Elemente-Programm zur numerischen Berechnung von instationaeren, inkompressiblen Stroemungen implementiert. Die veraenderliche, freie Oberflaeche wird mit einem Volume-Of-Fluid Ansatz erfasst. Zur Approximierung der freien Oberflaeche werden stueckweise konstante oder gestufte Verlaeufe im Element angesetzt. Es werden die Eigenschaften des Verfahrens an ausgewaehlten Beispielen mit freier Oberflaeche untersucht. Das erweiterte Programm wird auf instationaere Stroemungen mit freier Oberflaeche in einer hydraulischen Maschine, der Peltonturbine, angewandt. (orig.)

Quantum calculations of the IR spectrum of liquid water using ab initio and model potential and dipole moment surfaces and comparison with experiment

Energy Technology Data Exchange (ETDEWEB)

Liu, Hanchao; Wang, Yimin; Bowman, Joel M. [Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322 (United States)

2015-05-21

The calculation and characterization of the IR spectrum of liquid water have remained a challenge for theory. In this paper, we address this challenge using a combination of ab initio approaches, namely, a quantum treatment of IR spectrum using the ab initio WHBB water potential energy surface and a refined ab initio dipole moment surface. The quantum treatment is based on the embedded local monomer method, in which the three intramolecular modes of each embedded H{sub 2}O monomer are fully coupled and also coupled singly to each of six intermolecular modes. The new dipole moment surface consists of a previous spectroscopically accurate 1-body dipole moment surface and a newly fitted ab initio intrinsic 2-body dipole moment. A detailed analysis of the new dipole moment surface in terms of the coordinate dependence of the effective atomic charges is done along with tests of it for the water dimer and prism hexamer double-harmonic spectra against direct ab initio calculations. The liquid configurations are taken from previous molecular dynamics calculations of Skinner and co-workers, using the TIP4P plus E3B rigid monomer water potential. The IR spectrum of water at 300 K in the range of 0–4000 cm{sup −1} is calculated and compared with experiment, using the ab initio WHBB potential and new ab initio dipole moment, the q-TIP4P/F potential, which has a fixed-charged description of the dipole moment, and the TTM3-F potential and dipole moment surfaces. The newly calculated ab initio spectrum is in very good agreement with experiment throughout the above spectral range, both in band positions and intensities. This contrasts to results with the other potentials and dipole moments, especially the fixed-charge q-TIP4P/F model, which gives unrealistic intensities. The calculated ab initio spectrum is analyzed by examining the contribution of various transitions to each band.

Quantum calculations of the IR spectrum of liquid water using ab initio and model potential and dipole moment surfaces and comparison with experiment

International Nuclear Information System (INIS)

Liu, Hanchao; Wang, Yimin; Bowman, Joel M.

2015-01-01

The calculation and characterization of the IR spectrum of liquid water have remained a challenge for theory. In this paper, we address this challenge using a combination of ab initio approaches, namely, a quantum treatment of IR spectrum using the ab initio WHBB water potential energy surface and a refined ab initio dipole moment surface. The quantum treatment is based on the embedded local monomer method, in which the three intramolecular modes of each embedded H 2 O monomer are fully coupled and also coupled singly to each of six intermolecular modes. The new dipole moment surface consists of a previous spectroscopically accurate 1-body dipole moment surface and a newly fitted ab initio intrinsic 2-body dipole moment. A detailed analysis of the new dipole moment surface in terms of the coordinate dependence of the effective atomic charges is done along with tests of it for the water dimer and prism hexamer double-harmonic spectra against direct ab initio calculations. The liquid configurations are taken from previous molecular dynamics calculations of Skinner and co-workers, using the TIP4P plus E3B rigid monomer water potential. The IR spectrum of water at 300 K in the range of 0–4000 cm −1 is calculated and compared with experiment, using the ab initio WHBB potential and new ab initio dipole moment, the q-TIP4P/F potential, which has a fixed-charged description of the dipole moment, and the TTM3-F potential and dipole moment surfaces. The newly calculated ab initio spectrum is in very good agreement with experiment throughout the above spectral range, both in band positions and intensities. This contrasts to results with the other potentials and dipole moments, especially the fixed-charge q-TIP4P/F model, which gives unrealistic intensities. The calculated ab initio spectrum is analyzed by examining the contribution of various transitions to each band

A Mathematical Method to Calculate Tumor Contact Surface Area: An Effective Parameter to Predict Renal Function after Partial Nephrectomy.

Science.gov (United States)

Hsieh, Po-Fan; Wang, Yu-De; Huang, Chi-Ping; Wu, Hsi-Chin; Yang, Che-Rei; Chen, Guang-Heng; Chang, Chao-Hsiang

2016-07-01

We proposed a mathematical formula to calculate contact surface area between a tumor and renal parenchyma. We examined the applicability of using contact surface area to predict renal function after partial nephrectomy. We performed this retrospective study in patients who underwent partial nephrectomy between January 2012 and December 2014. Based on abdominopelvic computerized tomography or magnetic resonance imaging, we calculated the contact surface area using the formula (2*π*radius*depth) developed by integral calculus. We then evaluated the correlation between contact surface area and perioperative parameters, and compared contact surface area and R.E.N.A.L. (Radius/Exophytic/endophytic/Nearness to collecting system/Anterior/Location) score in predicting a reduction in renal function. Overall 35, 26 and 45 patients underwent partial nephrectomy with open, laparoscopic and robotic approaches, respectively. Mean ± SD contact surface area was 30.7±26.1 cm(2) and median (IQR) R.E.N.A.L. score was 7 (2.25). Spearman correlation analysis showed that contact surface area was significantly associated with estimated blood loss (p=0.04), operative time (p=0.04) and percent change in estimated glomerular filtration rate (p contact surface area and R.E.N.A.L. score independently affected percent change in estimated glomerular filtration rate (p contact surface area was a better independent predictor of a greater than 10% change in estimated glomerular filtration rate compared to R.E.N.A.L. score (AUC 0.86 vs 0.69). Using this simple mathematical method, contact surface area was associated with surgical outcomes. Compared to R.E.N.A.L. score, contact surface area was a better predictor of functional change after partial nephrectomy. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

New upper limits for atmospheric constituents on Io

Science.gov (United States)

Fink, U.; Larson, H. P.; Gautier, T. N., III

1976-01-01

A spectrum of Io from 0.86 to 2.7 microns with a resolution of 3.36 per cm and a signal to rms noise ratio of 120 is presented. No absorptions due to any atmospheric constituents on Io could be found in the spectrum. Upper limits of 0.12 cm-atm for NH3, 0.12 cm-atm for CH4, 0.4 cm-atm for N2O, and 24 cm-atm for H2S were determined. Laboratory spectra of ammonia frosts as a function of temperature were compared with the spectrum of Io and showed this frost not to be present at the surface of Io. A search for possible resonance lines of carbon, silicon, and sulfur, as well as the 1.08-micron line of helium, proved negative. Upper emission limits of 60, 18, 27, and 60 kilorayleighs, respectively, were established for these lines.

Monte Carlo calculation of secondary electron emission from carbon-surface by obliquely incident particles

International Nuclear Information System (INIS)

Ohya, Kaoru; Kawata, Jun; Mori, Ichiro

1990-01-01

Incidence angle dependences of secondary electron emission from a carbon surface by low energy electron and hydrogen atom are calculated using Monte Carlo simulations on the kinetic emission model. The calculation shows very small increase or rather decrease of the secondary electron yield with oblique incidence. It is explained in terms of not only multiple elastic collisions of incident particles with the carbon atoms but also small penetration depth of the particles comparable with the escape depth of secondary electrons. In addition, the two types of secondary electron emission are distinguished by using the secondary electron yield statistics; one is the emission due to trapped particles in the carbon, and the other is that due to backscattered particles. The high-yield component of the statistics on oblique incidence is more suppressed than those on normal incidence. (author)

Density functional calculation of electronic surface structure and Fe adsorption on ZnO (0001) and (000 anti 1)

Energy Technology Data Exchange (ETDEWEB)

Pal, Sougata; Jasper-Toennies, Torben; Hack, Michael; Pehlke, Eckhard [Institut fuer Theoretische Physik und Astrophysik, Universitaet Kiel (Germany)

2011-07-01

The structure and electronic properties of the ZnO(0001) and ZnO(000 anti 1) surfaces as studied by density functional calculations are presented. The stability of the surface has already been investigated by various groups. The electronic surface band structure, however, in particular the existence of surface states and the differences between experimental band dispersion for both terminations, still appears to pose open problems. To address these issues, we compare Kohn Sham band structures and electrostatic potentials close to the surface for the relaxed (1 x 1)-surface, (2 x 2) vacancy reconstructions, and surfaces with pits. In particular the effect of the bending of the electrostatic potential at the surface on the eigenstates is quantified. Comparing the adsorption energies of Fe atoms for various adsorption sites on ZnO(000 anti 1), the fcc hollow position turned out to be energetically favorable. The oxidation state of the Fe atom is derived from the projected density of states.

Theory of quasiparticle surface states in semiconductor surfaces

International Nuclear Information System (INIS)

Hybertsen, M.S.; Louie, S.G.

1988-01-01

A first-principles theory of the quasiparticle surface-state energies on semiconductor surfaces is developed. The surface properties are calculated using a repeated-slab geometry. Many-body effects due to the electron-electron interaction are represented by the electron self-energy operator including the full surface Green's function and local fields and dynamical screening effects in the Coulomb interaction. Calculated surface-state energies for the prototypical Si(111):As and Ge(111):As surfaces are presented. The calculated energies and dispersions for the occupied surface states (resonances) are in excellent agreement with recent angle-resolved photoemission data. Predictions are made for the position of empty surface states on both surfaces which may be experimentally accessible. The resulting surface state gap at Gamma-bar for Si(111):As agrees with recent scanning-tunneling-spectroscopy measurements. Comparison of the present results to eigenvalues from the local-density-functional calculation reveals substantial corrections for the gaps between empty and occupied surface states. This correction is found to depend on the character of the surface states involved

Method for verification of constituents of a process stream

Energy Technology Data Exchange (ETDEWEB)

Baylor, L.C.; Buchanan, B.R.; O`Rourke, P.E.

1993-01-01

This invention is comprised of a method for validating a process stream for the presence or absence of a substance of interest such as a chemical warfare agent; that is, for verifying that a chemical warfare agent is present in an input line for feeding the agent into a reaction vessel for destruction, or, in a facility for producing commercial chemical products, that a constituent of the chemical warfare agent has not been substituted for the proper chemical compound. The method includes the steps of transmitting light through a sensor positioned in the feed line just before the chemical constituent in the input line enters the reaction vessel, measuring an optical spectrum of the chemical constituent from the light beam transmitted through it, and comparing the measured spectrum to a reference spectrum of the chemical agent and preferable also reference spectra of surrogates. A signal is given if the chemical agent is not entering a reaction vessel for destruction, or if a constituent of a chemical agent is added to a feed line in substitution of the proper chemical compound.

Calculated energy distributions for light 0.25--18-keV ions scattered from solid surfaces

International Nuclear Information System (INIS)

Robinson, J.E.; Harms, A.A.; Karapetsas, S.K.

1975-01-01

Scattered energy distributions are calculated for light ions incident on Nb and Mo surfaces of interest for controlled nulcear fusion reactors. The scattered energy is found to vary as a function of the reflection coefficient between a multiple-collision limit at low energies and a single-collision Rutherford scattering limit at high energies. High-energy peaking of the scattered particle distributions is also found for low incident energies

Strange mesonic transition form factor in the chiral constituent quark model

International Nuclear Information System (INIS)

Ito, H.; Ramsey-Musolf, M.J.

1998-01-01

The form factor g ρπ (S) (Q 2 ) of the strange vector current transition matrix element left-angle ρ|bar sγ μ s|π right-angle is calculated within the chiral quark model. A strange vector current of the constituent U and D quarks is induced by kaon radiative corrections and this mechanism yields the nonvanishing values of g ρπ (S) (0). The numerical result at the photon point is consistent with the one given by the φ-meson dominance model, but the falloff in the Q 2 dependence is faster than the monopole form factor. Mesonic radiative corrections are also examined for the electromagnetic ρ-to-π and K * -to-K transition amplitudes. copyright 1998 The American Physical Society

Chemical constituents of Asparagus

Science.gov (United States)

Negi, J. S.; Singh, P.; Joshi, G. P.; Rawat, M. S.; Bisht, V. K.

2010-01-01

Asparagus species (family Liliaceae) are medicinal plants of temperate Himalayas. They possess a variety of biological properties, such as being antioxidants, immunostimulants, anti-inflammatory, antihepatotoxic, antibacterial, antioxytocic, and reproductive agents. The article briefly reviews the isolated chemical constituents and the biological activities of the plant species. The structural formula of isolated compounds and their distribution in the species studied are also given. PMID:22228964

Space-time patterns of trends in stratospheric constituents derived from UARS measurements

Science.gov (United States)

Randel, William J.; Wu, Fei; Russell, James M.; Waters, Joe

1999-02-01

The spatial and temporal behavior of low-frequency changes (trends) in stratospheric constituents measured by instruments on the Upper Atmosphere Research Satellite (UARS) during 1991-98 is investigated. The data include CH4, H2O, HF, HCl, O3, and NO2 from the Halogen Occultation Experiment (HALOE), and O3, ClO, and HNO3 from the Microwave Limb Sounder (MLS). Time series of global anomalies are analyzed by linear regression and empirical orthogonal function analysis. Each of the constituents show significant linear trends over at least some region of the stratosphere, and the spatial patterns exhibit coupling between the different species. Several of the constituents (namely CH4, H2O, HF, HCl, O3, and NO2) exhibit a temporal change in trend rates, with strong changes prior to 1996 and weaker (or reversed) trends thereafter. Positive trends are observed in upper stratospheric ClO, with a percentage rate during 1993-97 consistent with stratospheric HCl increases and with tropospheric chlorine emission rates. Significant negative trends in ozone in the tropical middle stratosphere are found in both HALOE and MLS data during 1993-97, together with positive trends in the tropics near 25 km. These trends are very different from the decadal-scale ozone trends observed since 1979, and this demonstrates the variability of trends calculated over short time periods. Positive trends in NO2 are found in the tropical middle stratosphere, and spatial coincidence to the observed ozone decreases suggests the ozone is responding to the NO2 increase. Significant negative trends in HNO3 are found in the lower stratosphere of both hemispheres. These coupled signatures offer a fingerprint of chemical evolution in the stratosphere for the UARS time frame.

Constituent gluon interpretation of glueballs and gluelumps

International Nuclear Information System (INIS)

Boulanger, N.; Buisseret, F.; Mathieu, V.; Semay, C.

2008-01-01

Arguments are given that support the interpretation of the lattice QCD glueball and gluelump spectra in terms of bound states of massless constituent gluons with helicity 1. In this scheme, we show that the mass hierarchy of the currently known gluelumps and glueballs is mainly due to the number of constituent gluons and can be understood within a simple flux tube model. It is also argued that the lattice QCD 0 +- glueball should be seen as a four-gluon bound state. We finally predict the mass of the 0 - state, not yet computed in lattice QCD. (orig.)

Research on calculation of the IOL tilt and decentration based on surface fitting.

Science.gov (United States)

Li, Lin; Wang, Ke; Yan, Yan; Song, Xudong; Liu, Zhicheng

2013-01-01

The tilt and decentration of intraocular lens (IOL) result in defocussing, astigmatism, and wavefront aberration after operation. The objective is to give a method to estimate the tilt and decentration of IOL more accurately. Based on AS-OCT images of twelve eyes from eight cases with subluxation lens after operation, we fitted spherical equation to the data obtained from the images of the anterior and posterior surfaces of the IOL. By the established relationship between IOL tilt (decentration) and the scanned angle, at which a piece of AS-OCT image was taken by the instrument, the IOL tilt and decentration were calculated. IOL tilt angle and decentration of each subject were given. Moreover, the horizontal and vertical tilt was also obtained. Accordingly, the possible errors of IOL tilt and decentration existed in the method employed by AS-OCT instrument. Based on 6-12 pieces of AS-OCT images at different directions, the tilt angle and decentration values were shown, respectively. The method of the surface fitting to the IOL surface can accurately analyze the IOL's location, and six pieces of AS-OCT images at three pairs symmetrical directions are enough to get tilt angle and decentration value of IOL more precisely.

Research on Calculation of the IOL Tilt and Decentration Based on Surface Fitting

Directory of Open Access Journals (Sweden)

Lin Li

2013-01-01

Full Text Available The tilt and decentration of intraocular lens (IOL result in defocussing, astigmatism, and wavefront aberration after operation. The objective is to give a method to estimate the tilt and decentration of IOL more accurately. Based on AS-OCT images of twelve eyes from eight cases with subluxation lens after operation, we fitted spherical equation to the data obtained from the images of the anterior and posterior surfaces of the IOL. By the established relationship between IOL tilt (decentration and the scanned angle, at which a piece of AS-OCT image was taken by the instrument, the IOL tilt and decentration were calculated. IOL tilt angle and decentration of each subject were given. Moreover, the horizontal and vertical tilt was also obtained. Accordingly, the possible errors of IOL tilt and decentration existed in the method employed by AS-OCT instrument. Based on 6–12 pieces of AS-OCT images at different directions, the tilt angle and decentration values were shown, respectively. The method of the surface fitting to the IOL surface can accurately analyze the IOL’s location, and six pieces of AS-OCT images at three pairs symmetrical directions are enough to get tilt angle and decentration value of IOL more precisely.

Volatile constituents of Glechoma hirsute Waldst. & Kit. and G ...

African Journals Online (AJOL)

The essential oils of two Glechoma species from Serbia have been analyzed by GC and GC/MS. Eighty eight and two hundred thirty eight constituents identified accounted for 90.6 and 86.6% of the total oils of G. hirsuta Waldst. & Kit. and G. hederacea L., respectively. In both oils the dominant constituent class was the ...

[Chemical constituents of Aconitum tanguticum].

Science.gov (United States)

Luo, Ming; Lin, Limei; Li, Chun; Wang, Zhimin; Guo, Wubao

2012-05-01

To study the chemical constituents isolated from the whole plant of Aconitum tanguticum. Chemical constituents were isolated and purified from the title plant by using a combination of various chromatographic techniques including column chromatography over silica gel, Sephadex LH-20, ODS and preparative HPLC. Their structures were elucidated by spectroscopic techniques including 1H-NMR, 13C-NMR, 2D-NMR, and ESI-MS. Seven compounds were isolated from this plant and their structures were identified as kaempferol-3-O-[alpha-L-rhamnopyranosyl-(1-->6)-beta-D-galactopyranoside]-7-O-alpha-L-rhamnopyrano-side (1), kaempferol-3-O-[alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside]-7-O-alpha-L-rhamnopyranoside (2), kaempferol 7-O-alpha-L-rhamnopyranoside (3), gentiopieroside (4), vomifoliol-9-O-beta-D-glucopyranoside (5), dihydrovomifoliol-9-O-beta-D-glucopyranoside (6) and 3,4-dihydroxyphenyl alcohol-beta-D-glucopyranoside (7). All the compounds were isolated from this plant for the first time.

An extract of a formula used in the traditional chinese medicine (Buzhong Yi Qi Wan) alters the labeling of blood constituents with technetium-99m

Energy Technology Data Exchange (ETDEWEB)

Giani, Tania Santos; Paoli, Severo de; Brandao-Neto, Jose; Medeiros, Aldo da Cunha [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Centro de Ciencias da Saude. Programa de Pos-graduacao em Ciencias da Saude]. E-mail: tgiani@gmail.com; Presta, Giuseppe Antonio; Maiworm, Adalgisa Ieda; Santos Filho, Sebastiao David; Fonseca, Adenilson de Souza da [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. de Biologia Roberto Alcantara Gomes. Lab. de Radiofarmacia Experimental; Bernardo-Filho, Mario [Instituto Nacional de Cancer (INCa), Rio de Janeiro, RJ (Brazil). Centro de Pesquisa Basica

2007-09-15

Buzhong Yi Qi Wan (Buzhong) is a medicinal herb widely used in Traditional Chinese Medicine to treat the digestive and circulatory systems. Red blood cell and plasma proteins labeled with technetium-99m ({sup 99m}Tc) are used in nuclear medicine. The aim of this work was to investigate the effects of an aqueous Buzhong extract on the labeling of blood constituents with {sup 99m}Tc. Heparinized blood (Wistar rats) was incubated in vitro with different Buzhong extract concentrations and {sup 99m}Tc-labeling was performed. Plasma (P) and blood cells (BC) were separated and soluble (SF-P, SF-BC) and insoluble (IF-P, IF-BC) fractions were isolated. The radioactivity on blood constituents was determined and the percentage of incorporated radioactivity (%ATI) was calculated. Buzhong extract at the highest concentrations used altered significantly (p<0.05) the %ATI in blood constituents. Substances present in the Buzhong extract could alter the cellular membrane and/or generation of free radicals that have oxidant properties modifying the labeling of blood constituents with {sup 99}mTc. (author)

Impact of thermoplastic mask on X-ray surface dose calculated with Monte Carlo code

International Nuclear Information System (INIS)

Zhao Yanqun; Li Jie; Wu Liping; Wang Pei; Lang Jinyi; Wu Dake; Xiao Mingyong

2010-01-01

Objective: To calculate the effects of thermoplastic mask on X-ray surface dose. Methods: The BEAMnrc Monte Carlo Code system, designed especially for computer simulation of radioactive sources, was performed to evaluate the effects of thermoplastic mask on X-ray surface dose.Thermoplastic mask came from our center with a material density of 1.12 g/cm 2 . The masks without holes, with holes size of 0.1 cm x 0.1 cm, and with holes size of 0. 1 cm x 0.2 cm, and masks with different depth (0.12 cm and 0.24 cm) were evaluated separately. For those with holes, the material width between adjacent holes was 0.1 cm. Virtual masks with a material density of 1.38 g/cm 3 without holes with two different depths were also evaluated. Results: Thermoplastic mask affected X-rays surface dose. When using a thermoplastic mask with the depth of 0.24 cm without holes, the surface dose was 74. 9% and 57.0% for those with the density of 1.38 g/cm 3 and 1.12 g/cm 3 respectively. When focusing on the masks with the density of 1.12 g/cm 3 , the surface dose was 41.2% for those with 0.12 cm depth without holes; 57.0% for those with 0. 24 cm depth without holes; 44.5% for those with 0.24 cm depth with holes size of 0.1 cm x 0.2 cm;and 54.1% for those with 0.24 cm depths with holes size of 0.1 cm x 0.1 cm.Conclusions: Using thermoplastic mask during the radiation increases patient surface dose. The severity is relative to the hole size and the depth of thermoplastic mask. The surface dose change should be considered in radiation planning to avoid severe skin reaction. (authors)

Error rate of automated calculation for wound surface area using a digital photography.

Science.gov (United States)

Yang, S; Park, J; Lee, H; Lee, J B; Lee, B U; Oh, B H

2018-02-01

Although measuring would size using digital photography is a quick and simple method to evaluate the skin wound, the possible compatibility of it has not been fully validated. To investigate the error rate of our newly developed wound surface area calculation using digital photography. Using a smartphone and a digital single lens reflex (DSLR) camera, four photographs of various sized wounds (diameter: 0.5-3.5 cm) were taken from the facial skin model in company with color patches. The quantitative values of wound areas were automatically calculated. The relative error (RE) of this method with regard to wound sizes and types of camera was analyzed. RE of individual calculated area was from 0.0329% (DSLR, diameter 1.0 cm) to 23.7166% (smartphone, diameter 2.0 cm). In spite of the correction of lens curvature, smartphone has significantly higher error rate than DSLR camera (3.9431±2.9772 vs 8.1303±4.8236). However, in cases of wound diameter below than 3 cm, REs of average values of four photographs were below than 5%. In addition, there was no difference in the average value of wound area taken by smartphone and DSLR camera in those cases. For the follow-up of small skin defect (diameter: <3 cm), our newly developed automated wound area calculation method is able to be applied to the plenty of photographs, and the average values of them are a relatively useful index of wound healing with acceptable error rate. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The transfer of the native constituent power to an international authority

OpenAIRE

Konan , Line

2007-01-01

The transfer of the original constituent power comes when the adoption of a constitution falls under a procedure which moves the constitutional decision-making centre towards an external authority in the State. However in constitutional law, the constituent procedure concerns by nature the expression of the State?s sovereignty. In the same way, in international law, the right of peoples to self determination implies for the constituent people, the freedom in the determination of its political...

Estimating Concentrations of Road-Salt Constituents in Highway-Runoff from Measurements of Specific Conductance

Science.gov (United States)

Granato, Gregory E.; Smith, Kirk P.

1999-01-01

Discrete or composite samples of highway runoff may not adequately represent in-storm water-quality fluctuations because continuous records of water stage, specific conductance, pH, and temperature of the runoff indicate that these properties fluctuate substantially during a storm. Continuous records of water-quality properties can be used to maximize the information obtained about the stormwater runoff system being studied and can provide the context needed to interpret analyses of water samples. Concentrations of the road-salt constituents calcium, sodium, and chloride in highway runoff were estimated from theoretical and empirical relations between specific conductance and the concentrations of these ions. These relations were examined using the analysis of 233 highwayrunoff samples collected from August 1988 through March 1995 at four highway-drainage monitoring stations along State Route 25 in southeastern Massachusetts. Theoretically, the specific conductance of a water sample is the sum of the individual conductances attributed to each ionic species in solution-the product of the concentrations of each ion in milliequivalents per liter (meq/L) multiplied by the equivalent ionic conductance at infinite dilution-thereby establishing the principle of superposition. Superposition provides an estimate of actual specific conductance that is within measurement error throughout the conductance range of many natural waters, with errors of less than ?5 percent below 1,000 microsiemens per centimeter (?S/cm) and ?10 percent between 1,000 and 4,000 ?S/cm if all major ionic constituents are accounted for. A semi-empirical method (adjusted superposition) was used to adjust for concentration effects-superposition-method prediction errors at high and low concentrations-and to relate measured specific conductance to that calculated using superposition. The adjusted superposition method, which was developed to interpret the State Route 25 highway-runoff records, accounts for

Growth of binary solid solution single crystals and calculation of melt surface displacement velocity

International Nuclear Information System (INIS)

Agamaliyev, Z.A.; Tahirov, V.I.; Hasanov, Z.Y.; Quliyev, A.F.

2007-01-01

A binary solid solution single crystal growth method has been worked out. Cylinder feeding alloy with complex content distribution and truncated cone crucible are used. Second component distribution coefficient is more than unit. Content distribution along grown crystal is found by solving continuity equation. After reaching dynamic equilibrium state second component concentration in grown crystal is saturated the value of which is less than the average ona in the feeding alloy. Using the method Ge-Si perfect single crystals has been grown. Calculation method of melt surface displacement velocity has been offered as well

Brain correlates of constituent structure in sign language comprehension.

Science.gov (United States)

Moreno, Antonio; Limousin, Fanny; Dehaene, Stanislas; Pallier, Christophe

2018-02-15

During sentence processing, areas of the left superior temporal sulcus, inferior frontal gyrus and left basal ganglia exhibit a systematic increase in brain activity as a function of constituent size, suggesting their involvement in the computation of syntactic and semantic structures. Here, we asked whether these areas play a universal role in language and therefore contribute to the processing of non-spoken sign language. Congenitally deaf adults who acquired French sign language as a first language and written French as a second language were scanned while watching sequences of signs in which the size of syntactic constituents was manipulated. An effect of constituent size was found in the basal ganglia, including the head of the caudate and the putamen. A smaller effect was also detected in temporal and frontal regions previously shown to be sensitive to constituent size in written language in hearing French subjects (Pallier et al., 2011). When the deaf participants read sentences versus word lists, the same network of language areas was observed. While reading and sign language processing yielded identical effects of linguistic structure in the basal ganglia, the effect of structure was stronger in all cortical language areas for written language relative to sign language. Furthermore, cortical activity was partially modulated by age of acquisition and reading proficiency. Our results stress the important role of the basal ganglia, within the language network, in the representation of the constituent structure of language, regardless of the input modality. Copyright © 2017 Elsevier Inc. All rights reserved.

[Studies on the chemical constituents of Buddleja albiflora (II)].

Science.gov (United States)

Zhang, Hai-Ping; Tao, Liang

2010-06-01

To study the chemical constituents of Buddleja albiflora. The constituents were isolated by column chromatography and their structures were elucidated by spectroscopic analyses. seven compounds were isolated and identified as aucubin (1), catalpol (2), acteoside (3), martynoside (4), ursolicacid (5), daucosterol (6), beta-sitosterol-3-0-beta-D-(6'-0-palmitate) glucopyranosisde (7). All these compounds are obtained from Buddleja albiflora for the first time.

MULTIMODE quantum calculations of vibrational energies and IR spectrum of the NO⁺(H₂O) cluster using accurate potential energy and dipole moment surfaces.

Science.gov (United States)

Homayoon, Zahra

2014-09-28

A new, full (nine)-dimensional potential energy surface and dipole moment surface to describe the NO(+)(H2O) cluster is reported. The PES is based on fitting of roughly 32,000 CCSD(T)-F12/aug-cc-pVTZ electronic energies. The surface is a linear least-squares fit using a permutationally invariant basis with Morse-type variables. The PES is used in a Diffusion Monte Carlo study of the zero-point energy and wavefunction of the NO(+)(H2O) and NO(+)(D2O) complexes. Using the calculated ZPE the dissociation energies of the clusters are reported. Vibrational configuration interaction calculations of NO(+)(H2O) and NO(+)(D2O) using the MULTIMODE program are performed. The fundamental, a number of overtone, and combination states of the clusters are reported. The IR spectrum of the NO(+)(H2O) cluster is calculated using 4, 5, 7, and 8 modes VSCF/CI calculations. The anharmonic, coupled vibrational calculations, and IR spectrum show very good agreement with experiment. Mode coupling of the water "antisymmetric" stretching mode with the low-frequency intermolecular modes results in intensity borrowing.

MULTIMODE quantum calculations of vibrational energies and IR spectrum of the NO+(H2O) cluster using accurate potential energy and dipole moment surfaces

Science.gov (United States)

Homayoon, Zahra

2014-09-01

A new, full (nine)-dimensional potential energy surface and dipole moment surface to describe the NO+(H2O) cluster is reported. The PES is based on fitting of roughly 32 000 CCSD(T)-F12/aug-cc-pVTZ electronic energies. The surface is a linear least-squares fit using a permutationally invariant basis with Morse-type variables. The PES is used in a Diffusion Monte Carlo study of the zero-point energy and wavefunction of the NO+(H2O) and NO+(D2O) complexes. Using the calculated ZPE the dissociation energies of the clusters are reported. Vibrational configuration interaction calculations of NO+(H2O) and NO+(D2O) using the MULTIMODE program are performed. The fundamental, a number of overtone, and combination states of the clusters are reported. The IR spectrum of the NO+(H2O) cluster is calculated using 4, 5, 7, and 8 modes VSCF/CI calculations. The anharmonic, coupled vibrational calculations, and IR spectrum show very good agreement with experiment. Mode coupling of the water "antisymmetric" stretching mode with the low-frequency intermolecular modes results in intensity borrowing.

MULTIMODE quantum calculations of vibrational energies and IR spectrum of the NO+(H2O) cluster using accurate potential energy and dipole moment surfaces

International Nuclear Information System (INIS)

Homayoon, Zahra

2014-01-01

A new, full (nine)-dimensional potential energy surface and dipole moment surface to describe the NO + (H 2 O) cluster is reported. The PES is based on fitting of roughly 32 000 CCSD(T)-F12/aug-cc-pVTZ electronic energies. The surface is a linear least-squares fit using a permutationally invariant basis with Morse-type variables. The PES is used in a Diffusion Monte Carlo study of the zero-point energy and wavefunction of the NO + (H 2 O) and NO + (D 2 O) complexes. Using the calculated ZPE the dissociation energies of the clusters are reported. Vibrational configuration interaction calculations of NO + (H 2 O) and NO + (D 2 O) using the MULTIMODE program are performed. The fundamental, a number of overtone, and combination states of the clusters are reported. The IR spectrum of the NO + (H 2 O) cluster is calculated using 4, 5, 7, and 8 modes VSCF/CI calculations. The anharmonic, coupled vibrational calculations, and IR spectrum show very good agreement with experiment. Mode coupling of the water “antisymmetric” stretching mode with the low-frequency intermolecular modes results in intensity borrowing

[Study on the chemical constituents of Buddleja davidii].

Science.gov (United States)

Peng, Xue-Jing; Zeng, Yong; Luo, Jian-Jun; Chang, Xiao-Li; Xie, Qin-Jian; Wang, Ting; Li, Chong; Zhao, Lei

2012-12-01

To study the chemical constituents of Buddleja davidii. The constituents were isolated and purified by silica gel column chromatography, polyamide column chromatography and macroporous adsorption resin and their structures were identified by spectroscopic analysis. Eight compounds were elucidated as : Cranioside A (1), Eutigoside A (2), 1-O-4-Dimethoxyphenylethyl-4-O-3,4-dimethoxyphenylethy-beta-D-glucopyranoside (3), Isomartynoside (4'), 4"-O-Acetylmartynoside (5), Stigmasterol glueoside (6), beta-Sitosterol (7), Daucosterol (8). All these compounds are obtained from this plant for the first time.

Study of Cs adsorption on Ga(Mg)0.75Al0.25N (0 0 0 1) surface: A first principle calculation

International Nuclear Information System (INIS)

Yang, Mingzhu; Chang, Benkang; Hao, Guanghui; Guo, Jing; Wang, Honggang; Wang, Meishan

2013-01-01

In order to study the activation process of Ga 1−x Al x N photocathodes theoretically, models of Cs adsorption on Ga(Mg) 0.75 Al 0.25 N (0 0 0 1) surface are built, then the atomic structure, electronic structure, adsorption energy, work function, dipole moment and optical properties of the models are calculated. All calculations are carried out using Cambridge Serial Total Energy Package (CASTEP) based on first principle. Results show that Cs adsorption on Mg doping Ga 1−x Al x N (0 0 0 1) surface can reduce work function of the surface, and the favorite adsorption site is on the top of p-type impurity. Cs adsorption on p-type Ga 1−x Al x N (0 0 0 1) surface can produce the structure of p-type bulk with n-type surface, which is helpful to surface band bend downward and decrease electron affinity seriously. The absorption coefficient of Cs adsorption system is less than that of the clean surface. Theoretical study of Cs adsorption on Ga 1−x Al x N (0 0 0 1) surface can help to improve activation technology of Ga 1−x Al x N photocathodes.

To address surface reaction network complexity using scaling relations machine learning and DFT calculations

International Nuclear Information System (INIS)

Ulissi, Zachary W.; Medford, Andrew J.; Bligaard, Thomas; Nørskov, Jens K.

2017-01-01

Surface reaction networks involving hydrocarbons exhibit enormous complexity with thousands of species and reactions for all but the very simplest of chemistries. We present a framework for optimization under uncertainty for heterogeneous catalysis reaction networks using surrogate models that are trained on the fly. The surrogate model is constructed by teaching a Gaussian process adsorption energies based on group additivity fingerprints, combined with transition-state scaling relations and a simple classifier for determining the rate-limiting step. The surrogate model is iteratively used to predict the most important reaction step to be calculated explicitly with computationally demanding electronic structure theory. Applying these methods to the reaction of syngas on rhodium(111), we identify the most likely reaction mechanism. Lastly, propagating uncertainty throughout this process yields the likelihood that the final mechanism is complete given measurements on only a subset of the entire network and uncertainty in the underlying density functional theory calculations.

Study of the accuracy of radiation field calculations in media

International Nuclear Information System (INIS)

Bolyatko, V.V.; Vyrskij, M.Yu.; Ilyushkin, A.I.; Mashkovich, V.P.; Sakharov, V.K.; Stroganov, A.A.

1981-01-01

The sensitivity p of the radiation transport calculations to variations of input parameters Xsub(i) is theoretically analyzed, and the calculational errors induced by uncertainties of initial data are evaluated. Two calculational methods are considered: the direct substitution method using the ROZ-5 code and method using the linear perturbation theory. In order to calculate p(Xsub(i)) and bilinear convolutions of the conjugated transport equations the ZAKAT code has been developed. The calculations use the ZAKAT, ROZ-11 and APAMAKO-2F codes. As an example of practical use of the method proposed a shielding composition characteristic for fast reactors was analyzed. A plane monodirectional neutron beam of the BR-10 reactor falls onto a 5-layer stainless steel (1Kh18N10T)-carbon barrier. The sensitivily of the neutron dose absorbed in tissue to the cross sections of all the shielding constituents and to the source and detector representation functions has been calculated. A comparison of the calculations with experimental data proves the validity of the calculational method [ru

Efficient computer program EPAS-J1 for calculating stress intensity factors of three-dimensional surface cracks

International Nuclear Information System (INIS)

Miyazaki, Noriyuki; Watanabe, Takayuki; Yagawa, Genki.

1982-03-01

A finite element computer program EPAS-J1 was developed to calculate the stress intensity factors of three-dimensional cracks. In the program, the stress intensity factor is determined by the virtual crack extension method together with the distorted elements allocated along the crack front. This program also includes the connection elements based on the Lagrange multiplier concept to connect such different kinds of elements as the solid and shell elements, or the shell and beam elements. For the structure including three-dimensional surface cracks, the solid elements are employed only at the neighborhood of a surface crack, while the remainder of the structure is modeled by the shell or beam elements due to the reason that the crack singularity is very local. Computer storage and computational time can be highly reduced with the application of the above modeling technique for the calculation of the stress intensity factors of the three-dimensional surface cracks, because the three-dimensional solid elements are required only around the crack front. Several numerical analyses were performed by the EPAS-J1 program. At first, the accuracies of the connection element and the virtual crack extension method were confirmed using the simple structures. Compared with other techniques of connecting different kinds of elements such as the tying method or the method using anisotropic plate element, the present connection element is found to provide better results than the others. It is also found that the virtual crack extension method provides the accurate stress intensity factor. Furthermore, the results are also presented for the stress intensity factor analyses of cylinders with longitudinal or circumferential surface cracks using the combination of the various kinds of elements together with the connection elements. (author)

The effects of flow-path modification on water-quality constituent retention in an urban stormwater detention pond and wetland system, Orlando, Florida

Science.gov (United States)

Gain, W.S.

1996-01-01

Changes in constituent retention in a wet stormwater-detention pond and wetland system in Orlando, Florida, were evaluated following the 1988 installation of a flow barrier which approximately doubled the flow path and increased detention time in the pond. The pond and wetland were arranged in series so that stormwater first enters the pond and overflows into the wetland before spilling over to the regional stream system. Several principal factors that contribute to constituent retention were examined, including changes in pond-water quality between storms, stormwater quality, and pond-water flushing during storms. A simple, analytical pond-water mixing model was used as the basis for interpreting changes in retention efficiencies caused by pond modification. Retention efficiencies were calculated by a modified event-mean concentration efficiency method using a minimum variance unbiased estimator approach. The results of this study generally support the hypothesis that changes in the geometry of stormwater treatment systems can significantly affect the constituent retention efficiency of the pond and wetland system. However, the results also indicate that these changes in efficiency are caused not only by changes in residence time, but also by changes in stormwater mixing and pond water flushing during storms. Additionally, the use of average efficiencies as indications of treatment effectiveness may fail to account for biases associated with sample distribution and independent physical properties of the system, such as the range and concentrations of constituents in stormwater inflows and stormwater volume. Changes in retention efficiencies varied among chemical constituents and were significantly different in the pond and wetland. Retention efficiency was related to inflow concentration for most constituents. Increased flushing of the pond after modification caused decreases in retention efficiencies for constituents that concentrate in the pond between storms

The radiation environment on the surface of Mars - Summary of model calculations and comparison to RAD data.

Science.gov (United States)

Matthiä, Daniel; Hassler, Donald M; de Wet, Wouter; Ehresmann, Bent; Firan, Ana; Flores-McLaughlin, John; Guo, Jingnan; Heilbronn, Lawrence H; Lee, Kerry; Ratliff, Hunter; Rios, Ryan R; Slaba, Tony C; Smith, Michael; Stoffle, Nicholas N; Townsend, Lawrence W; Berger, Thomas; Reitz, Günther; Wimmer-Schweingruber, Robert F; Zeitlin, Cary

2017-08-01

The radiation environment at the Martian surface is, apart from occasional solar energetic particle events, dominated by galactic cosmic radiation, secondary particles produced in their interaction with the Martian atmosphere and albedo particles from the Martian regolith. The highly energetic primary cosmic radiation consists mainly of fully ionized nuclei creating a complex radiation field at the Martian surface. This complex field, its formation and its potential health risk posed to astronauts on future manned missions to Mars can only be fully understood using a combination of measurements and model calculations. In this work the outcome of a workshop held in June 2016 in Boulder, CO, USA is presented: experimental results from the Radiation Assessment Detector of the Mars Science Laboratory are compared to model results from GEANT4, HETC-HEDS, HZETRN, MCNP6, and PHITS. Charged and neutral particle spectra and dose rates measured between 15 November 2015 and 15 January 2016 and model results calculated for this time period are investigated. Copyright © 2017 The Committee on Space Research (COSPAR). All rights reserved.

Calculation of Operations Efficiency Factors for Mars Surface Missions

Science.gov (United States)

Laubach, Sharon

2014-01-01

The duration of a mission--and subsequently, the minimum spacecraft lifetime--is a key component in designing the capabilities of a spacecraft during mission formulation. However, determining the duration is not simply a function of how long it will take the spacecraft to execute the activities needed to achieve mission objectives. Instead, the effects of the interaction between the spacecraft and ground operators must also be taken into account. This paper describes a method, using "operations efficiency factors", to account for these effects for Mars surface missions. Typically, this level of analysis has not been performed until much later in the mission development cycle, and has not been able to influence mission or spacecraft design. Further, the notion of moving to sustainable operations during Prime Mission--and the effect that change would have on operations productivity and mission objective choices--has not been encountered until the most recent rover missions (MSL, the (now-cancelled) joint NASA-ESA 2018 Mars rover, and the proposed rover for Mars 2020). Since MSL had a single control center and sun-synchronous relay assets (like MER), estimates of productivity derived from MER prime and extended missions were used. However, Mars 2018's anticipated complexity (there would have been control centers in California and Italy, and a non-sun-synchronous relay asset) required the development of an explicit model of operations efficiency that could handle these complexities. In the case of the proposed Mars 2018 mission, the model was employed to assess the mission return of competing operations concepts, and as an input to component lifetime requirements. In this paper we provide examples of how to calculate the operations efficiency factor for a given operational configuration, and how to apply the factors to surface mission scenarios. This model can be applied to future missions to enable early effective trades between operations design, science mission

Calculations of oxide formation on low-index Cu surfaces

Energy Technology Data Exchange (ETDEWEB)

Lian, Xin; Liu, Renlong, E-mail: lrl@cqu.edu.cn, E-mail: henkelman@utexas.edu [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030 (China); Xiao, Penghao; Yang, Sheng-Che; Henkelman, Graeme, E-mail: lrl@cqu.edu.cn, E-mail: henkelman@utexas.edu [Department of Chemistry and the Institute for Computational and Engineering Sciences, University of Texas at Austin, Austin, Texas 78712-0165 (United States)

2016-07-28

Density-functional theory is used to evaluate the mechanism of copper surface oxidation. Reaction pathways of O{sub 2} dissociation on the surface and oxidation of the sub-surface are found on the Cu(100), Cu(110), and Cu(111) facets. At low oxygen coverage, all three surfaces dissociate O{sub 2} spontaneously. As oxygen accumulates on the surfaces, O{sub 2} dissociation becomes more difficult. A bottleneck to further oxidation occurs when the surfaces are saturated with oxygen. The barriers for O{sub 2} dissociation on the O-saturated Cu(100)-c(2×2)-0.5 monolayer (ML) and Cu(100) missing-row structures are 0.97 eV and 0.75 eV, respectively; significantly lower than those have been reported previously. Oxidation of Cu(110)-c(6×2), the most stable (110) surface oxide, has a barrier of 0.72 eV. As the reconstructions grow from step edges, clean Cu(110) surfaces can dissociatively adsorb oxygen until the surface Cu atoms are saturated. After slight rearrangements, these surface areas form a “1 ML” oxide structure which has not been reported in the literature. The barrier for further oxidation of this “1 ML” phase is only 0.31 eV. Finally the oxidized Cu(111) surface has a relatively low reaction energy barrier for O{sub 2} dissociation, even at high oxygen coverage, and allows for facile oxidation of the subsurface by fast O diffusion through the surface oxide. The kinetic mechanisms found provide a qualitative explanation of the observed oxidation of the low-index Cu surfaces.

The trapping of K and Na atoms by a clean W(110) surface. Dynamic trajectory calculations. ch.3

International Nuclear Information System (INIS)

Hurkmans, A.; Overbosch, E.G.; Los, J.

1976-01-01

The fraction of K and Na atoms which are initially trapped by a clean W(110) surface has been measured as a function of incident energy (0.5 < approximately Esub(i) < approximately 15 eV) at several angles of incidence. At the same time the desorption energies Qsub(i) of the trapped potassium and sodium atoms were measured: Qsub(i) = 2.05 +- 0.02 eV and Qsub(i) = 2.60 +- 0.04 eV respectively. The measured trapping probabilities can be described well by Trillings 'partially screened spherical cap' model, except fos the small angles of incidence. Dynamic trajectory calculations were performed for a particle scattered from a diatomic molecule to explain the screening and the descrepancy at normal incidence. The calculations give good quantitative agreement with the measured trapping probability at small angles both for potassium and sodium atoms and show that simultaneous interaction with two adjacent surface atoms affects the trapping particularly at small angles of incidence. (Auth.)

The radiation environment on the surface of Mars - Numerical calculations of the galactic component with GEANT4/PLANETOCOSMICS.

Science.gov (United States)

Matthiä, Daniel; Berger, Thomas

2017-08-01

Galactic cosmic radiation and secondary particles produced in the interaction with the atmosphere lead to a complex radiation field on the Martian surface. A workshop ("1st Mars Space Radiation Modeling Workshop") organized by the MSL-RAD science team was held in June 2016 in Boulder with the goal to compare models capable to predict this radiation field with each other and measurements from the RAD instrument onboard the curiosity rover taken between November 15, 2015 and January 15, 2016. In this work the results of PLANETOCOSMICS/GEANT4 contributed to the workshop are presented. Calculated secondary particle spectra on the Martian surface are investigated and the radiation field's directionality of the different particles in dependence on the energy is discussed. Omnidirectional particle fluxes are used in combination with fluence to dose conversion factors to calculate absorbed dose rates and dose equivalent rates in a slab of tissue. Copyright © 2017. Published by Elsevier Ltd.

Ab initio hybrid DFT calculations of BaTiO{sub 3}, PbTiO{sub 3}, SrZrO{sub 3} and PbZrO{sub 3} (111) surfaces

Energy Technology Data Exchange (ETDEWEB)

Eglitis, Roberts I., E-mail: rieglitis@gmail.com

2015-12-15

Highlights: • Surface energies for AO{sub 3}-term (111) surfaces are larger than for Ti (Zr)-term surfaces. • A increase of Ti−O (Zr−O) bond covalency near the ABO{sub 3} (111) surface relative to the bulk is observed. • The ABO{sub 3} (111) surface energy is larger than the earlier calculated (001) surface energy. • Band gap for PbTiO{sub 3}, SrZrO{sub 3} and PbZrO{sub 3} (111) surfaces becomes smaller, but for BaTiO{sub 3} (111) larger with respect to the bulk . - Abstract: The results of ab initio calculations for polar BaTiO{sub 3}, PbTiO{sub 3}, SrZrO{sub 3} and PbZrO{sub 3} (111) surfaces using the CRYSTAL code are presented. By means of the hybrid B3LYP approach, the surface relaxation has been calculated for two possible B (B = Ti or Zr) or AO{sub 3} (A = Ba, Pb or Sr) BaTiO{sub 3}, PbTiO{sub 3}, SrZrO{sub 3} and PbZrO{sub 3} (111) surface terminations. According to performed B3LYP calculations, all atoms of the first surface layer, for both terminations, relax inwards. The only exception is a small outward relaxation of the PbO{sub 3}-terminated PbTiO{sub 3} (111) surface upper layer Pb atom. B3LYP calculated surface energies for BaO{sub 3}, PbO{sub 3}, SrO{sub 3} and PbO{sub 3}-terminated BaTiO{sub 3}, PbTiO{sub 3}, SrZrO{sub 3} and PbZrO{sub 3} (111) surfaces are considerably larger than the surface energies for Ti (Zr)-terminated (111) surfaces. Performed B3LYP calculations indicate a considerable increase of Ti−O (Zr−O) chemical bond covalency near the BaTiO{sub 3}, PbTiO{sub 3}, SrZrO{sub 3} and PbZrO{sub 3} (111) surface relative to the BaTiO{sub 3}, PbTiO{sub 3}, SrZrO{sub 3} and PbZrO{sub 3} bulk. Calculated band gaps at the Γ-point near the PbTiO{sub 3}, SrZrO{sub 3} and PbZrO{sub 3} (111) surfaces are reduced, but near BaTiO{sub 3} (111) surfaces increased, with respect to the BaTiO{sub 3}, PbTiO{sub 3}, SrZrO{sub 3} and PbZrO{sub 3} bulk band gap at the Γ-point values.

[Chemical constituents from stems of Ilex pubescens].

Science.gov (United States)

Xing, Xian-dong; Zhang, Qian; Feng, Feng; Liu, Wen-yuan

2012-09-01

To study the chemical constituents from the stems of Ilex pubescens Hook. et Am. The chemical constituents were isolated and purified by various column chromatographic methods with diatomite, silica gel, ODS and Sephadex LH-20. Their structures were identified on physical properties and spectroscopic methods. Nine compounds were isolated and determined as luteolin(1), quercetin(2), hyperoside(3), rutin(4), 1, 5-dihydroxy-3-methyl-anthraquinone(5),3,5-dimethoxy-4-hydroxy-benzoic acid-1-O-beta-D-glucoside(6), hexadecanoic acid(7), stearic acid(8), n-tetratriacontanol(9), respectively. All the compounds are isolated from this plant for the first time, and compounds 5 and 6 are isolated from this genus for the first time.

Estimating instream constituent loads using replicate synoptic sampling, Peru Creek, Colorado

Science.gov (United States)

Runkel, Robert L.; Walton-Day, Katherine; Kimball, Briant A.; Verplanck, Philip L.; Nimick, David A.

2013-01-01

The synoptic mass balance approach is often used to evaluate constituent mass loading in streams affected by mine drainage. Spatial profiles of constituent mass load are used to identify sources of contamination and prioritize sites for remedial action. This paper presents a field scale study in which replicate synoptic sampling campaigns are used to quantify the aggregate uncertainty in constituent load that arises from (1) laboratory analyses of constituent and tracer concentrations, (2) field sampling error, and (3) temporal variation in concentration from diel constituent cycles and/or source variation. Consideration of these factors represents an advance in the application of the synoptic mass balance approach by placing error bars on estimates of constituent load and by allowing all sources of uncertainty to be quantified in aggregate; previous applications of the approach have provided only point estimates of constituent load and considered only a subset of the possible errors. Given estimates of aggregate uncertainty, site specific data and expert judgement may be used to qualitatively assess the contributions of individual factors to uncertainty. This assessment can be used to guide the collection of additional data to reduce uncertainty. Further, error bars provided by the replicate approach can aid the investigator in the interpretation of spatial loading profiles and the subsequent identification of constituent source areas within the watershed.The replicate sampling approach is applied to Peru Creek, a stream receiving acidic, metal-rich effluent from the Pennsylvania Mine. Other sources of acidity and metals within the study reach include a wetland area adjacent to the mine and tributary inflow from Cinnamon Gulch. Analysis of data collected under low-flow conditions indicates that concentrations of Al, Cd, Cu, Fe, Mn, Pb, and Zn in Peru Creek exceed aquatic life standards. Constituent loading within the study reach is dominated by effluent from the

Estimating instream constituent loads using replicate synoptic sampling, Peru Creek, Colorado

Science.gov (United States)

Runkel, Robert L.; Walton-Day, Katherine; Kimball, Briant A.; Verplanck, Philip L.; Nimick, David A.

2013-05-01

SummaryThe synoptic mass balance approach is often used to evaluate constituent mass loading in streams affected by mine drainage. Spatial profiles of constituent mass load are used to identify sources of contamination and prioritize sites for remedial action. This paper presents a field scale study in which replicate synoptic sampling campaigns are used to quantify the aggregate uncertainty in constituent load that arises from (1) laboratory analyses of constituent and tracer concentrations, (2) field sampling error, and (3) temporal variation in concentration from diel constituent cycles and/or source variation. Consideration of these factors represents an advance in the application of the synoptic mass balance approach by placing error bars on estimates of constituent load and by allowing all sources of uncertainty to be quantified in aggregate; previous applications of the approach have provided only point estimates of constituent load and considered only a subset of the possible errors. Given estimates of aggregate uncertainty, site specific data and expert judgement may be used to qualitatively assess the contributions of individual factors to uncertainty. This assessment can be used to guide the collection of additional data to reduce uncertainty. Further, error bars provided by the replicate approach can aid the investigator in the interpretation of spatial loading profiles and the subsequent identification of constituent source areas within the watershed. The replicate sampling approach is applied to Peru Creek, a stream receiving acidic, metal-rich effluent from the Pennsylvania Mine. Other sources of acidity and metals within the study reach include a wetland area adjacent to the mine and tributary inflow from Cinnamon Gulch. Analysis of data collected under low-flow conditions indicates that concentrations of Al, Cd, Cu, Fe, Mn, Pb, and Zn in Peru Creek exceed aquatic life standards. Constituent loading within the study reach is dominated by effluent

FreeSASA: An open source C library for solvent accessible surface area calculations [version 1; referees: 2 approved

Directory of Open Access Journals (Sweden)

Simon Mitternacht

2016-02-01

Full Text Available Calculating solvent accessible surface areas (SASA is a run-of-the-mill calculation in structural biology. Although there are many programs available for this calculation, there are no free-standing, open-source tools designed for easy tool-chain integration. FreeSASA is an open source C library for SASA calculations that provides both command-line and Python interfaces in addition to its C API. The library implements both Lee and Richards’ and Shrake and Rupley’s approximations, and is highly configurable to allow the user to control molecular parameters, accuracy and output granularity. It only depends on standard C libraries and should therefore be easy to compile and install on any platform. The library is well-documented, stable and efficient. The command-line interface can easily replace closed source legacy programs, with comparable or better accuracy and speed, and with some added functionality.

Thermodynamics and structure of liquid surfaces investigated directly with surface analytical tools

Energy Technology Data Exchange (ETDEWEB)

Andersson, Gunther [Flinders Univ., Adelaide, SA (Australia). Centre for NanoScale Science and Technology; Morgner, Harald [Leipzig Univ. (Germany). Wilhelm Ostwald Inst. for Physical and Theoretical Chemistry

2017-06-15

Measuring directly the composition, the distribution of constituents as function of the depth and the orientation of molecules at liquid surfaces is essential for determining physicochemical properties of liquid surfaces. While the experimental tools that have been developed for analyzing solid surfaces can in principal be applied to liquid surfaces, it turned out that they had to be adjusted to the particular challenges imposed by liquid samples, e.g. by the unavoidable vapor pressure and by the mobility of the constituting atoms/molecules. In the present work it is shown, how electron spectroscopy and ion scattering spectroscopy have been used for analyzing liquid surfaces. The emphasis of this review is on using the structural information gained for determining the physicochemical properties of liquid surfaces. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Analysis of gamma irradiated pepper constituents, 2

International Nuclear Information System (INIS)

Takagi, Kazuko; Ochiai, Junko; Okuyama, Tsuneo

1988-01-01

Black pepper, white pepper, frozen green pepper and real pink pepper (kept in vinegar) were analyzed by reversed phase IIPLC. The extraction method and HPLC conditions were same as the first report, that is, the extraction from pepper was performed by Automatic Air Hammer and the extracted samples were separated on a reversed phase C 8 column with a concave gradient from 0.1% trifluoro aceticacid (TFA) in water to 75% acetonitrile - 0.1% TFA in water for 60 minutes and detected at 210 nm, 280 nm. The different constituents were observed clearly on chromatogram between black pepper and white pepper. The different constituents were observed between different producing white peppers, and as the result that the analyzed pepper was distinguished its producing district by HPLC chromatogram. In order to investigate of effect of lyophilization on white pepper extracts, lyophilized extraction was analyzed by this HPLC method. Some peaks were decreased by lyophilization. The effect of heat on white pepper constituents was examined. White pepper was heated by electronic oven and thermostat. When the former method was used, decreased peak number (peak height was lower than without heat treatment) was more than latter method. These subtle change was able to be recognized by these HPLC chromatograms. (author)

[Advance in chemical constituents of genus Clematis].

Science.gov (United States)

Sun, Feng; Yang, Depo

2009-10-01

Progresses in the studies on chemical constituents of Clematis L. (belonging to the family Ranunculaceae) were systematiically reviewed in this article. The plants in this genus have a wide spectrum of constituents as follows: triterpenes, flavonoids, lignans, coumarins, alkaloids, volatile oils, steroids, organic acids, macrocyclic compounds and phenols, etc., among which triterpenoid saponins, flavonoids and lignans are the main components. The triterpenoid saponins are mainly oleanolic type and hederagenin type, most of which are bidesmosidic saponins, substituted with oligosaccharide chains at both C-3 and C-28, and some are substituted with acetyl, caffeoyl, isoferuloyl, p-methoxy cinnamyl and 3,4-dimethoxy cinnamyl groups in the oligosaccharide chains. The flavonoids from Clematis species are mainly flavones, flavonols, flavanones, isoflavones, xanthones and their glucosides (sugar moieties are connected to the aglycone through either the oxygen or the carbon atoms), the aglycones of which are mainly apigenin, kaempferol, luteolin and quercetin. The lignans from Clematis are mainly eupomatene lignans, cyclolignans, monoepoxylignans, bisepoxylignans and lignanolides. Clematis spp. are rich in resources, however, studies on their chemical constituents have only been carried out on twenty or so spp. As a result, it is necessary to expand our study on other spp. from this genus for better utilization of medicinal resources.

Apparatus and method for atmospheric pressure reactive atom plasma processing for shaping of damage free surfaces

Science.gov (United States)

Carr,; Jeffrey, W [Livermore, CA

2009-03-31

Fabrication apparatus and methods are disclosed for shaping and finishing difficult materials with no subsurface damage. The apparatus and methods use an atmospheric pressure mixed gas plasma discharge as a sub-aperture polisher of, for example, fused silica and single crystal silicon, silicon carbide and other materials. In one example, workpiece material is removed at the atomic level through reaction with fluorine atoms. In this example, these reactive species are produced by a noble gas plasma from trace constituent fluorocarbons or other fluorine containing gases added to the host argon matrix. The products of the reaction are gas phase compounds that flow from the surface of the workpiece, exposing fresh material to the etchant without condensation and redeposition on the newly created surface. The discharge provides a stable and predictable distribution of reactive species permitting the generation of a predetermined surface by translating the plasma across the workpiece along a calculated path.

[Chemical Constituents in hypoglycemic active fraction of Celastrus orbiculatus leaf].

Science.gov (United States)

Yu, Xiao-xia; Zhang, Ting-ting; Wang, Ding-yong

2014-06-01

To study the chemical constituents in the hypoglycemic active fraction of Celastrus orbiculatus leaf. The constituents were separated and purified by column chromatography and thin layer chromatography, and their structures were elucidated by IR, MS and NMR. Seven compounds were isolated from the active fraction of Celastnrus orbiculatus, which identified as kaempferol( 1) ,quercetin(2), kaempferol-7-0-α-L-rhamnoside (3), kaempferol-3,7-di-O-α-L-rhamnoside (4) , quercetin-3-0-β-D-glucoside(5), myricetrin(6) and kaempferol-3-0-rutinoside(7). Chemical constituents in the hypoglycemic active fraction of Celastrus orbiculatus leaf are reported for the first time,and compounds 5,6 and 7 are firstly obtained from this plant.

Volatile Constituents of Three Piper Species from Vietnam.

Science.gov (United States)

Hieua, Le D; Hoic, Tran M; Thangda, Tran D; Ogunwande, Isiaka A

2015-11-01

The chemical compositions of the essential oils obtained by hydrodistillation of three Piper plants grown in Vietnam are reported. The analysis was achieved by means of gas chromatography with flame ionization detection (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). The main constituents of the leaf oil of Piper majusculum Blume were β-caryophyllene (20.7%), germacrene D (18.6%) and β-elemene (11.3%). The quantitatively significant compounds of the volatile oils of P. harmandii C. DC were sabinene (leaves, 14.5%; stems, 16.2%), benzyl benzoate (leaves, 20.0%; stems, 29.40%) and benzyl salicylate (leaves, 14.1%; stems, 24.3%). Also, α-cadinol (17.0%) was identified in large proportion in the leaf oil. However, sabinene (leaves, 17.9%; stems, 13.5%), benzyl benzoate (leaves, 20.5%; stems, 32.5%) and β-eudesmol (leaves, 13.8%; stems, 8.4%) were the main constituents of P. brevicaule C. DC. This is the first report on the volatile constituents of both P. harmandii and P. brevicaule.

The effect of oxygen molecule adsorption on lead iodide perovskite surface by first-principles calculation

Science.gov (United States)

Ma, Xia-Xia; Li, Ze-Sheng

2018-01-01

Oxygen molecule has a negative effect on perovskite solar cells, which has been investigated experimentally. However, detailed theoretical research is still rare. This study presents a microscopic view to reveal the interaction mechanism between O2 and perovskite based on the first-principles calculation. The results show that O2 is adsorbed on the (100) surface of MAPbI3 perovskite mainly by Van der Waals force. O2 adsorption makes the MAPbI3 surface generate a small number of positive charges, which leads to the increase of the work function of the MAPbI3 surface. This is in agreement with the experimental measurement. And increased work function of MAPbI3 surface is not beneficial to electron transfer from perovskite to electronic extraction layer (such as TiO2). Comparison of the density of states (DOS) of the clean (100) surface and the adsorbed system shows that an in-gap state belonging to O2 appears, which can explain the phenomenon observed from experiments that electron transfers from the surface of perovskite to O2 to form superoxide. The theoretical power conversion efficiency of the system with and without O2 adsorption is evaluated, and it turns out that the power conversion efficiency of the system with O2 adsorption is slightly lower than that of the system without O2 adsorption. This result indicates that avoiding the introduction of O2 molecules between perovskite and electronic extraction layer is beneficial to the perovskite solar cell.

A fast calculating two-stream-like multiple scattering algorithm that captures azimuthal and elevation variations

Science.gov (United States)

Fiorino, Steven T.; Elmore, Brannon; Schmidt, Jaclyn; Matchefts, Elizabeth; Burley, Jarred L.

2016-05-01

Properly accounting for multiple scattering effects can have important implications for remote sensing and possibly directed energy applications. For example, increasing path radiance can affect signal noise. This study describes the implementation of a fast-calculating two-stream-like multiple scattering algorithm that captures azimuthal and elevation variations into the Laser Environmental Effects Definition and Reference (LEEDR) atmospheric characterization and radiative transfer code. The multiple scattering algorithm fully solves for molecular, aerosol, cloud, and precipitation single-scatter layer effects with a Mie algorithm at every calculation point/layer rather than an interpolated value from a pre-calculated look-up-table. This top-down cumulative diffusivity method first considers the incident solar radiance contribution to a given layer accounting for solid angle and elevation, and it then measures the contribution of diffused energy from previous layers based on the transmission of the current level to produce a cumulative radiance that is reflected from a surface and measured at the aperture at the observer. Then a unique set of asymmetry and backscattering phase function parameter calculations are made which account for the radiance loss due to the molecular and aerosol constituent reflectivity within a level and allows for a more accurate characterization of diffuse layers that contribute to multiple scattered radiances in inhomogeneous atmospheres. The code logic is valid for spectral bands between 200 nm and radio wavelengths, and the accuracy is demonstrated by comparing the results from LEEDR to observed sky radiance data.

Antioxidant and antibacterial constituents of Steganotaenia ...

African Journals Online (AJOL)

GC-MS analysis of the hexane and dichloromethane was carried out to determine their chemical constituents. Results revealed that both extracts contained similar compounds (including cumene, xylene, citronellol and long chain hydrocarbons). In addition the dichloromethane extract contains cadinanol, ar-curcumene and ...

Anisotropic scattering effect in calculations of nuclear reactor cells by the surface preseudosource method

International Nuclear Information System (INIS)

Laletin, N.I.; Sultanov, N.V.; Boyarinov, V.F.

1992-01-01

Estimation is fulfilled of an influence of scattering anisotropy on K ef the TRX and BAPL assemblies by the WIMS-D4 program in the transport (TA) and linear-anisotropic (LAA) approximations. It is shown that account for the scattering anisotropy in the LAA in comparison with TA decreases K ef by 0.8% for TRX assemblies and by 0.5-0.6% for BAPL ones. For more detailed account for the scattering anisotropy in calculations of cylindrical and cluster cells in the one-velocity approximation is developed a technique for account for the anisotropy in the methods of surface pseudosources

Kinetic-energy functionals studied by surface calculations

DEFF Research Database (Denmark)

Vitos, Levente; Skriver, Hans Lomholt; Kollár, J.

1998-01-01

The self-consistent jellium model of metal surfaces is used to study the accuracy of a number of semilocal kinetic-energy functionals for independent particles. It is shown that the poor accuracy exhibited by the gradient expansion approximation and most of the semiempirical functionals in the lo...... density, high gradient limit may be subtantially improved by including locally a von Weizsacker term. Based on this, we propose a simple one-parameter Pade's approximation, which reproduces the exact Kohn-Sham surface kinetic energy over the entire range of metallic densities....

Thermodynamic data of water on smectite surface and those applications to swelling pressure of compacted bentonite

International Nuclear Information System (INIS)

Sato, H.

2009-01-01

Swelling pressure was discussed focusing on the thermodynamic properties of water on smectite (montmorillonite) which is the major clay mineral constituent of the bentonite buffer. The thermodynamic data of the water on the smectite surface were obtained as a function of water content and temperature in a range of dry density 0.6-0.9 Mg/m 3 . Purified Na-smectite of which all interlayer cations were exchanged with Na+ ions, was used. The activity (a H 2 O ) and the relative partial molar Gibbs free energy (ΔG H 2 O ) of the water were obtained at 25 C. Both a H 2 O and ΔG H 2 O decreased with a decrease of water content, and similar results were obtained to data reported for montmorillonite (Kunipia-F bentonite). Since the specific surface area of smectite is about 800 m 2 /g, water up to approximately 2 water layers from smectite surface is thermodynamically evaluated to be bound. Swelling pressure versus smectite partial density was calculated based on ΔG H 2 O and compared to data experimentally obtained for various kinds of bentonites. The calculated results were in good agreement with the measured data over the range of smectite partial density between 1.0 and 2.0 Mg/m 3 . (author)

First-principles calculation of adsorption of shale gas on CaCO3 (100) surfaces.

Science.gov (United States)

Luo, Qiang; Pan, Yikun; Guo, Ping; Wang, Zhouhua; Wei, Na; Sun, Pengfei; Liu, Yuxiao

2017-06-16

To demonstrate the adsorption strength of shale gas to calcium carbonate in shale matrix, the adsorption of shale gas on CaCO3 (100) surfaces was studied using the first-principles method, which is based on the density functional theory (DFT). The structures and electronic properties of CH4, C2H6, CO2 and N2 molecules were calculated by the generalized gradient approximation (GGA), for a coverage of 1 monolayer (ML). Under the same conditions, the density of states (DOS) of CaCO3 (100) surfaces before and after the adsorption of shale gas molecules at high-symmetry adsorption sites were compared. The results showed that the adsorption energies of CH4, C2H6, CO2 and N2 on CaCO3 (100) surfaces were between 0.2683 eV and -0.7388 eV. When a CH4 molecule was adsorbed at a hollow site and its 2 hydrogen atoms were parallel to the long diagonal (H3) on the CaCO3 (100) surface, it had the most stable adsorption, and the adsorption energy was only -0.4160 eV. The change of adsorption energy of CH4 was no more than 0.0535 eV. Compared with the DOS distribution of CH4 before adsorption, it shifted to the left overall after adsorption. At the same time, the partial density of states (PDOS) curves of CaCO3 (100) surfaces before and after adsorption basically overlapped. This work showed that the adsorption effect of shale gas on calcium carbonate is very weak, and the adsorption is physisorption at the molecular level.

Determination of major aromatic constituents in vanilla using an on-line supercritical fluid extraction coupled with supercritical fluid chromatography.

Science.gov (United States)

Liang, Yanshan; Liu, Jiaqi; Zhong, Qisheng; Shen, Lingling; Yao, Jinting; Huang, Taohong; Zhou, Ting

2018-04-01

An on-line supercritical fluid extraction coupled with supercritical fluid chromatography method was developed for the determination of four major aromatic constituents in vanilla. The parameters of supercritical fluid extraction were systematically investigated using single factor optimization experiments and response surface methodology by a Box-Behnken design. The modifier ratio, split ratio, and the extraction temperature and pressure were the major parameters which have significant effects on the extraction. While the static extraction time, dynamic extraction time, and recycle time had little influence on the compounds with low polarity. Under the optimized conditions, the relative extraction efficiencies of all the constituents reached 89.0-95.1%. The limits of quantification were in the range of 1.123-4.747 μg. The limits of detection were in the range of 0.3368-1.424 μg. The recoveries of the four analytes were in the range of 76.1-88.9%. The relative standard deviations of intra- and interday precision ranged from 4.2 to 7.6%. Compared with other off-line methods, the present method obtained higher extraction yields for all four aromatic constituents. Finally, this method has been applied to the analysis of vanilla from different sources. On the basis of the results, the on-line supercritical fluid extraction-supercritical fluid chromatography method shows great promise in the analysis of aromatic constituents in natural products. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Surface excitation parameter for rough surfaces

International Nuclear Information System (INIS)

Da, Bo; Salma, Khanam; Ji, Hui; Mao, Shifeng; Zhang, Guanghui; Wang, Xiaoping; Ding, Zejun

2015-01-01

Graphical abstract: - Highlights: • Instead of providing a general mathematical model of roughness, we directly use a finite element triangle mesh method to build a fully 3D rough surface from the practical sample. • The surface plasmon excitation can be introduced to the realistic sample surface by dielectric response theory and finite element method. • We found that SEP calculated based on ideal plane surface model are still reliable for real sample surface with common roughness. - Abstract: In order to assess quantitatively the importance of surface excitation effect in surface electron spectroscopy measurement, surface excitation parameter (SEP) has been introduced to describe the surface excitation probability as an average number of surface excitations that electrons can undergo when they move through solid surface either in incoming or outgoing directions. Meanwhile, surface roughness is an inevitable issue in experiments particularly when the sample surface is cleaned with ion beam bombardment. Surface roughness alters not only the electron elastic peak intensity but also the surface excitation intensity. However, almost all of the popular theoretical models for determining SEP are based on ideal plane surface approximation. In order to figure out whether this approximation is efficient or not for SEP calculation and the scope of this assumption, we proposed a new way to determine the SEP for a rough surface by a Monte Carlo simulation of electron scattering process near to a realistic rough surface, which is modeled by a finite element analysis method according to AFM image. The elastic peak intensity is calculated for different electron incident and emission angles. Assuming surface excitations obey the Poisson distribution the SEPs corrected for surface roughness are then obtained by analyzing the elastic peak intensity for several materials and for different incident and emission angles. It is found that the surface roughness only plays an

Surface incompressibility from semiclassical relativistic mean field calculations

International Nuclear Information System (INIS)

Patra, S.K.; Centelles, M.; Vinas, X.; Estal, M. del

2002-01-01

By using the scaling method and the Thomas-Fermi and extended Thomas-Fermi approaches to relativistic mean field theory the surface contribution to the leptodermous expansion of the finite nuclei incompressibility K A has been self-consistently computed. The validity of the simplest expansion, which contains volume, volume-symmetry, surface, and Coulomb terms, is examined by comparing it with self-consistent results of K A for some currently used nonlinear σ-ω parameter sets. A numerical estimate of higher-order contributions to the leptodermous expansion, namely, the curvature and surface-symmetry terms, is made

40 CFR 227.6 - Constituents prohibited as other than trace contaminants.

Science.gov (United States)

2010-07-01

... trace contaminants. 227.6 Section 227.6 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Environmental Impact § 227.6 Constituents prohibited as other than trace contaminants. (a) Subject to the..., of materials containing the following constituents as other than trace contaminants will not be...

40 CFR 63.5752 - How do I calculate the organic HAP content of aluminum recreational boat surface coatings?

Science.gov (United States)

2010-07-01

... Manufacturing Standards for Aluminum Recreational Boat Surface Coating Operations § 63.5752 How do I calculate... fraction of organic HAP in coating i, kilograms of organic HAP per kilogram of coating. p = number of..., activator, or additive k, kilograms per liter. Wk= mass fraction of organic HAP in thinner, activator, or...

Soil heat flux calculation for sunlit and shaded surfaces under row crops: 1 - Model Development and sensitivity analysis

Science.gov (United States)

Soil heat flux at the surface (G0) is strongly influenced by whether the soil is shaded or sunlit, and therefore can have large spatial variability for incomplete vegetation cover, such as across the interrows of row crops. Most practical soil-plant-atmosphere energy balance models calculate G0 as a...

Identifying constituents in commercial gasoline using Fourier transform-infrared spectroscopy and independent component analysis.

Science.gov (United States)

Pasadakis, Nikos; Kardamakis, Andreas A

2006-09-25

A new method is proposed that enables the identification of five refinery fractions present in commercial gasoline mixtures using infrared spectroscopic analysis. The data analysis and interpretation was carried out based on independent component analysis (ICA) and spectral similarity techniques. The FT-IR spectra of the gasoline constituents were determined using the ICA method, exclusively based on the spectra of their mixtures as a blind separation procedure, i.e. assuming unknown the spectra of the constituents. The identity of the constituents was subsequently determined using similarity measures commonly employed in spectra library searches against the spectra of the constituent components. The high correlation scores that were obtained in the identification of the constituents indicates that the developed method can be employed as a rapid and effective tool in quality control, fingerprinting or forensic applications, where gasoline constituents are suspected.

40 CFR 227.7 - Limits established for specific wastes or waste constituents.

Science.gov (United States)

2010-07-01

..., shellfish and wildlife by: (1) Extending the range of biological pests, viruses, pathogenic microorganisms... containing biodegradable constituents, or constituents which consume oxygen in any fashion, may be dumped in...

[Chemical constituents of the roots of Vaccinium bracteatum].

Science.gov (United States)

Lv, Xiao-Lan; Mai, Xi; Guo, Hui; Lai, Xiao-Ping

2012-06-01

To study the chemical constituents of the roots of Vaccinium bracteatum. The constituents were separated and purified with chromatographic methods (including silica gel, Sephadex LH-20 and RP-18 column chromatography), and their structures were determined by spectroscopic methods (including MS, 1H-NMR and 13C-NMR). 10 compounds were isolated from the roots of Vaccinium bracteatu and were elucidated as chlorogenic acid (1), pinoresinol (2), ferulic acid (3), kaempferol (4), trans-caffeic acid (5), beta-sitosterol (6), quercetin (7), oleanolic acid (8), apigenin (9) and luteolin (10). Compounds 1 -3 are obtained from this plant for the first time.

CYTOTOXIC ACTIVITY OF THE CONSTITUENTS OF ...

African Journals Online (AJOL)

Crude methanol extracts obtained from the stem, roots and leaves of Anthocleista djalonensis and three natural plant constituents (djalonenol 1, sweroside 3 and djalonensone 9 respectively) isolated from these extracts were evaluated invitro against ST-57 brain tumor transformed fibroblasts. In addition, six semisynthetic ...

Calculated fission properties of the heaviest elements

International Nuclear Information System (INIS)

Moeller, P.; Nix, J.R.; Swiatecki, W.J.

1986-09-01

A quantitative calculation is presented that shows where high-kinetic-energy symmetric fission occurs and why it is associated with a sudden and large decrease in fission half-lives. The study is based on calculations of potential-energy surfaces in the macroscopic-microscopic model and a semi-empirical model for the nuclear inertia. For the macroscopic part a Yukawa-plus-exponential model is used and for the microscopic part a folded-Yukawa single-particle potential is used. The three-quadratic-surface parameterization generates shapes for which the potential-energy surfaces are calculated. The use of this parameterization and the use of the finite-range macroscopic model allows for the study of two touching spheres and similar shapes. The results of the calculations in terms of potential-energy surfaces and fission half-lives are presented for heavy even nuclei. The surfaces are displayed in the form of contour diagrams as functions of two moments of the shape. 53 refs., 15 figs., 1 tab

Methods of using adsorption media for separating or removing constituents

Science.gov (United States)

Tranter, Troy J [Idaho Falls, ID; Herbst, R Scott [Idaho Falls, ID; Mann, Nicholas R [Blackfoot, ID; Todd, Terry A [Aberdeen, ID

2011-10-25

Methods of using an adsorption medium to remove at least one constituent from a feed stream. The method comprises contacting an adsorption medium with a feed stream comprising at least one constituent and removing the at least one constituent from the feed stream. The adsorption medium comprises a polyacrylonitrile (PAN) matrix and at least one metal hydroxide homogenously dispersed therein. The adsorption medium may comprise from approximately 15 wt % to approximately 90 wt % of the PAN and from approximately 10 wt % to approximately 85 wt % of the at least one metal hydroxide. The at least one metal hydroxide may be selected from the group consisting of ferric hydroxide, zirconium hydroxide, lanthanum hydroxide, cerium hydroxide, titanium hydroxide, copper hydroxide, antimony hydroxide, and molybdenum hydroxide.

Calculating the Jc, B, T surface for commercial niobium tin conductors using a reduced state model

International Nuclear Information System (INIS)

Green, M.A.

1993-07-01

This report presents a method for calculating the J c , B, T critical surface for commercial grade niobium tin given an effective T c and B c2 and J c over a range of magnetic inductions B. Given the effective T c and B c2 and J c , one can estimate the J c over a range of magnetic inductions from 0.1 T to 0.8 times effective B c2 and a range of temperatures from 1.5 K to about 14 K. The effects of conductor strain can also be estimated using the method. A comparison between calculated values of J c and measurements is illustrated for a number of cases. The method presented in this report can be used to estimate the performance of niobium tin in magnets at temperatures different from those where measured data is available. The method of calculating the J c can also be used to estimate the effects of superconductor magnetization on the field quality at low fields

Analytical Techniques and Pharmacokinetics of Gastrodia elata Blume and Its Constituents.

Science.gov (United States)

Wu, Jinyi; Wu, Bingchu; Tang, Chunlan; Zhao, Jinshun

2017-07-08

Gastrodia elata Blume ( G. elata ), commonly called Tianma in Chinese, is an important and notable traditional Chinese medicine (TCM), which has been used in China as an anticonvulsant, analgesic, sedative, anti-asthma, anti-immune drug since ancient times. The aim of this review is to provide an overview of the abundant efforts of scientists in developing analytical techniques and performing pharmacokinetic studies of G. elata and its constituents, including sample pretreatment methods, analytical techniques, absorption, distribution, metabolism, excretion (ADME) and influence factors to its pharmacokinetics. Based on the reported pharmacokinetic property data of G. elata and its constituents, it is hoped that more studies will focus on the development of rapid and sensitive analytical techniques, discovering new therapeutic uses and understanding the specific in vivo mechanisms of action of G. elata and its constituents from the pharmacokinetic viewpoint in the near future. The present review discusses analytical techniques and pharmacokinetics of G. elata and its constituents reported from 1985 onwards.

[Analysis of the chemical constituents of volatile oils of Metasequoia glyptostroboides leave].

Science.gov (United States)

Shong, E; Lui, R

1997-10-01

The chemical constituents of volatile oils of Metasequoia glyptostroboides leave were analyzed by GC-MS-DS. 27 constituents were identified, alpha-pinene (70.65%) and caryophyllene (10.38%) of them are main components.

Transformations of inorganic coal constituents in combustion systems

Energy Technology Data Exchange (ETDEWEB)

Helble, J.J. (ed.); Srinivasachar, S.; Wilemski, G.; Boni, A.A. (PSI Technology Co., Andover, MA (United States)); Kang, Shin-Gyoo; Sarofim, A.F.; Graham, K.A.; Beer, J.M. (Massachusetts Inst. of Tech., Cambridge, MA (United States)); Peterson, T.W.; Wendt, J.O.L.; Gallagher, N.B.; Bool, L. (Arizona Univ., Tucson, AZ (United States)); Huggins, F.E.; Huffman, G.P.; Shah, N.; Shah, A. (Kentucky Univ., Lexingt

1992-11-01

The inorganic constituents or ash contained in pulverized coal significantly increase the environmental and economic costs of coal utilization. For example, ash particles produced during combustion may deposit on heat transfer surfaces, decreasing heat transfer rates and increasing maintenance costs. The minimization of particulate emissions often requires the installation of cleanup devices such as electrostatic precipitators, also adding to the expense of coal utilization. Despite these costly problems, a comprehensive assessment of the ash formation and had never been attempted. At the start of this program, it was hypothesized that ash deposition and ash particle emissions both depended upon the size and chemical composition of individual ash particles. Questions such as: What determines the size of individual ash particles What determines their composition Whether or not particles deposit How combustion conditions, including reactor size, affect these processes remained to be answered. In this 6-year multidisciplinary study, these issues were addressed in detail. The ambitious overall goal was the development of a comprehensive model to predict the size and chemical composition distributions of ash produced during pulverized coal combustion. Results are described.

Priority pollutants and associated constituents in untreated and treated discharges from coal mining or processing facilities in Pennsylvania, USA

Science.gov (United States)

Cravotta, III, Charles A.; Brady, Keith B.C.

2015-01-01

Clean sampling and analysis procedures were used to quantify more than 70 inorganic constituents, including 35 potentially toxic or hazardous constituents, organic carbon, and other characteristics of untreated (influent) and treated (effluent) coal-mine discharges (CMD) at 38 permitted coal-mining or coal-processing facilities in the bituminous coalfield and 4 facilities in the anthracite coalfield of Pennsylvania. Of the 42 facilities sampled during 2011, 26 were surface mines, 11 were underground mines, and 5 were coal refuse disposal operations. Treatment of CMD with caustic soda (NaOH), lime (CaO or Ca(OH)2), flocculent, or limestone was ongoing at 21%, 40%, 6%, and 4% of the facilities, respectively; no chemicals were added at the remaining facilities. All facilities with CMD treatment incorporated structures for active or passive aeration and settling of metal-rich precipitate.

Absorption mechanism of three curcumin constituents through in situ intestinal perfusion method

Directory of Open Access Journals (Sweden)

Y.-H. Wang

2017-09-01

Full Text Available This study aimed to investigate the absorption mechanism of three curcumin constituents in rat small intestines. Self-emulsification was used to solubilize the three curcumin constituents, and the rat in situ intestinal perfusion method was used to study factors on drug absorption, including drug mass concentration, absorption site, and the different types and concentrations of absorption inhibitors. Within the scope of experimental concentrations, three curcumin constituents were absorbed in rat small intestines through the active transport mechanism.

Methods for the calculation of derived working limits for surface contamination by low-toxicity radionuclides

International Nuclear Information System (INIS)

Gibson, J.A.B.; Wrixon, A.D.

1979-01-01

Surface contamination is often measured as an indication of the general spread of radioactive contamination in a particular place. Derived working limits, (DWLs) for surface contamination provide figures against which to assess the significance of measurements. Derived working limits for surface contamination were first established for use in the nuclear energy industry. They were designed to cope with a wide range of unspecified radionuclides and were therefore based on the assumption that the contamination was due to the presence of the most hazardous radionuclides, e.g. 90 Sr, 210 Pb, 226 Ra and 239 Pu. While this assumption may still be appropriate when the radionuclide mixture is unknown, there are now many specialized uses of particular low-toxicity radionuclides in universities, hospitals and general industry. If it is known that only a particular radionuclide is present, the general DWL can be replaced by a more specific value. The methods for calculating DWLs for some of the more commonly employed low-toxicity radionuclides are described. The exposure pathways considered are (a) external radiation of the skin and inhalation of airborne material from contaminated surfaces in active areas; (b) external irradiation of the skin and ingestion from contaminated skin. Some consideration is given to the effect of the revised dose equivalent limits in the most recent recommendations of ICRP. (author)

Surface study of gallium- and aluminum- doped graphenes upon adsorption of cytosine: DFT calculations

International Nuclear Information System (INIS)

Shokuhi Rad, Ali; Zareyee, Daryoush; Peyravi, Majid; Jahanshahi, Mohsen

2016-01-01

Highlights: • P1 and P4 are the most stable adsorption configurations for cytosine. • NBO analysis show n-type semiconductor property for both Al- and Ga-doped graphenes. • Important changes in the HOMO and LUMO of doped graphene upon adsorption of cytosine. • Increase in the conductivity of system when cytosine is adsorbed on doped graphenes. - Abstract: The adsorption of cytosine molecule on Al- and Ga- doped graphenes is studied using first-principles density functional theory (DFT) calculations. The energetically most stable geometries of cytosine on both Al- and Ga- doped graphenes are determined and the adsorption energies are calculated. The net charge of transfer as well as local charge of doped atoms upon adsorption of cytosine are studied by natural bond orbitals (NBO) analysis. Orbital hybridizing of complexes was searched by frontier molecular orbital theory (FMO), and density of states (DOS). Depending on the side of cytosine, there are four possible sites for its adsorption on doped graphene; denoted as P1, P2, P3, and P4, respectively. The order of binding energy in the case of Al-doped graphene is found as P1 > P4 > P3 > P2. Interestingly, the order in the case of Ga-doped graphene changes to: P4 ∼ P1 > P3 > P2. Both surfaces show superior adsorbent property, resulting chemisorption of cytosine, especially at P1 and P4 position configurations. The NBO charge analysis reveals that the charge transfers from Al- and Ga- doped graphene sheets to cytosine. The electronic properties of both surfaces undertake important changes after cytosine adsorption, which indicates notable change in its electrical conductivity.

Surface study of gallium- and aluminum- doped graphenes upon adsorption of cytosine: DFT calculations

Energy Technology Data Exchange (ETDEWEB)

Shokuhi Rad, Ali, E-mail: a.shokuhi@gmail.com [Department of Chemical Engineering, Qaemshahr Branch, Islamic Azad University, Qaemshahr (Iran, Islamic Republic of); Zareyee, Daryoush [Department of Chemistry, Qaemshahr Branch, Islamic Azad University, Qaemshahr (Iran, Islamic Republic of); Peyravi, Majid; Jahanshahi, Mohsen [Faculty of Chemical Engineering, Babol University of Technology, Babol (Iran, Islamic Republic of)

2016-12-30

Highlights: • P1 and P4 are the most stable adsorption configurations for cytosine. • NBO analysis show n-type semiconductor property for both Al- and Ga-doped graphenes. • Important changes in the HOMO and LUMO of doped graphene upon adsorption of cytosine. • Increase in the conductivity of system when cytosine is adsorbed on doped graphenes. - Abstract: The adsorption of cytosine molecule on Al- and Ga- doped graphenes is studied using first-principles density functional theory (DFT) calculations. The energetically most stable geometries of cytosine on both Al- and Ga- doped graphenes are determined and the adsorption energies are calculated. The net charge of transfer as well as local charge of doped atoms upon adsorption of cytosine are studied by natural bond orbitals (NBO) analysis. Orbital hybridizing of complexes was searched by frontier molecular orbital theory (FMO), and density of states (DOS). Depending on the side of cytosine, there are four possible sites for its adsorption on doped graphene; denoted as P1, P2, P3, and P4, respectively. The order of binding energy in the case of Al-doped graphene is found as P1 > P4 > P3 > P2. Interestingly, the order in the case of Ga-doped graphene changes to: P4 ∼ P1 > P3 > P2. Both surfaces show superior adsorbent property, resulting chemisorption of cytosine, especially at P1 and P4 position configurations. The NBO charge analysis reveals that the charge transfers from Al- and Ga- doped graphene sheets to cytosine. The electronic properties of both surfaces undertake important changes after cytosine adsorption, which indicates notable change in its electrical conductivity.

Multi-satellite ocean tide modelling - the K-1 constituent

DEFF Research Database (Denmark)

Andersen, Ole Baltazar; Knudsen, Per

1997-01-01

All major ocean tide constituents are aliased into signals with periods less than 90 days from TOPEX/POSEIDON altimetry, except the K-1 constituent. The aliased K-1 has a period of 173 days. Consequently, it might be confounded with height variations caused by the semiannual cycle having a period......, where the presence of crossing tracks cannot separate K-1 from the semiannual signal from TOPEX/POSEIDON, the importance of including ERS-1 and GEOSAT observations was demonstrated. A comparison with 29 pelagic and coastal tide gauges in the Southern Ocean south of 50 degrees S gave 5.59 (M-2), 2.27 (S......-2) and 5.04 (K-1) cm RMS agreement for FES95.1 ocean tide model. The same comparison for the best empirical estimated constituents based on TOPEX/POSEIDON + ERS-1 + GEOSAT gave 4.32, 2.21, and 4.29 cm for M-2, S-2 and K-1, respectively....

Surface water management: a user's guide to calculate a water balance using the CREAMS model

International Nuclear Information System (INIS)

Lane, L.J.

1984-11-01

The hydrologic component of the CREAMS model is described and discussed in terms of calculating a surface water balance for shallow land burial systems used for waste disposal. Parameter estimates and estimation procedures are presented in detail in the form of a user's guide. Use of the model is illustrated with three examples based on analysis of data from Los Alamos, New Mexico and Rock Valley, Nevada. Use of the model in design of trench caps for shallow land burial systems is illustrated with the example applications at Los Alamos

Coriander (Coriandrum sativum L.) and its bioactive constituents.

Science.gov (United States)

Laribi, Bochra; Kouki, Karima; M'Hamdi, Mahmoud; Bettaieb, Taoufik

2015-06-01

Coriander (Coriandrum sativum L.), a member of the Apiaceae family, is among most widely used medicinal plant, possessing nutritional as well as medicinal properties. Thus, the aim of this updated review is to highlight the importance of coriander as a potential source of bioactive constituents and to summarize their biological activities as well as their different applications from data obtained in recent literature, with critical analysis on the gaps and potential for future investigations. A literature review was carried out by searching on the electronic databases including PubMed, Scopus, ScienceDirect, and Google Scholar for studies focusing on the biological and pharmacological activities of coriander seed and herb bioactive constituents. All recent English-language articles published between 2000 and 2014 were searched using the terms 'C. sativum', 'medicinal plant', 'bioactive constituents', and 'biological activities'. Subsequently, coriander seed and herb essential oils have been actively investigated for their chemical composition and biological activities including antimicrobial, antioxidant, hypoglycemic, hypolipidemic, anxiolytic, analgesic, anti-inflammatory, anti-convulsant and anti-cancer activities, among others. Although coriander has been reported to possess a wide range of traditional medicinal uses, no report is available in its effectiveness use in reactive airway diseases such as asthma and bronchiolitis. In brief, the information presented herein will be helpful to create more interest towards this medicinal species by defining novel pharmacological and clinical applications and hence, may be useful in developing new drug formulations in the future or by employing coriander bioactive constituents in combination with conventional drugs to enhance the treatment of diseases such as Alzheimer and cancer. Copyright © 2015 Elsevier B.V. All rights reserved.

Surface phonons and elastic surface waves

Science.gov (United States)

Büscher, H.; Klein-Heßling, W.; Ludwig, W.

Theoretical investigations on the dynamics of the (001), (110) and (111) surfaces of some cubic metals (Ag, Cu, Ni) will be reviewed. Both, lattice dynamical and continuum theoretical results are obtained via a Green's function formalism. The main attitude of this paper is the comparison of our results with experiments and with results obtained via slab-calculations. The calculation of elastic surface waves has been performed using a modified surface-green-function-matching method. We have used two different approaches of calculation the bulk Green's function (a) using the spectral representation and (b) a method, what works on residues. The investigations are carried out using shortrange phenomenological potentials. The atomic force constants in the first surface layers are modified to describe surface phonon anomalies, observed by experiments. In the case of Ag (100) and Ag(110) we conclude that the detection of odd symmetry shear modes by Erskine et al. [1 a, b] was not very accurate.

Surface phonons and elastic surface waves

International Nuclear Information System (INIS)

Buescher, H.; Klein-Hessling, W.; Ludwig, W.

1993-01-01

Theoretical investigations on the dynamics of the (001), (110) and (111) surfaces of some cubic metals (Ag, Cu, Ni) will be reviewed. Both, lattice dynamical and continuum theoretical results are obtained via a Green's function formalism. The main attitude of this paper is the comparison of our results with experiments and with results obtained via slab-calculations. The calculation of elastic surface waves has been performed using a modified surface-green-function-matching method. We have used two different approaches of calculation the bulk Green's function (a) using the spectral representation and (b) a method, what works on residues. The investigations are carried out using shortrange phenomenological potentials. The atomic force constants in the first surface layers are modified to describe surface phonon anomalies, observed by experiments. In the case of Ag(100) and Ag(110) we conclude that the detection of odd symmetry shear modes by Erskine et al. was not very accurate. (orig.)

Calculation of the Arc Velocity Along the Polluted Surface of Short Glass Plates Considering the Air Effect

Directory of Open Access Journals (Sweden)

Tao Yuan

2012-03-01

Full Text Available To investigate the microphysics mechanism and the factors that influence arc development along a polluted surface, the arc was considered as a plasma fluid. Based on the image method and the collision ionization theory, the electric field of the arc needed to maintain movement with different degrees of pollution was calculated. According to the force of the charged particle in an arc plasma stressed under an electric field, a calculation model of arc velocity, which is dependent on the electric field of the arc head that incorporated the effects of airflow around the electrode and air resistance is presented. An experiment was carried out to measure the arc velocity, which was then compared with the calculated value. The results of the experiment indicated that the lighter the pollution is, the larger the electric field of the arc head and arc velocity is; when the pollution is heavy, the effect of thermal buoyancy that hinders arc movement increases, which greatly reduces the arc velocity.

Classical relativistic constituent particles and composite-particle scattering

International Nuclear Information System (INIS)

King, M.J.

1984-01-01

A nonlocal Lagrangian formalism is developed to describe a classical many-particle system. The nonstandard Lagrangian is a function of a single parameter s which is not, in general, associated with the physical clock. The particles are constrained to be constituents of composite systems, which in turn can decompose into asymptotic composite states representing free observable particles. To demonstrate this, explicit models of composite-composite particle scattering are constructed. Space-time conservation laws are not imposed separately on the system, but follow upon requiring the constituents to ''pair up'' into free composites at s = +infinity,-infinity. One model is characterized by the appearance of an ''external'' zero-mass composite particle which participates in the scattering process without affecting the space-time conservation laws of the two-composite system. Initial conditions on the two incoming composite particles and the zero-mass participant determine the scattering angle and the final states of the two outgoing composite particles. Although the formalism is classical, the model displays some features usually associated with quantum field theory, such as particle scattering by means of constituent exchange, creation and annihilation of particles, and restriction of values of angular momentum

Influence of the Crude Oil Characterization on Mmp Calculation Influence de la caractérisation d'un pétrole brut sur le calcul de la pression minimale de miscibilité

Directory of Open Access Journals (Sweden)

Neau E.

2006-11-01

Full Text Available This paper focuses on the influence of the crude oil characterization on minimum miscibility pressure (MMP calculation. It is shown what kind of compounds may be lumped together in order to calculate the MMP with a good accuracy. In a first step, a selected crude oil is modeled with 37 pure compounds using the characterization procedure developed by Avaullée et al. (1997a in which two parameters of the distillation residue are fitted on the experimental bubble points. In this context, all the experimental data (PVT, swelling test, slim tube test are calculated with a very good accuracy. In a second step, the heavy intermediate, the middle intermediate and the light compounds are successively lumped. The influence of such lumping procedure on the calculated MMP is discussed. Dans cet article, nous étudions l'influence de la modélisation des coupes d'un pétrole brut sur la valeur calculée de la pression minimale de miscibilité (MMP. En particulier, il est expliqué quels types de constituants peuvent être regroupés sous forme d'un pseudo-constituant sans pour autant dégrader la valeur de la MMP. La procédure suivie dans cet article est simple : à partir d'un pétrole brut donné, nous utilisons dans un premier temps une représentation par 37 composants, exploitant l'information analytique standard disponible sur ce fluide. La modélisation des fractions lourdes utilisée est celle développée par Avaullée et al. (1997a , dans laquelle nous avons ajusté deux paramètres du résidu de distillation C(20+ sur les pressions de saturation expérimentales. Sur le fluide étudié, nous mettons en évidence le bon niveau de restitution des grandeurs volumétriques, des données expérimentales de gonflement ainsi que de la MMP mesurée lors d'une expérience de déplacement en tube mince. Dans un deuxième temps, les composés intermédiaires lourds, les intermédiaires moyens et les composants légers font successivement l'objet de

User's manual for the Graphical Constituent Loading Analysis System (GCLAS)

Science.gov (United States)

Koltun, G.F.; Eberle, Michael; Gray, J.R.; Glysson, G.D.

2006-01-01

This manual describes the Graphical Constituent Loading Analysis System (GCLAS), an interactive cross-platform program for computing the mass (load) and average concentration of a constituent that is transported in stream water over a period of time. GCLAS computes loads as a function of an equal-interval streamflow time series and an equal- or unequal-interval time series of constituent concentrations. The constituent-concentration time series may be composed of measured concentrations or a combination of measured and estimated concentrations. GCLAS is not intended for use in situations where concentration data (or an appropriate surrogate) are collected infrequently or where an appreciable amount of the concentration values are censored. It is assumed that the constituent-concentration time series used by GCLAS adequately represents the true time-varying concentration. Commonly, measured constituent concentrations are collected at a frequency that is less than ideal (from a load-computation standpoint), so estimated concentrations must be inserted in the time series to better approximate the expected chemograph. GCLAS provides tools to facilitate estimation and entry of instantaneous concentrations for that purpose. Water-quality samples collected for load computation frequently are collected in a single vertical or at single point in a stream cross section. Several factors, some of which may vary as a function of time and (or) streamflow, can affect whether the sample concentrations are representative of the mean concentration in the cross section. GCLAS provides tools to aid the analyst in assessing whether concentrations in samples collected in a single vertical or at single point in a stream cross section exhibit systematic bias with respect to the mean concentrations. In cases where bias is evident, the analyst can construct coefficient relations in GCLAS to reduce or eliminate the observed bias. GCLAS can export load and concentration data in formats

Application of RAD-BCG calculator to Hanford's 300 area shoreline characterization dataset

Energy Technology Data Exchange (ETDEWEB)

Antonio, Ernest J.; Poston, Ted M.; Tiller, Brett L.; Patton, Gene W.

2003-07-01

Abstract. In 2001, a multi-agency study was conducted to characterize potential environmental effects from radiological and chemical contaminants on the near-shore environment of the Columbia River at the 300 Area of the U.S. Department of Energy’s Hanford Site. Historically, the 300 Area was the location of nuclear fuel fabrication and was the main location for research and development activities from the 1940s until the late 1980s. During past waste handling practices uranium, copper, and other heavy metals were routed to liquid waste streams and ponds near the Columbia River shoreline. The Washington State Department of Health and the Pacific Northwest National Laboratory’s Surface Environmental Surveillance Project sampled various environmental components including river water, riverbank spring water, sediment, fishes, crustaceans, bivalve mollusks, aquatic insects, riparian vegetation, small mammals, and terrestrial invertebrates for analyses of radiological and chemical constituents. The radiological analysis results for water and sediment were used as initial input into the RAD-BCG Calculator. The RAD-BCG Calculator, a computer program that uses an Excel® spreadsheet and Visual Basic® software, showed that maximum radionuclide concentrations measured in water and sediment were lower than the initial screening criteria for concentrations to produce dose rates at existing or proposed limits. Radionuclide concentrations measured in biota samples were used to calculate site-specific bioaccumulation coefficients (Biv) to test the utility of the RAD-BCG-Calculator’s site-specific screening phase. To further evaluate site-specific effects, the default Relative Biological Effect (RBE) for internal alpha particle emissions was reduced by half and the program’s kinetic/allometric calculation approach was initiated. The subsequent calculations showed the initial RAD-BCG Calculator results to be conservative, which is appropriate for screening purposes.

[Chemical constituents from rhizomes of Illicium henryi].

Science.gov (United States)

Liu, Jifeng; Zhang, Xuemei; Shi, Yao; Jiang, Zhiyong; Ma, Yunbao; Chen, Jijun

2010-09-01

To study the chemical constituents of Illicium henryi. Column chromatographic techniques using silica gel, Sephadex LH-20, Rp-8 and Rp-18 as packing materials were applied to isolate constituents. The structures of isolates were determined on the basis of spectroscopic data analyses. Twelve compounds were isolated from the rhizomes of I. henryi, which were characterized as balanophonin (1), aviculin (2), rubriflosides A (3), 1,2-bis(4-hydroxy-3-methoxyphenyl)-1,3-propanediol (4), jasopyran (5), kaempferol (6), quercetin (7), (2R, 3R)-3, 5, 7, 3', 5'- pentahydroxyflavan (8), 3, 4, 5-trimethoxyphenyl-1-O-beta-D-glucopyranoside (9), 3, 4-dimethoxyphenyl-1-O-beta-D-glucopyranoside (10), coniferyl aldehyde (11), sinapaldehyde (12), respectively. All the isolates were obtained for the first time from this plant.

The integration of the Constituent Congress in 1917

Directory of Open Access Journals (Sweden)

Juan Bernardino Sánchez Aguilar

2017-01-01

Full Text Available This paper offers a new perspective around the perception of political legitimacy held by the representatives to one of the most emblematic assemblies in Mexico. Reviewing the credentials of the Querétaro Constituent Congress allows us to observe the first internal disputes within constitutionalism, since plenty has been said about the enactment of the Political Constitution of the Mexican United States, whereas the legislative sessions that gave rise to it are not studied enough.  By presenting the chiaroscuros of the constituent parliamentary work, particularly during the first days of the electoral college, this article aims to complement the existing enormous historiographic production on this Congress.

Structure and reactivity of oxalate surface complexes on lepidocrocite derived from infrared spectroscopy, DFT-calculations, adsorption, dissolution and photochemical experiments

Science.gov (United States)

Borowski, Susan C.; Biswakarma, Jagannath; Kang, Kyounglim; Schenkeveld, Walter D. C.; Hering, Janet G.; Kubicki, James D.; Kraemer, Stephan M.; Hug, Stephan J.

2018-04-01

Oxalate, together with other ligands, plays an important role in the dissolution of iron(hdyr)oxides and the bio-availability of iron. The formation and properties of oxalate surface complexes on lepidocrocite were studied with a combination of infrared spectroscopy (IR), density functional theory (DFT) calculations, dissolution, and photochemical experiments. IR spectra measured as a function of time, concentration, and pH (50-200 μM oxalate, pH 3-7) showed that several surface complexes are formed at different rates and in different proportions. Measured spectra could be separated into three contributions described by Gaussian line shapes, with frequencies that agreed well with the theoretical frequencies of three different surface complexes: an outer-sphere complex (OS), an inner-sphere monodentate mononuclear complex (MM), and a bidentate mononuclear complex (BM) involving one O atom from each carboxylate group. At pH 6, OS was formed at the highest rate. The contribution of BM increased with decreasing pH. In dissolution experiments, lepidocrocite was dissolved at rates proportional to the surface concentration of BM, rather than to the total adsorbed concentration. Under UV-light (365 nm), BM was photolyzed at a higher rate than MM and OS. Although the comparison of measured spectra with calculated frequencies cannot exclude additional possible structures, the combined results allowed the assignment of three main structures with different reactivities consistent with experiments. The results illustrate the importance of the surface speciation of adsorbed ligands in dissolution and photochemical reactions.

Chemical investigation of the volatile constituents of Cleome viscosa from Nigeria

Directory of Open Access Journals (Sweden)

Gabriel Olatunji

2005-06-01

Full Text Available The major volatile constituents of the oils from the integral parts of Cleome viscosa L. from Nigeria have been identified by GC, GC/MS and 1H NMR. The main constituents of the non-polar fraction of the oils were monoterpene hydrocarbons (21% in stem/leaves, 15% in seed/fruits, 12% in roots and some oxygenated derivatives (3% in leaves/stem; 1% in seeds/fruits and 1.5% in roots. The monoterpenes occurred frequently in the oils. Fatty acid esters especially ethyl palmitate which constituted a major constituent in the oil from the seeds/fruits was not detected in the oils from the roots.

"My First Thought was Croutons": Perceptions of Cigarettes and Cigarette Smoke Constituents Among Adult Smokers and Nonsmokers.

Science.gov (United States)

Moracco, Kathryn E; Morgan, Jennifer C; Mendel, Jennifer; Teal, Randall; Noar, Seth M; Ribisl, Kurt M; Hall, Marissa G; Brewer, Noel T

2016-07-01

Understanding what people think about harmful and potentially harmful constituents in cigarettes and cigarette smoke has new urgency given legislation requiring US Food and Drug Administration (FDA) to disclose constituent information. Our study sought to obtain qualitative information on what people think about these constituents and the language they use to talk about them. We conducted six focus groups in 2014 with 40 adults in North Carolina. Open-ended questions focused on cigarette and cigarette smoke constituents in general and on the 18 constituents on the FDA's abbreviated list. We coded the transcripts for emergent themes, and all four coders discussed themes until we reached consensus. Participants knew that cigarette smoke contains chemicals but did not know how many chemicals nor what those chemicals are, beyond tar and nicotine. Dangers of constituents mentioned included "chemicals," physical disease, and addiction. Participants incorrectly believed harmful constituents came primarily from tobacco companies' additives. For unfamiliar constituents, people tried to make associations based on similar-sounding words. Recognizable constituents that participants associated with health harms most discouraged them from wanting to smoke. Most participants wanted to know health harms associated with constituents and what else the chemicals were in. Participants showed enthusiasm for learning more information about constituents, and also showed substantial misunderstandings about the source of harmful constituents. Our findings contribute to the limited body of research on adults' knowledge and perceptions of cigarette smoke constituents and can aid the FDA as it plans to disclose constituent information to the public. Our study provides information about adults' understanding of cigarette smoke constituents and what adults would like to know about these constituents. This information can help communication campaigns describe cigarette smoke constituents in a

QMX: A versatile environment for hybrid calculations applied to the grafting of Al 2 Cl 3 Me 3 on a silica surface

KAUST Repository

Kerber, Torsten

2013-01-23

We present a new software to easily perform QM:MM and QM:QM\\' calculations called QMX. It follows the subtraction scheme and it is implemented in the Atomic Simulation Environment (ASE). Special attention is paid to couple molecular calculations with periodic boundaries approaches. QMX inherits the flexibility and versatility of the ASE package: any combination of methods namely force field, semiempirical, first principle, and ab initio, can be used as hybrid potential energy surface (PES). Its ease of use is demonstrated by considering the adsorption of Al2Cl3Me3 on silica surface and by combining different levels of theory (from standard DFT to MP2 calculations) for the so-called High Level cluster with standard PW91 density functional theory calculations for the Low Level environment. It is shown that the High Level cluster must contain the silanol group close to the aluminum atoms. The bridging adsorption is favored by 58 kJ mol-1 at the MP2:PW91 level with respect to the terminal position. Using large clusters at the MP2:PW91 level, it is shown that PW91 calculations are sufficient for structure optimization but that embedded methods are required for accurate energy profiles. © 2013 Wiley Periodicals, Inc.

Methode des Rayons avec Calcul d’Intensite Appliquee a la Propagation Anormale (Method of Ray Intensity Calculation as Applied to Anomalous Propagation),

Science.gov (United States)

1986-06-01

plus rapproch~es. Cette question, qui constitue en elle-mgme un domaine de recherche, d~ borde du cadre du present rapport. * Il est possible d’gtendre...par la commande JCL "PROPEX:T.’ qui produit le module ex~cutable "PROPAG:EX". TABLEAU I Bloc principal PROPAK *NOM DES ROUTINES FONCTION PROPAG...alise la r &mission des rayons r~fl~chis e77 SANS CLASSIFICATION 22 TABLEAU II Bloc utilitaire UTILPAK NOM DES ROUTINES FONCTION H - Calcule r la

Recoilless fractions calculated with the nearest-neighbour interaction model by Kagan and Maslow

Science.gov (United States)

Kemerink, G. J.; Pleiter, F.

1986-08-01

The recoilless fraction is calculated for a number of Mössbauer atoms that are natural constituents of HfC, TaC, NdSb, FeO, NiO, EuO, EuS, EuSe, EuTe, SnTe, PbTe and CsF. The calculations are based on a model developed by Kagan and Maslow for binary compounds with rocksalt structure. With the exception of SnTe and, to a lesser extent, PbTe, the results are in reasonable agreement with the available experimental data and values derived from other models.

Synthesis and Surface-Specific Analysis of Molecular Constituents Relevant to Biogenic Secondary Organic Aerosol Material

Science.gov (United States)

Be, A. G.; Upshur, M. A.; Chase, H. M.; Geiger, F.; Thomson, R. J.

2017-12-01

Secondary organic aerosol (SOA) particles formed from the oxidation of biogenic volatile organic compounds (BVOCs) remain a principal, yet elusive, class of airborne particulate matter that impacts the Earth's radiation budget. Given the characteristic molecular complexity comprising biogenic SOA particles, chemical information selective to the gas-aerosol interface may be valuable in the investigation of such systems, as surface considerations likely dictate the phenomena driving particle evolution mechanisms and climate effects. In particular, cloud activation processes may be parameterized using the surface tension depression that coincides with partitioning of surface-active organic species to the gas-droplet interface. However, the extent to which surface chemical processes, such as cloud droplet condensation, are influenced by the chemical structure and reactivity of individual surface-active molecules in SOA particles is largely unknown. We seek to study terpene-derived organic species relevant to the surfaces of biogenic SOA particles via synthesis of putative oxidation products followed by analysis using surface-selective physicochemical measurements. Using dynamic surface tension measurements, considerable differences are observed in the surface tension depression of aqueous pendant droplets that contain synthetically prepared ozonolysis products derived from abundant terpene precursors. Furthermore, sum frequency generation spectroscopy is utilized for comparison of the surface vibrational spectral responses of synthesized reference compounds with those observed for laboratory aerosol toward probing the surface composition of SOA material. Such ongoing findings highlight the underlying importance of molecular structure and reactivity when considering the surface chemistry of biogenic terpene-derived atmospheric aerosols.

The fragrance mix and its constituents

DEFF Research Database (Denmark)

Johansen, J D; Menné, T

1995-01-01

Results from 14 years of patch testing with the fragrance mix and its constituents are reviewed. From 1979-1992, 8215 consecutive patients were patch tested with the fragrance mix and 449 (5.5%) had a positive reaction. An increase in the frequency of reactions to fragrance mix was seen from the ...

FOCUS AND CONSTITUENT QUESTION FORMATION IN DAGBANI

African Journals Online (AJOL)

Issah

Key words: SpecFoc, focus marker, clause initial, constituent interrogatives, information ... 1Throughout this work, I use the phrase interrogative words in a general way to refer to the ...... Wh-Questions and extraction asymmetries in Malagasy.

Evaporation rates and surface profiles on heterogeneous surfaces with mass transfer and surface reaction

Energy Technology Data Exchange (ETDEWEB)

Flytzani-Stephanopoulos, M; Schmidt, L D

1979-01-01

Simple models incorporating surface reaction and diffusion of volatile products through a boundary layer are developed to calculate effective rates of evaporation and local surface profiles on surfaces having active and inactive regions. The coupling between surface heterogeneities with respect to a particular reaction and external mass transfer may provide a mechanism for the surface rearrangement and metal loss encountered in several catalytic systems of practical interest. Calculated transport rates for the volatilization of platinum in oxidizing environments and the rearrangement of this metal during the ammonia oxidation reaction agree well with published experimental data.

Monte carlo calculation of the neutron effective dose rate at the outer surface of the biological shield of HTR-10 reactor

International Nuclear Information System (INIS)

Remetti, Romolo; Andreoli, Giulio; Keshishian, Silvina

2012-01-01

Highlights: ► We deal with HTR-10, that is a helium-cooled graphite-moderated pebble bed reactor. ► We carried out Monte Carlo simulation of the core by MCNP5. ► Extensive use of MCNP5 variance reduction methods has been done. ► We calculated the trend of neutron flux within the biological shield. ► We calculated neutron effective dose at the outer surface of biological shield. - Abstract: Research on experimental reactors, such as HTR-10, provide useful data about potentialities of very high temperature gas-cooled reactors (VHTR). The latter is today rated as one of the six nuclear reactor types involved in the Generation-IV International Forum (GIF) Initiative. In this study, the MCNP5 code has been employed to evaluate the neutron radiation trend vs. the biological shield's thickness and to calculate the neutron effective dose rate at the outer surface. The reactor's geometry has been completely modeled by means of lattices and universes provided by MCNP, even though some approximations were required. Monte Carlo calculations have been performed by means of a simple PC and, as a consequence, in order to obtain acceptable run times, it was made an extensive recourse to variance reduction methods.

Updates to Constituent Subtraction in Heavy Ions at CMS

CERN Document Server

CMS Collaboration

2018-01-01

The latest upgrades and performance of constituent subtraction in 5.02 TeV PbPb collisions is presented. The constituent subtraction is extended through the full tracker acceptance, increasing the rapidity reach of correctly subtracted jets. A modulation in azimuthal angle is added to the subtraction, accounting for flow on an event-by-event basis and improving jet energy resolution. Closure of jet energy scale after corrections and jet energy resolution is shown for R=0.4 and R=0.8 jets, the latter for the first time in CMS Heavy-Ions.

First-principles calculations of vacancy formation in In-free photovoltaic semiconductor Cu2ZnSnSe4

International Nuclear Information System (INIS)

Maeda, Tsuyoshi; Nakamura, Satoshi; Wada, Takahiro

2011-01-01

To quantitatively evaluate the formation energies of Cu, Zn, Sn, and Se vacancies in kesterite-type Cu 2 ZnSnSe 4 (CZTSe), first-principles pseudopotential calculations using plane-wave basis functions were performed. The formation energies of neutral Cu, Zn, Sn and Se vacancies were calculated as a function of the atomic chemical potentials of constituent elements. The obtained results were as follows: (1) the formation energy of Cu vacancy was generally smaller than those of the other Zn, Sn and Se vacancies, (2) under the Cu-poor and Zn-rich condition, the formation energy of Cu vacancy was particularly low, (3) the formation energy of Zn vacancy greatly depended on the chemical potentials of the constituent elements and under the Zn-poor and Se-rich condition, the formation energy of Zn vacancy was smaller than that of Cu vacancy, and (4) the formation energy of Sn vacancy did not greatly depend on the chemical potentials of the constituent elements and was much larger than those of Cu, Zn, and Se vacancies. These results indicate that Cu vacancy is easily formed under Cu-poor and Zn-rich conditions, but Zn vacancy is easily formed under the Zn-poor and Se-rich conditions.

Distribution of radioactive constituents in river waters

International Nuclear Information System (INIS)

Herranz, M.; Elejalde, C.; Legarda, F.; Romero, F.

1994-01-01

For a research project on the distribution and evaluation of natural and artificial radioactive constituents in ecological segments of Biscay (northeast spain), the amounts of nuclides present in the main river waters were measured. Radioactive procedures include i) total alpha and beta indexes with a gas flow detector, dry residues near to 2 and 10 mg/ cm sup 2, respectively and counting periods of 1000 mn, ii) gamma emitters with a low level gamma spectrometer (Ge-HP detector + 8000 channels analyser) using the dry residue from 8 litres and a counting period of 4 days and iii) statistical treatment of data at 95% confidence.In this paper, ten water samples from the nervion river basin are included. Physical and chemical parameters of samples were also determined by standard procedures, because there is a sharp change in the composition of this river in the first part of the course. Radioactive constituents were identified as follows: a sample has a detectable alpha index, all samples contains beta emitters with a high variability, natural nuclides from uranium and thorium families were detected in some cases. A parallel behaviour is found between samples where K-40 and Cs-137 were found. The paper tries at last to find relations among chemical and radioactive constituents by the application of multivariate statistical methods, specially for the case of Cs-137, the only artificial nuclide identified in this work. 1 tab., 2 figs., 5 refs. (author)

Constituent quarks in nuclear matter and the Nolen-Schiffer anomaly

International Nuclear Information System (INIS)

Lutz, M.; Lee, H.K.; Weise, W.

1991-01-01

We investigate the density dependence of the neutron-proton mass difference using the Nambu and Jona-Lasinio model in combination with the Isgur-Karl constituent quark model. The decrease of the constituent quark masses with increasing density reduces the n-p mass difference in the proper way to help resolving the Nolen-Schiffer anomaly. We point out however, that in the presence of vector interactions, this effect is less pronounced than previously suggested. (orig.)

Quark solitons as constituents of hadrons

International Nuclear Information System (INIS)

Ellis, J.; Frishman, Y.; Hanany, A.; Karlinev, M.

1992-01-01

We exhibit static solutions of multi-flavour QCD in two dimensions that have the quantum numbers of baryons and mesons, constructed out of quark and anti-quark solitons. In isolation the latter solitons have infinite energy, corresponding to the presence of a string carrying the non-singlet colour flux off to spatial infinity. When N c solitons of this type are combined, a static, finite-energy, colour singlet solution is formed, corresponding to a baryon. Similarly, static meson solutions are formed out of a soliton and an anti-soliton of different flavours. The stability of the mesons against annihilation is ensured by flavour conservation. The static solutions exist only when the fundamental fields of the bosonized lagrangian belong to U(N c xN f ) rather than to SU(N c )xU(N f ). Discussion of flavour-symmetry breaking requires a careful treatment of the normal-ordering ambiguity. Our results can be viewed as a derivation of the constituent quark model in QCD 2 , allowing a detailed study of constituent mass generation and of the heavy-quark symmetry. (orig.)

Microstructures and constituents of super-high strength aluminum alloy ingots made through LFEC process

Directory of Open Access Journals (Sweden)

WANG Shuang

2007-11-01

Full Text Available Ingots of a new super-high strength Al-Zn-Mg-Cu-Zr alloy were produced respectively by low frequency electromagnetic casting (LFEC and by conventional direct chill (DC casting process. Microstructure and constituents of the ingots were studied. The results indicated that the LFEC process significantly refines microstructure and constituents of the alloy, and to some extent, decreases the area (or volume fraction of constituents and eutectic structure precipitated at grain boundaries. But, no difference in the type of constituents was observed between LFEC and DC ingots. The results also showed LFEC process can improve the as-cast mechanical properties.

Pyrrolizidine Alkaloids: Testing for Toxic Constituents of Comfrey.

Science.gov (United States)

Vollmer, John J.; And Others

1987-01-01

Discusses the possibilities of toxins present in medicinal herbs. Describes an experiment in which toxic constituents can be selectively detected by thin-layer chromatography and NMR spectroscopy. (TW)

NMR characterization of hydrocarbon adsorption on calcite surfaces: A first principles study

Energy Technology Data Exchange (ETDEWEB)

Bevilaqua, Rochele C. A.; Miranda, Caetano R. [Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, UFABC, Santo André, SP (Brazil); Rigo, Vagner A. [Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, UFABC, Santo André, SP (Brazil); Universidade Tecnológica Federal do Paraná, UTFPR, Cornélio Procópio, PR (Brazil); Veríssimo-Alves, Marcos [Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, UFABC, Santo André, SP (Brazil); Departamento de Física, ICEx, Universidade Federal Fluminense, UFF, Volta Redonda, RJ (Brazil)

2014-11-28

The electronic and coordination environment of minerals surfaces, as calcite, are very difficult to characterize experimentally. This is mainly due to the fact that there are relatively few spectroscopic techniques able to detect Ca{sup 2+}. Since calcite is a major constituent of sedimentary rocks in oil reservoir, a more detailed characterization of the interaction between hydrocarbon molecules and mineral surfaces is highly desirable. Here we perform a first principles study on the adsorption of hydrocarbon molecules on calcite surface (CaCO{sub 3} (101{sup ¯}4)). The simulations were based on Density Functional Theory with Solid State Nuclear Magnetic Resonance (SS-NMR) calculations. The Gauge-Including Projector Augmented Wave method was used to compute mainly SS-NMR parameters for {sup 43}Ca, {sup 13}C, and {sup 17}O in calcite surface. It was possible to assign the peaks in the theoretical NMR spectra for all structures studied. Besides showing different chemical shifts for atoms located on different environments (bulk and surface) for calcite, the results also display changes on the chemical shift, mainly for Ca sites, when the hydrocarbon molecules are present. Even though the interaction of the benzene molecule with the calcite surface is weak, there is a clearly distinguishable displacement of the signal of the Ca sites over which the hydrocarbon molecule is located. A similar effect is also observed for hexane adsorption. Through NMR spectroscopy, we show that aromatic and alkane hydrocarbon molecules adsorbed on carbonate surfaces can be differentiated.

Technetium getters in the near surface environment

International Nuclear Information System (INIS)

Krumhansl, James L.; Zhang, Pengchu; Westrich, Henry R.; Bryan, Charles R.; Molecke, Martin A.

2000-01-01

Conventional performance assessments assume that radioactive 99 Tc travels as a non-sorbing component with an effective K d (distribution coefficient) of 0. This is because soil mineral surfaces commonly develop net negative surface charges and pertechnetate (TcO 4 ), with large ionic size and low electrical density, is not sorbed onto them. However, a variety of materials have been identified that retain Tc and may eventually lead to promising Tc getters. In assessing Tc getter performance it is important to evaluate the environment in which the getter is to function. In many contaminant plumes Tc will only leach slowly from the source of the contamination and significant dilution is likely. Thus, sub-ppb Tc concentrations are expected and normal groundwater constituents will dominate the aquifer chemistry. In this setting a variety of constituents were found to retard TcO 4 : imogolite, boehmite, hydrotalcite, goethite, copper sulfide and oxide and coal. Near leaking tanks of high level nuclear waste, Tc may be present in mg/L level concentrations and groundwater chemistry will be dominated by constituents from the waste. Both bone char, and to a lesser degree, freshly precipitated Al hydroxides may be effective Tc scavengers in this environment. Thus, the search for Tc getters is far from hopeless, although much remains to be learned about the mechanisms by which these materials retain Tc

Constituent order and semantic parallelism in online comprehension: eye-tracking evidence from German.

Science.gov (United States)

Knoeferle, Pia; Crocker, Matthew W

2009-12-01

Reading times for the second conjunct of and-coordinated clauses are faster when the second conjunct parallels the first conjunct in its syntactic or semantic (animacy) structure than when its structure differs (Frazier, Munn, & Clifton, 2000; Frazier, Taft, Roeper, & Clifton, 1984). What remains unclear, however, is the time course of parallelism effects, their scope, and the kinds of linguistic information to which they are sensitive. Findings from the first two eye-tracking experiments revealed incremental constituent order parallelism across the board-both during structural disambiguation (Experiment 1) and in sentences with unambiguously case-marked constituent order (Experiment 2), as well as for both marked and unmarked constituent orders (Experiments 1 and 2). Findings from Experiment 3 revealed effects of both constituent order and subtle semantic (noun phrase similarity) parallelism. Together our findings provide evidence for an across-the-board account of parallelism for processing and-coordinated clauses, in which both constituent order and semantic aspects of representations contribute towards incremental parallelism effects. We discuss our findings in the context of existing findings on parallelism and priming, as well as mechanisms of sentence processing.

SU/sub 3/ and color properties of the psi constituents

Energy Technology Data Exchange (ETDEWEB)

Wolfenstein, L [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA)

1976-06-19

It is suggested that the psi constituents form a (3,1) representation of SU/sub 3/xSU/sub 3/c rather than (1,3) as in the charm scheme. Within the framework of confined color this allows the psi constituents to be produced above some threshold and decay weakly, as suggested in recent models. Some general consequences of this classification are discussed and a specific scheme which may help to resolve some problems in psi spectroscopy is presented.

Calculational examination of the Baneberry event

International Nuclear Information System (INIS)

Terhune, R.W.; Glenn, H.D.; Burton, D.E.; McKague, H.L.; Rambo, J.T.

1977-01-01

On December 18, 1970, Baneberry, a 10-kt nuclear device, was detonated at a depth of 278 m in hole U8d at the Nevada Test Site. A shock-induced fissure near ground zero opened and vented radioactive gases and debris into the atmosphere. This report presents the calculational results describing the sequence of dynamic phenomena that produced the vent. The calculations predict the long positive velocity pulse and the surface motion that were observed experimentally. The surface fissure through which the material vented is the same radial distance from ground zero as the maximum horizontal displacement is calculated to be. The calculations predict a final cavity radius that is very close to the measured Baneberry cavity radius. Finally, the calculations indicate that an open fracture path runs from the cavity to the Baneberry Fault, up the fault to the spall region, and then vertically to the surface. This was the vent path predicted by calculations and is consistent with the vent path found from the radioactivity in postshot drill holes. Because of our extensions in computational capabilities, we believe this report advances the state of the art for numerical simulation of the containment problems associated with underground nuclear tests

Calculation of rectal dose surface histograms in the presence of time varying deformations

International Nuclear Information System (INIS)

Roeske, John C.; Spelbring, Danny R.; Vijayakumar, S.; Forman, Jeffrey D.; Chen, George T.Y.

1996-01-01

Purpose: Dose volume (DVH) and dose surface histograms (DSH) of the bladder and rectum are usually calculated from a single treatment planning scan. These DVHs and DSHs will eventually be correlated with complications to determine parameters for normal tissue complication probabilities (NTCP). However, from day to day, the size and shape of the rectum and bladder may vary. The purpose of this study is to compare a more accurate estimate of the time integrated DVHs and DSHs of the rectum (in the presence of daily variations in rectal shape) to initial DVHs/DSHs. Methods: 10 patients were scanned once per week during the course of fractionated radiotherapy, typically accumulating a total of six scans. The rectum and bladder were contoured on each of the studies. The model used to assess effects of rectal contour deformation is as follows: the contour on a given axial slice (see figure) is boxed within a rectangle. A line drawn parallel to the AP axis through the rectangle equally partitions the box. Starting at the intersection of the vertical line and the rectal contour, points on the contour are marked off representing the same rectal dose point, even in the presence of distortion. Corresponding numbered points are used to sample the dose matrix and create a composite DSH. The model assumes uniform stretching of the rectal contour for any given axial cut, and no twist of the structure or vertical displacement. A similar model is developed for the bladder with spherical symmetry. Results: Normalized DSHs (nDSH) for each CT scan were calculated as well as the time averaged nDSH over all scans. These were compared with the nDSH from the initial planning scan. Individual nDSHs differed by 8% surface area irradiated at the 80% dose level, to as much as 20% surface area in the 70-100% dose range. DSH variations are due to position and shape changes in the rectum during different CT scans. The spatial distribution of dose is highly variable, and depends on the field

Calculation of plastic deformation of a conical shell with the transformation of inner surface into outer one

Directory of Open Access Journals (Sweden)

A. I. Uvarov

2014-01-01

Full Text Available An analytical model of plastic deformation of a conical shell with the transformation of internal surface into outer one was developed with a use of the kinematic method. The shell material was assumed to be perfectly plastic. The theory of thin shells and the kinematic theorem of limit equilibrium were utilized in this work. Both geometric and physical nonlinearities were taken into account. Dependences for calculating radius of curvature of the intensive deformation zones, value of chain ring deformation and values of the deforming force as a function of axial displacement were determined. Analysis showed the possibility of using a conical shell to absorb energy with high efficiency. Obtained results could be used for calculation and selection of optimal parameters of the energy-absorbing elements in shock absorbers.

MULTIMODE quantum calculations of vibrational energies and IR spectrum of the NO{sup +}(H{sub 2}O) cluster using accurate potential energy and dipole moment surfaces

Energy Technology Data Exchange (ETDEWEB)

Homayoon, Zahra, E-mail: zhomayo@emory.edu [Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322 (United States)

2014-09-28

A new, full (nine)-dimensional potential energy surface and dipole moment surface to describe the NO{sup +}(H{sub 2}O) cluster is reported. The PES is based on fitting of roughly 32 000 CCSD(T)-F12/aug-cc-pVTZ electronic energies. The surface is a linear least-squares fit using a permutationally invariant basis with Morse-type variables. The PES is used in a Diffusion Monte Carlo study of the zero-point energy and wavefunction of the NO{sup +}(H{sub 2}O) and NO{sup +}(D{sub 2}O) complexes. Using the calculated ZPE the dissociation energies of the clusters are reported. Vibrational configuration interaction calculations of NO{sup +}(H{sub 2}O) and NO{sup +}(D{sub 2}O) using the MULTIMODE program are performed. The fundamental, a number of overtone, and combination states of the clusters are reported. The IR spectrum of the NO{sup +}(H{sub 2}O) cluster is calculated using 4, 5, 7, and 8 modes VSCF/CI calculations. The anharmonic, coupled vibrational calculations, and IR spectrum show very good agreement with experiment. Mode coupling of the water “antisymmetric” stretching mode with the low-frequency intermolecular modes results in intensity borrowing.

Light-Absorbing Brown Carbon Aerosol Constituents from Combustion of Indonesian Peat and Biomass.

Science.gov (United States)

Budisulistiorini, Sri Hapsari; Riva, Matthieu; Williams, Michael; Chen, Jing; Itoh, Masayuki; Surratt, Jason D; Kuwata, Mikinori

2017-04-18

Light-absorbing brown carbon (BrC) constituents of organic aerosol (OA) have been shown to significantly absorb ultraviolet (UV) and visible light and thus impact radiative forcing. However, molecular identification of the BrC constituents is still limited. In this study, we characterize BrC constituents at the molecular level in (i) aerosols emitted by combustion of peat, fern/leaf, and charcoal from Indonesia and (ii) ambient aerosols collected in Singapore during the 2015 haze episode. Aerosols were analyzed using ultra performance liquid chromatography instrument interfaced to a diode array detector and electrospray ionization high-resolution quadrupole time-of-flight mass spectrometer operated in the negative ion mode. In the laboratory-generated aerosols, we identified 41 compounds that can potentially absorb near-UV and visible wavelengths, such as oxygenated-conjugated compounds, nitroaromatics, and S-containing compounds. The sum of BrC constituents in peat, fern/leaf, and charcoal burning aerosols are 16%, 35%, and 28% of the OA mass, respectively, giving an average contribution of 24%. On average, the BrC constituents account for 0.4% of the ambient OA mass; however, large uncertainties in mass closure remain because of the lack of authentic standards. This study highlights the potential of light-absorbing BrC OA constituents from peat, fern/leaf, and charcoal burning and their importance in the atmosphere.

Effect of coffee reduction on constituent concentration in an energy-efficient process of ultrasonic extraction

Directory of Open Access Journals (Sweden)

Wang Cheng-Chi

2015-01-01

Full Text Available Coffee is one of the popular beverage; its constituents include caffeine, oxidation resistant aromatic constituents, protein, tannin, and fat. It is indicated in literatures that a proper amount of coffee stimulates the brain and enhances memory, but excessive coffee causes negative results, such as coronary artery disease, high blood pressure, heart disease and kidney disease. This study used high-performance ultrasonic process to discuss the effect of pulverized coffee reduction on the constituent concentration. It further compared the constituent concentrations obtained in different extraction periods. The experimental results show that the coffee aroma constituents can be extracted effectively by ultrasonic process without any organic solvent, and the constituent concentration does not decrease with the addition of pulverized coffee. Therefore, the consumption of pulverized coffee can be reduced greatly by using the proposed. The time of extraction process can be shortened, so as to save energy. The most important point is to reduce the enterprises manufacturing cost and to increase the profit.

Surface passivation for tight-binding calculations of covalent solids

International Nuclear Information System (INIS)

Bernstein, N

2007-01-01

Simulation of a cluster representing a finite portion of a larger covalently bonded system requires the passivation of the cluster surface. We compute the effects of an explicit hybrid orbital passivation (EHOP) on the atomic structure in a model bulk, three-dimensional, narrow gap semiconductor, which is very different from the wide gap, quasi-one-dimensional organic molecules where most passivation schemes have been studied in detail. The EHOP approach is directly applicable to minimal atomic orbital basis methods such as tight-binding. Each broken bond is passivated by a hybrid created from an explicitly expressed linear combination of basis orbitals, chosen to represent the contribution of the missing neighbour, e.g. a sp 3 hybrid for a single bond. The method is tested by computing the forces on atoms near a point defect as a function of cluster geometry. We show that, compared to alternatives such as pseudo-hydrogen passivation, the force on an atom converges to the correct bulk limit more quickly as a function of cluster radius, and that the force is more stable with respect to perturbations in the position of the cluster centre. The EHOP method also obviates the need for parameterizing the interactions between the system atoms and the passivating atoms. The method is useful for cluster calculations of non-periodic defects in large systems and for hybrid schemes that simulate large systems by treating finite regions with a quantum-mechanical model, coupled to an interatomic potential description of the rest of the system

Argon ion beam interaction on polyethylene terephthalate surface by ...

Indian Academy of Sciences (India)

discharge treatment and laser irradiation are used. ... vation: where the interaction of plasma with the polymer involves both gas and surface .... that of metals [17]. ... with atmospheric constituents such as oxygen, water vapour and CO2 reduce ...

Surface and groundwater management in the oil sands industry

International Nuclear Information System (INIS)

Dixon, D.G.; Barker, J.

2004-02-01

A study was conducted to examine the sublethal effects of oil sands constituents on gill and liver histopathology and fish reproduction. Field studies of food web dynamics were conducted using stable isotopes, including oil sands constituents degradation isotope studies. The objective was to determine changes in food web dynamics associated with reclamation methods and maturity using stable isotopes. The study related changes in toxicity to changes in ground and surface naphthenic acids concentration and composition. It also demonstrated the natural attenuation of toxic chemicals as they travel through groundwater to potential surface water receptors. A methodology was developed to assess the natural attenuation capacity for future situations involving process-affected groundwater of different chemistry with different critical potential contaminants such as sulphides, metals, and specific organics. The mobility and natural attenuation of process water chemicals migrating in groundwater was also assessed. tabs., figs

An investigation of entrance surface dose calculations for diagnostic radiology using Monte Carlo simulations and radiotherapy dosimetry formalisms

International Nuclear Information System (INIS)

Omrane, L Ben; Verhaegen, F; Chahed, N; Mtimet, S

2003-01-01

Our aim in this work was to investigate the methodology used in the determination of the entrance surface dose (ESD) in diagnostic radiology. In kV x-rays for low-energy photons (tube potential up to 160 kV, HVL: 1-8 mm Al), the ESD is based on the use of the ratio of mass-energy absorption coefficients and backscatter factors. A full simulation of the photon and electron transport in a kilovoltage x-ray unit, using the Monte Carlo code BEAM/EGS4, was performed to obtain an accurate beam phase space for use in dose calculation. The modelled phase space was experimentally validated for the beam qualities (measured HVL: 3.3 mm Al-2.2 mm Cu) and showed good agreement between calculated and measured HVLs, air kerma and relative dose distributions. We have computed the conversion factors from air kerma to water or soft tissue absorbed dose at the surface of a phantom for beam qualities (HVL: 3.3-8.35 mm Al). The same model was also used to calculate the ESD in water and in soft tissue for the low-energy photon range considered. The results show that the numerical differences between the air kerma and the water kerma based backscatter factors are insignificant. The same conclusion was reached for the (μ en /ρ) ratios, for soft tissue to air, evaluated using either the primary photon spectra or the spectra at the surface of a phantom. Furthermore, the good agreement obtained for the computation of the conversion factors with a full BEAM/EGS4 model confirms the previous studies which are based on different sources for the spectral distribution and different beam geometries (pencil beam or point source assumptions). On the other hand, the ESD in water or soft tissue is well described either with the B air or the B w formalism. Conversion factors from air kerma to ESD in these media are proposed in this work for several beam qualities in diagnostic radiology

[Studies on flavone constituents of Erigeron breviscapus (Vant.) Hand.-Mazz].

Science.gov (United States)

Zhang, W D; Chen, W S; Wang, Y H; Liu, W Y; Kong, D Y; Li, H T

2000-09-01

To study the chemical constituents of Erigeron breviscapus. The constituents were separated and purified by column chromatography with silica gel, and identified by IR, MS, NMR and physical data. Five compounds were isolated and identified as 3, 5, 6, 4'-tetrahydroxy-7-methoxy flavonoid(I); 5, 7, 4'-trihydroxy flavonoid(II); 3, 5, 6, 7, 4'-pentahydroxy flavonoid(III); scutellarein (IV) and 5, 7, 4'-trihydroxy flavanone(V). Compounds I, III and V were isolated from this plant for the first time.

Simultaneous Determination of Seven Constituents in Herbal ...

African Journals Online (AJOL)

Simultaneous Determination of Seven Constituents in Herbal Prescription Jaeumganghwa-Tang Using HPLC-PDA. CS Seo, JH Kim, HK Shin. Abstract. A simple and accurate high-performance liquid chromatographic method was applied to the quantitative analysis of seven components of the traditional herbal prescription ...

Patch testing with constituents of Compositae mixes

DEFF Research Database (Denmark)

Paulsen, Evy; Andersen, Klaus Ejner

2012-01-01

Background. The development of mixes containing Compositae plant extracts has improved the diagnosis of Compositae contact allergy, but none of them has fulfilled the criteria for an ideal European plant mix. Objective. To evaluate which constituents of two commercial Compositae mixes were most u...

The Effects of Filter Ventilation on Flavor Constituents in Cigarette Smoke

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Jing Y

2014-12-01

Full Text Available The deliveries of 20 added flavor constituents, total particulate matter (TPM, nicotine, ‘tar’ carbon monoxide and water in cigarette mainstream smoke were studied when filter ventilation was 0, 10%, 30%, 50% and 70%, respectively. The flavor substance test was done by addition of standard samples. The flavor constituents in cigarette smoke condensate were separated by simultaneous distillation-extraction (SDE and capillary gas chromatography (GC. The flavor constituents were identified and determined quantitatively by gas chromatography-mass spectrometry (GC-MS and GC. The flavors studied were methylpyrazine, furaldehyde, 5-methylfuraldehyde, benzaldehyde, 6-methyl-5-hepten-2-one, trimethylpyrazine, 2-acetylpyridine, phenylacetaldehyde, acetophenone, linalool, b-phenylethyl alcohol, isophorone, oxoisophorone, benzyl acetate, menthol, ethyl octanoate, b-damascenone, b-damascone, geranylacetone and b-ionone. The deliveries of TPM, nicotine, ‘tar’ carbon monoxide and water in mainstream smoke were determined according to International Standard methods. It was found that the flavor constituents and routine components in mainstream smoke decreased in different proportions as the filter ventilation increased. Carbon monoxide and ‘tar’ decreased more than nicotine. The flavor constituents with lower boiling points and lower molecular weights decreased more than those with higher boiling points and higher molecular weights. With the increase of filter ventilation, not only is the amount of smoke components reduced and the smoke taste weakened, but also the composition of smoke is modified and the quality of aroma changed slightly. These findings should be considered when developing low-‘tar’ cigarettes through the use of filter ventilation technology.

Modeling of the effect of freezer conditions on the principal constituent parameters of ice cream by using response surface methodology.

Science.gov (United States)

Inoue, K; Ochi, H; Taketsuka, M; Saito, H; Sakurai, K; Ichihashi, N; Iwatsuki, K; Kokubo, S

2008-05-01

A systematic analysis was carried out by using response surface methodology to create a quantitative model of the synergistic effects of conditions in a continuous freezer [mix flow rate (L/h), overrun (%), cylinder pressure (kPa), drawing temperature ( degrees C), and dasher speed (rpm)] on the principal constituent parameters of ice cream [rate of fat destabilization (%), mean air cell diameter (mum), and mean ice crystal diameter (mum)]. A central composite face-centered design was used for this study. Thirty-one combinations of the 5 above-mentioned freezer conditions were designed (including replicates at the center point), and ice cream samples were manufactured and examined in a continuous freezer under the selected conditions. The responses were the 3 variables given above. A quadratic model was constructed, with the freezer conditions as the independent variables and the ice cream characteristics as the dependent variables. The coefficients of determination (R(2)) were greater than 0.9 for all 3 responses, but Q(2), the index used here for the capability of the model for predicting future observed values of the responses, was negative for both the mean ice crystal diameter and the mean air cell diameter. Therefore, pruned models were constructed by removing terms that had contributed little to the prediction in the original model and by refitting the regression model. It was demonstrated that these pruned models provided good fits to the data in terms of R(2), Q(2), and ANOVA. The effects of freezer conditions were expressed quantitatively in terms of the 3 responses. The drawing temperature ( degrees C) was found to have a greater effect on ice cream characteristics than any of the other factors.

Methods of bone marrow dose calculation

International Nuclear Information System (INIS)

Taboaco, R.C.

1982-02-01

Several methods of bone marrow dose calculation for photon irradiation were analised. After a critical analysis, the author proposes the adoption, by the Instituto de Radioprotecao e Dosimetria/CNEN, of Rosenstein's method for dose calculations in Radiodiagnostic examinations and Kramer's method in case of occupational irradiation. It was verified by Eckerman and Simpson that for monoenergetic gamma emitters uniformly distributed within the bone mineral of the skeleton the dose in the bone surface can be several times higher than dose in skeleton. In this way, is also proposed the Calculation of tissue-air ratios for bone surfaces in some irradiation geometries and photon energies to be included in the Rosenstein's method for organ dose calculation in Radiodiagnostic examinations. (Author) [pt

The method of local increments for the calculation of adsorption energies of atoms and small molecules on solid surfaces. Part I. A single Cu atom on the polar surfaces of ZnO.

Science.gov (United States)

Schmitt, Ilka; Fink, Karin; Staemmler, Volker

2009-12-21

The method of local increments is used in connection with the supermolecule approach and an embedded cluster model to calculate the adsorption energy of single Cu atoms at different adsorption sites at the polar surfaces of ZnO. Hartree-Fock calculations for the full system, adsorbed atom and solid surface, and for the fragments are the first step in this approach. In the present study, restricted open-shell Hartree-Fock (ROHF) calculations are performed since the Cu atom possesses a singly-occupied 4s orbital. The occupied Hartree-Fock orbitals are then localized by means of the Foster-Boys localization procedure. The correlation energies are expanded into a series of many-body increments which are evaluated separately and independently. In this way, the very time-consuming treatment of large systems is replaced with a series of much faster calculations for small subunits. In the present application, these subunits consist of the orbitals localized at the different atoms. Three adsorption situations with rather different bonding characteristics have been studied: a Cu atom atop a threefold-coordinated O atom of an embedded Zn(4)O(4) cluster, a Cu atom in an O vacancy site at the O-terminated ZnO(000-1) surface, and a Cu atom in a Zn vacancy site at the Zn-terminated ZnO(0001) surface. The following properties are analyzed in detail: convergence of the many-body expansion, contributions of the different n-body increments to the adsorption energy, treatment of the singly-occupied orbital as "localized" or "delocalized". Big savings in computer time can be achieved by this approach, particularly if only the localized orbitals in the individual increment under consideration are described by a large correlation adapted basis set, while all other orbitals are treated by a medium-size Hartree-Fock-type basis set. In this way, the method of local increments is a powerful alternative to the widely used methods like DFT or RI-MP2.

Calculation of weighted averages approach for the estimation of ping tolerance values

Science.gov (United States)

Silalom, S.; Carter, J.L.; Chantaramongkol, P.

2010-01-01

A biotic index was created and proposed as a tool to assess water quality in the Upper Mae Ping sub-watersheds. The Ping biotic index was calculated by utilizing Ping tolerance values. This paper presents the calculation of Ping tolerance values of the collected macroinvertebrates. Ping tolerance values were estimated by a weighted averages approach based on the abundance of macroinvertebrates and six chemical constituents that include conductivity, dissolved oxygen, biochemical oxygen demand, ammonia nitrogen, nitrate nitrogen and orthophosphate. Ping tolerance values range from 0 to 10. Macroinvertebrates assigned a 0 are very sensitive to organic pollution while macroinvertebrates assigned 10 are highly tolerant to pollution.

anti-inflammatory and analgesic activities: chemical constituents of ...

African Journals Online (AJOL)

a

*Corresponding author. E-mail: bedisag@yahoo.fr. ANTI-INFLAMMATORY AND ANALGESIC ACTIVITIES: CHEMICAL CONSTITUENTS OF ESSENTIAL OILS OF OCIMUM GRATISSIMUM,. EUCALYPTUS CITRIODORA AND CYMBOPOGON GIGANTEUS INHIBITED. LIPOXYGENASE L-1 AND CYCLOOXYGENASE OF ...

Response surface methodology to simplify calculation of wood energy potency from tropical short rotation coppice species

Science.gov (United States)

Haqiqi, M. T.; Yuliansyah; Suwinarti, W.; Amirta, R.

2018-04-01

Short Rotation Coppice (SRC) system is an option to provide renewable and sustainable feedstock in generating electricity for rural area. Here in this study, we focussed on application of Response Surface Methodology (RSM) to simplify calculation protocols to point out wood chip production and energy potency from some tropical SRC species identified as Bauhinia purpurea, Bridelia tomentosa, Calliandra calothyrsus, Fagraea racemosa, Gliricidia sepium, Melastoma malabathricum, Piper aduncum, Vernonia amygdalina, Vernonia arborea and Vitex pinnata. The result showed that the highest calorific value was obtained from V. pinnata wood (19.97 MJ kg-1) due to its high lignin content (29.84 %, w/w). Our findings also indicated that the use of RSM for estimating energy-electricity of SRC wood had significant term regarding to the quadratic model (R2 = 0.953), whereas the solid-chip ratio prediction was accurate (R2 = 1.000). In the near future, the simple formula will be promising to calculate energy production easily from woody biomass, especially from SRC species.

The general formulation and practical calculation of the diffusion coefficient in a lattice containing cavities; Formulation generale et calcul pratique du coefficient de diffusion dans un reseau comportant des cavites

Energy Technology Data Exchange (ETDEWEB)

Benoist, P [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

The calculation of diffusion coefficients in a lattice necessitates the knowledge of a correct method of weighting the free paths of the different constituents. An unambiguous definition of this weighting method is given here, based on the calculation of leakages from a zone of a reactor. The formulation obtained, which is both simple and general, reduces the calculation of diffusion coefficients to that of collision probabilities in the different media; it reveals in the expression for the radial coefficient the series of the terms of angular correlation (cross terms) recently shown by several authors. This formulation is then used to calculate the practical case of a classical type of lattice composed of a moderator and a fuel element surrounded by an empty space. Analytical and numerical comparison of the expressions obtained with those inferred from the theory of BEHRENS shows up the importance of several new terms some of which are linked with the transparency of the fuel element. Cross terms up to the second order are evaluated. A practical formulary is given at the end of the paper. (author) [French] Le calcul des coefficients de diffusion dans un reseau suppose la connaissance d'un mode de ponderation correct des libres parcours des differents constituants. On definit ici sans ambiguite ce mode de ponderation a partir du calcul des fuites hors d'une zone de reacteur. La formulation obtenue, simple et generale, ramene le calcul des coefficients de diffusion a celui des probabilites de collision dans les differents milieux; elle fait apparaitre dans l'expression du coefficient radial la serie des termes de correlation angulaire (termes rectangles), mis en evidence recemment par plusieurs auteurs. Cette formulation est ensuite appliquee au calcul pratique d'un reseau classique, compose d'un moderateur et d'un element combustible entoure d'une cavite; la comparaison analytique et numerique des expressions obtenues avec celles deduites de la theorie de BEHRENS

An analytical solution to calculate bulk mole fractions for any number of components in aerosol droplets after considering partitioning to a surface layer

Directory of Open Access Journals (Sweden)

D. Topping

2010-11-01

Full Text Available Calculating the equilibrium composition of atmospheric aerosol particles, using all variations of Köhler theory, has largely assumed that the total solute concentrations define both the water activity and surface tension. Recently however, bulk to surface phase partitioning has been postulated as a process which significantly alters the predicted point of activation. In this paper, an analytical solution to calculate the removal of material from a bulk to a surface layer in aerosol particles has been derived using a well established and validated surface tension framework. The applicability to an unlimited number of components is possible via reliance on data from each binary system. Whilst assumptions regarding behaviour at the surface layer have been made to facilitate derivation, it is proposed that the framework presented can capture the overall impact of bulk-surface partitioning. Demonstrations of the equations for two and five component mixtures are given while comparisons are made with more detailed frameworks capable at modelling ternary systems at higher levels of complexity. Predictions made by the model across a range of surface active properties should be tested against measurements. Indeed, reccomendations are given for experimental validation and to assess sensitivities to accuracy and required level of complexity within large scale frameworks. Importantly, the computational efficiency of using the solution presented in this paper is roughly a factor of 20 less than a similar iterative approach, a comparison with highly coupled approaches not available beyond a 3 component system.

Refinement of the list of constituents for groundwater monitoring at M-area

Energy Technology Data Exchange (ETDEWEB)

Wells, D.G.

1997-11-01

For several years Westinghouse Savannah River Company (WSRC) has been examining ways of reducing monitoring costs. Most of these efforts have been aimed at reducing the number of wells sampled or reducing sample frequency. With regards to monitoring around the M-Area Settling Basin, we are now examining a possible reduction in the number of constituents analyzed. It is our opinion that many constituents can be dropped entirely. Several others should be dropped from analyses in the plume definition wells, while retained for analyses at the point of compliance (POC) wells. Constituents that can be dropped entirely are nonhazardous inorganics generally referred to as water quality indicators. Monitoring for these parameters is sensible when a facility is in detection monitoring, but it is much less useful at a facility like the M-Area Basin. The water quality indicators are helpful in detecting whether or not a facility has impacted the environment. But their concentrations are not important in themselves. At M-Area, it is well documented that the facility has impacted groundwater quite seriously with a known group of hazardous constituents. So the concentrations of the nonhazardous constituents are of little interest. Obviously, monitoring for the hazardous constituents should continue, but it should only continue at wells that are likely to yield useful data. At M-Area there are 41 Point of Compliance (POC) wells monitoring an area of about .25 square miles and about 236 plume definition wells monitoring the surround 4 square miles. The locations of well clusters and the point of compliance are shown in figure 1. The POC wells and plume definition wells are intended to serve entirely different purposes and should not, necessarily, be monitored for the same things. The POC wells form a picket line around the facility and are intended to detect any constituents leaching from it. They are also intended to determine whether such constituents exceed action levels. Plume

Modeling of constituent redistribution in U-Pu-Zr metallic fuel

Energy Technology Data Exchange (ETDEWEB)

Kim, Yeon Soo [Argonne National Laboratory, Nuclear Engineering, RERTR, 9700 South Cass Avenue, Argonne, IL 60439 (United States)]. E-mail: yskim@anl.gov; Hayes, S.L. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States); Hofman, G.L. [Argonne National Laboratory, Nuclear Engineering, RERTR, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Yacout, A.M. [Argonne National Laboratory, Nuclear Engineering, RERTR, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

2006-12-01

A computer model was developed to analyze constituent redistribution in U-Pu-Zr metallic nuclear fuels. Diffusion and thermochemical properties were parametrically determined to fit the postirradiation data from a fuel test performed in the Experimental Breeder Reactor II (EBR-II). The computer model was used to estimate redistribution profiles of fuels proposed for the conceptual designs of small modular fast reactors. The model results showed that the level of redistribution of the fuel constituents of the designs was similar to the measured data from EBR-II.

Large-scale FMO-MP3 calculations on the surface proteins of influenza virus, hemagglutinin (HA) and neuraminidase (NA)

Science.gov (United States)

Mochizuki, Yuji; Yamashita, Katsumi; Fukuzawa, Kaori; Takematsu, Kazutomo; Watanabe, Hirofumi; Taguchi, Naoki; Okiyama, Yoshio; Tsuboi, Misako; Nakano, Tatsuya; Tanaka, Shigenori

2010-06-01

Two proteins on the influenza virus surface have been well known. One is hemagglutinin (HA) associated with the infection to cells. The fragment molecular orbital (FMO) calculations were performed on a complex consisting of HA trimer and two Fab-fragments at the third-order Møller-Plesset perturbation (MP3) level. The numbers of residues and 6-31G basis functions were 2351 and 201276, and thus a massively parallel-vector computer was utilized to accelerate the processing. This FMO-MP3 job was completed in 5.8 h with 1024 processors. Another protein is neuraminidase (NA) involved in the escape from infected cells. The FMO-MP3 calculation was also applied to analyze the interactions between oseltamivir and surrounding residues in pharmacophore.

Analysis of chemical constituents in Cistanche species.

Science.gov (United States)

Jiang, Yong; Tu, Peng-Fei

2009-03-13

Species of the genus of Cistanche (Rou Cong Rong in Chinese) are perennial parasite herbs, and are mainly distributed in arid lands and warm deserts. As a superior tonic for the treatment of kidney deficiency, impotence, female infertility, morbid leucorrhea, profuse metrorrhagia and senile constipation, Cistanche herbs earned the honor of "Ginseng of the desert". Recently, there has been increasing scientific attention on Herba Cistanche for its remarkable bioactivities including antioxidation, neuroprotection, and anti-aging. The chemical constituents of Cistanche plants mainly include volatile oils and non-volatile phenylethanoid glycosides (PhGs), iridoids, lignans, alditols, oligosaccharides and polysaccharides. Pharmacological studies show that PhGs are the main active components for curing kidney deficiency, antioxidation and neuroprotection; galactitol and oligosaccharides are the representatives for the treatment of senile constipation, while polysaccharides are responsible for improving body immunity. In this paper, the advances on the chemical constituents of Cistanche plants and their corresponding analyses are reviewed.

The Chemical Constituents and Pharmacological Actions of Cordyceps sinensis

Science.gov (United States)

Liu, Yi; Wang, Jihui; Wang, Wei; Zhang, Hanyue; Zhang, Xuelan; Han, Chunchao

2015-01-01

Cordyceps sinensis, also called DongChongXiaCao (winter worm, summer grass) in Chinese, is becoming increasingly popular and important in the public and scientific communities. This study summarizes the chemical constituents and their corresponding pharmacological actions of Cordyceps sinensis. Many bioactive components of Cordyceps sinensis have been extracted including nucleoside, polysaccharide, sterol, protein, amino acid, and polypeptide. In addition, these constituents' corresponding pharmacological actions were also shown in the study such as anti-inflammatory, antioxidant, antitumour, antiapoptosis, and immunomodulatory actions. Therefore can use different effects of C. sinensis against different diseases and provide reference for the study of Cordyceps sinensis in the future. PMID:25960753

[Study on the terpenoids of chemical constituents of Buddleja purdomii (II)].

Science.gov (United States)

Gao, Yan; Cai, Li; Li, Hai-Yan; Li, Chong

2007-06-01

To study the chemical constituents of Buddleja purdomii W. W. Smith. The constituents were isolated and purified by various chromatographic methods and structurally identified by spectral analysis. 7 compounds were obtained as luteolin (I), luteolin-7-O-beta-D-glucoside (II), trans-caffeic acid (III), cis-caffeic acid (IV), beta-stiosterol (V), stigmasterol (VI), nonacosane (VII). All these compounds are obtained from this plant for the first time.

Testing with fragrance mix. Is the addition of sorbitan sesquioleate to the constituents useful?

Science.gov (United States)

Frosch, P J; Pilz, B; Burrows, D; Camarasa, J G; Lachapelle, J M; Lahti, A; Menné, T; Wilkinson, J D

1995-05-01

In a multicentre study, the value of adding sorbitan sesquioleate (SSO) to the constituents of the 8% fragrance mix (FM) was investigated. In 7 centres, 709 consecutive patients were tested with 2 types of FM from different sources, its 8 constituents with 1% SSO, its 8 constituents without SSO, and 20% SSO. 5 patients (0.71%) reacted to the emulsifier SSO itself, read as definitely allergic on day 3/4. 53 patients reacted to either one of the mixes with an allergic type of reaction. When tested with the constituents without SSO, 41.5% showed an allergic reaction versus 54.7% with SSO. If both types of reactions were considered (allergic and irritant) 38.3% of 73 patients showed a positive "breakdown" result without SSO, versus 54.8% with SSO. The differences were statistically significant. Reactivity to FM constituents was changed in a specific pattern by addition of SSO--irritant reactions increased, particularly for cinnamic alcohol, eugenol, geraniol, oak moss and hydroxycitronellal, whereas others showed only a slight change. Allergic reactions were also increased by SSO, but the rank order of the top 3 sensitizers (isoeugenol, oak moss and eugenol) did not change. Cinnamic alcohol was the only constituent with decreased reactivity after addition of SSO. A positive history of fragrance sensitivity (HFS) was clearly associated with a positive allergic reaction to either the mix or 1 of its constituents (51% versus 28.6% with a negative HFS). Irritant reactions were linked to a negative HFS in a high proportion (64.3%).(ABSTRACT TRUNCATED AT 250 WORDS)

Double parton correlations in Light-Front constituent quark models

Directory of Open Access Journals (Sweden)

Rinaldi Matteo

2015-01-01

Full Text Available Double parton distribution functions (dPDF represent a tool to explore the 3D proton structure. They can be measured in high energy proton-proton and proton nucleus collisions and encode information on how partons inside a proton are correlated among each other. dPFDs are studied here in the valence quark region, by means of a constituent quark model, where two particle correlations are present without any additional prescription. This framework allows to understand the dynamical origin of the correlations and to clarify which, among the features of the results, are model independent. Use will be made of a relativistic light-front scheme, able to overcome some drawbacks of the previous calculation. Transverse momentum correlations, due to the exact treatment of the boosts, are predicted and analyzed. The role of spin correlations is also shown. Due to the covariance of the approach, some symmetries of the dPDFs are seen unambigously. For the valence sector, also the study of the QCD evolution of the model results, which can be performed safely thanks to the property of good support, has been also completed.

Mutations of Electrons as Constituents of Hadrons

Science.gov (United States)

Driscoll, R. B.

1997-04-01

Conjecture (C) 1: Coulomb-charged constituents of electron (e) are attracted to its barycentre by lepto-strong force F=K/r^2+f; f is stably perturbative for r Non-fiction Library, Urbana, 1986); R.M. Santilli, Hadronic Mechanics (Ukrainian Academy of Sciences, Kiev, 1995 and 1996), 3 volumes.)

Volatile constituents from Samanae saman (Jacq.) Merr. Fabaceae

African Journals Online (AJOL)

AJB SERVER

2006-10-16

Oct 16, 2006 ... Key words: Samanae saman, Fabaceae, volatile oil, fatty acids, terpenoids, palmitic acid, 1,8-cineole. .... Gas chromatography – mass spectrometry analyses (GC/MS) ... this study, is an important constituent of most vegetable.

Separation of the constituents of coal

Energy Technology Data Exchange (ETDEWEB)

Betrand, M F

1938-12-06

A process is disclosed of separating, by means of dense aqueous solutions, the constituents of coal, isolated by preliminary crushing from each other and/or from barren and carbonaceous shales, comprising the addition to the washing water before treatment or during any stage of the preparation of the coal before separation, or to the dense separating solution of agents improving the wetting of the coal by water.

Elemental Constituents of Particulate Matter and Newborn's Size in Eight European Cohorts

DEFF Research Database (Denmark)

Pedersen, Marie; Gehring, Ulrike; Beelen, Rob

2016-01-01

cohorts comprising 34,923 singleton births in 1994-2008. Annual average concentrations of elemental constituents of PM smaller than 2.5 and 10 µm (PM2.5 and PM10) at maternal home addresses during pregnancy were estimated using land-use regression models. Adjusted associations between each birth...... measurement and concentrations of eight elements (copper, iron, potassium, nickel, sulfur, silicon, vanadium and zinc) were calculated using random-effects regression on pooled data. RESULTS: A 200 ng/m(3) increase in sulfur in PM2.5 was associated with an increased risk of LBW (adjusted odds ratio, 1.36, 95......% confidence interval: 1.17, 1.58). Increased nickel and zinc in PM2.5 concentrations were also associated with an increased risk of LBW. Head circumference was reduced at higher exposure to all elements except potassium. All associations with sulfur were most robust to adjustment for PM2.5 mass concentration...

SCALE Sensitivity Calculations Using Contributon Theory

International Nuclear Information System (INIS)

Rearden, Bradley T.; Perfetti, Chris; Williams, Mark L.; Petrie, Lester M. Jr.

2010-01-01

The SCALE TSUNAMI-3D sensitivity and uncertainty analysis sequence computes the sensitivity of k-eff to each constituent multigroup cross section using adjoint techniques with the KENO Monte Carlo codes. A new technique to simultaneously obtain the product of the forward and adjoint angular flux moments within a single Monte Carlo calculation has been developed and implemented in the SCALE TSUNAMI-3D analysis sequence. A new concept in Monte Carlo theory has been developed for this work, an eigenvalue contributon estimator, which is an extension of previously developed fixed-source contributon estimators. A contributon is a particle for which the forward solution is accumulated, and its importance to the response, which is equivalent to the adjoint solution, is simultaneously accumulated. Thus, the contributon is a particle coupled with its contribution to the response, in this case k-eff. As implemented in SCALE, the contributon provides the importance of a particle exiting at any energy or direction for each location, energy and direction at which the forward flux solution is sampled. Although currently implemented for eigenvalue calculations in multigroup mode in KENO, this technique is directly applicable to continuous-energy calculations for many other responses such as fixed-source sensitivity analysis and quantification of reactor kinetics parameters. This paper provides the physical bases of eigenvalue contributon theory, provides details of implementation into TSUNAMI-3D, and provides results of sample calculations.

First-principles calculations: The elemental transition metals and their compounds

International Nuclear Information System (INIS)

Watson, R.E.; Fernando, G.W.; Weinert, M.; Davenport, J.W.

1991-01-01

If done with sufficient care, present day a priori theory yields calculated enthalpies of formation whose agreement with experiment (when such data is available) is of the order of the experimental scatter. Comparisons will be made for the Pt-Ti systems for which such data exist and for which one crystal structure involves atomics sites of low symmetry. Two other cases will be considered for which there is no direct experimental heats data. The first of these will be the structural stabilities of the 4d elemental metals. Such structural stabilities have been an issue of contention between electronic structure theorists and those who construct phase diagrams for some twenty-five years. The second involves the energetics of forming metal adlayers and artificial multilayers. The distortion energies associated with the requirement that adlayers (or multilayers) conform to some given substrate are often the controlling factors in the fabrication of multilayer materials. This contribution is best understood by invoking a combination of elemental structural promotion energies plus elastic distortions from these structures. As will be seen, the fabrication of multilayers also involves a term not normally encountered in bulk phase diagram considerations, namely the difference in surface energies of the two multilayer constituents. 22 refs., 4 figs

First-principles calculations: The elemental transition metals and their compounds

Energy Technology Data Exchange (ETDEWEB)

Watson, R.E.; Fernando, G.W.; Weinert, M.; Davenport, J.W.

1991-01-01

If done with sufficient care, present day a priori theory yields calculated enthalpies of formation whose agreement with experiment (when such data is available) is of the order of the experimental scatter. Comparisons will be made for the Pt-Ti systems for which such data exist and for which one crystal structure involves atomics sites of low symmetry. Two other cases will be considered for which there is no direct experimental heats data. The first of these will be the structural stabilities of the 4d elemental metals. Such structural stabilities have been an issue of contention between electronic structure theorists and those who construct phase diagrams for some twenty-five years. The second involves the energetics of forming metal adlayers and artificial multilayers. The distortion energies associated with the requirement that adlayers (or multilayers) conform to some given substrate are often the controlling factors in the fabrication of multilayer materials. This contribution is best understood by invoking a combination of elemental structural promotion energies plus elastic distortions from these structures. As will be seen, the fabrication of multilayers also involves a term not normally encountered in bulk phase diagram considerations, namely the difference in surface energies of the two multilayer constituents. 22 refs., 4 figs.

The reversal constituent structure of photo-electrode in dye-sensitized solar cells

International Nuclear Information System (INIS)

Ting, Chen-Ching; Chao, Wei-Shi

2011-01-01

Highlights: → The new structure of photo-electrode in DSSC increases absorption of incident photons. → The substrate of copper mesh as photo-electrode reduces electric resistance. → Application of the copper mesh as substrate reduces the fabricating cost. → There are ca. 3 times increment of photoelectric conversion efficiency. → Application of the copper mesh as substrate can achieve the flexible DSSCs. - Abstract: This article presents significant experimental data about the dye-sensitized nano solar cells (DSSCs) using the new developed photo-electrode with reversal constituent structure in our CCT laboratory. The conventional constituent structure of a photo-electrode arranged in sequence from the incident light is the transparent conductive glass, the nano TiO 2 semi-conductive porous film, and the dye. In process, the photons energy of the incident light is mainly absorbed by the dye for DSSCs. This causes excited electrons in the dye to jump into conductive band of the TiO 2 and further to transfer into the outer circuit through the conductive glass. That is, a correct constituent structure of the photo-electrode arranged in sequence from the incident light in terms of the working principle should be the dye, the nano TiO 2 film, and the conductive substrate. The conventional constituent structure of the photo-electrode causes the incident light to be hindered by the TiO 2 layer. To reduce the light hindrance for the dye, this work used copper mesh as the conductive substrate and the nano TiO 2 was coated on it. In this way, the copper mesh connects the nano TiO 2 layer with the outer circuit and the holes of the copper mesh also allow the dye to contact with the electrolyte. The new developed constituent structure of the photo-electrode arranged in sequence from the incident light is the dye, the nano TiO 2 film, and the copper mesh. This new constituent structure, which increases amounts of the absorption light in the dye and further improved the

Calculating the optical properties of defects and surfaces in wide band gap materials

Science.gov (United States)

Deák, Peter

2018-04-01

The optical properties of a material critically depend on its defects, and understanding that requires substantial and accurate input from theory. This paper describes recent developments in the electronic structure theory of defects in wide band gap materials, where the standard local or semi-local approximations of density functional theory fail. The success of the HSE06 screened hybrid functional is analyzed in case of Group-IV semiconductors and TiO2, and shown that it is the consequence of error compensation between semi-local and non-local exchange, resulting in a proper derivative discontinuity (reproduction of the band gap) and a total energy which is a linear function of the fractional occupation numbers (removing most of the electron self-interaction). This allows the calculation of electronic transitions with accuracy unseen before, as demonstrated on the single-photon emitter NV(-) center in diamond and on polaronic states in TiO2. Having a reliable tool for electronic structure calculations, theory can contribute to the understanding of complicated cases of light-matter interaction. Two examples are considered here: surface termination effects on the blinking and bleaching of the light-emission of the NV(-) center in diamond, and on the efficiency of photocatalytic water-splitting by TiO2. Finally, an outlook is presented for the application of hybrid functionals in other materials, as, e.g., ZnO, Ga2O3 or CuGaS2.

Determination of the dissolution slowness surface by study of etched shapes I. Morphology of the dissolution slowness surface and theoretical etched shapes

Science.gov (United States)

Leblois, T.; Tellier, C. R.

1992-07-01

We propose a theoretical model for the anisotropic etching of crystals, in order to be applied in the micromachining. The originality of the model is due to the introduction of dissolution tensors to express the representative surface of the dissolution slowness. The knowledge of the equation of the slowness surface allows us to determine the trajectories of all the elements which compose the starting surface. It is then possible to construct the final etched shape by numerical simulation. Several examples are given in this paper which show that the final etched shapes are correlated to the extrema of the dissolution slowness. Since the slowness surface must be determined from experiments, emphasis is placed on difficulties encountered when we correlate theory to experiments. Nous avons modélisé le processus de dissolution anisotrope des cristaux en vue d'une application à la simulation des formes obtenues par photolithogravure chimique. La principale originalité de ce modèle tient à l'introduction de tenseurs de dissolution pour exprimer la surface représentative de la lenteur de dissolution. La connaissance de l'équation de la lenteur de dissolution permet de calculer les trajectoires des différents éléments constituant la surface de départ puis de reconstituer par simulation la forme dissoute. Les simulations démontrent que les formes limites des cristaux dissous sont corrélées aux extrema de la lenteur de dissolution. La détermination de la surface de la lenteur se faisant à partir de mesures expérimetales, nous nous sommes efforcés de montrer toutes les difficultés attachées à cette analyse.

Phytochemical composition and radical scavenging activities of watermelon (Citrullus lanatus seed constituents

Directory of Open Access Journals (Sweden)

O. L. Otutu

2016-01-01

Full Text Available It is a known fact that antioxidant phytochemicals in foods have many health benefits including prevention of various diseases associated with oxidative stress such as cancer, cardiovascular disease, neuro-degeneration and diabetes. Watermelon seed constituents (whole meal, shelled and shells flours were evaluated for phytochemical components and in vitro antioxidant activity to determine the potential practical applications in food and other related areas. Antioxidant activity was investigated by measuring its DPPH (2,2-diphenyl-2-picryl hydrazyl and ABTS (2, 2’-azinobis-3-ethylbenzothiozoline- 6-sulphonic acid radical scavenging ability as well as FRAP method (ferric reducing power. Quantitative estimation of the constituents showed cardiac glycosides (9.94-14.35 mg/g and saponins (11.62-32.48 mg/g as the most concentrated phytochemicals in the constituents, while alkaloids (47.2-95.8 mg/g, total phenol (5.63-8.40 mg GAE/g, flavonoids 3.51-7.76 mg QE/g. A positive radical scavenging ability of the constituents against ABTS and DPPH free radicals ranged from 0.02 to 0.04 mg Trolox equivalent /g seed flour and 39.89 to 61.11 mg ascorbic acid equivalent /g seed flour respectively. There was a considerable ferric reducing power and higher activity was observed in whole meal than shelled seeds and shells. The significant antioxidant capacities of the seed constituents underline the potential source of natural antioxidants and bioactive compounds for therapeutic purposes.

Constituent quarks as clusters in quark-gluon-parton model. [Total cross sections, probability distributions

Energy Technology Data Exchange (ETDEWEB)

Kanki, T [Osaka Univ., Toyonaka (Japan). Coll. of General Education

1976-12-01

We present a quark-gluon-parton model in which quark-partons and gluons make clusters corresponding to two or three constituent quarks (or anti-quarks) in the meson or in the baryon, respectively. We explicitly construct the constituent quark state (cluster), by employing the Kuti-Weisskopf theory and by requiring the scaling. The quark additivity of the hadronic total cross sections and the quark counting rules on the threshold powers of various distributions are satisfied. For small x (Feynman fraction), it is shown that the constituent quarks and quark-partons have quite different probability distributions. We apply our model to hadron-hadron inclusive reactions, and clarify that the fragmentation and the diffractive processes relate to the constituent quark distributions, while the processes in or near the central region are controlled by the quark-partons. Our model gives the reasonable interpretation for the experimental data and much improves the usual ''constituent interchange model'' result near and in the central region (x asymptotically equals x sub(T) asymptotically equals 0).

The hydrogen abstraction reaction O(3P) + CH4: A new analytical potential energy surface based on fit to ab initio calculations

International Nuclear Information System (INIS)

González-Lavado, Eloisa; Corchado, Jose C.; Espinosa-Garcia, Joaquin

2014-01-01

Based exclusively on high-level ab initio calculations, a new full-dimensional analytical potential energy surface (PES-2014) for the gas-phase reaction of hydrogen abstraction from methane by an oxygen atom is developed. The ab initio information employed in the fit includes properties (equilibrium geometries, relative energies, and vibrational frequencies) of the reactants, products, saddle point, points on the reaction path, and points on the reaction swath, taking especial caution respecting the location and characterization of the intermediate complexes in the entrance and exit channels. By comparing with the reference results we show that the resulting PES-2014 reproduces reasonably well the whole set of ab initio data used in the fitting, obtained at the CCSD(T) = FULL/aug-cc-pVQZ//CCSD(T) = FC/cc-pVTZ single point level, which represents a severe test of the new surface. As a first application, on this analytical surface we perform an extensive dynamics study using quasi-classical trajectory calculations, comparing the results with recent experimental and theoretical data. The excitation function increases with energy (concave-up) reproducing experimental and theoretical information, although our values are somewhat larger. The OH rotovibrational distribution is cold in agreement with experiment. Finally, our results reproduce experimental backward scattering distribution, associated to a rebound mechanism. These results lend confidence to the accuracy of the new surface, which substantially improves the results obtained with our previous surface (PES-2000) for the same system

Shielding calculations using FLUKA

International Nuclear Information System (INIS)

Yamaguchi, Chiri; Tesch, K.; Dinter, H.

1988-06-01

The dose equivalent on the surface of concrete shielding has been calculated using the Monte Carlo code FLUKA86 for incident proton energies from 10 to 800 GeV. The results have been compared with some simple equations. The value of the angular dependent parameter in Moyer's equation has been calculated from the locations where the values of the maximum dose equivalent occur. (author)

Classification of Westminster Parliamentary constituencies using e-petition data

Directory of Open Access Journals (Sweden)

Stephen Clark

2017-08-01

Full Text Available Abstract In a representative democracy it is important that politicians have knowledge of the desires, aspirations and concerns of their constituents. Opportunities to gauge these opinions are however limited and, in the era of novel data, thoughts turn to what alternative, secondary, data sources may be available to keep politicians informed about local concerns. One such source of data are signatories to electronic petitions (e-petitions. Such e-petitions have risen greatly in popularity over the past decade and allow members of the public to initiate and sign an e-petition online, with popular e-petitions resulting in media attention, a response from the government or ultimately a debate in parliament. These data are thus novel in their availability and have not yet been widely used for research purposes. In this article we will use the e-petition data to show how semantic classes of Westminster Parliamentary constituencies, fitted as Gaussian finite mixture models via EM algorithm, can be used to typify constituencies. We identify four classes: Domestic Liberals; International Liberals; Nostalgic Brits and Rural Concerns, and illustrate how they map onto electoral results. The findings and the utility of this approach to incorporate new e-petitions and adapt to changes in electoral geography are discussed.

hispidulin and other constituents of scoparia dulcis linn

African Journals Online (AJOL)

Administrator

HIV. INTRODUCTION. Scoparia dulcis Linn. (Scrophulariaceae) has been extensively studied for its flavone and terpene constituents (Ahmed et al., 1990, Ah- san et al., 2003, Chen et al., 1976, Hayashi et al., 1987, 1987b, 1988, 1990, 1991, ...

Adsorption and dissociation of H2O on Al(1 1 1) surface by density functional theory calculation

International Nuclear Information System (INIS)

Guo, F.Y.; Long, C.G.; Zhang, J.; Zhang, Z.; Liu, C.H.; Yu, K.

2015-01-01

Highlights: • O 2 on Al(1 1 1) surface can spontaneously dissociate, but H 2 O can not. • H 2 O, OH and H on top sites are favorable on Al(1 1 1) surface. • O on the hollow (fcc) site is preferred. • O which plays a key role in the dissociate reaction of H 2 O. - Abstract: Using the first-principles calculations method based on the density functional theory, we systematically study the adsorption behavior of a single molecular H 2 O on a clean and a pre-adsorbed O atom Al(1 1 1) surface, and also its corresponding dissociation reactions. The equilibrium configuration on top, bridge, and hollow (fcc and hcp) site were determined by relaxation of the system relaxation. The adsorptions of H 2 O, OH and H on top sites are favorable on the Al(1 1 1) surface, while that of O on the hollow (fcc) site is preferred. The results show that the hydrogen atom dissociating from H 2 O needs a 248.32 kJ/mol of energy on clean Al(1 1 1) surface, while the dissociating energy decreases to 128.53 kJ/mol with the aid of the O absorption. On the other hand, these phenomena indicate that the dehydrogenated reaction energy barrier of the pre-adsorbed O on metal surface is lower than that of on a clean one, because O can promote the dehydrogenation of H 2 O

Antiparasitic, Nematicidal and Antifouling Constituents from Juniperus Berries

Science.gov (United States)

A bioassay-guided fractionation of Juniperus procera berries yielded antiparasitic, nematicidal and antifouling constituents, including a wide range of known abietane, pimarane and labdane diterpenes. Among these, abieta-7,13-diene (1) demonstrated in vitro antimalarial activity against Plasmodium f...

Evaluation of Surface Fatigue Strength Based on Surface Temperature

Science.gov (United States)

Deng, Gang; Nakanishi, Tsutomu

Surface temperature is considered to be an integrated index that is dependent on not only the load and the dimensions at the contact point but also the sliding velocity, rolling velocity, surface roughness, and lubrication conditions. Therefore, the surface durability of rollers and gears can be evaluated more exactly and simply by the use of surface temperature rather than Hertzian stress. In this research, surface temperatures of rollers under different rolling and sliding conditions are measured using a thermocouple. The effects of load P, mean velocity Vm and sliding velocity Vs on surface temperature are clarified. An experimental formula, which expresses the linear relationship between surface temperature and the P0.86Vs1.31Vm-0.83 value, is used to determine surface temperature. By comparing calculated and measured temperature on the tooth surface of a gear, this formula is confirmed to be applicable for gear tooth surface temperature calculation.

Chemical Constituents and Insecticidal Activities of Ajania fruticulosa Essential Oil.

Science.gov (United States)

Liang, Jun-Yu; Guo, Shan-Shan; You, Chun-Xue; Zhang, Wen-Juan; Wang, Cheng-Fang; Geng, Zhu-Feng; Deng, Zhi-Wei; Du, Shu-Shan; Zhang, Ji

2016-08-01

The insecticidal activity and chemical constituents of the essential oil from Ajania fruticulosa were investigated. Twelve constituents representing 91.0% of the essential oil were identified, and the main constituents were 1,8-cineole (41.40%), (+)-camphor (32.10%), and myrtenol (8.15%). The essential oil exhibited contact toxicity against Tribolium castaneum and Liposcelis bostrychophila adults with LD50 values of 105.67 μg/adult and 89.85 μg/cm(2) , respectively. The essential oil also showed fumigant toxicity against two species of insect with LC50 values of 11.52 and 0.65 mg/l, respectively. 1,8-Cineole exhibited excellent fumigant toxicity (LC50  = 5.47 mg/l) against T. castaneum. (+)-Camphor showed obvious fumigant toxicity (LC50  = 0.43 mg/l) against L. bostrychophila. Myrtenol showed contact toxicity (LD50  = 29.40 μg/cm(2) ) and fumigant toxicity (LC50  = 0.50 mg/l) against L. bostrychophila. 1,8-Cineole and (+)-camphor showed strong insecticidal activity to some important insects, and they are main constituents of A. fruticulosa essential oil. The two compounds may be related to insecticidal activity of A. fruticulosa essential oil against T. castaneum and L. bostrychophila. © 2016 Wiley-VHCA AG, Zürich.

Modeling of Alkane Oxidation Using Constituents and Species

Science.gov (United States)

Bellan, Jasette; Harstad, Kenneth G.

2010-01-01

It is currently not possible to perform simulations of turbulent reactive flows due in particular to complex chemistry, which may contain thousands of reactions and hundreds of species. This complex chemistry results in additional differential equations, making the numerical solution of the equation set computationally prohibitive. Reducing the chemical kinetics mathematical description is one of several important goals in turbulent reactive flow modeling. A chemical kinetics reduction model is proposed for alkane oxidation in air that is based on a parallel methodology to that used in turbulence modeling in the context of the Large Eddy Simulation. The objective of kinetic modeling is to predict the heat release and temperature evolution. This kinetic mechanism is valid over a pressure range from atmospheric to 60 bar, temperatures from 600 K to 2,500 K, and equivalence ratios from 0.125 to 8. This range encompasses diesel, HCCI, and gas-turbine engines, including cold ignition. A computationally efficient kinetic reduction has been proposed for alkanes that has been illustrated for n-heptane using the LLNL heptane mechanism. This model is consistent with turbulence modeling in that scales were first categorized into either those modeled or those computed as progress variables. Species were identified as being either light or heavy. The heavy species were decomposed into defined 13 constituents, and their total molar density was shown to evolve in a quasi-steady manner. The light species behave either in a quasi-steady or unsteady manner. The modeled scales are the total constituent molar density, Nc, and the molar density of the quasi-steady light species. The progress variables are the total constituent molar density rate evolution and the molar densities of the unsteady light species. The unsteady equations for the light species contain contributions of the type gain/loss rates from the heavy species that are modeled consistent with the developed mathematical

Effects of Cu intercalation on the graphene/Ni(111) surface: density-functional calculations

International Nuclear Information System (INIS)

Kwon, Se Gab; Kang, Myung Ho

2012-01-01

The Cu-intercalated graphene/Ni(111) surface has been studied by using density-functional theory calculations. We find that (1) the intercalation-induced decoupling between graphene and the Ni(111) substrate begins sharply at a Cu coverage of about 0.75 ML, (2) at the optimal Cu coverage of 1 ML, graphene recovers an almost ideal Dirac-cone band structure with no band gap, and (3) the Dirac point is located at 0.17 eV below the Fermi level, indicating a small charge transfer from the substrate. Cu thus plays essentially the same role as Au in realizing quasi-free-standing graphene by intercalation. Our charge character analysis shows that the Dirac-cone bands near the Fermi level reveal a weakening of their π character when crossing the Ni d bands, suggesting that the resulting low Dirac-cone intensity could possibly be the origin of the recent photoemission report of a relatively large band gap of 0.18 eV.

Dynamical calculations for RHEED intensity oscillations

Science.gov (United States)

Daniluk, Andrzej

2005-03-01

A practical computing algorithm working in real time has been developed for calculating the reflection high-energy electron diffraction from the molecular beam epitaxy growing surface. The calculations are based on the use of a dynamical diffraction theory in which the electrons are taken to be diffracted by a potential, which is periodic in the dimension perpendicular to the surface. The results of the calculations are presented in the form of rocking curves to illustrate how the diffracted beam intensities depend on the glancing angle of the incident beam. Program summaryTitle of program: RHEED Catalogue identifier:ADUY Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADUY Program obtainable from:CPC Program Library, Queen's University of Belfast, N. Ireland Computer for which the program is designed and others on which it has been tested: Pentium-based PC Operating systems or monitors under which the program has been tested: Windows 9x, XP, NT, Linux Programming language used: Borland C++ Memory required to execute with typical data: more than 1 MB Number of bits in a word: 64 bits Number of processors used: 1 Distribution format:tar.gz Number of lines in distributed program, including test data, etc.:982 Number of bytes in distributed program, including test data, etc.: 126 051 Nature of physical problem: Reflection high-energy electron diffraction (RHEED) is a very useful technique for studying growth and surface analysis of thin epitaxial structures prepared by the molecular beam epitaxy (MBE). Nowadays, RHEED is used in many laboratories all over the world where researchers deal with the growth of materials by MBE. The RHEED technique can reveal, almost instantaneously, changes either in the coverage of the sample surface by adsorbates or in the surface structure of a thin film. In most cases the interpretation of experimental results is based on the use of dynamical diffraction approaches. Such approaches are said to be quite useful in qualitative and

Technical activities, 1990: Surface Science Division

International Nuclear Information System (INIS)

Powell, C.J.

1991-05-01

The report summarizes technical activities and accomplishments of the NIST Surface Science Division during Fiscal Year 1990. Overviews are presented of the Division and of its three constituent groups: Surface Dynamical Processes, Thin Films and Interfaces, and Surface Spectroscopies and Standards. These overviews are followed by reports of selected technical accomplishments during the year. A summary is given of Division outputs and interactions that includes lists of publications, talks, committee assignments, seminars (including both Division seminars and Interface Science seminars arranged through the Division), conferences organized, and a standard reference material certified. Finally, lists are given of Division staff and of guest scientists who have worked in the Division during the past year

Self-assembled monolayer of ammonium pyrrolidine dithiocarbamate on copper detected using electrochemical methods, surface enhanced Raman scattering and quantum chemistry calculations

Energy Technology Data Exchange (ETDEWEB)

Liao, Q.-Q., E-mail: liaoqq1971@yahoo.com.cn [Key Lab of Shanghai Colleges and Universities for Electric Power Corrosion Control and Applied Electrochemistry, Shanghai Engineering Research Center of Energy-Saving in Heat Exchange Systems, Shanghai University of Electric Power, Shanghai 200090 (China); Yue, Z.-W.; Yang, D. [Key Lab of Shanghai Colleges and Universities for Electric Power Corrosion Control and Applied Electrochemistry, Shanghai Engineering Research Center of Energy-Saving in Heat Exchange Systems, Shanghai University of Electric Power, Shanghai 200090 (China); Wang, Z.-H. [Department of Chemistry, Tongji University, Shanghai 200092 (China); Li, Z.-H. [Department of Chemistry, Fudan University, Shanghai 200433 (China); Ge, H.-H. [Key Lab of Shanghai Colleges and Universities for Electric Power Corrosion Control and Applied Electrochemistry, Shanghai Engineering Research Center of Energy-Saving in Heat Exchange Systems, Shanghai University of Electric Power, Shanghai 200090 (China); Li, Y.-J. [Department of Chemistry, Tongji University, Shanghai 200092 (China)

2011-07-29

Ammonium pyrrolidine dithiocarbamate (APDTC) monolayer was self-assembled on fresh copper surface obtained after oxidation-reduction cycle treatment in 0.1 mol L{sup -1} potassium chloride solution at ambient temperature. The APDTC self-assembled monolayer (SAM) on copper surface was investigated by surface enhanced Raman scattering spectroscopy and the results show that APDTC SAM is chemisorbed on copper surface by its sulfur atoms with perpendicular orientation. The optimum immersing period for SAM formation is 4 h at 0.01 mol L{sup -1} concentration of APDTC. The impedance results indicate that APDTC SAM has good corrosion inhibition effects for copper in 0.5 mol L{sup -1} hydrochloric acid solution and its maximum inhibition efficiency could reach 95%. Quantum chemical calculations show that APDTC has relatively small {Delta}E between the highest occupied molecular orbital and the lowest unoccupied molecular orbital and large negative charge in its two sulfur atoms, which facilitate formation of an insulating Cu/APDTC film on copper surface.

Final disposal room structural response calculations

International Nuclear Information System (INIS)

Stone, C.M.

1997-08-01

Finite element calculations have been performed to determine the structural response of waste-filled disposal rooms at the WIPP for a period of 10,000 years after emplacement of the waste. The calculations were performed to generate the porosity surface data for the final set of compliance calculations. The most recent reference data for the stratigraphy, waste characterization, gas generation potential, and nonlinear material response have been brought together for this final set of calculations

In quest of a relativistic constituent quark model - some constructive remarks

International Nuclear Information System (INIS)

Hofsaess, T.; Schierholz, G.

1978-01-01

The set-up of a relativistic constituent quark model in four dimensions is one of the outstanding problems in particle physics. For the time being this involves a great deal of model building which, very probably, will not change in the near future. In this paper we shall offer some general remarks which might help putting such models into shape. Most of the earlier attempts are found controversial. In particular, a conventional quark constituent interpretation could not be recovered. (orig.) [de

Refinement of the list of constituents for groundwater monitoring at M-area

International Nuclear Information System (INIS)

Wells, D.G.

1997-11-01

For several years Westinghouse Savannah River Company (WSRC) has been examining ways of reducing monitoring costs. Most of these efforts have been aimed at reducing the number of wells sampled or reducing sample frequency. With regards to monitoring around the M-Area Settling Basin, we are now examining a possible reduction in the number of constituents analyzed. Constituents that can be dropped entirely are nonhazardous inorganics generally referred to as water quality indicators. Monitoring for these parameters is sensible when a facility is in detection monitoring, but it is much less useful at a facility like the M-Area Basin. The water quality indicators are helpful in detecting whether or not a facility has impacted the environment. But their concentrations are not important in themselves. At M-Area, it is well documented that the facility has impacted groundwater quite seriously with a known group of hazardous constituents. So the concentrations of the nonhazardous constituents are of little interest. At M-Area there are 41 Point of Compliance (POC) wells monitoring an area of about .25 square miles and about 236 plume definition wells monitoring the surround 4 square miles. The POC wells form a picket line around the facility and are intended to detect any constituents leaching from it. They are also intended to determine whether such constituents exceed action levels. Plume definition wells are added to define the plume created a particular set or subset of contaminants. The M-Area plume definition wells were installed in several phases over a ten year time span as SRS struggled to define the extent of a large plume of TCE and PCE. These wells were not located for the purpose of monitoring the numerous inorganics and radionuclides on the unit's monitoring list. Many of the inorganics and radionuclides are relatively immobile in groundwater and cannot be expected to appear in the widely scattered TCE/PCE plume definition wells

User's guide for SLWDN9, a code for calculating flux-surfaced-averaging of alpha densities, currents, and heating in non-circular tokamaks

International Nuclear Information System (INIS)

Hively, L.M.; Miley, G.M.

1980-03-01

The code calculates flux-surfaced-averaged values of alpha density, current, and electron/ion heating profiles in realistic, non-circular tokamak plasmas. The code is written in FORTRAN and execute on the CRAY-1 machine at the Magnetic Fusion Energy Computer Center

Constituent aspects of workplace guidance in secondary VET

NARCIS (Netherlands)

Swager, Robert; Klarus, Ruud; Van Merriënboer, Jeroen; Nieuwenhuis, Loek

2018-01-01

Purpose – This paper aims to present an integrated model of workplace guidance to enhance awareness of what constitutes good guidance, to improve workplace guidance practices in vocational education and training. Design/methodology/approach – To identify constituent aspects of workplace guidance,

[Studies on chemical constituents from leaves of Vaccinium bracteatum].

Science.gov (United States)

Li, Zeng-Liang; Zhang, Lin; Tian, Jing-Kui; Zhou, Wen-Ming

2008-09-01

To investigate the chemical constituents from the leaves of Vaccinium bracteatum. Many column chromatographic techniques were used for the isolation and separation of chemical constituents. Their structures were elucidated on the basis of spectral analysis and chemical evidences. Twelve compounds were isolated from the plant, and they were identified as chrysoeriol (1), scopoletin (2), trans-p-hydroxycinnamic acid (3), trans-p-hydroxycinnamic acid ethyl ester (4), cafeic acid ethyl ester (5), beta-sitosterol (6), iuteolin (7), quercetin (8), esculetin (9), cafeic acid (10), isolariciresinol-9-O-beta-D-xyloside (11), 10-O-trans-p-coumaroylsandoside (12). Compounds 4, 5, 11, 12 were isolated from the genus Vaccinium for the first time, and compounds 1, 2, 9, 10 were isolated from this plant for the first time.

Antibacterial activity of chemical constituents isolated from Asparagus racemosus

Directory of Open Access Journals (Sweden)

Muhammad Abdullah Shah

2014-03-01

Full Text Available Asparagus racemosus is a medical extensively used in traditional medicine for various disorders including its use in infectious. So far work has been done to identify its active constituents responsible for antiseptic folk use of this plant. In the current investigation, we have made an effort to identify its chemical constituents that might be partly responsible for antimicrobial properties. Extraction and isolation of plant extract lead to isolation of two nor-lignans and two steroidal triterpenes (compound 1 to 4. All compound showed considerable antibacterial activities against E. coli and S. aureus while no significant activity was observed against S. typhi. This study highlighted the potential of A. racemosus to be further explored as a source of bioactive natural products.

Methods of removing a constituent from a feed stream using adsorption media

Science.gov (United States)

Tranter, Troy J [Idaho Falls, ID; Mann, Nicholas R [Rigby, ID; Todd, Terry A [Aberdeen, ID; Herbst, Ronald S [Idaho Falls, ID

2011-05-24

A method of producing an adsorption medium to remove at least one constituent from a feed stream. The method comprises dissolving and/or suspending at least one metal compound in a solvent to form a metal solution, dissolving polyacrylonitrile into the metal solution to form a PAN-metal solution, and depositing the PAN-metal solution into a quenching bath to produce the adsorption medium. The at least one constituent, such as arsenic, selenium, or antimony, is removed from the feed stream by passing the feed stream through the adsorption medium. An adsorption medium having an increased metal loading and increased capacity for arresting the at least one constituent to be removed is also disclosed. The adsorption medium includes a polyacrylonitrile matrix and at least one metal hydroxide incorporated into the polyacrylonitrile matrix.

Volatile constituents of Ocotea sinuata (Mez) Rohwer (Lauraceae) of Costa Rica

International Nuclear Information System (INIS)

Hernandez, Lorena; Ciccio, Jose F.; Chaverri, Carlos

2007-01-01

The chemical composition was determined of the essential oils extracted from twigs, bark and leaves of the tree Ocotea sinuata (Mez) Rohwer (Lauraceae), which grows in wild form in Costa Rica. The analyses were effected by means of the technology of gas chromatography in capillary column, using detectors of ionization at flame (FID) and spectrometry of masses (GC/MS). Eighty eight (88) compounds were identified. The oils were found to be of nature terpenic. The major constituents of the twigs were β-caryophyllene (18,4%), viridiflorol (11,3%), caryophyllene oxide (8,7%), germacrene D (7,7%), camphene (4,5%), and α-pinene (4,4%). The main constituents from bark oil were germacrene D (14.8%), β- caryophyllene(10,5%), camphene (10,3%), α-pinene (10,1%), viridiflorol (8,7%), β-pinene (4,7%) and α-copaene (4,6%). The main constituents from leaf oil were germacrene D (30,6%), β- caryophyllene (30,1%) and viridiflorol (8,9%). (author) [es

Studies on chemical constituents of Polygala japonica Houtt.

Institute of Scientific and Technical Information of China (English)

LI Ting-zhao; ZHANG Wei-dong; LIU Run-hui; CHEN Hai-sheng; ZHANG Chuan; SU Juan; XU Xi-ke

2006-01-01

Objective:To investigate the chemical constituents of Polygala japonica Houtt.. Methods:The constituents were separated and purified by column chromatographies with silical gel, RP-silical gel and Sephadex LH-20. Their structures were elucidated on the basis of spectral data (IR, MS, 1H-NMR, 13C-NMR, HMQC and HMBC). Results: Totally 15 compounds were obtained from Polygala japonica Houtt. And their structures were identified as castaprenol-12 (Ⅰ), β-sitosterol (Ⅱ), stigmasterol (Ⅲ),stigmasta-7,22-di-ene-3-one (Ⅳ), n-dotriacontanol ( Ⅴ ), n-hexadecanol ( Ⅵ ), arachidic acid (Ⅶ), erogosterol (Ⅷ), kaempferol (Ⅸ), quercetin (Ⅹ), daucosterol (Ⅺ), p-hydroxybenzoic acid (Ⅻ),coumaric acid (ⅩⅢ), rhamnocitrin 3-O-β-D-galactopyranoside (ⅪⅤ), quercetin 3-O-β-D-glucopyranoside (ⅩⅤ). Conclusion: Compounds Ⅰ , Ⅲ , Ⅳ, Ⅴ , Ⅵ, Ⅶ, Ⅷ, Ⅻ , ⅩⅢ and ⅩⅣ were obtained from this plant for the first time.

Polar constituents isolated from Green River oil shale

Energy Technology Data Exchange (ETDEWEB)

Anders, D.E.; Doolittle, F.G.; Robinson, W.E.

1975-01-01

The mass spectrometric, ir absorption, and NMR data were interpreted for 22 compounds obtained from a polar fraction of Green River shale. The major constituents analyzed are believed to be of the following compositional types: C/sub n/H/sub 2n/O (cyclohexanols and chain isoprenoid ketones), C/sub n/H/sub 2n-10/O (tetralones and indanones), C/sub n/H/sub 2n-7/N (tetrahydroquinolines), C/sub n/H/sub 2n-11/N(quinolines), C/sub n/H/sub 2n-1/NO (alkoxypyrrolines), C/sub n/H/sub 2n-5/NO/sub 2/ (maleimides), C/sub n/H/sub 2n-8/ (tetralins), C/sub n/H/sub 2n-12/ (naphthalenes) and C/sub n/H/sub 2n-14/ (benzylbenzenes). This work expands the present information about nitrogen, oxygen and aromatic constituents indigenous to Green River shale.

OCA-II, a code for calculating the behavior of 2-D and 3-D surface flaws in a pressure vessel subjected to temperature and pressure transients

International Nuclear Information System (INIS)

Ball, D.G.; Drake, J.B.; Cheverton, R.D.; Iskander, S.K.

1984-02-01

The OCA-II computer code, like its predecessor OCA-I, performs the thermal, stress, and linear elastic fracture-mechanics analysis for long flaws on the surface of a cylinder that is subjected to thermal and pressure transients. OCA-II represents a revised and expanded version of OCA-I and includes as new features (1) cladding as a discrete region, (2) a finite-element subroutine for calculating the stresses, and (3) the ability to calculate stress intensity factors for certain three-dimensional flaws, for two-dimensional circumferential flaws on the inner surface, and for both axial and circumferential flaws on the outer surface. OCA-I considered only inner-surface flaws. An option is included in OCA-II that permits a search for critical values of fluence or nil-ductility reference temperature corresponding to a specified failure criterion. These and other features of OCA-II are described in the report, which also includes user instructions for the code

The cellular approach to band structure calculations

International Nuclear Information System (INIS)

Verwoerd, W.S.

1982-01-01

A short introduction to the cellular approach in band structure calculations is given. The linear cellular approach and its potantial applicability in surface structure calculations is given some consideration in particular

Build-up and surface dose measurements on phantoms using micro-MOSFET in 6 and 10 MV x-ray beams and comparisons with Monte Carlo calculations

International Nuclear Information System (INIS)

Xiang, Hong F.; Song, Jun S.; Chin, David W. H.; Cormack, Robert A.; Tishler, Roy B.; Makrigiorgos, G. Mike; Court, Laurence E.; Chin, Lee M.

2007-01-01

This work is intended to investigate the application and accuracy of micro-MOSFET for superficial dose measurement under clinically used MV x-ray beams. Dose response of micro-MOSFET in the build-up region and on surface under MV x-ray beams were measured and compared to Monte Carlo calculations. First, percentage-depth-doses were measured with micro-MOSFET under 6 and 10 MV beams of normal incidence onto a flat solid water phantom. Micro-MOSFET data were compared with the measurements from a parallel plate ionization chamber and Monte Carlo dose calculation in the build-up region. Then, percentage-depth-doses were measured for oblique beams at 0 deg. - 80 deg. onto the flat solid water phantom with micro-MOSFET placed at depths of 2 cm, 1 cm, and 2 mm below the surface. Measurements were compared to Monte Carlo calculations under these settings. Finally, measurements were performed with micro-MOSFET embedded in the first 1 mm layer of bolus placed on a flat phantom and a curved phantom of semi-cylindrical shape. Results were compared to superficial dose calculated from Monte Carlo for a 2 mm thin layer that extends from the surface to a depth of 2 mm. Results were (1) Comparison of measurements with MC calculation in the build-up region showed that micro-MOSFET has a water-equivalence thickness (WET) of 0.87 mm for 6 MV beam and 0.99 mm for 10 MV beam from the flat side, and a WET of 0.72 mm for 6 MV beam and 0.76 mm for 10 MV beam from the epoxy side. (2) For normal beam incidences, percentage depth dose agree within 3%-5% among micro-MOSFET measurements, parallel-plate ionization chamber measurements, and MC calculations. (3) For oblique incidence on the flat phantom with micro-MOSFET placed at depths of 2 cm, 1 cm, and 2 mm, measurements were consistent with MC calculations within a typical uncertainty of 3%-5%. (4) For oblique incidence on the flat phantom and a curved-surface phantom, measurements with micro-MOSFET placed at 1.0 mm agrees with the MC

A computer code 'BEAM' for the ion optics calculation of the JAERI tandem accelerator system

International Nuclear Information System (INIS)

Kikuchi, Shiroh; Takeuchi, Suehiro

1987-11-01

The computer code BEAM is described, together with an outline of the formalism used for the ion optics calculation. The purpose of the code is to obtain the optimum parameters of devices, with which the ion beam is transported through the system without losses. The procedures of the calculation, especially those of searching for the parameters of quadrupole lenses, are discussed in detail. The flow of the code is illustrated as a whole and its constituent subroutines are explained individually. A few resultant beam trajectories and the parameters used to obtain them are shown as examples. (author)

Tensor Susceptibilities of the Vacuum from Constituent Quarks

International Nuclear Information System (INIS)

Broniowski, W.; Polyakov, M.; Goeke, K.; Hyun-Chul Kim

1998-01-01

We show that the constituent quark model leads to simple expression for the isoscalar and isovector tensor susceptibilities of the vacuum. The found values are negative and of magnitude compatible with QCD-sum-rule parametrizations of spectral densities in appropriate L=1-meson channels. (author)

Tensor Susceptibilities of the Vacuum from Constituent Quarks

Energy Technology Data Exchange (ETDEWEB)

Broniowski, W [The H. Niewodniczanski Institute of Nuclear Physics, Cracow (Poland); Polyakov, M; Goeke, K [Institute for Theoretical Physics II, Ruhr-Universitaet-Bochum, Bochum (Germany); Kim, Hyun-Chul [Pusan National University, Department of Physics, Pusan (Korea, Republic of)

1998-05-15

We show that the constituent quark model leads to simple expression for the isoscalar and isovector tensor susceptibilities of the vacuum. The found values are negative and of magnitude compatible with QCD-sum-rule parametrizations of spectral densities in appropriate L=1-meson channels. (author)

Ethnopharmacological Investigations of Phytochemical Constituents Isolated from the Genus Cuscuta.

Science.gov (United States)

Ibrahim, Muhammad; Rehman, Kanwal; Hussain, Iqbal; Farooq, Tahir; Ali, Bisharat; Majeed, Irum; Akash, Muhammad Sajid Hamid

2017-01-01

The genus Cuscuta, of the family Cuscutaceae, is present in plants and has been traditionally used medicinally against many diseases and conditions, notably depression, mental illness, headache, spleen disease, jaundice, diabetes mellitus, and hypertension. Large numbers of phytochemical constituents such as alkaloids, flavonoids, lignins, oxygen heterocyclic compounds, steroids, fatty acids, phenolic acids, resin glycosides, and polysaccharides have been isolated from different species of Cuscuta. Ethnopharmacological studies conducted on such constituents have also been shown Cuscuta to possess anticancer, antiviral, antispasmodic, antihypertensive, anticonvulsant, antibacterial, antioxidant, diuretic, and hair-growth activity. Many tribes and traditional communities have long used the different forms of Cuscuta for treatment and prevention of many diseases. In this article, we comprehensively summarize relevant data regarding the phytochemical, ethnopharmacological, and traditional therapeutic uses of Cuscuta. In addition, we review the parts of the plants that are used as traditional therapeutic agents, their regions of existence, and their possible modes of action. To conclude, we provide evidence and new insights for further discovery and development of natural drugs from Cuscuta. We show that further studies are needed to investigate the mechanism of action and safety profile of phytochemical constituents isolated from Cuscuta.

The use of stable isotopes to trace oil sands constituents

International Nuclear Information System (INIS)

Farwell, A.J.; Nero, V.; Dixon, D.G.

2002-01-01

A study was conducted to determine the biological effects of oil sands mining operations on aquatic ecosystems. The study focused on the Athabasca oil sand deposit, the largest of 4 deposits in northern Alberta. In particular, the study examined the cycling of oil sand constituents in Benthic invertebrates collected from test pits at Syncrude Canada Ltd.. The invertebrates were similar in size, but different in the quantity of process-affected water or mature fine tailings containing residual bitumen. Dragonflies and damselflies in particular, showed trends of depletion for the carbon 13 isotope and enrichment in nitrogen 15 isotope in pits where levels of process affected water was high. The depletion of carbon 13 isotope suggests that oil sand constituents assimilate into the benthic food chain. The greatest carbon 13 depletion, which was approximately 27 per cent, was found to be in test pits with high turbidity. This implies that oil sands constituents degrade microbially instead of by photosynthetic production. All benthic invertebrate group demonstrated an incremental enrichment in nitrogen 15 isotope from the control pit to the pit with greatest levels of mature fine tailings

An extract of a formula used in the traditional chinese medicine (Buzhong Yi Qi Wan) alters the labeling of blood constituents with technetium-99m

International Nuclear Information System (INIS)

Giani, Tania Santos; Paoli, Severo de; Brandao-Neto, Jose; Medeiros, Aldo da Cunha; Presta, Giuseppe Antonio; Maiworm, Adalgisa Ieda; Santos Filho, Sebastiao David; Fonseca, Adenilson de Souza da; Bernardo-Filho, Mario

2007-01-01

Buzhong Yi Qi Wan (Buzhong) is a medicinal herb widely used in Traditional Chinese Medicine to treat the digestive and circulatory systems. Red blood cell and plasma proteins labeled with technetium-99m ( 99m Tc) are used in nuclear medicine. The aim of this work was to investigate the effects of an aqueous Buzhong extract on the labeling of blood constituents with 99m Tc. Heparinized blood (Wistar rats) was incubated in vitro with different Buzhong extract concentrations and 99m Tc-labeling was performed. Plasma (P) and blood cells (BC) were separated and soluble (SF-P, SF-BC) and insoluble (IF-P, IF-BC) fractions were isolated. The radioactivity on blood constituents was determined and the percentage of incorporated radioactivity (%ATI) was calculated. Buzhong extract at the highest concentrations used altered significantly (p 99 mTc. (author)

75 FR 33814 - Tobacco Product Constituents Subcommittee of the Tobacco Products Scientific Advisory Committee...

Science.gov (United States)

2010-06-15

...] Tobacco Product Constituents Subcommittee of the Tobacco Products Scientific Advisory Committee; Notice of... to the public. Name of Committee: Tobacco Product Constituents Subcommittee of the Tobacco Products...-8900. Contact Person: Karen Templeton-Somers, Office of Science, Center for Tobacco Products, Food and...

Adsorption of SO{sub 2} on Li atoms deposited on MgO (1 0 0) surface: DFT calculations

Energy Technology Data Exchange (ETDEWEB)

Eid, Kh.M., E-mail: Kheid98@hotmail.com [Physics Department, Faculty of Education, Ain Shams University, Cairo 11757 (Egypt); Ammar, H.Y. [Department of Physics, Faculty of Science, Najran University, Najran 1988 (Saudi Arabia)

2011-05-01

The adsorption of sulfur dioxide molecule (SO{sub 2}) on Li atom deposited on the surfaces of metal oxide MgO (1 0 0) on both anionic and defect (F{sub s}-center) sites located on various geometrical defects (terrace, edge and corner) has been studied using density functional theory (DFT) in combination with embedded cluster model. The adsorption energy (E{sub ads}) of SO{sub 2} molecule (S-atom down as well as O-atom down) in different positions on both of O{sup -2} and F{sub s} sites is considered. The spin density (SD) distribution due to the presence of Li atom is discussed. The geometrical optimizations have been done for the additive materials and MgO substrate surfaces (terrace, edge and corner). The oxygen vacancy formation energies have been evaluated for MgO substrate surfaces. The ionization potential (IP) for defect free and defect containing of the MgO surfaces has been calculated. The adsorption properties of SO{sub 2} are analyzed in terms of the E{sub ads}, the electron donation (basicity), the elongation of S-O bond length and the atomic charges on adsorbed materials. The presence of the Li atom increases the catalytic effect of the anionic O{sup -2} site of MgO substrate surfaces (converted from physisorption to chemisorption). On the other hand, the presence of the Li atom decreases the catalytic effect of the F{sub s}-site of MgO substrate surfaces. Generally, the SO{sub 2} molecule is strongly adsorbed (chemisorption) on the MgO substrate surfaces containing F{sub s}-center.

Characterization of the Fermi surface of BEDT-TTF4[Hg2Cl6].PhCl by electronic band structure calculations

International Nuclear Information System (INIS)

Veiros, L.F.; Canadell, E.

1994-01-01

Tight-binding band structure calculations for the room temperature structure of BEDT-TTF 4 [Hg 2 Cl 6 ]-PhCl show the existence of closed electron and hole Fermi surfaces, in agreement with the 2D metallic conductivity of this salt. It is shown that these closed Fermi surfaces result from the hybridization of two hidden 1D Fermi surfaces. However, our study also shows that a transition associated with either a usual or a hidden nesting type mechanism is unlikely. This explains why this salt retains its metallic properties without any resistivity anomaly down to 1.3 K. Our study suggests that BEDT-TTF 4 [Hg 2 Cl 6 ]-PhCl is somewhat anisotropic 2D semimetal and should exhibit Shubnikov-de Haas oscillations corresponding to a cross-sectional area of approximately 13% of the first Brillouin zone. (orig.)

Constituent quark model for nuclear stopping in high energy nuclear collisions

International Nuclear Information System (INIS)

Choi, T.K.; Maruyama, M.; Takagi, F.

1997-01-01

We study nuclear stopping in high energy nuclear collisions using the constituent quark model. It is assumed that wounded nucleons with a different number of interacted quarks hadronize in different ways. The probabilities of having such wounded nucleons are evaluated for proton-proton, proton-nucleus, and nucleus-nucleus collisions. After examining our model in proton-proton and proton-nucleus collisions and fixing the hadronization functions, it is extended to nucleus-nucleus collisions. It is used to calculate the rapidity distribution and the rapidity shift of final-state protons in nucleus-nucleus collisions. The computed results are in good agreement with the experimental data on 32 S+ 32 S at E lab =200A GeV and 208 Pb+ 208 Pb at E lab =160A GeV. Theoretical predictions are also given for proton rapidity distribution in 197 Au+ 197 Au at √(s)=200A GeV (BNL-RHIC). We predict that the nearly baryon-free region will appear in the midrapidity region and the rapidity shift is left-angle Δy right-angle=2.24

High Accuracy Potential Energy Surface, Dipole Moment Surface, Rovibrational Energies and Line List Calculations for ^{14}NH_3

Science.gov (United States)

Coles, Phillip; Yurchenko, Sergei N.; Polyansky, Oleg; Kyuberis, Aleksandra; Ovsyannikov, Roman I.; Zobov, Nikolay Fedorovich; Tennyson, Jonathan

2017-06-01

We present a new spectroscopic potential energy surface (PES) for ^{14}NH_3, produced by refining a high accuracy ab initio PES to experimental energy levels taken predominantly from MARVEL. The PES reproduces 1722 matched J=0-8 experimental energies with a root-mean-square error of 0.035 cm-1 under 6000 cm^{-1} and 0.059 under 7200 cm^{-1}. In conjunction with a new DMS calculated using multi reference configuration interaction (MRCI) and H=aug-cc-pVQZ, N=aug-cc-pWCVQZ basis sets, an infrared (IR) line list has been computed which is suitable for use up to 2000 K. The line list is used to assign experimental lines in the 7500 - 10,500 cm^{-1} region and previously unassigned lines in HITRAN in the 6000-7000 cm^{-1} region. Oleg L. Polyansky, Roman I. Ovsyannikov, Aleksandra A. Kyuberis, Lorenzo Lodi, Jonathan Tennyson, Andrey Yachmenev, Sergei N. Yurchenko, Nikolai F. Zobov, J. Mol. Spec., 327 (2016) 21-30 Afaf R. Al Derzia, Tibor Furtenbacher, Jonathan Tennyson, Sergei N. Yurchenko, Attila G. Császár, J. Quant. Spectrosc. Rad. Trans., 161 (2015) 117-130

Atmospheric and surface properties of Mars obtained by infrared spectroscopy on Mariner 9

Science.gov (United States)

Conrath, B.; Curran, R.; Hanel, R.; Kunde, V.; Maguire, W.; Pearl, J.; Pirraglia, J.; Welker, J.; Burke, T.

1973-01-01

The infrared spectroscopy experiment on Mariner 9 obtained data over much of Mars. Interpretation of the thermal emission of Mars in terms of atmospheric temperatures, wind fields and dynamics, surface temperatures, surface pressure and topography, mineral composition, and minor atmospheric constituents including isotopic ratios, as well as a search for unexpected phenomena are reported.

Bio-Functional Constituents from the Stems of Liriodendron tulipifera

Directory of Open Access Journals (Sweden)

Chung-Yi Chen

2012-04-01

Full Text Available Four known compounds have been isolated from the stems of Liriodendron tulipifera, and the structures of these pure constituents were determined using spectroscopic analysis. Isolated compounds were screened for free radical scavenging ability, metal chelating power assay and ferric reducing antioxidant power assay (FRAP. The anti-tyrosinase effects of L. tulipifera compounds were calculated the inhibition of hydroxylation of L-tyrosine to L-dopa according to an in vitro mushroom tyrosinase assay. The study also examined the bio-effects of the four compounds on the human melanoma A375.S2, and showed that liriodenine (1 and (--norglaucine (4 significantly inhibited the proliferation of melanoma cells in the cell viability assay. Wound healing results indicated that liriodenine (1, (--glaucine (3 and (--norglaucine (4 exerted anti-migration potential. Interestingly, (--glaucine (3, neither liriodenine (1 nor (--norglaucine (4 showed promising anti-migration potential without inducing significant cytotoxicity. Furthermore, a dramatically increased level of intracellular reactive oxygen species (ROS was detected from (--glaucine (3. The cell cycle assessment demonstrated a moderate G2/M accumulation by (--glaucine (3. The above results revealed the anti-cancer effects of L. tulipifera compounds, especially on the anti-migration ability indicating the promising chemopreventive agents to human skin melanoma cells.

Constituent quark mass and nucleon properties in nuclei

International Nuclear Information System (INIS)

Beyer, M.; Singh, S.K.

1986-01-01

It is shown that the Nolen-Schiffer anomaly, the quenching of gsub(A) and the increase in some electromagnetic properties of nucleons in nuclei can all be explained qualitatively in a constituent quark model if the quark mass is assumed to depend on its confinement size. (author)

Mossbauer analysis of Luna 16 lunar surface material

Science.gov (United States)

Nady, D. L.; Cher, L.; Kulcsar, K.

1974-01-01

Samples of Apollo 11 lunar surface material were studied by the Mossbauer effect. Owing to the small number of other resonant isotopes, all measurements were made with Fe-57 nuclei. The principal constituents of the material were as follows: Iron containing silicates (olivine, pyroxene, and so on), ilmenite (FeTiO3), and metallic iron.

Not Just a Sum? Identifying Different Types of Interplay between Constituents in Combined Interventions.

Science.gov (United States)

Van Deun, Katrijn; Thorrez, Lieven; van den Berg, Robert A; Smilde, Age K; Van Mechelen, Iven

2015-01-01

Experiments in which the effect of combined manipulations is compared with the effects of their pure constituents have received a great deal of attention. Examples include the study of combination therapies and the comparison of double and single knockout model organisms. Often the effect of the combined manipulation is not a mere addition of the effects of its constituents, with quite different forms of interplay between the constituents being possible. Yet, a well-formalized taxonomy of possible forms of interplay is lacking, let alone a statistical methodology to test for their presence in empirical data. Starting from a taxonomy of a broad range of forms of interplay between constituents of a combined manipulation, we propose a sound statistical hypothesis testing framework to test for the presence of each particular form of interplay. We illustrate the framework with analyses of public gene expression data on the combined treatment of dendritic cells with curdlan and GM-CSF and show that these lead to valuable insights into the mode of action of the constituent treatments and their combination. R code implementing the statistical testing procedure for microarray gene expression data is available as supplementary material. The data are available from the Gene Expression Omnibus with accession number GSE32986.

The European Constitution: sovereignty, legitimacy and constituent power

Directory of Open Access Journals (Sweden)

Signe Larsen

2014-06-01

Full Text Available On the basis of Hannah Arendt’s and Carl Schmitt’s writings on the constituent power, this article sets out to develop an interpretative framework which would aid the understanding of the legitimation crisis of European integration initiated by the EU constitutional failure of 2004. The question raised in this essay is whether the successful establishment of democratic constitutional legitimacy is conditional upon the existence of a federal state. From the perspective of the constituent power, two opposing answers are given based on two rivalling notions of the ultimate meaning of constitutional politics: freedom and security. The article concludes that even though the EU as a case remains undecided, it seems likely that democracy and constitutional politics have parted ways in the EU both in the Arendtian and in the Schmittian sense. If that is the case, the constitutional crisis is a serious problem for the future of democracy in the EU.

Hydrogen atom injection into carbon surfaces by comparison between Monte-Carlo, molecular dynamics and ab-initio calculations

International Nuclear Information System (INIS)

Ito, A.; Kenmotsu, T.; Kikuhara, Y.; Inai, K.; Ohya, K.; Wang, Y.; Irle, S.; Morokuma, K.; Nakamura, H.

2009-01-01

Full text: To understand the plasma-wall interaction on divertor plates, we investigate the interaction of hydrogen atoms and carbon materials used in the high heat flux components by the use of the following simulations. Monte-Carlo (MC) method based on binary collision approximation can calculate the sputtering process of hydrogen atoms on the carbon material quickly. Classical molecular dynamics (MD) method employs multi-body potential models and can treat realistic structures of crystal and molecule. The ab-initio method can calculate electron energy in quantum mechanics, which is regarded as realistic potential for atoms. In the present paper, the interaction of the hydrogen and the carbon material is investigated using the multi-scale (MC, MD and ab-initio) methods. The bombardment of hydrogen atoms onto the carbon material is simulated by the ACAT-code of the MC method, which cannot represent the structure of crystal, and the MD method using modified reactive empirical bond order (REBO) potential, which treats single crystal graphite and amorphous carbon. Consequently, we clarify that the sputtering yield and the reflection rate calculated by the ACAT-code agree with those on the amorphous carbon calculated by the MD. Moreover, there are many kinds of REBO potential for the MD. Adsorption, reflection and penetration rates between a hydrogen atom and a graphene surface are calculated by the MD simulations using the two kinds of potential model. For the incident energy of less than 1 eV, the MD simulation using the modified REBO potential, which is based on Brenner's REBO potential in 2002, shows that reflection is dominant, while the most popular Brenner's REBO potential in 1990 shows that adsorption is dominant. This reflection of the low energy injection is caused by a small potential barrier for the hydrogen atom in the modified REBO potential. The small potential barrier is confirmed by the ab-initio calculations, which are hybrid DFT (B3LYP/cc-pVDZ), ab

Effects of surface stability on the morphological transformation of metals and metal oxides as investigated by first-principles calculations.

Science.gov (United States)

Andrés, Juan; Gracia, Lourdes; Gouveia, Amanda Fernandes; Ferrer, Mateus Meneghetti; Longo, Elson

2015-10-09

Morphology is a key property of materials. Owing to their precise structure and morphology, crystals and nanocrystals provide excellent model systems for joint experimental and theoretical investigations into surface-related properties. Faceted polyhedral crystals and nanocrystals expose well-defined crystallographic planes depending on the synthesis method, which allow for thoughtful investigations into structure-reactivity relationships under practical conditions. This feature article introduces recent work, based on the combined use of experimental findings and first-principles calculations, to provide deeper knowledge of the electronic, structural, and energetic properties controlling the morphology and the transformation mechanisms of different metals and metal oxides: Ag, anatase TiO2, BaZrO3, and α-Ag2WO4. According to the Wulff theorem, the equilibrium shapes of these systems are obtained from the values of their respective surface energies. These investigations are useful to gain further understanding of how to achieve morphological control of complex three-dimensional crystals by tuning the ratio of the surface energy values of the different facets. This strategy allows the prediction of possible morphologies for a crystal and/or nanocrystal by controlling the relative values of surface energies.

Analysis of chemical constituents in medicinal plants of selected ...

African Journals Online (AJOL)

Analysis of chemical constituents in medicinal plants of selected districts of Pakhtoonkhwa, Pakistan. I Hussain, R Ullah, J Khan, N Khan, M Zahoor, N Ullah, MuR Khattak, FA Khan, A Baseer, M Khurram ...

Effects of fine particulate matter and its constituents on low birth weight among full-term infants in California

International Nuclear Information System (INIS)

Basu, Rupa; Harris, Maria; Sie, Lillian; Malig, Brian; Broadwin, Rachel; Green, Rochelle

2014-01-01

Relationships between prenatal exposure to fine particles (PM 2.5 ) and birth weight have been observed previously. Few studies have investigated specific constituents of PM 2.5 , which may identify sources and major contributors of risk. We examined the effects of trimester and full gestational prenatal exposures to PM 2.5 mass and 23 PM 2.5 constituents on birth weight among 646,296 term births in California between 2000 and 2006. We used linear and logistic regression models to assess associations between exposures and birth weight and risk of low birth weight (LBW; 2.5 mass and several PM 2.5 constituents were significantly associated with reductions in term birth weight. The largest reductions in birth weight were associated with exposure to vanadium, sulfur, sulfate, iron, elemental carbon, titanium, manganese, bromine, ammonium, zinc, and copper. Several of these PM 2.5 constituents were associated with increased risk of term LBW. Reductions in birth weight were generally larger among younger mothers and varied by race/ethnicity. Exposure to specific constituents of PM 2.5 , especially traffic-related particles, sulfur constituents, and metals, were associated with decreased birth weight in California. -- Highlights: • Examine full gestational and trimester fine particle and its constituents on term birth weight. • Fine particles and several of its constituents associated with birth weight reductions. • Largest reductions for traffic-related particles, sulfur constituents, and metals. • Greater birth weight reductions for younger mothers, and varied by race/ethnicity

Patch testing with constituents of Compositae mixes.

Science.gov (United States)

Paulsen, Evy; Andersen, Klaus E

2012-05-01

The development of mixes containing Compositae plant extracts has improved the diagnosis of Compositae contact allergy, but none of them has fulfilled the criteria for an ideal European plant mix. To evaluate which constituents of two commercial Compositae mixes were most useful as screening agents. These comprised 76 patients testing positive to Compositae mix 6% in petrolatum and 29 patients testing positive to Compositae mix 5% pet., all of whom were tested with constituents of the respective mixes. The majority of patients tested positive to parthenolide or parthenolide-containing extracts, followed by German chamomile, yarrow, and arnica. As German chamomile is a weak sensitizer, the results suggest cross-reactions or reactions to unknown allergens. No one was positive to Roman chamomile. Even though parthenolide seems to be a suitable supplement to the baseline series, the results emphasize that it is important to patch test with extracts of native or locally grown plants, not only because of the geographical variation, but also because of the potential unknown allergens contained in short ether preparations and the variability in the individual patient's exposure and cross-reaction patterns. © 2012 John Wiley & Sons A/S.

ASSESSING UNIVERSITY RESEARCH PERFORMANCE WITH MULTIPLE CONSTITUENCIES

Directory of Open Access Journals (Sweden)

Kuang-Liang Liu

2012-12-01

Full Text Available The research performance of the university is critical to the national competitiveness. Previous research has established that research performance is based on scholarly publishing. Several studies suggested that journal ranking is the important research quality indicator. However, unilateral measurement for the research performance will seriously corrode the development of university research work. Assessing university research performance with multiple constituencies is a better to enhance the university research. Although substantial studies have been performed on the critical factors that affect knowledge exploration in the university, those in knowledge exploitation are still lacking. With the multiple constituencies, a fully understanding of research performance can be gained. In the research model, knowledge exploration represents the academic research and knowledge exploitation represents the university–industry collaboration. Data collected from 124 university data in online database. The study shows that knowledge exploration and exploitation both are significant positive predictors of university competitiveness. University resources play important roles to affect both knowledge exploration and exploitation in the university. The study also shows that higher knowledge exploration will enhance knowledge exploitation. Implications for theory and practice and suggestions for future research are discussed.

Anti- toxoplasma gondii activity of constituents from Balsamocitrus ...

African Journals Online (AJOL)

Isolation, characterization and anti-Toxoplasma gondii activity of constituents from the CH2Cl2/MeOH (1/1) extract of the roots of the cameroonian plant Balsamocitrus camerunensis L. were investigated in this study. Four known coumarins derivatives were isolated, namely, marmin (1), imperatorin (2), xanthoxyletin (3), ...

Cytotoxic potential of valerian constituents and valerian tinctures

NARCIS (Netherlands)

Bos, R.; Hendriks, H; Scheffer, J.J C; Woerdenbag, H.J.

Underground parts of three Valeriana species, namely V. officinalis L. s.l., V. wallichii DC. (V. jatamansi Jones), and V. edulis Nutt. ex Torr & Gray ssp. procera (H.B.K.) F. G. Meyer (V. mexicana DC.), are used in phytotherapy because of their mild sedative properties. Characteristic constituents

Constituent rearrangement model and large transverse momentum reactions

International Nuclear Information System (INIS)

Igarashi, Yuji; Imachi, Masahiro; Matsuoka, Takeo; Otsuki, Shoichiro; Sawada, Shoji.

1978-01-01

In this chapter, two models based on the constituent rearrangement picture for large p sub( t) phenomena are summarized. One is the quark-junction model, and the other is the correlating quark rearrangement model. Counting rules of the models apply to both two-body reactions and hadron productions. (author)

Determination of Chemical Constituents of the Marine Pulmonate ...

African Journals Online (AJOL)

Determination of Chemical Constituents of the Marine Pulmonate Slug, Paraoncidium reevesii. B Sun, H Shen, H Wu, L Yao, Z Cheng, Y Diao. Abstract. Purpose: To isolate and identify the chemical components of Paraoncidium reevesii. Methods: Silica gel column chromatography was used to isolate the components from ...

Surface energy budget and thermal inertia at Gale Crater: Calculations from ground-based measurements.

Science.gov (United States)

Martínez, G M; Rennó, N; Fischer, E; Borlina, C S; Hallet, B; de la Torre Juárez, M; Vasavada, A R; Ramos, M; Hamilton, V; Gomez-Elvira, J; Haberle, R M

2014-08-01

The analysis of the surface energy budget (SEB) yields insights into soil-atmosphere interactions and local climates, while the analysis of the thermal inertia ( I ) of shallow subsurfaces provides context for evaluating geological features. Mars orbital data have been used to determine thermal inertias at horizontal scales of ∼10 4  m 2 to ∼10 7  m 2 . Here we use measurements of ground temperature and atmospheric variables by Curiosity to calculate thermal inertias at Gale Crater at horizontal scales of ∼10 2  m 2 . We analyze three sols representing distinct environmental conditions and soil properties, sol 82 at Rocknest (RCK), sol 112 at Point Lake (PL), and sol 139 at Yellowknife Bay (YKB). Our results indicate that the largest thermal inertia I  = 452 J m -2  K -1  s -1/2 (SI units used throughout this article) is found at YKB followed by PL with I  = 306 and RCK with I  = 295. These values are consistent with the expected thermal inertias for the types of terrain imaged by Mastcam and with previous satellite estimations at Gale Crater. We also calculate the SEB using data from measurements by Curiosity's Rover Environmental Monitoring Station and dust opacity values derived from measurements by Mastcam. The knowledge of the SEB and thermal inertia has the potential to enhance our understanding of the climate, the geology, and the habitability of Mars.

First principles calculations on the influence of solute elements and chlorine adsorption on the anodic corrosion behavior of Mg (0001) surface

Science.gov (United States)

Luo, Zhe; Zhu, Hong; Ying, Tao; Li, Dejiang; Zeng, Xiaoqin

2018-06-01

The influences of solute atoms (Li, Al, Mn, Zn, Fe, Ni, Cu, Y, Zr) and Cl adsorption on the anodic corrosion performance on Mg (0001) surface have been investigated based on first-principles calculations, which might be useful for the design of corrosion-resistant Mg alloys. Work function and local electrode potential shift are chosen as descriptors since they quantify the barrier for charge transfer and anodic stability. We found that at 25% surface doping rate, Y decreased the work function of Mg, while the impact of remaining doping elements on the work function of Mg was trivial due to the small surface dipole moment change. The adsorption of Cl destabilized the Mg atoms at surface by weakening the bonding between surface Mg atoms. We find that a stronger hybridization of d orbits of alloying elements (e.g. Zr) with the orbits of Mg can greatly increase the local electrode potential,which even overbalances the negative effect introduced by Cl adsorbates and hence improves the corrosion resistance of Mg alloys.

IMMEDIATE CONSTITUENT ANALYSIS (IC analysis DİREKT BİLEŞENLER ANALİZİ

Directory of Open Access Journals (Sweden)

Muzaffer MALKOÇ

2011-06-01

Full Text Available IC analysis is a method of sentence analysis first explicitly introduced by American linguist Leonard Bloomfield in his book, Language, in 1933, though the underlying principle is common both to the traditional practice of parsing and to many modern systems of grammatical analysis. In IC analysis, a sentence is divided up into major divisions or immediate constituents, and these constituents are in turn divided into further immediate constituents. This process continues until irreducible constituents are reached, i.e., until each constituent consists of only a word or meaningful part of a word. The important tests used to analyze the sentences are deletion, permutation, transformation, and substitution tests.The end result of an IC analysis is often presented in a visual diagrammatic form that reveals the hierarchical immediate constituent structure of a sentence Direkt bileşenler analiz metodu Amerikalı dil bilimci Leonard Bloomfield tarafından 1933 yılında sentaks alanında başlatılmış, daha sonraki yıllarda fonetik ve morfoloji alanlarında da uygulanmıştır. Bu analiz metodunun amacı tümce veya kelime gruplarının parçalanması ve tasnif edilmesi işleminden ibarettir. Tümcelerin parçalanması en küçük dil birimine kadar kademe kademe yapılmalı ve bileşenlerin sınıflandırılmasında ise ana öbeğe veya ana gövdeye daha yakın olan unsurlar ile ikincil öğeler analizin amacına uygun olarak belirtilmelidir. Bu işlemler yapılırken Yok Etme Testi, Yer Değiştirme Testi, Dönüştürme Testi, Yerine Koyma Testi gibi metotlardan faydalanılır. Bu prensipler çerçevesinde yapılan analizin sonuçları hiyerarşik yapıları göstermek için bir grafikle özetlenir

Quantum-mechanical calculation of H on Ni(001) using a model potential based on first-principles calculations

DEFF Research Database (Denmark)

Mattsson, T.R.; Wahnström, G.; Bengtsson, L.

1997-01-01

First-principles density-functional calculations of hydrogen adsorption on the Ni (001) surface have been performed in order to get a better understanding of adsorption and diffusion of hydrogen on metal surfaces. We find good agreement with experiments for the adsorption energy, binding distance...

Acetylsalicylic acid and labeling of blood constituents with technetium-99m

Energy Technology Data Exchange (ETDEWEB)

Fonseca, Adenilson de Souza da [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Dept. de Farmacologia e Psicobiologia; Frydman, Jacques Natan Grinapel; Rocha, Vanessa Camara da; Bernardo-Filho, Mario [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Biologia Roberto Alcantara Gomes. Dept. de Biofisica e Biometria

2005-10-15

Acetylsalicylic acid is the drug most used an anti-inflammatory agent and for secondary prevention of thrombotic phenomenon. Drugs can modify the labeling of blood constituents with technetium-99m (99m Tc). The aim of this work was to evaluate the effect of in vitro or in vivo assays with acetylsalicylic acid on the labeling of the blood constituents with 99m Tc. In vitro assay was performed with samples of whole blood from Wistar rats incubated with acetylsalicylic acid (1.0 mg/ml) for one hour before the 99m Tc-labeling process. For in vivo assay, Wistar rats were treated with acetylsalicylic acid (1.5 mg/kg) during one hour, and the whole blood was withdrawn for the 99m Tc-labeling process. Saline was used in control groups. Data showed that the fixation of 99m Tc to the blood constituents was not significantly (p>0.05) modified in in vitro and in vivo assays with acetylsalicylic acid, at least not when the experiments were carried out with the doses normally used in human beings. (author)

Inhibition of nitrobenzene-induced DNA and hemoglobin adductions by dietary constituents

Energy Technology Data Exchange (ETDEWEB)

Li Hongli; Cheng Yan; Wang Haifang; Sun Hongfang; Liu Yuanfang E-mail: yliu@pku.edu.cn; Liu Kexin; Peng Shixiang

2003-03-01

Nitrobenzene (NB), a widely used industrial chemical, is a likely human carcinogen. Many dietary constituents can suppress the DNA-adduction, acting as the inhibitors of cancer. In this study, we investigated the inhibitory effects of vitamin C (VC), vitamin E (VE), tea polyphenols (TP), garlic squeeze, curcumin, and grapestone extract on NB-DNA and NB-hemoglobin (Hb) adductions in mice using an ultrasensitive method of accelerator mass spectrometry (AMS) with {sup 14}C-labelled nitrobenzene. All of these dietary constituents showed their inhibitory effects on DNA or Hb adduction. VC, VE, TP and grapestone extract could efficaciously inhibit the adductions by 33-50%, and all of these six agents could inhibit Hb adduction by 30-64%. We also investigated resveratrol, curcumin, VC and VE as inhibitors of NB-DNA adduction in vitro using liquid scintillation counting technique. These agents in the presence of NADPH and S9 components also pronouncedly blocked DNA adduction in a dose-dependent profile. Our study suggests that these seven constituents may interrupt the process of NB-induced chemical carcinogenesis.

The exact calculation of the e. m. field arising from the scattering of twodimensional electromagnetic waves at a perfectly conducting cylindrical surface of arbitrary shape

NARCIS (Netherlands)

Hoenders, B.J.

1982-01-01

The scattered field generated by the interaction of an incoming twodimensional electromagnetic wave with a cylindrical perfectly conducting surface is calculated. The scattered field is obtained in closed form.

Modeling of pollutant formation in fully premixing surface burners using a verified practice-oriented experimental reaction-kinetic calculation method. Final report

International Nuclear Information System (INIS)

Ruy, C.; Kremer, H.

1996-01-01

The intent of the present study was to simulate quantitatively pollutant formation in premixing surface burners and to describe qualitatively the share of the premixing flame in pollut emissions from atmospheric burners. For this purpose reaction-kinetic programmes for one-dimensional premixing flames were extended by a terms describing heat discharge through gas radiation. Furthermore, the calculation range for the flame was extended far into the secondary reaction zone. Temperature, CO, and NO x profiles were measured in the secondary reaction zone of premixing burners at standard pressure. The air-fuel ratio was calculated within the practically relevant range between 0.5 and 1.5, as was load behaviour. (DG) [de

Hydrogenation of ethene catalyzed by Ir atom deposited on γ-Al2O3(001) surface: From ab initio calculations

International Nuclear Information System (INIS)

Chen, Yongchang; Sun, Zhaolin; Song, Lijuan; Li, Qiang; Xu, Ming

2012-01-01

Ethene hydrogenation reaction, catalyzed by an iridium atom adsorbed on γ-Al 2 O 3 (001) surface, is studied via ab initio calculations based on density functional theory (DFT). The catalyzed reaction process and activation energy are compared with the counterparts of a reaction occurs in vacuum condition. It is found that the activation energy barrier is substantially lowered by the adsorbed Ir atom on the γ-Al 2 O 3 (001). The catalyzed reaction is modeled in two steps: (1) Hydrogen molecular dissolution and then bonded with C 2 H 4 molecular. (2) Desorption of the C 2 H 6 molecular from the surface. -- Highlights: ► The ethene hydrogenation reaction is simulated with nudged elastic band methods. ► The catalytic effect of the Ir atom on γ-Al 2 O 3 (001) surface is modeled. ► Details of the catalytic reaction are exhibited.

Method for calculating steady-state waves in an air cushion vehicle. Part 2; Air cushion vehicle no teijo zoha keisanho ni tsuite. 2

Energy Technology Data Exchange (ETDEWEB)

Eguchi, T [Mitsui Engineering and Shipbuilding Co. Ltd., Tokyo (Japan)

1997-10-01

Discussions were given on a method to estimate resistance constituents in wave resistance made in an air chamber of an air cushion vehicle (ACV). An orthogonal coordinate system is considered, which uses the center of a hull as the zero point and is made dimensionless by using cushion length. Flow around the ACV is supposed as an ideal flow, whereas speed potential is defined in the flow field. Then, a linear free surface condition is hypothesized on water surface Z = 0. Number and density of waves were used to introduce a condition to be satisfied by the speed potential. A numerical calculation method arranged a blow-out panel on the water surface, and used a panel shift type Rankine source method which satisfies the free surface condition at Z = 0. Cushion pressure distribution becomes a step-like discontinuous function, and mathematical infinity is generated in the differentiation values. Under an assumption that the pressure rises per one panel where pressure jump is present, the distribution was approximated by providing one panel with inclination of the finite quantity therein. Estimation on wave height distribution in the cushion chamber showed a tendency of qualitatively agreeing with the experimental result, but the wave heights shown in the experiment had the average level decreased as it goes toward the rear of the hull. 5 refs., 5 figs.

Calculation of a vacuum system of the installation for cleaning the surface of metal rolling by a cathode spot of a vacuum arc

Science.gov (United States)

Kuznetsov, V. G.; Kurbanov, T. A.; Kostrin, D. K.

2017-07-01

In this work are presented the installations for cleaning the surface of rolled products (wire and ribbon) from scale and technological lubricant with gateway systems of open type. The calculation of gateway devices and the optimal selection of pumping systems are shown.

Some factors in the calculation of the neutron intensity from (α,n) reactions with reference to the assay of special nuclear materials

International Nuclear Information System (INIS)

West, D.

1985-07-01

The application of neutron coincidence counting to the assay of special nuclear material involves a major correction for neutron multiplication. The correction commonly used at present requires an accurate knowledge of the intensity ratio of neutrons from (α,n) reactions to those from spontaneous fission. This paper covers various factors, which need to be evaluated in order to assess their importance, in the calculation of (α,n) neutron production using measured thick target yields. They include: accuracy of (α,n) thick target yield measurements; errors introduced by deriving yields in compounds from the measured yields in the constituents and vice-versa; the likely effect of neglecting the difference of α-particle stopping power between Pu and U on the calculated neutron yield from mixed oxide fuel pellets; the intensity of neutrons produced from 1 to 2% of Al used to alloy plutonium metal; the intensity of neutrons produced in Al, used as canning material, from α-particles escaping from the surface layers of oxide or metal fuel; and neutron production from oxygen in the air spaces of powdered PuO 2 prior to sintering. (author)

Studies on the chemical constituents, antioxidants and membrane ...

African Journals Online (AJOL)

The chemical constituents, antioxidant and membrane stability activities of Hibiscus rosa sinensis Linn. (Malvaceae) flower were determined. The total anthocyanin was 165 mg / kg with about 6 % reduction due to fermentation. Tannin, ascorbic acid, and total polyphenol were 11.8 g / kg; 478 mg / kg; and 14.4 mg / g, ...

Constituent Aspects of Workplace Guidance in Secondary VET

Science.gov (United States)

Swager, Robert; Klarus, Ruud; van Merriënboer, Jeroen J. G.; Nieuwenhuis, Loek F. M.

2015-01-01

Purpose: This paper aims to present an integrated model of workplace guidance to enhance awareness of what constitutes good guidance, to improve workplace guidance practices in vocational education and training. Design/methodology/approach: To identify constituent aspects of workplace guidance, a systematic search of Web of Science was conducted,…

Elemental constituent of food and the daily intake

International Nuclear Information System (INIS)

Suzuki, Kazumasa

1976-01-01

Constituent of element in foods and it's daily intake was discussed. In tables were shown instances of analysed values of major elements in Japanese foods, daily dietary intake of 8 elements in Japan (analysed value of total diet and estimated amounts of daily dietary intake of 32 elements. (J.P.N.)

Environmental constraints shaping constituent order in emerging communication systems: Structural iconicity, interactive alignment and conventionalization.

Science.gov (United States)

Christensen, Peer; Fusaroli, Riccardo; Tylén, Kristian

2016-01-01

Where does linguistic structure come from? Recent gesture elicitation studies have indicated that constituent order (corresponding to for instance subject-verb-object, or SVO in English) may be heavily influenced by human cognitive biases constraining gesture production and transmission. Here we explore the alternative hypothesis that syntactic patterns are motivated by multiple environmental and social-interactional constraints that are external to the cognitive domain. In three experiments, we systematically investigate different motivations for structure in the gestural communication of simple transitive events. The first experiment indicates that, if participants communicate about different types of events, manipulation events (e.g. someone throwing a cake) and construction events (e.g. someone baking a cake), they spontaneously and systematically produce different constituent orders, SOV and SVO respectively, thus following the principle of structural iconicity. The second experiment shows that participants' choice of constituent order is also reliably influenced by social-interactional forces of interactive alignment, that is, the tendency to re-use an interlocutor's previous choice of constituent order, thus potentially overriding affordances for iconicity. Lastly, the third experiment finds that the relative frequency distribution of referent event types motivates the stabilization and conventionalization of a single constituent order for the communication of different types of events. Together, our results demonstrate that constituent order in emerging gestural communication systems is shaped and stabilized in response to multiple external environmental and social factors: structural iconicity, interactive alignment and distributional frequency. Copyright © 2015 Elsevier B.V. All rights reserved.

Preventive and Prophylactic Mechanisms of Action of Pomegranate Bioactive Constituents

Science.gov (United States)

Viladomiu, Monica; Hontecillas, Raquel; Lu, Pinyi; Bassaganya-Riera, Josep

2013-01-01

Pomegranate fruit presents strong anti-inflammatory, antioxidant, antiobesity, and antitumoral properties, thus leading to an increased popularity as a functional food and nutraceutical source since ancient times. It can be divided into three parts: seeds, peel, and juice, all of which seem to have medicinal benefits. Several studies investigate its bioactive components as a means to associate them with a specific beneficial effect and develop future products and therapeutic applications. Many beneficial effects are related to the presence of ellagic acid, ellagitannins (including punicalagins), punicic acid and other fatty acids, flavonoids, anthocyanidins, anthocyanins, estrogenic flavonols, and flavones, which seem to be its most therapeutically beneficial components. However, the synergistic action of the pomegranate constituents appears to be superior when compared to individual constituents. Promising results have been obtained for the treatment of certain diseases including obesity, insulin resistance, intestinal inflammation, and cancer. Although moderate consumption of pomegranate does not result in adverse effects, future studies are needed to assess safety and potential interactions with drugs that may alter the bioavailability of bioactive constituents of pomegranate as well as drugs. The aim of this review is to summarize the health effects and mechanisms of action of pomegranate extracts in chronic inflammatory diseases. PMID:23737845

Fine structure characterization of martensite/austenite constituent in low-carbon low-alloy steel by transmission electron forward scatter diffraction.

Science.gov (United States)

Li, C W; Han, L Z; Luo, X M; Liu, Q D; Gu, J F

2016-11-01

Transmission electron forward scatter diffraction and other characterization techniques were used to investigate the fine structure and the variant relationship of the martensite/austenite (M/A) constituent of the granular bainite in low-carbon low-alloy steel. The results demonstrated that the M/A constituents were distributed in clusters throughout the bainitic ferrite. Lath martensite was the main component of the M/A constituent, where the relationship between the martensite variants was consistent with the Nishiyama-Wassermann orientation relationship and only three variants were found in the M/A constituent, suggesting that the variants had formed in the M/A constituent according to a specific mechanism. Furthermore, the Σ3 boundaries in the M/A constituent were much longer than their counterparts in the bainitic ferrite region. The results indicate that transmission electron forward scatter diffraction is an effective method of crystallographic analysis for nanolaths in M/A constituents. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

PM2.5 constituents and hospital emergency-room visits in Shanghai, China.

Science.gov (United States)

Qiao, Liping; Cai, Jing; Wang, Hongli; Wang, Weibing; Zhou, Min; Lou, Shengrong; Chen, Renjie; Dai, Haixia; Chen, Changhong; Kan, Haidong

2014-09-02

Although ambient PM2.5 has been linked to adverse health effects, the chemical constituents that cause harm are largely unclear. Few prior studies in a developing country have reported the health impacts of PM2.5 constituents. In this study, we examined the short-term association between PM2.5 constituents and emergency room visits in Shanghai, China. We measured daily concentrations of PM2.5, organic carbon (OC), elemental carbon (EC), and eight water-soluble ions between January 1, 2011 and December 31, 2012. We analyzed the data using overdispersed generalized linear Poisson models. During our study period, the mean daily average concentration of PM2.5 in Shanghai was 55 μg/m(3). Major contributors to PM2.5 mass included OC, EC, sulfate, nitrate, and ammonium. For a 1-day lag, an interquartile range increment in PM2.5 mass (36.47 μg/m(3)) corresponded to 0.57% [95% confidence interval (CI): 0.13%, 1.01%] increase of emergency room visits. In all the three models used, we found significant positive associations of emergency room visits with OC and EC. Our findings suggest that PM2.5 constituents from the combustion of fossil fuel (e.g., OC and EC) may have an appreciable influence on the health impact attributable to PM2.5.

Constituent quarks and the gluonic contribution to the spin of the nucleon

International Nuclear Information System (INIS)

Eldahoumi, Gamal

2009-01-01

The internal structure of the nucleon is more complicated than expected in a simple quark model. In particular, the portion of the nucleon spin carried by the spins of the quarks is not, as expected, of the order of one, but according to the experimental data much smaller. In this thesis we study the spin structure of the proton in quantum chromodynamics. The constituent quark model, based on SU(6), predicts that the spin of the proton should be carried by the quarks, in disagreement with the experiments. It appears strange, that the theoretical model works so well for the magnetic moments of the nucleons, but not for the spin, although the spin and the magnetic moments are closely related to each other. We shall resolve this problem by assuming that the constituent quarks have an internal structure on their own. Thus a constituent quark has a dynamical structure, and we can introduce notions like the quark or gluon distributions inside a constituent quark. In the light of new experimental data from HERMES, COMPASS, JLab, and RHIC-spin, the current status of our knowledge of the spin structure is discussed in the two theoretical frameworks: the naive parton model, and the QCD evolved parton model. QCD a is successful theory, both in perturbative and non-perturbative regions, but the spin of the nucleon still needs to be explained within QCD. (orig.)

Constituent quarks and the gluonic contribution to the spin of the nucleon

Energy Technology Data Exchange (ETDEWEB)

Eldahoumi, Gamal

2009-01-15

The internal structure of the nucleon is more complicated than expected in a simple quark model. In particular, the portion of the nucleon spin carried by the spins of the quarks is not, as expected, of the order of one, but according to the experimental data much smaller. In this thesis we study the spin structure of the proton in quantum chromodynamics. The constituent quark model, based on SU(6), predicts that the spin of the proton should be carried by the quarks, in disagreement with the experiments. It appears strange, that the theoretical model works so well for the magnetic moments of the nucleons, but not for the spin, although the spin and the magnetic moments are closely related to each other. We shall resolve this problem by assuming that the constituent quarks have an internal structure on their own. Thus a constituent quark has a dynamical structure, and we can introduce notions like the quark or gluon distributions inside a constituent quark. In the light of new experimental data from HERMES, COMPASS, JLab, and RHIC-spin, the current status of our knowledge of the spin structure is discussed in the two theoretical frameworks: the naive parton model, and the QCD evolved parton model. QCD a is successful theory, both in perturbative and non-perturbative regions, but the spin of the nucleon still needs to be explained within QCD. (orig.)

Comparison of the release of constituents from granular materials under batch and column testing.

Science.gov (United States)

Lopez Meza, Sarynna; Garrabrants, Andrew C; van der Sloot, Hans; Kosson, David S

2008-01-01

Column leaching testing can be considered a better basis for assessing field impact data than any other available batch test method and thus provides a fundamental basis from which to estimate constituent release under a variety of field conditions. However, column testing is time-intensive compared to the more simplified batch testing, and may not always be a viable option when making decisions for material reuse. Batch tests are used most frequently as a simple tool for compliance or quality control reasons. Therefore, it is important to compare the release that occurs under batch and column testing, and establish conservative interpretation protocols for extrapolation from batch data when column data are not available. Five different materials (concrete, construction debris, aluminum recycling residue, coal fly ash and bottom ash) were evaluated via batch and column testing, including different column flow regimes (continuously saturated and intermittent unsaturated flow). Constituent release data from batch and column tests were compared. Results showed no significant difference between the column flow regimes when constituent release data from batch and column tests were compared. In most cases batch and column testing agreed when presented in the form of cumulative release. For arsenic in carbonated materials, however, batch testing underestimates the column constituent release for most LS ratios and also on a cumulative basis. For cases when As is a constituent of concern, column testing may be required.

The UK Smoke Constituents Testing Study. Summary of Results and Comparison with Other Studies

Directory of Open Access Journals (Sweden)

Gregg E

2014-12-01

Full Text Available At the request of the UK Department of Health, samples of 25 commercial UK cigarette brands were provided to LGC Ltd a for smoke analysis. The brands reflected a high market share (58% in July 2001 and included a wide range of blend and product styles manufactured and imported into the UK.= 0.76, suggesting a minor role of other design features on constituents yield variability. This was confirmed by the application of multiple regression analysis to the data. A subset of five brands, retested at another laboratory, gave between-laboratory differences in mean constituent yields of as much as 2.5-fold. Consideration of these results, other likely sources of analytical variation in this study and a review of other studies, clearly indicates that any tolerance values to be associated with individual smoke constituent measurements will be greater than those for NFDPM, and in some cases, much greater. Consistent with the reported results from other large studies it is concluded that, under ISO smoking conditions, smoke constituent yields are largely predictable, if NFDPM and CO yields are known, for a standard cigarette. Given these observations and the likely limitations of analytical determination, the need for routine measurement of smoke constituent yields, other than NFDPM, nicotine or CO, on standard cigarettes, is questionable.

Do quarks play an explicit role as nuclear constituents ?

International Nuclear Information System (INIS)

Yamazaki, Toshimitsu.

1986-10-01

Experimental signatures for explicit roles of quarks as nuclear constituents are looked for. It is stressed that hyperons in nuclei may reveal unique information on nuclear interior and possible quark deconfinement. Future directions of hypernuclear spectroscopy are discussed. (author)

The chemical constituents of calabash ( Crescentia cujete ) | Ejelonu ...

African Journals Online (AJOL)

Virtually, all parts of the calabash (Crescentia cujete) tree have been found to be useful; the wood for tool handles, ribs in boat building, cattle yokes, and the gourd is used for cups, containers and musical instruments. The calabash (C. cujete) fruit was studied for its chemical constituents- proximate and mineral composition ...

Antimicrobial activity of Arctium lappa constituents against microorganisms commonly found in endodontic infections.

Science.gov (United States)

Pereira, Juliana Vianna; Bergamo, Débora Cristina Baldoqui; Pereira, José Odair; França, Suzelei de Castro; Pietro, Rosemeire Cristina Linhares Rodrigues; Silva-Sousa, Yara T Corrêa

2005-01-01

This study evaluated in vitro the antimicrobial activity of rough extracts from leaves of Arctium lappa and their phases. The following microorganisms, commonly found in the oral cavity, specifically in endodontic infections, were used: Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis and Candida albicans. The agar-diffusion method allowed detection of the hexanic phase as an inhibitor of microbial growth. Bioautographic assays identified antimicrobial substances in the extract. The results showed the existence, in the rough hexanic phase and in its fractions, of constituents that have retention factors (Rf) in three distinct zones, thereby suggesting the presence of active constituents with chemical structures of different polarities that exhibited specificity against the target microorganisms. It may be concluded that the Arctium lappa constituents exhibited a great microbial inhibition potential against the tested endodontic pathogens.

Characterization of the Lateral Distribution of Fluorescent Lipid in Binary-Constituent Lipid Monolayers by Principal Component Analysis

Directory of Open Access Journals (Sweden)

István P. Sugár

2010-01-01

Full Text Available Lipid lateral organization in binary-constituent monolayers consisting of fluorescent and nonfluorescent lipids has been investigated by acquiring multiple emission spectra during measurement of each force-area isotherm. The emission spectra reflect BODIPY-labeled lipid surface concentration and lateral mixing with different nonfluorescent lipid species. Using principal component analysis (PCA each spectrum could be approximated as the linear combination of only two principal vectors. One point on a plane could be associated with each spectrum, where the coordinates of the point are the coefficients of the linear combination. Points belonging to the same lipid constituents and experimental conditions form a curve on the plane, where each point belongs to a different mole fraction. The location and shape of the curve reflects the lateral organization of the fluorescent lipid mixed with a specific nonfluorescent lipid. The method provides massive data compression that preserves and emphasizes key information pertaining to lipid distribution in different lipid monolayer phases. Collectively, the capacity of PCA for handling large spectral data sets, the nanoscale resolution afforded by the fluorescence signal, and the inherent versatility of monolayers for characterization of lipid lateral interactions enable significantly enhanced resolution of lipid lateral organizational changes induced by different lipid compositions.

Thermal control surfaces on the MSFC LDEF experiments

International Nuclear Information System (INIS)

Wilkes, D.R.; Whitaker, A.F.; Zwiener, J.M.; Linton, R.C.; Shular, D.; Peters, P.N.; Gregory, J.C.

1992-01-01

There were five Marshall Space Flight Center (MSFC) experiments on the LDEF. Each of those experiments carried thermal control surfaces either as test samples or as operational surfaces. These materials experienced varying degrees of mechanical and optical damage. Some materials were virtually unchanged by the extended exposure while others suffered extensive degradation. The synergistic effects due to the constituents of the space environment are evident in the diversity of these material changes. The sample complement for the MSFC experiments is described along with results of the continuing analyses efforts

Tabanone a new phytotoxic constituent of cogongrass (Imperta culindrica)

Science.gov (United States)

Cogongrass [Imperata cylindrica (L.) Beauv.] is a troublesome invasive weedy species with reported allelopathic properties. The phytotoxicity of different constituents isolated from roots and aerial parts of this species was evaluated on Lactuca sativa and Agrostis stolonifera. No significant phytot...

An evaluation of calculation procedures affecting the constituent factors of equivalent circulating density for drilling hydraulics

Energy Technology Data Exchange (ETDEWEB)

Bailey, William J.

1996-12-31

This Dr. ing. thesis covers a study of drilling hydraulics offshore. The purpose of drilling hydraulics is to provide information about downhole pressure, suitable surface pump rates, the quality of hole cleaning and optimum tripping speeds during drilling operations. Main fields covered are drilling hydraulics, fluid characterisation, pressure losses, and equivalent circulating density. 197 refs., 23 figs., 22 tabs.

An evaluation of calculation procedures affecting the constituent factors of equivalent circulating density for drilling hydraulics

Energy Technology Data Exchange (ETDEWEB)

Bailey, William J

1997-12-31

This Dr. ing. thesis covers a study of drilling hydraulics offshore. The purpose of drilling hydraulics is to provide information about downhole pressure, suitable surface pump rates, the quality of hole cleaning and optimum tripping speeds during drilling operations. Main fields covered are drilling hydraulics, fluid characterisation, pressure losses, and equivalent circulating density. 197 refs., 23 figs., 22 tabs.

SU-F-T-371: Development of a Linac Monte Carlo Model to Calculate Surface Dose

Energy Technology Data Exchange (ETDEWEB)

Prajapati, S; Yan, Y; Gifford, K [UT MD Anderson Cancer Center, Houston, TX (United States)

2016-06-15

Purpose: To generate and validate a linac Monte Carlo (MC) model for surface dose prediction. Methods: BEAMnrc V4-2.4.0 was used to model 6 and 18 MV photon beams for a commercially available linac. DOSXYZnrc V4-2.4.0 calculated 3D dose distributions in water. Percent depth dose (PDD) and beam profiles were extracted for comparison to measured data. Surface dose and at depths in the buildup region was measured with radiochromic film at 100 cm SSD for 4 × 4 cm{sup 2} and 10 × 10 cm{sup 2} collimator settings for open and MLC collimated fields. For the 6 MV beam, films were placed at depths ranging from 0.015 cm to 2 cm and for 18 MV, 0.015 cm to 3.5 cm in Solid Water™. Films were calibrated for both photon energies at their respective dmax. PDDs and profiles were extracted from the film and compared to the MC data. The MC model was adjusted to match measured PDD and profiles. Results: For the 6 MV beam, the mean error(ME) in PDD between film and MC for open fields was 1.9%, whereas it was 2.4% for MLC. For the 18 MV beam, the ME in PDD for open fields was 2% and was 3.5% for MLC. For the 6 MV beam, the average root mean square(RMS) deviation for the central 80% of the beam profile for open fields was 1.5%, whereas it was 1.6% for MLC. For the 18 MV beam, the maximum RMS for open fields was 3%, and was 3.1% for MLC. Conclusion: The MC model of a linac agreed to within 4% of film measurements for depths ranging from the surface to dmax. Therefore, the MC linac model can predict surface dose for clinical applications. Future work will focus on adjusting the linac MC model to reduce RMS error and improve accuracy.

Formation of the prebiotic molecule NH2CHO on astronomical amorphous solid water surfaces: accurate tunneling rate calculations.

Science.gov (United States)

Song, Lei; Kästner, Johannes

2016-10-26

Investigating how formamide forms in the interstellar medium is a hot topic in astrochemistry, which can contribute to our understanding of the origin of life on Earth. We have constructed a QM/MM model to simulate the hydrogenation of isocyanic acid on amorphous solid water surfaces to form formamide. The binding energy of HNCO on the ASW surface varies significantly between different binding sites, we found values between ∼0 and 100 kJ mol -1 . The barrier for the hydrogenation reaction is almost independent of the binding energy, though. We calculated tunneling rate constants of H + HNCO → NH 2 CO at temperatures down to 103 K combining QM/MM with instanton theory. Tunneling dominates the reaction at such low temperatures. The tunneling reaction is hardly accelerated by the amorphous solid water surface compared to the gas phase for this system, even though the activation energy of the surface reaction is lower than the one of the gas-phase reaction. Both the height and width of the barrier affect the tunneling rate in practice. Strong kinetic isotope effects were observed by comparing to rate constants of D + HNCO → NHDCO. At 103 K we found a KIE of 231 on the surface and 146 in the gas phase. Furthermore, we investigated the gas-phase reaction NH 2 + H 2 CO → NH 2 CHO + H and found it unlikely to occur at cryogenic temperatures. The data of our tunneling rate constants are expected to significantly influence astrochemical models.

Temperature Calculations in the Coastal Modeling System

Science.gov (United States)

2017-04-01

ERDC/CHL CHETN-IV-110 April 2017 Approved for public release; distribution is unlimited . Temperature Calculations in the Coastal Modeling...tide) and river discharge at model boundaries, wave radiation stress, and wind forcing over a model computational domain. Physical processes calculated...calculated in the CMS using the following meteorological parameters: solar radiation, cloud cover, air temperature, wind speed, and surface water temperature

The Ag-Al-Cu system Part I: Reassessment of the constituent binaries on the basis of new experimental data

International Nuclear Information System (INIS)

Witusiewicz, V.T.; Hecht, U.; Fries, S.G.; Rex, S.

2004-01-01

Aiming to obtain a reliable description of the ternary Ag-Al-Cu system the thermodynamic evaluation of the constituent binaries Ag-Al, Ag-Cu and Al-Cu are revised by modelling of the Gibbs energy of all individual phases using the CALPHAD approach. The model parameters have been evaluated using a computer optimisation technique based on the established descriptions of the systems and taking into account the data on thermodynamic properties and phase equilibria both reported in recent publications and obtained by own measurements. The phase diagrams and the thermodynamic properties calculated with the evaluated parameters are in good agreement with the corresponding experimental data

Effects of fine particulate matter and its constituents on low birth weight among full-term infants in California

Energy Technology Data Exchange (ETDEWEB)

Basu, Rupa, E-mail: Rupa.Basu@oehha.ca.gov [California Office of Environmental Health Hazard Assessment, Air Pollution Epidemiology Section, Oakland, CA (United States); Harris, Maria [School of Public Health, Boston University, Boston, MA (United States); Sie, Lillian [School of Public Health, University of California, Berkeley, CA (United States); Malig, Brian; Broadwin, Rachel; Green, Rochelle [California Office of Environmental Health Hazard Assessment, Air Pollution Epidemiology Section, Oakland, CA (United States)

2014-01-15

Relationships between prenatal exposure to fine particles (PM{sub 2.5}) and birth weight have been observed previously. Few studies have investigated specific constituents of PM{sub 2.5}, which may identify sources and major contributors of risk. We examined the effects of trimester and full gestational prenatal exposures to PM{sub 2.5} mass and 23 PM{sub 2.5} constituents on birth weight among 646,296 term births in California between 2000 and 2006. We used linear and logistic regression models to assess associations between exposures and birth weight and risk of low birth weight (LBW; <2500 g), respectively. Models were adjusted for individual demographic characteristics, apparent temperature, month and year of birth, region, and socioeconomic indicators. Higher full gestational exposures to PM{sub 2.5} mass and several PM{sub 2.5} constituents were significantly associated with reductions in term birth weight. The largest reductions in birth weight were associated with exposure to vanadium, sulfur, sulfate, iron, elemental carbon, titanium, manganese, bromine, ammonium, zinc, and copper. Several of these PM{sub 2.5} constituents were associated with increased risk of term LBW. Reductions in birth weight were generally larger among younger mothers and varied by race/ethnicity. Exposure to specific constituents of PM{sub 2.5}, especially traffic-related particles, sulfur constituents, and metals, were associated with decreased birth weight in California. -- Highlights: • Examine full gestational and trimester fine particle and its constituents on term birth weight. • Fine particles and several of its constituents associated with birth weight reductions. • Largest reductions for traffic-related particles, sulfur constituents, and metals. • Greater birth weight reductions for younger mothers, and varied by race/ethnicity.

Assessment of selected inorganic constituents in streams in the Central Arizona Basins Study Area, Arizona and northern Mexico, through 1998

Science.gov (United States)

Anning, David W.

2003-01-01

Stream properties and water-chemistry constituent concentrations from data collected by the National Water-Quality Assessment and other U.S. Geological Survey water-quality programs were analyzed to (1) assess water quality, (2) determine natural and human factors affecting water quality, and (3) compute stream loads for the surface-water resources in the Central Arizona Basins study area. Stream temperature, pH, dissolved-oxygen concentration and percent saturation, and dissolved-solids, suspended-sediment, and nutrient concentration data collected at 41 stream-water quality monitoring stations through water year 1998 were used in this assessment. Water-quality standards applicable to the stream properties and water-chemistry constituent concentration data for the stations investigated in this study generally were met, although there were some exceedences. In a few samples from the White River, the Black River, and the Salt River below Stewart Mountain Dam, the pH in reaches designated as a domestic drinking water source was higher than the State of Arizona standard. More than half of the samples from the Salt River below Stewart Mountain Dam and almost all of the samples from the stations on the Central Arizona Project Canal?two of the three most important surface-water sources used for drinking water in the Central Arizona Basins study area?exceeded the U.S. Environmental Protection Agency drinking water Secondary Maximum Contaminant Level for dissolved solids. Two reach-specific standards for nutrients established by the State of Arizona were exceeded many times: (1) the annual mean concentration of total phosphorus was exceeded during several years at stations on the main stems of the Salt and Verde Rivers, and (2) the annual mean concentration of total nitrogen was exceeded during several years at the Salt River near Roosevelt and at the Salt River below Stewart Mountain Dam. Stream properties and water-chemistry constituent concentrations were related to

[n-Butyl Alcohol-soluble Chemical Constituents of Psidium guajava Leaves].

Science.gov (United States)

Chen, Gang; Wan, Kai-hua; Fu, Hui-zheng; Yan, Qing-wei

2015-03-01

To study the chemical constituents of the leaves of Psidium guajava. The chemical constituents were isolated by column chromatography on silica gel, Sephadex LH-20 and MPLC. Their chemical structures were elucidated on the basis of special analysis. Seven compounds were isolated from n-butyl alcohol fraction, whose structures were elucidated as morin-3-O-α-L-arabopyranoside (1), morin-3-O-α-L-iyxopyranoside (2), 2,6-dihydroxy-4-O-β-D-glucopyranosyl-benzophenone (3), casuarictin (4),2,6-dihydroxy-3,5-dimethyl-4-O-(6"-O-galloyl-β-D-glucopyranosyl)-benzophenone(5), globulusin A(6), and kaempferol-3-O-β-D-(6"-galloyl) galactopyranoside (7). Compounds 3 and 5 ~ 7 are isolated from this plant for the first time.

From fundamental fields to constituent quarks and nucleon form factors?

International Nuclear Information System (INIS)

Coester, F.

1991-01-01

Constituent-quark models formulated in the frame work of nonrelativistic quantum mechanics have been successful in accounting for the mass spectra of mesons and baryons. Applications to elastic electron scattering require relativistic dynamics. Relativistic quantum mechanics of constituent quarks can be formulated by constructing a suitable unitary representation of the Poincare group on the three-quark Hilbert space. The mass and spin operators of this representation specify the relativistic model dynamics. The dynamics of fundamental quark fields, on the other hand, is specified by a Euclidean functional integral. In this paper, the author shows how the dynamics of the fundamental fields can be related in principle to the Hamiltonian dynamics of quark particles through the properties of the Wightman functions

Salacia crassifolia (Celastraceae: CHEMICAL CONSTITUENTS AND ANTIMICROBIAL ACTIVITY

Directory of Open Access Journals (Sweden)

Vanessa G. Rodrigues

2015-02-01

Full Text Available The phytochemical study of hexane extract from leaves of Salacia crassifolia resulted in the isolation of 3β-palmitoxy-urs-12-ene, 3-oxofriedelane, 3β-hydroxyfriedelane, 3-oxo-28-hydroxyfriedelane, 3-oxo-29-hydroxyfriedelane, 28,29-dihydroxyfriedelan-3-one, 3,4-seco-friedelan-3-oic acid, 3β-hydroxy-olean-9(11:12-diene and the mixture of α-amirin and β-amirin. β-sitosterol, the polymer gutta-percha, squalene and eicosanoic acid were also isolated. The chemical structures of these constituents were established by IR, 1H and 13C NMR spectral data. Crude extracts and the triterpenes were tested against Entamoeba histolytica, Giardia lamblia and Trichomonas vaginalis and no activity was observed under the in vitro assay conditions. The hexane, chloroform, ethyl acetate and ethanol crude extracts, and the constituent 3,4-seco-friedelan-3-oic acid and 28,29-dihydroxyfriedelan-3-one showed in vitro antimicrobial activity against Salmonella typhimurium, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Streptococcus sanguinis and Candida albicans.

Inferring CO2 Fluxes from OCO-2 for Assimilation into Land Surface Models to Calculate Net Ecosystem Exchange

Science.gov (United States)

Prouty, R.; Radov, A.; Halem, M.; Nearing, G. S.

2016-12-01

Investigations of mid to high latitude atmospheric CO2 show a growing seasonal amplitude. Land surface models poorly predict net ecosystem exchange (NEE) and are unable to substantiate these sporadic observations. An investigation of how the biosphere has reacted to changes in atmospheric CO2 is essential to our understanding of potential climate-vegetation feedbacks. A global, seasonal investigation of CO2-flux is then necessary in order to assimilate into land surface models for improving the prediction of annual NEE. The Atmospheric Radiation Measurement program (ARM) of DOE collects CO2-flux measurements (in addition to CO2 concentration and various other meteorological quantities) at several towers located around the globe at half hour temporal frequencies. CO2-fluxes are calculated via the eddy covariance technique, which utilizes CO2-densities and wind velocities to calculate CO2-fluxes. The global coverage of CO2 concentrations as provided by the Orbiting Carbon Observatory (OCO-2) provide satellite-derived CO2 concentrations all over the globe. A framework relating the satellite-inferred CO2 concentrations collocated with the ground-based ARM as well as Ameriflux stations would enable calculations of CO2-fluxes far from the station sites around the entire globe. Regression techniques utilizing deep-learning neural networks may provide such a framework. Additionally, meteorological reanalysis allows for the replacement of the ARM multivariable meteorological variables needed to infer the CO2-fluxes. We present the results of inferring CO2-fluxes from OCO-2 CO2 concentrations for a two year period, Sept. 2014- Sept. 2016 at the ARM station located near Oklahoma City. A feed-forward neural network (FFNN) is used to infer relationships between the following data sets: F([ARM CO2-density], [ARM Meteorological Data]) = [ARM CO2-Flux] F([OCO-2 CO2-density],[ARM Meteorological Data]) = [ARM CO2-Flux] F([ARM CO2-density],[Meteorological Reanalysis]) = [ARM CO2-Flux

Infinite slab-shield dose calculations

International Nuclear Information System (INIS)

Russell, G.J.

1989-01-01

I calculated neutron and gamma-ray equivalent doses leaking through a variety of infinite (laminate) slab-shields. In the shield computations, I used, as the incident neutron spectrum, the leakage spectrum (<20 MeV) calculated for the LANSCE tungsten production target at 90 degree to the target axis. The shield thickness was fixed at 60 cm. The results of the shield calculations show a minimum in the total leakage equivalent dose if the shield is 40-45 cm of iron followed by 20-15 cm of borated (5% B) polyethylene. High-performance shields can be attained by using multiple laminations. The calculated dose at the shield surface is very dependent on shield material. 4 refs., 4 figs., 1 tab

Single-neuron identification of chemical constituents, physiological changes, and metabolism using mass spectrometry.

Science.gov (United States)

Zhu, Hongying; Zou, Guichang; Wang, Ning; Zhuang, Meihui; Xiong, Wei; Huang, Guangming

2017-03-07

The use of single-cell assays has emerged as a cutting-edge technique during the past decade. Although single-cell mass spectrometry (MS) has recently achieved remarkable results, deep biological insights have not yet been obtained, probably because of various technical issues, including the unavoidable use of matrices, the inability to maintain cell viability, low throughput because of sample pretreatment, and the lack of recordings of cell physiological activities from the same cell. In this study, we describe a patch clamp/MS-based platform that enables the sensitive, rapid, and in situ chemical profiling of single living neurons. This approach integrates modified patch clamp technique and modified MS measurements to directly collect and detect nanoliter-scale samples from the cytoplasm of single neurons in mice brain slices. Abundant possible cytoplasmic constituents were detected in a single neuron at a relatively fast rate, and over 50 metabolites were identified in this study. The advantages of direct, rapid, and in situ sampling and analysis enabled us to measure the biological activities of the cytoplasmic constituents in a single neuron, including comparing neuron types by cytoplasmic chemical constituents; observing changes in constituent concentrations as the physiological conditions, such as age, vary; and identifying the metabolic pathways of small molecules.

New methodology for analytical calculation of resonance integrals in an heterogeneous medium

International Nuclear Information System (INIS)

Campos, T.P.R. de; Martinez, A.S.

1986-01-01

A new methodology for analytical calculation of Resonance Integral in a typical fuel cell is presented. The expression obtained for the Resonance Integral presents the advantage of being analytical. Its constituent terms are combinations of the well known function J(xi,β) with its partial derivatives in regard to β. This is a general expression for all types of resonance. The parameters used in this method depend on the resonance type and are obtained as a function of the parameter lambda. A simple expression, depending on resonance parameters is proposed for this variable. (Author) [pt

Communication: A new ab initio potential energy surface for HCl-H2O, diffusion Monte Carlo calculations of D0 and a delocalized zero-point wavefunction.

Science.gov (United States)

Mancini, John S; Bowman, Joel M

2013-03-28

We report a global, full-dimensional, ab initio potential energy surface describing the HCl-H2O dimer. The potential is constructed from a permutationally invariant fit, using Morse-like variables, to over 44,000 CCSD(T)-F12b∕aug-cc-pVTZ energies. The surface describes the complex and dissociated monomers with a total RMS fitting error of 24 cm(-1). The normal modes of the minima, low-energy saddle point and separated monomers, the double minimum isomerization pathway and electronic dissociation energy are accurately described by the surface. Rigorous quantum mechanical diffusion Monte Carlo (DMC) calculations are performed to determine the zero-point energy and wavefunction of the complex and the separated fragments. The calculated zero-point energies together with a De value calculated from CCSD(T) with a complete basis set extrapolation gives a D0 value of 1348 ± 3 cm(-1), in good agreement with the recent experimentally reported value of 1334 ± 10 cm(-1) [B. E. Casterline, A. K. Mollner, L. C. Ch'ng, and H. Reisler, J. Phys. Chem. A 114, 9774 (2010)]. Examination of the DMC wavefunction allows for confident characterization of the zero-point geometry to be dominant at the C(2v) double-well saddle point and not the C(s) global minimum. Additional support for the delocalized zero-point geometry is given by numerical solutions to the 1D Schrödinger equation along the imaginary-frequency out-of-plane bending mode, where the zero-point energy is calculated to be 52 cm(-1) above the isomerization barrier. The D0 of the fully deuterated isotopologue is calculated to be 1476 ± 3 cm(-1), which we hope will stand as a benchmark for future experimental work.

SU-E-T-196: Comparative Analysis of Surface Dose Measurements Using MOSFET Detector and Dose Predicted by Eclipse - AAA with Varying Dose Calculation Grid Size

Energy Technology Data Exchange (ETDEWEB)

Badkul, R; Nejaiman, S; Pokhrel, D; Jiang, H; Kumar, P [University of Kansas Medical Center, Kansas City, KS (United States)

2015-06-15

Purpose: Skin dose can be the limiting factor and fairly common reason to interrupt the treatment, especially for treating head-and-neck with Intensity-modulated-radiation-therapy(IMRT) or Volumetrically-modulated - arc-therapy (VMAT) and breast with tangentially-directed-beams. Aim of this study was to investigate accuracy of near-surface dose predicted by Eclipse treatment-planning-system (TPS) using Anisotropic-Analytic Algorithm (AAA)with varying calculation grid-size and comparing with metal-oxide-semiconductor-field-effect-transistors(MOSFETs)measurements for a range of clinical-conditions (open-field,dynamic-wedge, physical-wedge, IMRT,VMAT). Methods: QUASAR™-Body-Phantom was used in this study with oval curved-surfaces to mimic breast, chest wall and head-and-neck sites.A CT-scan was obtained with five radio-opaque markers(ROM) placed on the surface of phantom to mimic the range of incident angles for measurements and dose prediction using 2mm slice thickness.At each ROM, small structure(1mmx2mm) were contoured to obtain mean-doses from TPS.Calculations were performed for open-field,dynamic-wedge,physical-wedge,IMRT and VMAT using Varian-21EX,6&15MV photons using twogrid-sizes:2.5mm and 1mm.Calibration checks were performed to ensure that MOSFETs response were within ±5%.Surface-doses were measured at five locations and compared with TPS calculations. Results: For 6MV: 2.5mm grid-size,mean calculated doses(MCD)were higher by 10%(±7.6),10%(±7.6),20%(±8.5),40%(±7.5),30%(±6.9) and for 1mm grid-size MCD were higher by 0%(±5.7),0%(±4.2),0%(±5.5),1.2%(±5.0),1.1% (±7.8) for open-field,dynamic-wedge,physical-wedge,IMRT,VMAT respectively.For 15MV: 2.5mm grid-size,MCD were higher by 30%(±14.6),30%(±14.6),30%(±14.0),40%(±11.0),30%(±3.5)and for 1mm grid-size MCD were higher by 10% (±10.6), 10%(±9.8),10%(±8.0),30%(±7.8),10%(±3.8) for open-field, dynamic-wedge, physical-wedge, IMRT, VMAT respectively.For 6MV, 86% and 56% of all measured values

The use of bulk states to accelerate the band edge state calculation of a semiconductor quantum dot

International Nuclear Information System (INIS)

Voemel, Christof; Tomov, Stanimire Z.; Wang, Lin-Wang; Marques, Osni A.; Dongarra, Jack J.

2007-01-01

We present a new technique to accelerate the convergence of the folded spectrum method in empirical pseudopotential band edge state calculations for colloidal quantum dots. We use bulk band states of the materials constituent of the quantum dot to construct initial vectors and a preconditioner. We apply these to accelerate the convergence of the folded spectrum method for the interior states at the top of the valence and the bottom of the conduction band. For large CdSe quantum dots, the number of iteration steps until convergence decreases by about a factor of 4 compared to previous calculations

Study on adsorption of O2 on LaFe1−xMgxO3 (0 1 0) surface by density function theory calculation

International Nuclear Information System (INIS)

Liu, Xing; Cheng, Bin; Hu, Jifan; Qin, Hongwei

2012-01-01

Highlights: ► Mg-doping can change the electronic properties of LaFeO 3 (0 1 0) surface by decreasing the band gap. ► The position and content of Mg-doping can both affect the ability to adsorb O 2 . ► The strong hybridization between O 2 p and Fe d orbital is the origin of binding mechanism. - Abstract: The adsorption of O 2 on the clean and Mg doped LaFeO 3 (0 1 0) surface has been investigated using the density functional theory (DFT) method. Calculation results show that Mg-doping can change the electronic properties of LaFeO 3 (0 1 0) surface by decreasing the band gap. When Mg ions were not on the first layer of the surface, with increasing Mg content the adsorption of O 2 was enhanced. When Mg ions were on the first layer, the adsorption of O 2 was weakened with the increase of Mg content. The analysis results of the DOS indicated that the Mg ion and adsorbed O 2 had no strong hybridization, and the bonding mechanism was originated from the strong hybridization between the O p and Fe d orbital. Referring to all the calculation results, it was found that except for the increase of stability of oxygen adsorption, the Mg doping could not improve the sensitivity to O 2 .

Exploring basic biochemical constituents in the body tissues of ...

African Journals Online (AJOL)

Feeding regime did not influence susceptibility to mass loss during export. Animal age influenced the biochemical composition and export performance of abalone. Keywords: abalone; aquaculture; feeds; Haliotis midae; live export; mass loss; tissue biochemical constituents. African Journal of Marine Science 2010, 32(1): ...

Isolation of nematicidal constituents from essential oil of Kaempferia ...

African Journals Online (AJOL)

Purpose: To explore the nematicidal activities of the essential oil of Kaempferia galanga rhizomes and its isolated constituents against Heterodera avenae. Methods: Essential oil of K. galanga rhizomes was obtained by hydrodistillation and characterized by gas chromatography/mass spectrometric (GC/MS) analysis using ...

Volatilization behavior of transactinides from metal surfaces and melts (thermochemical calculation); Verfluechtigungsverhalten der Transaktinoide von Metalloberflaechen und aus Schmelzen (Thermochemische Kalkulation)

Energy Technology Data Exchange (ETDEWEB)

Eichler, B

2003-01-01

Volatilization properties of elements with the atomic numbers Z=104 to 116 are determined on the basis of empirical relations. These empirical correlations are deduced from the analysis of thermochemical data of metallic elements in the periodic table and their relations to the material constant: Structure specific connections are shown to exist between the electron densities at the 'Wigner-Seitz' cell borders of metals and the specific surface energies of solid metals with hexagonal, cubic face-centred, cubic body-centred and rhombohedral lattices. Analogously, structure specific relations can be found between the standard enthalpies of the gaseous monoatomic metals and their surface energies. Linear correlations with exceptionally high correlation coefficients are observed between the standard sublimation enthalpies of isotypic metals in the dimeric state and the surface energies. Volatilization properties are deduced for the transactinides on the basis of these established relations, applying a predicted structure and further empirical correlations. These volatilization properties are in detail: the standard enthalpies of the gaseous monomers; the standard sublimation enthalpies of the dimers; the standard dissociation enthalpies of the dimers; the standard enthalpies of adsorption on metal surfaces; the volatilization enthalpies from molten metals, and the standard formation enthalpies of hetero binuclear intermetallic molecules. Thermochemical constants required for the calculation of the intermetallic interactions are determined using the Miedema model. The closed systematic approach facilitate: the assessment of the calculated data considering the agreement with known rules of metal chemistry, trends in the 7{sup t}h row and along the groups of the periodic table, the coherence of the data, and the action of closed shell effects in the electron configurations. From the obtained data conclusions are possible regarding the design of volatilization

A novel method of calculating the energy deposition curve of nanosecond pulsed surface dielectric barrier discharge

International Nuclear Information System (INIS)

He, Kun; Wang, Xinying; Lu, Jiayu; Cui, Quansheng; Pang, Lei; Di, Dongxu; Zhang, Qiaogen

2015-01-01

To obtain the energy deposition curve is very important in the fields to which nanosecond pulse dielectric barrier discharges (NPDBDs) are applied. It helps the understanding of the discharge physics and fast gas heating. In this paper, an equivalent circuit model, composed of three capacitances, is introduced and a method of calculating the energy deposition curve is proposed for a nanosecond pulse surface dielectric barrier discharge (NPSDBD) plasma actuator. The capacitance C d and the energy deposition curve E R are determined by mathematically proving that the mapping from C d to E R is bijective and numerically searching one C d that satisfies the requirement for E R to be a monotonically non-decreasing function. It is found that the value of capacitance C d varies with the amplitude of applied pulse voltage due to the change of discharge area and is dependent on the polarity of applied voltage. The bijectiveness of the mapping from C d to E R in nanosecond pulse volumetric dielectric barrier discharge (NPVDBD) is demonstrated and the feasibility of the application of the new method to NPVDBD is validated. This preliminarily shows a high possibility of developing a unified approach to calculate the energy deposition curve in NPDBD. (paper)

Characterization of hazardous constituents in HLW supernate and implications for solid LLW generation