WorldWideScience
1

MOLECULAR-LEVEL PROCESS GOVERNING THE INTERACTION OF CONTAMINANTS WITH IRON AND MANGANESE OXIDES  

Science.gov (United States)

Many of the inorganic and organic contaminants present in sediments at DOE sites can be altered or destroyed by reduction and oxidation (redox) reactions occurring at mineral surfaces. A fundamental understanding of such redox processes provided by molecular-level studies on stru...

2

Molecular-Level Processes Governing the Interaction of Contaminants with Iron and Manganese Oxides - Final Report  

Energy Technology Data Exchange (ETDEWEB)

Many of the inorganic and organic contaminants present in sediments at DOE sites can be altered or destroyed by reduction and oxidation (redox) reactions occurring at mineral surfaces. A fundamental understanding of such redox processes provided by molecular-level studies on structurally and compositionally well-defined mineral surfaces will lead to: (i) improved models of contaminant fate and transport in geochemical systems, and (ii) optimized manipulation of these processes for remediation purposes. To contribute to this understanding, we will study, both experimentally and theoretically, redox processes involving three important contaminants - chromate ion, carbon tetrachloride, and trichloroethene TCE, on the following iron and manganese oxides - hematite, magnetite, maghemite, and pyrolusite. These oxides and their hydroxylated analogs commonly occur as coatings on minerals or as interfaces in the subsurface environment. Single-crystal surfaces of these oxides will be synthesized in carefully controlled fashion by molecular beam epitaxy. These surfaces, as well as high surface are powdered samples of these oxides, will be used in spectroscopic and kinetic experiments in both aqueous and gas phases. Our goal is to identify products and to determine the kinetics and mechanisms of surface-catalyzed redox reaction of Cr(VI) and CR(III), and the reductive dechlorination of carbon tetrachloride and TCE. The combination of theory and experiment will provide the base information needed to scale from the molecular level to the microscopic grain level minerals.

Brown Jr., G. E.; Chambers, S. A.

1999-10-31

3

Molecular Processes Studied at a Single-Molecule Level Using DNA Origami Nanostructures and Atomic Force Microscopy  

OpenAIRE

DNA origami nanostructures allow for the arrangement of different functionalities such as proteins, specific DNA structures, nanoparticles, and various chemical modifications with unprecedented precision. The arranged functional entities can be visualized by atomic force microscopy (AFM) which enables the study of molecular processes at a single-molecular level. Examples comprise the investigation of chemical reactions, electron-induced bond breaking, enzymatic binding and cleavage events, an...

Ilko Bald; Adrian Keller

2014-01-01

4

Direct molecular-level Monte Carlo simulation of Joule-Thomson processes  

Science.gov (United States)

We present an application of the recently developed constant enthalpy-constant pressure Monte Carlo method [Smith, W. R., and Lísal, M., 2002, Phys. Rev. E, 66, 01114] for the direct simulation of Joule-Thomson expansion processes using a molecular-level system model. For the alternative refrigerant HFC-32 (CH2F2), we perform direct simulations of the isenthalpic integral Joule-Thomson effect (temperature drop) resulting from Joule-Thomson expansion from an initial pressure to the representative final pressure of 1 bar. We consider representative expansions from single-phase states yielding final states in both single-phase and two-phase regions. We also predict the dependence of T(P,h) and of the Joule-Thomson coefficient, ?(P,h), on pressure along several representative isenthalps, as well as points on the Joule-Thomson inversion curve. HFC-32 is modelled using a five-site potential taken from the literature, with parameters derived from ab initio calculations and vapour-liquid equilibrium data. The simulated results show excellent agreement with those calculated from an international standard equation of state.

Lísal, Martin; Smith, William R.; Aim, Karel

5

Molecular Processes Studied at a Single-Molecule Level Using DNA Origami Nanostructures and Atomic Force Microscopy  

Directory of Open Access Journals (Sweden)

Full Text Available DNA origami nanostructures allow for the arrangement of different functionalities such as proteins, specific DNA structures, nanoparticles, and various chemical modifications with unprecedented precision. The arranged functional entities can be visualized by atomic force microscopy (AFM which enables the study of molecular processes at a single-molecular level. Examples comprise the investigation of chemical reactions, electron-induced bond breaking, enzymatic binding and cleavage events, and conformational transitions in DNA. In this paper, we provide an overview of the advances achieved in the field of single-molecule investigations by applying atomic force microscopy to functionalized DNA origami substrates.

Ilko Bald

2014-09-01

6

Insights into surface–adsorbate interactions in corrosion inhibition processes at the molecular level  

International Nuclear Information System (INIS)

Graphical abstract: The interaction of 2-((3-methylpyridine-2-imino)methyl)phenol (MPIMP) with the Fe(1 1 0) surface was clarified at the molecular level using density functional theory (DFT). Highlights: •2-((3-Methylpyridine-2-imino)methyl)phenol was tested as a corrosion inhibitor. •Its interaction with the surface was characterized using density functional theory. •Three stable adsorption configurations on Fe(1 1 0) surface were identified. -- Abstract: 2-((3-Methylpyridine-2-imino)methyl)phenol (MPIMP) was investigated as a potential corrosion inhibitor for mild steel in 0.5 M HCl solution using impedance spectroscopy (IS). Changes in impedance parameters indicated that adsorption of MPIMP occurred on the mild steel surface. Three stable adsorption configurations for MPIMP on the Fe(1 1 0) surface were identified as a result of geometry optimization starting from several adsorption geometries using density functional theory (DFT). Involvement of the delocalized ?-electrons of the aromatic rings in the interaction provides extra stabilization to the flat adsorption configurations

7

Excited states structure and processes: Understanding organic light-emitting diodes at the molecular level  

Science.gov (United States)

Photo- or electro-excited states in polyatomic molecules, aggregates, and conjugated polymers are at the center of organic light-emitting diodes (OLEDs). These can decay radiatively or non-radiatively, determining the luminescence quantum efficiency of molecular materials. According to Kasha’s rule, light-emission is dictated by the lowest-lying excited state. For conjugated polymers, the electron correlation effect can lead the lowest-lying excited state to the even-parity 2Ag state which is non-emissive. To understand the nature of the low-lying excited state structure, we developed the density matrix renormalization group (DMRG) theory and its symmetrization scheme for quantum chemistry applied to calculate the excited states structure. We found there are three types of 1Bu/2Ag crossover behaviors: with electron correlation strength U, with bond length alternation, and with conjugation length. These directly influence the light-emitting property. For the electro-excitation, carriers (electron and hole) are injected independently, forming both singlet and triplet excited bound states with statistically 25% and 75% portions, respectively. We found that the exciton formation rate can depend on spin manifold, and for conjugated polymers, the singlet exciton can have larger formation rate leading to the internal electroluminescence quantum efficiency larger than the 25% spin statistical limit. It is originated from the interchain electron correlation as well as intrachain lattice relaxation. For the dipole allowed emissive state, the radiative decay process via either spontaneous emission or stimulated emission can be computed from electronic structure plus vibronic couplings. The challenging issue lies in the non-radiative decay via non-adiabatic coupling and/or spin-orbit coupling. We developed a unified correlation function formalism for the excited state radiative and non-radiative decay rates. We emphasized the low-frequency mode mixing (Duschinsky rotation) effect on the non-radiative decay. We further combined the non-adiabatic coupling and spin-orbit coupling for the triplet state decay (phosphorescence) quantum efficiency. All the formalisms have been developed analytically, which have been applied to optical spectroscopy, aggregation-induced emission phenomena, and polymer photovoltaic property.

Shuai, Zhigang; Peng, Qian

2014-04-01

8

Identification of light absorbing oligomers from glyoxal and methylglyoxal aqueous processing: a comparative study at the molecular level  

Science.gov (United States)

Numerous studies point to the reactive uptake of gaseous low molecular weight carbonyls onto atmospheric waters (clouds/fog droplets and wet aerosols) as an important SOA formation route not yet included in current models. However, the evaluation of these processes is challenging because water provides a medium for a complex array of reactions to take place such as self-oligomerization, aldol condensation and Maillard-type browning reactions in the presence of ammonium salts. In addition to adding to SOA mass, aqueous chemistry products have been shown to include light absorbing, surface-active and high molecular weight oligomeric species, and can therefore affect climatically relevant aerosol properties such as light absorption and hygroscopicity. Glyoxal (GLY) and methylglyoxal (MGLY) are the gaseous carbonyls that have perhaps received the most attention to date owing to their ubiquity, abundance and reactivity in water, with the majority of studies focussing on bulk physical properties. However, very little is known at the molecular level, in particular for MGLY, and the relative potential of these species as aqueous SOA precursors in ambient air is still unclear. We have conducted experiments with both laboratory solutions and chamber-generated particles to simulate the aqueous processing of GLY and MGLY with ammonium sulphate (AS) under typical atmospheric conditions and investigated their respective aging products. Both high performance liquid chromatography coupled with UV-Vis detection and ion trap mass spectrometry (HPLC-DAD-MSn) and high resolution mass spectrometry (FTICRMS) have been used for molecular identification purposes. Comprehensive gas chromatography with nitrogen chemiluminescence detection (GCxGC-NCD) has been applied for the first time to these systems, revealing a surprisingly high number of nitrogen-containing organics (ONs), with a large extent of polarities. GCxGC-NCD proved to be a valuable tool to determine overall amount and rates of formation of the light absorbing species. Data obtained from laboratory solutions were merged with those from SOA generated in chamber experiments conducted at the European PhotoReactor (EUPHORE) from the uptake of gas-phase GLY and MGLY onto AS seeds. While in general the results confirm previous studies in ranking MGLY as more effective than GLY in brown carbon formation, the link between overall optical properties and the identified molecular species is reported here for the first time for both systems.

Finessi, Emanuela; Hamilton, Jacqueline; Rickard, Andrew; Baeza-Romero, Maria; Healy, Robert; Peppe, Salvatore; Adams, Tom; Daniels, Mark; Ball, Stephen; Goodall, Iain; Monks, Paul; Borras, Esther; Munoz, Amalia

2014-05-01

9

Photodissociation processes in molecular beams  

Energy Technology Data Exchange (ETDEWEB)

A description is presented of a study of the photodissociation dynamics of molecules in a molecular beam. Photo-fragmentation translational spectroscopy has been utilized to observe the photodissociation dynamics of ozone. Using a supersonic molecular beam and a 10 nanosecond pulsed laser at lambda = 266 nm, the velocities of the fragment products are measured by the method of time of flight. The resolution of the time of flight spectrum of ozone is sufficiently high that the electronic and vibrational states are clearly resolved and identified. Above the threshold (lambda < 310 nm), the quantum yield for the production of O(/sup 1/D) has been estimated in the past to be unity for the process O/sub 3/ (/sup 1/A/sub 1/) + h..nu..)lambda < 300 nm) ..-->.. O/sub 3/(/sup 1/B/sub 2/) ..-->.. O/sub 2/(/sup 1/..delta../sub g/) + O(/sup 1/D). However a small production of O/sub 2/ (/sup 3/..sigma../sub g//sup -/) + O(/sup 3/P) has been observed in this study. The O/sub 2/(/sup 1/..delta../sub g/) product yields four vibrational states (v = 0, 1, 2, 3) which yields a vibrational temperature of 2700/sup 0/K along with narrow energy distributions of rotational levels. These energy distributions are compared with photodissociation models along with the polarization dependence of the dissociative process which was also measured. 143 references.

Carlson, L.R.

1979-05-01

10

Photodissociation processes in molecular beams  

International Nuclear Information System (INIS)

A description is presented of a study of the photodissociation dynamics of molecules in a molecular beam. Photo-fragmentation translational spectroscopy has been utilized to observe the photodissociation dynamics of ozone. Using a supersonic molecular beam and a 10 nanosecond pulsed laser at lambda = 266 nm, the velocities of the fragment products are measured by the method of time of flight. The resolution of the time of flight spectrum of ozone is sufficiently high that the electronic and vibrational states are clearly resolved and identified. Above the threshold (lambda 1D) has been estimated in the past to be unity for the process O3 (1A1) + h?)lambda 3(1B2) ? O2(1?/sub g/) + O(1D). However a small production of O2 (3?/sub g/-) + O(3P) has been observed in this study. The O2(1?/sub g/) product yields four vibrational states (v = 0, 1, 2, 3) which yields a vibrational temperature of 27000K along with narrow energy distributions of rotational levels. These energy distributions are compared with photodissociation models along with the polarization dependence of the dissociative process which was also measured. 143 references

11

Imaging gene expression and endogenous molecular processes: molecular imaging.  

Science.gov (United States)

Noninvasive molecular imaging has developed over the past decade and involves nuclear (positron emission tomography [PET], gamma camera), magnetic resonance, and optical imaging systems. Most current molecular imaging strategies are "indirect" and involve the coupling of a "reporter gene" with a complementary "reporter probe." Imaging the level of probe accumulation provides indirect information related to the level of reporter gene expression. Reporter gene constructs are driven by upstream promoter/enhancer elements; reporter gene expression can be leading to continuous transcription and used to identify the site of transduction and to monitor the level and duration of gene (vector) activity. Alternatively, reporter gene expression can be leading to controlled gene expression, or reporter genes can function as a "sensor" to monitor the level of endogenous promoters and transcription factors. The development of versatile and sensitive assays that do require tissue sampling will be of considerable value for monitoring molecular-genetic and cellular processes in animal models of human disease, as well as for studies in human subjects in the future. Noninvasive imaging of molecular-genetic and cellular processes will complement established molecular-biologic assays that require tissue sampling, and will provide a spatial as well as a temporal dimension to our understanding of various diseases. Several examples of imaging endogenous biologic processes in animals using reporter constructs, radiolabeled probes, and PET imaging are reviewed (e.g., p53-dependent gene expression, T-cell receptor-dependent activation of T-lymphocytes, and preliminary studies of endogenous HIF-1alpha expression). Issues related to the translation of noninvasive molecular imaging technology into the clinic are also discussed. PMID:12368652

Blasberg, Ronald

2002-10-01

12

Observation of molecular level behavior in molecular electronic junction device  

Science.gov (United States)

In this dissertation, I utilize AFM based scanning probe measurement and surface enhanced Raman scattering based vibrational spectroscopic analysis to directly characterize topographic, electronic, and chemical properties of molecules confined in the local area of M3 junction to elucidate the molecular level behavior of molecular junction electronic devices. In the introduction, the characterization of molecular electronic devices with different types of metal-molecule-metal (M3) structures based upon self-assembled monolayers (SAMs) is reviewed. A background of the characterization methods I use in this dissertation, conducting probe atomic force microscopy (cp-AFM) and surface enhanced Raman spectroscopy (SERS), is provided in chapter 1. Several attempts are performed to create the ideal top metal contacts on SAMs by metal vapor phase deposition in order to prevent the metal penetration inducing critical defects of the molecular electronic devices. The scanning probe microscopy (SPM), such as cp-AFM, contact mode (c-) AFM and non-contact mode (nc-) AFM, in ultra high vacuum conditions are utilized to study the process of the metal-SAM interface construction in terms of the correlation between the morphological and electrical properties including the metal nucleation and filament generation as a function of the functionalization of long-chain alkane thiolate SAMs on Au. In chapter 2, the nascent condensation process of vapor phase Al deposition on inert and reactive SAMs are studied by SPM. The results of top deposition, penetration, and filament generation of deposited Al are discussed and compared to the results previously observed by spectroscopic measurements. Cp-AFM was shown to provide new insights into Al filament formation which has not been observed by conventional spectroscopic analysis. Additionally, the electronic characteristics of individual Al filaments are measured. Chapter 3 reveals SPM characterization of Au deposition onto --COOH terminated SAMs utilized with strong surface dipole-dipole intermolecular interaction based on hydrogen bonding and ionic bonding potentially preventing the metal penetration. The observed results are discussed with kinetic paths of metal atoms on each SAM including temporal vacancies controlled by the intermolecular interactions in SAM upon the comparison with the spectroscopic results previously reported. The results in chapter 2 and 3 strongly suggests that AFM based characterization technique is powerful tool especially for detecting molecular-size local phenomena in vapor phase metal deposition process, especially, the electric short-circuit filaments growing through SAMs, which may induce critical misinterpretation of M3 junction device properties. In Chapter 4, an altered metal deposition process on inert SAM with using a buffer layer is performed to diminish the kinetic energy of impinging metal atoms. SPM characterization reveals an abrupt metal-SAM interface without any metal penetration. Examined electric characteristics also revealed typical non-resonant tunneling characteristics of long chain alkane thiolate SAMs. In chapter 5, the buffer layer assisted growth process is used to prepare a nano particles-SAM pristine interface on SAMs to control the metal-SAM interaction in order to study the fundamental issue of chemical enhancement mechanism of SERS. Identical Au nanoparticles-SAM-Au M3 structures with different Au-SAM interactions reveal a large discrepancy of enhancement factors of ˜100 attributed to the chemical interaction. In chapter 6, Raman spectroscopy of M3 junction is applied to the characterization of molecular electronics devices. A crossed nanowire junction (X-nWJ) device is employed for in-situ electronic-spectroscopic simultaneous characterization using Raman spectroscopy. A detailed study reveals the multi-probe capability of X-nWJ for in-situ Raman and in-elastic electron tunneling spectroscopy (IETS) as vibrational spectroscopies to diagnose molecular electronic devices. In chapter 7, aniline oligomer (OAn) based redox SAMs are characterized b

Maitani, Masato

13

Atomic and molecular collision processes  

International Nuclear Information System (INIS)

530Accomplishments during the course of a 44-month program of code development and high precision calculations for electron collisions with atoms, atomic ions, and molecules are summarized. In electron-atom and -ion collisions, we were primarily concerned with the fundamental physics of the process that controls excitation in high temperature plasmas. In the molecular work, we pursued the development of techniques for accurate calculations of ro-vibrational excitation of polyatomic molecules, to the modeling of gas-phase laser systems. Highlights from the seven technical paper published as a result of this contract include: The resolution of a long history of unexplained anomalies and experimental/theoretical discrepancies by a demonstration that the Coulomb phase must be included in scattering amplitudes for electron-ion collisions. Definitive close-coupling calculations of cross sections for electron impact excitation of Be+, using a very elaborate expansion for the collision system and inclusion of both one- and two-body terms for the effect of core polarization. Detailed state-of-the-art calculations for electron-impact excitation of the sodium-like ion A ell 2+ that included core-polarization interactions, and which also produced new data on bound-state energy levels for the magnesium-like ion A ell + and oscillator strengths for A ell 2+. Partial cross sections for excitation of the 3p level of sodium at energies just above threshold calculated using a four-state close-coupling approach, including both total cross sections and those for excitation as a function of the change in the spin and orbital angular momentum projection quantum numbers of the target electron. Generalization of our electron-molecule scattering code to carry out full vibrational close-coupling calculations with an exact treatment of exchange and with a parameter-free representation of correlation and polarization interactions, and application to HF and H2

14

Energy conversion at the molecular level  

International Nuclear Information System (INIS)

This paper describes the fundamental principles that play an important role in the design of devices for optical excitation-charge splitting at the molecular level. Specific cases are chosen as illustrations. Work based on metal to ligand charge transfer (MLCT) excited states is included

15

Processing TES Level-2 Data  

Science.gov (United States)

TES Level 2 Subsystem is a set of computer programs that performs functions complementary to those of the program summarized in the immediately preceding article. TES Level-2 data pertain to retrieved species (or temperature) profiles, and errors thereof. Geolocation, quality, and other data (e.g., surface characteristics for nadir observations) are also included. The subsystem processes gridded meteorological information and extracts parameters that can be interpolated to the appropriate latitude, longitude, and pressure level based on the date and time. Radiances are simulated using the aforementioned meteorological information for initial guesses, and spectroscopic-parameter tables are generated. At each step of the retrieval, a nonlinear-least-squares- solving routine is run over multiple iterations, retrieving a subset of atmospheric constituents, and error analysis is performed. Scientific TES Level-2 data products are written in a format known as Hierarchical Data Format Earth Observing System 5 (HDF-EOS 5) for public distribution.

Poosti, Sassaneh; Akopyan, Sirvard; Sakurai, Regina; Yun, Hyejung; Saha, Pranjit; Strickland, Irina; Croft, Kevin; Smith, Weldon; Hoffman, Rodney; Koffend, John; Benenyan, Gerard; Nair, Hari; Sarkissian, Edwin; McDuffie, James; Monarrez, Ruth; Ho,David; Chan, Benny; Lampel, Michael

2006-01-01

16

Dynamical processes in atomic and molecular physics  

CERN Document Server

Atomic and molecular physics underlie a basis for our knowledge of fundamental processes in nature and technology and in such applications as solid state physics, chemistry and biology. In recent years, atomic and molecular physics has undergone a revolutionary change due to great achievements in computing and experimental techniques. As a result, it has become possible to obtain information both on atomic and molecular characteristics and on dynamics of atomic and molecular processes. This e-book highlights the present state of investigations in the field of atomic and molecular physics. Rece

Ogurtsov, Gennadi

2012-01-01

17

Humidity level In psychrometric processes  

International Nuclear Information System (INIS)

When a thermal engineer needs to control, rather than merely moderate humidity, he must focus on the moisture level as a separate variable - not simply an addition of temperature control. Controlling humidity generally demands a correct psychrometric approach dedicated to that purpose [1].Analysis of the humidity level in psychrometric thermal processes leads to relevant data for theory and practice [2]. This paper presents: (1) the summer climatic curve for the Skopje region, (2) selected results of investigation on farm dryers made outside laboratories. The first purpose of such activity was to examine relations between weather conditions and drying conditions. The estimation of weather condition for the warmest season of the year was realized by a summer climatic curve. In the science of drying, basic drying conditions are temperature, relative humidity and velocity of air, thickness of dried product and dryer construction. The second purpose was to realize correct prediction of drying rates for various psychrometrics drying processes and local products. Test runs with the dryer were carried out over a period of 24 h, using fruits and vegetables as experimental material. Air flow rate through the dryer of 150 m3/h, overall drying rate of 0.04 kg/h and air temperature of 65 oC were reached. Three types of solar dryers, were exploited in the research.

18

Atomic and molecular processes in fusion plasmas  

Energy Technology Data Exchange (ETDEWEB)

The role of atomic and molecular processes in achieving and maintaining the conditions for thermonuclear burn in a magnetically confined fusion plasma is described. Emphasis is given to the energy balance and power and particle exhaust issues. The most important atomic and molecular processes which affect the radiation losses and impurity transport in the core plasma, the neutral particle transport in the plasma edge and the radiative cooling of divertor plasmas are discussed in greater detail. (author)

Janev, R.K. [International Atomic Energy Agency, Vienna (Austria)

1997-01-01

19

The auditory corticocollicular system: molecular and circuit-level considerations.  

Science.gov (United States)

We live in a world imbued with a rich mixture of complex sounds. Successful acoustic communication requires the ability to extract meaning from those sounds, even when degraded. One strategy used by the auditory system is to harness high-level contextual cues to modulate the perception of incoming sounds. An ideal substrate for this process is the massive set of top-down projections emanating from virtually every level of the auditory system. In this review, we provide a molecular and circuit-level description of one of the largest of these pathways: the auditory corticocollicular pathway. While its functional role remains to be fully elucidated, activation of this projection system can rapidly and profoundly change the tuning of neurons in the inferior colliculus. Several specific issues are reviewed. First, we describe the complex heterogeneous anatomical organization of the corticocollicular pathway, with particular emphasis on the topography of the pathway. We also review the laminar origin of the corticocollicular projection and discuss known physiological and morphological differences between subsets of corticocollicular cells. Finally, we discuss recent findings about the molecular micro-organization of the inferior colliculus and how it interfaces with corticocollicular termination patterns. Given the assortment of molecular tools now available to the investigator, it is hoped that his review will help guide future research on the role of this pathway in normal hearing. PMID:24911237

Stebbings, Kevin A; Lesicko, Alexandria M H; Llano, Daniel A

2014-08-01

20

1978 bibliography of atomic and molecular processes  

International Nuclear Information System (INIS)

This annotated bibliography lists 2557 works on atomic and molecular processes reported in publications dated 1978. Sources include scientific journals, conference proceedings, and books. Each entry is designated by one or more of the 114 categories of atomic and molecular processes used by the Controlled Fusion Atomic Data Center to classify data. Also indicated is whether the work was experimental or theoretical, what energy range was covered, what reactants were investigated, and the country of origin of the first author. Following the bibliographical listing are indexes of reactants and authors

21

1979 bibliography of atomic and molecular processes  

International Nuclear Information System (INIS)

This annotated bibliography lists 2146 works on atomic and molecular processes reported in publications dated 1979. Sources include scientific journals, conference proceedings, and books. Each entry is designated by one or more of the 114 categories of atomic and molecular processes used by the Controlled Fusion Atomic Data Center, Oak Ridge National Laboratory, to classify data. Also indicated is whether the work was experimental or theoretical, what energy range was covered, what reactants were investigated, and the country of origin of the first author. Following the bibliographical listing are indexes of reactants and authors

22

1982 bibliography of atomic and molecular processes  

International Nuclear Information System (INIS)

This annotated bibliography includes papers on atomic and molecular processes published during 1982. Sources include scientific journals, conference proceedings, and books. Each entry is designated by one or more of the 114 categories of atomic and molecular processes used by the Controlled Fusion Atomic Data Center, Oak Ridge National Laboratory to classify data. Also indicated is whether the work was experimental or theoretical, what energy range was covered, what reactants were investigated, and the country of origin of the first author. Following the bibliographical listing, the entries are indexed according to the categories and according to reactants within each subcategory

23

1982 bibliography of atomic and molecular processes  

Energy Technology Data Exchange (ETDEWEB)

This annotated bibliography includes papers on atomic and molecular processes published during 1982. Sources include scientific journals, conference proceedings, and books. Each entry is designated by one or more of the 114 categories of atomic and molecular processes used by the Controlled Fusion Atomic Data Center, Oak Ridge National Laboratory to classify data. Also indicated is whether the work was experimental or theoretical, what energy range was covered, what reactants were investigated, and the country of origin of the first author. Following the bibliographical listing, the entries are indexed according to the categories and according to reactants within each subcategory.

Barnett, C.F.; Crandall, D.H.; Gilbody, H.B.; Gregory, D.C.; Kirkpatrick, M.I.; McDaniel, E.W.; McKnight, R.H.; Meyer, F.W.; Morgan, T.J.; Phaneuf, R.A. (comps.)

1984-05-01

24

1985 bibliography of atomic and molecular processes  

Energy Technology Data Exchange (ETDEWEB)

This annotated bibliography includes papers on atomic and molecular processes published during 1985. Sources include scientific journals, conference proceedings, and books. Each entry is designated by one or more of the 114 categories of atomic and molecular processes used by the Controlled Fusion Atomic Data Center, Oak Ridge National Laboratory to classify data. Also indicated is whether the work was experimental or theoretical, what energy range was covered, what reactants were investigated, and the country of origin of the first author. Following the bibliographical listing, the entries are indexed according to the categories and according to reactants within each subcategory.

Barnett, C.F.; Gilbody, H.B.; Gregory, D.C.; Griffin, P.M.; Havener, C.C.; Howald, A.M.; Kirkpatrick, M.I.; McDaniel, E.W.; Meyer, F.W.; Morgan, T.J. (comps.)

1986-06-01

25

Bibliography of atomic and molecular processes, 1983  

International Nuclear Information System (INIS)

This annotated bibliography includes papers on atomic and molecular processes published during 1983. Sources include scientific journals, conference proceedings, and books. Each entry is designated by one or more of the 114 categories of atomic and molecular processes used by the Controlled Fusion Atomic Data Center, Oak Ridge National Laboratory to classify data. Also indicated is whether the work was experimental or theoretical, what energy range was covered, what reactants were investigated, and the country of origin of the first author. Following the bibliographical listing, the entries are indexed according to the categories and according to reactants within each subcategory

26

1984 Bibliography of atomic and molecular processes  

International Nuclear Information System (INIS)

This annotated bibliography includes papers on atomic and molecular processes published during 1984. Sources include scientific journals, conference proceedings, and books. Each entry is designated by one or more of the 114 categories of atomic and molecular processes used by the Controlled Fusion Atomic Data Center, Oak Ridge National Laboratory to classify data. Also indicated is whether the work was experimental or theoretical, what energy range was covered, what reactants were investigated, and the country of origin of the first author. Following the bibliographical listing, the entries are indexed according to the categories and according to reactants within each subcategory

27

1985 bibliography of atomic and molecular processes  

International Nuclear Information System (INIS)

This annotated bibliography includes papers on atomic and molecular processes published during 1985. Sources include scientific journals, conference proceedings, and books. Each entry is designated by one or more of the 114 categories of atomic and molecular processes used by the Controlled Fusion Atomic Data Center, Oak Ridge National Laboratory to classify data. Also indicated is whether the work was experimental or theoretical, what energy range was covered, what reactants were investigated, and the country of origin of the first author. Following the bibliographical listing, the entries are indexed according to the categories and according to reactants within each subcategory

28

Bibliography of atomic and molecular processes, 1983  

Energy Technology Data Exchange (ETDEWEB)

This annotated bibliography includes papers on atomic and molecular processes published during 1983. Sources include scientific journals, conference proceedings, and books. Each entry is designated by one or more of the 114 categories of atomic and molecular processes used by the Controlled Fusion Atomic Data Center, Oak Ridge National Laboratory to classify data. Also indicated is whether the work was experimental or theoretical, what energy range was covered, what reactants were investigated, and the country of origin of the first author. Following the bibliographical listing, the entries are indexed according to the categories and according to reactants within each subcategory.

Barnett, C.F.; Crandall, D.H.; Gilbody, H.B.; Gregory, D.C.; Kirkpatrick, M.I.; McDaniel, E.W.; McKnight, R.H.; Meyer, F.W.; Morgan, T.J.; Phaneuf, R.A. (comps.)

1984-10-01

29

1980 bibliography of atomic and molecular processes  

International Nuclear Information System (INIS)

This annotated bibliography lists 2866 works on atomic and molecular processes reported in publications dated 1980. Sources include scientific journals, conference proceedings, and books. Each entry is designated by one or more of the 114 categories of atomic and molecular processes used by the Controlled Fusion Atomic Data Center, Oak Ridge National Laboratory, to classify data. Also indicated is whether the work was experimental or theoretical, what energy range was covered, what reactants were investigated, and the country of origin of the first author. Following the bibliographical listing are indexes of reactants and authors

30

1984 Bibliography of atomic and molecular processes  

Energy Technology Data Exchange (ETDEWEB)

This annotated bibliography includes papers on atomic and molecular processes published during 1984. Sources include scientific journals, conference proceedings, and books. Each entry is designated by one or more of the 114 categories of atomic and molecular processes used by the Controlled Fusion Atomic Data Center, Oak Ridge National Laboratory to classify data. Also indicated is whether the work was experimental or theoretical, what energy range was covered, what reactants were investigated, and the country of origin of the first author. Following the bibliographical listing, the entries are indexed according to the categories and according to reactants within each subcategory.

Barnett, C.F.; Gilbody, H.B.; Gregory, D.C.; Griffin, P.M.; Havener, C.C.; Howard, A.M.; Kirkpatrick, M.I.; McDaniel, E.W.; Meyer, F.W.; Morgan, T.J. (comps.)

1985-04-01

31

Molecular processes in the early Universe  

International Nuclear Information System (INIS)

Molecular processes first took place in the Universe in the recombination era as the expanding Universe cooled adiabatically and recombined when the cooling radiation field ran out of photons energetic enough to cause photoionization. The formation of neutral helium heralded the dawn of chemistry as the neutral atoms participated in processes of radiative association to form molecular ions. Dissociative recombination of the molecular ions produced neutral atoms and accelerated the conversion of the ionized plasma into a neutral gas. The subsequent chemistry involved hydrogen, deuterium, helium and lithium created earlier in a brief period of nucleosynthesis. With the continued expansion the Universe became cold and dark and chemistry came to a temporary end until the formation and gravitational collapse of the first distinct cosmological objects. Heavy elements were made, a new source of radiation - starlight - appeared and a richer chemistry was initiated

32

Systemic structural modular generalization of the crystallography of bound water applied to study the mechanisms of processes in biosystems at the atomic and molecular level  

International Nuclear Information System (INIS)

The main reasons of the modern scientific revolution, one of the consequences of which are nanotechnologies and the development of interdisciplinary overall natural science (which can build potentially possible atomic structures and study the mechanisms of the processes occurring in them), are considered. The unifying role of crystallography in the accumulation of interdisciplinary knowledge is demonstrated. This generalization of crystallography requires the introduction of a new concept: a module which reflects the universal condition for stability of all real and potential and equilibrium and nonequilibrium structures of matter (their connectivity). A modular generalization of crystallography covers all forms of solids, including the structure of bound water (a system-forming matrix for the self-organization and morphogenesis of hierarchical biosystems which determines the metric selection of all other structural components of these systems). A dynamic model of the water surface layer, which serves as a matrix in the formation of Langmuir monolayers and plays a key role in the occurrence of life on the Earth, is developed.

33

Quantum mechanics of molecular rate processes  

CERN Document Server

This survey of applications of the theory of collisions and rate processes to molecular problems explores collisions of molecules with internal structure, generalized Ehrenfest theorem, theory of reactive collisions, and role of symmetry. It also reviews partitioning technique, equivalent potentials and quasibound states, theory of direct reactions, more. 1969 edition.

Levine, Raphael D

2011-01-01

34

Molecular sieving silica membrane fabrication process  

Energy Technology Data Exchange (ETDEWEB)

A process for producing a molecular sieve silica membrane comprising depositing a hybrid organic-inorganic polymer comprising at least one organic constituent and at least one inorganic constituent on a porous substrate material and removing at least a portion of the at least one organic constituent of the hybrid organic-inorganic polymer, forming a porous film.

Raman, Narayan K. (400 Maple St. SE., Apartment 112, Albuquerque, NM 87106); Brinker, Charles Jeffrey (14 Eagle Nest Dr., NE., Albuquerque, NM 87122)

1998-01-01

35

Molecular sieving silica membrane fabrication process  

Energy Technology Data Exchange (ETDEWEB)

A process for producing a molecular sieve silica membrane comprising depositing a hybrid organic-inorganic polymer comprising at least one organic constituent and at least one inorganic constituent on a porous substrate material and removing at least a portion of the at least one organic constituent of the hybrid organic-inorganic polymer, forming a porous film.

Raman, Narayan K. (Monroeville, PA); Brinker, Charles Jeffrey (Albuquerque, NM)

1999-01-01

36

Molecular sieving silica membrane fabrication process  

Energy Technology Data Exchange (ETDEWEB)

A process is described for producing a molecular sieve silica membrane comprising depositing a hybrid organic-inorganic polymer comprising at least one organic constituent and at least one inorganic constituent on a porous substrate material and removing at least a portion of the at least one organic constituent of the hybrid organic-inorganic polymer, forming a porous film. 11 figs.

Raman, N.K.; Brinker, C.J.

1999-08-10

37

Molecular processes in cellular arsenic metabolism  

International Nuclear Information System (INIS)

Elucidating molecular processes that underlie accumulation, metabolism and binding of iAs and its methylated metabolites provides a basis for understanding the modes of action by which iAs acts as a toxin and a carcinogen. One approach to this problem is to construct a conceptual model that incorporates available information on molecular processes involved in the influx, metabolism, binding and efflux of arsenicals in cells. This conceptual model is initially conceived as a non-quantitative representation of critical molecular processes that can be used as a framework for experimental design and prediction. However, with refinement and incorporation of additional data, the conceptual model can be expressed in mathematical terms and should be useful for quantitative estimates of the kinetic and dynamic behavior of iAs and its methylated metabolites in cells. Development of a quantitative model will be facilitated by the availability of tools and techniques to manipulate molecular processes underlying transport of arsenicals across cell membranes or expression and activity of enzymes involved in methylation of arsenicals. This model of cellular metabolism might be integrated into more complex pharmacokinetic models for systemic metabolism of iAs and its methylated metabolites. It may also be useful in development of biologically based dose-response models describing the toxic and carcinogenic actions of arsenicals

38

Features, Events, and Processes: system Level  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this analysis report is to evaluate and document the inclusion or exclusion of the system-level features, events, and processes (FEPs) with respect to modeling used to support the total system performance assessment for the license application (TSPA-LA). A screening decision, either Included or Excluded, is given for each FEP along with the technical basis for screening decisions. This information is required by the U.S. Nuclear Regulatory Commission (NRC) at 10 CFR 63.113 (d, e, and f) (DIRS 156605). The system-level FEPs addressed in this report typically are overarching in nature, rather than being focused on a particular process or subsystem. As a result, they are best dealt with at the system level rather than addressed within supporting process-level or subsystem-level analyses and models reports. The system-level FEPs also tend to be directly addressed by regulations, guidance documents, or assumptions listed in the regulations; or are addressed in background information used in development of the regulations. For included FEPs, this analysis summarizes the implementation of the FEP in the TSPA-LA (i.e., how the FEP is included). For excluded FEPs, this analysis provides the technical basis for exclusion from the TSPA-LA (i.e., why the FEP is excluded). The initial version of this report (Revision 00) was developed to support the total system performance assessment for site recommendation (TSPA-SR). This revision addresses the license application (LA) FEP List (DIRS 170760).

D. McGregor

2004-10-15

39

Features, Events, and Processes: system Level  

International Nuclear Information System (INIS)

The purpose of this analysis report is to evaluate and document the inclusion or exclusion of the system-level features, events, and processes (FEPs) with respect to modeling used to support the total system performance assessment for the license application (TSPA-LA). A screening decision, either Included or Excluded, is given for each FEP along with the technical basis for screening decisions. This information is required by the U.S. Nuclear Regulatory Commission (NRC) at 10 CFR 63.113 (d, e, and f) (DIRS 156605). The system-level FEPs addressed in this report typically are overarching in nature, rather than being focused on a particular process or subsystem. As a result, they are best dealt with at the system level rather than addressed within supporting process-level or subsystem-level analyses and models reports. The system-level FEPs also tend to be directly addressed by regulations, guidance documents, or assumptions listed in the regulations; or are addressed in background information used in development of the regulations. For included FEPs, this analysis summarizes the implementation of the FEP in the TSPA-LA (i.e., how the FEP is included). For excluded FEPs, this analysis provides the technical basis for exclusion from the TSPA-LA (i.e., why the FEP is excluded). The initial version of this report (Revision 00) was developed to support the total system performance assessment for site recommendation (TSPA-SR). This revision addresses the license application (LA) FEP List (DIRS 170760)

40

Challenge of representing entropy at different levels of resolution in molecular simulation.  

Science.gov (United States)

The role of entropic contributions in processes involving biomolecules is illustrated using the process of vaporization or condensation of the solvents water and methanol and the process of polypeptide folding in solution using molecular models at different levels of resolution: subatomic, atomic, supra-atomic, and supramolecular. For the folding process, a ?-hexapeptide that adopts, as inferred from NMR experiments, both a right-handed 2.710/12-helical fold and a left-handed 314-helical fold in methanol, is used to illustrate the challenge of modeling thermodynamically driven processes at different levels of resolution. PMID:25147102

Huang, Wei; van Gunsteren, Wilfred F

2015-01-22

41

Practical ?-Ray Level for Low Molecular Weight Chitosan  

International Nuclear Information System (INIS)

The present work proposes a practical level of ?-Ray to lower the molecular weigh of chitosan irradiated in solid state and water. The molecular weight reduction is up to 80% at ?-ray amount of 50 kGy. The same level of reduction can be achieved by only 20 kGy in the presence of initiator (K2S2O8 or H2O2). The structure is significantly changed in the case of chitosan-acetic acid solution or chitosan dispersed in water with 2% aq. K2S2O8 solution

42

All-optical processing with molecular switches.  

Science.gov (United States)

A gradual transition from electrical to optical networks is accompanying the rapid progress of telecommunication technology. The urge for enhanced transmission capacity and speed is dictating this trend. In fact, large volumes of data encoded on optical signals can be transported rapidly over long distances. Their propagation along specific routes across a communication network is ensured by a combination of optical fibers and optoelectronic switches. It is becoming apparent, however, that the interplay between the routing electrical stimulations and the traveling optical signals will not be able to support the terabit-per-second capacities that will be needed in the near future. Electrical inputs cannot handle the immense parallelism potentially possible with optical signals. Operating principles to control optical signals with optical signals must be developed. Molecular and supramolecular switches are promising candidates for the realization of innovative materials for information technology. Binary digits can be encoded in their chemical, electrical, or optical inputs and outputs to execute specific logic functions. We have developed a simple strategy to gate optical signals with optical signals by using a photoactive molecular switch. We have demonstrated that NAND, NOR, and NOT operations can be implemented exclusively with optical inputs and optical outputs coupling from one to three switching elements. Our remarkably simple approach to all-optical switching might lead to the development of a new generation of devices for digital processing and communication technology. PMID:16578866

Raymo, Françisco M; Giordani, Silvia

2002-04-16

43

Green-solvent-processed molecular solar cells.  

Science.gov (United States)

High-efficiency bulk heterojunction (BHJ) organic solar cells with power conversion efficiencies of more than 5?% can be fabricated using the green solvent 2-MeTHF. The active layers comprise a blend of a molecular semiconductor donor with intermediate dimensions (X2) and the soluble fullerene derivative [6,6]-phenyl-C61 -butyricacidoctylester (PC61 BC8 ). A switch of the processing solvent from chloroform to 2-MeTHF leads to no negative impacts on the morphology and charge-transport properties of optimally performing BHJ films. Examinations by absorption spectroscopy, atomic force microscopy, and grazing incidence wide-angle X-ray scattering reveal no significant modification of morphology. These results show that green solvents can be excellent alternatives for large-area printing of high-performance organic photovoltaics (OPVs) and thus open new opportunities for sustainable mass production of organic solar cells and other optoelectronic devices. PMID:25389005

Chen, Xiaofen; Liu, Xiaofeng; Burgers, Mark A; Huang, Ye; Bazan, Guillermo C

2014-12-22

44

Towards an Upper-Level Ontology for Molecular Biology  

OpenAIRE

There is a growing need for the general-purpose description of the basic ontological entities in the life sciences domain. Up until now, upper-level models are mainly purpose-driven, such as the GENIA ontology, originally devised as a vocabulary for corpus annotation. As an alternative, we here present BioTop, a description-logic-based top-level ontology for molecular biology, as an ontologically more conscious re-design of the GENIA ontology.

Schulz, Stefan; Beisswanger, Elena; Wermter, Joachim; Hahn, Udo

2006-01-01

45

Wafer level 3-D ICs process technology  

CERN Document Server

This book focuses on foundry-based process technology that enables the fabrication of 3-D ICs. The core of the book discusses the technology platform for pre-packaging wafer lever 3-D ICs. However, this book does not include a detailed discussion of 3-D ICs design and 3-D packaging. This is an edited book based on chapters contributed by various experts in the field of wafer-level 3-D ICs process technology. They are from academia, research labs and industry.

Tan, Chuan Seng; Reif, L Rafael

2009-01-01

46

Actinides and environmental interfaces: striving for molecular-level understanding  

International Nuclear Information System (INIS)

Actinides can undergo a variety of complex chemical reactions in the environment. In addition to the formation of solid precipitates, colloids and dissolved solution species common to aqueous systems, actinide ions can interact with the surrounding geo and biomedia to change oxidation states or sorb on surfaces and colloids. The rate of migration is determined by aqueous solubility, and interactions with solid surfaces such as minerals, soils, natural organic matter, and soil microorganisms Sorption of aqueous actinide species on biological and geological matrices can be quantitatively described by a surface complexation or site-binding model. The disadvantage of this model is the difficulty in the experimental determination of the model parameters and surface reaction constants. Usually, a set of surface reactions and species are proposed based on knowledge of the solution speciation of the solute, and the reaction constants are usually derived by fitting computer-calculated absorption curves to experimental data. Because this process typically involves a large number of potentially adjustable parameters, it is likely to lead to non-unique parameter fitting and does not always result in a consistent set of parameters for the same systems. A fundamental molecular-level understanding of sorption processes of actinides on environmental surfaces is required to better understand and predict their transport behavior in nature. Several different surface spectroscopic techniral different surface spectroscopic techniques have been applied to the characterization of the adsorbed species and surface reactions and a direct determination of the sorbed species and surface reactions has become possible. The non-linear optical techniques of second harmonic and sum frequency generation (SHG and SFG) are ideally suited to study surfaces and interfaces of mineral oxides, biosurfactants and biopolymers, organic adlayers adsorbed on solid/mineral surfaces and soil organic matter, including humic and fulvic acids. Resonant enhanced second harmonic generation can probe the electronic (UV-vis region) structure of metal species adsorbed at a surface or interface. Infrared-visible sum frequency generation spectroscopy probes the infrared vibrational spectrum of molecules adsorbed at the interface. SHG/SFG studies will greatly assist with understanding reactivity at interfaces of oxides and soil organic matter with heavy metals and radionuclides/actinides. Time-resolved Laser-fluorescence spectroscopy (TRLFS) is a highly sensitive tool for actinides that absorb light and de-excite by fluorescence emission, e.g., U(VI) and Cm(III), to probe changes in actinide speciation and coordination environment in solution. This method can also be used to differentiate whether adsorbed species form surface complexes or surface precipitates. Recently, it was shown that the intense synchrotron radiation can change the oxidation states of redox-sensitive actinide samples which may cause erroneous results, and low temperature measurements are now used to alleviate this shortcoming. X-ray Absorption Fine Structure (XAFS) Spectroscopy is composed of two component spectroscopies, X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) which provide element specific oxidation state and local structure information, respectively. EXAFS (Extended X-ray Absorption Fine Structure Spectroscopy) provides information on the chemical environment of particular actinide, in particular bond lengths and the number of neighboring atoms. Combining both methods, detailed knowledge of the different processes resulting from the interaction of the selected actinides with environmental interfaces can be gained. XANES and EXAFS measurements and TRLFS studies to obtain molecular-level mechanistic details of actinide interaction with common environmental solutions and interfaces will be presented together with first SHG/SFG characterization results of model systems for environmental interfaces. Areas will be outlined where integrated interdisciplin

47

Molecular Simulation of Fundamental Processes in Nanoparticle - Polymer - Nanoparticle Systems Under Tensile Load  

Directory of Open Access Journals (Sweden)

Full Text Available We demonstrate molecular modeling of polymer (polyacrylate association to ZnO nanoparticles by means of a recently developed molecule-by-molecule association approach. Upon multiple acrylate association steps, potential sites for connecting ZnO particles are elaborated and explored under tensile loading from molecular dynamics simulation. This offers molecular level insights into processes that account for elastic and plastic deformation, creep and self-healing in ZnO-polymer composite materials

Dirk Zahn

2013-08-01

48

Monitoring process mean level using auxiliary information  

OpenAIRE

In this study, a Shewhart-type control chart is proposed for the improved monitoring of process mean level (targeting both moderate and large shifts which is the major concern of Shewhart-type control charts) of a quality characteristic of interest Y. The proposed control chart, namely the M-r chart, is based on the regression estimator of mean using a single auxiliary variable X. Assuming bivariate normality of (Y, X), the design structure of M-r chart is developed for phase I quality contro...

Riaz, M.

2008-01-01

49

Rovibronic energy levels for triplet electronic states of molecular deuterium  

OpenAIRE

An optimal set of 1050 rovibronic energy levels for 35 triplet electronic states of $D_2$ has been obtained by means of a statistical analysis of all available wavenumbers of triplet-triplet rovibronic transitions studied in emission, absorption, laser and anticrossing spectroscopic experiments of various authors. We used a new method of the analysis (Lavrov, Ryazanov, JETP Letters, 2005), which does not need any \\it a priori \\rm assumptions concerning the molecular structur...

Lavrov, B. P.; Umrikhin, I. S.

2007-01-01

50

Molecular basis of lactase levels in adult humans.  

OpenAIRE

The molecular basis of adult human "lactase deficiency" has long been a subject of controversy. To address this issue, small intestinal biopsies from orienta, black, and white patients were analyzed. Adjacent samples were assayed for lactase and sucrase specific activities and the sucrase/lactase ratio (high ratio signifies lactase deficiency), and the results were compared to lactase steady-state mRNA levels detected in Northern blots probed with a human lactase mDNA. All oriental patients h...

Escher, J. C.; Koning, N. D.; Engen, C. G.; Arora, S.; Bu?ller, H. A.; Montgomery, R. K.; Grand, R. J.

1992-01-01

51

Renewal processes and fluctuation analysis of molecular motor stepping  

CERN Document Server

We model the dynamics of a processive or rotary molecular motor using a renewal processes, in line with the work initiated by Svoboda, Mitra and Block. We apply a functional technique to compute different types of multiple-time correlation functions of the renewal process, which have applications to bead-assay experiments performed both with processive molecular motors, such as myosin V and kinesin, and rotary motors, such as F1-ATPase.

Santos, J E; Parmeggiani, A; Frey, E; Santos, Jaime E.; Franosch, Thomas; Parmeggiani, Andrea; Frey, Erwin

2005-01-01

52

A new vibrational level of the H2+ molecular ion  

International Nuclear Information System (INIS)

A new vibrational level of the molecular ion H2+ with binding energy of 1.09 x 10-9 a.u. ? 30 neV below the first dissociation limit is predicted, using highly accurate numerical non-relativistic quantum calculations, which go beyond the Born-Oppenheimer approximation. It is the first-excited vibrational level v=1 of the 2p?u electronic state, antisymmetric with respect to the exchange of the two protons, with orbital angular momentum L=0. It manifests itself as a huge p - H scattering length of a = 750 ± 5 Bohr radii. (authors)

53

Level crossing in a molecular Cr{sub 8} ring  

Energy Technology Data Exchange (ETDEWEB)

The heat capacity of a molecular Cr{sub 8} ring was measured as a function of temperature and magnetic field in order to follow the evolution of the Schottky anomaly through the first (S=0 to |1,-1>) level crossing occurring at B{sub c1}=6.9 T. The results are interpreted within the framework of a spin Hamiltonian approach and they nicely fit the pattern of the energy levels derived by inelastic neutron spectroscopy. At B{sub c1}, the Schottky anomaly almost vanishes suggesting that a true crossing occurs in Cr{sub 8} in contrast to what was observed for ferric wheels.

Affronte, M. E-mail: affronte@unimore.it; Guidi, T.; Caciuffo, R.; Carretta, S.; Amoretti, G.; Hinderer, J.; Sheikin, I.; Smith, A.A.; Winpenny, R.E.P.; Slageren, J. van; Gatteschi, D

2004-05-01

54

Renormalized molecular levels in a Sc3N@C-80 molecular electronic device  

DEFF Research Database (Denmark)

We address several general questions about quantum transport through molecular systems by an ab initio analysis of a scandium-nitrogen doped C-80 metallofullerene device. Charge transfer from the Sc3N is found to drastically change the current-voltage characteristics: the current through the Sc3N @ C-80 device is double that through a bare C-80 device. We provide strong evidence that transport in such molecular devices is mediated by molecular electronic states which have been renormalized by the device environment, such as the electrodes and external bias V-b. The renormalized molecular levels and main transmission features shift in energy corresponding to half the applied bias voltage. This is also consistent with our finding that the voltage drops by V-b/2 at each molecule/electrode contact.

Larade, Brian; Taylor, Jeremy Philip

2001-01-01

55

Binaural processing of modulated interaural level differences  

DEFF Research Database (Denmark)

Two experiments are presented that measure the acuity of binaural processing of modulated interaural level differences ILDs using psychoacoustic methods. In both experiments, dynamic ILDs were created by imposing an interaurally antiphasic sinusoidal amplitude modulation AM signal on high-frequency carriers, which were presented over headphones. In the first experiment, the sensitivity to dynamic ILDs was measured as a function of the modulation frequency using puretone, and interaurally correlated and uncorrelated narrow-band noise carriers. The intrinsic interaural level fluctuations of the uncorrelated noise carriers raised the ILD modulation detection thresholds with respect to the pure-tone carriers. The diotic fluctuations of the correlated noise carriers also caused a small increase in the thresholds over the pure-tone carriers, particularly with low ILD modulation frequencies. The second experiment investigated the modulation frequency selectivity in dynamic ILD processing by imposing an interaurallyuncorrelated bandpass noise AM masker in series with the interaurally antiphasic AM signal on a pure-tone carrier. By varying the masker center frequencies relative to the signal modulation frequency, broadly tuned, bandpass-shaped patterns were obtained. Simulations with an existing binaural model show that a low-pass filter to limit the binaural temporal resolution is not sufficient to predict the results of the experiments.

Thompson, Eric Robert; Dau, Torsten

2008-01-01

56

Actinide geochemistry: from the molecular level to the real system.  

Science.gov (United States)

Geochemical processes leading to either mobilization or retention of radionuclides in an aquifer system are significantly influenced by their interaction with rock, sediment and colloid surfaces. Therefore, a sound safety assessment of nuclear waste disposal requires the elucidation and quantification of those processes. State-of-the-art analytical techniques as e.g. laser- and X-ray spectroscopy are increasingly applied to study solid-liquid interface reactions to obtain molecular level speciation insight. We have studied the sorption of trivalent lanthanides and actinides onto aluminium oxides, hydroxides and purified clay minerals by the time-resolved laser fluorescence spectroscopy and X-ray-absorption spectroscopy. Chemical constitution and structure of surface bound actinides are proposed based on spectroscopic information. Open questions still remain with regard to the exact nature of mineral surface ligands and the mineral/water interface. Similarities of spectroscopic data obtained for M(III) sorbed onto gamma-alumina, and clay minerals suggest the formation of very comparable inner-sphere surface complexes such as S-O-An(III)(OH)x(2-x)(H2O)5-x at pH > 5. Those speciation data are found consistent with those predicted by surface complexation modelling. The applicability of data obtained for pure mineral phases to actinide sorption onto heterogeneously composed natural clay rock is examined by experiments and by geochemical modelling. Good agreement of experiment and model calculations is found for U(VI) and trivalent actinide/lanthanide sorption to natural clay rock. The agreement of spectroscopy, geochemical modelling and batch experiments with natural rock samples and purified minerals increases the reliability in model predictions. The assessment of colloid borne actinide migration observed in various laboratory and field studies calls for detailed information on actinide-colloid interaction. Kinetic stabilization of colloid bound actinides can be due to inclusion into inorganic colloid matrix or by macromolecular rearrangement in case of organic, humic/fulvic like colloids. Only a combination of spectroscopy, microscopy and classical batch sorption experiments can help to elucidate the actinide-colloid interaction mechanisms and thus contribute to the assessment of colloids for radionuclide migration. PMID:19008017

Geckeis, Horst; Rabung, Thomas

2008-12-12

57

Capillary leveling of stepped films with inhomogeneous molecular mobility  

CERN Document Server

A homogeneous thin polymer film with a stepped height profile levels due to the presence of Laplace pressure gradients. Here we report on studies of polymeric samples with precisely controlled, spatially inhomogeneous molecular weight distributions. The viscosity of a polymer melt strongly depends on the chain length distribution; thus, we learn about thin-film hydrodynamics with viscosity gradients. These gradients are achieved by stacking two films with different molecular weights atop one another. After a sufficient time these samples can be well described as having one dimensional viscosity gradients in the plane of the film, with a uniform viscosity normal to the film. We develop a hydrodynamic model that accurately predicts the shape of the experimentally observed self-similar profiles. The model allows for the extraction of a capillary velocity, the ratio of the surface tension and the viscosity, in the system. The results are in excellent agreement with capillary velocity measurements of uniform mono-...

McGraw, Joshua D; Bäumchen, Oliver; Raphaël, Elie; Dalnoki-Veress, Kari

2013-01-01

58

Improving Molecular Level Chemical Speciation of Organic Aerosols  

Science.gov (United States)

A substantial fraction of fine mode aerosols are organic with the majority formed in the atmosphere through oxidation of gas phase compounds emitted from a variety of natural and man-made sources. As a result, organic aerosols are comprised of thousands of individual organic species whose complexity increases exponentially with carbon number and degree of atmospheric oxidation. Chemical characterization of individual compounds present in this complex mixture provides information on sources and transformation processes that are critical for apportioning organic carbon from an often convoluted mixture of sources and to constrain oxidation mechanisms needed for atmospheric models. These compounds also affect the physical and optical properties of the aerosol but the vast majority remain unidentified and missing from published mass spectral libraries because of difficulties in separating and identifying them. We have developed improved methodologies for chemical identification in order to better understand complex environmental mixtures. Our approach has been to combine two-dimensional gas chromatography with high resolution time of flight mass spectrometry (GC×GC-HRTOFMS) and both traditional electron ionization (EI) and vacuum ultraviolet (VUV) photoionization. GC×GC provides improved separation of individual compounds over traditional one dimensional GC and minimizes co-elution of peaks resulting in mass spectra that are virtually free of interferences. VUV ionization is a ';soft' ionization technique that reduces fragmentation and enhances the abundance of the parent or molecular ion, which when combined with high resolution mass spectrometry can provide molecular formulas for chromatographic peaks. We demonstrate our methodology by applying it to identify more than 500 individual compounds in aerosol filter samples collected at Blodgett Forest, a rural site in the Sierra Nevada Mountains. Using the EI NIST mass spectral library and molecular formulas determined from the high resolution VUV analysis we characterized the observed peaks into those that were: (i) confidently identified by EI and confirmed by VUV (154 compounds), (ii) not matched by EI but assigned molecular formulas from VUV (230), (iii) EI matched but not confirmed by VUV (32), and (iv) not matched by EI and no molecular formula obtained from VUV (92). By combining the molecular formula information with both gas chromatography retention information and the EI mass fragmentation patterns it is possible to characterize previously unidentified compounds in chemically relevant functional group classes. Temporal patterns of all these tracers together provide a new and more complete lens through which to study SOA formation and transformation processes than has previously been possible.

Worton, D. R.; Decker, M.; Isaacman, G. A.; Chan, A.; Wilson, K. R.; Goldstein, A. H.

2013-12-01

59

Molecular basis of lactase levels in adult humans.  

Science.gov (United States)

The molecular basis of adult human "lactase deficiency" has long been a subject of controversy. To address this issue, small intestinal biopsies from orienta, black, and white patients were analyzed. Adjacent samples were assayed for lactase and sucrase specific activities and the sucrase/lactase ratio (high ratio signifies lactase deficiency), and the results were compared to lactase steady-state mRNA levels detected in Northern blots probed with a human lactase mDNA. All oriental patients had high ratios and no detectable lactase mRNA. Four black patients had a similar pattern; two with low ratios had detectable mRNA. The group of white patients displayed a range of findings, from high ratio/no mRNA to low ratio/considerable mRNA. Elevated levels of lactase mRNA always correlated with the presence of elevated levels of lactase enzyme activity, suggesting that the difference in levels of adult human intestinal lactase activity among racial groups may be regulated at the level of gene transcription. PMID:1737837

Escher, J C; de Koning, N D; van Engen, C G; Arora, S; Büller, H A; Montgomery, R K; Grand, R J

1992-02-01

60

Rovibronic energy levels for triplet electronic states of molecular deuterium  

CERN Document Server

Optimal set of 1046 rovibronic energy levels for 35 triplet electronic states of $D_2$ has been obtained by means of statistical analysis of all available values of wavenumbers of rovibronic transitions studied in emission, absorption, laser and anticrossing spectroscopic experiments of various authors. We used new method of the analysis (Lavrov, Ryazanov, JETPLett., 2005), which does not need any a priory assumptions concerning molecular structure being based only on two fundamental principles: maximum likelihood and Rydberg-Ritz. The method provides the opportunity to obtain the estimation of experimental errors of the wavenumbers independent from those reported in original papers. From 3801 published wavenumber values 207 were excluded as blunders, wavenumber values of 122 from them were measured in our experiments. The remaining set of 3716 experimental data has been divided into 14 subsets of uniformly precise data having close to normal error distribution. Unknown shift between levels of ortho- and para...

Lavrov, B P

2007-01-01

61

Identification and analysis of evolutionary selection pressures acting at the molecular level in five forkhead subfamilies  

OpenAIRE

Abstract Background Members of the forkhead gene family act as transcription regulators in biological processes including development and metabolism. The evolution of forkhead genes has not been widely examined and selection pressures at the molecular level influencing subfamily evolution and differentiation have not been explored. Here, in silico methods were used to examine selection pressures acting on the coding sequence of five multi-species FOX protein subfamil...

Rannala Bruce; Fetterman Christina D; Walter Michael A

2008-01-01

62

Hydrodynamical processes in the Draco molecular cloud  

International Nuclear Information System (INIS)

IRAS 100 micron images of the Draco cloud show several cloud components with cometary plumes of material extending 7-10 pc. The brightest plumes are very uniform in thickness but often terminate in large amorphous regions. The structure is consistent with low Reynolds number hydrodynamics and is suggestive of a molecular cloud shedding material in a plume as it falls onto the galactic plane from the halo region. A subsequent study of the 100 micron images from the entire IRAS survey has revealed a total of 14 additional cometlike objects with /b II/ greater then 15 deg. 42 references

63

Optically and thermally induced molecular switching processes at metal surfaces  

International Nuclear Information System (INIS)

Using light to control the switching of functional properties of surface-bound species is an attractive strategy for the development of new technologies with possible applications in molecular electronics and functional surfaces and interfaces. Molecular switches are promising systems for such a route, since they possess the ability to undergo reversible changes between different molecular states and accordingly molecular properties by excitation with light or other external stimuli. In this review, recent experiments on photo- and thermally induced molecular switching processes at noble metal surfaces utilizing two-photon photoemission and surface vibrational spectroscopies are reported. The investigated molecular switches can either undergo a trans-cis isomerization or a ring opening-closure reaction. Two approaches concerning the connection of the switches to the surface are applied: physisorbed switches, i.e. molecules in direct contact with the substrate, and surface-decoupled switches incorporated in self-assembled monolayers. Elementary processes in molecular switches at surfaces, such as excitation mechanisms in photoisomerization and kinetic parameters for thermally driven reactions, which are essential for a microscopic understanding of molecular switching at surfaces, are presented. This in turn is needed for designing an appropriate adsorbate-substrate system with the desired switchable functionality controlled by external stimuli.external stimuli.

64

Optical probes of atomic and molecular decay processes.  

Energy Technology Data Exchange (ETDEWEB)

The study of molecular photoionization and photodissociation dynamics provides insight into the intramolecular mechanisms by which energy and angular momentum are exchanged and redistributed among the internal degrees of freedom of highly excited molecules and, more specifically, into the mechanisms that determine the decay pathways and resulting product-state distributions for the excited molecules. These mechanisms lie at the heart of one of the principal subjects of chemistry, that is, understanding and controlling the factors that govern the making and breaking of chemical bonds. The objective of this experimental research program is to elucidate these fundamental mechanisms and to provide useful prototypes for the development of a general qualitative understanding of their ramifications. In this program, the primary focus is on resonant processes in the ionization and dissociation continua, that is, on autoionization and predissociation. These processes are studied as a function of the electronic, vibrational, and rotational quantum numbers of the resonances, allowing a better understanding of their fundamental mechanisms. In the past three years, the primary emphasis of this experimental program has been on understanding the process of vibrational autoionization in Rydberg states of small polyatomic molecules. Vibrational autoionization corresponds to the decay of resonances above the ionization threshold into the continuum through the conversion of vibrational energy into electronic/translational energy of the highly excited/ejected electron. In polyatomic molecules, I am particularly interested in determining how this process depends on both the specific normal vibrational modes involved in the process and the electronic character of the resonances. In this program, the experimental approach relies on laser-based, double-resonance techniques to prepare the selected excited states in the molecules of interest, and on a variety of detection techniques to characterize both the photoexcitation and subsequent decay processes. These techniques include mass spectrometry, dispersive and threshold photoelectron spectroscopy, laser-induced fluorescence, fluorescence-dip spectroscopy, and laser-induced grating spectroscopy. While the instrumentation is currently available for each of these techniques, two instruments deserve special mention. First, a high-resolution magnetic-bottle electron spectrometer has been developed that is equipped with a pulsed, skimmed molecular beam source. This instrument is capable of {approx}3-4 meV resolution in the electron kinetic energy while providing a collection efficiency of {approx}50%. Second, a time-of-flight mass spectrometer has been constructed with a similar molecular beam source. This instrument is currently being adapted to allow both ion- and electron-imaging studies. A typical experimental study is performed in three steps. First, resonant one-color multiphoton ionization is used to map out the transition between the ground state of the molecule of interest and the low-lying excited state to be used as an intermediate in the double-resonance process. The lasers used in these studies are Nd:YAG-pumped dye lasers with {approx}5 ns pulse durations. In general, this pump transition corresponds to a one- or two-photon process, and the laser output is frequency doubled, tripled, or mixed to generate light in the region of interest. In molecules such as ammonia and aniline, the pump transitions of interest are well characterized, allowing the unambiguous choice of pump transitions that access levels with the rovibronic character of interest. In other cases, the spectroscopy of the pump transition must be analyzed before it can be useful for the double-resonance experiments. In the second step, the pump laser is fixed on the pump transition of interest and a second laser is used to probe transitions from the upper state of the pump transition to the autoionizing or predissociating resonances in the region of interest. The double-resonance spectrum is recorded by scanning the second l

Pratt, S. T. (Chemistry)

2008-01-01

65

Modelling Molecular Mechanisms: A Framework of Scientific Reasoning to Construct Molecular-Level Explanations for Cellular Behaviour  

Science.gov (United States)

Although molecular-level details are part of the upper-secondary biology curriculum in most countries, many studies report that students fail to connect molecular knowledge to phenomena at the level of cells, organs and organisms. Recent studies suggest that students lack a framework to reason about complex systems to make this connection. In this…

van Mil, Marc H. W.; Boerwinkel, Dirk Jan; Waarlo, Arend Jan

2013-01-01

66

Levels of processing: the evolution of a framework  

OpenAIRE

Although the levels of processing framework have evolved over its nearly 40 years of existence, the essence of the idea has not changed from the original. The original article published in 1972 suggests that in the encoding stage of a stimulus, there is a series of processing hierarchies ranging from the shallowest level (perceptual processing—the subject initially perceives the physical and sensory characteristics of the stimulus) to the deepest level (semantic processing—related to patt...

Orlando Francisco Amodeo Bueno; Roberta Ekuni; Leonardo José Vaz

2011-01-01

67

1979 bibliography of atomic and molecular processes. [Bibliography  

Energy Technology Data Exchange (ETDEWEB)

This annotated bibliography lists 2146 works on atomic and molecular processes reported in publications dated 1979. Sources include scientific journals, conference proceedings, and books. Each entry is designated by one or more of the 114 categories of atomic and molecular processes used by the Controlled Fusion Atomic Data Center, Oak Ridge National Laboratory, to classify data. Also indicated is whether the work was experimental or theoretical, what energy range was covered, what reactants were investigated, and the country of origin of the first author. Following the bibliographical listing are indexes of reactants and authors.

None

1980-08-01

68

Status of Safeguards and Separations Model Development at Plant and Molecular Levels  

International Nuclear Information System (INIS)

A primary goal of the Safeguards and Separations IPSC effort is the development of process modeling tools that allow dynamic simulations of separations plant operations under various configurations and conditions, and integration of relevant safeguards analyses. A requirement of the effort is to develop codes on modern, expandable architectures, with flexibility to explore and evaluate a wide range of process options. During FY09, efforts at ORNL have been focused on two priority tasks toward achieving the IPSC goal: (1) a top-down exploration of architecture - Subtask 1: Explore framework for code development and integration for plant-level simulation; and (2) a bottom-up fundamental modeling effort - Subtask 2: Development of molecular-level agent design code. Subtask 1 is important because definition and development of architecture is a key issue for the overall effort, as selection of an overall approach and code/data requirements is a necessary first step in the organization, design and development of separations and safeguards codes that will be incorporated. The agent design effort of Subtask 2 is a molecular-level modeling effort that has a direct impact on a near-term issue of the Separations and Waste Forms Campaign. A current focus of experimental efforts is the development of robust agents and processes for separation of Am/Cm. Development of enhanced agent-design codes will greatly accelerate discovery and experimental testing.ental testing.

69

Solidification process for high level radioactive waste  

International Nuclear Information System (INIS)

Purpose: To integrally solidify high level radioactive wastes with water-curable solidifying material thereby improve the heat- and radiation-resistance. Constitution: High level radioactive wastes are integrally solidified with water curable solidifying material comprising a mixture of alumina cements, aggregates, inorganic fluidizing materials and dispersing agent. Alumina cements are mainly composed of calcium aluminate and excellent in refractory property. Chamotte particles and baked bauxite particles are used as the aggregates, which can improve the strength of the solidification products. Fine alumina powder and fine silica powder of less than 10 ?m radius are used as the inorganic fluidizing materials and condensated phosphoric acid salt and polycarboxylic acid type polymeric surface active agent are used as the dispersing agents for improving the slidability between the particles. (Yoshino, Y.)

70

High-level waste processing and disposal  

International Nuclear Information System (INIS)

The national high-level waste disposal plans for France, the Federal Republic of Germany, Japan, and the United States are covered. Three conclusions are reached. The first conclusion is that an excellent technology already exists for high-level waste disposal. With appropriate packaging, spent fuel seems to be an acceptable waste form. Borosilicate glass reprocessing waste forms are well understood, in production in France, and scheduled for production in the next few years in a number of other countries. For final disposal, a number of candidate geological repository sites have been identified and several demonstration sites opened. The second conclusion is that adequate financing and a legal basis for waste disposal are in place in most countries. Costs of high-level waste disposal will probably add about 5 to 10% to the costs of nuclear electric power. The third conclusion is less optimistic. Political problems remain formidable in highly conservative regulations, in qualifying a final disposal site, and in securing acceptable transport routes

71

The requisite level of theory for the computational design of molecularly imprinted silica xerogels.  

Science.gov (United States)

The present manuscript reports the first application of molecular modelling to the design of molecularly imprinted polymers (MIPs) prepared by alkoxysilane sol-gel polymerization. The major goal was to determine the requisite level of theory for the selection of suitable alkoxysilane functional monomers. A comparative study, applied to the design of a MIP for beta-damascenone, involving different levels of theory, basis set superposition error (BSSE) correction and basis set augmentation and also semi-empirical methods, was performed. The computations results suggest that the use of the 3-21G basis set concomitantly with a method for BSSE correction represents a good compromise between theory level and computation time for the successful screening of functional monomers. Additionally, a few selected MIPs and their corresponding non-imprinted congeners (NIPs) were prepared and tested in the role of solid-phase extraction (SPE) sorbents. The confrontation of the computational results with the observed performance and morphological characteristics of the prepared MIPs suggest that besides the strength and type of interactions existing between template and functional monomers other concomitant features, related with the sol-gel process, must also be accounted for so that effective molecular imprinting is achieved in an alkoxysilane xerogel. Nevertheless, since an optimal template-functional monomer interaction is a necessary condition for successful imprinting, the choice of the best monomers is still of the greatest importance and the proposed computational method may constitute an expeditious and reliable screening tool. PMID:18396031

Azenha, Manuel; Kathirvel, Porkodi; Nogueira, Pedro; Fernando-Silva, António

2008-07-15

72

A Study of molecular cooling via Sisyphus processes  

CERN Document Server

We present a study of Sisyphus cooling of molecules: the scattering of a single-photon remove a substantial amount of the molecular kinetic energy and an optical pumping step allow to repeat the process. A review of the produced cold molecules so far indicates that the method can be implemented for most of them, making it a promising method able to produce a large sample of molecules at sub-mK temperature. Considerations of the required experimental parameters, for instance the laser power and linewidth or the trap anisotropy and dimensionality, are given. Rate equations, as well as scattering and dipolar forces, are solved using Kinetic Monte Carlo methods for several lasers and several levels. For NH molecules, such detailed simulation predicts a 1000-fold temperature reduction and an increase of the phase space density by a factor of 10^7 . Even in the case of molecules with both low Franck-Condon coefficients and a non-closed pumping scheme, 60% of trapped molecules can be cooled from 100 mK to sub-mK tem...

Comparat, Daniel

2014-01-01

73

[Molecular mechanism for dynamic regulation of endogenous ABA signal level].  

Science.gov (United States)

The process from stress signal perception and the trigger of ABA biosynthesis to dynamic regulation of ABA level is an important stress signaling pathway in cells. Compared to the downstream events in ABA signal transduction, the researches in this field are relatively lagged. Expression of synthase genes, such as ZEP in roots and rate-limiting enzyme genes NCED, AtRGS1 and ABA2, can be activated in response to stresses. However, the expression of genes encoding degradative enzymes, including 7'-, 8'-, 9'-hydroxylase and glucosyltransferase, negatively regulates ABA accumulation. Meanwhile, the expressions of the synthases, such as ZEP and NCED3, are induced by increasing endogenous ABA contents. Additionally, the analyses of gene expression and source-sink dynamics indicates that sustained supply from root-sourced ABA is required for the maintenance of leaf ABA dynamic pool. It is notable that miRNAs should be involved in ABA signal origin and ABA level dynamic adjustment. Further dynamic analysis of ABA metabolism revealed that endogenous ABA signal levels are synergistically controlled by the expressions of synthases and degradative enzymes. PMID:22425948

Wei, Kai-Fa; Chen, Juan; Chen, Yan-Feng; Wu, Ling-Juan; Jia, Wen-Suo

2012-03-01

74

Molecular-beam studies of primary photochemical processes  

International Nuclear Information System (INIS)

Application of the method of molecular-beam photofragmentation translational spectroscopy to the investigation of primary photochemical processes of polyatomic molecules is described. Examples will be given to illustrate how information concerning the energetics, dynamics, and mechanism of dissociation processes can be obtained from the precise measurements of angular and velocity distributions of products in an experiment in which a well-defined beam of molecules is crossed with a laser

75

Amino-nitro-azobenzene dimers as a prototype for a molecular-level machine  

International Nuclear Information System (INIS)

Low-temperature scanning tunnelling microscope measurements of an X-shaped dimer, consisting of two amino-nitro-azobenzene molecules, on a Au(111)-surface are presented. Electron-induced manipulation switches either the upper- or the lower-lying molecule. These reversible switching processes are based on the cis-trans isomerization of the azobenzene molecules. The switching of the upper molecule moves the lower-lying molecule in a controlled way. Thus mechanical work is performed. This proof-of-principle shows the ability of azobenzene molecules to act as a molecular-level machine

76

Cisplatin and platinum drugs at the molecular level. (Review).  

Science.gov (United States)

Over twenty years of intensive work toward improvement of cisplatin, and with hundreds of platinum drugs tested, has resulted in the introduction of the widely used carboplatin and of oxaliplatin used only for a very narrow spectrum of cancers. A number of interesting platinum compounds including the orally administered platinum drug JM216, nedaplatin, the sterically hindered platinum(II) complex ZD0473, the trinuclear platinum complex BBR3464, and the liposomal forms Lipoplatin and SPI-77 are under clinical evaluation. This review summarizes the molecular mechanisms of platinum compounds for DNA damage, DNA repair and induction of apoptosis via activation or modulation of signaling pathways and explores the basis of platinum resistance. Cisplatin, carboplatin, oxaliplatin and most other platinum compounds induce damage to tumors via induction of apoptosis; this is mediated by activation of signal transduction leading to the death receptor mechanisms as well as mitochondrial pathways. Apoptosis is responsible for the characteristic nephrotoxicity, ototoxicity and most other toxicities of the drugs. The major limitation in the clinical applications of cisplatin has been the development of cisplatin resistance by tumors. Mechanisms explaining cisplatin resistance include the reduction in cisplatin accumulation inside cancer cells because of barriers across the cell membrane, the faster repair of cisplatin adducts, the modulation of apoptotic pathways in various cells, the upregulation in transcription factors, the loss of p53 and other protein functions and a higher concentration of glutathione and metallothioneins in some type of tumors. A number of experimental strategies to overcome cisplatin resistance are at the preclinical or clinical level such as introduction of the bax gene, inhibition of the JNK pathway, introduction of a functional p53 gene, treatment of tumors with aldose reductase inhibitors and others. Particularly important are combinations of platinum drug treatments with other drugs, radiation and the emerging gene therapy regimens. PMID:14534679

Boulikas, Teni; Vougiouka, Maria

2003-01-01

77

Advances Towards Synthetic Machines at the Molecular and Nanoscale Level  

Directory of Open Access Journals (Sweden)

Full Text Available The fabrication of increasingly smaller machines to the nanometer scale can be achieved by either a “top-down” or “bottom-up” approach. While the former is reaching its limits of resolution, the latter is showing promise for the assembly of molecular components, in a comparable approach to natural systems, to produce functioning ensembles in a controlled and predetermined manner. In this review we focus on recent progress in molecular systems that act as molecular machine prototypes such as switches, motors, vehicles and logic operators.

Kristina Konstas

2010-06-01

78

THE THEORETICAL ASPECTS OF INTEGRATION PROCESSES ON THE REGIONAL LEVEL  

OpenAIRE

In this article theoretical aspects of interregional integration processes are covered. Different approaches areresulted in understanding the essence of integration between separate regions, hierarchical levels of integration,legitimacy use of theories of the international integration is found out at the analysis of regional interrelations. It isoffered the authors approach for the allocation of types of integration processes at a level of region

Yaskal, Ihor; Nedelea, Alexandru

2010-01-01

79

Atomic and molecular processes in JT-60U divertor plasmas  

Energy Technology Data Exchange (ETDEWEB)

Atomic and molecular data are indispensable for the understanding of the divertor characteristics, because behavior of particles in the divertor plasma is closely related to the atomic and molecular processes. In the divertor configuration, heat and particles escaping from the main plasma flow onto the divertor plate along the magnetic field lines. In the divertor region, helium ash must be effectively exhausted, and radiation must be enhanced for the reduction of the heat load onto the divertor plate. In order to exhaust helium ash effectively, the difference between behavior of neutral hydrogen (including deuterium and tritium) and helium in the divertor plasma should be understood. Radiation from the divertor plasma generally caused by the impurities which produced by the erosion of the divertor plate and/or injected by gas-puffing. Therefore, it is important to understand impurity behavior in the divertor plasma. The ions hitting the divertor plate recycle through the processes of neutralization, reflection, absorption and desorption at the divertor plates and molecular dissociation, charge-exchange reaction and ionization in the divertor plasma. Behavior of hydrogen, helium and impurities in the divertor plasmas can not be understood without the atomic and molecular data. In this report, recent results of the divertor study related to the atomic and molecular processes in JT-60U were summarized. Behavior of neural deuterium and helium was discussed in section 2. In section 3, the comparisons between the modelling of the carbon impurity transport and the measurements of C II and C IV were discussed. In section 4, characteristics of the radiative divertor using Ne puffing were reported. The new diagnostic method for the electron density and temperature in the divertor plasmas using the intensity ratios of He I lines was described in section 5. (author)

Takenaga, H.; Shimizu, K.; Itami, K. [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment] [and others

1997-01-01

80

Fermi level alignment in molecular nanojunctions and its relation to charge transfer  

OpenAIRE

The alignment of the Fermi level of a metal electrode within the gap of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of a molecule is a key quantity in molecular electronics, which can vary the electron transparency of a single-molecule junction by orders of magnitude. We present a quantitative analysis of the relation between this level alignment (which can be estimated from charging free molecules) and charge transfer for bipyridine and bi...

Stadler, Robert; Jacobsen, Karsten Wedel

2007-01-01

81

Molecular-Level Design of Heterogeneous Chiral Catalysis  

International Nuclear Information System (INIS)

The following is a proposal to continue our multi-institutional research on heterogeneous chiral catalysis. Our team combines the use of surface-sensitive analytical techniques for the characterization of model systems with quantum and statistical mechanical calculations to interpret experimental data and guide the design of future research. Our investigation focuses on the interrelation among the three main mechanisms by which enantioselectivity can be bestowed to heterogeneous catalysts, namely: (1) by templating chirality via the adsorption of chiral supramolecular assemblies, (2) by using chiral modifiers capable of forming chiral complexes with the reactant and force enantioselective surface reactions, and (3) by forming naturally chiral surfaces using imprinting chiral agents. Individually, the members of our team are leaders in these various aspects of chiral catalysis, but the present program provides the vehicle to generate and exploit the synergies necessary to address the problem in a comprehensive manner. Our initial work has advanced the methodology needed for these studies, including an enantioselective titration procedure to identify surface chiral sites, infrared spectroscopy in situ at the interface between gases or liquids and solids to mimic realistic catalytic conditions, and DFT and Monte Carlo algorithms to simulate and understand chirality on surfaces. The next step, to be funded by the monies requested in this proposal, is to apply those methods to specific problems in chiral catalysis, including the identification of the requirements for the formation of supramolecular surface structures with enantioselective behavior, the search for better molecules to probe the chiral nature of the modified surfaces, the exploration of the transition from supramolecular to one-to-one chiral modification, the correlation of the adsorption characteristics of one-to-one chiral modifiers with their physical properties, in particular with their configuration, and the development of ways to imprint chiral centers on achiral solid surfaces. Chiral catalysis is not only a problem of great importance in its own right, but also the ultimate test of how to control selectivity in catalysis. The time is ripe for fundamental work in heterogeneous chiral catalysis to provide the U.S. with a leadership role in developing the next generation of catalytic processes for medicinal and agrochemical manufacturing. Our team provides the required expertise for a synergistic and comprehensive integration of physical and chemical experimentation with solid state and molecular reactivity theories to solve this problem.

82

Molecular-Level Design of Heterogeneous Chiral Catalysis  

Energy Technology Data Exchange (ETDEWEB)

The following is a proposal to continue our multi-institutional research on heterogeneous chiral catalysis. Our team combines the use of surface-sensitive analytical techniques for the characterization of model systems with quantum and statistical mechanical calculations to interpret experimental data and guide the design of future research. Our investigation focuses on the interrelation among the three main mechanisms by which enantioselectivity can be bestowed to heterogeneous catalysts, namely: (1) by templating chirality via the adsorption of chiral supramolecular assemblies, (2) by using chiral modifiers capable of forming chiral complexes with the reactant and force enantioselective surface reactions, and (3) by forming naturally chiral surfaces using imprinting chiral agents. Individually, the members of our team are leaders in these various aspects of chiral catalysis, but the present program provides the vehicle to generate and exploit the synergies necessary to address the problem in a comprehensive manner. Our initial work has advanced the methodology needed for these studies, including an enantioselective titration procedure to identify surface chiral sites, infrared spectroscopy in situ at the interface between gases or liquids and solids to mimic realistic catalytic conditions, and DFT and Monte Carlo algorithms to simulate and understand chirality on surfaces. The next step, to be funded by the monies requested in this proposal, is to apply those methods to specific problems in chiral catalysis, including the identification of the requirements for the formation of supramolecular surface structures with enantioselective behavior, the search for better molecules to probe the chiral nature of the modified surfaces, the exploration of the transition from supramolecular to one-to-one chiral modification, the correlation of the adsorption characteristics of one-to-one chiral modifiers with their physical properties, in particular with their configuration, and the development of ways to imprint chiral centers on achiral solid surfaces. Chiral catalysis is not only a problem of great importance in its own right, but also the ultimate test of how to control selectivity in catalysis. The time is ripe for fundamental work in heterogeneous chiral catalysis to provide the U.S. with a leadership role in developing the next generation of catalytic processes for medicinal and agrochemical manufacturing. Our team provides the required expertise for a synergistic and comprehensive integration of physical and chemical experimentation with solid state and molecular reactivity theories to solve this problem.

Francisco Zaera

2012-03-21

83

Modelling Molecular Mechanisms: A Framework of Scientific Reasoning to Construct Molecular-Level Explanations for Cellular Behaviour  

Science.gov (United States)

Although molecular-level details are part of the upper-secondary biology curriculum in most countries, many studies report that students fail to connect molecular knowledge to phenomena at the level of cells, organs and organisms. Recent studies suggest that students lack a framework to reason about complex systems to make this connection. In this paper, we present a framework that could help students to reason back and forth between cells and molecules. It represents both the general type of explanation in molecular biology and the research strategies scientists use to find these explanations. We base this framework on recent work in the philosophy of science that characterizes explanations in molecular biology as mechanistic explanations. Mechanistic explanations describe a phenomenon in terms of the entities involved, the activities displayed and the way these entities and activities are organized. We conclude that to describe cellular phenomena scientists use entities and activities at multiple levels between cells and molecules. In molecular biological research, scientists use heuristics based on these intermediate levels to construct mechanistic explanations. They subdivide a cellular activity into hypothetical lower-level activities (top-down approaches) and they predict and test the organization of macromolecules into functional modules that play a role in higher-level activities (bottom-up approaches). We suggest including molecular mechanistic reasoning in biology education and we identify criteria for designing such education. Education using molecular mechanistic reasoning can build on common intuitive reasoning about mechanisms. The heuristics that scientists use can help students to apply this intuitive notion to the levels in between molecules and cells.

van Mil, Marc H. W.; Boerwinkel, Dirk Jan; Waarlo, Arend Jan

2013-01-01

84

Levels of processing: the evolution of a framework  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Although the levels of processing framework have evolved over its nearly 40 years of existence, the essence of the idea has not changed from the original. The original article published in 1972 suggests that in the encoding stage of a stimulus, there is a series of processing hierarchies ranging fro [...] m the shallowest level (perceptual processing-the subject initially perceives the physical and sensory characteristics of the stimulus) to the deepest level (semantic processing-related to pattern recognition and extraction of meaning). The depth processing is associated with high levels of retention and long-term memory traces. After extensive research and criticism, the authors added several concepts that aided in a better understanding of levels of processing framework and the items that subjects can recall such as transfer-appropriate processing and robust encoding. However, there are still some gaps in this framework that call for new scientific investigations, ranging from experimental paradigms with lists of words with healthy or pathological conditions subject to neuroimaging studies to confirm, refute or improve the framework. The aim of this article is to review the publications (articles and book chapters) dating from the original article to the present day to better understand the mnemonic process in terms of levels of processing and to highlight some of its contributions.

Roberta, Ekuni; Leonardo José, Vaz; Orlando Francisco Amodeo, Bueno.

2011-12-01

85

Levels of processing: the evolution of a framework  

Directory of Open Access Journals (Sweden)

Full Text Available Although the levels of processing framework have evolved over its nearly 40 years of existence, the essence of the idea has not changed from the original. The original article published in 1972 suggests that in the encoding stage of a stimulus, there is a series of processing hierarchies ranging from the shallowest level (perceptual processing—the subject initially perceives the physical and sensory characteristics of the stimulus to the deepest level (semantic processing—related to pattern recognition and extraction of meaning. The depth processing is associated with high levels of retention and long-term memory traces. After extensive research and criticism, the authors added several concepts that aided in a better understanding of levels of processing framework and the items that subjects can recall such as transfer-appropriate processing and robust encoding. However, there are still some gaps in this framework that call for new scientific investigations, ranging from experimental paradigms with lists of words with healthy or pathological conditions subject to neuroimaging studies to confirm, refute or improve the framework. The aim of this article is to review the publications (articles and book chapters dating from the original article to the present day to better understand the mnemonic process in terms of levels of processing and to highlight some of its contributions.

Orlando Francisco Amodeo Bueno

2011-07-01

86

Mesoscopic Properties of Molecular Folding and Aggregation Processes  

OpenAIRE

Protein folding, peptide aggregation and crystallization, as well as adsorption of molecules on soft or solid substrates have an essential feature in common: In all these processes, structure formation is guided by a collective, cooperative behavior of the molecular subunits lining up to build chainlike macromolecules. Proteins experience conformational transitions related to thermodynamic phase transitions. For chains of finite length, an important difference of crossovers ...

Bachmann, Michael; Janke, Wolfhard

2009-01-01

87

Separation processes for high-level radioactive waste treatment  

International Nuclear Information System (INIS)

Almost fifty years ago the first nuclear reactor spent fuel was dissolved, as part of the US Manhattan Project, creating a high-level radioactive waste from which plutonium could be extracted. Many methods in many nations have since been found to recover other materials from this waste form, sometimes as minute portions and at others, in much larger quantities. The theme of this session is to look at the separation processes currently being planned to process high-level radioactive waste, then identify alternative processes also being considered. In the United State, high-level radioactive waste currently is stored in underground tanks as liquids, slurry, sludge, and salt cake. Waste quantities, locations, and characteristics are briefly discussed. Because the ultimate disposal of high-level waste in a deep geological repository is inherently expensive, current strategy is to convert major waste volume to low-level waste by the removal of select radionuclides. Several separation processes similar to those common to other industries, such as chemical and mining, are being considered. Although many processing alternatives have been studied, a final flowsheet for high-level radioactive waste treatment has not been selected. For this session, Hanford Site flowsheets are used to establish representative technology requirements and to identify alternative processes currently under investigation. A simplified high-level/low-level split, with the destruction of potentially unit, with the destruction of potentially unsafe materials and removal of a principle heat-producing radionuclide, 137cesium, is presented

88

Intermediate and low-level image processing with M3  

Science.gov (United States)

We have developed a new architecture for computer vision which is a multi-level, MIMD machine. It is a homogenous system where the control unit, processing arrays and image store are all built using the same type of digital signal processor (DSP). DSPs provide satisfactory performance at low-level and intermediate-level image processing and make the construction of a homogenous system possible the processing array of the system consists of three linear arrays. Each linear array is dedicated to one image processing type. The system has a modular design and it can be expanded easily. The overall system design utilizes distributed memory MIMD paradigm. The system is benchmarked with some low- and immediate-level image processing algorithms such as convolution, edge finding. Hough transform etc. and results are presented.

Ercan, M. Fikret; Fung, Yu-Fai; Demokan, M. Suleyman

1997-10-01

89

Simulation analysis of molecular laser isotope separation process for safeguards design  

International Nuclear Information System (INIS)

In this report, firstly an approach to a satisfactory safeguards concept is studied and proposed, among other things, as such that a process model should be developed only on a basis of published theories and data and that the safeguards should be designed using this process model. Secondly, as the first step of this approach, the photon-molecular reaction dynamics for a uranium-235-selective excitation process which is one of the infrared multi-photon dissociation processes for uranium enrichment was computer-simulated using a mathematical model as follows: through the investigation of a selective excitation probability in each energy level and of the transition probability to quasi-continuum levels from the top discrete level, a sensitivity analysis was carried out on the important parameters for process operations such as the optimum relative intensities between the laser for selective excitation and the laser for dissociation, the laser pulse widths to be required, and the asynchronous multi-laser irradiation. As a result, the conditions to be satisfied by such operational parameters in the design of photon-excited selective process were made clear. Although the dissociation process in the quasi-continuum and in the true continuum levels must be investigated in order to have a complete picture of the uranium-235 separation process, the optimization of the photon-excited selective process which was analyzed in this report is the most important theme for the molecular laser uranium enrichment and the detailed analysis of the characteristics of such excitation process not only gives fundamental data for the design of enrichment process but also is necessary for analyzing the diversion possibilities of producing higher enrichment than declared for safeguards design. (author)

90

Space Based Multi-level Process Flow and Logistics Analysis  

Directory of Open Access Journals (Sweden)

Full Text Available In order to thoroughly promote the enterprise digital construction and meet the demand of production management, the space based multi-level process data organization model has been put forward. Firstly, according to the practical division situation of enterprise production space, the multi-level organization method of production space has been proposed. Then through analyzing the manufacturing process of the products in different space layers, the space based multi-level process flow idea has been presented. At the same time, the mathematical model and formalized expression of multi-level technological process have been established. Finally, the in-output material flow relationship between different levels process flow units has been analyzed and the source of input object as well as the disposition of the output object of various level process flow units has been put into detailed analysis. At the mean time, particular statistical sum and trace arithmetic are provided so as to profoundly illustrate the essence of manufacturing process in theory. As a result, the models proposed in this study are not only express the manufacturing process flow of the product in an intuitive and clear way, but also satisfy all types of demands of production management.

Zhou Qiu-Zhong

2013-01-01

91

THOREX processing and zeolite transfer for high-level waste stream processing blending  

International Nuclear Information System (INIS)

The West Valley Demonstration Project (WVDP) completed the pretreatment of the high-level radioactive waste (HLW) prior to the start of waste vitrification. The HLW originated form the two million liters of plutonium/uranium extraction (PUREX) and thorium extraction (THOREX) wastes remaining from Nuclear Fuel Services' (NFS) commercial nuclear fuel reprocessing operations at the Western New York Nuclear Service Center (WNYNSC) from 1966 to 1972. The pretreatment process removed cesium as well as other radionuclides from the liquid wastes and captured these radioactive materials onto silica-based molecular sieves (zeolites). The decontaminated salt solutions were volume-reduced and then mixed with portland cement and other admixtures. Nineteen thousand eight hundred and seventy-seven 270-liter square drums were filled with the cement-wastes produced from the pretreatment process. These drums are being stored in a shielded facility on the site until their final disposition is determined. Over 6.4 million liters of liquid HLW were processed through the pretreatment system. PUREX supernatant was processed first, followed by two PUREX sludge wash solutions. A third wash of PUREX/THOREX sludge was then processed after the neutralized THOREX waste was mixed with the PUREX waste. Approximately 6.6 million curies of radioactive cesium-137 (Cs-137) in the HLW liquid were removed and retained on 65,300 kg of zeolites. With pretreatment complete, the zeolite material has been mobilized, size-reduced (ground), and blended with the PUREX and THOREX sludges in a single feed tank that will supply the HLW slurry to the Vitrification Facility

92

Mechanisms of molecular electronic rectification through electronic levels with strong vibrational coupling  

DEFF Research Database (Denmark)

We present a new view and an analytical formalism of electron flow through a donor-acceptor molecule inserted between a pair of metal electrodes. The donor and acceptor levels are strongly coupled to an environmental nuclear continuum. The formalism applies to molecular donor-acceptor systems both in vacuum or air, and in aqueous solution under electrochemical potential control. Multifarious patterns of rectified electron flow from the negatively to the positively biased electrode arise. The electronic interaction between the donor and acceptor fragments, mutually and with the electrodes, can be weak, corresponding to the fully diabatic limit. The rectification process then reduces to a sequence of vibrationally relaxed single-electron transfer steps. In the limits where the interactions are strong, denoted as the partially and fully adiabatic limits, the character of the rectification process is different, and electron flow proceeds coherently, without vibrational relaxation. In still another class of mechanisms the electronic level broadening of either donor or acceptor from the adjacent electrode is so strong that it is comparable to the vibrational broadening. The process then reduces to a three-level transition similar to STM of large redox molecules. Recent data for rectification in hexadecyl-quinolinium tricyanodimethanide monolayers by Metzger and co-workers [J. Am. Chem. Soc. 119, 10455 (1997); Acc. Chem. Res. 32, 950 (1999)], are discussed in terms of the reported views and formalism.

Kuznetsov, A.M.; Ulstrup, Jens

2002-01-01

93

Renormalized molecular levels in a Sc3N@C-80 molecular electronic device  

OpenAIRE

We address several general questions about quantum transport through molecular systems by an ab initio analysis of a scandium-nitrogen doped C-80 metallofullerene device. Charge transfer from the Sc3N is found to drastically change the current-voltage characteristics: the current through the Sc3N @ C-80 device is double that through a bare C-80 device. We provide strong evidence that transport in such molecular devices is mediated by molecular electronic states which have been renormalized by...

Larade, Brian; Taylor, Jeremy Philip; Zheng, Q. R.; Mehrez, Hatem; Pomorski, Pawel; Guo, Hong

2001-01-01

94

Molecular-level Design of Heterogeneous Chiral Catalysts  

Energy Technology Data Exchange (ETDEWEB)

Understanding and controlling selectivity is one of the key challenges in heterogeneous catalysis. Among problems in catalytic selectivity enantioselectivity is perhaps the most the most challenging. The primary goal of the project on “Molecular-level Design of Heterogeneous Chiral Catalysts” is to understand the origins of enantioselectivity on chiral heterogeneous surfaces and catalysts. The efforts of the project team include preparation of chiral surfaces, characterization of chiral surfaces, experimental detection of enantioselectivity on such surfaces and computational modeling of the interactions of chiral probe molecules with chiral surfaces. Over the course of the project period the team of PI’s has made some of the most detailed and insightful studies of enantioselective chemistry on chiral surfaces. This includes the measurement of fundamental interactions and reaction mechanisms of chiral molecules on chiral surfaces and leads all the way to rationale design and synthesis of chiral surfaces and materials for enantioselective surface chemistry. The PI’s have designed and prepared new materials for enantioselective adsorption and catalysis. Naturally Chiral Surfaces • Completion of a systematic study of the enantiospecific desorption kinetics of R-3-methylcyclohexanone (R-3-MCHO) on 9 achiral and 7 enantiomeric pairs of chiral Cu surfaces with orientations that span the stereographic triangle. • Discovery of super-enantioselective tartaric acid (TA) and aspartic acid (Asp) decomposition as a result of a surface explosion mechanism on Cu(643)R&S. Systematic study of super-enantiospecific TA and Asp decomposition on five enantiomeric pairs of chiral Cu surfaces. • Initial observation of the enantiospecific desorption of R- and S-propylene oxide (PO) from Cu(100) imprinted with {3,1,17} facets by L-lysine adsorption. Templated Chiral Surfaces • Initial observation of the enantiospecific desorption of R- and S-PO from Pt(111) and Pd(111) modified by a variety of chiral templates. • Demonstrated enantioselective separation of racemic PO on chemically synthesized chiral gold nanoparticles. • Discovery of zwitterionic adsorption states of amino acids on Pd(111). • First structure determinations of adsorbed amino acids and identification of tetrameric chiral template structures. • Exploration of the enantiospecific interaction of PO and R-3-MCHO adsorption on chirally modified Cu(100), Cu(110) and Cu(111). One-to-One Interactions • Determination of cinchona orientation on Pt surfaces in situ at the solid-liquid interface using FT-IRAS. • Systematic study of the influence of solution properties on the adsorption of modified cinchonas alkaloids onto Pt surfaces. • Correlation of cinchona adsorption with catalytic activity, as affected by concentration, the nature of the solvent, and dissolved gases in the liquid phase. • Measurement of enantioselective chemisorption on 1-(1-naphthyl) ethylamine (NEA) modified Pt(111) and Pd(111) surfaces. • Imaging of chiral docking complexes between NEA and methyl pyruvate on Pd(111). Chiral Catalyst Synthesis • Anchoring of cinchona alkaloid to surfaces • Synthesis of chiral Au nanoparticles and demonstration of their enantiospecific interactions with R- and S-PO. • Elucidation of the driving forces for chiral imprinting of Cu(100) by L- and D-lysine to form Cu(3,1,17)R&S facets.

Gellman, Andrew John [Carnegie Mellon University; Sholl, David S. [Georgia Institute of Technology; Tysoe, Wilfred T. [University of Wisconsin - Milwaukee; Zaera, Francisco [University of California at Riverside

2013-04-28

95

In-Line Detection and Measurement of Molecular Contamination in Semiconductor Process Solutions  

Science.gov (United States)

This paper discusses a fully automated metrology tool for detection and quantitative measurement of contamination, including cationic, anionic, metallic, organic, and molecular species present in semiconductor process solutions. The instrument is based on an electrospray ionization time-of-flight mass spectrometer (ESI-TOF/MS) platform. The tool can be used in diagnostic or analytical modes to understand process problems in addition to enabling routine metrology functions. Metrology functions include in-line contamination measurement with near real-time trend analysis. This paper discusses representative organic and molecular contamination measurement results in production process problem solving efforts. The examples include the analysis and identification of organic compounds in SC-1 pre-gate clean solution; urea, NMP (N-Methyl-2-pyrrolidone) and phosphoric acid contamination in UPW; and plasticizer and an organic sulfur-containing compound found in isopropyl alcohol (IPA). It is expected that these unique analytical and metrology capabilities will improve the understanding of the effect of organic and molecular contamination on device performance and yield. This will permit the development of quantitative correlations between contamination levels and process degradation. It is also expected that the ability to perform routine process chemistry metrology will lead to corresponding improvements in manufacturing process control and yield, the ability to avoid excursions and will improve the overall cost effectiveness of the semiconductor manufacturing process.

Wang, Jason; West, Michael; Han, Ye; McDonald, Robert C.; Yang, Wenjing; Ormond, Bob; Saini, Harmesh

2005-09-01

96

A new vibrational level of the H$_2^+$ molecular ion  

OpenAIRE

A new state of the H$_2^+$ molecular ion with binding energy of 1.09$\\times10^{-9}$ a.u. below the first dissociation limit is predicted, using highly accurate numerical nonrelativistic quantum calculations. It is the first L=0 excited state, antisymmetric with respect to the exchange of the two protons. It manifests itself as a huge p-H scattering length of $a=750\\pm 5$ Bohr radii.

Carbonell, Jaume; Lazauskas, Rimantas; Delande, Dominique; Hilico, Laurent; K?l?c?, Senem

2002-01-01

97

High-Level Waste System Process Interface Description  

International Nuclear Information System (INIS)

The High-Level Waste System is a set of six different processes interconnected by pipelines. These processes function as one large treatment plant that receives, stores, and treats high-level wastes from various generators at SRS and converts them into forms suitable for final disposal. The three major forms are borosilicate glass, which will be eventually disposed of in a Federal Repository, Saltstone to be buried on site, and treated water effluent that is released to the environment

98

High-Level Waste System Process Interface Description  

Energy Technology Data Exchange (ETDEWEB)

The High-Level Waste System is a set of six different processes interconnected by pipelines. These processes function as one large treatment plant that receives, stores, and treats high-level wastes from various generators at SRS and converts them into forms suitable for final disposal. The three major forms are borosilicate glass, which will be eventually disposed of in a Federal Repository, Saltstone to be buried on site, and treated water effluent that is released to the environment.

d' Entremont, P.D.

1999-01-14

99

The influence of molecular weight in radiotracers of inflamators processes  

International Nuclear Information System (INIS)

Four 99mTc-radiopharmaceuticals (RPs) were compared as a radiotracers of inflammatory process. The RPs were divided in two groups according to their molecular weights and nature. One group included the human IgG and the ior t3 MoAb (anti-CD3), another included the Ciprofloxacine and the DMSA. The RPs were studied by different quality controls, and a biodistribution study in an aseptic inflammatory model made by steril Carragenin. The results obtained in the reduction of the immunoglobulins with 2-mercaptoethanol and sodium metabisulphite demonstrated that both reducing agents were equivalent, because the radiochemical purity obtained were similar and independent of the immunoglobulins. The biodistribution demonstrated a higher incorporation for the radiopharmaceuticals of high molecular weight, and the highest values were obtained with the 2-mercaptoethanol

100

Application of statistical process control to qualitative molecular diagnostic assays  

LENUS (Irish Health Repository)

Modern pathology laboratories and in particular high throughput laboratories such as clinical chemistry have developed a reliable system for statistical process control (SPC). Such a system is absent from the majority of molecular laboratories and where present is confined to quantitative assays. As the inability to apply SPC to an assay is an obvious disadvantage this study aimed to solve this problem by using a frequency estimate coupled with a confidence interval calculation to detect deviations from an expected mutation frequency. The results of this study demonstrate the strengths and weaknesses of this approach and highlight minimum sample number requirements. Notably, assays with low mutation frequencies and detection of small deviations from an expected value require greater sample numbers to mitigate a protracted time to detection. Modeled laboratory data was also used to highlight how this approach might be applied in a routine molecular laboratory. This article is the first to describe the application of SPC to qualitative laboratory data.

O'Brien, Cathal P.

2014-11-01

101

Cascading Activation across Levels of Representation in Children's Lexical Processing  

Science.gov (United States)

Recent work in adult psycholinguistics has demonstrated that activation of semantic representations begins long before phonological processing is complete. This incremental propagation of information across multiple levels of analysis is a hallmark of adult language processing but how does this ability develop? In two experiments, we elicit…

Huang, Yi Ting; Snedeker, Jesse

2011-01-01

102

Multiscale mechanobiology: mechanics at the molecular, cellular, and tissue levels.  

Science.gov (United States)

Mechanical force is present in all aspects of living systems. It affects the conformation of molecules, the shape of cells, and the morphology of tissues. All of these are crucial in architecture-dependent biological functions. Nanoscience of advanced materials has provided knowledge and techniques that can be used to understand how mechanical force is involved in biological systems, as well as to open new avenues to tailor-made bio-mimetic materials with desirable properties.In this article, we describe models and show examples of how force is involved in molecular functioning, cell shape patterning, and tissue morphology. PMID:23731596

Guo, Chin-Lin; Harris, Nolan C; Wijeratne, Sithara S; Frey, Eric W; Kiang, Ching-Hwa

2013-01-01

103

High-Level Waste (HLW) Feed Process Control Strategy  

International Nuclear Information System (INIS)

The primary purpose of this document is to describe the overall process control strategy for monitoring and controlling the functions associated with the Phase 1B high-level waste feed delivery. This document provides the basis for process monitoring and control functions and requirements needed throughput the double-shell tank system during Phase 1 high-level waste feed delivery. This document is intended to be used by (1) the developers of the future Process Control Plan and (2) the developers of the monitoring and control system

104

High Speed Data Processing for Imaging MS-Based Molecular Histology Using Graphical Processing Units  

Science.gov (United States)

Imaging MS enables the distributions of hundreds of biomolecular ions to be determined directly from tissue samples. The application of multivariate methods, to identify pixels possessing correlated MS profiles, is referred to as molecular histology as tissues can be annotated on the basis of the MS profiles. The application of imaging MS-based molecular histology to larger tissue series, for clinical applications, requires significantly increased computational capacity in order to efficiently analyze the very large, highly dimensional datasets. Such datasets are highly suited to processing using graphical processor units, a very cost-effective solution for high speed processing. Here we demonstrate up to 13× speed improvements for imaging MS-based molecular histology using off-the-shelf components, and demonstrate equivalence with CPU based calculations. It is then discussed how imaging MS investigations may be designed to fully exploit the high speed of graphical processor units.

Jones, Emrys A.; van Zeijl, René J. M.; Andrén, Per E.; Deelder, André M.; Wolters, Lex; McDonnell, Liam A.

2012-04-01

105

Molecular collision processes in the presence of picosecond laser pulses  

Science.gov (United States)

Radiative transitions in molecular collision processes taking place in the presence of picosecond pulses are studied within a semiclassical formalism. An expression for adiabatic potential surfaces in the electronic-field representation is obtained, which directly leads to the evaluation of transition probabilities. Calculations with a Landau-Zener-type model indicate that picosecond pulses can be much more effective in inducing transitions than a single long pulse of the same intensity and the same total energy, if the intensity is sufficiently high that the perturbation treatment is not valid.

Lee, H. W.; George, T. F.

1979-01-01

106

Molecular-level changes of aqueous poly(N-isopropylacrylamide) in phase transition.  

Science.gov (United States)

We report a Compton scattering study on the molecular-level structural changes of aqueous poly(N-isopropylacrylamide) (PNIPAM) across the conformational phase transition. PNIPAM is a thermoresponsive polymer that changes its conformation in water from the hydrophilic coil state to the collapsed hydrophobic globule state at 32 °C. Combined with density functional theory calculations, the Compton scattering experiments detect two type of changes in the phase transition. The amount of hydrogen bonds is found to reduce, and an elongation of the internal covalent bond lengths is observed. The elongation of the bonds indicates that not only the hydrogen bonding changes but there are other processes, most likely related to hydrophobic interaction, that should be taken into account in the phase transition. PMID:24786724

Juurinen, Iina; Galambosi, Szabolcs; Anghelescu-Hakala, Adina G; Koskelo, Jaakko; Honkimäki, Veijo; Hämäläinen, Keijo; Huotari, Simo; Hakala, Mikko

2014-05-22

107

Levels of processing and Eye Movements: A Stimulus driven approach  

DEFF Research Database (Denmark)

The aim of this research is to investigate the explication of levels of attention through eye movement parameters. Previous research from disparate fields have suggested that eye movements are related to cognitive processing, however, the exact nature of the relationship is unclear. Since eye movements can be controlled either by bottom up stimulus properties or by top down cognitive control, studies have compared eye movements in real world tasks and searched for indicators of cognitive load or level of attention when task demands increase. Extracting the effects of cognitive processing on eye movements from the effect of the changing nature of the stimulus is difficult. Characterising and confirming the parameters of levels of processing in eye movements requires measures with the explicit intention of systematically varying task demands while also taking account of individual differences. This series of studies attempts to provide explanatory information for previous findings that saccade amplitude and fixation duration are indicative of levels of processing and to isolate top down influences on eye movements with a stimulus driven approach. This approach involves developing measures suitable for studying individual differences in attention in large sample groups, using stimulus pairs which are similar in terms of bottom up properties but different in terms of higher level processing. These methods are presented in study 1, stimuli are developed and tested in Study 2. Study 3 uses these stimuli to investigate individual differences in levels of processing within the normal population using existing constructs and tests of cognitive style. Study 4 investigates these stimuli and the eye movements of a clinical group with known interruption to the dorsal stream of processing, and subsequent isolated difficulty with certain aspects of visual cognition. Results are presented in terms of the development of methods for assessing and tracking individual differences in cognition and subjectiveattentional states in real time through eye movement analysis.

Mulvey, Fiona Bríd

2014-01-01

108

Charge transfer processes: the role of optimized molecular orbitals.  

Science.gov (United States)

The influence of the molecular orbitals on charge transfer (CT) reactions is analyzed through wave function-based calculations. Characteristic CT processes in the organic radical 2,5-di-tert-butyl-6-oxophenalenoxyl linked with tetrathiafulvalene and the inorganic crystalline material LaMnO3 show that changes in the inner shells must be explicitly taken into account. Such electronic reorganization can lead to a reduction of the CT vertical transition energy up to 66%. A state-specific approach accessible through an adapted CASSCF (complete active space self-consistent field) methodology is capable of reaching good agreement with the experimental spectroscopy of CT processes. A partitioning of the relaxation energy in terms of valence- and inner-shells is offered and sheds light on their relative importance. This work paves the way to the intimate description of redox reactions using quantum chemistry methods. PMID:24781811

Meyer, Benjamin; Domingo, Alex; Krah, Tim; Robert, Vincent

2014-08-01

109

Simulation of deacidification process by molecular distillation of deodorizer distillate  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: English Abstract in english A computer program has been developed to simulate the deacidification of sunflower deodorizer distillate. The developed mathematical model is based on momentum, mass and energy balances. The Langmuir-Knudsen constitutive equation was used in order to represent the kinetics of evaporation and condens [...] ation. Physical and transport properties have been evaluated using correlations, which are functions of temperature and composition. The obtained partial differential equation system was solved by means of the Crank-Nicholson technique, and the calculation programs employed were developed and debugged using Matlab 7.1. The mathematical model was used to analyze the phenomena that take place during the molecular distillation process, and it also allowed studying the influence of operating variables on the performance of the process. In this investigation, we analyzed the influence of the operating temperature on purity and yield of the components. Trials at three evaporating temperatures (110 ºC, 130 ºC, and 140 ºC) were carried out in a KDL4 (UIC) molecular distillation apparatus to verify the model.

M. A., Marttinello; I., Leone; M., Pramparo.

2008-12-01

110

Method of processing high level radioactive liquid waste  

International Nuclear Information System (INIS)

High level radioactive liquid wastes formed from re-processing plants are cleaned being frozen in a freezing step. Frozen products of high level radioactive liquid wastes are put to a heated, pressurized and evacuated state in a sublimation step and nitric acid, water, subliming nuclides, etc. are sublimated from the frozen products. They are condensated in a condenser into liquid condensates. Then, a solution of sodium hydroxide is added to the residues and they are separated in a solid-liquid separation step into solutions such as of sodium nitrate and sodium hydroxide and residues mainly comprising nuclear fission products, actinoide elements and corrosion products in the re-processing step. Then, the residues are dried and calcined to form nitrates, drying and calcinating products, etc. of such shape and volume as easy to be stored. Accordingly, as compared with the case of directly processing high level radioactive liquid wastes, the amount of solidification products can be reduced remarkably. (I.N.)

111

Effect of Bread Making Process on Aflatoxin Level Changes  

Directory of Open Access Journals (Sweden)

Full Text Available Wheat flour is a commodity with a high risk of aflatoxins (AFs contamination. During the bread making there are many processes that can affect the AFs stability. The effect of bread making process using different yeast types on AFs levels was investigated. For this purpose, standards of AFs including B and Gwere added to flour and then bread loaves were prepared. Three types of commercially available yeast including active dry yeast, instant dry yeast and compressed yeast were used for dough preparation. AFs levels in flour, dough, and bread were analyzed by high performance liquid chromatography (HPLC with fluorescence detector. The results showed that maximum reduction in aflatoxin levels observed during first proof while the least decline was seen for the baking stage. The order of AFs reduction in bread making process was AFB1>AFB2>AFG1. Furthermore, the results indicated that the most effective yeast for AFs reduction was instant dry yeast.

Jafar Milani

2014-11-01

112

Quantification of chromatin condensation level by image processing.  

Science.gov (United States)

The level of chromatin condensation is related to the silencing/activation of chromosomal territories and therefore impacts on gene expression. Chromatin condensation changes during cell cycle, progression and differentiation, and is influenced by various physicochemical and epigenetic factors. This study describes a validated experimental technique to quantify chromatin condensation. A novel image processing procedure is developed using Sobel edge detection to quantify the level of chromatin condensation from nuclei images taken by confocal microscopy. The algorithm was developed in MATLAB and used to quantify different levels of chromatin condensation in chondrocyte nuclei achieved through alteration in osmotic pressure. The resulting chromatin condensation parameter (CCP) is in good agreement with independent multi-observer qualitative visual assessment. This image processing technique thereby provides a validated unbiased parameter for rapid and highly reproducible quantification of the level of chromatin condensation. PMID:24099693

Irianto, Jerome; Lee, David A; Knight, Martin M

2014-03-01

113

Level sets and extrema of random processes and fields  

CERN Document Server

A timely and comprehensive treatment of random field theory with applications across diverse areas of study Level Sets and Extrema of Random Processes and Fields discusses how to understand the properties of the level sets of paths as well as how to compute the probability distribution of its extremal values, which are two general classes of problems that arise in the study of random processes and fields and in related applications. This book provides a unified and accessible approach to these two topics and their relationship to classical theory and Gaussian processes and fields, and the most modern research findings are also discussed. The authors begin with an introduction to the basic concepts of stochastic processes, including a modern review of Gaussian fields and their classical inequalities. Subsequent chapters are devoted to Rice formulas, regularity properties, and recent results on the tails of the distribution of the maximum. Finally, applications of random fields to various areas of mathematics a...

Azais, Jean-Marc

2009-01-01

114

Levels-Of-Processing Effect on Word Recognition in Schizophrenia  

Science.gov (United States)

Background Individuals with schizophrenia have difficulty organizing words semantically to facilitate encoding. This is commonly attributed to organizational rather than semantic processing limitations. By requiring participants to classify and encode words on either a shallow (e.g., uppercase/lowercase) or deep level (e.g., concrete/abstract), the levels-of-processing paradigm eliminates the need to generate organizational strategies. Methods This paradigm was administered to 30 patients with schizophrenia and 30 healthy comparison subjects to test whether providing a strategy would improve patient performance. Results Word classification during shallow and deep encoding was slower and less accurate in patients. Patients also responded slowly during recognition testing and maintained a more conservative response bias following deep encoding; however, both groups showed a robust levels-of-processing effect on recognition accuracy, with unimpaired patient performance following both shallow and deep encoding. Conclusions This normal levels-of-processing effect in the patient sample suggests that semantic processing is sufficiently intact for patients to benefit from organizational cues. Memory remediation efforts may therefore be most successful if they focus on teaching patients to form organizational strategies during initial encoding. PMID:14643082

Ragland, J. Daniel; Moelter, Stephen T.; McGrath, Claire; Hill, S. Kristian; Gur, Raquel E.; Bilker, Warren B.; Siegel, Steven J.; Gur, Ruben C.

2015-01-01

115

Studying genetic regulatory networks at the molecular level: delayed reaction stochastic models.  

Science.gov (United States)

Current advances in molecular biology enable us to access the rapidly increasing body of genetic information. It is still challenging to model gene systems at the molecular level. Here, we propose two types of reaction kinetic models for constructing genetic networks. Time delays involved in transcription and translation are explicitly considered to explore the effects of delays, which may be significant in genetic networks featured with feedback loops. One type of model is based on delayed effective reactions, each reaction modeling a biochemical process like transcription without involving intermediate reactions. The other is based on delayed virtual reactions, each reaction being converted from a mathematical function to model a biochemical function like gene inhibition. The latter stochastic models are derived from the corresponding mean-field models. The former ones are composed of single gene expression modules. We thus design a model of gene expression. This model is verified by our simulations using a delayed stochastic simulation algorithm, which accurately reproduces the stochastic kinetics in a recent experimental study. Various simplified versions of the model are given and evaluated. We then use the two methods to study the genetic toggle switch and the repressilator. We define the "on" and "off" states of genes and extract a binary code from the stochastic time series. The binary code can be described by the corresponding Boolean network models in certain conditions. We discuss these conditions, suggesting a method to connect Boolean models, mean-field models, and stochastic chemical models. PMID:17350653

Zhu, Rui; Ribeiro, Andre S; Salahub, Dennis; Kauffman, Stuart A

2007-06-21

116

Document authentication at molecular levels using desorption atmospheric pressure chemical ionization mass spectrometry imaging.  

Science.gov (United States)

Molecular images of documents were obtained by sequentially scanning the surface of the document using desorption atmospheric pressure chemical ionization mass spectrometry (DAPCI-MS), which was operated in either a gasless, solvent-free or methanol vapor-assisted mode. The decay process of the ink used for handwriting was monitored by following the signal intensities recorded by DAPCI-MS. Handwritings made using four types of inks on four kinds of paper surfaces were tested. By studying the dynamic decay of the inks, DAPCI-MS imaging differentiated a 10-min old from two 4 h old samples. Non-destructive forensic analysis of forged signatures either handwritten or computer-assisted was achieved according to the difference of the contour in DAPCI images, which was attributed to the strength personalized by different writers. Distinction of the order of writing/stamping on documents and detection of illegal printings were accomplished with a spatial resolution of about 140 µm. A Matlab® written program was developed to facilitate the visualization of the similarity between signature images obtained by DAPCI-MS. The experimental results show that DAPCI-MS imaging provides rich information at the molecular level and thus can be used for the reliable document analysis in forensic applications. PMID:24078245

Li, Ming; Jia, Bin; Ding, Liying; Hong, Feng; Ouyang, Yongzhong; Chen, Rui; Zhou, Shumin; Chen, Huanwen; Fang, Xiang

2013-09-01

117

INTEGRATING CMMI MATURITY LEVEL-3 IN TRADITIONAL SOFTWARE DEVELOPMENT PROCESS  

OpenAIRE

CMMI defines the practices that are specially implemented by software development businesses to achievesuccess. Practices includes topics that direct about eliciting and managing requirements, decision making,measuring performance, planning work, handling risks, and more. In this paper we will discuss CapabilityMaturity Model Integration (CMMI) software process improvement maturity model and the process areasat various levels of CMMI in brief. The main emphasis of the paper is to discuss abou...

Reena Dadhich; Ujala Chauhan

2012-01-01

118

Molecular-level tradeoffs and metabolic adaptation to simultaneous stressors  

OpenAIRE

Life is a dynamic process driven by the complex interplay between physical constraints and selection pressures, ranging from nutrient limitation to inhibitory substances to predators. These stressors are not mutually exclusive; microbes have faced concurrent challenges for eons. Genome-enabled systems biology approaches are adapting economic and ecological concepts like tradeoff curves and strategic resource allocation theory to analyze metabolic adaptations to simultaneous stressors. These m...

Carlson, Ross P.; Taffs, Reed L.

2010-01-01

119

Update of technologies for examining the stratum corneum at the molecular level.  

Science.gov (United States)

Understanding the molecular organization of the stratum corneum is still an outstanding problem, despite being both fundamentally and clinically significant. There is a need to develop methodology that yields molecular-level resolution of the stratum corneum components in their native state, without introducing artefacts. We outline here the recent success of cryo-electron microscopy of vitreous sections (CEMOVIS) combined with electron microscopy simulation to elucidate the molecular organization of the stratum corneum in its near-native state. Furthermore, some emerging technologies for studying the physical properties and dynamic behaviour of native stratum corneum at the molecular level are briefly reviewed. These encompass multiphoton microscopy (MPM), polarization transfer solid-state nuclear magnetic resonance (PTssNMR) and PeakForce tapping-mode atomic force microscopy combined with frequency-modulation Kelvin probe force microscopy (KPFM). CEMOVIS combined with electron microscopy simulation allows for molecular structure determination in situ in native stratum corneum, while MPM allows probing of the stratum corneum local physicochemical properties such as fluorophore diffusion coefficients, water content and pH. PTssNMR allows for evaluation of the molecular mobility of stratum corneum keratin and lipid components, and PeakForce KPFM allows for analysis of the local nanomechanical properties of stratum corneum. These emerging techno-logies may contribute to a molecular-level understanding of stratum corneum structure and function in vivo. PMID:25234173

Norlén, L

2014-09-01

120

Process Analysis and Level Measurement of Textbooks Use by Teachers  

Science.gov (United States)

Teachers and textbooks are two important elements in curriculum implementation. Based on Concerns-Based Adoption Model (CBAM), a curriculum implementation measurement model designed by G. Hall and S. M. Hord, this paper analyzes the general process of curriculum implementation in terms of textbook use, establishes a model that gauges the level of…

Kong, Fanzhe; Shi, Ningzhong

2009-01-01

121

Family Level Processes in Children's Adaptation to School.  

Science.gov (United States)

The study explored the relationship between mothers' and fathers' pre-kindergarten reports of family cohesion and children's academic and social competence in kindergarten and first grade, to assess the role of family level processes in children's adjustment to school. The family cohesion factor was divided into "disengaged,""cohesive," and…

Johnson, Vanessa J. Kahen

122

Molecular and neural mechanisms of sex pheromone reception and processing in the silkmoth Bombyx mori  

Directory of Open Access Journals (Sweden)

Full Text Available Male moths locate their mates using species-specific sex pheromones emitted by conspecific females. One striking feature of sex pheromone recognition in males is the high degree of specificity and sensitivity at all levels, from the primary sensory processes to behavior. The silkmoth Bombyx mori is an excellent model insect in which to decipher the underlying mechanisms of sex pheromone recognition due to its simple sex pheromone communication system, where a single pheromone component, bombykol, elicits the full sexual behavior of male moths. Various technical advancements that cover all levels of analysis from molecular to behavioral also allow the systematic analysis of pheromone recognition mechanisms. Sex pheromone signals are detected by pheromone receptors expressed in olfactory receptor neurons in the pheromone-sensitive sensilla trichodea on male antennae. The signals are transmitted to the first olfactory processing center, the antennal lobe (AL, and then are processed further in the higher centers (mushroom body and lateral protocerebrum to elicit orientation behavior towards females. In recent years, significant progress has been made elucidating the molecular mechanisms underlying the detection of sex pheromones. In addition, extensive studies of the AL and higher centers have provided insights into the neural basis of pheromone processing in the silkmoth brain. This review describes these latest advances, and discusses what these advances have revealed about the mechanisms underlying the specific and sensitive recognition of sex pheromones in the silkmoth.

TakeshiSakurai

2014-03-01

123

Graphics processing units accelerated semiclassical initial value representation molecular dynamics  

Science.gov (United States)

This paper presents a Graphics Processing Units (GPUs) implementation of the Semiclassical Initial Value Representation (SC-IVR) propagator for vibrational molecular spectroscopy calculations. The time-averaging formulation of the SC-IVR for power spectrum calculations is employed. Details about the GPU implementation of the semiclassical code are provided. Four molecules with an increasing number of atoms are considered and the GPU-calculated vibrational frequencies perfectly match the benchmark values. The computational time scaling of two GPUs (NVIDIA Tesla C2075 and Kepler K20), respectively, versus two CPUs (Intel Core i5 and Intel Xeon E5-2687W) and the critical issues related to the GPU implementation are discussed. The resulting reduction in computational time and power consumption is significant and semiclassical GPU calculations are shown to be environment friendly.

Tamascelli, Dario; Dambrosio, Francesco Saverio; Conte, Riccardo; Ceotto, Michele

2014-05-01

124

INTEGRATING CMMI MATURITY LEVEL-3 IN TRADITIONAL SOFTWARE DEVELOPMENT PROCESS  

Directory of Open Access Journals (Sweden)

Full Text Available CMMI defines the practices that are specially implemented by software development businesses to achievesuccess. Practices includes topics that direct about eliciting and managing requirements, decision making,measuring performance, planning work, handling risks, and more. In this paper we will discuss CapabilityMaturity Model Integration (CMMI software process improvement maturity model and the process areasat various levels of CMMI in brief. The main emphasis of the paper is to discuss about the RiskManagement (RSKM which is one of process area at CMMI level-3. The purpose of Risk Management(RSKM processes is to identify potential problems before they occur so that risk-handling activities can beplanned and invoked as needed across the life of the product or project to mitigate adverse impacts onachieving objectives. The main aim of the paper is to analyse the effect of integrating the CMMI maturitylevel-3(process area -RSKM with the traditional software development process. It represents an attempt toorganize the sources of software development risk around the principal aspects of the softwaredevelopment cycle.

Reena Dadhich

2012-02-01

125

Impact of Uranium Levels ON Sludge Batch 2 Simulant Processing  

International Nuclear Information System (INIS)

The Defense Waste Processing Facility began processing Sludge Batch 2 (SB2) in December of 2001. Since the introduction of the first SRAT batch of SB2, processing issues have been observed in the Sludge Receipt and Adjustment Tank, Slurry Mix Evaporator Melter Feed Tank and the melter. These issues coincided with the start of Batch 209, the first full batch from SB2a5. The issues involved the ability to transfer process slurries and feed the melter, difficulty maintaining heat transfer in the SME, and degradation of the operation of the melter. One of the primary differences between Sludge Batch 2 and the previous Sludge Batches is the increased content of uranium. The Savannah River National Laboratory was requested by DWPF via Technical Task Request HLW/DWPF TTR-02-0035 to determine if the processing issues are related to the elevated levels of uranium in SB21. The work reported here is intended to address only a portion of TTR-0035, specifically the impact of uranium on Sludge Batch 2. This work is governed by a Task Technical and Quality Assurance Plan 2 and an Analytical Study Plan 3. SRNL conducted small-scale tests designed to determine the effect of different levels of uranium on sludge processing at the same redox and stoichiometric factor, 0.20 and 130 respectively. Samples used a series of uranium levels in a simulant of SB2. The samples with different uranium contents were compared with each other before and after undergoing a simulated SRAT cycle processundergoing a simulated SRAT cycle process

126

Surface encapsulation process for managing low-level radioactive wastes  

International Nuclear Information System (INIS)

Current processes for low-level radioactive waste (LLRW) stabilization involve mixing contaminants with a fixative such as cement, asphalt, polyethylene, or vinyl monomers, and subsequently curing the mixtures in containers. These methods give rise to processing difficulties and yield products lacking performance to assure long-term LLRW immobilization. Mixing of LLRW into fixatives is impeded by viscous media and the curing reaction is inhibited by LLRW constituents. Product performance is affected by corrosion of the containers which ultimately expose the cured mixtures to environmental stresses. This process, termed the ''Surface Encapsulation Process,'' circumvents these problems. A thermosetting fixative is employed that mixes readily with LLRW and is highly insensitive to inhibition in curing. The agglomerated mixtures are further stabilized by encapsulation with seamless jackets of corrosion resistant plastic, such as polyethylene. In laboratory-scale investigations, feasibility of the technique was demonstrated for managing a broad spectrum of LLRW simulants including ion-exchange resins, beads, and glasses, and sodium salts. Products tested to date meet all relevant NRC and DOT regulations governing waste fixation. The high waste loadings of the products, use of commodity resins, and processing simplicity indicated our process would provide high performance LLRW stabilization at costs that are competitive to those for processes employing state-of-the-art fixatives. An economic analysis based on managing LLRW generated by commercial power plants (?1,000 MeW) substantiates the competitive process costs advantages

127

Separation processes for high-level radioactive waste treatment  

International Nuclear Information System (INIS)

During World War II, production of nuclear materials in the United States for national defense, high-level waste (HLW) was generated as a byproduct. Since that time, further quantities of HLW radionuclides have been generated by continued nuclear materials production, research, and the commercial nuclear power program. In this paper HLW is defined as the highly radioactive material resulting from the processing of spent nuclear fuel. The HLW is the liquid waste generated during the recovery of uranium and plutonium in a fuel processing plant that generally contains more than 99% of the nonvolatile fission products produced during reactor operation. Since this paper deals with waste separation processes, spent reactor fuel elements that have not been dissolved and further processed are excluded

128

Vibrational spectroscopy for probing molecular-level interactions in organic films mimicking biointerfaces.  

Science.gov (United States)

Investigation into nanostructured organic films has served many purposes, including the design of functionalized surfaces that may be applied in biomedical devices and tissue engineering and for studying physiological processes depending on the interaction with cell membranes. Of particular relevance are Langmuir monolayers, Langmuir-Blodgett (LB) and layer-by-layer (LbL) films used to simulate biological interfaces. In this review, we shall focus on the use of vibrational spectroscopy methods to probe molecular-level interactions at biomimetic interfaces, with special emphasis on three surface-specific techniques, namely sum frequency generation (SFG), polarization-modulated infrared reflection absorption spectroscopy (PM-IRRAS) and surface-enhanced Raman scattering (SERS). The two types of systems selected for exemplifying the potential of the methods are the cell membrane models and the functionalized surfaces with biomolecules. Examples will be given on how SFG and PM-IRRAS can be combined to determine the effects from biomolecules on cell membrane models, which include determination of the orientation and preservation of secondary structure. Crucial information for the action of biomolecules on model membranes has also been obtained with PM-IRRAS, as is the case of chitosan removing proteins from the membrane. SERS will be shown as promising for enabling detection limits down to the single-molecule level. The strengths and limitations of these methods will also be discussed, in addition to the prospects for the near future. PMID:24530000

Volpati, Diogo; Aoki, Pedro H B; Alessio, Priscila; Pavinatto, Felippe J; Miranda, Paulo B; Constantino, Carlos J L; Oliveira, Osvaldo N

2014-05-01

129

Viscous origin of ionic liquids at the molecular level: A quantum chemical insight  

Science.gov (United States)

The viscosity of selected families of ionic liquids has been assessed at the molecular level as a function of the intermolecular interactions using Density Functional Theory together with Atoms-in-a-Molecule and Natural Bond Orbitals approaches. Large ion clusters were studied, with the energetics and topology of interactions being related with experimental viscosity data to infer nanoscopic mechanisms controlling the viscous behavior. The reported results exhibit important information on the molecular basis controlling viscosity, which would allow advancing in the development of low-viscous ionic liquids, through a judicious selection of ion pairs considering their interactions and molecular structure.

García, Gregorio; Atilhan, Mert; Aparicio, Santiago

2014-08-01

130

Effects of molecular structural variants on serum Krebs von den Lungen-6 levels in sarcoidosis  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Serum Krebs von den Lungen-6 (KL-6, which is classified as human mucin-1 (MUC1, is used as a marker of sarcoidosis and other interstitial lung diseases. However, there remain some limitations due to a lack of information on the factors contributing to increased levels of serum KL-6. This study was designed to investigate the factors contributing to increased levels of serum KL-6 by molecular analysis. Methods Western blot analysis using anti-KL-6 antibody was performed simultaneously on the bronchoalveolar lavage fluid (BALF and serum obtained from 128 subjects with sarcoidosis. Results KL-6/MUC1 in BALF showed three bands and five band patterns. These band patterns were associated with the MUC1 genotype and the KL-6 levels. KL-6/MUC1 band patterns in serum were dependent on molecular size class in BALF. Significantly increased levels of serum KL-6, serum/BALF KL-6 ratio and serum soluble interleukin 2 receptor were observed in the subjects with influx of high molecular size KL-6/MUC1 from the alveoli to blood circulation. The multivariate linear regression analysis involving potentially relevant variables such as age, gender, smoking status, lung parenchymal involvement based on radiographical stage and molecular size of KL-6/MUC1 in serum showed that the molecular size of KL-6/MUC1 in serum was significant independent determinant of serum KL-6 levels. Conclusions The molecular structural variants of KL-6/MUC1 and its leakage behavior affect serum levels of KL-6 in sarcoidosis. This information may assist in the interpretation of serum KL-6 levels in sarcoidosis.

Shigemura Masahiko

2012-07-01

131

Charge Transfer, Energy-level ''Lineup'' and Transmission in Molecular Electronic Devices  

Science.gov (United States)

There has been strong interest and significant progress in measuring electron transport through single molecules, due to their potential use in future molecular nanotechnology. Such molecular electronic devices usually involve the adsorption of single or a small group of molecules onto two large metallic electrodes. Understanding the electronic property of such metal-molecule-metal systems at equilibrium therefore provides the starting point for understanding their property under nonzero bias. We present first-principle based calculation of some equilibrium properties of the molecular device formed by a phenyldithiolate molecule bridging two gold electrodes, i.e., charge transfer, energy-level ''lineup'' and transmission. In contrast to previous works, we have used local-spin-density-functional theory with a Gaussian-type orbital basis, which not only allows us to use established techniques in molecular electronic structure theory but also to rationalize the result of computation in terms of the familiar language of bonding and orbital interactions in chemistry. We show that significant charge transfer from the metal to the molecule occurs, involving mostly the end sulfur atoms and localized in the interfacial region. Such charge transfer increases the electrostatic potential in the molecule thus changing the energy level structure and the corresponding charge distribution within the molecule. The interaction between the resulting molecular orbitals and the surface metal states determines the lineup of molecular levels relative to the metal Fermi-level and the transmission through the molecule. Our work also points to the importance of interface ''engineering'' for controlling the charge transfer and therefore the energy-level ''lineup'' in molecular electronic devices.

Xue, Yongqiang; Datta, Supriyo; Ratner, Mark

2001-03-01

132

[Molecular genetic bases of adaptation processes and approaches to their analysis].  

Science.gov (United States)

Great interest in studying the molecular genetic bases of the adaptation processes is explained by their importance in understanding evolutionary changes, in the development ofintraspecific and interspecific genetic diversity, and in the creation of approaches and programs for maintaining and restoring the population. The article examines the sources and conditions for generating adaptive genetic variability and contribution of neutral and adaptive genetic variability to the population structure of the species; methods for identifying the adaptive genetic variability on the genome level are also described. Considerable attention is paid to the potential of new technologies of genome analysis, including next-generation sequencing and some accompanying methods. In conclusion, the important role of the joint use of genomics and proteomics approaches in understanding the molecular genetic bases of adaptation is emphasized. PMID:23662427

Salmenkova, E A

2013-01-01

133

Fermi level alignment in molecular nanojunctions and its relation to charge transfer  

DEFF Research Database (Denmark)

The alignment of the Fermi level of a metal electrode within the gap of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of a molecule is a key quantity in molecular electronics, which can vary the electron transparency of a single-molecule junction by orders of magnitude. We present a quantitative analysis of the relation between this level alignment (which can be estimated from charging free molecules) and charge transfer for bipyridine and biphenyl dithiolate (BPDT) molecules attached to gold leads based on density functional theory calculations. For bipyridine the charge distribution is defined by a balance between electrostatic repulsion effects and the filling of the LUMO, where the molecule loses electrons to the leads. BPDT, on the other hand, gains electrons. As a direct consequence the Fermi level of the metal is found at the energetically higher end of the gap in the transmission function for bipyridine and at its lower end for BPDT.

Stadler, Robert; Jacobsen, Karsten Wedel

2006-01-01

134

Molecular dynamics study on Ar ion bombardment effects in amorphous SiO2 deposition processes  

International Nuclear Information System (INIS)

Argon ion bombardment effects on growing amorphous SiO2 films during reactive sputtering deposition processes were examined based on molecular dynamics (MD) and Monte Carlo (MC) simulation techniques. The system we have considered here is a film that is subject to energetic Ar bombardment while it is formed by surface reactions of Si and O atoms separately supplied at low kinetic energies. It has been found that (1) Ar injections preferentially sputter O atoms from the surface over Si and (2) also have a compressing effect on the growing film during the deposition process. In other words, our MD/MC simulations have demonstrated at the atomic level that, with higher energy Ar injections, an amorphous SiO2 film grown in a reactive sputtering deposition process is denser and more Si rich

135

Parallel Processing: from Low- to High-Level Vision  

Science.gov (United States)

While parallel processors have been constructed to support image processing, these systems are not suitable for kinds of image analysis where pictorial information is encoded in non-raster format, e.g., as object-boundary chains, topological graph structures, or tree data structures. Studies of more general image-analysis systems can be based on a trichotomy of image analysis operations (low-level, intermediate-level, and high-level), in which the operations are characterized by the data structures they manipulate. Two computer systems are discussed each of which offers a means for handling all three categories of operations. The possible impact of these systems on data analysis in astronomy is discussed.

Tanimoto, S. L.

136

West Valley demonstration project: alternative processes for solidifying the high-level wastes  

International Nuclear Information System (INIS)

In 1980, the US Department of Energy (DOE) established the West Valley Solidification Project as the result of legislation passed by the US Congress. The purpose of this project was to carry out a high level nuclear waste management demonstration project at the Western New York Nuclear Service Center in West Valley, New York. The DOE authorized the Pacific Northwest Laboratory (PNL), which is operated by Battelle Memorial Institute, to assess alternative processes for treatment and solidification of the WNYNSC high-level wastes. The Process Alternatives Study is the suject of this report. Two pretreatment approaches and several waste form processes were selected for evaluation in this study. The two waste treatment approaches were the salt/sludge separation process and the combined waste process. Both terminal and interim waste form processes were studied. The terminal waste form processes considered were: borosilicate glass, low-alkali glass, marbles-in-lead matrix, and crystallinolecular potential and molecular dynamics calculations of the effect are yet to be completed. Cous oxide was also investigated. The reaction is first order in nitrite ion, second order in hydrogen ion, and between zero and first order in hydroxylamine monosulfonate, depending on the concentration

137

Levels of processing and language modality specificity in working memory.  

Science.gov (United States)

Neural networks underpinning working memory demonstrate sign language specific components possibly related to differences in temporary storage mechanisms. A processing approach to memory systems suggests that the organisation of memory storage is related to type of memory processing as well. In the present study, we investigated for the first time semantic, phonological and orthographic processing in working memory for sign- and speech-based language. During fMRI we administered a picture-based 2-back working memory task with Semantic, Phonological, Orthographic and Baseline conditions to 11 deaf signers and 20 hearing non-signers. Behavioural data showed poorer and slower performance for both groups in Phonological and Orthographic conditions than in the Semantic condition, in line with depth-of-processing theory. An exclusive masking procedure revealed distinct sign-specific neural networks supporting working memory components at all three levels of processing. The overall pattern of sign-specific activations may reflect a relative intermodality difference in the relationship between phonology and semantics influencing working memory storage and processing. PMID:23287569

Rudner, Mary; Karlsson, Thomas; Gunnarsson, Johan; Rönnberg, Jerker

2013-03-01

138

FEATURES, EVENTS, AND PROCESSES: SYSTEM-LEVEL AND CRITICALITY  

Energy Technology Data Exchange (ETDEWEB)

The primary purpose of this Analysis/Model Report (AMR) is to identify and document the screening analyses for the features, events, and processes (FEPs) that do not easily fit into the existing Process Model Report (PMR) structure. These FEPs include the 3 1 FEPs designated as System-Level Primary FEPs and the 22 FEPs designated as Criticality Primary FEPs. A list of these FEPs is provided in Section 1.1. This AMR (AN-WIS-MD-000019) documents the Screening Decision and Regulatory Basis, Screening Argument, and Total System Performance Assessment (TSPA) Disposition for each of the subject Primary FEPs. This AMR provides screening information and decisions for the TSPA-SR report and provides the same information for incorporation into a project-specific FEPs database. This AMR may also assist reviewers during the licensing-review process.

D.L. McGregor

2000-12-20

139

FEATURES, EVENTS, AND PROCESSES: SYSTEM-LEVEL AND CRITICALITY  

International Nuclear Information System (INIS)

The primary purpose of this Analysis/Model Report (AMR) is to identify and document the screening analyses for the features, events, and processes (FEPs) that do not easily fit into the existing Process Model Report (PMR) structure. These FEPs include the 3 1 FEPs designated as System-Level Primary FEPs and the 22 FEPs designated as Criticality Primary FEPs. A list of these FEPs is provided in Section 1.1. This AMR (AN-WIS-MD-000019) documents the Screening Decision and Regulatory Basis, Screening Argument, and Total System Performance Assessment (TSPA) Disposition for each of the subject Primary FEPs. This AMR provides screening information and decisions for the TSPA-SR report and provides the same information for incorporation into a project-specific FEPs database. This AMR may also assist reviewers during the licensing-review process

140

Fluctuation and radiation processes in bounded plasma-molecular systems  

International Nuclear Information System (INIS)

Theory of fluctuations and spontaneous emission of semi-confined and confined partially-ionized plasma with provision for system nonequilibrium, thermal motion of charged particles, collisions of electrons and ions with neutral and dynamics of a molecular subsystem is developed. Calculation of fluctuation spectra is performed on the basis of the Langevin approach. At that, interaction of electromagnetic fields with atoms and molecules is described with equation of motion of polarization vector of two-level quantum system and induced currents in charged particle subsystems are determined on the basis of probable approach when using the Bhatnagar-Gross-Krook model for describing collisions of electrons and ions with neutral particles. Correlation functions of fluctuation sources related to electron and ion subsystems are determined within the framework of probable approach and correlation functions of polarization sources - on the basis of generalization of fluctuation-dissipative theorem. Effect of active molecules on spectral distribution of fluctuations and emission intensity of half-space and layer of nonequilibrium plasma is investigated

141

Molecular responses during cadmium-induced stress in Daphnia magna: Integration of differential gene expression with higher-level effects  

Energy Technology Data Exchange (ETDEWEB)

DNA microarrays offer great potential in revealing insight into mechanistic toxicity of contaminants. The aim of the present study was (i) to gain insight in concentration- and time-dependent cadmium-induced molecular responses by using a customized Daphnia magna microarray, and (ii) to compare the gene expression profiles with effects at higher levels of biological organization (e.g. total energy budget and growth). Daphnids were exposed to three cadmium concentrations (nominal value of 10, 50, 100 {mu}g/l) for two time intervals (48 and 96 h). In general, dynamic expression patterns were obtained with a clear increase of gene expression changes at higher concentrations and longer exposure duration. Microarray analysis revealed cadmium affected molecular pathways associated with processes such as digestion, oxygen transport, cuticula metabolism and embryo development. These effects were compared with higher-level effects (energy budgets and growth). For instance, next to reduced energy budgets due to a decline in lipid, carbohydrate and protein content, we found an up-regulated expression of genes related to digestive processes (e.g. {alpha}-esterase, cellulase, {alpha}-amylase). Furthermore, cadmium affected the expression of genes coding for proteins involved in molecular pathways associated with immune response, stress response, cell adhesion, visual perception and signal transduction in the present study.

Soetaert, Anneleen [Department of Biology, Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)]. E-mail: anneleen.soetaert@ua.ac.be; Vandenbrouck, Tine [Department of Biology, Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Ven, Karlijn van der [Department of Biology, Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Maras, Marleen [Department of Biology, Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Remortel, Piet van [Department of Mathematics and Informatics, Intelligent Systems Laboratory, University of Antwerp, Middelheimlaan 1, B-2020 Antwerp (Belgium); Blust, Ronny [Department of Biology, Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Coen, Wim M. de [Department of Biology, Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

2007-07-20

142

Molecular responses during cadmium-induced stress in Daphnia magna: Integration of differential gene expression with higher-level effects  

International Nuclear Information System (INIS)

DNA microarrays offer great potential in revealing insight into mechanistic toxicity of contaminants. The aim of the present study was (i) to gain insight in concentration- and time-dependent cadmium-induced molecular responses by using a customized Daphnia magna microarray, and (ii) to compare the gene expression profiles with effects at higher levels of biological organization (e.g. total energy budget and growth). Daphnids were exposed to three cadmium concentrations (nominal value of 10, 50, 100 ?g/l) for two time intervals (48 and 96 h). In general, dynamic expression patterns were obtained with a clear increase of gene expression changes at higher concentrations and longer exposure duration. Microarray analysis revealed cadmium affected molecular pathways associated with processes such as digestion, oxygen transport, cuticula metabolism and embryo development. These effects were compared with higher-level effects (energy budgets and growth). For instance, next to reduced energy budgets due to a decline in lipid, carbohydrate and protein content, we found an up-regulated expression of genes related to digestive processes (e.g. ?-esterase, cellulase, ?-amylase). Furthermore, cadmium affected the expression of genes coding for proteins involved in molecular pathways associated with immune response, stress response, cell adhesion, visual perception and signal transduction in the present study

143

In situ sensing and modeling of molecular events at the cellular level  

Science.gov (United States)

We developed the Atomic Force Microscopy (AFM) based nanorobot in combination with other nanomechanical sensors for the investigation of cell signaling pathways. The AFM nanorobotics hinge on the superior spatial resolution of AFM in imaging and extends it into the measurement of biological processes and manipulation of biological matters. A multiple input single output control system was designed and implemented to solve the issues of nanomanipulation of biological materials, feedback, response frequency and nonlinearity. The AFM nanorobotic system therefore provide the human-directed position, velocity and force control with high frequency feedback, and more importantly it can feed the operator with the real-time imaging of manipulation result from the fast-imaging based local scanning. The use of the system has taken the study of cellular process at the molecular scale into a new level. The cellular response to the physiological conditions can be significantly manifested in cellular mechanics. Dynamic mechanical property has been regarded as biomarkers, sometimes even regulators of the signaling and physiological processes, thus the name mechanobiology. We sought to characterize the relationship between the structural dynamics and the molecular dynamics and the role of them in the regulation of cell behavior. We used the AFM nanorobotics to investigate the mechanical properties in real-time of cells that are stimulated by different chemical species. These reagents could result in similar ion channel responses but distinctive mechanical behaviors. We applied these measurement results to establish a model that describes the cellular stimulation and the mechanical property change, a "two-hit" model that comprises the loss of cell adhesion and the initiation of cell apoptosis. The first hit was verified by functional experiments: depletion of Calcium and nanosurgery to disrupt the cellular adhesion. The second hit was tested by a labeling of apoptotic markers that were revealed by flow cytometry. The model would then be able to decipher qualitatively the molecular dynamics infolded in the regulation of cell behavior. To decipher the signaling pathway quantitatively, we employed a nanomechanical sensor at the bottom of the cell, quartz crystal microbalance with energy dissipation monitoring (QCM-D) to monitor the change at the basal area of the cell. This would provide the real time focal adhesion information and would be used in accordance with the AFM measurement data on the top of the cell to build a more complete mechanical profile during the antibody induced signaling process. We developed a model from a systematic control perspective that considers the signaling cascade at certain stimulation as the controller and the mechanical and structural interaction of the cell as the plant. We firstly derived the plant model based on QCM-D and AFM measurement processes. A signaling pathway model was built on a grey box approach where part of the pathway map was delineated in detail while others were condensed into a single reaction. The model parameters were obtained by extracting the mechanical response from the experiment. The model refinements were conducted by testing a series of inhibition mechanisms and comparing the simulation data with the experimental data. The model was then used to predict the existences of certain reactions that are qualitatively reported in the literature.

Yang, Ruiguo

144

Molecular processes from the AGB to the PN stage  

CERN Document Server

Many complex organic molecules and inorganic solid-state compounds have been observed in the circumstellar shell of stars (both C-rich and O-rich) in the transition phase between Asymptotic Giant Branch (AGB) stars and Planetary Nebulae (PNe). This short (~100-10.000 years) phase of stellar evolution represents a wonderful laboratory for astrochemistry and provides severe constraints on any model of gas-phase and solid-state chemistry. One of the major challenges of present day astrophysics and astrochemistry is to understand the formation pathways of these complex organic molecules and inorganic solid-state compounds (e.g., polycyclic aromatic hydrocarbons, fullerenes, and graphene in the case of a C-rich chemistry and oxides and crystalline silicates in O-rich environments) in space. In this review, I present an observational review of the molecular processes in the late stages of stellar evolution with a special emphasis on the first detections of fullerenes and graphene in PNe.

Garcia-Hernandez, D A

2011-01-01

145

Complex physiological and molecular processes underlying root gravitropism  

Science.gov (United States)

Gravitropism allows plant organs to guide their growth in relation to the gravity vector. For most roots, this response to gravity allows downward growth into soil where water and nutrients are available for plant growth and development. The primary site for gravity sensing in roots includes the root cap and appears to involve the sedimentation of amyloplasts within the columella cells. This process triggers a signal transduction pathway that promotes both an acidification of the wall around the columella cells, an alkalinization of the columella cytoplasm, and the development of a lateral polarity across the root cap that allows for the establishment of a lateral auxin gradient. This gradient is then transmitted to the elongation zones where it triggers a differential cellular elongation on opposite flanks of the central elongation zone, responsible for part of the gravitropic curvature. Recent findings also suggest the involvement of a secondary site/mechanism of gravity sensing for gravitropism in roots, and the possibility that the early phases of graviresponse, which involve differential elongation on opposite flanks of the distal elongation zone, might be independent of this auxin gradient. This review discusses our current understanding of the molecular and physiological mechanisms underlying these various phases of the gravitropic response in roots.

Chen, Rujin; Guan, Changhui; Boonsirichai, Kanokporn; Masson, Patrick H.

2002-01-01

146

SENTINEL-2 Level 1 Products and Image Processing Performances  

Science.gov (United States)

In partnership with the European Commission and in the frame of the Global Monitoring for Environment and Security (GMES) program, the European Space Agency (ESA) is developing the Sentinel-2 optical imaging mission devoted to the operational monitoring of land and coastal areas. The Sentinel-2 mission is based on a satellites constellation deployed in polar sun-synchronous orbit. While ensuring data continuity of former SPOT and LANDSAT multi-spectral missions, Sentinel-2 will also offer wide improvements such as a unique combination of global coverage with a wide field of view (290 km), a high revisit (5 days with two satellites), a high resolution (10 m, 20 m and 60 m) and multi-spectral imagery (13 spectral bands in visible and shortwave infra-red domains). In this context, the Centre National d'Etudes Spatiales (CNES) supports ESA to define the system image products and to prototype the relevant image processing techniques. This paper offers, first, an overview of the Sentinel-2 system and then, introduces the image products delivered by the ground processing: the Level-0 and Level-1A are system products which correspond to respectively raw compressed and uncompressed data (limited to internal calibration purposes), the Level-1B is the first public product: it comprises radiometric corrections (dark signal, pixels response non uniformity, crosstalk, defective pixels, restoration, and binning for 60 m bands); and an enhanced physical geometric model appended to the product but not applied, the Level-1C provides ortho-rectified top of atmosphere reflectance with a sub-pixel multi-spectral and multi-date registration; a cloud and land/water mask is associated to the product. Note that the cloud mask also provides an indication about cirrus. The ground sampling distance of Level-1C product will be 10 m, 20 m or 60 m according to the band. The final Level-1C product is tiled following a pre-defined grid of 100x100 km2, based on UTM/WGS84 reference frame. The stringent image quality requirements are also described, in particular the geo-location accuracy for both absolute (better than 12.5 m) and multi-temporal (better than 0.3 pixels) cases. Then, the prototyped image processing techniques (both radiometric and geometric) will be addressed. The radiometric corrections will be first introduced. They consist mainly in dark signal and detector relative sensitivity correction, crosstalk correction and MTF restoration. Then, a special focus will be done on the geometric corrections. In particular the innovative method of automatic enhancement of the geometric physical model will be detailed. This method takes advantage of a Global Reference Image database, perfectly geo-referenced, to correct the physical geometric model of each image taken. The processing is based on an automatic image matching process which provides accurate ground control points between a given band of the image to refine and a reference image, allowing to dynamically calibrate the viewing model. The generation of the Global Reference Image database made of Sentinel-2 pre-calibrated mono-spectral images will be also addressed. In order to perform independent validation of the prototyping activity, an image simulator dedicated to Sentinel-2 has been set up. Thanks to this, a set of images have been simulated from various source images and combining different acquisition conditions and landscapes (mountains, deserts, cities …). Given disturbances have been also simulated so as to estimate the end to end performance of the processing chain. Finally, the radiometric and geometric performances obtained by the prototype will be presented. In particular, the geo-location performance of the level-1C products which widely fulfils the image quality requirements will be provided.

Baillarin, S. J.; Meygret, A.; Dechoz, C.; Petrucci, B.; Lacherade, S.; Tremas, T.; Isola, C.; Martimort, P.; Spoto, F.

2012-07-01

147

Exploring the energy landscape of the charge transport levels in organic semiconductors at the molecular scale.  

Science.gov (United States)

The extraordinary semiconducting properties of conjugated organic materials continue to attract attention across disciplines including materials science, engineering, chemistry, and physics, particularly with application to organic electronics. Such materials are used as active components in light-emitting diodes, field-effect transistors, or photovoltaic cells, as a substitute for (mostly Si-based) inorganic semiconducting materials. Many strategies developed for inorganic semiconductor device building (doping, p-n junctions, etc.) have been attempted, often successfully, with organics, even though the key electronic and photophysical properties of organic thin films are fundamentally different from those of their bulk inorganic counterparts. In particular, organic materials consist of individual units (molecules or conjugated segments) that are coupled by weak intermolecular forces. The flexibility of organic synthesis has allowed the development of more efficient opto-electronic devices including impressive improvements in quantum yields for charge generation in organic solar cells and in light emission in electroluminescent displays. Nonetheless, a number of fundamental questions regarding the working principles of these devices remain that preclude their full optimization. For example, the role of intermolecular interactions in driving the geometric and electronic structures of solid-state conjugated materials, though ubiquitous in organic electronic devices, has long been overlooked, especially when it comes to these interfaces with other (in)organic materials or metals. Because they are soft and in most cases disordered, conjugated organic materials support localized electrons or holes associated with local geometric distortions, also known as polarons, as primary charge carriers. The spatial localization of excess charges in organics together with low dielectric constant (?) entails very large electrostatic effects. It is therefore not obvious how these strongly interacting electron-hole pairs can potentially escape from their Coulomb well, a process that is at the heart of photoconversion or molecular doping. Yet they do, with near-quantitative yield in some cases. Limited screening by the low dielectric medium in organic materials leads to subtle static and dynamic electronic polarization effects that strongly impact the energy landscape for charges, which offers a rationale for this apparent inconsistency. In this Account, we use different theoretical approaches to predict the energy landscape of charge carriers at the molecular level and review a few case studies highlighting the role of electrostatic interactions in conjugated organic molecules. We describe the pros and cons of different theoretical approaches that provide access to the energy landscape defining the motion of charge carriers. We illustrate the applications of these approaches through selected examples involving OFETs, OLEDs, and solar cells. The three selected examples collectively show that energetic disorder governs device performances and highlights the relevance of theoretical tools to probe energy landscapes in molecular assemblies. PMID:23140088

Cornil, J; Verlaak, S; Martinelli, N; Mityashin, A; Olivier, Y; Van Regemorter, T; D'Avino, G; Muccioli, L; Zannoni, C; Castet, F; Beljonne, D; Heremans, P

2013-02-19

148

Molecular processes affecting the macroscopic tribological behavior of surfaces  

International Nuclear Information System (INIS)

The purpose of this study was to investigate the influence of various additives on the tribological properties of a system in the macro and nanoscale, as well as clarify lubricant interactions with surfaces and materials. To accomplish that a wide range of lubricants and additives were considered. Moreover, a detail chemical analysis was carried out, in order to explain the effect on the friction coefficient, wear mechanisms and corrosion process in lubricated tribosystems. This research was mainly focused on additives for water based lubricants. Solutions of anti-corrosion and anti-foaming agents - amines, friction modifiers - glycols and amines derivatives with longer hydrocarbon chains were investigated. The results showed that the additives build chemisorbed mono-molecular films on surfaces, what was verified by AFM, AR-XPS and AES analysis, and compared with SESSA simulation. Investigated tribo-films affect the friction coefficient in nanoscale, however during tribological test in the macroscale, they showed different results depending on contact situation (rolling and/or sliding). The conclusion states that the differences in tribological behavior might be due to the orientation of amine and hydroxyl groups on the surfaces. Furthermore, lubricants for rolling bearing elements such as polar and non polar oils with zinc dialkyldithiophosphate (ZDDP) additives were studied. The results demonstrated that a reaction layer formation is strongly dependent on the molecumation is strongly dependent on the molecular polarity of the oils and additives. The evolution of the topography and mechanical properties of the ZDDP-derived tribo-layer with rubbing time showed that initially a thin and soft ZDDP reaction layer develops very quick. The second part of this work was addressed on chemical vapor deposited (CVD) diamond films and transition metal dichalcogenides (TMD) in consideration of desired properties for micro electro mechanical systems (MEMS). The main scientific goal of this part of the work was to evaluate the influence of surface morphologies on the micro- and nanomechanical properties. Keeping nanotribological application in mind, a comparative AFM analysis were carried out and the influence of carbon content on the mechanical behaviour of such a coatings was evaluated. (author)

149

Boreal fishes and ultraviolet radiation : actions of UVR at molecular and individual levels  

OpenAIRE

Anthropogenically-caused stratospheric ozone depletion has increased the amount of UVB on Earth, and the predictions in Fennoscandia for the future suggest a further 20–60 % increase in the coming decades. This work explores the effects of UVB on larval boreal freshwater fishes at both the cellular and molecular level, and connects them to impacts at the individual level (mortality and growth retardation). Larval coregonids were very tolerant against UVR, but simultaneous exposure to UVB an...

Vehnia?inen, Eeva-riikka

2005-01-01

150

SUSAN - A new approach to low level image processing  

OpenAIRE

This paper describes a new approach to low level image processing; in particular, edge and corner detection and structure preserving noise reduction. Non-linear filtering is used to define which parts of the image are closely related to each individual pixel; each pixel has associated with it a local image region which is of similar brightness to that pixel. The new feature detectors are based on the minimization of this local image region, and the noise reduction method uses this region as t...

Smith, Sm; Brady, Jm

1997-01-01

151

AP600 low level radioactive waste processing and handling  

International Nuclear Information System (INIS)

The Westinghouse AP600 is a nominal 600 MWE, advanced nuclear plant design with passive safety systems. It is designed for general worldwide installations and suitable for a broad range of environmental conditions. The radioactive waste processing and handling systems presume the existence of modern support infrastructure near the plant. AP600 low level radioactive waste processing and handling systems are categorized into liquid, gaseous and solid radwaste systems. The AP600 does not include boron recycle and relies upon dilution of the boric acid to satisfy local discharge restrictions. There are also no provisions for an in-plant laundry. These simplifications have resulted in reduced initial equipment and operating costs. They have also simplified the operational procedures for the radwaste systems

152

Process modeling of low-level mixed waste vitrification systems  

International Nuclear Information System (INIS)

Chemical process simulators have the potential to combine, in a single calculation, thermodynamic modeling of glass melters with vitrification system material and energy balances. These commercially-available computer codes have been developed for process simulation in the chemical and petroleum industries, i.e., processes which occur primarily in the vapor and liquid phases. As such, they are not oriented towards solid-liquid transition phenomena. They are capable of tracking solids, however, and contain algorithms for complex phase and chemical equilibrium similar to those which underlie codes used in metallurgical thermodynamics. One such chemical process simulator, ASPEN+trademark, is being used to model melter thermodynamics for low-level mixed waste (LLMW) vitrification systems. Such systems are now under development by the Savannah River Technology Center (SRTC) in cooperation with the DOE/Industrial Center for Vitrification Research at Clemson University. This paper reports glass melter model calculations using ASPEN+trademark and compares this tool to STGSOL, a modeling tool which is widely used for high-temperature thermodynamic equilibrium calculations for smelters and glass melters

153

Determination of excitation temperatures for vibrational and rotational molecular levels in an atmospheric pressure gas-discharge plasma  

International Nuclear Information System (INIS)

A procedure for the determination of excitation temperatures of vibrational and rotational molecular levels in an atmospheric-pressure gas-discharge plasma with the use of the SPECAIR computer code has been proposed. To simplify and accelerate the processing of radiation spectra, calibration curves for the determination of vibrational and rotational temperatures by analyzing the emission bands of molecules OH(A- X), N2(C-B), N2+ (B-X), CN(B-X), and C2 (d-a Swan transitions) were plotted. The method developed was tested by evaluating the plasma parameters of a discharge in the gas channel with a liquid wall.

154

Tuning molecular level alignment and work function modification through self-assembled monolayers on noble metals: theoretical perspectives  

International Nuclear Information System (INIS)

Full text: There is currently significant interest in highly-ordered, self-assembled monolayers (SAMs) on (noble) metal surfaces, inspired both by the emergence of the field of molecular electronics alongside the high potential for SAMs to improve the properties of more conventional device structures. SAMs are also used to control surface reactivity and for chemical sensing applications. In order to tune the interface properties and to endow the self-assembled systems with functionality suitable for use in either macroscopic or nanoscale devices, the use of ?-conjugated systems is highly promising and the focus of intense, multidisciplinary research. The goal of the present study is to provide an in-depth description of the electronic structure of the interface between metallic substrates and covalently bound conjugated molecules. In this way, we expect to devise strategies to tune the interaction and thus the properties of the investigated systems and eventually to gain a full understanding of the processes governing the electronics of metal/organic interfaces. Here, we describe a first step in that direction: we study conjugated SAMs consisting of molecules with widely varied molecular ionization potentials, different conjugated backbones with different polarizabilities, and monolayers with varying degrees of coverage. We consider noble metals with varying work functions such as Au, Ag, and Pt, different molecule docking groups and investigate the effects of mechanups and investigate the effects of mechanical stress on the organic system. Using DFT band-structure-type methods, the details of the interface morphology, charge transfer between the metal and the molecules, interface dipoles, molecular layer depolarization, and work function modifications as well as the alignment between metallic and molecular levels are described. Our thorough analysis provides results that are sometimes a priori unexpected, like the finding that by properly tuning the molecular structure, the level alignment between the metal and the organic monolayer can be fully decoupled from the work-function modification induced by the SAM. (author)

155

EOS MLS Level 1B Data Processing Software. Version 3  

Science.gov (United States)

This software is an improvement on Version 2, which was described in EOS MLS Level 1B Data Processing, Version 2.2, NASA Tech Briefs, Vol. 33, No. 5 (May 2009), p. 34. It accepts the EOS MLS Level 0 science/engineering data, and the EOS Aura spacecraft ephemeris/attitude data, and produces calibrated instrument radiances and associated engineering and diagnostic data. This version makes the code more robust, improves calibration, provides more diagnostics outputs, defines the Galactic core more finely, and fixes the equator crossing. The Level 1 processing software manages several different tasks. It qualifies each data quantity using instrument configuration and checksum data, as well as data transmission quality flags. Statistical tests are applied for data quality and reasonableness. The instrument engineering data (e.g., voltages, currents, temperatures, and encoder angles) is calibrated by the software, and the filter channel space reference measurements are interpolated onto the times of each limb measurement with the interpolates being differenced from the measurements. Filter channel calibration target measurements are interpolated onto the times of each limb measurement, and are used to compute radiometric gain. The total signal power is determined and analyzed by each digital autocorrelator spectrometer (DACS) during each data integration. The software converts each DACS data integration from an autocorrelation measurement in the time domain into a spectral measurement in the frequency domain, and estimates separately the spectrally, smoothly varying and spectrally averaged components of the limb port signal arising from antenna emission and scattering effects. Limb radiances are also calibrated.

Perun, Vincent S.; Jarnot, Robert F.; Wagner, Paul A.; Cofield, Richard E., IV; Nguyen, Honghanh T.; Vuu, Christina

2011-01-01

156

Empoderamiento: Proceso, Nivel y Contexto Empowerment: Process, Level, and Context  

Directory of Open Access Journals (Sweden)

Full Text Available En este artículo se discute el fenómeno del empoderamiento y se analiza la distinción teórica entre proceso y resultado de empoderamiento (Zimmerman, 2000. A partir de las formulaciones de este autor y el aporte de una perspectiva interaccional (Bronfenbrenner, 1987, se sostiene que aquella diferenciación es poco viable en términos objetivos y absolutos o de esencia, pero sí útil, en términos analíticos, desde la percepción de la propia comunidad involucrada, que debe ser comprendida por el colaborador externo. También se propone establecer una diferencia entre contexto y nivel de empoderamiento, y analizar el contexto del fenómeno en los niveles individual, organizacional y comunitario del agregado social, lo que aporta claridad a su definición. De esta manera adquiere centralidad la concepción del empoderamiento como proceso en sucesivos contextos que benefician no sólo a los individuos sino que a los colectivos socialesA critical analysis of the concept of empowerment and the theoretical distinction between empowerment process and outcome (Zimmerman, 2000 are presented. Based on Zimmerman's conceptualisation, and the interaccional perspective (Bronfenbrenner, 1987, we argue that the distinction between empowerment process and outcome, though analytically useful (if based on the perception of the community itself from their own experience, which must be understood by professional agent is not always viable in absolute or objective terms. In addition, we suggest to distinguish between context and level of analyses in empowerment theory, and to analyze the context of the empowerment phenomenon at the individual, organizational and community level, which clarifies the definition of each of them. In sum, empowerment is conceived as a process within successive contexts that benefits not only individuals, but also different social aggregate kinds of groups

Carmen Silva

2004-11-01

157

Molecular-Level Insights into Photocatalysis from Scanning Probe Microscopy Studies on TiO2(110)  

Energy Technology Data Exchange (ETDEWEB)

The field of heterogeneous photocatalysis has grown considerably in the decades since Fujishima and Honda's ground-breaking publications of photoelectrochemistry on TiO2. Numerous review articles continue to point to both progress made in the use of heterogeneous materials (such as TiO2) to perform photoconversion processes, and the many opportunities and challenges in heterogeneous photocatalysis research such as solar energy conversion and environmental remediation. The past decade has also seen an increase in the use of molecular-level approaches applied to model single crystal surfaces in an effort to obtain new insights into photocatalytic phenomena. In particular, scanning probe techniques (SPM) have enabled researchers to take a ‘nanoscale’ approach to photocatalysis that includes interrogation of the reactivities of specific sites and adsorbates on a model photocatalyst surface. The rutile TiO2(110) surface has become the prototypical oxide single crystal surface for fundamental studies of many interfacial phenomena. In particular, TiO2(110) has become an excellent model surface for probing photochemical and photocatalytic reactions at the molecular level. A variety of experimental approaches have emerged as being ideally suited for studying photochemical reactions on TiO2(110), including desorption-oriented approaches and electronic spectroscopies, but perhaps the most promising techniques for evaluating site-specific properties are those of SPM. In this review, we highlight the growing use of SPM techniques in providing molecular-level insights into surface photochemistry on the model photocatalyst surface of rutile TiO2(110). Our objective is to both illustrate the unique knowledge that scanning probe techniques have already provided the field of photocatalysis, and also to motivate a new generation of effort into the use of such approaches to obtain new insights into the molecular level details of photochemical events occurring at interfaces. Discussion will start with an examination of how scanning probe techniques are being used to characterize the TiO2(110) surface in ways that are relevant to photocatalysis. We will then discuss specific classes of photochemical reaction on TiO2(110) for which SPM has proven indispensible in providing unique molecular-level insights, and conclude with discussion of future areas in which SPM studies may prove valuable to photocatalysis on TiO2. This work was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. I.L. was partially supported by a Pacific Northwest National Laboratory (PNNL) Chemical Imaging Initiative project. PNNL is a multiprogram national laboratory operated for DOE by Battelle.

Henderson, Michael A.; Lyubinetsky, Igor

2013-06-12

158

Bias-dependent molecular-level structure of electrical double layer in ionic liquid on graphite  

Energy Technology Data Exchange (ETDEWEB)

Bias-dependent structure of electrochemical double layers at liquid-solid interfaces underpin a multitude of phenomena in virtually all areas of scientific enquiry ranging from energy storage and conversion systems, biology, to geophysics and geochemistry. Here we report the bias-evolution of the electric double layer structure of an ionic liquid on highly ordered pyrolytic graphite as a model system for carbon-based electrodes for electrochemical supercapacitors measured by atomic force microscopy. Matching the observed structures to molecular dynamics simulations allows us to resolve steric effects due to cation and anion layers. We observe reconfiguration under applied bias and the orientational transitions in the Stern layer. The synergy between molecular dynamics simulation and experiment provides a comprehensive picture of structural phenomena and long- and short range interactions. This insight will improve understanding of the mechanism of charge storage in electrochemical capacitors on a molecular level which can be used to enhance their electrochemical performance.

Black, Jennifer M [ORNL; Walters, Deron [Asylum Research, Santa Barbara, CA; Labuda, Aleksander [Asylum Research, Santa Barbara, CA; Feng, Guang [ORNL; Hillesheim, Patrick C [ORNL; Dai, Sheng [ORNL; Cummings, Peter T [ORNL; Kalinin, Sergei V [ORNL; Proksch, Roger [Asylum Research, Santa Barbara, CA; Balke, Nina [ORNL

2013-01-01

159

Molecular cytogenetics in an assessment of DNA damage and repair processes  

International Nuclear Information System (INIS)

Mutagenesis is one of the simplest and most effective methods for inducing plant variability. The mechanisms, which evoke variability, are chromosomal aberrations, arising from DNA double strand breaks (DSB). The frequency of chromosomal aberrations is correlated with the level of DNA damage and effectivity of cell repair system. Chromosomal aberrations can be detected using simple cytogenetic methods, however to assess the direct DNA damage and the effectivity of repair processes during recovery time after mutagenic treatment. in nucleus molecular methods are required. Comet assay and TUNEL test were successfully adapted and accepted for the detection of DNA fragmentation in mutagenesis. TUNEL test, based on labelling the 3'OH ends of DNA with fluorochrome - conjugated dUTP by terminal deoxynucleotidyl transferase (TdT) allows to distinguish the nuclei with DNA fragmentation. Another method - comet assay, based on the migration of damaged DNA fragments in electric field and forming an image similar to comet, is used for analysis of the level of DNA damage in single nucleus. Fluorescent in situ hybridization (FISH), provides new tools for the identification of individual chromosomes/chromosome arms participating in formation of the aberration. An advantage of FISH is possibility to understand the composition of the micronuclei thus improving an existing micronucleus test. An application of region-specific DNA probes (telomere and centromere) as well as rDNA as probes and centromere) as well as rDNA as probes enables the analysis of the break points in the chromosomes leading to micronuclei. The application of the molecular cytogenetic methods will be presented as the analysis of the level of DNA damage and effectivity of repair processes in Hordeum vulgare cells (2n=14) after mutagenic treatment with ?-rays, MH, and MNU in different postincubation times. FISH with rDNA and centromeric/telomeric DNA as probes, to evaluate chromosome aberrations in barley cells caused by these mutagens will show the differences between action of these mutagens. (author)

160

Tree-indexed processes: a high level crossing analysis  

Directory of Open Access Journals (Sweden)

Full Text Available Consider a branching diffusion process on R1 starting at the origin. Take a high level u>0 and count the number R(u,n of branches reaching u by generation n. Let Fk,n(u be the probability P(R(u,n

Mark Kelbert

2003-01-01

161

EOS MLS Level 2 Data Processing Software Version 3  

Science.gov (United States)

This software accepts the EOS MLS calibrated measurements of microwave radiances products and operational meteorological data, and produces a set of estimates of atmospheric temperature and composition. This version has been designed to be as flexible as possible. The software is controlled by a Level 2 Configuration File that controls all aspects of the software: defining the contents of state and measurement vectors, defining the configurations of the various forward models available, reading appropriate a priori spectroscopic and calibration data, performing retrievals, post-processing results, computing diagnostics, and outputting results in appropriate files. In production mode, the software operates in a parallel form, with one instance of the program acting as a master, coordinating the work of multiple slave instances on a cluster of computers, each computing the results for individual chunks of data. In addition, to do conventional retrieval calculations and producing geophysical products, the Level 2 Configuration File can instruct the software to produce files of simulated radiances based on a state vector formed from a set of geophysical product files taken as input. Combining both the retrieval and simulation tasks in a single piece of software makes it far easier to ensure that identical forward model algorithms and parameters are used in both tasks. This also dramatically reduces the complexity of the code maintenance effort.

Livesey, Nathaniel J.; VanSnyder, Livesey W.; Read, William G.; Schwartz, Michael J.; Lambert, Alyn; Santee, Michelle L.; Nguyen, Honghanh T.; Froidevaux, Lucien; wang, Shuhui; Manney, Gloria L.; Wu, Dong L.; Wagner, Paul A.; Vuu, Christina; Pumphrey, Hugh C.

2011-01-01

162

Sequential Remediation Processes for a Low Level Pesticide Wastewater  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this study was to develop a remediation system for the treatment of a low-level pesticide wastewater that uses available onfarm organic matter as an absorption media, is capable of reducing the concentration of the pesticide to a safe level and is economically viable for implementation by farmers. The absorption capacity of chopped hay and soybean to the fungicide captan was evaluated under batch conditions and the effectiveness of the composting process in depredating captan in contaminated organic materials was evaluated. The results showed that both hay and soybean plant residues were very effective in absorbing 99.2% and 98.5% of captan form the wastewater after 4 hours, respectively. Because of its availability, hay can be used in an onfarm pesticide immobilization system that consists of shallow reinforced concrete pit (filled with hay with steel bars across the top for machinery to roll onto and be washed. The wastewater can be retained for 24 hours which is a sufficient time for hay to absorb the captan. The contaminated hay can then be composted. The addition of used cooking oil raised the temperature of the composting mixture to 63?C. Small reductions in moisture content (from 60% to 58.9 % and C:N ratio (from 30:1 to 28:1 were observed while reductions of 18.92%, 15.56% and 4.8% in the volatile solids, total carbon total Kjeldahl nitrogen were achieved after 10 d of composting, respectively. About 92.4% of the captan was degraded in the first 4 days of composting. Most of captan (92.4% was degraded during the mesophilic stage (first 3 days. The degradation rate constant for the mesophilic stage (0.724 d-1 was 2.74 times the degradation rate constant for the thermophilic stage (0.264 d-1. An onfarm windrow composting process would be very effective in degrading captan contaminated hay. The captan contaminated hay could be mixed with equal amount poultry manure or dairy manure to provide the required bioavailable carbon and nutrients for the composting process. Some used cooking oil could also be added to maintain higher temperature within the compost matrix. The windrows should be mixed on a daily basis to provide sufficient oxygen for the composting microorganisms.

Abdel E. Ghaly

2012-02-01

163

Molecular simulation of dioleoylphosphatidylcholine lipid bilayers at differing levels of hydration.  

OpenAIRE

The structure and dynamics of the lipid and water components of dioleoylphosphatidylcholine bilayers at various levels of hydration were studied using molecular dynamics (MD) simulations. Equilibration of these systems proceeded by use of a hybrid MD and configurational-bias Monte Carlo technique using one atmosphere of pressure normal to the membrane and a set point for the lateral area derived from experimental Bragg spacings, combined with experimentally derived specific volumes for each o...

Mashl, R. J.; Scott, H. L.; Subramaniam, S.; Jakobsson, E.

2001-01-01

164

Optimal values of rovibronic energy levels for triplet electronic states of molecular deuterium  

OpenAIRE

Optimal set of 1050 rovibronic energy levels for 35 triplet electronic states of $D_2$ has been obtained by means of a statistical analysis of all available wavenumbers of triplet-triplet rovibronic transitions studied in emission, absorption, laser and anticrossing spectroscopic experiments of various authors. We used a new method of the analysis (Lavrov, Ryazanov, JETP Letters, 2005), which does not need any \\it a priory \\rm assumptions concerning the molecular structure b...

Lavrov, B. P.; Umrikhin, I. S.

2008-01-01

165

Characterization of Amyloid Structures at the Molecular Level by Solid State Nuclear Magnetic Resonance Spectroscopy  

OpenAIRE

Solid state nuclear magnetic resonance (NMR) spectroscopy is particularly useful in structural studies of amyloid fibrils because solid state NMR techniques have unique capabilities as site-specific, molecular-level structural probes of noncrystalline materials. These techniques provide experimental data that strongly constrain the secondary, tertiary, and quaternary structures of amyloid fibrils, permitting the development of experimentally-based structural models. Examples of techniques tha...

Tycko, Robert

2006-01-01

166

Study on Removal of Organics of Different Molecular Weight by Coagulation-Membrane Filtration Process  

Directory of Open Access Journals (Sweden)

Full Text Available This paper compares the difference in membrane flux between direct membrane filtration and coagulation-membrane filtration, and investigates the removal of organics of different molecular weight by coagulation-membrane filtration process, in turn studies the fouling removal mechanism of coagulation process. The results indicate that for COD removal from raw water, coagulation is effective mainly on the organics of molecular weight higher than 10 kDa, and membrane filtration is effective mainly on the organics of molecular weight between 30 kDa and 100 kDa and higher than 100 kDa; as for UV254 removal, coagulation is effective mainly on the organics of high molecular weight, and membrane filtration is effective mainly on the organics of molecular weight between 1 kDa and 100 kDa. Therefore, it proves that the high molecular organics are mainly responsible for the membrane fouling.

Lin Yang

2010-02-01

167

Biological processes, properties and molecular wiring diagrams of candidate low-penetrance breast cancer susceptibility genes  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Recent advances in whole-genome association studies (WGASs for human cancer risk are beginning to provide the part lists of low-penetrance susceptibility genes. However, statistical analysis in these studies is complicated by the vast number of genetic variants examined and the weak effects observed, as a result of which constraints must be incorporated into the study design and analytical approach. In this scenario, biological attributes beyond the adjusted statistics generally receive little attention and, more importantly, the fundamental biological characteristics of low-penetrance susceptibility genes have yet to be determined. Methods We applied an integrative approach for identifying candidate low-penetrance breast cancer susceptibility genes, their characteristics and molecular networks through the analysis of diverse sources of biological evidence. Results First, examination of the distribution of Gene Ontology terms in ordered WGAS results identified asymmetrical distribution of Cell Communication and Cell Death processes linked to risk. Second, analysis of 11 different types of molecular or functional relationships in genomic and proteomic data sets defined the "omic" properties of candidate genes: i/ differential expression in tumors relative to normal tissue; ii/ somatic genomic copy number changes correlating with gene expression levels; iii/ differentially expressed across age at diagnosis; and iv/ expression changes after BRCA1 perturbation. Finally, network modeling of the effects of variants on germline gene expression showed higher connectivity than expected by chance between novel candidates and with known susceptibility genes, which supports functional relationships and provides mechanistic hypotheses of risk. Conclusion This study proposes that cell communication and cell death are major biological processes perturbed in risk of breast cancer conferred by low-penetrance variants, and defines the common omic properties, molecular interactions and possible functional effects of candidate genes and proteins.

Moreno Víctor

2008-12-01

168

A new vibrational level of the H{sub 2}{sup +} molecular ion  

Energy Technology Data Exchange (ETDEWEB)

A new vibrational level of the molecular ion H{sub 2}{sup +} with binding energy of 1.09 x 10{sup -9} a.u. {approx} 30 neV below the first dissociation limit is predicted, using highly accurate numerical non-relativistic quantum calculations, which go beyond the Born-Oppenheimer approximation. It is the first-excited vibrational level v=1 of the 2p{sigma}{sub u} electronic state, antisymmetric with respect to the exchange of the two protons, with orbital angular momentum L=0. It manifests itself as a huge p - H scattering length of a = 750 {+-} 5 Bohr radii. (authors)

Carbonell, J.; Lazauskas, R. [Institut des Sciences Nucleaires, 38 - Grenoble (France); Delande, D.; Hilico, L.; Kilic, S. [Laboratoire Kastler Brossel, 75 - Paris (France); Kilic, S. [Universite d' Evry Val d' Essonne, 91 - Evry (France)

2003-11-01

169

Molecular imaging with radionuclides, a powerful technique for studying biological processes in vivo  

International Nuclear Information System (INIS)

Our team is carrying on a systematic study devoted to the design of a SPECT detector with submillimeter resolution and adequate sensitivity (1 cps/kBq). Such system will be used for functional imaging of biological processes at molecular level in small animal. The system requirements have been defined by two relevant applications: study of atherosclerotic plaques characterization and stem cells diffusion and homing. In order to minimize costs and implementation time, the gamma detector will be based-as much as possible-on conventional components: scintillator crystal and position sensitive PhotoMultipliers read by individual channel electronics. A coded aperture collimator should be adapted to maximize the efficiency. The optimal selection of the detector components is investigated by systematic use of Monte-Carlo simulations (and laboratory validation tests); and finally preliminary results are presented and discussed here

170

Optimization of Mechanochemical Process of Devulcanisation: Effect of Peptizer Level and Processing Condition  

Science.gov (United States)

The disposal of waste elastomers in particular worn tires represents an environmental problem of global concern. Many attempts have been made to establish technologies for devulcanisation of waste elastomers. This research work investigated the mechanochemical devulcanisation of ground rubber tires (GRT) and studied the stability of sulfidic linkages, which controlled the behavior of the material during processing, at various peptizer level, temperature and rotor speed of a laboratory size internal mixer. Degree of devulcanisation was established by measuring the crosslink density of the GRT before and after the devulcanisation using volume-swelling method. The devulcanized GRT was reprocessed, reshaped and revulcanized in the same manner as virgin rubber. The results showed that the crosslink density of the devulcanized GRT was significantly lower than that of the untreated GRT. The degree of devulcanisation was higher at higher levels of peptizer, lower temperature and rotor speed. It was found that mechanochemical process is a cheap, fast and effective method for devulcanisation of waste tires.

Sangari, Samra

2004-03-01

171

Elevated levels of high-molecular-weight adiponectin in type 1 diabetes  

DEFF Research Database (Denmark)

BACKGROUND: Several studies have shown that type 1 diabetic patients have elevated total levels of the adipocyte-derived adipocytokine adiponectin. However, adiponectin circulates in three different subforms, and the high-molecular-weight (HMW) subform is believed to be the primary biologically active form. The effects of the medium-molecular-weight (MMW) subform and the low-molecular-weight (LMW) subform are still unresolved. PURPOSE: The objective of the study was to investigate the distribution of the three molecular subforms of adiponectin in well-characterized groups of type 1 diabetics with varying degrees of nephropathy as well as in healthy control subjects. STUDY POPULATION: Two hundred seven individuals were included: 58 type 1 diabetics with normoalbuminuria, 46 with microalbuminuria, 46 with macroalbuminuria, and 57 matched controls. METHODS: The HMW, MMW, and LMW subforms were measured using a validated in-house time-resolved immunoflourometric assay after separation by fast protein liquid chromatography. RESULTS: The absolute concentrations of total adiponectin and all subforms were higher in type 1 diabetic patients than healthy controls. However, the relative HMW fraction was up-regulated in type 1 diabetes (P < 0.001), whereas the MMW (P < 0.001) and LMW fractions (P < 0.05) were down-regulated, compared with controls. Accordingly, the increase in concentration of total adiponectin was primarily caused by a major increase of the HMW subform. Levels of total adiponectin and the HMW subform (absolute and relative) were generally unaffected by nephropathy status defined by urinary albumin excretion rate. CONCLUSION: Type 1 diabetes per se is associated with higher adiponectin levels than healthy subjects. This increase is mainly explained by an elevation in the HMW subform. The elevation is unaffected by gender and diabetic kidney disease Udgivelsesdato: 2008/8

Leth, H.; Andersen, K.K.

2008-01-01

172

Atmospheric processes on ice nanoparticles in molecular beams  

OpenAIRE

This review summarizes some recent experiments with ice nanoparticles (large water clusters) in molecular beams and outlines their atmospheric relevance: (1) Investigation of mixed water–nitric acid particles by means of the electron ionization and sodium doping combined with photoionization revealed the prominent role of HNO3 molecule as the condensation nuclei. (2) The uptake of atmospheric molecules by water ice nanoparticles has been studied, and the pickup cross sections for some molec...

MichalFárník

2014-01-01

173

Molecular and genetic diversity in the metastatic process of melanoma.  

Science.gov (United States)

Diversity between metastatic melanoma tumours in individual patients is known; however, the molecular and genetic differences remain unclear. To examine the molecular and genetic differences between metastatic tumours, we performed gene-expression profiling of 63 melanoma tumours obtained from 28 patients (two or three tumours/patient), followed by analysis of their mutational landscape, using targeted deep sequencing of 1697 cancer genes and DNA copy number analysis. Gene-expression signatures revealed discordant phenotypes between tumour lesions within a patient in 50% of the cases. In 18 of 22 patients (where matched normal tissue was available), we found that the multiple lesions within a patient were genetically divergent, with one or more melanoma tumours harbouring 'private' somatic mutations. In one case, the distant subcutaneous metastasis of one patient occurring 3?months after an earlier regional lymph node metastasis had acquired 37 new coding sequence mutations, including mutations in PTEN and CDH1. However, BRAF and NRAS mutations, when present in the first metastasis, were always preserved in subsequent metastases. The patterns of nucleotide substitutions found in this study indicate an influence of UV radiation but possibly also DNA alkylating agents. Our results clearly demonstrate that metastatic melanoma is a molecularly highly heterogeneous disease that continues to progress throughout its clinical course. The private aberrations observed on a background of shared aberrations within a patient provide evidence of continued evolution of individual tumours following divergence from a common parental clone, and might have implications for personalized medicine strategies in melanoma treatment. PMID:24399611

Harbst, Katja; Lauss, Martin; Cirenajwis, Helena; Winter, Christof; Howlin, Jillian; Törngren, Therese; Kvist, Anders; Nodin, Björn; Olsson, Eleonor; Häkkinen, Jari; Jirström, Karin; Staaf, Johan; Lundgren, Lotta; Olsson, Håkan; Ingvar, Christian; Gruvberger-Saal, Sofia K; Saal, Lao H; Jönsson, Göran

2014-05-01

174

Hanford low-level waste process chemistry testing data package  

International Nuclear Information System (INIS)

Recently, the Tri-Party Agreement (TPA) among the State of Washington Department of Ecology, U.S. Department of Energy (DOE) and the US Environmental Protection Agency (EPA) for the cleanup of the Hanford Site was renegotiated. The revised agreement specifies vitrification as the encapsulation technology for low level waste (LLW). A demonstration, testing, and evaluation program underway at Westinghouse Hanford Company to identify the best overall melter-system technology available for vitrification of Hanford Site LLW to meet the TPA milestones. Phase I is a open-quotes proof of principleclose quotes test to demonstrate that a melter system can process a simulated highly alkaline, high nitrate/nitrite content aqueous LLW feed into a glass product of consistent quality. Seven melter vendors were selected for the Phase I evaluation: joule-heated melters from GTS Duratek, Incorporated (GDI); Envitco, Incorporated (EVI); Penberthy Electomelt, Incorporated (PEI); and Vectra Technologies, Incorporated (VTI); a gas-fired cyclone burner from Babcock ampersand Wilcox (BCW); a plasma torch-fired, cupola furnace from Westinghouse Science and Technology Center (WSTC); and an electric arc furnace with top-entering vertical carbon electrodes from the U.S. Bureau of Mines (USBM)

175

Hanford low-level waste process chemistry testing data package  

Energy Technology Data Exchange (ETDEWEB)

Recently, the Tri-Party Agreement (TPA) among the State of Washington Department of Ecology, U.S. Department of Energy (DOE) and the US Environmental Protection Agency (EPA) for the cleanup of the Hanford Site was renegotiated. The revised agreement specifies vitrification as the encapsulation technology for low level waste (LLW). A demonstration, testing, and evaluation program underway at Westinghouse Hanford Company to identify the best overall melter-system technology available for vitrification of Hanford Site LLW to meet the TPA milestones. Phase I is a {open_quotes}proof of principle{close_quotes} test to demonstrate that a melter system can process a simulated highly alkaline, high nitrate/nitrite content aqueous LLW feed into a glass product of consistent quality. Seven melter vendors were selected for the Phase I evaluation: joule-heated melters from GTS Duratek, Incorporated (GDI); Envitco, Incorporated (EVI); Penberthy Electomelt, Incorporated (PEI); and Vectra Technologies, Incorporated (VTI); a gas-fired cyclone burner from Babcock & Wilcox (BCW); a plasma torch-fired, cupola furnace from Westinghouse Science and Technology Center (WSTC); and an electric arc furnace with top-entering vertical carbon electrodes from the U.S. Bureau of Mines (USBM).

Smith, H.D.; Tracey, E.M.; Darab, J.G.; Smith, P.A.

1996-03-01

176

Effects of subchronic exposure to glyphosate in juvenile oysters (Crassostrea gigas): From molecular to individual levels.  

Science.gov (United States)

Glyphosate-based herbicides are extensively used and can be measured in aquatic ecosystems, including coastal waters. The effect of glyphosate on non-target organisms is an issue of worldwide concern. The aim of this study was to investigate the effects of subchronic exposure to glyphosate in juvenile oysters, Crassostrea gigas. Yearling oysters were exposed to three concentrations of glyphosate (0.1, 1 and 100?gL(-1)) for 56days. Various endpoints were studied, from the individual level (e.g., gametogenesis and tissue alterations) to the molecular level (mRNA quantification), including biochemical endpoints such as glutathione-S-transferase (GST) and catalase activities and malondialdehyde content. No mortality and growth occurred during the experiment, and individual biomarkers revealed only slight effects. The levels of gene expression significantly increased in oysters exposed to the highest glyphosate concentration (GST and metallothioneins) or to all concentrations (multi-xenobiotic resistance). These results suggested an activation of defence mechanisms at the molecular level. PMID:25455786

Mottier, Antoine; Séguin, Alexis; Devos, Alexandre; Pabic, Charles Le; Voiseux, Claire; Lebel, Jean Marc; Serpentini, Antoine; Fievet, Bruno; Costil, Katherine

2014-10-30

177

Steered molecular dynamics simulations on the "tail helix latch" hypothesis in the gelsolin activation process.  

OpenAIRE

The molecular basis of the "tail helix latch" hypothesis in the gelsolin activation process has been studied by using the steered molecular dynamics simulations. In the present nanosecond scale simulations, the tail helix of gelsolin was pulled away from the S2 binding surface, and the required forces were calculated, from which the properties of binding between the tail helix and S2 domain and their dynamic unbinding processes were obtained. The force profile provides a detailed rupture mech...

Cheng, Feng; Shen, Jianhua; Luo, Xiaomin; Jiang, Hualiang; Chen, Kaixian

2002-01-01

178

An Investigation of Bacterial Protein Interactions as a Primary Research Project in a Sophomore-Level Molecular Biology Course  

Directory of Open Access Journals (Sweden)

Full Text Available Longer term research activities that may be incorporated in undergraduate courses are a powerful tool for promoting student interest and learning, developing cognitive process skills, and allowing undergraduates to experience real research activities in which they may not otherwise have the opportunity to participate. The challenge to doing so in lower-level courses is that students may have not fully grasped the scientific concepts needed to undertake such research endeavors, and that they may be discouraged if activities are perceived to be too challenging. The paper describes how a bacterial protein:protein interaction detection system was adapted and incorporated into the laboratory component of a sophomore-level Molecular Cell Biology course. The project was designed to address multiple learning objectives connecting course content to the laboratory activities, as well as teach basic molecular biology laboratory skills and procedures in the context of a primary research activity. Pre- and posttesting and student surveys both suggest that the laboratory curriculum resulted in significant learning gains, as well as being well received and valued by the students.?

Jean A. Cardinale

2011-09-01

179

Molecular characterizations of Nop16 in murine mammary tumors with varying levels of c-Myc.  

Science.gov (United States)

NOP16, also known as HSPC111, has been identified as a MYC and estrogen regulated gene in in vitro studies, hence coexpression levels were strongly correlated. Importantly, high expression of NOP16 was associated with poor clinical outcome in breast cancer patients. However, coexpression of NOP16, MYC and estrogen receptor (ESR1) varied widely in tumors and cell lines suggesting that transcriptional regulation differed according to pathological environments. The goal of this study was to determine the expression patterns of Nop16, Myc and Esr1 in murine mammary tumors with disparate histopathological and molecular features. We hypothesized that tumor environments with relatively high Myc levels would have different coexpression patterns than tumor environments with relatively low Myc levels. We measured levels of Myc and Nop16 mRNA and protein in tumors from WAP-c-myc mice that were of high grade and metastasized frequently. In contrast, Myc and Nop16 mRNA and proteins levels were significantly lower in the less aggressive tumors that developed in NRL-TGF? mice. Tumors from both mouse lines express ESR1 protein and we found that Esr1 mRNA levels correlated positively with Myc levels in both models. However, Myc and Nop16 transcript levels correlated positively only in tumors from NRL-TGF? mice. We identified prominent NOP16 protein in nuclei and less prominent staining in the cytoplasm of luminal cells of ducts and lobules from normal mammary glands as well as in hyperplasias and tumors obtained from NRL-TGF? mice. This staining pattern was reversed in tumors from WAP-c-Myc mice as nuclear staining was faint or absent and cytoplasmic staining more pronounced. In summary, the regulation of expression and localization of NOP16 varies in tumor environments with high versus low MYC levels and demonstrate the importance of stratifying clinical breast cancers based on MYC levels. PMID:21863248

Kundel, Donald W; Stromquist, Emily; Greene, Amy L; Zhdankin, Olga; Regal, Ronald R; Rose-Hellekant, Teresa A

2012-04-01

180

Inorganic ion exchange process for partitioning high level commercial waste  

International Nuclear Information System (INIS)

Aspects of the Sandia Solidification Process that pertain to the concept of waste partitioning are covered. The general chemistry of the Sandia Solidification Process is reviewed. Experimental observations that relate to the separation of actinides from rare earths are presented

181

Research accomplishments and seminars of “atomic and molecular process in plasmas (AMPP)” in 2006-2010  

International Nuclear Information System (INIS)

Essential roles of atomic processes of heavy impurity ions and molecular processes in magnetic confinement fusion plasmas have long been recognized. It encouraged efforts of acquiring the spectroscopic and collision data, and had fostered basic studies on the atomic and molecular collisions in each country. Under the auspice of the JSPS-CAS Core-University Program (CUP), we conducted personal exchanges (China ? Japan: 29 persons, and Japan ? China: 18 persons, see Fig. 1) to share the atomic and molecular data and facilitate collaboration on database development. In this report, research accomplishments and seminars on the subject “Atomic and Molecular Process in Plasmas” in the last five years (2006-2010) are summarized. (author)

182

Ultrafast molecular processes mapped by femtosecond x-ray diffraction  

Science.gov (United States)

X-ray diffraction with a femtosecond time resolution allows for mapping photoinduced structural dynamics on the length scale of a chemical bond and in the time domain of atomic and molecular motion. In a pump-probe approach, a femtosecond excitation pulse induces structural changes which are probed by diffracting a femtosecond hard x-ray pulse from the excited sample. The transient angular positions and intensities of diffraction peaks give insight into the momentary atomic or molecular positions and into the distribution of electronic charge density. The simultaneous measurement of changes on different diffraction peaks is essential for determining atom positions and charge density maps with high accuracy. Recent progress in the generation of ultrashort hard x-ray pulses (Cu K?, wavelength ?=0.154 nm) in laser-driven plasma sources has led to the implementation of the powder diffraction and the rotating crystal method with a time resolution of 100 fs. In this contribution, we report new results from powder diffraction studies of molecular materials. A first series of experiments gives evidence of a so far unknown concerted transfer of electrons and protons in ammonium sulfate [(NH4)2SO4], a centrosymmetric structure. Charge transfer from the sulfate groups results in the sub-100 fs generation of a confined electron channel along the c-axis of the unit cell which is stabilized by transferring protons from the adjacent ammonium groups into the channel. Time-dependent charge density maps display a periodic modulation of the channel's charge density by low-frequency lattice motions with a concerted electron and proton motion between the channel and the initial proton binding site. A second study addresses atomic rearrangements and charge dislocations in the non-centrosymmetric potassium dihydrogen phosphate [KH2PO4, KDP]. Photoexcitation generates coherent low-frequency motions along the LO and TO phonon coordinates, leaving the average atomic positions unchanged. The time-dependent maps of electron density demonstrate a concomitant oscillatory relocation of electronic charge with a spatial amplitude of the order of a chemical bond length, two orders of magnitude larger than the vibrational amplitudes. The coherent phonon motions drive the charge relocation, similar to a soft mode driven phase transition between the ferro- and paraelectric phase of KDP.

Elsaesser, Thomas

2012-02-01

183

Molecular level studies on binding modes of labeling molecules with polyalanine peptides  

Science.gov (United States)

In this work, the binding modes of typical labeling molecules (thioflavin T (ThT), Congo red (CR) and copper(ii) phthalocyanine tetrasulfonic acid tetrasodium salt (PcCu(SO3Na)4)) on pentaalanine, which is a model peptide segment of amyloid peptides, have been resolved at the molecular level by using scanning tunneling microscopy (STM). In the STM images, ThT molecules are predominantly adsorbed parallel to the peptide strands and two binding modes could be identified. It was found that ThT molecules are preferentially binding on top of the peptide strand, and the mode of intercalated between neighboring peptides also exists. The parallel binding mode of CR molecules can be observed with pentaalanine peptides. Besides the binding modes of labeling molecules, the CR and PcCu(SO3Na)4 display different adsorption affinity with the pentaalanine peptides. The results could be beneficial for obtaining molecular level insight of the interactions between labeling molecules and peptides.In this work, the binding modes of typical labeling molecules (thioflavin T (ThT), Congo red (CR) and copper(ii) phthalocyanine tetrasulfonic acid tetrasodium salt (PcCu(SO3Na)4)) on pentaalanine, which is a model peptide segment of amyloid peptides, have been resolved at the molecular level by using scanning tunneling microscopy (STM). In the STM images, ThT molecules are predominantly adsorbed parallel to the peptide strands and two binding modes could be identified. It was found that ThT molecules are preferentially binding on top of the peptide strand, and the mode of intercalated between neighboring peptides also exists. The parallel binding mode of CR molecules can be observed with pentaalanine peptides. Besides the binding modes of labeling molecules, the CR and PcCu(SO3Na)4 display different adsorption affinity with the pentaalanine peptides. The results could be beneficial for obtaining molecular level insight of the interactions between labeling molecules and peptides. Electronic supplementary information (ESI) available. See DOI: 10.1039/c0nr00782j

Mao, Xiaobo; Wang, Chenxuan; Ma, Xiaojing; Zhang, Min; Liu, Lei; Zhang, Lan; Niu, Lin; Zeng, Qindao; Yang, Yanlian; Wang, Chen

2011-04-01

184

Determination of molecular-level structural information of uranium in environmentally relevant samples by EXAFS  

International Nuclear Information System (INIS)

Synchrotron-based extended X-ray absorption fine structure (EXAFS) spectroscopy is a powerful technique to study many chemical elements in different states of aggregation. Informations can be obtained on the speciation and the complexation behavior of radionuclides in solutions, the adsorption of radionuclides on mineral or biological surfaces. The obtained structural parameters give molecular-level structural information from ligands surrounding a central radionuclide ion. The results can be used as an input for existing adsorption models, which can describe the migration of radionuclides in the geosphere. The EXAFS experiments we are carried out at SSRL in Stanford (USA) and at HASYLAB in Hamburg (Germany). (orig.)

185

Protein Molecular Structures, Protein SubFractions, and Protein Availability Affected by Heat Processing: A Review  

Directory of Open Access Journals (Sweden)

Full Text Available The utilization and availability of protein depended on the types of protein and their specific susceptibility to enzymatic hydrolysis (inhibitory activities in the gastrointestine and was highly associated with protein molecular structures. Studying internal protein structure and protein subfraction profiles leaded to an understanding of the components that make up a whole protein. An understanding of the molecular structure of the whole protein was often vital to understanding its digestive behavior and nutritive value in animals. In this review, recently obtained information on protein molecular structural effects of heat processing was reviewed, in relation to protein characteristics affecting digestive behavior and nutrient utilization and availability. The emphasis of this review was on (1 using the newly advanced synchrotron technology (S-FTIR as a novel approach to reveal protein molecular chemistry affected by heat processing within intact plant tissues; (2 revealing the effects of heat processing on the profile changes of protein subfractions associated with digestive behaviors and kinetics manipulated by heat processing; (3 prediction of the changes of protein availability and supply after heat processing, using the advanced DVE/OEB and NRC-2001 models, and (4 obtaining information on optimal processing conditions of protein as intestinal protein source to achieve target values for potential high net absorbable protein in the small intestine. The information described in this article may give better insight in the mechanisms involved and the intrinsic protein molecular structural changes occurring upon processing.

Peiqiang Yu

2007-01-01

186

Effects of stimulus type and level repetition on content-level binding in global/local processing  

Directory of Open Access Journals (Sweden)

Full Text Available The processing and representation of hierarchical objects not only involves the identification of information at the different levels, but also the binding of the identified content to its respective level. Whereas identification is well understood, little is known about content-level binding. In a recent study, however, it has been shown that attentional priming of certain spatial frequencies is advantageous for this binding. Therefore, the present study investigated effects of related factors on the binding process, namely stimulus type (filled or outlined hierarchical letters, stimulus-type repetition, and target-level repetition. The results show that content-level binding was improved for outlined stimuli and after target-level repetition, whereas stimulus-type repetition had no effect. The data suggest that hierarchical stimuli are mentally represented by abstract level categories and that content is linked to these categories by means of level-specific and identity-specific spatial-frequency information.

RonaldHübner

2011-06-01

187

Wood–water interactions : Linking molecular level mechanisms with macroscopic performance  

DEFF Research Database (Denmark)

Predicting the performance of wood for decades ahead is important when using the material for structural purposes. The performance is closely related to the hierarchical material structure of wood and the dependent interaction with water in the structure. Accurately predicting wood performance therefore requires an understanding of material structure from molecular to macroscopic level as well as of the impact of water molecules. The objective of this work is to investigate the performance of wood in terms of mechanical response of the material and effect of water. To understand the latter, one must first know in which parts of the wood structure, water is located. If parts of the water in wood are held in capillaries in the wood structure, these water molecules interact with the material differently than those held within wood cell walls. In this study, the occurrence of capillary water in wood is investigated at high levels of relative humidity (RH), where capillary water might be present. Three different techniques are employed in overlapping RH regimes. The three techniques give similar results and show that the amount of capillary water is insignificant up to at least 99.5 % RH. Thus, for wood in equilibrium with surrounding climate in the RH range 0-99.5 %, water is only significantly present within cell walls. A structural model of a wood cell is developed in this study using Finite Element Method for predicting the mechanical performance of wood. The starting point for the model is the physical behaviour on the molecular level since water interferes with wood at this level. The elastic material properties of the wood cell wall are explained by the organisation of wood constituents and their properties. The effect of water as well as temperature is incorporated by considering the amount of hydrogen bonds between wood constituents and the stiffness of these bonds. The mechanical response of wood includes a substantial time-dependent response, which previously has been explained by sliding between wood constituents on the molecular level. In this study, this is incorporated in the model as time-dependent shearing of the material planes of the cell wall. The calculated results of the model is verified against various experimental results from literature as well as from measurements presented in this work. It is shown that the structural model is able to describe a diverse range of mechanical responses of wood cells in both elastic and time-dependent domains. Furthermore, comparison of results from experiments and model suggests that the mechanical response of wood tissue, i.e. the hierarchical level above single wood cells, is a sum of responses from both wood cells and intercellular layer, i.e. the middle lamella.

Engelund, Emil Tang

2011-01-01

188

Molecular-Level Transformations of Lignin During Photo-Oxidation and Biodegradation  

Science.gov (United States)

As the second most abundant component of terrestrial plant residues, lignin plays a key role in regulating plant litter decomposition, humic substance formation, and dissolved organic matter (OM) production from terrestrial sources. Biodegradation is the primary decomposition process of lignin on land. However, photo- oxidation of lignin-derived compounds has been reported in aquatic systems and is considered to play a vital role in arid and semiarid regions. With increasing ultraviolet (UV) radiation due to ozone depletion, it is important to understand the biogeochemical fate of lignin exposed to photo-oxidation in terrestrial environments. This study examines and compares the transformation of lignin in a three-month laboratory simulation of biodegradation and photo-oxidation using molecular-level techniques. Lignin-derived monomers extracted by copper oxidation were analyzed by gas chromatography/mass spectrometry (GC/MS) from the water-soluble and insoluble OM of 13C-labeled corn leaves. Biodegradation increased the solubility of lignin monomers in comparison to the control samples, and the acid-to-aldehyde (Ad/Al) ratios increased in both the water-soluble and insoluble OM, indicating a higher degree of side-chain lignin oxidation. Photo-oxidation did not produce a significant change on the solubility or Ad/Al ratios of lignin from corn leaves. However, the ratios of trans-to-cis isomers of both cinnamyl units (p-coumaric acid and ferulic acid) increased with photo-oxidation and decreased with biodegradation in the insoluble OM. We also investigated the role of photo-oxidation in lignin transformation in soils cropped with 13C-labeled corn. Interestingly, the organic carbon content increased significantly with time in the water-soluble OM from soil/corn residues under UV radiation. An increase in the concentration of lignin monomers and dimers and the Ad/Al ratios was also observed with photo-oxidation. Iso-branched fatty acids of microbial origin remained in a similar concentration in the water-soluble OM from the UV-radiated and control soils, indicating little microbial contribution to the observed increase in water-soluble carbon. These observations suggest that photo-oxidation may increase the solubility of soil organic matter (SOM) through the oxidation of lignin-derived compounds. Mechanisms of lignin oxidation (demethylation or side-chain oxidation) and molecular size distribution changes of the water-soluble and NaOH-soluble OM during photo-oxidation and biodegradation will also be examined using solution-state nuclear magnetic resonance (NMR) spectroscopy. Collectively, our experiment demonstrates that while biodegradation predominates in the decomposition of lignin in plant litter, photo- oxidation may play an important part in destabilizing lignin-derived compounds in the soil.

Feng, X.; Hills, K.; Simpson, A. J.; Simpson, M. J.

2009-05-01

189

Data processing for structure allocation of molecular C2HD  

International Nuclear Information System (INIS)

Acetylene (C2H2) is a linear quadratic molecule and an example of C - C with triple band in chemistry that The structure of acetylene molecule has 7 normal vibrational modes. Rovibrational absorption spectrum in the IR region of this molecule is detected in the outer atmosphere of the earth. It plays an important role in intermolecular studies. this molecular is include two important iso toper 12C2,HD12C2D2 that in this paper we study on l000cm-1 to l0000cm-1 for the isotope C2HD. Energy expansion coefficients for series of stretch vibration bands of some combination tones is calculated and approximated. At the end, the study of prediction of intensity and comparison to experimental intensity is done too In this paper we try to describe our experimental or theoretical results.

190

Atmospheric processes on ice nanoparticles in molecular beams  

Science.gov (United States)

This review summarizes some recent experiments with ice nanoparticles (large water clusters) in molecular beams and outlines their atmospheric relevance: (1) Investigation of mixed water–nitric acid particles by means of the electron ionization and sodium doping combined with photoionization revealed the prominent role of HNO3 molecule as the condensation nuclei. (2) The uptake of atmospheric molecules by water ice nanoparticles has been studied, and the pickup cross sections for some molecules exceed significantly the geometrical sizes of the ice nanoparticles. (3) Photodissociation of hydrogen halides on water ice particles has been shown to proceed via excitation of acidically dissociated ion pair and subsequent biradical generation and H3O dissociation. The photodissociation of CF2Cl2 molecule in clusters is also mentioned. Possible atmospheric consequences of all these results are briefly discussed.

Fárník, Michal; Poterya, Viktoriya

2014-02-01

191

Atmospheric processes on ice nanoparticles in molecular beams  

Directory of Open Access Journals (Sweden)

Full Text Available This review summarizes some recent experiments with ice nanoparticles (large water clusters in molecular beams and outlines their atmospheric relevance: (1 Investigation of mixed water–nitric acid particles by means of the electron ionization and sodium doping combined with photoionization revealed the prominent role of HNO3 molecule as the condensation nuclei. (2 The uptake of atmospheric molecules by water ice nanoparticles has been studied, and the pickup cross sections for some molecules exceed significantly the geometrical sizes of the ice nanoparticles. (3 Photodissociation of hydrogen halides on water ice particles has been shown to proceed via excitation of acidically dissociated ion pair and subsequent biradical generation and H3O dissociation. The photodissociation of CF2Cl2 molecule in clusters is also mentioned. Possible atmospheric consequences of all these results are briefly discussed.

MichalFárník

2014-02-01

192

Molecular Specificity of Multiple Hippocampal Processes Governing Fear Extinction  

OpenAIRE

Over many years, fear extinction has been conceptualized as one dominant process, new inhibitory learning, which serves to dampen previously acquired fear. Here we present an alternative view, that brain region-specific processing of representations, expectations and emotional attributes of the fear-provoking event, recruits unique mechanisms that interdependently contribute to the conditioning and extinction of fear. The co-occurrence of these mechanisms within the fear circuit can thus be t...

Radulovic, Jelena; Tronson, Natalie C.

2010-01-01

193

TRUEX process applied to radioactive Idaho Chemical Processing Plant high-level waste calcine  

International Nuclear Information System (INIS)

Equal volume batch contact experiments were performed with dissolved, radioactive high-level waste (HLW) calcine and the TRansUranic EXtraction (TRUEX) process solvent. Extraction, scrub, and strip distribution coefficients (D) were obtained for the transuranic (TRU) elements in order to evaluate the efficiency of the TRUEX process in treating this waste. The extraction, scrub, and strip behavior of other elements, such as chromium, zirconium, and technetium, was also observed. A TRU alpha decontamination factor of >10,000 was achieved; after three extraction batch contacts TRU alpha activity was reduced from 1,420 nCi/g to 0.02 nCi/g. Dilute nitric acid was used to scrub extracted acid, zirconium, and iron from the solvent prior to stripping. Dilute 1-hydroxyethane, 1-1, diphosphonic acid (HEDPA) was used as a gross TRU stripping reagent to recover the extracted TRUs. Data from these batch contact experiments were used to develop a counter-current flowsheet for TRU removal using the Generic TRUEX Model (GTM). Process improvements and optimizations of the flowsheet have been evaluated using a non-radioactive dissolved calcine simulant spiked with tracers to obtain additional distribution coefficient data. These data were used in the GTM to refine the flowsheet. The flowsheet was then evaluated using a counter-current 5.5 cm centrifugal contactor pilot plant with a non-radioactive dissolved calcine simulant. The experiments involving radioactive waste provided crucial data for developing a baseline TRUEX process flowsheet which can effectively separate TRU components from ICPP high-level waste

194

Molecular orbital state due to halo neutrons in heavy ion nuclear reaction and its resonance level  

International Nuclear Information System (INIS)

For the systems involving weakly bound, exotic nuclei, the distinctive features of CRC effects are expected, and the formation of nucleonic molecular orbitals may become the dominant effect. The energy level spacing of weakly bound nucleon states may be much smaller, and furthermore, the tails of wave functions extend to far outside the core nuclei. In 11Be + 10Be system, the radioactive nuclei 11Be have two weakly bound valence neutron states (halo states). The neutron wave functions in the states of 11Be extend to far outside the nuclei for the weakly bound states and for the sharp resonance state, respectively. Moreover, the energy spacing of these states is very small. The core excitation energy of 10Be is much higher than the Coulomb barrier. The CRC calculation and the molecular orbital analysis for this system by employing the channels of 11Be states were carried out. The procedure is explained. The results are shown, and the sharp rise and big enhancement of the subbarrier fusion cross section of the CRC calculation were observed. Such CRC effects reflect the formation of a covalent molecular orbital. The behavior of the fine structure depends on the choice of parameters of the bare potential. (K.I.)

195

Process for solidifying high-level nuclear waste  

International Nuclear Information System (INIS)

The addition of a small amount of reducing agent to a mixture of a high-level radioactive waste calcine and glass frit before the mixture is melted will produce a more homogeneous glass which is leach-resistant and suitable for long-term storage of high-level radioactive waste products

196

Optimal values of rovibronic energy levels for triplet electronic states of molecular deuterium  

International Nuclear Information System (INIS)

An optimal set of 1050 rovibronic energy levels for 35 triplet electronic states of D2 has been obtained by means of a statistical analysis of all available wavenumbers of triplet-triplet rovibronic transitions studied in emission, absorption, laser and anticrossing spectroscopic experiments of various authors. We used a new method of analysis (Lavrov and Ryazanov 2005 JETP Lett. 81 371-4), which does not need any a priori assumptions concerning the molecular structure, being based on only two fundamental principles: Rydberg-Ritz and maximum likelihood. The method provides the opportunity to obtain the root-mean-square estimates for uncertainties of the experimental wavenumbers independent from those presented in the original papers. A total of 234 from 3822 published wavenumber values were found to be spurious, while the remaining set of the data may be divided into 20 subsets (samples) of uniformly precise data having close to normal distributions of random errors within the samples. New experimental wavenumber values of 125 questionable lines were obtained in the present work. Optimal values of the rovibronic levels were obtained from the experimental data set consisting of 3713 wavenumber values (3588 old and 125 new). The unknown shift between levels of ortho- and para-deuterium was found by least-squares analysis of the a3?+g, v = 0, N = 0 to 18 rovibronic levels with odd and even values of N. All the energy levels weven values of N. All the energy levels were obtained relative to the lowest vibro-rotational level (v = 0, N = 0) of the a3?+g electronic state, and presented in tabular form together with the standard deviations of the empirical determination. New energy-level values differ significantly from those available in the literature

197

High-level waste processing and conditioning: vitrification  

International Nuclear Information System (INIS)

The vitrification process used to treat fission product solutions at the Marcoule Vitrification Plant is described. The type of waste processed is characterized by its very high activity and the long lifetimes of some of the emitters that it contains. The performance obtained with this process is given together with the future developments envisaged. The storage of glasses is described as well as their behavior with time

198

Rovibrational coupling in molecular nitrogen at high temperature: An atomic-level study  

Science.gov (United States)

This article contains an atomic-level numerical investigation of rovibrational relaxation in molecular nitrogen at high temperature (>4000 K), neglecting dissociation. We conduct our study with the use of pure Molecular Dynamics (MD) and Classical Trajectory Calculations (CTC) Direct Simulation Monte Carlo (DSMC), verified to produce statistically identical results at the conditions of interest here. MD and CTC DSMC solely rely on the specification of a potential energy surface: in this work, the site-site Ling-Rigby potential. Additionally, dissociation is prevented by modeling the N-N bond either as a harmonic or an anharmonic spring. The selected molecular model was shown to (i) recover the shear viscosity (obtained from equilibrium pure MD Green-Kubo calculations) of molecular nitrogen over a wide range of temperatures, up to dissociation; (ii) predict well the near-equilibrium rotational relaxation behavior of N2; (iii) reproduce vibrational relaxation times in excellent accordance with the Millikan-White correlation and previous semi-classical trajectory calculations in the low temperature range, i.e., between 4000 K and 10 000 K. By simulating isothermal relaxations in a periodic box, we found that the traditional two-temperature model assumptions become invalid at high temperatures (>10 000 K), due to a significant coupling between rotational and vibrational modes for bound states. This led us to add a modification to both the Jeans and the Landau-Teller equations to include a coupling term, essentially described by an additional relaxation time for internal energy equilibration. The degree of anharmonicity of the N2 bond determines the strength of the rovibrational coupling. Although neglecting N2 dissociation only provides a partial description of a nitrogen system at very high temperatures, high-energy trends for bound-bound transitions are essential to understand nonequilibrium gas flows, with possible implications on rovibration/chemistry interaction at the onset of N2 dissociation.

Valentini, Paolo; Norman, Paul; Zhang, Chonglin; Schwartzentruber, Thomas E.

2014-05-01

199

Rovibrational coupling in molecular nitrogen at high temperature: An atomic-level study  

Energy Technology Data Exchange (ETDEWEB)

This article contains an atomic-level numerical investigation of rovibrational relaxation in molecular nitrogen at high temperature (>4000 K), neglecting dissociation. We conduct our study with the use of pure Molecular Dynamics (MD) and Classical Trajectory Calculations (CTC) Direct Simulation Monte Carlo (DSMC), verified to produce statistically identical results at the conditions of interest here. MD and CTC DSMC solely rely on the specification of a potential energy surface: in this work, the site-site Ling-Rigby potential. Additionally, dissociation is prevented by modeling the N–N bond either as a harmonic or an anharmonic spring. The selected molecular model was shown to (i) recover the shear viscosity (obtained from equilibrium pure MD Green-Kubo calculations) of molecular nitrogen over a wide range of temperatures, up to dissociation; (ii) predict well the near-equilibrium rotational relaxation behavior of N{sub 2}; (iii) reproduce vibrational relaxation times in excellent accordance with the Millikan-White correlation and previous semi-classical trajectory calculations in the low temperature range, i.e., between 4000 K and 10?000 K. By simulating isothermal relaxations in a periodic box, we found that the traditional two-temperature model assumptions become invalid at high temperatures (>10?000 K), due to a significant coupling between rotational and vibrational modes for bound states. This led us to add a modification to both the Jeans and the Landau-Teller equations to include a coupling term, essentially described by an additional relaxation time for internal energy equilibration. The degree of anharmonicity of the N{sub 2} bond determines the strength of the rovibrational coupling. Although neglecting N{sub 2} dissociation only provides a partial description of a nitrogen system at very high temperatures, high-energy trends for bound-bound transitions are essential to understand nonequilibrium gas flows, with possible implications on rovibration/chemistry interaction at the onset of N{sub 2} dissociation.

Valentini, Paolo, E-mail: vale0142@umn.edu; Norman, Paul, E-mail: norma198@umn.edu; Zhang, Chonglin, E-mail: zhang993@umn.edu; Schwartzentruber, Thomas E., E-mail: schwart@aem.umn.edu [Department of Aerospace Engineering and Mechanics, College of Science and Engineering, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

2014-05-15

200

Renormalization of Molecular Quasiparticle Levels at Metal-Molecule Interfaces: Trends across Binding Regimes  

DEFF Research Database (Denmark)

When an electron or a hole is added into an orbital of an adsorbed molecule the substrate electrons will rearrange in order to screen the added charge. This polarization effect reduces the electron addition and removal energies of the adsorbed molecule relative to those of the free molecule. Using a microscopic model of the metal-molecule interface, we illustrate the basic features of this renormalization mechanism through systematic GW, Hartree-Fock, and Kohn-Sham calculations for the molecular energy levels as function of the model parameters. We identify two different polarization mechanisms: (i) polarization of the metal (image charge formation) and (ii) polarization of the molecule via charge transfer across the interface. The importance of (i) and (ii) is found to increase with the metal density of states at the Fermi level and metal-molecule coupling strength, respectively.

Thygesen, Kristian Sommer; Rubio, Angel

2009-01-01

201

Investigating the effect of molecular doping on the energy levels using Seebeck measurements  

Energy Technology Data Exchange (ETDEWEB)

Molecular doping plays an essential role in small molecule based organic devices like solar cells or light-emitting diodes, because it allows to control the Fermi level in the doped layers with the corresponding advantages. However the exact mechanisms of molecular doping are still far from being fully understood. We investigate the influence of doping in different material combinations of dopants and host materials. Seebeck measurements are used to study the energetic distance between Fermi energy and transport level of doped charge transport materials, e.g. fullerene C{sub 60} or N,N,N',N'-Tetrakis(4-methoxyphenyl)-benzidine (MeO-TPD). For n-doping of C{sub 60} a novel airstable dopant is presented. For MeO-TPD and C60 a shift of the energetic distances from 180 meV down to 30 meV and from 120 meV down to 25 meV, respectively, is observed when increasing the doping concentration. Furthermore the influence of the temperature on conductivity and Seebeck measurements is shown. For MeO-TPD and C{sub 60} the activation energies of the conductivity are found to shift from 310 meV down to 210 meV and from 240 meV down to 60 meV, respectively, with increased doping concentration.

Menke, Torben; Leo, Karl; Riede, Moritz [Institut fuer Angewandte Photophysik (IAPP), TU Dresden, 01062 Dresden (Germany); Wei, Peng; Bao, Zhenan [Stanford University, CA 94305 (United States)

2011-07-01

202

Physiological and molecular level effects of silver nanoparticles exposure in rice (Oryza sativa L.) seedlings.  

Science.gov (United States)

The physiological and molecular level changes of silver nanoparticles (AgNPs) exposure were investigated in rice (Oryza sativa L.) seedlings. The seedlings were exposed to different concentrations of (0, 0.2, 0.5 and 1 mg L(-1)) AgNPs for one week. Significant reduction in root elongation, shoot and root fresh weights, total chlorophyll and carotenoids contents were observed. Exposure to 0.5 and 1 mg L(-1) of AgNPs caused significant increase in hydrogen peroxide formation and lipid peroxidation in shoots and roots, increased foliar proline accumulation and decreased sugar contents. AgNPs exposure resulted in a dose dependant increase in reactive oxygen species generation and also caused cytotoxicity as evidenced by increased dihydroethidium, 3'-(p-hydroxyphenyl) fluorescein and propidium iodide fluorescence. Tetramethylrhodamine methyl ester assay showed decreased mitochondrial membrane potential with increasing concentrations of AgNPs exposure in roots. Real Time PCR analysis showed differential transcription of genes related to oxidative stress tolerance viz. FSD1, MSD1, CSD1, CSD2, CATa, CATb, CATc, APXa and APXb in shoots and roots of rice seedlings. The overall results suggest that exposure to AgNPs caused significant physiological and molecular level changes, oxidative stress and also resulted in the induction oxidative stress tolerance mechanisms in rice seedlings. PMID:25048895

Nair, Prakash M Gopalakrishnan; Chung, Ill Min

2014-10-01

203

Proposed methods for treating high-level pyrochemical process wastes  

International Nuclear Information System (INIS)

This survey illustrates the large variety and number of possible techniques available for treating pyrochemical wastes; there are undoubtedly other process types and many variations. The choice of a suitable process is complicated by the uncertainty as to what will be an acceptable waste form in the future for both TRU and non-TRU wastes

204

Managing and Organizing Concurrent Processes According to the CMM Levels  

OpenAIRE

Abstract Research for reduced lead time and cost in concurrent process development (CPD) becomes crucial in new work organizations. Today, the concurrent processes involve more and more activities and work groups which must be efficiently coordinated. In this article, the authors propose a framework for structuring concurrent activities in order to improve the global performance (lead time, workload, risks,...

David, Michael; Idelmerfaa, Zahra; Richard, Jacques

2005-01-01

205

Study on Removal of Organics of Different Molecular Weight by Coagulation-Membrane Filtration Process  

OpenAIRE

This paper compares the difference in membrane flux between direct membrane filtration and coagulation-membrane filtration, and investigates the removal of organics of different molecular weight by coagulation-membrane filtration process, in turn studies the fouling removal mechanism of coagulation process. ...

Lin Yang; Bin Sun; Weiping Huang

2010-01-01

206

New alternatives for processing low and medium level liquid wastes  

International Nuclear Information System (INIS)

After a brief presentation of the actual scheme for low-level and intermediate-level radioactive liquid waste treatment in the new reprocessing plant of ''La Hague'', the new trends in ResdArch and Development studies are presented. In a first step, the total amount of low-level and intermediate-level wastes could be concentrated by distillation, with disposal of condensates. Concentrates, prior to conditioning, could be treated by chemical precipitation or by mineral ion exchangers. The saline solution, then free of ? and ?? major radionuclides could be immobilized in bitumen and sent for disposal in surface storage conditions. The solid residual fraction, sludges or saturated ion exchangdRs, could be converted to oxides and sintered for deep geological disposal

207

Mean level signal crossing rate for an arbitrary stochastic process  

DEFF Research Database (Denmark)

The issue of the mean signal level crossing rate for various probability density functions with primary relevance for optics is discussed based on a new analytical method. This method relies on a unique transformation that transforms the probability distribution under investigation into a normal probability distribution, for which the distribution of mean level crossings is known. In general, the analytical results for the mean level crossing rate are supported and confirmed by numerical simulations. In particular, we illustrate the present method by presenting analytic expressions for the mean level crossing rate for various probability distributions, including ones that previously were unavailable, such as the uniform, the so-called gamma-gamma, and the Rice–Nakagami distribution. However, in a limited number of cases the present results differ somewhat from the result reported in the literature. At present, this discrepancy remains unexplained and is laid open for future discussion.

Yura, Harold T.; Hanson, Steen Grüner

2010-01-01

208

Molecular processes in a high temperature shock layer  

Science.gov (United States)

Research was completed on several aspects of dissociative recombination (DR) for the molecules NO(+), N2(+), and O2(+). For O2(+), DR with an electron is described by, O2(+) + e(-) yields O + O. Model studies were completed of the windows arising in DR cross section from excited ion vibrational levels and of the variation of the DR cross section with the intersection point of the ion and neutral dissociative state potential curves.

Guberman, Steven L.

1987-01-01

209

Stochastic dynamics of small ensembles of non-processive molecular motors: the parallel cluster model  

CERN Document Server

Non-processive molecular motors have to work together in ensembles in order to generate appreciable levels of force or movement. In skeletal muscle, for example, hundreds of myosin II molecules cooperate in thick filaments. In non-muscle cells, by contrast, small groups with few tens of non-muscle myosin II motors contribute to essential cellular processes such as transport, shape changes or mechanosensing. Here we introduce a detailed and analytically tractable model for this important situation. Using a three-state crossbridge model for the myosin II motor cycle and exploiting the assumptions of fast power stroke kinetics and equal load sharing between motors in equivalent states, we reduce the stochastic reaction network to a one-step master equation for the binding and unbinding dynamics (parallel cluster model) and derive the rules for ensemble movement. We find that for constant external load, ensemble dynamics is strongly shaped by the catch bond character of myosin II, which leads to an increase of th...

Erdmann, Thorsten; Schwarz, Ulrich S

2013-01-01

210

Optimal values of rovibronic energy levels for triplet electronic states of molecular deuterium  

Science.gov (United States)

An optimal set of 1050 rovibronic energy levels for 35 triplet electronic states of D2 has been obtained by means of a statistical analysis of all available wavenumbers of triplet-triplet rovibronic transitions studied in emission, absorption, laser and anticrossing spectroscopic experiments of various authors. We used a new method of analysis (Lavrov and Ryazanov 2005 JETP Lett. 81 371-4), which does not need any a priori assumptions concerning the molecular structure, being based on only two fundamental principles: Rydberg-Ritz and maximum likelihood. The method provides the opportunity to obtain the root-mean-square estimates for uncertainties of the experimental wavenumbers independent from those presented in the original papers. A total of 234 from 3822 published wavenumber values were found to be spurious, while the remaining set of the data may be divided into 20 subsets (samples) of uniformly precise data having close to normal distributions of random errors within the samples. New experimental wavenumber values of 125 questionable lines were obtained in the present work. Optimal values of the rovibronic levels were obtained from the experimental data set consisting of 3713 wavenumber values (3588 old and 125 new). The unknown shift between levels of ortho- and para-deuterium was found by least-squares analysis of the a3?+g, v = 0, N = 0 ÷ 18 rovibronic levels with odd and even values of N. All the energy levels were obtained relative to the lowest vibro-rotational level (v = 0, N = 0) of the a3?+g electronic state, and presented in tabular form together with the standard deviations of the empirical determination. New energy-level values differ significantly from those available in the literature.

Lavrov, B. P.; Umrikhin, I. S.

2008-05-01

211

Optimal values of rovibronic energy levels for triplet electronic states of molecular deuterium  

Energy Technology Data Exchange (ETDEWEB)

An optimal set of 1050 rovibronic energy levels for 35 triplet electronic states of D{sub 2} has been obtained by means of a statistical analysis of all available wavenumbers of triplet-triplet rovibronic transitions studied in emission, absorption, laser and anticrossing spectroscopic experiments of various authors. We used a new method of analysis (Lavrov and Ryazanov 2005 JETP Lett. 81 371-4), which does not need any a priori assumptions concerning the molecular structure, being based on only two fundamental principles: Rydberg-Ritz and maximum likelihood. The method provides the opportunity to obtain the root-mean-square estimates for uncertainties of the experimental wavenumbers independent from those presented in the original papers. A total of 234 from 3822 published wavenumber values were found to be spurious, while the remaining set of the data may be divided into 20 subsets (samples) of uniformly precise data having close to normal distributions of random errors within the samples. New experimental wavenumber values of 125 questionable lines were obtained in the present work. Optimal values of the rovibronic levels were obtained from the experimental data set consisting of 3713 wavenumber values (3588 old and 125 new). The unknown shift between levels of ortho- and para-deuterium was found by least-squares analysis of the a{sup 3}{sigma}{sup +}{sub g}, v = 0, N = 0 to 18 rovibronic levels with odd and even values of N. All the energy levels were obtained relative to the lowest vibro-rotational level (v = 0, N = 0) of the a{sup 3}{sigma}{sup +}{sub g} electronic state, and presented in tabular form together with the standard deviations of the empirical determination. New energy-level values differ significantly from those available in the literature.

Lavrov, B P; Umrikhin, I S [Faculty of Physics, St Petersburg State University, St Petersburg 198504 (Russian Federation)], E-mail: lavrov@pobox.spbu.ru

2008-05-28

212

Low-level radioactive waste regulatory constraints affecting radwaste processing  

International Nuclear Information System (INIS)

Utilities frequently find that regulatory constraints strongly affect their choice of technology for processing LLRW from nuclear power plants. It is the purpose of the present study to identify such constraints and assess their impact on utilities' LLRW processing choices. The term regulatory constraint is used in this report to encompass regulations, rules, and procedures that effectively control any or all phases of LLRW managerial activity. These constraints may be issued by agencies of federal, state, or local governments, and, in some cases, non-governmental organizations. The phases of LLRW to which these constraints may be addressed are disposal, processing (including effluent control), storage and transportation

213

Studies on liposomes with Chlorophyll for monitoring the electromagnetic influence at molecular level  

International Nuclear Information System (INIS)

The liposomes with Chlorophyll are excellent model membranes and could be successfully used to study the electromagnetic influence at molecular level. The strong visible absorption and fluorescence of Chlorophyll allow its use as sensor for the interactions at molecular level and as a fluorescence marker; it reflects certain aspects of the supramolecular structure of the lipid phase: fluidity, lipid and liposomes aggregation. The objective of our work was to evidence athermal effect of low level, pulsed microwave (MW) fields on liposomes and to evidence the possible mechanism of interaction at molecular level. Unilamellar liposomes were obtained from multilamellar vesicles by the hand-shaken method and sonication for 30 minutes. The multilamellar vesicles were prepared using Chla /lipid films with specific molar ratio (lipid/Chla 1/10 and 1/100) and different lipids (Dipalmitoyl phosphatidylcholine, Dimirystoyl Phosphatidylcholine and Dioleoyl Phosphatidylcholine-Sigma). The films were dispersed in buffer solutions of different pH (6.2 - 7.6). The Chlorophyll was freshly extracted from spinach leaves and separated by the chromatographic method. Portions of liposome suspension (0.6 ml) were inserted into Teflon cuvettes. The samples were irradiated in series, for periods of 5-30 minutes. The exposure system was: MW generator + adapted load (shortened rectangular waveguide) + Teflon cuvette filled with sample liquid. The effect of MW irradiation is not observable on mulof MW irradiation is not observable on multilamellar vesicles, but only on small unilamellar vesicles. The MW effect is athermal, verified by conventional heating in the same range of temperatures and results in enlarging the size of vesicles. The enlarging effect of MW is opposed to the effect of ultrasounds exposure. It is not clear if effects due to MW are proportional with exposure duration; it seems that this mostly depends on the type of lipid in vesicles. The UV and VIS spectra were recorded to observe the oxidation state of the Chlorophyll and of the lipid. A connection between lipid and Chlorophyll oxidation in irradiated liposomes was observed. The fluorescence and polarization spectra were used in obtaining the transition temperature for different liposome solutions. The temperature of lipid phase transition, as monitored by fluorescence of Chla in liposomes, is not affected by MW exposure. All MW exposure effects observed on liposomes (either observed by monitoring Chla or lipids) seem to be mediated by water. Excitation of water (strong MW absorber) facilitates the hydration of polar head groups of lipids, providing the necessary physical change of lipids and thus explaining the effect of MW on SUV. (authors)

214

Final Report, "Molecular Design of Hydrocarbon Oxidation Catalytic Processes"  

Energy Technology Data Exchange (ETDEWEB)

The main goal of this project had been to use model systems to correlate selectivities in partial oxidation catalysis with the presence of specific sites on the surface of the catalyst. Extensive work was performed this year on characterizing oxygen-treated nickel surfaces by chemical means. Specifically, the surface chemistry of ammonia coadsorbed with atomic oxygen on Ni(110) single-crystal surfaces was studied by temperature-programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS). It was determined that at intermediate oxygen coverages direct ammonia adsorption on nickel sites is suppressed, but a new high-temperature reaction regime is generated at 400 K where NHx surface fragments are rehydrogenated concurrently with the production of water and molecular hydrogen. The extensive isotope scrambling and hydrogen transfer seen from nitrogen- to oxygen-containing surface intermediates, and the optimum yields seen for this 400 K state at intermediate oxygen coverages, strongly suggest the direct interaction of the adsorbed ammonia with oxygen atoms at the end of the –Ni–O- rows that form upon reconstruction of the surface. Hydrogen transfer between ammonia and oxygen appears to take place directly via hydrogen bonding, and to be reversible but biased towards water formation. An equilibrium is reached between the produced water and the reacting surface oxygen and hydrogen. The strong influence of the OH surface groups on the thermal chemistry of the adsorbed ammonia was interpreted in terms of the adsorbing geometry of the OH groups on the surface, and of hydrogen bonding between adsorbed OH and NH3 species. In terms of alcohol reactivity, the adsorption of 2-iodoethanol, a precursor for the preparation of 2-hydroxyethyl and oxametallacycle surface species, was found to lead to two configurations involving either just the iodine atom or both iodine and hydroxyl ends of the molecule. A complex chemical behavior starts around 140 K with the production of small amounts of ethylene and water, most likely via the concerted decomposition or disproportionation of the adsorbed molecular species. The bulk of the 2-iodoethanol decomposes at about 150 K via an initial carbon-iodine scission to form –O(H)CH2CH2– (~80%) and 2-hydroxyethyl (~20%) intermediates. Two competing reactions are involved with the subsequent conversion of the 2-hydroxyethyl species around 160 K, a reductive elimination with surface hydrogen to yield ethanol, and a ?-H elimination to surface vinyl alcohol. The –O(H)CH2CH2–, on the other hand, dehydrogenates to a –OCH2CH2– oxametallacycle species about the same temperature. Both 2-hydroxyethyl and oxametallacycle species tautomerize to acetaldehyde, around 210 K and above 250 K, respectively, and some of that acetaldehyde desorbs while the rest decomposes to hydrogen and carbon monoxide. We contend that a better understanding of the surface chemistry of oxygen-containing surfaces can lead to better selectivities in catalysis. This is arguably the most important issue in the field of catalysis in the near future, and one that impacts several technologies of interest to DOE such as the manufacturing of speciality chemicals and the control and removal of pollutants. Additional work was performed on the characterization of the chemistry of methyl and methylene adsorbed species on oxygen-treated nickel surfaces. Complex chemistry was observed involving not only hydrogenation and dehydrogenation steps, but also C-C couplings and methylene insertions to produce heavier hydrocarbons, and oxygen insertion reactions that yield oxygenates. Finally, a dual titration technique employing xenon and a chemically sensitive probe was developed to identify minority catalytic sites on oxide surfaces. In the case of oxygen-treated Ni(110) single crystals, it was found that both hydrogen transfer with adsorbed water or ammonia and certain hydrocarbon hydrogenation reactions take place at the end of the –Ni–O rows that form in this system. Carbon and nitrogen oxides, on the other hand, display no pre

Professor Francisco Zaera

2007-08-09

215

How Effective Are Simulated Molecular-Level Experiments for Teaching Diffusion and Osmosis?  

Science.gov (United States)

Diffusion and osmosis are central concepts in biology, both at the cellular and organ levels. They are presented several times throughout most introductory biology textbooks (e.g., Freeman, 2002), yet both processes are often difficult for students to understand (Odom, 1995; Zuckerman, 1994; Sanger "et al.", 2001; and results herein). Students…

Meir, Eli; Perry, Judith; Stal, Derek; Maruca, Susan; Klopfer, Eric

2005-01-01

216

Low-level radioactive waste processing at nuclear power plants  

International Nuclear Information System (INIS)

The Solid Radwaste Processing Source Book is presented as a supplement to the Liquid Radwaste Source Book released in 1990 and updated in 1991. The publication is the result of an industry-wide survey, and is intended as a resource for technical and managerial decisions involving of the processing of solid radioactive waste including ''wet'' and ''dry'' active waste as found at both Pressurized and Boiling Water Reactor sites. In addition to information on processes, vendors, volumes, and in-plant management activities, technology under consideration for future use and computer applications are listed. Together with key personnel and contact information contained in the Liquid Source Books, the collected data will be of great use when seeking specific, unbiased experience on which to base decisions related to so processing, disposal policy, or potential economic and regulatory impact

217

Polarization-induced renormalization of molecular levels at metallic and semiconducting surfaces  

DEFF Research Database (Denmark)

On the basis of first-principles G0W0 calculations we systematically study how the electronic levels of a benzene molecule are renormalized by substrate polarization when physisorbed on different metallic and semiconducting surfaces. The polarization-induced reduction in the energy gap between occupied and unoccupied molecular levels is found to scale with the substrate density of states at the Fermi level (for metals) and substrate band gap (for semiconductors). These conclusions are further supported by self-consistent GW calculations on simple lattice models. By expressing the electron self-energy in terms of the substrate’s joint density of states we relate the level shift to the surface electronic structure, thus providing a microscopic explanation of the trends in the GW and G0W0 calculations. While image charge effects are not captured by semilocal and hybrid exchange-correlation functionals, we find that error cancellations lead to remarkably good agreement between the G0W0 and Kohn-Sham energies for the occupied orbitals of the adsorbed molecule.

García Lastra, Juan Maria; Rostgaard, Carsten

2009-01-01

218

Dynamical image-charge effect in molecular tunnel junctions : Beyond energy level alignment  

DEFF Research Database (Denmark)

When an electron tunnels between two metal contacts it temporarily induces an image charge (IC) in the electrodes which acts back on the tunneling electron. It is usually assumed that the IC forms instantaneously such that a static model for the image potential applies. Here we investigate how the finite IC formation time affects charge transport through a molecule suspended between two electrodes. For a single-level model, an analytical treatment shows that the conductance is suppressed by a factor Z(2), where Z is the quasiparticle renormalization factor, compared to the static IC approximation. We show that Z can be expressed either in terms of the plasma frequency of the electrode or as the overlap between electrode wave functions corresponding to an empty and filled level, respectively. First-principles GW calculations for benzene-diamine connected to gold electrodes show that the dynamical corrections can reduce the conductance by more than a factor of two when compared to static GW or density functional theory where the molecular energy levels have been shifted to match the exact quasiparticle levels.

Jin, Chengjun; Thygesen, Kristian Sommer

2014-01-01

219

Treatment of High-Level Waste Arising from Pyrochemical Processes  

International Nuclear Information System (INIS)

JSC “SSC RIAR” has been performing research and development activities in support of closed fuel cycle of fast reactor since the middle of 1960s. Fuel cycle involves fabrication and reprocessing of spent nuclear fuel (SNF) using pyrochemical methods of reprocessing in molten alkali metal chlorides. At present pyrochemical methods of SNF reprocessing in molten chlorides has reached such a level in their development that makes it possible to compare their competitiveness with classic aqueous methods. Their comparative advantage lies in high safety, compactness, high protectability as to nonproliferation of nuclear materials, and reduction of high level waste volume

220

Molecular structure, processing, and tissue distribution of matrilin-4.  

Science.gov (United States)

Matrilin-4 is the most recently identified member of the matrilin family of von Willebrand factor A-like domain containing extracellular matrix adapter proteins. Full-length matrilin-4 was expressed in 293-EBNA cells, purified using affinity tags, and subjected to biochemical characterization. The largest oligomeric form of recombinantly expressed full-length matrilin-4 is a trimer as shown by electron microscopy, SDS-polyacrylamide gel electrophoresis, and mass spectrometry. Proteolytically processed matrilin-4 species were also detected. The cleavage occurs in the short linker region between the second von Willebrand factor A-like domain and the coiled-coil domain leading to the release of large fragments and the formation of dimers and monomers of intact subunits still containing a trimeric coiled-coil. In immunoblots of calvaria extracts similar degradation products could be detected, indicating that a related proteolytic processing occurs in vivo. Matrilin-4 was first observed at day 7.5 post-coitum in mouse embryos. Affinity-purified antibodies detect a broad expression in dense and loose connective tissue, bone, cartilage, central and peripheral nervous systems and in association with basement membranes. In the matrix formed by cultured primary embryonic fibroblasts, matrilin-4 is found in a filamentous network connecting individual cells. PMID:11279097

Klatt, A R; Nitsche, D P; Kobbe, B; Macht, M; Paulsson, M; Wagener, R

2001-05-18

221

Molecular Dynamics Simulations of the Roller Nanoimprint Process: Adhesion and Other Mechanical Characteristics  

OpenAIRE

Abstract Molecular dynamics simulations using tight-binding many body potential are carried out to study the roller imprint process of a gold single crystal. The effect of the roller tooth’s taper angle, imprint depth, imprint temperature, and imprint direction on the imprint force, adhesion, stress distribution, and strain are investigated. A two-stage roller imprint process was obtained from an imprint force curve. The two-stage imprint process included the imprint forming w...

Fang Te-Hua; Wu Cheng-Da; Lin Jen-Fin

2009-01-01

222

Method of processing high-level radioactive wastes  

International Nuclear Information System (INIS)

Purpose: To obtain vitrificated products at relatively low temperatures. Method: High-level radioactive wastes and alkoxides are mixed for reaction and gels thus obtained are heated for vitrification. According to common methods, vitrifications have been produced at temperatures of above 1200 deg C, however, the present method enables the vitrification at temperatures of from 600 deg C to 900 deg C. (Ikeda, J.)

223

Effects of Stimulus Type and Level Repetition on Content-Level Binding in Global/Local Processing  

OpenAIRE

The processing and representation of hierarchical objects not only involves the identification of information at the different levels, but also the binding of the identified content to its respective level. Whereas identification is well understood, little is known about content-level binding. In a recent study, however, it has been shown that attentional priming of certain spatial frequencies is advantageous for this binding. Therefore, the present study investigated effects of related facto...

RonaldHübner

2011-01-01

224

Performance Comparison Of Different Controllers For A Level Process  

Directory of Open Access Journals (Sweden)

Full Text Available The analysis study has been done for a First Order plus Delay Time (FOPDT model controlled by Proportional Integral Derivative (PID, proportional integral (PI and Model Predictive Control (MPC using MATLAB software. The study has been done for both MPC and conventional control methods to design the controller for the level tank system and the results has been compared in terms of rise time,settling time and maximum overshoot. The conventional PID controller gives corrective action only after error has developed but not in advance but MPC provides corrective action in advance. The objective of this study is to investigate the Model predictive control (MPC strategy, analyze and compare the control effects with conventional control strategy in maintaining a water level system. A Comparison between the performance of Conventional controller and MPC Controller has been performed in which MPC Controller gives better system parameter in terms of Rise time (tr, Settling time (ts and maximum overshoot (Mp.

S.Abirami

2014-03-01

225

Performance Comparison Of Different Controllers For A Level Process  

OpenAIRE

The analysis study has been done for a First Order plus Delay Time (FOPDT) model controlled by Proportional Integral Derivative (PID), proportional integral (PI) and Model Predictive Control (MPC) using MATLAB software. The study has been done for both MPC and conventional control methods to design the controller for the level tank system and the results has been compared in terms of rise time,settling time and maximum overshoot. The conventional PID controller gives correctiv...

Abirami, S.; Zahir hussain

2014-01-01

226

Impacts of pr-10a overexpression at the molecular and the phenotypic level.  

Science.gov (United States)

Biotechnological approaches using genetic modifications such as homologous gene overexpression can be used to decode gene functions under well-defined circumstances. However, only the recording of the resulting phenotypes allows inferences about the impact of the modification on the organisms' evolutionary, ecological or economic performance. We here compare a potato wild-type cell line with two genetically engineered cell cultures homologously overexpressing Pathogenesis Related Protein 10a (pr-10a). A detailed analysis of the relative gene-expression patterns of pr-10a and its regulators sebf and pti4 over time provides insights into the molecular response of heterotrophic cells to distinct osmotic and salt-stress conditions. Furthermore, this system serves as an exemplar for the tracing of respiration kinetics as a faster and more sensitive alternative to the laborious and time-consuming recording of growth curves. The utility and characteristics of the resulting data type and the requirements for its appropriate analysis are figured out. It is demonstrated how this novel type of phenotypic information together with the gene-expression-data provides valuable insights into the effect of genetic modifications on the behaviour of cells on both the molecular and the macroscopic level. PMID:23880863

Vaas, Lea A I; Marheine, Maja; Sikorski, Johannes; Göker, Markus; Schumacher, Heinz-Martin

2013-01-01

227

Short-term molecular-level effects of silver nanoparticle exposure on the earthworm, Eisenia fetida  

International Nuclear Information System (INIS)

Short-term changes in levels of expression of nine stress response genes and oxidative damage of proteins were examined in Eisenia fetida exposed to polyvinylpyrrolidone (PVP) coated Ag nanoparticles (Ag-NP) and AgNO3 in natural soils. The responses varied significantly among days with the highest number of significant changes occurring on day three. Similarity in gene expression patterns between Ag-NPs and AgNO3 and significant relationships of expression of CAT and HSP70 with Ag soil concentration suggest similarity in toxicity mechanisms of Ag ions and NPs. Significant increases in the levels of protein carbonyls on day three of the exposure to both ions and Ag-NPs indicate that both treatments induced oxidative stress. Our results suggest that Ag ions drive short term toxicity of Ag-NPs in E. fetida. However, given that 3 and Ag nanoparticles were similar. ? Expression of CAT and HSP70 were correlated with Ag soil concentration. ? Increase in protein carbonyls by ions and nanoparticles on day three. ? The results suggest that short-term toxicity is driven by Ag ions. - Similarity in molecular-level responses between silver nanoparticles (Ag-NPs) and ions suggests that ions Ps) and ions suggests that ions are primarily responsible for short-term toxicity of Ag-NPs to Eisenia fetida.

228

Multi-study Integration of Brain Cancer Transcriptomes Reveals Organ-Level Molecular Signatures  

Science.gov (United States)

We utilized abundant transcriptomic data for the primary classes of brain cancers to study the feasibility of separating all of these diseases simultaneously based on molecular data alone. These signatures were based on a new method reported herein – Identification of Structured Signatures and Classifiers (ISSAC) – that resulted in a brain cancer marker panel of 44 unique genes. Many of these genes have established relevance to the brain cancers examined herein, with others having known roles in cancer biology. Analyses on large-scale data from multiple sources must deal with significant challenges associated with heterogeneity between different published studies, for it was observed that the variation among individual studies often had a larger effect on the transcriptome than did phenotype differences, as is typical. For this reason, we restricted ourselves to studying only cases where we had at least two independent studies performed for each phenotype, and also reprocessed all the raw data from the studies using a unified pre-processing pipeline. We found that learning signatures across multiple datasets greatly enhanced reproducibility and accuracy in predictive performance on truly independent validation sets, even when keeping the size of the training set the same. This was most likely due to the meta-signature encompassing more of the heterogeneity across different sources and conditions, while amplifying signal from the repeated global characteristics of the phenotype. When molecular signatures of brain cancers were constructed from all currently available microarray data, 90% phenotype prediction accuracy, or the accuracy of identifying a particular brain cancer from the background of all phenotypes, was found. Looking forward, we discuss our approach in the context of the eventual development of organ-specific molecular signatures from peripheral fluids such as the blood. PMID:23935471

Sung, Jaeyun; Kim, Pan-Jun; Ma, Shuyi; Funk, Cory C.; Magis, Andrew T.; Wang, Yuliang; Hood, Leroy; Geman, Donald; Price, Nathan D.

2013-01-01

229

Tumor Angiogenic Marker Expression Levels during Tumor Growth: Longitudinal Assessment with Molecularly Targeted Microbubbles and US Imaging  

OpenAIRE

The results of our study suggest that expression levels of different tumor angiogenic markers vary during tumor growth in subcutaneous human breast, ovarian, and pancreatic cancer xenografts in mice and that targeted contrast-enhanced US imaging allows longitudinal noninvasive assessment of the temporal tumor angiogenic molecular marker expression levels in vivo.

Deshpande, Nirupama; Ren, Ying; Foygel, Kira; Rosenberg, Jarrett; Willmann, Ju?rgen K.

2011-01-01

230

Bibliography of atomic and molecular processes. Volume 1, 1978-1981  

International Nuclear Information System (INIS)

This annotated bibliography lists 10,676 works on atomic and molecular processes reported in publications dated 1978-1981. Sources include scientific journals, conference proceedings, and books. Each entry is designated by one or more of the 114 categories of atomic and molecular processes used by the Controlled Fusion Atomic Data Center, Oak Ridge National Laboratory to classify data. Also indicated is whether the work was experimental or theoretical, what energy range was covered, what reactants were investigated, and the county of origin of the first author. Following the bibliographical listing, the entries are indexed according to the categories and according to reactants within each subcategory

231

Observation of Magnetic Level Repulsion in Fe6:Li Molecular Antiferromagnetic Rings  

Science.gov (United States)

Heat capacity (C), magnetic torque, and proton NMR relaxation rate (1/T1) measurements were performed on Fe6:Li single crystals in order to study the crossings between S = 0 and S = 1 and between S = 1 and S = 2 magnetic states of the molecular rings, at magnetic fields Bc1 = 11.7 T and Bc2 = 22.4 T, respectively. C vs B data at 0.78 K show that the energy gap between two states remains finite at Bc's ( ?1/kB = 0.86 K and ?2/kB = 2.36 K) thus proving that levels repel each other. The large ?1 value may also explain the anomalously large width of the peak in 1/T1 vs B, around Bc1. This anticrossing, unexpected in a centrosymmetric system, requires a revision of the Hamiltonian.

Affronte, M.; Cornia, A.; Lascialfari, A.; Borsa, F.; Gatteschi, D.; Hinderer, J.; Horvati?, M.; Jansen, A. G.; Julien, M.-H.

2002-04-01

232

Optimal values of rovibronic energy levels for triplet electronic states of molecular deuterium  

CERN Document Server

Optimal set of 1050 rovibronic energy levels for 35 triplet electronic states of $D_2$ has been obtained by means of a statistical analysis of all available wavenumbers of triplet-triplet rovibronic transitions studied in emission, absorption, laser and anticrossing spectroscopic experiments of various authors. We used a new method of the analysis (Lavrov, Ryazanov, JETP Letters, 2005), which does not need any \\it a priory \\rm assumptions concerning the molecular structure being based on only two fundamental principles: Rydberg-Ritz and maximum likelihood. The method provides the opportunity to obtain the RMS estimates for uncertainties of the experimental wavenumbers independent from those presented in original papers. 234 from 3822 published wavenumber values were found to be spurious, while the remaining set of the data may be divided into 20 subsets (samples) of uniformly precise data having close to normal distributions of random errors within the samples. New experimental wavenumber values of 125 questi...

Lavrov, B P

2008-01-01

233

Molecular Insights into Poly(ADP-ribose Recognition and Processing  

Directory of Open Access Journals (Sweden)

Full Text Available Poly(ADP-ribosylation is a post-translational protein modification involved in the regulation of important cellular functions including DNA repair, transcription, mitosis and apoptosis. The amount of poly(ADP-ribosylation (PAR in cells reflects the balance of synthesis, mediated by the PARP protein family, and degradation, which is catalyzed by a glycohydrolase, PARG. Many of the proteins mediating PAR metabolism possess specialised high affinity PAR-binding modules that allow the efficient sensing or processing of the PAR signal. The identification of four such PAR-binding modules and the characterization of a number of proteins utilising these elements during the last decade has provided important insights into how PAR regulates different cellular activities. The macrodomain represents a unique PAR-binding module which is, in some instances, known to possess enzymatic activity on ADP-ribose derivatives (in addition to PAR-binding. The most recently discovered example for this is the PARG protein, and several available PARG structures have provided an understanding into how the PARG macrodomain evolved into a major enzyme that maintains PAR homeostasis in living cells.

Ivan Ahel

2012-12-01

234

The fabrication of rare earth covalent luminescent hybrid materials with potential molecular bridge by in situ sol-gel process  

International Nuclear Information System (INIS)

1,2,4-Benzenetricar boxylic acid (abbreviated as TMA) was modified to achieve a functional molecular bridge (TMA-APMES) with double reactivity by the reaction with a cross-linking molecule (3-aminopropyl-methyl-diethoxylsiliane, APMES). The modified functional ligand further behaves as a bridge both coordinates to Ln3+ through oxygen atom and occurs in situ sol-gel process with matrix precursor (tetraethoxysilane, TEOS) through co-hydrolysis and co-polycondensation reaction. Then a novel molecular hybrid material (named as hybrid Ln3+) with double chemical bond (Tb-O coordination bond and Si-O covalent bond) resulted. Ultraviolet absorption, phosphorescence, and fluorescence spectra were applied to characterize the photophysical properties of the obtained hybrid material. The strong luminescence of Tb3+ substantiates optimum energy couple and effective intramolecular energy transfer between the triplet state energy of modified ligand bridge and emissive energy level of Tb3+

235

Implications of the admixture process in skin color molecular assessment.  

Science.gov (United States)

The understanding of the complex genotype-phenotype architecture of human pigmentation has clear implications for the evolutionary history of humans, as well as for medical and forensic practices. Although dozens of genes have previously been associated with human skin color, knowledge about this trait remains incomplete. In particular, studies focusing on populations outside the European-North American axis are rare, and, until now, admixed populations have seldom been considered. The present study was designed to help fill this gap. Our objective was to evaluate possible associations of 18 single nucleotide polymorphisms (SNPs), located within nine genes, and one pseudogene with the Melanin Index (MI) in two admixed Brazilian populations (Gaucho, N?=?352; Baiano, N?=?148) with different histories of geographic and ethnic colonization. Of the total sample, four markers were found to be significantly associated with skin color, but only two (SLC24A5 rs1426654, and SLC45A2 rs16891982) were consistently associated with MI in both samples (Gaucho and Baiano). Therefore, only these 2 SNPs should be preliminarily considered to have forensic significance because they consistently showed the association independently of the admixture level of the populations studied. We do not discard that the other two markers (HERC2 rs1129038 and TYR rs1126809) might be also relevant to admixed samples, but additional studies are necessary to confirm the real importance of these markers for skin pigmentation. Finally, our study shows associations of some SNPs with MI in a modern Brazilian admixed sample, with possible applications in forensic genetics. Some classical genetic markers in Euro-North American populations are not associated with MI in our sample. Our results point out the relevance of considering population differences in selecting an appropriate set of SNPs as phenotype predictors in forensic practice. PMID:24809478

Cerqueira, Caio Cesar Silva de; Hünemeier, Tábita; Gomez-Valdés, Jorge; Ramallo, Virgínia; Volasko-Krause, Carla Daiana; Barbosa, Ana Angélica Leal; Vargas-Pinilla, Pedro; Dornelles, Rodrigo Ciconet; Longo, Danaê; Rothhammer, Francisco; Bedoya, Gabriel; Canizales-Quinteros, Samuel; Acuña-Alonzo, Victor; Gallo, Carla; Poletti, Giovanni; González-José, Rolando; Salzano, Francisco Mauro; Callegari-Jacques, Sídia Maria; Schuler-Faccini, Lavínia; Ruiz-Linares, Andrés; Cátira Bortolini, Maria

2014-01-01

236

Low-level radioactive waste processing at nuclear power plants  

International Nuclear Information System (INIS)

The 1991 Liquid Processing Source Book for PWR's provides updated information as a result of an industry-wide survey, and is a revision of the SOURCE BOOK released in February, 1990. The information supplied by radioactive waste managers, operations supervisors, and health physics personnel provides an up-to-date comparison of technical and managerial practices at plants across the United States, and will prove to be a valuable resource when making processing, vendor, and personnel changes or briefing plant managers concerning similar decisions at other utilities. The systems information, description of water management practices, organizational structure, and contact data have been supplied by cognizant plant personnel and are accurate as of the publication date. Volume 2 presents a liquid radwaste sourcebook for pressurized water reactors

237

Slow relaxation process in DNA at different levels of hydration  

OpenAIRE

There are many speculations about the dynamic transition observed in hydrated bio-polymers at temperatures T ? 200 – 230 K being an important factor for enabling of their functions. The transition shows up as a sharp increase of atomic mean-squared displacements above this temperature. The nature of the dynamic transition is not yet clear. Using inelastic neutron scattering we show in this Note that the transition in DNA is related to the appearance of a slow relaxation process. Decrease ...

Sokolov, A. P.; Grimm, H.; Kisliuk, A.; Dianoux, A. J.

2000-01-01

238

Level 1 remedial investigation work plan, 300 Area Process Ponds  

Energy Technology Data Exchange (ETDEWEB)

This report discusses the objectives of the site characterization for the 300 Area Process Ponds which are to identify and quantify contamination at the ponds and to estimate their potential impact on human health and the environment. The results of the site characterization will be used to identify any future actions related to contamination at the site and to identify any additional data requirements needed to support selection of a remedial action. 9 refs., 12 figs., 8 tabs.

1987-06-01

239

University level genetics students’ competencies in selected science process skills  

OpenAIRE

Science process skills are essential for all practicing scientists. These skills include various practices that are needed to glean new knowledge as well as to represent existing knowledge. For example, an ability to use mathematics to represent relationships between variables is important in any scientific discipline. Furthermore, understanding scientific method is imperative in any research field. In addition, being literate with tabulated and graphical data is not only important for the sc...

Aldous, Colleen Michelle

2005-01-01

240

Correlating molecular spectroscopy and molecular chemometrics to explore carbohydrate functional groups and utilization of coproducts from biofuel and biobrewing processing.  

Science.gov (United States)

Dried distillers grains with solubles (DDGS) was coproducts from bioethanol and biobrewing industry. It was an excellent resource of protein and energy feedstuff in China. Conventional studies often focus on traditional nutritional profiles. To data, there is little research on molecular structure-nutrition interaction of carbohydrate in coproducts. In this study, five kinds of corn-grain based DDGS and two kinds of barley-grain based DDGS were collected from different manufactures in the north of China. They were coded as "1, 2, 3, 4, 5, 6, and 7", respectively. The primary purposes of this project were to investigate the molecular structure-nutrition interaction of carbohydrate in coproducts, in terms of (1) carbohydrate-related chemical composition and nutrient profiles, (2) predicted values for energy in coproducts for animal, and (3) in situ digestion of dry matter. The result showed that acid detergent fiber content in corn DDGS and barley DDGS had negative correlation with structural carbohydrate peak area, cellulose compounds, and carbohydrate component peaks (first, second, and total peak area), which were measured with molecular spectroscopy. The correlation between carbohydrate peak area (second and total) and digestible fiber (tdNDF) were negative. There were no correlation between carbohydrate spectral intensities and energy values, carbohydrate subfractions partitioned by CNCPS system, and in situ rumen degradation. The results indicate that carbohydrate spectral profiles (functional groups) are associated with the carbohydrate nutritive values in coproducts from biofuel and biobrewing processing. PMID:24738876

Chen, Limei; Zhang, Xuewei; Yu, Peiqiang

2014-06-01

241

Corrosion and failure processes in high-level waste tanks  

Energy Technology Data Exchange (ETDEWEB)

A large amount of radioactive waste has been stored safely at the Savannah River and Hanford sites over the past 46 years. The aim of this report is to review the experimental corrosion studies at Savannah River and Hanford with the intention of identifying the types and rates of corrosion encountered and indicate how these data contribute to tank failure predictions. The compositions of the High-Level Wastes, mild steels used in the construction of the waste tanks and degradation-modes particularly stress corrosion cracking and pitting are discussed. Current concerns at the Hanford Site are highlighted.

Mahidhara, R.K.; Elleman, T.S.; Murty, K.L. [North Carolina State Univ., Raleigh, NC (United States)

1992-11-01

242

Vitrification processing method and device for high level liquid waste  

International Nuclear Information System (INIS)

A freeze-drying device is assembled to the midway of a line which connects a liquid waste tank and a melter in order to remove water. A freezing facility and a vacuum facility are connected to a drying box. With such a constitution, water is removed before supplying the high level liquid wastes to the melter, and the solid material removed with water is charged into the melter, and a vitrification material is formed. Accordingly, scattering of nuclides generated upon removing water can be reduced, and there is no need to dispose complicated equipments in the melter, thereby simplifying installation. (T.M.)

243

Corrosion and failure processes in high-level waste tanks  

International Nuclear Information System (INIS)

A large amount of radioactive waste has been stored safely at the Savannah River and Hanford sites over the past 46 years. The aim of this report is to review the experimental corrosion studies at Savannah River and Hanford with the intention of identifying the types and rates of corrosion encountered and indicate how these data contribute to tank failure predictions. The compositions of the High-Level Wastes, mild steels used in the construction of the waste tanks and degradation-modes particularly stress corrosion cracking and pitting are discussed. Current concerns at the Hanford Site are highlighted

244

RNA-Seq and molecular docking reveal multi-level pesticide resistance in the bed bug  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Bed bugs (Cimex lectularius are hematophagous nocturnal parasites of humans that have attained high impact status due to their worldwide resurgence. The sudden and rampant resurgence of C. lectularius has been attributed to numerous factors including frequent international travel, narrower pest management practices, and insecticide resistance. Results We performed a next-generation RNA sequencing (RNA-Seq experiment to find differentially expressed genes between pesticide-resistant (PR and pesticide-susceptible (PS strains of C. lectularius. A reference transcriptome database of 51,492 expressed sequence tags (ESTs was created by combining the databases derived from de novo assembled mRNA-Seq tags (30,404 ESTs and our previous 454 pyrosequenced database (21,088 ESTs. The two-way GLMseq analysis revealed ~15,000 highly significant differentially expressed ESTs between the PR and PS strains. Among the top 5,000 differentially expressed ESTs, 109 putative defense genes (cuticular proteins, cytochrome P450s, antioxidant genes, ABC transporters, glutathione S-transferases, carboxylesterases and acetyl cholinesterase involved in penetration resistance and metabolic resistance were identified. Tissue and development-specific expression of P450 CYP3 clan members showed high mRNA levels in the cuticle, Malpighian tubules, and midgut; and in early instar nymphs, respectively. Lastly, molecular modeling and docking of a candidate cytochrome P450 (CYP397A1V2 revealed the flexibility of the deduced protein to metabolize a broad range of insecticide substrates including DDT, deltamethrin, permethrin, and imidacloprid. Conclusions We developed significant molecular resources for C. lectularius putatively involved in metabolic resistance as well as those participating in other modes of insecticide resistance. RNA-Seq profiles of PR strains combined with tissue-specific profiles and molecular docking revealed multi-level insecticide resistance in C. lectularius. Future research that is targeted towards RNA interference (RNAi on the identified metabolic targets such as cytochrome P450s and cuticular proteins could lay the foundation for a better understanding of the genetic basis of insecticide resistance in C. lectularius.

Mamidala Praveen

2012-01-01

245

Molecular-Level Understanding of the Photocatalytic Activity Difference between Anatase and Rutile Nanoparticles.  

Science.gov (United States)

The generation of oxidants on illuminated photocatalysts and their participation in subsequent reactions are the main basis of the widely investigated photocatalytic processes for environmental remediation and selective oxidation. Here, the generation and the subsequent diffusion of (.) OH from the illuminated TiO2 surface to the solution bulk were directly observed using a single-molecule detection method and this molecular phenomenon could explain the different macroscopic behavior of anatase and rutile in photocatalysis. The mobile (.) OH is generated on anatase but not on rutile. Therefore, the photocatalytic oxidation on rutile is limited to adsorbed substrates whereas that on anatase is more facile and versatile owing to the presence of mobile (.) OH. The ability of anatase to generate mobile (.) OH is proposed as a previously unrecognized key factor that explains the common observations that anatase has higher activity than rutile for many photooxidative reactions. PMID:25314627

Kim, Wooyul; Tachikawa, Takashi; Moon, Gun-Hee; Majima, Tetsuro; Choi, Wonyong

2014-12-15

246

High level radioactive waste vitrification process equipment component testing  

International Nuclear Information System (INIS)

Remote operability and maintainability of vitrification equipment were assessed under shielded-cell conditions. The equipment tested will be applied to immobilize high-level and transuranic liquid waste slurries that resulted from plutonium production for defense weapons. Equipment tested included: a turntable for handling waste canisters under the melter; a removable discharge cone in the melter overflow section; a thermocouple jumper that extends into a shielded cell; remote instrument and electrical connectors; remote, mechanical, and heat transfer aspects of the melter glass overflow section; a reamer to clean out plugged nozzles in the melter top; a closed circuit camera to view the melter interior; and a device to retrieve samples of the glass product. A test was also conducted to evaluate liquid metals for use in a liquid metal sealing system

247

Network-level molecular evolutionary analysis of the insulin/TOR signal transduction pathway across 12 Drosophila genomes  

OpenAIRE

Biological function is based on complex networks consisting of large numbers of interacting molecules. The evolutionary properties of molecular networks and, in particular, the impact of network architecture on the sequence evolution of its individual components are, nonetheless, still poorly understood. Here, we conducted a fine-scale network-level molecular evolutionary analysis of the insulin/TOR pathway across 12 species of Drosophila. We found that the insulin/TOR pathway components are ...

Alvarez-ponce, David; Aguade?, Montserrat; Rozas, Julio

2009-01-01

248

High levels of melatonin generated during the brewing process.  

Science.gov (United States)

Beer is a beverage consumed worldwide. It is produced from cereals (barley or wheat) and contains a wide array of bioactive phytochemicals and nutraceutical compounds. Specifically, high melatonin concentrations have been found in beer. Beers with high alcohol content are those that present the greatest concentrations of melatonin and vice versa. In this study, gel filtration chromatography and ELISA were combined for melatonin determination. We brewed beer to determine, for the first time, the beer production steps in which melatonin appears. We conclude that the barley, which is malted and ground in the early process, and the yeast, during the second fermentation, are the largest contributors to the enrichment of the beer with melatonin. PMID:23607887

Garcia-Moreno, H; Calvo, J R; Maldonado, M D

2013-08-01

249

Constant current charging process of MV-level Marx generator  

International Nuclear Information System (INIS)

A 4 MV pre-triggered Marx generator charged with series resistor has been designed. For better output property, higher charging efficiency and lower voltage difference between stages, the study conducted the analytic solution of its constant current charging (CCC) process. The results show that the voltage differences between different stages of capacitors are in direct proportion to charging resistance, capacitance and charging speed, but are independent of time; the charging efficiency improves with time, but is independent of charging speed. This solution is universally applicable. The simulation of CCC for the Marx generator was done with PSpice, and the results agree with the analytic solution. Compared to constant voltage charging (CVC) with 10 k? charging resistors, 400 nF capacitors and 10 kV/s charging speed, the charging efficiency of CCC is 90%, double that of CVC and the charging time is only one third. (authors)

250

Real Time Implementation of Wiener Model PI (WMPI) Controller in a Conical Tank Liquid Level Process  

OpenAIRE

Level control is very important for the successful operation of most chemical and biochemical industries since it is through the proper control of flows and levels that the desired production rates and inventories can be achieved. The aim of this study was the development and real time implementation of a Wiener Model based PI Controller (WMPIC) for a conical tank level process. The conical tank level process exhibits severe static non-linear behavior and dynamic characteristics. Here, a WMPI...

Bhaba, P. K.; Sathishbabu, S.; Asokan, A.; Karunanithi, T.

2007-01-01

251

Belowground Carbon Cycling Processes at the Molecular Scale: An EMSL Science Theme Advisory Panel Workshop  

Energy Technology Data Exchange (ETDEWEB)

As part of the Belowground Carbon Cycling Processes at the Molecular Scale workshop, an EMSL Science Theme Advisory Panel meeting held in February 2013, attendees discussed critical biogeochemical processes that regulate carbon cycling in soil. The meeting attendees determined that as a national scientific user facility, EMSL can provide the tools and expertise needed to elucidate the molecular foundation that underlies mechanistic descriptions of biogeochemical processes that control carbon allocation and fluxes at the terrestrial/atmospheric interface in landscape and regional climate models. Consequently, the workshop's goal was to identify the science gaps that hinder either development of mechanistic description of critical processes or their accurate representation in climate models. In part, this report offers recommendations for future EMSL activities in this research area. The workshop was co-chaired by Dr. Nancy Hess (EMSL) and Dr. Gordon Brown (Stanford University).

Hess, Nancy J.; Brown, Gordon E.; Plata, Charity

2014-02-21

252

Determination of cadmium at ultra-trace levels by CPE-molecular fluorescence combined methodology  

Energy Technology Data Exchange (ETDEWEB)

A highly sensitive micelle-mediated extraction methodology for the preconcentration and determination of trace levels of cadmium by molecular fluorescence has been developed. Metal was complexed with o-phenanthroline (o-phen) and eosin (eo) at pH 7.6 in buffer Tris medium and quantitatively extracted into a small volume of surfactant-rich phase of PONPE 7.5 after centrifugating. The chemical variables affecting cloud point extraction (CPE) were evaluated and optimized. The RSD for six replicates of cadmium determinations at 0.84 {mu}g L{sup -1} level was 1.17%. The linearity range using the preconcentration system was between 2.79 x 10{sup -3} {mu}g L{sup -1} and 2.81 {mu}g L{sup -1} with a correlation coefficient of 0.99. Under the optimal conditions, it obtained a LOD of 8.38 x 10{sup -4} {mu}g L{sup -1} and LOQ of 2.79 x 10{sup -3} {mu}g L{sup -1}. The method presented good sensitivity and selectivity and was applied to the determination of trace amounts of cadmium in commercially bottled mineral water, tap water and water well samples with satisfactory results. The proposed method is an innovative application of CPE-luminescence to metal analysis comparable in sensitivity and accuracy with atomic spectroscopies.

Talio, Maria Carolina [Instituto de Quimica de San Luis (INQUISAL-CONICET), Chacabuco y Pedernera, 5700 San Luis (Argentina); Luconi, Marta O. [Area de Quimica Analitica, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, San Luis (Argentina); Masi, Adriana N. [Area de Bromatologia- Ensayo y Valoracion de Medicamentos, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, San Luis (Argentina); Instituto de Quimica de San Luis (INQUISAL-CONICET), Chacabuco y Pedernera, 5700 San Luis (Argentina); Fernandez, Liliana P., E-mail: lfernand@unsl.edu.ar [Area de Quimica Analitica, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, San Luis (Argentina); Instituto de Quimica de San Luis (INQUISAL-CONICET), Chacabuco y Pedernera, 5700 San Luis (Argentina)

2009-10-15

253

Determination of cadmium at ultra-trace levels by CPE-molecular fluorescence combined methodology  

International Nuclear Information System (INIS)

A highly sensitive micelle-mediated extraction methodology for the preconcentration and determination of trace levels of cadmium by molecular fluorescence has been developed. Metal was complexed with o-phenanthroline (o-phen) and eosin (eo) at pH 7.6 in buffer Tris medium and quantitatively extracted into a small volume of surfactant-rich phase of PONPE 7.5 after centrifugating. The chemical variables affecting cloud point extraction (CPE) were evaluated and optimized. The RSD for six replicates of cadmium determinations at 0.84 ?g L-1 level was 1.17%. The linearity range using the preconcentration system was between 2.79 x 10-3 ?g L-1 and 2.81 ?g L-1 with a correlation coefficient of 0.99. Under the optimal conditions, it obtained a LOD of 8.38 x 10-4 ?g L-1 and LOQ of 2.79 x 10-3 ?g L-1. The method presented good sensitivity and selectivity and was applied to the determination of trace amounts of cadmium in commercially bottled mineral water, tap water and water well samples with satisfactory results. The proposed method is an innovative application of CPE-luminescence to metal analysis comparable in sensitivity and accuracy with atomic spectroscopies.

254

Incisive probing of intermolecular interactions in molecular crystals: core level spectroscopy combined with density functional theory.  

Science.gov (United States)

The ?-form of crystalline para-aminobenzoic acid (PABA) has been examined as a model system for demonstrating how the core level spectroscopies X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine-structure (NEXAFS) can be combined with CASTEP density functional theory (DFT) to provide reliable modeling of intermolecular bonding in organic molecular crystals. Through its dependence on unoccupied valence states NEXAFS is an extremely sensitive probe of variations in intermolecular bonding. Prediction of NEXAFS spectra by CASTEP, in combination with core level shifts predicted by WIEN2K, reproduced experimentally observed data very well when all significant intermolecular interactions were correctly taken into account. CASTEP-predicted NEXAFS spectra for the crystalline state were compared with those for an isolated PABA monomer to examine the impact of intermolecular interactions and local environment in the solid state. The effects of the loss of hydrogen-bonding in carboxylic acid dimers and intermolecular hydrogen bonding between amino and carboxylic acid moieties are evident, with energy shifts and intensity variations of NEXAFS features arising from the associated differences in electronic structure and bonding. PMID:25248405

Stevens, Joanna S; Seabourne, Che R; Jaye, Cherno; Fischer, Daniel A; Scott, Andrew J; Schroeder, Sven L M

2014-10-23

255

Theory of molecular rate processes in the presence of intense laser radiation  

Science.gov (United States)

The present paper deals with the influence of intense laser radiation on gas-phase molecular rate processes. Representations of the radiation field, the particle system, and the interaction involving these two entities are discussed from a general rather than abstract point of view. The theoretical methods applied are outlined, and the formalism employed is illustrated by application to a variety of specific processes. Quantum mechanical and semiclassical treatments of representative atom-atom and atom-diatom collision processes in the presence of a field are examined, and examples of bound-continuum processes and heterogeneous catalysis are discussed within the framework of both quantum-mechanical and semiclassical theories.

George, T. F.; Zimmerman, I. H.; Devries, P. L.; Yuan, J.-M.; Lam, K.-S.; Bellum, J. C.; Lee, H.-W.; Slutsky, M. S.; Lin, J.-T.

1979-01-01

256

IAEA technical meeting on 'Technical aspects of atomic and molecular data processing and exchange'. Summary report  

International Nuclear Information System (INIS)

The proceedings of the IAEA Advisory Group Meeting on 'Technical Aspects of Atomic and Molecular Data Processing and Exchange' (17th Meeting of A+M Data Centres and ALADDIN Network), held on 6-7 October, 2003 in Vienna, Austria are briefly described. The meeting conclusions and recommendations on the priorities in A+M data compilation and evaluation, and on the technical aspects of data processing, exchange, and distribution are also presented. (author)

257

Molecular and kinetic modeling of peroxidation process of organic compounds: the case of aliphatic ethers  

OpenAIRE

A great number of organic compounds, commonly used, could become instable if stored under poor conditions or for over-long periods in contact with air. Indeed, they can react with molecular oxygen, also at room temperature, in a process of autoxidation (peroxidation), which is self-propagating and based on free radical reactions. The products of this process are peroxidized compounds (hydroperoxide or alkyl peroxides), thermodynamically instable and well-known to be the cause of many laborato...

Di Tommaso, Stefania

2011-01-01

258

Chronic alcohol exposure negatively impacts the physiological and molecular parameters of the renal biotin reabsorption process  

OpenAIRE

Normal body homeostasis of biotin is critically dependent on its renal recovery by kidney proximal tubular epithelial cells, a process that is mediated by the sodium-dependent multivitamin transporter (SMVT; a product of the SLC5A6 gene). Chronic ethanol consumption interferes with the renal reabsorption process of a variety of nutrients, including water-soluble vitamins. To date, however, there is nothing known about the effect of chronic alcohol feeding on physiological and molecular parame...

Subramanian, Veedamali S.; Subramanya, Sandeep B.; Said, Hamid M.

2011-01-01

259

Stochastic dynamics of small ensembles of non-processive molecular motors: The parallel cluster model  

Energy Technology Data Exchange (ETDEWEB)

Non-processive molecular motors have to work together in ensembles in order to generate appreciable levels of force or movement. In skeletal muscle, for example, hundreds of myosin II molecules cooperate in thick filaments. In non-muscle cells, by contrast, small groups with few tens of non-muscle myosin II motors contribute to essential cellular processes such as transport, shape changes, or mechanosensing. Here we introduce a detailed and analytically tractable model for this important situation. Using a three-state crossbridge model for the myosin II motor cycle and exploiting the assumptions of fast power stroke kinetics and equal load sharing between motors in equivalent states, we reduce the stochastic reaction network to a one-step master equation for the binding and unbinding dynamics (parallel cluster model) and derive the rules for ensemble movement. We find that for constant external load, ensemble dynamics is strongly shaped by the catch bond character of myosin II, which leads to an increase of the fraction of bound motors under load and thus to firm attachment even for small ensembles. This adaptation to load results in a concave force-velocity relation described by a Hill relation. For external load provided by a linear spring, myosin II ensembles dynamically adjust themselves towards an isometric state with constant average position and load. The dynamics of the ensembles is now determined mainly by the distribution of motors over the different kinds of bound states. For increasing stiffness of the external spring, there is a sharp transition beyond which myosin II can no longer perform the power stroke. Slow unbinding from the pre-power-stroke state protects the ensembles against detachment.

Erdmann, Thorsten; Albert, Philipp J.; Schwarz, Ulrich S. [BioQuant, Heidelberg University, Im Neuenheimer Feld 267, 69120 Heidelberg, Germany and Institute for Theoretical Physics, Heidelberg University, Philosophenweg 19, 69120 Heidelberg (Germany)

2013-11-07

260

MULTI LEVEL SEMANTIC EXTRACTION FOR CRICKET VIDEO BY TEXT PROCESSING  

Directory of Open Access Journals (Sweden)

Full Text Available Semantic video analysis, indexing and retrieval are necessary for effective utilization of video repositories. The semantics can be extracted from the semantic carriers such as voice and video text. Super imposed text is the proper source to extract semantics of the video which will increase the efficiency of retrieval system. This paper proposes a semiautomatic method to generate annotation for cricket videos and an automated tool- DLER, to extract the semantics of cricket video. The DLER tool provides a fast and robust approach for text Detection, Localization, Extraction, and Reorganization in video frames, which is flexible and customer friendly. The DLER integrates all the pre-processing steps and the OCR steps in to a single unit. The annotator can pick the ROI, increase or decrease the threshold, contrast, brightness or inverse the image based on the typeof the broadcasted video. The tool has been implemented and tested with cricket video and the results of the experiments are promising. Finally conclusion and future work has been discussed.

Dr. SUNITHA ABBURU

2010-10-01

261

Model Based Control For Interacting And Non-Interacting Level Process Using Labview  

Directory of Open Access Journals (Sweden)

Full Text Available Recent advancements in process industries have enabled the development of combination of interacting and non-interacting of process tank level control system. An experimental setup of three tank level process in interacting and non- interacting mode was studied, to obtain the process models. Different control schemes such as Internal model controller (IMC, IMC-PID and Proportional –Integral and Derivative (PID were implemented. The goal of the model-based controller is to compensate for shifts in the process and maintain the liquid level on target. The performance of different control schemes were investigated through computer simulation.

M.LAVANYA, P.ARAVIND, M.VALLUVAN, DR.B.ELIZABETH CAROLINE

2013-07-01

262

Molden: a pre- and post-processing program for molecular and electronic structures.  

Science.gov (United States)

Molden is a software package for pre- and postprocessing of computational chemistry program data. Interfacing to the ab initio programs Games-US/UK and Gaussian and to the semi-empirical package MOPAC is provided. The emphasis is on computation and visualization of electronic and molecular properties but, e.g., reaction pathways can be simulated as well. Some molecular properties of interest are processed directly from the output of the computational chemistry programs, others are calculated in MOLDEN before display. The package features different options to display MOLecular electronic DENsity, each focusing on a different structural aspect: molecular orbitals, electron density, molecular minus atomic density and the Laplacian of the electron density. To display difference density, either the spherically averaged atomic density or the oriented ground state atomic density can be used for a number of standard basis sets. The quantum mechanical electrostatic potential or a distributed multiple expansion derived electrostatic potential can be calculated and atomic charges can be fitted to these potentials calculated on Connolly surface(s). Reaction pathways and molecular vibrations can be visualized. Input structures can be generated with a Z-matrix editor. A variety of graphics languages is supported: XWindows, postscript, VRML and Povray format. PMID:10721501

Schaftenaar, G; Noordik, J H

2000-02-01

263

Application of nonlinear optical techniques for the investigation of molecular properties and collisional processes  

International Nuclear Information System (INIS)

Molecular collisional processes were studied by using two different nonlinear optical techniques utilizing CO2 lasers. The first study used the techniques of saturation spectroscopy to study the momentum transfer in one direction which occurs when CO2 collides with itself, H2, Ne, NH3, and CH3F. Average CO2 velocity changes determined from these experiments were typically 1/10 the thermal velocity or less. A theoretical model was also developed to explain the experimental observations of CO2 with foreign gas perturbers. Generally good agreement between this model and the data was obtained. The second technique utilized the high-resolution capabilities of Doppler-free two-photon absorption (DFTPA) for the study of molecular properties and collisional processes in the two molecules CH3F and NH3. The first observation of DFTPA in molecular systems using two fixed-frequency CO2 optical fields in combination with molecular Stark tuning is reported. The pressure broadening coefficient and the pressure shift of the O ? ?3 transition were measured; broadening coefficients for the foreign gas perturbers of He and CF3I were determined. A self-broadening coefficient of the O ? 2?2 transition was also measured; foreign gas broadening coefficients for the collision partners H2, D2, He, Ne, and Xe were determined. Spectroscopic information was also obtained about these two molecular systems. (62 figures, 33 tables, 182 references) (U.S.)

264

An investigation of substituted aromatic isocyanide based molecular-level wires on metal surfaces  

Science.gov (United States)

Ever since hemiquinone was presented as the first potential conductor having an electron donor catechol moiety and an electron acceptor quinone component separated by an aliphatic insulator, thus behaving as a rectifier. However, due to experimental limitations, it was not until 1988 that this rectifying behavior could be confirmed by scanning tunneling microscopic measurements, but even then these early experiments were marred by irreproducibility. Since then, with rapidly improving technology, different strategies were developed to probe the conducting properties of different kinds of molecules with much improved reducibility. With these experimental probes the design of a molecular-level conductor essentially consists of selecting a combination of the backbone of the molecule, its functional anchoring groups and the choice of the metal electrode that all complement each other. In this study, the conduction properties of aromatic isocyanide-based molecules were studied on different metal surfaces. 1,4 phenyldiisocyanide (PDI), 2,3,5,6-Tetrachloro 1,4-phenyldiisocyanide (TMPDI) and 2,3,5,6-Tetramethyl 1,4-phenyldiisocyanide (TMPDI) are the simplest molecular-level linker conductors used in this study. Organometallic polymers of varying lengths were also studied; (CNC6H4NC)2W(DPPE) 2 (1W), (CNC6H4NC)3(W(DPPE)2) 2 (2W) and (CNC6H4NC)4(W(DPPE) 2)3 (3W) were probed for their conduction properties. Before the conduction properties can be investigated, the surface manner in which the linker molecules bond to the surface of a metal electrode is investigated. Such a study has been performed on solution self-assembled monolayers (SAMs) of the linker and organometallic polymer molecules on evaporated meal films. In order to perform a more systematic study, the linker molecules were adsorbed onto single crystal Pd(111) surfaces and ultra high vacuum surface science techniques were used to investigate the surface chemistry. Reflection-Absorption Infrared Spectroscopy, (RAIRS), X-ray photoelectron spectroscopy (XPS) and temperature programmed desorption spectroscopy (TPD) were the surface science techniques used in this study.

Habeeb, Zeeshan

265

Molecular Characterization of Soybean Mosaic Virus NIa Protein and its Processing Event in Bacterial Expression  

Directory of Open Access Journals (Sweden)

Full Text Available Soybean mosaic virus (SMV-CN18 is an Rsv resistance-breaking (RB isolate to overcome soybean resistance genes Rsv1, Rsv3 and Rsv4. The aim of this study was to characterize nuclear inclusion protein a (NIa protein of RB isolate at the molecular level and demonstrate its processing into genome-linked protein (VPg and NIa-Pro domains in Esherichia coli containing a bacterial expression pET vector inserted with NIa gene. The full-length of NIa gene was synthesized by reverse transcription-polymerase chain reaction (RT-PCR and its 1298 nucleotides (nt and 432 amino acids (aa were deduced. The nt and aa sequences of NIa gene of SMV-CN18 shared high identities with the corresponding sequences of the NIa gene of the known SMV isolates, suggesting that the NIa is a highly conserved protein. The NIa-Pro domain contains a highly conserved structural motif for proteolysis, while the VPg domain contains a nuclear localization signal (NLS, a putative NTP-binding site and cellular factor-binding sites. The phylogenetic tree revealed that less divergence of NIa protein exists among twelve SMV isolates, which can be supported by a low bootstrap value between clades. In addition, the full-length of NIa gene, amplified by RT-PCR, was ligated into pET-28b E. coli expression vector with an N-terminal His6-tag. Optimal conditions for expression were at 1mM treatment of IPTG at 25°C for 5 hr. The released protein from bacterial lysates remained soluble and proved the processing form of the NIa polyprotein. E. coli expression system shows the processed product of 29 kDa VPg in SDS-PAGE confirmed by western blot analysis in both crude extracts and purified elution products, using Ni2+-NTA resin. The present study indicates that the N-terminal region of NIa which is processed and expressed in bacteria.

Bong K. Choi

2006-01-01

266

Vibrational origin of the fast relaxation processes in molecular glass-formers  

CERN Document Server

We study the interaction of the relaxation processes with the density fluctuations by molecular dynamics simulation of a flexible molecule model for o-terphenyl (oTP) in the liquid and supercooled phases. We find evidence, besides the structural relaxation, of a secondary vibrational relaxation whose characteristic time, few ps, is slightly temperature dependent. This i) confirms the result by Monaco et al. [Phys. Rev, E 62, 7595 (2000)] of the vibrational nature of the fast relaxation observed in Brillouin Light Scattering (BLS) experiments in oTP; and ii) poses a caveat on the interpretation of the BLS spectra of molecular systems in terms of a purely center of mass dynamics.

Mossa, S; Ruocco, G

2002-01-01

267

La modificación covalente de proteínas. Un nivel cualitativamente superior de la información molecular / Covalent Modifications of Proteins. A qualitative higher level of molecular information  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Introducción: La información molecular es una propiedad principal de las biomacromoléculas, especialmente proteínas y ácidos nucleicos, que permite la realización de funciones con un alto grado de especificidad. Ella deriva de la variedad en los componentes de las macromoléculas. Objetivo: Demostrar [...] que la modificación covalente de proteínas constituye un nivel nuevo y superior de información molecular. Método: Se analizaron artículos de los últimos 5 años, publicados en revistas nacionales y de circulación internacional, disponibles en las bases de datos HINARI, PubMed y Perii y localizados mediante el sitio www.infomed.sld.cu. Desarrollo: Se exponen los mecanismos y características principales del proceso y posteriormente algunos de los efectos principales de la modificación covalente sobre las funciones y propiedades de las proteínas. Conclusiones: La modificación covalente es un mecanismo que amplía el campo de acción de las proteínas permitiendo un rápido cambio en sus propiedades funcionales y, por lo tanto, constituye un nivel nuevo y cualitativamente superior de información molecular. Abstract in english Introduction: Molecular information is an essential property of biomacromolecules, especially proteins and nucleic acids. This property allows carrying out specific functions. It derives from variability of macromolecules components. Objetive: To prove that covalent modification of proteins represen [...] ts a new and higher level of molecular information. Method: Papers published during the last five years in national and international journals were analyzed. These articles are available in HINARI, PubMed, and Perii databases and were localized through www.infomed.sld.cu. Main text: First, the mechanism and features of covalent modifications of protein are presented. Next, the principal effects on protein functions and properties are analyzed. Conclusions: We conclude that covalent modification of proteins represents a new and higher level of molecular information.

Rolando A, Hernández Fernández.

2014-02-01

268

Ecotoxicity of triphenyltin on the marine copepod Tigriopus japonicus at various biological organisations: from molecular to population-level effects.  

Science.gov (United States)

Triphenyltin compounds (TPTs), as effective biocides for different industrial and agricultural purposes, have been detected in coastal marine environments worldwide, in particular in Asian countries. However, little is known about their toxicity to marine organisms. This study comprehensively investigated the molecular, individual and population responses of the marine copepod, Tigriopus japonicus upon waterborne exposure to TPT chloride (TPTCl). Our results indicated that TPTCl was highly toxic to adult T. japonicus, with a 96-h LC50 concentration at 6.3 ?g/L. As shown in a chronic full life-cycle test, T. japonicus exposed to 1.0 ?g/L TPTCl exhibited a delay in development and a significant reduction of population growth, in terms of the intrinsic rate of increase (r m ). Based on the negative relationship between the r m and exposure concentration, a critical effect concentration was estimated at 1.6 ?g/L TPTCl; at or above which population extinction could occur. At 0.1 ?g/L TPTCl or above, the sex ratio of the second generation of the copepod was significantly altered and changed to a male-biased population. At molecular level, the inhibition of the transcriptional expression of glutathione S-transferase related genes might lead to dysfunction of detoxification, and the inhibition of retinoid X receptor mRNA expression implied an interruption of the growth and moulting process in T. japonicus. As the only gene that observed up-regulated in this study, the expression of heat shock protein 70 (hsp70) increased in a concentration-dependent manner, indicating its function in protecting the copepod from TPT-mediated oxidative stress. The study advances our understanding on the ecotoxicity of TPT, and provides some initial data on its toxic mechanisms in small crustaceans like copepods. PMID:24981692

Yi, Andy Xianliang; Han, Jeonghoon; Lee, Jae-Seong; Leung, Kenneth M Y

2014-09-01

269

Comparison of algorithms for the calculation of molecular vibrational level densities.  

Science.gov (United States)

Level densities of vibrational degrees of freedom are calculated numerically with formulas based on the inversion of the canonical vibrational partition function. The calculated level densities are compared with other approximate equations from literature and with the exact Beyer-Swinehart values, for which a simplified but equivalent version is given. All approximate equations agree at high excitation energies, but our results are vastly superior at low energies for large molecules. The results presented here are therefore of particular relevance for thermal processes of very large molecules, e.g., of biological nature, for which the exact state counting can be prohibitively slow. Furthermore, it is valid for situations where anharmonic motion significantly influences the thermal properties. PMID:18500852

Hansen, K

2008-05-21

270

PIM 2005: The Fourth Conference on Isotopic and Molecular Processes. Abstracts  

International Nuclear Information System (INIS)

The proceedings of the Fourth Conference on Isotopic and Molecular Processes held on September 25 - 27, 2003 in Cluj-Napoca, Romania, contains contributions presented as plenary lectures, oral presentations and posters in four sections, namely: 1. Isotopic separation, labelled compounds and applications; 2. Advanced molecular systems; 3. Mass spectrometry, chromatography, atomic and molecular spectroscopy; 4. Biophysics and environmental physics. The main topics treated in this conference were isotope production, separation and enrichment as well as stable isotope applications. Also, studies on isotope effects in different fields are reported. Besides reports on isotope effects, exchange and separation, new methods of preparation and labelling the compounds used particularly in nuclear medicine are presented. Environmental studies by means of stable isotope and radon monitoring are described, as well as applications of radiation effects and various nuclear methods in medicine

271

Effect of low molecular fraction of thymus humoral factor on blood formation processes of irradiated mice  

International Nuclear Information System (INIS)

The effect of low-molecular fraction of thymus humoral factor on blood formation in mice irradiated at 4 Gy was studied. It is shown that injection of low-molecular fraction of thymus hymoral factor to irradiated animals affects proliferative processes in spleen and bone marrow, however the degree of the effect depends on the injection scheme of the preparation. Application of mathematical planning methods of the experiment enables to analyze various injection schemes of low-molecular fraction of thymus humoral factor on the investigated indices. The optimal scheme of preparation injection is determined: 1st injection with the dose of 10 mkg/kg following 4 hour after irradiation, 2d injection - with the same dose in 7-21 days

272

Molecular-level modeling of the viscoelasticity of crosslinked polymers: Effect of time and temperature  

Energy Technology Data Exchange (ETDEWEB)

We present a new molecular-level picture of chain dynamics for describing the viscoelasticity of crosslinked polymers. The associated mathematical model consists of a time-dependent momentum balance on a representative polymer segment in the crosslinked network, plus phenomenological expressions for forces acting on the segments. These include a cohesive force that accounts for intermolecular attraction, an entropic force describing the thermodynamics governing chain conformations, and a frictional force that captures the temperature dependence of relative chain motion. We treat the case of oscillatory uniaxial deformation. Solution of the model equations in the frequency domain yields the dynamic moduli as functions of temperature and frequency. The model reproduces all of the qualitative features of experimental dynamic modulus data across the complete spectrum of time and temperature, spanning the glassy zone, the {beta} transition, the dynamic glass transition, and the rubbery zone. All of the model parameters can be evaluated through the use of independent experimental data. Comparison of model predictions with experimental data yields good quantitative agreement outside of the glass transition region. {copyright} {ital 1997 Society of Rheology.}

Simon, P.P.; Ploehn, H.J. [Department of Chemical Engineering, University of South Carolina, Swearingen Engineering Center, Columbia, South Carolina 29208 (United States)

1997-05-01

273

In-situ molecular-level elucidation of organofluorine binding sites in a whole peat soil.  

Science.gov (United States)

The chemical nature of xenobiotic binding sites in soils is of vital importance to environmental biogeochemistry. Interactions between xenobiotics and the naturally occurring organic constituents of soils are strongly correlated to environmental persistence, bioaccessibility, and ecotoxicity. Nevertheless, because of the complex structural and chemical heterogeneity of soils, studies of these interactions are most commonly performed indirectly, using correlative methods, fractionation, or chemical modification. Here we identify the organic components of an unmodified peat soil where some organofluorine xenobiotic compounds interact using direct molecular-level methods. Using (19)F?(1)H cross-polarization magic angle spinning (CP-MAS) nuclear magnetic resonance (NMR) spectroscopy, the (19)F nuclei of organofluorine compounds are used to induce observable transverse magnetization in the (1)H nuclei of organic components of the soil with which they interact after sorption. The observed (19)F?(1)H CP-MAS spectra and dynamics are compared to those produced using model soil organic compounds, lignin and albumin. It is found that lignin-like components can account for the interactions observed in this soil for heptafluoronaphthol (HFNap) while protein structures can account for the interactions observed for perfluorooctanoic acid (PFOA). This study employs novel comprehensive multi-phase (CMP) NMR technology that permits the application of solution-, gel-, and solid-state NMR experiments on intact soil samples in their swollen state. PMID:22946434

Longstaffe, James G; Courtier-Murias, Denis; Soong, Ronald; Simpson, Myrna J; Maas, Werner E; Fey, Michael; Hutchins, Howard; Krishnamurthy, Sridevi; Struppe, Jochem; Alaee, Mehran; Kumar, Rajeev; Monette, Martine; Stronks, Henry J; Simpson, André J

2012-10-01

274

Molecular analyses reveal high levels of eukaryotic richness associated with enigmatic deep-sea protists (Komokiacea)  

DEFF Research Database (Denmark)

Komokiaceans are testate agglutinated protists, extremely diverse and abundant in the deep sea. About 40 species are described and share the same main morpholog- ical feature: a test consisting of narrow branching tubules forming a complex system. In some species, the interstices between the tubules are filled by sediment, creating a mudball structure. Because of their unusual and sometimes featureless appearance, komokiaceans were frequently ignored or overlooked until they formal description in 1977. The most recent taxonomy places the Komokiacea within the Foraminifera based on general morphological features. To examine their taxonomic position at the molecular level, we analysed the SSU rDNA sequences of two species, Normanina conferta and Septuma ocotillo, obtained either with specific foraminiferal or universal eukaryotic primers. Many different sequences resulted from this investigation but none of them could clearly be attributed to komokiaceans. Although our study failed to confirm univocally that Komokiacea are foraminiferans, it revealed a huge eukaryotic richness associated with these organisms, comparable with the richness in the overall surrounding sediment. These observations suggest strongly that komokiaceans, and probably many other large testate protists, provide a habitat structure for a large spectrum of eukaryotes, significantly contributing to maintaining the biodiversity of micro- and meiofaunal communities in the deep sea.

Lecroq, Beatrice; Gooday, Andrew John

2009-01-01

275

The level of knowledge about the planning of training process of female engaged in recreational fitness  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of the study was to determine the level of knowledge about the planning of training process of female engaged in recreational fitness. The main method of investigation was questioning. The study involved 100 female aged 16-47 years engaged in fitness in three fitness centers in Gdansk and Sopot. The general level of knowledge of the planning of training process and its relationship with age, training experience and level of education was revealed.

Jagiello Wladyslaw

2011-07-01

276

The level of knowledge about the planning of training process of female engaged in recreational fitness  

OpenAIRE

The aim of the study was to determine the level of knowledge about the planning of training process of female engaged in recreational fitness. The main method of investigation was questioning. The study involved 100 female aged 16-47 years engaged in fitness in three fitness centers in Gdansk and Sopot. The general level of knowledge of the planning of training process and its relationship with age, training experience and level of education was revealed.

Jagiello Wladyslaw; Jagiello Marina.; Kozina Zh.L.

2011-01-01

277

Antimicrobial resistance profiling and molecular subtyping of Campylobacter spp. from processed turkey  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Campylobacter is a major cause of human disease worldwide and poultry are identified as a significant source of this pathogen. Most disease in humans is associated with the consumption of contaminated poultry or cross-contamination with other foods. The primary drugs of choice for treatment of human campylobacteriosis include erythromycin and ciprofloxacin. In this study, we investigated the prevalence of resistance to erythromycin and ciprofloxacin in Campylobacter isolates recovered from turkey carcasses at two processing plants in the Upper Midwest US. Further analysis of a subset of isolates was carried out to assess resistance and genotype profiles. Results Campylobacter isolates from plant A (n = 439; including 196 C. coli and 217 C. jejuni and plant B (n = 362, including 281 C. coli and 62 C. jejuni were tested for susceptibility to ciprofloxacin and erythromycin using agar dilution. C. coli were more frequently resistant than C. jejuni in both plants, including resistance to ciprofloxacin (28% of C. jejuni and 63% of C. coli, plant B; and 11% of C. coli, plant A. Erythromycin resistance was low among C. jejuni (0% plant A and 0.3% plant B compared to C. coli (41%, plant A and 17%, plant B. One hundred resistant and susceptible isolates were selected for additional antimicrobial susceptibility testing, restriction fragment length polymorphism analysis of the flaA gene (fla typing, and pulsed-field gel electrophoresis (PFGE. Fla-PFGE types obtained (n = 37 were associated with a specific plant with the exception of one type that was isolated from both plants. C. coli isolates (n = 65 were grouped into 20 types, while C. jejuni isolates (n = 35 were grouped into 17 types. Most isolates with identical fla-PFGE patterns shared identical or very similar antimicrobial resistance profiles. PFGE alone and composite analysis using fla-PFGE with resistance profiles separated C. jejuni and C. coli into distinct groups. Conclusion Ciprofloxacin and erythromycin resistance in Campylobacter recovered from processed turkey occurred more frequently among C. coli than C. jejuni. Fla-PFGE types were associated with a particular species, antimicrobial resistance profiles, and a specific plant. Molecular subtyping in this study provided more information about the relationships among antimicrobial-resistant Campylobacter at the processing level.

Sherwood Julie S

2009-09-01

278

Symmetry Breaking in NMR Spectroscopy: The Elucidation of Hidden Molecular Rearrangement Processes  

Directory of Open Access Journals (Sweden)

Full Text Available Variable-temperature NMR spectroscopy is probably the most convenient and sensitive technique to monitor changes in molecular structure in solution. Rearrangements that are rapid on the NMR time-scale exhibit simplified spectra, whereby non-equivalent nuclear environments yield time-averaged resonances. At lower temperatures, when the rate of exchange is sufficiently reduced, these degeneracies are split and the underlying “static” molecular symmetry, as seen by X-ray crystallography, becomes apparent. Frequently, however, such rearrangement processes are hidden, even when they become slow on the NMR time-scale, because the molecular point group remains unchanged. Judicious symmetry breaking, such as by substitution of a molecular fragment by a similar, but not identical moiety, or by the incorporation of potentially diastereotopic (chemically non-equivalent nuclei, allows the elucidation of the kinetics and energetics of such processes. Examples are chosen that include a wide range of rotations, migrations and other rearrangements in organic, inorganic and organometallic chemistry.

Michael J. McGlinchey

2014-08-01

279

Managing the Bologna Process at the European Level: Institution and Actor Dynamics  

Science.gov (United States)

This article analyses the work of the Bologna Follow Up Group as the main institution of the Bologna Process and the perceptions of the policy actors involved concerning the character of the process in terms of its functioning in contrast to similar multi-level multi-actor European processes, its modes of communication and consensus seeking, as…

Lazetic, Predrag

2010-01-01

280

Model of the photoexcitation processes of a two-level molecule coherently coupled to an optical antenna.  

Science.gov (United States)

We theoretically investigate photoexcitation processes of a two-level molecular system coherently coupled with an antenna system having a significant dissipation. The auxiliary antenna enables the whole system to exhibit anomalous optical effects by controlling the coupling with the molecule. For example, in the weak excitation regime, the quantum interference yields a distinctive energy transparency through the antenna, which drastically reduces the energy dissipation. On the other hand, in the strong excitation regime, a population inversion of the two-level molecule appears due to the nonlinear effect. Both phenomena can be explained by regarding the antenna and molecule as one quantum-mechanically coupled system. Such an approach drives further research to exploit the full potential of the coupled systems. PMID:23599121

Nakatani, Masatoshi; Nobuhiro, Atsushi; Yokoshi, Nobuhiko; Ishihara, Hajime

2013-06-01

281

An isomerization-induced cage-breaking process in a molecular glass former below Tg  

International Nuclear Information System (INIS)

A recent experimental [P. Karageorgiev, D. Neher, B. Schulz, B. Stiller, U. Pietsch, M. Giersig, L. Brehmer, Nature Mater. 4, 699 (2005)] study has found liquidlike diffusion below the glass-transition temperature in azobenzene-containing materials under irradiation. This result suggests that the isomerization-induced massive mass transport that leads to surface relief gratings formation in these materials, is induced by this huge increase of the matrix diffusion coefficient around the probe. In order to investigate the microscopic origin of the increase of the diffusion, we use molecular dynamics simulations of the photoisomerization of probe dispersed red 1 molecules dispersed inside a glassy molecular matrix. Results show that the increased diffusion is due to an isomerization-induced cage-breaking process. A process that explains the induced cooperative motions recently observed in these photoactive materials.

282

Advice concerning the advantages of a reference incinerator for low-level and intermediate-level radioactive waste processing  

International Nuclear Information System (INIS)

In this report, an inventory is presented of new incinerators and flue gas filters used in low and intermediate-level radioactive waste combustion. It is argued that a 'reference equipment' for the combustion of solid and liquid low- and intermediate-level wastes best meets existing Dutch radiation protection standards. A cost-benefit analysis of such an equipment is given including annual costs of investment, capital and exploration. A separate combustion process of organic liquids and carrions is considered finally. (G.J.P.)

283

Acceleration of Early-Photon Fluorescence Molecular Tomography with Graphics Processing Units  

OpenAIRE

Fluorescence molecular tomography (FMT) with early-photons can improve the spatial resolution and fidelity of the reconstructed results. However, its computing scale is always large which limits its applications. In this paper, we introduced an acceleration strategy for the early-photon FMT with graphics processing units (GPUs). According to the procedure, the whole solution of FMT was divided into several modules and the time consumption for each module is studied. In this strategy, two most...

Wang, Xin; Zhang, Bin; Cao, Xu; Liu, Fei; Luo, Jianwen; Bai, Jing

2013-01-01

284

Molecular simulation study on sorption and diffusion processes in polymeric pervaporation membrane materials  

OpenAIRE

Abstract Since MD simulations of membrane separation processes of aqueous/organic solutions lead to reasonable results that are in good agreement with experimental investigations an approach has been made to apply this method also for organic/organic membrane separation. In this connection the separation of a model feed mixture of 20 wt.-% benzene and 80 wt.-% n-heptane with dense amorphous polymer membranes was simulated utilising molecular modelling techniques. Special modificati...

Hofmann, Dieter; Schepers, Claudia

2006-01-01

285

Simulating picosecond x-ray diffraction from shocked crystals using post-processing molecular dynamics calculations  

OpenAIRE

Calculations of the patterns of x-ray diffraction from shocked crystals derived from the results of non-equilibrium molecular dynamics (NEMD) simulations are presented. The atomic coordinates predicted from the NEMD simulations combined with atomic form factors are used to generate a discrete distribution of electron density. A fast Fourier transform (FFT) of this distribution provides an image of the crystal in reciprocal space, which can be further processed to produce quantitative simulate...

Kimminau, G.; Nagler, B.; Higginbotham, A.; Murphy, Wj; Park, N.; Hawreliak, J.; Kadau, K.; Germann, Tc; Bringa, Em; Kalantar, Dh; Lorenzana, He; Remington, Ba; Wark, Js

2008-01-01

286

Ships: High-level process simulation for VLSI (Very Large Scale Integrated) manufacturing  

Science.gov (United States)

Very large scale integration fabrication is a complex set of operations set within a rapidly changing technology environment. It is subject to chance variations in process parameters, poor understanding and control of many parameters, and subtle interactions between them. At the same time, processing times and costs are increasing. The natural side-effect of these is that IC manufactures must require more evidence that the predicted and actual process characteristics will be within a tight tolerance. The prevailing means to verify process performance is through simulation. Unfortunately, while traditional process simulation tools such as SUPREM III have become pervasive in the IC industry as design aides for process development, they are not suited to the problems of manufacturing-level process simulation. What is required is a high-level process simulation tool that can introduce abstractions that reduce complexity and algorithms that reduce simulation costs. We have built such a tool called SHIPS, which stands for Stanford High-Level Incremental Process Simulator. The SHIPS tool provides a high-level process description language, a structured user-interface, and a new simulation algorithm for reducing the number of modules that must be simulated in analyzing the manufacturability of a process.

Leeke, Steven D.; Saraswat, Krishna

1987-02-01

287

Steered molecular dynamics simulations on the "tail helix latch" hypothesis in the gelsolin activation process.  

Science.gov (United States)

The molecular basis of the "tail helix latch" hypothesis in the gelsolin activation process has been studied by using the steered molecular dynamics simulations. In the present nanosecond scale simulations, the tail helix of gelsolin was pulled away from the S2 binding surface, and the required forces were calculated, from which the properties of binding between the tail helix and S2 domain and their dynamic unbinding processes were obtained. The force profile provides a detailed rupture mechanism that includes six major unbinding steps. In particular, the hydrogen bonds formed between Arg-207 and Asp-744 and between Arg-221 and Leu-753 are of the most important interaction pairs. The two hydrogen bond "clamps" stabilize the complex. The subsequent simulation on Arg-207-Ala (R207A) mutation of gelsolin indicated that this mutation facilitates the unbinding of the tail helix and that the contribution of the hydrogen bond between Arg-207 and Asp-744 to the binding is more than 50%, which offers a new clue for further mutagenesis study on the activation mechanism of gelsolin. Surrounding water molecules enhance the stability of the tail helix and facilitate the rupture process. Additionally, temperature also has a significant effect on the conformation of the arginine and arginine-related interactions, which revealed the molecular basis of the temperature dependence in gelsolin activation. PMID:12124262

Cheng, Feng; Shen, Jianhua; Luo, Xiaomin; Jiang, Hualiang; Chen, Kaixian

2002-01-01

288

All-dry processible and PAG-attached molecular glasses for improved lithographic performance  

Science.gov (United States)

As the semiconductor industry moves forward, resolution limits are being pushed to the sub-30 nm regime. In order to meet these demands, radical new resist design and processes must be explored. We have developed a molecular glass system for all-dry processing conditions. Physical vapor deposition (PVD) has been used for film formation onto silicon wafers. PVD deposits a uniform film of controlled thickness free from impurities that are often introduced by casting solvents used in traditional spin coating methods. Thermal development is used as an alternative to processing in solvents in order to prevent resist swelling and pattern collapse by capillary forces. The deposited molecule is designed to crosslink upon E-beam irradiation without additives, and therefore form a homogeneous, single component film. PAG-attached molecular glasses have been synthesized in order to promote film homogeneity as well. By tethering PAG directly to the molecular glass core, issues such as PAG aggregation can be remedied. Acid migration, which increases blur and LER, can also be hindered.

Krysak, Marie; Kolb, Tristan; Neuber, Christian; Schmidt, Hans-Werner; Ober, Christopher K.

2010-04-01

289

Toxic effects of pesticide mixtures at a molecular level: Their relevance to human health  

International Nuclear Information System (INIS)

Highlights: ? Toxic effects of pesticide mixtures can be independent, dose addition or interaction. ? Metabolic interactions involve inhibition or induction of detoxifying enzymes. ? Organophosphates can potentiate pyrethroid, carbaryl and triazine toxicity. ? Synergism occurs when two active pesticides elicit greater than additive toxicity. ? Endocrine disruptors have the potential for additivity rather than synergism. - Abstract: Pesticides almost always occur in mixtures with other ones. The toxicological effects of low-dose pesticide mixtures on the human health are largely unknown, although there are growing concerns about their safety. The combined toxicological effects of two or more components of a pesticide mixture can take one of three forms: independent, dose addition or interaction. Not all mixtures of pesticides with similar chemical structures produce additive effects; thus, if they act on multiple sites their mixtures may produce different toxic effects. The additive approach also fails when evaluating mixtures that involve a secondary chemical that changes the toxicokinetics of the pesticide as a result of its increased activation or decreased detoxification, which is followed by an enhanced or reduced toxicity, respectively. This review addresses a number of toxicological interactions of pesticide mixtures at a molecular level. Examples of such interactions include the postulated mechanisms for the potentiation of pyrethroid, carbaryl and triazine herbicides toxicity by organophosphates; how the toxicity of some organophosphates can be potentiated by other organophosphates or by previous exposure to organochlorines; the synergism between pyrethroid and carbamate compounds and the antagonism between triazine herbicides and prochloraz. Particular interactions are also addressed, such as those of pesticides acting as endocrine disruptors, the cumulative toxicity of organophosphates and organochlorines resulting in estrogenic effects and the promotion of organophosphate-induced delayed polyneuropathy

290

Homology modeling, molecular dynamics and atomic level interaction study of snake venom 5' nucleotidase.  

Science.gov (United States)

5' Nucleotidase (5' NUC) is a ubiquitously distributed enzyme known to be present in snake venoms (SV) that is responsible primarily for causing dysregulation of physiological homeostasis in humans by inducing anticoagulant effects and by inhibiting platelet aggregation. It is also known to act synergistically with other toxins to exert a more pronounced anti-coagulant effect during envenomation. Its structural and functional role is not yet ascertained clearly. The 3D structure of snake venom 5' nucleotidase (SV-5' NUC) is not yet known and was predicted by us for the first time using a comparative homology modeling approach using Demansia vestigiata protein sequence. The accuracy and stability of the predicted SV-5' NUC structure were validated using several computational approaches. Key interactions of SV-5' NUC were studied using experimental studies/molecular docking analysis of the inhibitors vanillin, vanillic acid and maltol. All these inhibitors were found to dock favorably following pharmacologically relevant absorption, distribution, metabolism and excretion (ADME) profiles. Further, atomic level docking interaction studies using inhibitors of the SV-5' NUC active site revealed amino acid residues Y65 and T72 as important for inhibitor-(SV-5' NUC) interactions. Our in silico analysis is in good agreement with experimental inhibition results of SV-5' NUC with vanillin, vanillic acid and maltol. The present study should therefore play a guiding role in the experimental design of new SV-5' NUC inhibitors for snake bite management. We also identified a few pharmacophoric features essential for SV-5' NUC inhibitory activity that can be utilized further for the discovery of putative anti-venom agents of therapeutic value for snake bite management. PMID:24567162

Arafat, A Syed Yasir; Arun, A; Ilamathi, M; Asha, J; Sivashankari, P R; D'Souza, Cletus J M; Sivaramakrishnan, V; Dhananjaya, B L

2014-03-01

291

Towards system-level understanding of baculovirus host cell interactions: from molecular fundamental studies to large-scale proteomics approaches  

Directory of Open Access Journals (Sweden)

Full Text Available Baculoviruses are insect viruses extensively exploited as eukaryotic protein expression vectors. Molecular biology studies have provided exciting discoveries on virus-host interactions, but the application of omic high throughput techniques on the baculovirus-insect cell system has been hampered by the lack of host genome sequencing. While a broader, systems level analysis of biological responses to infection is urgently needed, recent advances on proteomic studies have yielded new insights on the impact of infection on the host cell. These works are reviewed and critically assessed in the light of current biological knowledge of the molecular biology of baculoviruses and insect cells.

FranciscaMonteiro

2012-11-01

292

Molecular level alignment and work function change of dimethyl disulfide physisorbed thin films on Au(1 1 1)  

Science.gov (United States)

The formation and the electronic properties of a dimethyl-disulfide (DMDS) thin film adsorbed at low temperature on the Au(1 1 1) surface has been studied by means of Ultraviolet Photoemission Spectroscopy. The dependence of the binding energy of the molecular states as a function of coverage has been analyzed and compared to the corresponding work function change. A deviation from the expected rule for the molecular level alignment is observed and attributed to the differences between local and average work function. The effect of a buffer thiolated monolayer, obtained by dosing DMDS at room temperature, on the evolution of the interface electronic properties is also analyzed and discussed.

De Renzi, Valentina

2007-07-01

293

Fixation of radioactive wastes in glass by a process of molecular stuffing  

International Nuclear Information System (INIS)

Research on a process for adding dopants to high-silica porous glass at relatively low temperatures (0C) (Molecular Stuffing Process) has led to a method suitable for the storage of radioactive waste materials. Glass produced by this method has a high concentration of waste in the interior and is free of this waste in a thick surface layer. Silica content is above 75% in the core and above 90 mole % in the surface. The glass exhibits extremely high chemical durability and low diffusion rates for the waste

294

R-Matrix Theory of Atomic Collisions Application to Atomic, Molecular and Optical Processes  

CERN Document Server

Commencing with a self-contained overview of atomic collision theory, this monograph presents recent developments of R-matrix theory and its applications to a wide-range of atomic molecular and optical processes. These developments include electron and photon collisions with atoms, ions and molecules required in the analysis of laboratory and astrophysical plasmas, multiphoton processes required in the analysis of superintense laser interactions with atoms and molecules and positron collisions with atoms and molecules required in antimatter studies of scientific and technologial importance. Basic mathematical results and general and widely used R-matrix computer programs are summarized in the appendices.

Burke, Philip George

2011-01-01

295

Role of molecular dynamics on descriptions of shock-front processes  

International Nuclear Information System (INIS)

By means of a computational approach based on classical molecular dynamics, we can begin to form a realistic picture of shock-induced processes occurring at the shock front and resulting from the detailed, violent motion associated with shock motion on an atomic scale. Prototype studies of phase transitions will be discussed. We will also examine the interaction of the shock front with defects, surfaces, voids, and inclusions, and across grain boundaries. We will focus on the critical question of how mechanical energy imparted to a condensed material by shock loading is converted to the activation energy required to overcome some initial energy barrier in an initiation process

296

Multiple Semantic Processes at Different Levels of Syntactic Hierarchy: Does the Higher-Level Process Proceed in Face of a Lower-Level Failure?  

Science.gov (United States)

Humans have special abilities in processing hierarchical, recursive structures. Here we investigated how an upcoming word embedded in a hierarchical structure is semantically integrated into the prior representation during sentence comprehension. Participants read Chinese sentences with a complex verb argument structure "subject…

Jiang, Xiaoming; Zhou, Xiaolin

2012-01-01

297

Molecular Level Insights into Heterogeneous Chlorine Activation in the Polluted Marine Boundary Layer  

Science.gov (United States)

Heterogeneous reactions arising from the interaction of sea salt aerosols with polluted air at populated coastal sites generate gaseous inorganic chlorine compounds that are photochemical precursors of highly reactive chlorine atoms. These chlorine atoms initiate chain reactions that lead to elevated ozone concentrations in urban coastal regions. We used transmission and attenuated total reflection Fourier transform infrared spectroscopy to study the heterogeneous reactions of nitrogen oxides and hydrogen chloride on silica substrates and reveal previously unrecognized mechanisms for the formation of nitryl chloride and nitrosyl chloride that could impact our interpretation of chlorine activation processes on aerosols in coastal population centers. In addition to supporting recent field measurements that found relatively high levels of nitryl chloride at coastal sites in the Southeast U.S., our results suggest that additional sources of active chlorine exist in these regions.

Raff, J. D.; Finlayson-Pitts, B. J.

2008-12-01

298

Studies on deformation mechanism and punch taper effects on nanoimprint processes by molecular dynamics  

International Nuclear Information System (INIS)

A molecular dynamics analysis model is proposed to study the effects of parameters on nanoimprint process, for example: taper angle, imprint depth and spring back. The nanoimprint process comprises one punch and one specimen at an isothermal state of 400K, while the deformed material is a copper FCC single crystal and the punch material is a nickel FCC single crystal. There were a total of 10,080 atoms in copper measuring 12.02 nm x 5.72 nm in length and height, respectively. There were a total of 4,200 atoms in nickel where the typical length and depth in punch tooth are 6.24 nm x 3.52 nm, respectively. Computer simulation codes based on Hamiltonian dynamics, periodical boundary conditions and Morse potential function were used to simulate the nanoimprint processes. By varying the punch taper angle and the imprinting depth, useful information for nanoimprint process has been obtained

299

The effect of molecular relaxation processes in air on the rise time of sonic booms  

Science.gov (United States)

A theory is developed to explain the effect of molecular relaxation processes on the rise time of sonic booms. To determine the rise time of sonic booms, both O2 and N2 relaxation processes must be included. The N2 relaxation process delays the shock pressure reaching the maximum pressure, and the O2 relaxation process causes a shock profile to have a gentle slope. The N2 relaxation controls the lower part of overpressure; the O2 relaxation controls the higher part. The constant rise time curves show that the rise times increase as the overpressures and humidity decrease. The present approach gives longer rise times than those acquired by Bass et al. for given shock overpressures.

Kang, Jongmin; Pierce, Allan D.

1990-01-01

300

Low-level wastewater treatment facility process control operational test report  

International Nuclear Information System (INIS)

This test report documents the results obtained while conducting operational testing of a new TK 102 level controller and total outflow integrator added to the NHCON software that controls the Low-Level Wastewater Treatment Facility (LLWTF). The test was performed with WHC-SD-CP-OTP 154, PFP Low-Level Wastewater Treatment Facility Process Control Operational Test. A complete test copy is included in appendix A. The new TK 102 level controller provides a signal, hereafter referred to its cascade mode, to the treatment train flow controller which enables the water treatment process to run for long periods without continuous operator monitoring. The test successfully demonstrated the functionality of the new controller under standard and abnormal conditions expected from the LLWTF operation. In addition, a flow totalizer is now displayed on the LLWTF outlet MICON screen which tallies the process output in gallons. This feature substantially improves the ability to retrieve daily process volumes for maintaining accurate material balances

301

Interdisciplinary Education to Integrate Pathology and Epidemiology: Towards Molecular and Population-Level Health Science  

OpenAIRE

In recent decades, epidemiology, public health, and medical sciences have been increasingly compartmentalized into narrower disciplines. The authors recognize the value of integration of divergent scientific fields in order to create new methods, concepts, paradigms, and knowledge. Herein they describe the recent emergence of molecular pathological epidemiology (MPE), which represents an integration of population and molecular biologic science to gain insights into the etiologies, pathogenesi...

Ogino, Shuji; King, Emily E.; Beck, Andrew H.; Sherman, Mark E.; Milner, Danny A.; Giovannucci, Edward

2012-01-01

302

The Henry Ford Production System: LEAN Process Redesign Improves Service in the Molecular Diagnostic Laboratory: A Paper from the 2008 William Beaumont Hospital Symposium on Molecular Pathology  

OpenAIRE

Accurate and timely molecular test results play an important role in patient management; consequently, there is a customer expectation of short testing turnaround times. Baseline data analysis revealed that the greatest challenge to timely result generation occurred in the preanalytic phase of specimen collection and transport. Here, we describe our efforts to improve molecular testing turnaround times by focusing primarily on redesign of preanalytic processes using the principles of LEAN pro...

Cankovic, Milena; Varney, Ruan C.; Whiteley, Lisa; Brown, Ron; D Angelo, Rita; Chitale, Dhananjay; Zarbo, Richard J.

2009-01-01

303

Benchmarking energy use in the paper industry: a benchmarking study on process unit level  

Energy Technology Data Exchange (ETDEWEB)

There are large differences between paper mills in, e.g. feedstock use and grades produced, but typical processes are similar in all mills. The aim of this study is to benchmark the specific energy consumption (SEC) of similar processes within different paper mills in order to identify energy improvement potentials at process level. We have defined improvement potentials as measures that can be taken at mill/process level under assumed fixed inputs and outputs. We were able to use industrial data on detailed process level, and we conducted energy benchmarking comparisons in 23 Dutch paper mills. We calculated average SECs per process step for different paper grades, and we were able to identify ranges in SECs between mills producing the same grade. We found significant opportunities for energy efficiency improvement in the wire and press section as well as in the drying section. The total energy improvement potential based on identified best practices in these sections was estimated at 5.4 PJ (or 15 % of the total primary energy use in the selected mills). Energy use in the other processes was found to be too dependent on quality and product specifications to be able to quantify improvement potentials. Our results emphasise that even a benchmark on detailed process level does not lead to clear estimations of energy improvement potentials without accounting for structural effects and without having a decent understanding of the process.

Laurijssen, J. [Centre of Competence Paper and Board, IJsselburcht 3, 6825 BS Arnhem (Netherlands); Faaij, A.; Worrell, E. [Copernicus Institute, Utrecht University, Van Unnikgebouw, Heidelberglaan 2, 3584 CS Utrecht (Netherlands)

2013-02-15

304

The level of knowledge about the planning of training process of males engaged in recreational fitness.  

OpenAIRE

The aim of the study was to determine the level of knowledge about the planning of training process of males engaged in recreational fitness. The main method of investigation was questioning. The study involved 100 males aged 16-47 years engaged in fitness in three fitness centers in Gdansk and Sopot. The general level of knowledge of the planning of training process and its relationship with age and training experience was revealed.

Jagiello, Wladyslaw; Vechorek Voycheh; Jagiello Marina.

2011-01-01

305

Information theory and signal transduction systems: from molecular information processing to network inference.  

Science.gov (United States)

Sensing and responding to the environment are two essential functions that all biological organisms need to master for survival and successful reproduction. Developmental processes are marshalled by a diverse set of signalling and control systems, ranging from systems with simple chemical inputs and outputs to complex molecular and cellular networks with non-linear dynamics. Information theory provides a powerful and convenient framework in which such systems can be studied; but it also provides the means to reconstruct the structure and dynamics of molecular interaction networks underlying physiological and developmental processes. Here we supply a brief description of its basic concepts and introduce some useful tools for systems and developmental biologists. Along with a brief but thorough theoretical primer, we demonstrate the wide applicability and biological application-specific nuances by way of different illustrative vignettes. In particular, we focus on the characterisation of biological information processing efficiency, examining cell-fate decision making processes, gene regulatory network reconstruction, and efficient signal transduction experimental design. PMID:24953199

Mc Mahon, Siobhan S; Sim, Aaron; Filippi, Sarah; Johnson, Robert; Liepe, Juliane; Smith, Dominic; Stumpf, Michael P H

2014-11-01

306

Molecular view of an electron transfer process essential for iron-sulfur protein biogenesis.  

Science.gov (United States)

Biogenesis of iron-sulfur cluster proteins is a highly regulated process that requires complex protein machineries. In the cytosolic iron-sulfur protein assembly machinery, two human key proteins--NADPH-dependent diflavin oxidoreductase 1 (Ndor1) and anamorsin--form a stable complex in vivo that was proposed to provide electrons for assembling cytosolic iron-sulfur cluster proteins. The Ndor1-anamorsin interaction was also suggested to be implicated in the regulation of cell survival/death mechanisms. In the present work we unravel the molecular basis of recognition between Ndor1 and anamorsin and of the electron transfer process. This is based on the structural characterization of the two partner proteins, the investigation of the electron transfer process, and the identification of those protein regions involved in complex formation and those involved in electron transfer. We found that an unstructured region of anamorsin is essential for the formation of a specific and stable protein complex with Ndor1, whereas the C-terminal region of anamorsin, containing the [2Fe-2S] redox center, transiently interacts through complementary charged residues with the FMN-binding site region of Ndor1 to perform electron transfer. Our results propose a molecular model of the electron transfer process that is crucial for understanding the functional role of this interaction in human cells. PMID:23596212

Banci, Lucia; Bertini, Ivano; Calderone, Vito; Ciofi-Baffoni, Simone; Giachetti, Andrea; Jaiswal, Deepa; Mikolajczyk, Maciej; Piccioli, Mario; Winkelmann, Julia

2013-04-30

307

Molecular view of an electron transfer process essential for iron–sulfur protein biogenesis  

Science.gov (United States)

Biogenesis of iron–sulfur cluster proteins is a highly regulated process that requires complex protein machineries. In the cytosolic iron–sulfur protein assembly machinery, two human key proteins—NADPH-dependent diflavin oxidoreductase 1 (Ndor1) and anamorsin—form a stable complex in vivo that was proposed to provide electrons for assembling cytosolic iron–sulfur cluster proteins. The Ndor1–anamorsin interaction was also suggested to be implicated in the regulation of cell survival/death mechanisms. In the present work we unravel the molecular basis of recognition between Ndor1 and anamorsin and of the electron transfer process. This is based on the structural characterization of the two partner proteins, the investigation of the electron transfer process, and the identification of those protein regions involved in complex formation and those involved in electron transfer. We found that an unstructured region of anamorsin is essential for the formation of a specific and stable protein complex with Ndor1, whereas the C-terminal region of anamorsin, containing the [2Fe-2S] redox center, transiently interacts through complementary charged residues with the FMN-binding site region of Ndor1 to perform electron transfer. Our results propose a molecular model of the electron transfer process that is crucial for understanding the functional role of this interaction in human cells. PMID:23596212

Banci, Lucia; Bertini, Ivano; Calderone, Vito; Ciofi-Baffoni, Simone; Giachetti, Andrea; Jaiswal, Deepa; Mikolajczyk, Maciej; Piccioli, Mario; Winkelmann, Julia

2013-01-01

308

Feedback, group-level processes, and systems approaches in human evolution.  

Science.gov (United States)

An explicit role for emergent group-level traits, social role diversification, and coordination makes good sense when thinking about human evolution. To most effectively understand these and other facets, we need to move toward an integrative model that assumes niche construction and encompasses positive feedback systems at individual, subgroup and larger group levels, demographic processes, and local ecologies. PMID:24970405

Fuentes, Agustin

2014-06-01

309

Processes of DNA condensation induced by multivalent cations: Approximate annealing experiments and molecular dynamics simulations  

International Nuclear Information System (INIS)

The condensation of DNA induced by spermine is studied by atomic force microscopy (AFM) and molecular dynamics (MD) simulation in this paper. In our experiments, an equivalent amount of multivalent cations is added to the DNA solutions in different numbers of steps, and we find that the process of DNA condensation strongly depends on the speed of adding cations. That is, the slower the spermine cations are added, the slower the DNA aggregates. The MD and steered molecular dynamics (SMD) simulation results agree well with the experimental results, and the simulation data also show that the more steps of adding multivalent cations there are, the more compact the condensed DNA structure will be. This investigation can help us to control DNA condensation and understand the complicated structures of DNA—cation complexes. (interdisciplinary physics and related areas of science and technology)

310

Processes of DNA condensation induced by multivalent cations: Approximate annealing experiments and molecular dynamics simulations  

Science.gov (United States)

The condensation of DNA induced by spermine is studied by atomic force microscopy (AFM) and molecular dynamics (MD) simulation in this paper. In our experiments, an equivalent amount of multivalent cations is added to the DNA solutions in different numbers of steps, and we find that the process of DNA condensation strongly depends on the speed of adding cations. That is, the slower the spermine cations are added, the slower the DNA aggregates. The MD and steered molecular dynamics (SMD) simulation results agree well with the experimental results, and the simulation data also show that the more steps of adding multivalent cations there are, the more compact the condensed DNA structure will be. This investigation can help us to control DNA condensation and understand the complicated structures of DNA—cation complexes.

Chai, Ai-Hua; Ran, Shi-Yong; Zhang, Dong; Jiang, Yang-Wei; Yang, Guang-Can; Zhang, Lin-Xi

2013-09-01

311

The early stage of deposition process for Fe-Cu magnetic multilayer systems: molecular dynamics simulation  

Science.gov (United States)

The deposition behaviour for a Fe-Cu magnetic multilayer system in an early stage of the deposition process was investigated by molecular dynamics (MD) simulation. Specifically, the steering effect was quantitatively investigated through extensive measurements of the trajectory, deposition flux and force of atoms near the artificially structured Fe or Cu step positioned on the Cu(0 0 1) or Fe(0 0 1) surface. Near the step edges of the planar structure at a low incident energy of 0.1 eV, the steering effect for the case of Fe/Cu(0 0 1) was observed more significantly than for Cu/Fe(0 0 1). Additionally, the mechanism of down-diffusion from the step was discussed and the corresponding energetic was calculated using the molecular statics method.

Lee, Soon-Gun; Chung, Yong-Chae

2009-07-01

312

The early stage of deposition process for Fe-Cu magnetic multilayer systems: molecular dynamics simulation  

International Nuclear Information System (INIS)

The deposition behaviour for a Fe-Cu magnetic multilayer system in an early stage of the deposition process was investigated by molecular dynamics (MD) simulation. Specifically, the steering effect was quantitatively investigated through extensive measurements of the trajectory, deposition flux and force of atoms near the artificially structured Fe or Cu step positioned on the Cu(0 0 1) or Fe(0 0 1) surface. Near the step edges of the planar structure at a low incident energy of 0.1 eV, the steering effect for the case of Fe/Cu(0 0 1) was observed more significantly than for Cu/Fe(0 0 1). Additionally, the mechanism of down-diffusion from the step was discussed and the corresponding energetic was calculated using the molecular statics method.

313

Isolation and Identification of Listeria monocytogenes in Processed Meat by a Combined Cultural-molecular Method  

Directory of Open Access Journals (Sweden)

Full Text Available The isolation and identification of Listeria monocytogenes in processed meat samples by a combined cultural-molecular method is described. It allows the identification of Listeria strains by means of a hybridization technique with a specific DNA probe directed to the listerial internalin gene. The specificity of this method was found to be 100% and sensitivity was as low as 1 CFU/2.5 g of food sample. A total of 278 meat samples were tested in comparison with PCR and conventional cultural assays. A total of 42 (15.4% L. monocytogenes were detected. PCR analysis gave 3 false negative results and culture failed to detect the Listeria in 5 cases. With this cultural-molecular method the identification and quantitative detection of L. monocytogenes were achieved within 36 hours and no false positive or negative tests were obtained, thus fitting most food industry requirements.

Angela Ingianni

2007-01-01

314

Broadening the horizon – level 2.5 of the HUPO-PSI format for molecular interactions  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Molecular interaction Information is a key resource in modern biomedical research. Publicly available data have previously been provided in a broad array of diverse formats, making access to this very difficult. The publication and wide implementation of the Human Proteome Organisation Proteomics Standards Initiative Molecular Interactions (HUPO PSI-MI format in 2004 was a major step towards the establishment of a single, unified format by which molecular interactions should be presented, but focused purely on protein-protein interactions. Results The HUPO-PSI has further developed the PSI-MI XML schema to enable the description of interactions between a wider range of molecular types, for example nucleic acids, chemical entities, and molecular complexes. Extensive details about each supported molecular interaction can now be captured, including the biological role of each molecule within that interaction, detailed description of interacting domains, and the kinetic parameters of the interaction. The format is supported by data management and analysis tools and has been adopted by major interaction data providers. Additionally, a simpler, tab-delimited format MITAB2.5 has been developed for the benefit of users who require only minimal information in an easy to access configuration. Conclusion The PSI-MI XML2.5 and MITAB2.5 formats have been jointly developed by interaction data producers and providers from both the academic and commercial sector, and are already widely implemented and well supported by an active development community. PSI-MI XML2.5 enables the description of highly detailed molecular interaction data and facilitates data exchange between databases and users without loss of information. MITAB2.5 is a simpler format appropriate for fast Perl parsing or loading into Microsoft Excel.

Cusick Michael E

2007-10-01

315

Molecular level assessment of thermal transport and thermoelectricity in materials: From bulk alloys to nanostructures  

Science.gov (United States)

The ability to manipulate material response to dynamical processes depends on the extent of understanding of transport properties and their variation with chemical and structural features in materials. In this perspective, current work focuses on the thermal and electronic transport behavior of technologically important bulk and nanomaterials. Strontium titanate is a potential thermoelectric material due to its large Seebeck coefficient. Here, first principles electronic band structure and Boltzmann transport calculations are employed in studying the thermoelectric properties of this material in doped and deformed states. The calculations verified that excessive carrier concentrations are needed for this material to be used in thermoelectric applications. Carbon- and boron nitride-based nanomaterials also offer new opportunities in many applications from thermoelectrics to fast heat removers. For these materials, molecular dynamics calculations are used to evaluate lattice thermal transport. To do this, first, an energy moment term is reformulated for periodic boundary conditions and tested to calculate thermal conductivity from Einstein relation in various systems. The influences of the structural details (size, dimensionality) and defects (vacancies, Stone-Wales defects, edge roughness, isotopic disorder) on the thermal conductivity of C and BN nanostructures are explored. It is observed that single vacancies scatter phonons stronger than other type of defects due to unsatisfied bonds in their structure. In pristine states, BN nanostructures have 4-6 times lower thermal conductivity compared to C counterparts. The reason of this observation is investigated on the basis of phonon group velocities, life times and heat capacities. The calculations show that both phonon group velocities and life times are smaller in BN systems. Quantum corrections are also discussed for these classical simulations. The chemical and structural diversity that could be attained by mixing hexagonal boron nitride and graphene provide further avenues for tuning thermal and electronic properties. In this work, the thermal conductivity of hybrid graphene/hexagonal-BN structures: stripe superlattices and BN (graphene) dots embedded in graphene (BN) are studied. The largest reduction in thermal conductivity is observed at 50% chemical mixture in dot superlattices. The dot radius appears to have little effect on the magnitude of reduction around large concentrations while smaller dots are more influential at dilute systems.

Kinaci, Alper

316

SCRUB-PA: A Multi-Level Multi-Dimensional Anonymization Tool for Process Accounting  

CERN Document Server

In the UNIX/Linux environment the kernel can log every command process created by every user using process accounting. This data has many potential uses, including the investigation of security incidents. However, process accounting data is also sensitive since it contains private user information. Consequently, security system administrators have been hindered from sharing these logs. Given that many interesting security applications could use process accounting data, it would be useful to have a tool that could protect private user information in the logs. For this reason we introduce SCRUB-PA, a tool that uses multi-level multi-dimensional anonymization on process accounting log files in order to provide different levels of privacy protection. It is our goal that SCRUB-PA will promote the sharing of process accounting logs while preserving privacy.

Luo, K; Li, Y; Slagell, A J; Yurcik, W; Ermopoulos, Charis; Li, Yifan; Luo, Katherine; Slagell, Adam; Yurcik, William

2006-01-01

317

West Valley demonstration project: alternative processes for solidifying the high-level wastes  

Energy Technology Data Exchange (ETDEWEB)

In 1980, the US Department of Energy (DOE) established the West Valley Solidification Project as the result of legislation passed by the US Congress. The purpose of this project was to carry out a high level nuclear waste management demonstration project at the Western New York Nuclear Service Center in West Valley, New York. The DOE authorized the Pacific Northwest Laboratory (PNL), which is operated by Battelle Memorial Institute, to assess alternative processes for treatment and solidification of the WNYNSC high-level wastes. The Process Alternatives Study is the suject of this report. Two pretreatment approaches and several waste form processes were selected for evaluation in this study. The two waste treatment approaches were the salt/sludge separation process and the combined waste process. Both terminal and interim waste form processes were studied.

Holton, L.K.; Larson, D.E.; Partain, W.L.; Treat, R.L.

1981-10-01

318

Process description and plant design for preparing ceramic high-level waste forms  

International Nuclear Information System (INIS)

The ceramics process flow diagram has been simplified and upgraded to utilize only two major processing steps - fluid-bed calcination and hot isostatic press consolidating. Full-scale fluid-bed calcination has been used at INEL to calcine high-level waste for 18 y; and a second-generation calciner, a fully remotely operated and maintained calciner that meets ALARA guidelines, started calcining high-level waste in 1982. Full-scale hot isostatic consolidation has been used by DOE and commercial enterprises to consolidate radioactive components and to encapsulate spent fuel elements for several years. With further development aimed at process integration and parametric optimization, the operating knowledge of full-scale demonstration of the key process steps should be rapidly adaptable to scale-up of the ceramic process to full plant size. Process flowsheets used to prepare ceramic and glass waste forms from defense and commercial high-level liquid waste are described. Preliminary layouts of process flow diagrams in a high-level processing canyon were prepared and used to estimate the preliminary cost of the plant to fabricate both waste forms. The estimated costs for using both options were compared for total waste management costs of SRP high-level liquid waste. Using our design, for both the ceramic and glass plant, capital and operating costs are essentially the same for both defense and commercial wastes, but total waste management costs are calculated to be significantly less for defense wastes using the ceramic option. It is concluded from this and other studies that the ceramic form may offer important advantages over glass in leach resistance, waste loading, density, and process flexibility. Preliminary economic calculations indicate that ceramics must be considered a leading candidate for the form to immobilize high-level wastes

319

Characterization of majority and minority carrier deep levels in p-type GaN:Mg grown by molecular beam epitaxy using deep level optical spectroscopy  

International Nuclear Information System (INIS)

Deep level defects in p-type GaN:Mg grown by molecular beam epitaxy were characterized using steady-state photocapacitance and deep level optical spectroscopy (DLOS). Low frequency capacitance measurements were used to alleviate dispersion effects stemming from the deep Mg acceptor. Use of DLOS enabled a quantitative survey of both deep acceptor and deep donor levels, the latter being particularly important due to the limited understanding of minority carrier states for p-type GaN. Simultaneous electron and hole photoemissions resulted in a convoluted deep level spectrum that was decoupled by emphasizing either majority or minority carrier optical emission through control of the thermal filling time conditions. In this manner, DLOS was able to resolve and quantify the properties of deep levels residing near both the conduction and valence bandedges in the same sample. Bandgap states through hole photoemission were observed at Ev+3.05 eV, Ev+3.22 eV and Ev+3.26 eV. Additionally, DLOS revealed levels at Ec-3.24 eV and Ec-2.97 eV through electron emission to the conduction band with the former attributed to the Mg acceptor itself. The detected deep donor concentration is less than 2% of activated [Mg] and demonstrates the excellent quality of the film

320

Molecular reordering processes on ice (0001) surfaces from long timescale simulations  

CERN Document Server

We report results of long timescale adaptive kinetic Monte Carlo simulations aimed at identifying possible molecular reordering processes on both proton-disordered and ordered (Fletcher) basal plane (0001) surfaces of hexagonal ice. The simulations are based on a force field for flexible molecules and span a time interval of up to 50 {\\mu}s at a temperature of 100 K, which represents a lower bound to the temperature range of Earth's atmosphere. Additional calculations using both density functional theory and an ab initio based polarizable potential function are performed to test and refine the force field predictions. Several distinct processes are found to occur readily even at this low temperature, including concerted reorientation (flipping) of neighboring surface molecules, which changes the pattern of dangling H-atoms, and the formation of interstitial defects by the downwards motion of upper-bilayer molecules. On the proton-disordered surface, one major surface roughening process is observed that signif...

Pedersen, Andreas; Karssemeijer, Leendertjan; Cuppen, Herma; Jónsson, Hannes

2014-01-01

321

Energy conversion processes based on molecular excited states: Progress report, August 1, 1987-July 31, 1988  

International Nuclear Information System (INIS)

The first of the two interwoven threads of our DOE-supported research efforts include studies on the preparation and photochemical properties of transition metal complexes which have metal to ligand charge transfer excited states. In sight is being gained into the electronic structure and photochemical and photophysical properties of these excited states. The second emphasis in our work has been on the preparation and characterization of thin polymeric films which contain these complexes. The goal is to learn how to vary the underlying microstructure as a basis for energy conversion applications at the molecular level. 10 refs

322

Thickness control of molecular beam epitaxy grown layers at the 0.01–0.1 monolayer level  

International Nuclear Information System (INIS)

Electron tunnelling through semiconductor tunnel barriers is exponentially sensitive to the thickness of the barrier layer, and in the most common system, the AlAs tunnel barrier in GaAs, a one monolayer variation in thickness results in a 300% variation in the tunnelling current for a fixed bias voltage. We use this degree of sensitivity to demonstrate that the level of control at 0.06 monolayer can be achieved in the growth by molecular beam epitaxy, and the geometrical variation of layer thickness across a wafer at the 0.01 monolayer level can be detected. (paper)

323

Cellular and molecular mechanism study of declined intestinal transit function in the cholesterol gallstone formation process of the guinea pig.  

Science.gov (United States)

The aim of this study was to investigate the cellular and molecular mechanisms of declined intestinal transit (IT) function in the cholesterol gallstone (CG) formation process. Forty guinea pigs were divided into an experimental group (EG) and a control group (CoG), and the reverse transcription-polymerase chain reaction (RT-PCR) was performed for the analysis of c-kit and stem cell factor (scf) mRNA expression in the small bowel. In addition, immunofluorescence staining and confocal laser microscopy were performed for the observation of the changes in the number of interstitial cells of Cajal (ICCs) in the terminal ileum of each group. RT-PCR showed that, compared with the CoG, the intestinal c-kit and scf mRNA expression levels in the EG were significantly decreased; the average positive area of ICCs in the ileum in the EG was also significantly reduced. During the diet-induced CG formation procedure, the c-kit and scf mRNA expression levels in the small intestine decreased and the number of ICCs decreased. Inhibition of the c-kit/scf pathway may be involved in the declined IT function during the CG formation process. PMID:25289052

Fan, Ying; Wu, Shuodong; Yin, Zhenhua; Fu, Bei-Bei

2014-11-01

324

Waste processing complex for low- and intermediate level radioactive wastes in the NPP Kursk  

International Nuclear Information System (INIS)

For the NPP Kursk NUKEM Technologies GmbH plans a waste processing facility for solid low-level and intermediate-level radioactive waste on site. The concept of the facility includes besides the conditioning of solid waste by sorting, fragmentation, thermal treatment and high-pressure compacting also decontamination of metallic low-level wastes (specific total activity up to 10E6 Bq/kg) and intermediate-level wastes (up to 10E10 Bq/kg). The logistic concept of the material throughput allows a flexible utilization of the decontamination facility dependent on material, geometry and contamination.

325

Adaptation and learning of molecular networks as a description of cancer development at the systems-level: Potential use in anti-cancer therapies  

CERN Document Server

There is a widening recognition that cancer cells are products of complex developmental processes. Carcinogenesis and metastasis formation are increasingly described as systems-level, network phenomena. Here we propose that malignant transformation is a two-phase process, where an initial increase of system plasticity is followed by a decrease of plasticity at late stages of carcinogenesis as a model of cellular learning. We describe the hallmarks of increased system plasticity of early, tumor initiating cells, such as increased noise, entropy, conformational and phenotypic plasticity, physical deformability, cell heterogeneity and network rearrangements. Finally, we argue that the large structural changes of molecular networks during cancer development necessitate a rather different targeting strategy in early and late phase of carcinogenesis. Plastic networks of early phase cancer development need a central hit, while rigid networks of late stage primary tumors or established metastases should be attacked b...

Gyurko, David M; Modos, Dezso; Lenti, Katalin; Korcsmaros, Tamas; Csermely, Peter

2013-01-01

326

Mathematical models of non-linear phenomena, processes and systems: from molecular scale to planetary atmosphere  

CERN Document Server

This book consists of twenty seven chapters, which can be divided into three large categories: articles with the focus on the mathematical treatment of non-linear problems, including the methodologies, algorithms and properties of analytical and numerical solutions to particular non-linear problems; theoretical and computational studies dedicated to the physics and chemistry of non-linear micro-and nano-scale systems, including molecular clusters, nano-particles and nano-composites; and, papers focused on non-linear processes in medico-biological systems, including mathematical models of ferments, amino acids, blood fluids and polynucleic chains.

2013-01-01

327

Molecular and physiological basic processes in the context of radiation protection  

International Nuclear Information System (INIS)

The aim of this paper is an attempt to answer the question why accumulated knowledge on molecular basis of biological effects of ionizing radiation have not yet resulted in in sufficiently successful chemical radiation protection. In the past decade experimental results which demonstrated a direct regulatory role of some radicals in the main physiological processes such as vascular tone successfully emphasize the significance of old experimental results (the best protection can be achieved through physiological manipulations) connecting them to new data on free radical evolvement and the application of various free radical scavengers in radiation protection, which represents the most appropriate approach to the problem. (author)

328

Simulating Picosecond X-ray Diffraction from shocked crystals by Post-processing Molecular Dynamics Calculations  

Energy Technology Data Exchange (ETDEWEB)

Calculations of the x-ray diffraction patterns from shocked crystals derived from the results of Non-Equilibrium-Molecular-Dynamics (NEMD) simulations are presented. The atomic coordinates predicted by the NEMD simulations combined with atomic form factors are used to generate a discrete distribution of electron density. A Fast-Fourier-Transform (FFT) of this distribution provides an image of the crystal in reciprocal space, which can be further processed to produce quantitative simulated data for direct comparison with experiments that employ picosecond x-ray diffraction from laser-irradiated crystalline targets.

Kimminau, G; Nagler, B; Higginbotham, A; Murphy, W; Park, N; Hawreliak, J; Kadau, K; Germann, T C; Bringa, E M; Kalantar, D; Lorenzana, H; Remington, B; Wark, J

2008-06-19

329

News Note: Scientists identify molecular link between BRCA1 protein levels and obesity  

Science.gov (United States)

NCI researchers have defined a possible molecular link between breast cancer risk and obesity. New study results show that a protein called C-terminal binding protein (CtBP) acts to control a gene linked to breast cancer risk in rapidly growing cells by monitoring and responding to how the cells use and store energy (metabolic state).

330

MOLECULAR SIEVES AS CATALYSTS FOR METHANOL DEHYDRATION IN THE LPDMEtm PROCESS  

Energy Technology Data Exchange (ETDEWEB)

Several classes of molecular sieves were investigated as methanol dehydration catalysts for the LPDME{trademark} (liquid-phase dimethyl ether) process. Molecular sieves offer a number of attractive features as potential catalysts for the conversion of methanol to DME. These include (1) a wide range of acid strengths, (2) diverse architectures and channel connectivities that provide latitude for steric control, (3) high active site density, (4) well-investigated syntheses and characterization, and (5) commercial availability in some cases. We directed our work in two areas: (1) a general exploration of the catalytic behavior of various classes of molecular sieves in the LPDME{trademark} system and (2) a focused effort to prepare and test zeolites with predominantly Lewis acidity. In our general exploration, we looked at such diverse materials as chabazites, mordenites, pentasils, SAPOs, and ALPOs. Our work with Lewis acidity sought to exploit the structural advantages of zeolites without the interfering effects of deleterious Broensted sites. We used zeolite Ultrastable Y (USY) as our base material because it possesses a high proportion of Lewis acid sites. This work was extended by modifying the USY through ion exchange to try to neutralize residual Broensted acidity.

Andrew W. Wang

2002-04-01

331

Board-invited review: Sensitivity and responses of functional groups to feed processing methods on a molecular basis  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract In complex feed structures, there exist main chemical functional groups which are associated with nutrient utilization and availability and functionality. Each functional group has unique molecular structure therefore produce unique molecular vibration spectral profile. Feed processing has been used to improve nutrient utilization for many years. However, to date, there was little study on processing-induced changes of feed intrinsic structure and functional groups on a molecular basis within intact tissue. This is because limited research technique is available to study inherent structure on a molecular basis. Recently bioanalytical techniques: such as Synchrotron Infrared Microspectroscopy as well as Diffuse Reflectance Infrared Fourier Transform molecular spectroscopy have been developed. These techniques enable to detect molecular structure change within intact tissues. These techniques can prevent destruction or alteration of the intrinsic protein structures during processing for analysis. However, these techniques have not been used in animal feed and nutrition research. The objective of this review was show that with the advanced technique, sensitivity and responses of functional groups to feed processing on a molecular basis could be detected in my research team. These functional groups are highly associated with nutrient utilization in animals.

Yu Peiqiang

2012-12-01

332

Critical assessment of methods for treating airborne effluents from high-level waste solidification processes  

Energy Technology Data Exchange (ETDEWEB)

Off-gas treatment systems are reviewed for high-temperature processes which are being developed for the solidification of high-level liquid wastes from nuclear fuel reprocessing plants. A brief description of each of the processes is given and detailed analyses are made of the expected magnitudes of airborne effluent release rates from each system. The estimated release rates of the various processes are compared with present and anticipated regulatory limits. A number of recommendations are made for additional development studies to better understand and control certain airborne effluents from the solidification processes.

Christian, J.D.; Pence, D.T.

1977-06-01

333

Critical assessment of methods for treating airborne effluents from high-level waste solidification processes  

International Nuclear Information System (INIS)

Off-gas treatment systems are reviewed for high-temperature processes which are being developed for the solidification of high-level liquid wastes from nuclear fuel reprocessing plants. A brief description of each of the processes is given and detailed analyses are made of the expected magnitudes of airborne effluent release rates from each system. The estimated release rates of the various processes are compared with present and anticipated regulatory limits. A number of recommendations are made for additional development studies to better understand and control certain airborne effluents from the solidification processes

334

Site selection and characterization processes for deep geologic disposal of high level nuclear waste  

International Nuclear Information System (INIS)

In this paper, the major elements of the site selection and characterization processes used in the US high level waste program are discussed. While much of the evolution of the site selection and characterization processes have been driven by the unique nature of the US program, these processes, which are well defined and documented, could be used as an initial basis for developing site screening, selection, and characterization programs in other countries. Thus, this paper focuses more on the process elements than the specific details of the US program

335

Site selection and characterization processes for deep geologic disposal of high level nuclear waste  

Energy Technology Data Exchange (ETDEWEB)

In this paper, the major elements of the site selection and characterization processes used in the U. S. high level waste program are discussed. While much of the evolution of the site selection and characterization processes have been driven by the unique nature of the U. S. program, these processes, which are well-defined and documented, could be used as an initial basis for developing site screening, selection, and characterization programs in other countries. Thus, this paper focuses more on the process elements than the specific details of the U. S. program. (author). 3 refs., 2 tabs., 5 figs.

Costin, L.S. [Sandia National Labs., Albuquerque, NM (United States)

1997-12-31

336

Site selection and characterization processes for deep geologic disposal of high level nuclear waste  

International Nuclear Information System (INIS)

In this paper, the major elements of the site selection and characterization processes used in the U. S. high level waste program are discussed. While much of the evolution of the site selection and characterization processes have been driven by the unique nature of the U. S. program, these processes, which are well-defined and documented, could be used as an initial basis for developing site screening, selection, and characterization programs in other countries. Thus, this paper focuses more on the process elements than the specific details of the U. S. program. (author). 3 refs., 2 tabs., 5 figs

337

RECENT PROCESS AND EQUIPMENT IMPROVEMENTS TO INCREASE HIGH LEVEL WASTE THROUGHPUT AT THE DEFENSE WASTE PROCESSING FACILITY  

Energy Technology Data Exchange (ETDEWEB)

The Savannah River Site's (SRS) Defense Waste Processing Facility (DWPF) began stabilizing high level waste (HLW) in a glass matrix in 1996. Over the past few years, there have been several process and equipment improvements at the DWPF to increase the rate at which the high level waste can be stabilized. These improvements have either directly increased waste processing rates or have desensitized the process to upsets, thereby minimizing downtime and increasing production. Improvements due to optimization of waste throughput with increased HLW loading of the glass resulted in a 6% waste throughput increase based upon operational efficiencies. Improvements in canister production include the pour spout heated bellows liner (5%), glass surge (siphon) protection software (2%), melter feed pump software logic change to prevent spurious interlocks of the feed pump with subsequent dilution of feed stock (2%) and optimization of the steam atomized scrubber (SAS) operation to minimize downtime (3%) for a total increase in canister production of 12%. A number of process recovery efforts have allowed continued operation. These include the off gas system pluggage and restoration, slurry mix evaporator (SME) tank repair and replacement, remote cleaning of melter top head center nozzle, remote melter internal inspection, SAS pump J-Tube recovery, inadvertent pour scenario resolutions, dome heater transformer bus bar cooling water leak repair and new Infra-red camera for determination of glass height in the canister are discussed.

Odriscoll, R; Allan Barnes, A; Jim Coleman, J; Timothy Glover, T; Robert Hopkins, R; Dan Iverson, D; Jeff Leita, J

2008-01-15

338

RECENT PROCESS AND EQUIPMENT IMPROVEMENTS TO INCREASE HIGH LEVEL WASTE THROUGHPUT AT THE DEFENSE WASTE PROCESSING FACILITY  

International Nuclear Information System (INIS)

The Savannah River Site's (SRS) Defense Waste Processing Facility (DWPF) began stabilizing high level waste (HLW) in a glass matrix in 1996. Over the past few years, there have been several process and equipment improvements at the DWPF to increase the rate at which the high level waste can be stabilized. These improvements have either directly increased waste processing rates or have desensitized the process to upsets, thereby minimizing downtime and increasing production. Improvements due to optimization of waste throughput with increased HLW loading of the glass resulted in a 6% waste throughput increase based upon operational efficiencies. Improvements in canister production include the pour spout heated bellows liner (5%), glass surge (siphon) protection software (2%), melter feed pump software logic change to prevent spurious interlocks of the feed pump with subsequent dilution of feed stock (2%) and optimization of the steam atomized scrubber (SAS) operation to minimize downtime (3%) for a total increase in canister production of 12%. A number of process recovery efforts have allowed continued operation. These include the off gas system pluggage and restoration, slurry mix evaporator (SME) tank repair and replacement, remote cleaning of melter top head center nozzle, remote melter internal inspection, SAS pump J-Tube recovery, inadvertent pour scenario resolutions, dome heater transformer bus bar cooling water leak repair and new Infra-red camera for determinatir and new Infra-red camera for determination of glass height in the canister are discussed

339

Observation of unexpected energy levels in molecular hydrogen and ortho-para energy transfer  

International Nuclear Information System (INIS)

We report the observation of eight unexpected energy levels close to but clearly different from H2 B 1?u+ levels. In transitions involving these levels vacuum-ultraviolet transitions terminating in p-H2 levels are observed subsequent to two-photon Q(1) excitation X1?g+(v''=0)?EF 1?g+(v'=6) of o-H2. Several findings indicate that these strange levels may be a manifestation of electronically excited H4, which has been discussed in a number of theoretical contributions

340

Study the sensitivity of molecular functional groups to bioethanol processing in lipid biopolymer of co-products using DRIFT molecular spectroscopy  

Science.gov (United States)

To date, there is no study on bioethanol processing-induced changes in molecular structural profiles mainly related to lipid biopolymer. The objectives of this study were to: (1) determine molecular structural changes of lipid related functional groups in the co-products that occurred during bioethanol processing; (2) relatively quantify the antisymmetric CH 3 and CH 2 (ca. 2959 and 2928 cm -1, respectively), symmetric CH 3 and CH 2 (ca. 2871 and 2954 cm -1, respectively) functional groups, carbonyl C dbnd O ester (ca. 1745 cm -1) and unsaturated groups (CH attached to C dbnd C) (ca. 3007 cm -1) spectral intensities as well as their ratios of antisymmetric CH 3 to antisymmetric CH 2, and (3) illustrate the molecular spectral analyses as a research tool to detect for the sensitivity of individual moleculars to the bioethanol processing in a complex plant-based feed and food system without spectral parameterization. The hypothesis of this study was that bioethanol processing changed the molecular structure profiles in the co-products as opposed to original cereal grains. These changes could be detected by infrared molecular spectroscopy and will be related to nutrient utilization. The results showed that bioethanol processing had effects on the functional groups spectral profiles in the co-products. It was found that the CH 3-antisymmetric to CH 2-antisymmetric stretching intensity ratio was changed. The spectral features of carbonyl C dbnd O ester group and unsaturated group were also different. Since the different types of cereal grains (wheat vs. corn) had different sensitivity to the bioethanol processing, the spectral patterns and band component profiles differed between their co-products (wheat DDGS vs. corn DDGS). The multivariate molecular spectral analyses, cluster analysis and principal component analysis of original spectra (without spectral parameterization), distinguished the structural differences between the wheat and wheat DDGS and between the corn and corn DDGS in the antisymmetric and symmetric CH 3 and CH 2 spectral region (ca. 2994-2800 cm -1) and unsaturated group band region (3025-2996 cm -1). Further study is needed to quantify molecular structural changes in relation to nutrient utilization of lipid biopolymer.

Yu, Peiqiang

2011-11-01

341

Chronic alcohol consumption and intestinal thiamin absorption: effects on physiological and molecular parameters of the uptake process.  

Science.gov (United States)

Thiamin is essential for normal cellular functions, and its deficiency leads to a variety of clinical abnormalities. Humans and other mammals obtain the vitamin via intestinal absorption. The intestine is exposed to two sources of thiamin, a dietary and a bacterial (i.e., normal microflora of the large intestine) source. Chronic alcohol consumption is associated with thiamin deficiency, which is caused (in part) by inhibition in intestinal thiamin absorption. However, little is known about the physiological and molecular aspects of the intestinal thiamin uptake process that are affected by chronic alcohol use. To address these issues, we used rats fed an alcohol-liquid diet and human intestinal epithelial HuTu-80 cells chronically exposed to ethanol as model systems. The results showed that chronic alcohol feeding to rats led to a significant inhibition in carrier-mediated thiamin transport across both the jejunal brush-border membrane and basolateral membrane domains. This was associated with a significant reduction in level of expression of thiamin transporter-1 (THTR-1), but not THTR-2, at the protein and mRNA levels. Level of expression of the heterogenous nuclear RNA of THTR-1 in the intestine of alcohol-fed rats was also decreased compared with their pair-fed controls. Chronic alcohol feeding also caused a significant inhibition in carrier-mediated thiamin uptake in rat colon. Studies with HuTu-80 cells chronically exposed to ethanol also showed a significant inhibition in carrier-mediated thiamin uptake. This inhibition was associated with a reduction in level of expression of human THTR-1 and THTR-2 at the protein, mRNA, and transcriptional (promoter activity) levels. These studies demonstrate that chronic alcohol feeding inhibits intestinal thiamin absorption via inhibition of the individual membrane transport event across the polarized absorptive epithelial cells. Furthermore, the inhibition is, at least in part, mediated via transcriptional mechanism(s). PMID:20448146

Subramanya, Sandeep B; Subramanian, Veedamali S; Said, Hamid M

2010-07-01

342

Simulation for Nanoimprint Lithography Process Using Temperature Controlled Nonequilibrium Molecular Dynamics  

International Nuclear Information System (INIS)

Temperature is an essential process variable in NanoImprint Lithography(NIL) where the temperature varies between room temperature and above the glass transition temperature. To simulate NIL process, we employ both the Nose-Poincare method for temperature controlled Molecular Dynamics(MD) and force field for polymer material i.e. PolyMethyl MethAcrylate(PMMA), which is most widely selected as NIL resist. Nose-Poincare method, which convinces the conservation of Hamiltonian structure and time-reversal symmetry, overcomes the drawbacks inherent in the conventional methods such as Nose thermostat and Nose-Hoover thermostat. Thus, this method exhibits enhanced numerical stability even when the temperature fluctuation is large. To describe PMMA, we adopt the force field which account for bond stretch, bending, torsion, inversion, partial charge, and van der Waals energy

343

Induction and reversion process of molecular and cytological alterations after highly irradiated food ingestion in mice  

International Nuclear Information System (INIS)

The molecular and cytological alterations induced in a mammal (Mus musculus) fed ad libitum with a balanced pellet diet irradiated with 50 KGy gamma radiation from weaning, for different periods, are analyzed. The transient chromosomal changes that recall tumor-like phenomena could be the expression of the damage and repair processes induced by changed molecules present in irradiated food. The reversible alterations of DNA structure and cytoplasmatic soluble proteins observed in mice fed with irradiated pellet diet could be interpreted as a result of the enhancement of the repair processes which could also explain the significant increase of the radioresistance of DNA found at 200 days after irradiated food ingestion. Finally, our results would suggest an induction of a pseudo-neoplasia due to a prolongated and exclusive ingestion of food irradiated with sterilizing gamma dose. Moreover, the maintenance of the irradiated diet induce the reversion of the observed phenomena by an eventual activation of the repair mechanisms. (Author)

344

Wavelet analysis of molecular dynamics: Efficient extraction of time-frequency information in ultrafast optical processes  

Energy Technology Data Exchange (ETDEWEB)

New experimental techniques based on nonlinear ultrafast spectroscopies have been developed over the last few years, and have been demonstrated to provide powerful probes of quantum dynamics in different types of molecular aggregates, including both natural and artificial light harvesting complexes. Fourier transform-based spectroscopies have been particularly successful, yet “complete” spectral information normally necessitates the loss of all information on the temporal sequence of events in a signal. This information though is particularly important in transient or multi-stage processes, in which the spectral decomposition of the data evolves in time. By going through several examples of ultrafast quantum dynamics, we demonstrate that the use of wavelets provide an efficient and accurate way to simultaneously acquire both temporal and frequency information about a signal, and argue that this greatly aids the elucidation and interpretation of physical process responsible for non-stationary spectroscopic features, such as those encountered in coherent excitonic energy transport.

Prior, Javier; Castro, Enrique [Departamento de Física Aplicada, Universidad Politécnica de Cartagena, Cartagena 30202 (Spain); Chin, Alex W. [Theory of Condensed Matter Group, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Almeida, Javier; Huelga, Susana F.; Plenio, Martin B. [Institut für Theoretische Physik, Albert-Einstein-Allee 11, Universität Ulm, D-89069 Ulm (Germany)

2013-12-14

345

Wavelet analysis of molecular dynamics: Efficient extraction of time-frequency information in ultrafast optical processes  

International Nuclear Information System (INIS)

New experimental techniques based on nonlinear ultrafast spectroscopies have been developed over the last few years, and have been demonstrated to provide powerful probes of quantum dynamics in different types of molecular aggregates, including both natural and artificial light harvesting complexes. Fourier transform-based spectroscopies have been particularly successful, yet “complete” spectral information normally necessitates the loss of all information on the temporal sequence of events in a signal. This information though is particularly important in transient or multi-stage processes, in which the spectral decomposition of the data evolves in time. By going through several examples of ultrafast quantum dynamics, we demonstrate that the use of wavelets provide an efficient and accurate way to simultaneously acquire both temporal and frequency information about a signal, and argue that this greatly aids the elucidation and interpretation of physical process responsible for non-stationary spectroscopic features, such as those encountered in coherent excitonic energy transport

346

Selected materials of the international workshop on radiation risk and its origin at molecular and cellular level  

International Nuclear Information System (INIS)

The workshop ''International Workshop on Radiation Risk and its Origin at Molecular and Cellular Level'' was held at The Tokai Research Establishment, Japan Atomic Energy Research Institute, on the 6th and 7th of February 2003. The Laboratory of Radiation Risk Analysis of JAERI organized it. This international workshop attracted scientists from several different scientific areas, including radiation physics, radiation biology, molecular biology, crystallography of biomolecules, modeling and bio-informatics. Several foreign and domestic keynote speakers addresses the very fundamental areas of radiation risk and tried to establish a link between the fundamental studies at the molecular and cellular level and radiation damages at the organism. The symposium consisted of 13 oral lectures, 10 poster presentations and panel discussion. The 108 participants attended the workshop. This publication comprises of proceedings of oral and poster presentations where available. For the rest of contributions the abstracts or/and selections of presentation materials are shown instead. The 5 papers are indexed individually. (J.P.N.)

347

High-level waste processing at the Savannah River Site: An update  

International Nuclear Information System (INIS)

The Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS) in Aiken, SC mg began immobilizing high-level radioactive waste in borosilicate glass in 1996. Currently, the radioactive glass is being produced as a ''sludge-only'' composition by combining washed high-level waste sludge with glass frit. The glass is poured in stainless steel canisters which will eventually be disposed of in a permanent, geological repository. To date, DWPF has produced about 100 canisters of vitrified waste. Future processing operations will, be based on a ''coupled'' feed of washed high-level waste sludge, precipitated cesium, and glass frit. This paper provides an update of the processing activities completed to date, operational/flowsheet problems encountered, and programs underway to increase production rates

348

Optimization of preservation and processing of sea anemones for microbial community analysis using molecular tools.  

Science.gov (United States)

For several years, knowledge on the microbiome associated with marine invertebrates was impaired by the challenges associated with the characterization of bacterial communities. With the advent of culture independent molecular tools it is possible to gain new insights on the diversity and richness of microorganisms associated with marine invertebrates. In the present study, we evaluated if different preservation and processing methodologies (prior to DNA extraction) can affect the bacterial diversity retrieved from snakelocks anemone Anemonia viridis. Denaturing gradient gel electrophoresis (DGGE) community fingerprints were used as proxy to determine the bacterial diversity retrieved (H'). Statistical analyses indicated that preservation significantly affects H'. The best approach to preserve and process A. viridis biomass for bacterial community fingerprint analysis was flash freezing in liquid nitrogen (preservation) followed by the use of a mechanical homogenizer (process), as it consistently yielded higher H'. Alternatively, biomass samples can be processed fresh followed by cell lyses using a mechanical homogenizer or mortar &pestle. The suitability of employing these two alternative procedures was further reinforced by the quantification of the 16S rRNA gene; no significant differences were recorded when comparing these two approaches and the use of liquid nitrogen followed by processing with a mechanical homogenizer. PMID:25384534

Rocha, Joana; Coelho, Francisco J R C; Peixe, Luísa; Gomes, Newton C M; Calado, Ricardo

2014-01-01

349

Molecular dynamics simulation of the melting process in Ag27Cu13 core–shell nanoalloy  

International Nuclear Information System (INIS)

Highlights: • Melting process of Ag27Cu13 nanoalloy is studied by molecular dynamics simulation. • Different criteria are used to analyze thermal behavior of nanoalloy. • Steepest descent quenching method coupled to the isothermal MD simulations. • Multiple histogram method is used to remove the non-ergodicity problem. - Abstract: Molecular dynamics simulation in NVT ensemble coupled to steepest descent quenching method for studying melting mechanism of Ag27Cu13 nanoalloy, using thermodynamical, geometrical and dynamical criteria. Heat capacity values showed a strong fluctuation at temperatures of the phase coexistence region due to non-ergodicity in the simulation. Hence, in order to remove the non-ergodicity problem, multiple histogram method has been used. Heat capacity curve shows a shoulder peak at 620 K due to pre-melting of the surface atoms. Furthermore, at T = 840 K the melting behavior intensity of the atoms reaches to its maximum value, indicating that the melting process is completed. Considering the melting of 620 K for the nanoalloy, Lindemann parameter showed solid–solid isomerization at T = 480 K. Calculating ?shell and ?core proved that the corresponding solid–solid isomerization is only due to the shell atoms rearrangement. This fact is verified by quenching the configuration of the atoms by using steepest descent quenching method as well

350

Ultrasmall volume molecular isothermal amplification in microfluidic chip with advanced surface processing  

Energy Technology Data Exchange (ETDEWEB)

In this paper, we developed a metal micro-fluidic chip with advanced surface processing for ultra-small volume molecular isothermal amplification. This method takes advantages of the nucleic acid amplification with good stability and consistency, high sensitivity about 31 genomic DNA copies and bacteria specific gene identification. Based on the advanced surface processing, the bioreaction assays of nucleic acid amplification was dropped about 392nl in volume. A high numerical aperture confocal optical detection system was advanced to sensitively monitor the DNA amplification with low noise and high power collecting fluorescence near to the optical diffraction limit. A speedy nucleic acid isothermal amplification was performed in the ultra-small volume microfluidic chip, where the time at the inflexions of second derivative to DNA exponential amplified curves was brought forward and the sensitivity was improved about 65 folds to that of in current 25{mu}l Ep-tube amplified reaction, which indicates a promising clinic molecular diagnostics in the droplet amplification.

Huang Guoliang; Yang Xiaoyong [Department of Biomedical Engineering, the School of Medicine, Tsinghua University, Beijing, 100084 (China); Ma Li; Yang Xu, E-mail: tshgl@tsinghua.edu.cn [National Engineering Research Center for Beijing Biochip Technology, Beijing, 102206 (China)

2011-01-01

351

Recognition processes at a functionalized lipid surface observed with molecular resolution  

DEFF Research Database (Denmark)

The specific binding of proteins to functionalized lipid monolayers on aqueous subphases was characterized by neutron reflectivity and fluorescence microscopy measurements. Due to the high affinity and high specificity of their noncovalent interaction, streptavidin (SA) and biotin (vitamin H) were chosen as a model system to investigate the structural characteristics of a recognition process on a molecular length scale. Changes in the neutron reflection from the surfaces of NaCl aqueous (H2O or D2O) protein solutions (10(-8) M SA) were used to monitor the interaction of the protein with a monolayer of a biotinylated lipid in situ. Refinement of the reflectivity data and independent fluorescence microscopic observation of the interface using FITC-labeled SA showed that the protein forms macroscopically homogeneous (and presumably crystalline) domains covering a large portion of the surface. Moreover, the neutron reflection experiments clearly showed the formation of a monomolecular protein layer with an effective thickness, d(p) = 43.7 +/- 2 angstrom. The area per protein molecule occupied in the film was A0 = 2860 +/- 200 angstrom 2 and n(w) = 260 +/- 100 water molecules were associated with each protein molecule. Quantitative binding was found to occur at biotin surface concentrations as low as 1 molecule/1,250 angstrom 2 (compared with approximately 1 molecule/40 angstrom 2 for dense packing). This study demonstrates the application of a promising new tool for the systematic investigation of molecular recognition processes in protein/lipid model systems.

Vaknin, D.; Als-Nielsen, J.

1991-01-01

352

GLYCOSIDASES IN HUMAN BLOOD PLASMA AND URINE. MOLECULAR FORMS AND ACTIVITY LEVELS  

OpenAIRE

The isoe lect r i c f ocusing p a t terns and pH activity cur ves of f i ve glycosidas e e nzymes i n blood plasma and ur i ne were s t ud i e d . This s tudy demons trated the presence o f a sing le molecular f onn in a -glucosidase and of two mole cul a r fonns of the enzymes H-a ce t yl-B-D-gluco sarni nidase, Na c e t y l -•p-D-g a l a c t o s amin i ua s e and S-glucuronidase i n both plasma and urine . B-Galactosidase existed as a s i ng le major molecular f orm i n p l asma an...

Reza Seyed Yazdani

1982-01-01

353

Molecular Biology at the Quantum Level: Can Modern Density Functional Theory Forge the Path?  

OpenAIRE

Recent years have seen vast improvements in the ability of rigorous quantum-mechanical methods to treat systems of interest to molecular biology. In this review article, we survey common computational methods used to study such large, weakly bound systems, starting from classical simulations and reaching to quantum chemistry and density functional theory. We sketch their underlying frameworks and investigate their strengths and weaknesses when applied to potentially large bi...

Kolb, Brian; Thonhauser, T.

2012-01-01

354

Review process of PSA level 2 of KBR - Concept and Experience  

International Nuclear Information System (INIS)

In Germany, a periodic safety review (PSR) has to be performed every ten years by the utility. In the past, a PSR only included a plant-specific probabilistic safety analysis (PSA) Level 1 study. Since a revised version of the German PSA guideline has been released in 2005, these plant-specific PSAs have to include a PSA Level 2, too. For the NPP Brokdorf (KBR) PSA Level 2 project, an agreement was reached between all parties involved that the study will be performed not as a part of the PSR process, but supplementary to it. This paper will focus on conclusions and findings from an ongoing parallel review process of the first full scope PSA Level 2 performed by the utility for KBR, a typical German PWR-1300. The responsible authority 'Ministerium fuer Soziales, Gesundheit, Familie, Jugend und Senioren des Landes Schleswig- Holstein' (MSGF) initiated this parallel review process in agreement with the utility KBR and the E.ON Kernkraft in 2006. The project will be completed soon. Such a review process allows that essential steps of the PSA will be reviewed and commented before the PSA Level 2 will be finished. So the benefit from this parallel review process is a significant enhancement of the quality and completeness of the PSA Level 2 study as the majority of the recommendations given by the review team has been taken over by the utility and the developer of the PSA, the AREVA NP company. Further, a common understanding and agreement will be reached at the end betweenreement will be reached at the end between all parties involved on the major topics of the PSA Level 2 study. The paper is followed by the slides of the presentation. (authors)

355

On the use of a O 2:SF 6 plasma treatment on GaAs processed surfaces for molecular beam epitaxial regrowth  

Science.gov (United States)

Preparation of processed GaAs surface cleaning in view of molecular beam epitaxy regrowth by means of a O 2SF 6 microwave plasma has been investigated. Photoemission, Auger electron spectroscopy, atomic force microscopy and secondary ion mass spectrometry have been used for characterization. The O 2SF 6 plasma treatment was found to be very efficient for decontaminating the GaAs surface and leads to the formation of an oxide layer that can be taken off by a thermal or low-temperature H-plasma-assisted deoxidation. The levels of oxygen and carbon contaminants at the regrowth interface were measured to be in the range of a standard homoepitaxial layer-epiready substrate interface. Fluorine was observed to be eliminated upon deoxidation while sulphur is present, particularly in the case of low temperature grown layers. This plasma treatment was found to be efficient for preparation of processed GaAs surfaces for molecular beam epitaxial regrowth.

Desplats, O.; Gallo, P.; Doucet, J. B.; Monier, G.; Bideux, L.; Jalabert, L.; Arnoult, A.; Lacoste, G.; Armand, C.; Voillot, F.; Fontaine, C.

2009-01-01

356

On the use of a O2:SF6 plasma treatment on GaAs processed surfaces for molecular beam epitaxial regrowth  

International Nuclear Information System (INIS)

Preparation of processed GaAs surface cleaning in view of molecular beam epitaxy regrowth by means of a O2SF6 microwave plasma has been investigated. Photoemission, Auger electron spectroscopy, atomic force microscopy and secondary ion mass spectrometry have been used for characterization. The O2SF6 plasma treatment was found to be very efficient for decontaminating the GaAs surface and leads to the formation of an oxide layer that can be taken off by a thermal or low-temperature H-plasma-assisted deoxidation. The levels of oxygen and carbon contaminants at the regrowth interface were measured to be in the range of a standard homoepitaxial layer-epiready substrate interface. Fluorine was observed to be eliminated upon deoxidation while sulphur is present, particularly in the case of low temperature grown layers. This plasma treatment was found to be efficient for preparation of processed GaAs surfaces for molecular beam epitaxial regrowth.

357

GLYCOSIDASES IN HUMAN BLOOD PLASMA AND URINE. MOLECULAR FORMS AND ACTIVITY LEVELS  

Directory of Open Access Journals (Sweden)

Full Text Available The isoe lect r i c f ocusing p a t terns and pH activity cur ves of f i ve glycosidas e e nzymes i n blood plasma and ur i ne were s t ud i e d . This s tudy demons trated the presence o f a sing le molecular f onn in a -glucosidase and of two mole cul a r fonns of the enzymes H-a ce t yl-B-D-gluco sarni nidase, Na c e t y l -•p-D-g a l a c t o s amin i ua s e and S-glucuronidase i n both plasma and urine . B-Galactosidase existed as a s i ng le major molecular f orm i n p l asma and a t l e a st t wo molecular forms in urine. Spe cific activity of each~ le n zyme was determined in p lasma and urine The validity o f taking the ratio between two e n zvrne activities as an index for scr een .l.ng of fr ene t ic di s e a s e is discussed.

Reza Seyed Yazdani

1982-05-01

358

Global plant-responding mechanisms to salt stress: physiological and molecular levels and implications in biotechnology.  

Science.gov (United States)

Abstract The increasing seriousness of salinization aggravates the food, population and environmental issues. Ameliorating the salt-resistance of plants especially the crops is the most effective measure to solve the worldwide problem. The salinity can cause damage to plants mainly from two aspects: hyperosmotic and hyperionic stresses leading to the restrain of growth and photosynthesis. To the adverse effects, the plants derive corresponding strategies including: ion regulation and compartmentalization, biosynthesis of compatible solutes, induction of antioxidant enzymes and plant hormones. With the development of molecular biology, our understanding of the molecular and physiology knowledge is becoming clearness. The complex signal transduction underlying the salt resistance is being illuminated brighter and clearer. The SOS pathway is the central of the cell signaling in salt stress. The accumulation of the compatible solutes and the activation of the antioxidant system are the effective measures for plants to enhance the salt resistance. How to make full use of our understanding to improve the output of crops is a huge challenge for us, yet the application of the genetic engineering makes this possible. In this review, we will discuss the influence of the salt stress and the response of the plants in detail expecting to provide a particular account for the plant resistance in molecular, physiological and transgenic fields. PMID:24738851

Tang, Xiaoli; Mu, Xingmin; Shao, Hongbo; Wang, Hongyan; Brestic, Marian

2014-04-16

359

Transcriptional profiling at whole population and single cell levels reveals somatosensory neuron molecular diversity.  

Science.gov (United States)

The somatosensory nervous system is critical for the organism's ability to respond to mechanical, thermal, and nociceptive stimuli. Somatosensory neurons are functionally and anatomically diverse but their molecular profiles are not well-defined. Here, we used transcriptional profiling to analyze the detailed molecular signatures of dorsal root ganglion (DRG) sensory neurons. We used two mouse reporter lines and surface IB4 labeling to purify three major non-overlapping classes of neurons: 1) IB4(+)SNS-Cre/TdTomato(+), 2) IB4(-)SNS-Cre/TdTomato(+), and 3) Parv-Cre/TdTomato(+) cells, encompassing the majority of nociceptive, pruriceptive, and proprioceptive neurons. These neurons displayed distinct expression patterns of ion channels, transcription factors, and GPCRs. Highly parallel qRT-PCR analysis of 334 single neurons selected by membership of the three populations demonstrated further diversity, with unbiased clustering analysis identifying six distinct subgroups. These data significantly increase our knowledge of the molecular identities of known DRG populations and uncover potentially novel subsets, revealing the complexity and diversity of those neurons underlying somatosensation. PMID:25525749

Chiu, Isaac M; Barrett, Lee B; Williams, Erika K; Strochlic, David E; Lee, Seungkyu; Weyer, Andy D; Lou, Shan; Bryman, Gregory S; Roberson, David P; Ghasemlou, Nader; Piccoli, Cara; Ahat, Ezgi; Wang, Victor; Cobos, Enrique J; Stucky, Cheryl L; Ma, Qiufu; Liberles, Stephen D; Woolf, Clifford J

2015-01-01

360

Regulating risk or risking regulation? Construal levels and depletion effects in the processing of health messages  

OpenAIRE

The depletion effect occurs when individuals who exert self-control in a previous task (i.e., depleted individuals) exhibit less self-control on a subsequent task relative to individuals who did not previously exert self-control. This article presents two experiments that implicate construal levels to understand the processes underlying depletion effects in the context of consumer health. At low-level construals, individuals rely on resource accessibility cues (e.g., feelings of tiredness) to...

Wan, Ew; Agrawal, N.

2009-01-01

361

Improving Streaming Video Segmentation with Early and Mid-Level Visual Processing  

OpenAIRE

Despite recent advances in video segmentation, many opportunities remain to improve it using a variety of low and mid-level visual cues. We propose improvements to the leading streaming graph-based hierarchical video segmentation (streamGBH) method based on early and mid level visual processing. The extensive experimental analysis of our approach validates the improvement of hierarchical supervoxel representation by incorporating motion and color with effective filtering. We...

Tripathi, Subarna; Hwang, Youngbae; Belongie, Serge; Nguyen, Truong

2014-01-01

362

The influence of deck storage and initial processing on patulin levels in apple juice.  

Science.gov (United States)

Patulin, a secondary metabolite produced by Penicillium expansum and some other fungal species, is a common contaminant of ripened apples used for the production of apple juice concentrates. The limited availability of suitable storage facilities may result in fruit being subjected to storage in the open ('deck storage') for extended periods of time, prior to processing. A study was conducted to determine the influence that deck storage and subsequent initial processing practices had on patulin levels in freshly pressed juice. Over the study period, triplicate samples were collected at four strategic processing points from individual consignments of Granny Smith apples deck-stored for 7, 15 and 33 days, respectively. Over the study period, mean patulin levels in non-processed fruit increased from 90 to 2445 ng/g, respectively, but decreased to between 75 and 695 ng/g, respectively, following a water wash step. Subsequent removal of rotten/damaged fruit decreased patulin levels further (to between 55 and 405 ng/g, respectively), although the numerical decreases between sampling points were not shown to be statistically significant (P > 0.05). However, patulin levels were significantly higher (P < 0.05) in the rejected rotten/damaged fruit (mean levels ranged from 1120 to 6235 ng/g, respectively). P. expansum was the major patulin-producing fungus isolated from the juice samples. The mycological analyses tended to support the chemical data, in that removal of the rotten/damaged fractions significantly reduced total fungal counts in the juice samples. PMID:9328526

Sydenham, E W; Vismer, H F; Marasas, W F; Brown, N L; Schlechter, M; Rheeder, J P

1997-07-01

363

False memory and level of processing effect: an event-related potential study.  

Science.gov (United States)

Event-related potentials (ERPs) were used to determine the effects of level of processing on true and false memory, using the Deese-Roediger-McDermott (DRM) paradigm. In the DRM paradigm, lists of words highly associated to a single nonpresented word (the 'critical lure') are studied and, in a subsequent memory test, critical lures are often falsely remembered. Lists with three critical lures per list were auditorily presented here to participants who studied them with either a shallow (saying whether the word contained the letter 'o') or a deep (creating a mental image of the word) processing task. Visual presentation modality was used on a final recognition test. True recognition of studied words was significantly higher after deep encoding, whereas false recognition of nonpresented critical lures was similar in both experimental groups. At the ERP level, true and false recognition showed similar patterns: no FN400 effect was found, whereas comparable left parietal and late right frontal old/new effects were found for true and false recognition in both experimental conditions. Items studied under shallow encoding conditions elicited more positive ERP than items studied under deep encoding conditions at a 1000-1500 ms interval. These ERP results suggest that true and false recognition share some common underlying processes. Differential effects of level of processing on true and false memory were found only at the behavioral level but not at the ERP level. PMID:22811058

Beato, Maria Soledad; Boldini, Angela; Cadavid, Sara

2012-09-12

364

Deciphering Membrane-Associated Molecular Processes in Target Tissue of Autoimmune Uveitis by Label-Free Quantitative Mass Spectrometry*  

Science.gov (United States)

Autoimmune uveitis is a blinding disease presenting with autoantibodies against eye-specific proteins as well as autoagressive T cells invading and attacking the immune-privileged target tissue retina. The molecular events enabling T cells to invade and attack the tissue have remained elusive. Changes in membrane protein expression patterns between diseased and healthy stages are especially interesting because initiating events of disease will most likely occur at membranes. Since disease progression is accompanied with a break-down of the blood-retinal barrier, serum-derived proteins mask the potential target tissue-related changes. To overcome this limitation, we used membrane-enriched fractions derived from retinas of the only available spontaneous animal model for the disease equine recurrent uveitis, and compared expression levels by a label-free LC-MSMS-based strategy to healthy control samples. We could readily identify a total of 893 equine proteins with 57% attributed to the Gene Ontology project term “membrane.” Of these, 179 proteins were found differentially expressed in equine recurrent uveitis tissue. Pathway enrichment analyses indicated an increase in proteins related to antigen processing and presentation, TNF receptor signaling, integrin cell surface interactions and focal adhesions. Additionally, loss of retina-specific proteins reflecting decrease of vision was observed as well as an increase in Müller glial cell-specific proteins indicating glial reactivity. Selected protein candidates (caveolin 1, integrin alpha 1 and focal adhesion kinase) were validated by immunohistochemistry and tissue staining pattern pointed to a significant increase of these proteins at the level of the outer limiting membrane which is part of the outer blood-retinal barrier. Taken together, the membrane enrichment in combination with LC-MSMS–based label-free quantification greatly increased the sensitivity of the comparative tissue profiling and resulted in detection of novel molecular pathways related to equine recurrent uveitis. PMID:20601722

Hauck, Stefanie M.; Dietter, Johannes; Kramer, Roxane L.; Hofmaier, Florian; Zipplies, Johanna K.; Amann, Barbara; Feuchtinger, Annette; Deeg, Cornelia A.; Ueffing, Marius

2010-01-01

365

Deciphering membrane-associated molecular processes in target tissue of autoimmune uveitis by label-free quantitative mass spectrometry.  

Science.gov (United States)

Autoimmune uveitis is a blinding disease presenting with autoantibodies against eye-specific proteins as well as autoagressive T cells invading and attacking the immune-privileged target tissue retina. The molecular events enabling T cells to invade and attack the tissue have remained elusive. Changes in membrane protein expression patterns between diseased and healthy stages are especially interesting because initiating events of disease will most likely occur at membranes. Since disease progression is accompanied with a break-down of the blood-retinal barrier, serum-derived proteins mask the potential target tissue-related changes. To overcome this limitation, we used membrane-enriched fractions derived from retinas of the only available spontaneous animal model for the disease equine recurrent uveitis, and compared expression levels by a label-free LC-MSMS-based strategy to healthy control samples. We could readily identify a total of 893 equine proteins with 57% attributed to the Gene Ontology project term "membrane." Of these, 179 proteins were found differentially expressed in equine recurrent uveitis tissue. Pathway enrichment analyses indicated an increase in proteins related to antigen processing and presentation, TNF receptor signaling, integrin cell surface interactions and focal adhesions. Additionally, loss of retina-specific proteins reflecting decrease of vision was observed as well as an increase in Müller glial cell-specific proteins indicating glial reactivity. Selected protein candidates (caveolin 1, integrin alpha 1 and focal adhesion kinase) were validated by immunohistochemistry and tissue staining pattern pointed to a significant increase of these proteins at the level of the outer limiting membrane which is part of the outer blood-retinal barrier. Taken together, the membrane enrichment in combination with LC-MSMS-based label-free quantification greatly increased the sensitivity of the comparative tissue profiling and resulted in detection of novel molecular pathways related to equine recurrent uveitis. PMID:20601722

Hauck, Stefanie M; Dietter, Johannes; Kramer, Roxane L; Hofmaier, Florian; Zipplies, Johanna K; Amann, Barbara; Feuchtinger, Annette; Deeg, Cornelia A; Ueffing, Marius

2010-10-01

366

Evaluation of high-level waste pretreatment processes with an approximate reasoning model  

International Nuclear Information System (INIS)

The development of an approximate-reasoning (AR)-based model to analyze pretreatment options for high-level waste is presented. AR methods are used to emulate the processes used by experts in arriving at a judgment. In this paper, the authors first consider two specific issues in applying AR to the analysis of pretreatment options. They examine how to combine quantitative and qualitative evidence to infer the acceptability of a process result using the example of cesium content in low-level waste. They then demonstrate the use of simple physical models to structure expert elicitation and to produce inferences consistent with a problem involving waste particle size effects

367

Planning and organization of the learning process in art education at primary level  

OpenAIRE

Planning and organization in any learning process is difficult. It consists of accepted curriculum, organization of the school and local community. In what extent and how the teachers will implement formal directions into the classroom planning, depends on the teacher as the individual and his planning of the pedagogical process. (Uljens, 1997) Theoretical part of the thesis will present education at primary level in the Republic of Slovenia. It will present the documents in primary school...

Jakopin, Nives

2011-01-01

368

Combined Word-Length Allocation and High-Level Synthesis of Digital Signal Processing Circuits  

OpenAIRE

This work is focused on the synthesis of Digital Signal Processing (DSP) circuits usingc specific hardware architectures. Due to its complexity, the design process has been subdivided into separate tasks, thus hindering the global optimization of the resulting systems. The author proposes the study of the combination of two major design tasks, Word-Length Allocation (WLA) and High-Level Synthesis (HLS), aiming at the optimization of DSP implementations using modern Field Programmable Gate...

Caffarena Ferna?ndez, Gabriel

2008-01-01

369

Environmental Assessment Idaho National Engineering Laboratory, low-level and mixed waste processing  

Energy Technology Data Exchange (ETDEWEB)

The Department of Energy (DOE) has prepared an environmental assessment (EA), DOE/EA-0843, for the Idaho National Engineering Laboratory (INEL) low-level and mixed waste processing. The original proposed action, as reviewed in this EA, was (1) to incinerate INEL`s mixed low-level waste (MLLW) at the Waste Experimental Reduction Facility (WERF); (2) reduce the volume of INEL generated low-level waste (LLW) through sizing, compaction, and stabilization at the WERF; and (3) to ship INEL LLW to a commercial incinerator for supplemental LLW volume reduction.

1994-06-01

370

Ceramic process and plant design for high-level nuclear waste immobilization  

International Nuclear Information System (INIS)

In the last 3 years, significant advances in ceramic technology for high-level nuclear waste solidification have been made. Product quality in terms of leach-resistance, compositional uniformity, structural integrity, and thermal stability promises to be superior to borosilicate glass. This paper addresses the process effectiveness and preliminary designs for glass and ceramic immobilization plants. The reference two-step ceramic process utilizes fluid-bed calcination (FBC) and hot isostatic press (HIP) consolidation. Full-scale demonstration of these well-developed processing steps has been established at DOE and/or commercial facilities for processing radioactive materials. Based on Savannah River-type waste, our model predicts that the capital and operating cost for the solidification of high-level nuclear waste is about the same for the ceramic and glass options. However, when repository costs are included, the ceramic option potentially offers significantly better economics due to its high waste loading and volume reduction. Volume reduction impacts several figures of merit in addition to cost such as system logistics, storage, transportation, and risk. The study concludes that the ceramic product/process has many potential advantages, and rapid deployment of the technology could be realized due to full-scale demonstrations of FBC and HIP technology in radioactive environments. Based on our finding and those of others, the ceramic innovation not only offers a viable backup to the glass reference process but promises to be a viable future option for new high-level nuclear waste management opportunities

371

Observation of unexpected energy levels in molecular hydrogen and ortho-para energy transfer  

Energy Technology Data Exchange (ETDEWEB)

We report the observation of eight unexpected energy levels close to but clearly different from H{sub 2} {ital B} {sup 1}{Sigma}{sub {ital u}}{sup +} levels. In transitions involving these levels vacuum-ultraviolet transitions terminating in p-H{sub 2} levels are observed subsequent to two-photon {ital Q}(1) excitation {ital X}{sup 1}{Sigma}{sub {ital g}}{sup +}({ital v}{prime}{prime}=0){r arrow}{ital EF} {sup 1}{Sigma}{sub {ital g}}{sup +}({ital v}{prime}=6) of o-H{sub 2}. Several findings indicate that these strange levels may be a manifestation of electronically excited H{sub 4}, which has been discussed in a number of theoretical contributions.

Czarnetzki, U.; Doebele, H.F. (Institut fuer Laser- und Plasmaphysik, Universitaet Gesamthochschule Essen, D-4300 Essen 1, Federal Republic of Germany (DE))

1990-06-04

372

Management of high level radioactive aqueous effluents in advanced partitioning processes  

International Nuclear Information System (INIS)

The context of this study is the development of management strategies for the high level radioactive aqueous effluents generated by advanced minor actinides partitioning processes. In the present nuclear reprocessing plants, high level liquid wastes are concentrated via successive evaporations, with or without de-nitration, to reach the inlet specifications of the downstream processing steps. In contrast to the PUREX process, effluents from advanced actinides partitioning processes contain large amounts of organic compounds (complexing agents, buffers or reducing reagents), which could disrupt concentration operations. Thus, in parallel with new partitioning process development, the compatibility of usual concentration operations with the high level liquid waste issued from them are investigated, and, if necessary, additional treatments to eliminate remaining organic compounds are reviewed. The behaviour of each reagent and related identified by-products is studied in laboratory-scale devices representative of industrial operating conditions. Final concentrated solutions (actinide or fission solutions) and the resulting distillates (i.e. decontaminated effluents) are checked in terms of compatibility with the downstream specifications. Process implementation and safety aspects are also evaluated. Kinetic and thermodynamic constants are measured. After the collection of these data, the effectiveness of the overall continuous process of the effluent treatment (combinatiocess of the effluent treatment (combination of elementary operations) is evaluated through semi-empirical models which are also able to optimize the conditions for implementation. First results indicate that nitric acid streams containing complexing agents (oxalic acid, HEDTA, DTPA) will be managed by usual concentration processes, while buffered solutions ( containing glycolic, citric or malonic acid) will require additional treatments to lower organic carbon concentration. Oxidation process by hydrogen peroxide at boiling temperature has been shown to be very efficient as additional treatment in most cases. (authors)

373

Management of high level radioactive aqueous effluents in advanced partitioning processes  

Energy Technology Data Exchange (ETDEWEB)

The context of this study is the development of management strategies for the high level radioactive aqueous effluents generated by advanced minor actinides partitioning processes. In the present nuclear reprocessing plants, high level liquid wastes are concentrated via successive evaporations, with or without de-nitration, to reach the inlet specifications of the downstream processing steps. In contrast to the PUREX process, effluents from advanced actinides partitioning processes contain large amounts of organic compounds (complexing agents, buffers or reducing reagents), which could disrupt concentration operations. Thus, in parallel with new partitioning process development, the compatibility of usual concentration operations with the high level liquid waste issued from them are investigated, and, if necessary, additional treatments to eliminate remaining organic compounds are reviewed. The behaviour of each reagent and related identified by-products is studied in laboratory-scale devices representative of industrial operating conditions. Final concentrated solutions (actinide or fission solutions) and the resulting distillates (i.e. decontaminated effluents) are checked in terms of compatibility with the downstream specifications. Process implementation and safety aspects are also evaluated. Kinetic and thermodynamic constants are measured. After the collection of these data, the effectiveness of the overall continuous process of the effluent treatment (combination of elementary operations) is evaluated through semi-empirical models which are also able to optimize the conditions for implementation. First results indicate that nitric acid streams containing complexing agents (oxalic acid, HEDTA, DTPA) will be managed by usual concentration processes, while buffered solutions ( containing glycolic, citric or malonic acid) will require additional treatments to lower organic carbon concentration. Oxidation process by hydrogen peroxide at boiling temperature has been shown to be very efficient as additional treatment in most cases. (authors)

Pochon, Patrick; Sans, Daniele; Lartigaud, Cathy; Bisel, Isabelle [Commissariat a l' Energie Atomique, Centre de Marcoule, BP 17171, Bagnols sur Ceze, 30207 (France)

2009-06-15

374

The early molecular processes underlying the neurological manifestations of an animal model of Wilson's disease.  

Science.gov (United States)

The Long-Evans Cinnamon (LEC) rat shows age-dependent hepatic manifestations that are similar to those of Wilson's disease (WD). The pathogenic process in the brain has, however, not been evaluated in detail due to the rarity of the neurological symptoms. However, copper accumulation is noted in LEC rat brain tissue from 24 weeks of age, which results in oxidative injuries. The current study investigated the gene expression profiles of LEC rat brains at 24 weeks of age in order to identify the important early molecular changes that underlie the development of neurological symptoms in WD. Biological ontology-based analysis revealed diverse altered expressions of the genes related to copper accumulation. Of particular interest, we found altered expression of genes connected to mitochondrial respiration (Sdhaf2 and Ndufb7), calcineurin-mediated cellular processes (Ppp3ca, Ppp3cb, and Camk2a), amyloid precursor protein (Anks1b and A2m) and alpha-synuclein (Snca). In addition to copper-related changes, compensatory upregulations of Cp and Hamp reflect iron-mediated neurotoxicity. Of note, reciprocal expression of Asmt and Bhmt is an important clue that altered S-adenosylhomocysteine metabolism underlies brain injury in WD, which is directly correlated to the decreased expression of S-adenosylhomocysteine hydrolase in hepatic tissue in LEC rats. In conclusion, our study indicates that diverse molecular changes, both variable and complex, underlie the development of neurological manifestations in WD. Copper-related injuries were found to be the principal pathogenic process, but Fe- or adenosylhomocysteine-related injuries were also implicated. Investigations using other animal models or accessible human samples will be required to confirm our observations. PMID:23519153

Lee, Beom Hee; Kim, Joo Hyun; Kim, Jae-Min; Heo, Sun Hee; Kang, Minji; Kim, Gu-Hwan; Choi, Jin-Ho; Yoo, Han-Wook

2013-05-01

375

Mechanical properties and biocompatibility of melt processed, self-reinforced ultrahigh molecular weight polyethylene.  

Science.gov (United States)

The low efficiency of fabrication of ultrahigh molecular weight polyethylene (UHMWPE)-based artificial knee joint implants is a bottleneck problem because of its extremely high melt viscosity. We prepared melt processable UHMWPE (MP-UHMWPE) by addition of 9.8 wt% ultralow molecular weight polyethylene (ULMWPE) as a flow accelerator. More importantly, an intense shear flow was applied during injection molding of MP-UHMWPE, which on one hand, promoted the self-diffusion of UHMWPE chains, thus effectively reducing the structural defects; on the other hand, increased the overall crystallinity and induced the formation of self-reinforcing superstructure, i.e., interlocked shish-kebabs and oriented lamellae. Aside from the good biocompatibility, and the superior fatigue and wear resistance to the compression-molded UHMWPE, the injection-molded MP-UHMWPE exhibits a noteworthy enhancement in tensile properties and impact strength, where the yield strength increases to 46.3 ± 4.4 MPa with an increment of 128.0%, the ultimate tensile strength and Young's modulus rise remarkably up to 65.5 ± 5.0 MPa and 1248.7 ± 45.3 MPa, respectively, and the impact strength reaches 90.6 kJ/m(2). These results suggested such melt processed and self-reinforced UHMWPE parts hold a great application promise for use of knee joint implants, particularly for younger and more active patients. Our work sets up a new method to fabricate high-performance UHMWPE implants by tailoring the superstructure during thermoplastic processing. PMID:24835044

Huang, Yan-Fei; Xu, Jia-Zhuang; Li, Jian-Shu; He, Ben-Xiang; Xu, Ling; Li, Zhong-Ming

2014-08-01

376

Continuum level treatment of electronic polarization in the framework of molecular simulations of solvation effects  

International Nuclear Information System (INIS)

The hybrid molecular-continuum model for polar solvation considered in this paper combines the dielectric continuum approximation for treating fast electronic (inertialess) polarization effects and a molecular dynamics (MD) simulation for the slow (inertial) polarization component, including orientational and translational solvent modes. The inertial polarization is generated by average charge distributions of solvent particles, composed of permanent and induced (electronic) components. MD simulations are performed in a manner consistent with the choice of solvent and solute charges such that all electrostatic interactions are scaled by the factor 1/??, where ?? is the optical dielectric permittivity. This approach yields an ensemble of equilibrium solvent configurations adjusted to the electric field created by a charged or strongly polar solute. The electrostatic solvent response field is found as the solution of the Poisson equation including both solute and explicit solvent charges, with accurate account of electrostatic boundary conditions at the surfaces separating spatial regions with different dielectric permittivities. Both equilibrium and nonequilibrium solvation effects can be studied by means of this model, and their inertial and inertialess contributions are naturally separated. The methodology for computation of charge transfer reorganization energies is developed and applied to a model two-site dipolar system in the SPC watersite dipolar system in the SPC water solvent. Three types of charge transfer reactions are considered. The standard linear-response approach yields high accuracy for each particular reaction, but proves to be significantly in error when reorganization energies of different reactions were compared. This result has a purely molecular origin and is absent within a conventional continuum solvent model

377

Molecular-level mechanisms of nanoparticle detachment in laser-induced plasma shock waves  

International Nuclear Information System (INIS)

Detachment and detachment mechanisms of nanoparticles from flat surfaces subjected to shock waves are investigated by employing molecular gas dynamic simulations using the direct simulation Monte Carlo method and experimental transient pressure data. Two mechanisms for nanoparticle detachment based on rolling moment resistance of the adhesion bond and the elastic restitution effect are introduced. As a result of present simulations, it is computationally demonstrated that the pulsed laser-induced shock waves can generate sufficient rolling moments to detach sub-100-nm particles and initiate removal. The transient moment exerted on a 60 nm polystyrene latex particle on a silicon substrate is presented and discussed

378

Atomic-level protein structure refinement using fragment guided molecular dynamics conformation sampling  

OpenAIRE

One of critical difficulties of molecular dynamics (MD) simulations in protein structure refinement is that the physics-based energy landscape lacks of middle-range funnel to guide non-native conformations towards near-native states. We propose to use the target model as probe to identify fragmental analogs from PDB. The distance maps are then used to re-shape the MD energy funnel. The protocol was tested on 181 benchmarking and 26 CASP targets. It was found that structure models of correct f...

Zhang, Jian; Liang, Yu; Zhang, Yang

2011-01-01

379

Fast two-phonon relaxation process between the Landau levels of graphene on different polar substrates  

Science.gov (United States)

Within the frame of Huang-Rhys's lattice relaxation model, we theoretically investigate the carrier relaxation mediated by two-phonon processes, which consists in polar surface optical phonon and longitudinal acoustic phonon emission between the Landau levels of graphene on different polar substrates. This two-phonon relaxation process is very fast within the picosecond scale and may seriously hinder the carrier multiplication based on effective Auger processes. Moreover, the polarizability of the polar substrate plays an important role in determining the relaxation time. These results could be helpful in designing graphene-based photoelectric and photodetector devices.

Wang, Zi-Wu; Liu, Lei; Li, Zhi-Qing

2014-11-01

380

High level model predictive control for plug-and-play process control with stability guaranty  

DEFF Research Database (Denmark)

In this paper a method for designing a stabilizing high level model predictive controller for a hierarchical plug- and-play process is presented. This is achieved by abstracting the lower layers of the controller structure as low order models with uncertainty and by using a robust model predictive controller for generating the references for these. A simulation example, in which the actuators in a process control system are changed, is reported to show the potential of this approach for plug and play process control.

Michelsen, Axel Gottlieb; Stoustrup, Jakob

2010-01-01

381

An innovative approach to solid Low Level Radioactive Waste processing and disposal  

International Nuclear Information System (INIS)

This paper will focus on a new system of Low Level Radioactive Waste (LLW) accumulation, processing and packaging, as-well as the implementation of a Laboratory-wide training program used to introduce new waste accumulation containers to all of the on-site radioactive waste generators, and to train them on the requirements of this innovative waste characterization and documentation program

382

Higher-level processes in the formation and application of associations during action understanding.  

Science.gov (United States)

The associative account described in the target article provides a viable explanation for the origin of mirror neurons. We argue here that if mirror neurons develop purely by associative learning, then they cannot by themselves explain intentional action understanding. Higher-level processes seem to be involved in the formation of associations as well as in their application during action understanding. PMID:24775159

Heil, Lieke; van Pelt, Stan; Kwisthout, Johan; van Rooij, Iris; Bekkering, Harold

2014-04-01

383

Towards understanding the molecular recognition process in prokaryotic zinc-finger domain.  

Science.gov (United States)

Eukaryotic Cys2His2 zinc finger domain is one of the most common and important structural motifs involved in protein-DNA interaction. The recognition motif is characterized by the tetrahedral coordination of a zinc ion by conserved cysteine and histidine residues. We have characterized the prokaryotic Cys2His2 zinc finger motif, included in the DNA binding region (Ros87) of Ros protein from Agrobacterium tumefaciens, demonstrating that, although possessing a similar zinc coordination sphere, this domain presents significant differences from its eukaryotic counterpart. Furthermore, basic residues flanking the zinc binding region on either side have been demonstrated, by Electrophoretic Mobility Shift Assay (EMSA) experiments, to be essential for Ros DNA binding. In spite of this wealth of knowledge, the structural details of the mechanism through which the prokaryotic zinc fingers recognize their target genes are still unclear. Here, to gain insights into the molecular DNA recognition process of prokaryotic zinc finger domains we applied a strategy in which we performed molecular docking studies using a combination of Nuclear Magnetic Resonance (NMR) and Molecular Dynamics (MD) simulations data. The results demonstrate that the MD ensemble provides a reasonable picture of Ros87 backbone dynamics in solution. The Ros87-DNA model indicates that the interaction involves the first two residue of the first ?-helix, and several residues located in the basic regions flanking the zinc finger domain. Interestingly, the prokaryotic zinc finger domain, mainly with the C-terminal tail that is wrapped around the DNA, binds a more extended recognition site than the eukaryotic counterpart. Our analysis demonstrates that the introduction of the protein flexibility in docking studies can improve, in terms of accuracy, the quality of the obtained models and could be particularly useful for protein showing high conformational heterogeneity as well as for computational drug design applications. PMID:25240418

Russo, Luigi; Palmieri, Maddalena; Caso, Jolanda Valentina; Abrosca, Gianluca D'; Diana, Donatella; Malgieri, Gaetano; Baglivo, Ilaria; Isernia, Carla; Pedone, Paolo V; Fattorusso, Roberto

2015-02-16

384

Molecular reordering processes on ice (0001) surfaces from long timescale simulations  

Science.gov (United States)

We report results of long timescale adaptive kinetic Monte Carlo simulations aimed at identifying possible molecular reordering processes on both proton-disordered and ordered (Fletcher) basal plane (0001) surfaces of hexagonal ice. The simulations are based on a force field for flexible molecules and span a time interval of up to 50 ?s at a temperature of 100 K, which represents a lower bound to the temperature range of earth's atmosphere. Additional calculations using both density functional theory and an ab initio based polarizable potential function are performed to test and refine the force field predictions. Several distinct processes are found to occur readily even at this low temperature, including concerted reorientation (flipping) of neighboring surface molecules, which changes the pattern of dangling H-atoms, and the formation of interstitial defects by the downwards motion of upper-bilayer molecules. On the proton-disordered surface, one major surface roughening process is observed that significantly disrupts the crystalline structure. Despite much longer simulation time, such roughening processes are not observed on the highly ordered Fletcher surface which is energetically more stable because of smaller repulsive interaction between neighboring dangling H-atoms. However, a more localized process takes place on the Fletcher surface involving a surface molecule transiently leaving its lattice site. The flipping process provides a facile pathway of increasing proton-order and stabilizing the surface, supporting a predominantly Fletcher-like ordering of low-temperature ice surfaces. Our simulations also show that eventual proton-disordered patches on the surface may induce significant local reconstructions. Further, a subset of the molecules on the Fletcher surface are susceptible to forming interstitial defects which might provide active sites for various chemical reactions in the atmosphere.

Pedersen, Andreas; Wikfeldt, Kjartan T.; Karssemeijer, Leendertjan; Cuppen, Herma; Jónsson, Hannes

2014-12-01

385

Molecular reordering processes on ice (0001) surfaces from long timescale simulations.  

Science.gov (United States)

We report results of long timescale adaptive kinetic Monte Carlo simulations aimed at identifying possible molecular reordering processes on both proton-disordered and ordered (Fletcher) basal plane (0001) surfaces of hexagonal ice. The simulations are based on a force field for flexible molecules and span a time interval of up to 50 ?s at a temperature of 100 K, which represents a lower bound to the temperature range of earth's atmosphere. Additional calculations using both density functional theory and an ab initio based polarizable potential function are performed to test and refine the force field predictions. Several distinct processes are found to occur readily even at this low temperature, including concerted reorientation (flipping) of neighboring surface molecules, which changes the pattern of dangling H-atoms, and the formation of interstitial defects by the downwards motion of upper-bilayer molecules. On the proton-disordered surface, one major surface roughening process is observed that significantly disrupts the crystalline structure. Despite much longer simulation time, such roughening processes are not observed on the highly ordered Fletcher surface which is energetically more stable because of smaller repulsive interaction between neighboring dangling H-atoms. However, a more localized process takes place on the Fletcher surface involving a surface molecule transiently leaving its lattice site. The flipping process provides a facile pathway of increasing proton-order and stabilizing the surface, supporting a predominantly Fletcher-like ordering of low-temperature ice surfaces. Our simulations also show that eventual proton-disordered patches on the surface may induce significant local reconstructions. Further, a subset of the molecules on the Fletcher surface are susceptible to forming interstitial defects which might provide active sites for various chemical reactions in the atmosphere. PMID:25527956

Pedersen, Andreas; Wikfeldt, Kjartan T; Karssemeijer, Leendertjan; Cuppen, Herma; Jónsson, Hannes

2014-12-21

386

Molecular-level understanding of the WGS and reverse WGS reactions on Rh through hierarchical multiscale approach  

OpenAIRE

Hierarchically combining semi-empirical methods and first-principles calculations we gain a novel and noteworthy picture of the molecular-level mechanisms that govern the water-gas-shift (WGS) and reverse water-gas-shift (r-WGS) reactions on Rh catalysts. Central to this picture is that the WGS and r-WGS follow two different dominant reaction mechanisms: WGS proceeds according to a carboxyl (COOH) mechanism, whereas r-WGS proceeds according to a redox (CO2 {\\to} CO + O) mech...

Maestri, Matteo; Reuter, Karsten

2012-01-01

387

Complete NLO QCD Corrections for Tree Level Delta F = 2 FCNC Processe  

CERN Document Server

Anticipating the important role of tree level FCNC processes in the indirect search for new physics at distance scales as short as 10^-19-10^-21 m, we present complete NLO QCD corrections to tree level Delta F=2 processes mediated by heavy colourless gauge bosons and scalars. Such contributions can be present at the fundamental level when GIM mechanism is absent as in numerous Z' models, gauged flavour models with new heavy neutral gauge bosons and Left-Right symmetric models with heavy neutral scalars. They can also be generated at one loop in models having GIM at the fundamental level and MFV of which Two-Higgs Doublet models with and without SUSY are the best known examples. In models containing vectorial heavy fermions that mix with the standard chiral quarks and models in which Z and SM neutral Higgs H mix with new heavy gauge bosons and scalars also tree-level Z and SM neutral Higgs contributions to Delta F=2 processes are possible. In all these extensions new local operators are generated having Wilson...

Buras, Andrzej J

2012-01-01

388

Molecular-level characterization of elastin-like constructs and human aortic elastin.  

Science.gov (United States)

This study aimed to characterize the structures of two elastin-like constructs, one composed of a cross-linked elastin-like polypeptide and the other one of cross-linked tropoelastin, and native aortic elastin. The structures of the insoluble materials and human aortic elastin were investigated using scanning electron microscopy. Additionally, all samples were digested with enzymes of different specificities, and the resultant peptide mixtures were characterized by ESI mass spectrometry and MALDI mass spectrometry. The MS(2) data was used to sequence linear peptides, and cross-linked species were analyzed with the recently developed software PolyLinX. This enabled the identification of two intramolecularly cross-linked peptides containing allysine aldols in the two constructs. The presence of the tetrafunctional cross-link desmosine was shown for all analyzed materials and its quantification revealed that the cross-linking degree of the two in vitro cross-linked materials was significantly lower than that of native elastin. Molecular dynamics simulations were performed, based on molecular species identified in the samples, to follow the formation of elastin cross-links. The results provide evidence for the significance of the GVGTP hinge region of domain 23 for the formation of elastin cross-links. Overall, this work provides important insight into structural similarities and differences between elastin-like constructs and native elastin. Furthermore, it represents a step toward the elucidation of the complex cross-linking pattern of mature elastin. PMID:25068896

Heinz, Andrea; Schräder, Christoph U; Baud, Stéphanie; Keeley, Fred W; Mithieux, Suzanne M; Weiss, Anthony S; Neubert, Reinhard H H; Schmelzer, Christian E H

2014-09-01

389

High thermal stability solution-processable narrow-band gap molecular semiconductors.  

Science.gov (United States)

A series of narrow-band gap conjugated molecules with specific fluorine substitution patterns has been synthesized in order to study the effect of fluorination on bulk thermal stability. As the number of fluorine substituents on the backbone increase, one finds more thermally robust bulk structures both under inert and ambient conditions as well as an increase in phase transition temperatures in the solid state. When integrated into field-effect transistor devices, the molecule with the highest degree of fluorination shows a hole mobility of 0.15 cm(2)/V·s and a device thermal stability of >300 °C. Generally, the enhancement in thermal robustness of bulk organization and device performance correlates with the level of C-H for C-F substitution. These findings are relevant for the design of molecular semiconductors that can be introduced into optoelectronic devices to be operated under a wide range of conditions. PMID:25347572

Liu, Xiaofeng; Hsu, Ben B Y; Sun, Yanming; Mai, Cheng-Kang; Heeger, Alan J; Bazan, Guillermo C

2014-11-19

390

Effect of paste processing on residue levels of imidacloprid, pyraclostrobin, azoxystrobin and fipronil in winter jujube.  

Science.gov (United States)

The changes of imidacloprid, pyraclostrobin, azoxystrobin and fipronil residues were studied to investigate the carryover of pesticide residues in winter jujube during paste processing. A multi-residue analytical method for winter jujube was developed based on the QuEChERS approach. The recoveries for the pesticides were between 87.5% and 116.2%. LODs ranged from 0.002 to 0.1 mg kg(-1). The processing factor (Pf) is defined as the ratio of pesticide residue concentration in the paste to that in winter jujube. Pf was higher than 1 for the removal of extra water, and other steps were generally less than 1, indicating that the whole process resulted in lower pesticide residue levels in paste. Peeling would be the critical step for pesticide removal. Processing factors varied among different pesticides studied. The results are useful to address optimisation of the processing techniques in a manner that leads to considerable pesticide residue reduction. PMID:25090100

Peng, Wei; Zhao, Liuwei; Liu, Fengmao; Xue, Jiaying; Li, Huichen; Shi, Kaiwei

2014-01-01

391

The disposal of intermediate-level radioactive liquid waste by hydraulic fracturing process  

International Nuclear Information System (INIS)

The hydraulic fracturing process is characterized by combination of the treatment with the disposal of ILLW (intermediate-level liquid waste). It is of cement solidification in deep geology stratum. First of all, it is necessary to select a suitable disposal site with detailed information on geology and hydrogeology. The process has such advantages as simple, low cost, large capacity of disposal, safe and reliable in technology. It is an attractive process of ILLW. Since 1980's, the research and the concept design of the hydraulic fracturing process have been initiated for disposal of ILLW. It is demonstrated by the field tests. The authors considered that the geological structure near Sichuan Nuclear Fuel Plant fits the disposal of ILLW by the hydraulic fracturing process

392

Role of intrinsic molecular dipole in energy level alignment at organic interfaces  

Science.gov (United States)

The energy level alignment in metal-organic and organic-organic junctions of the widely used materials tris-(8-hydroxyquinoline)aluminum (Alq3) and 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA) is investigated. The measured alignment schemes for single and bilayer films of Alq3 and NTCDA are interpreted with the integer charge transfer (ICT) model. Single layer films of Alq3 feature a constant vacuum level shift of ˜0.2-0.4 eV in the absence of charge transfer across the interface. This finding is attributed to the intrinsic dipole of the Alq3 molecule and (partial) ordering of the molecules at the interfaces. The vacuum level shift changes the onset of Fermi level pinning, as it changes the energy needed for equilibrium charge transfer across the interface.

Lindell, Linda; ?ak?r, Deniz; Brocks, Geert; Fahlman, Mats; Braun, Slawomir

2013-06-01

393

Algorithms of Two-Level Parallelization for DSMC of Unsteady Flows in Molecular Gasdynamics  

OpenAIRE

The general scheme of two-level parallelization (TLP) for direct simulation Monte Carlo of unsteady gas flows on shared memory multiprocessor computers has been described. The high efficient algorithm of parallel independent runs is used on the first level. The data parallelization is employed for the second one. Two versions of TLP algorithm are elaborated with static and dynamic load balancing. The method of dynamic processor reallocation is used for dynamic load balancing...

Bogdanov, Alexander V.; Bykov, Nick Yu; Grishin, Igor A.; Khanlarov, Gregory O.; Lukianov, German A.; Zakharov, Vladimir V.

1999-01-01

394

Molecular Mechanisms of SERT in Platelets: Regulation of Plasma Serotonin Levels  

OpenAIRE

Long before it received fame as a neurotransmitter, 5-hydroxytryptamine was recognized as a vasoconstrictor in serum and therefore termed “serotonin.” Elevated serotonin levels in the plasma have been linked to hypertension and various cardiovascular diseases. The serotonin transporter (SERT) located in the platelet plasma membrane is the fundamental regulator of plasma serotonin concentration. Intriguingly, the expression of SERT in the platelet membrane is regulated by plasma levels of ...

Mercado, Charles P.; Kilic, Fusun

2010-01-01

395

Adopted levels and derived limits for Ra-226 and the decision making processes concerning TENORM releases  

International Nuclear Information System (INIS)

A fraction of a primary dose limit can be, in general, agreed upon as a dose related level to be adopted in decision-making processes. In the case of TENORM releases, fractions of primary dose levels for 226Ra, 228Ra, and 210Po may be of particular importance to establish adopted levels and derived limits to guide decision making processes. Thus, for example, a registration level for 226Ra could be adopted at the highest portion of the natural background variation. Above such level, intervention and remedial action levels could also be adopted. All those levels would be fractions of the primary level, but translated in terms of derived limits expressed in practical units. Derived limits would then be calculated by using environmental models. In such approach 'critical groups' would have to be carefully defined and identified. In addition, the size of a critical group would be chosen to be used in environmental modeling. Site specific environmental models and parameters are desirable, though unavailable, or very difficult to obtain, in most cases. Thus, mathematical models and parameters of more generic nature are often used. A sensitive parametric analysis can make a ranking of the parameters used in a model, allowing one to choose how important each parameter will be for the model output. The paper will point out that when using the adopted levels and derived limits, as suggested above, the uncertainties and importance of the parameters entering an environmental model can make the difference for decision makers to take the right or wrong decision, as far as radiological protection is concerned. (author)

396

Supramolecular Chemistry And Self-assembly Special Feature: All-optical processing with molecular switches  

Science.gov (United States)

A gradual transition from electrical to optical networks is accompanying the rapid progress of telecommunication technology. The urge for enhanced transmission capacity and speed is dictating this trend. In fact, large volumes of data encoded on optical signals can be transported rapidly over long distances. Their propagation along specific routes across a communication network is ensured by a combination of optical fibers and optoelectronic switches. It is becoming apparent, however, that the interplay between the routing electrical stimulations and the traveling optical signals will not be able to support the terabit-per-second capacities that will be needed in the near future. Electrical inputs cannot handle the immense parallelism potentially possible with optical signals. Operating principles to control optical signals with optical signals must be developed. Molecular and supramolecular switches are promising candidates for the realization of innovative materials for information technology. Binary digits can be encoded in their chemical, electrical, or optical inputs and outputs to execute specific logic functions. We have developed a simple strategy to gate optical signals with optical signals by using a photoactive molecular switch. We have demonstrated that NAND, NOR, and NOT operations can be implemented exclusively with optical inputs and optical outputs coupling from one to three switching elements. Our remarkably simple approach to all-optical switching might lead to the development of a new generation of devices for digital processing and communication technology.

Raymo, Françisco M.; Giordani, Silvia

2002-04-01

397

Adopted levels and derived limits for Ra-226 and the decision making processes concerning TENORM releases  

International Nuclear Information System (INIS)

A fraction of a primary dose limit can be, in general, agreed upon as a dose related level to be adopted in decision-making processes. In the case of TENORM releases, fractions of primary dose levels for 226Ra, 228Ra, and 210Po may be of particular importance to establish adopted levels for 226Ra could be adopted at the highest portion of the natural background variation. Above such level, intervention and remedial action levels could also be adopted. All those levels would be fractions of the primary level, but translated in terms of derived limits expressed in practical units. Derived limits would then be calculated by using environmental models. In such approach 'critical groups' would have to be carefully defined and identified. In addition, the size of a critical group would be chosen to be used in environmental modeling. Site specific environmental models and parameters are desirable, though unavailable, or very difficult to obtain, in most cases. Thus, mathematical models and parameters of more generic nature are often used. A sensitive parametric analysis can make a ranking of the parameters used in a model, allowing one to choose how important each parameter will be for the model output. The paper will point out that when using the adopted levels and derived limits, as suggested above, the uncertainties and importance of the parameters entering an environmental model can make the difference for decision makers to take the right or wrong decision, as far as radiological protection is concerned. (author)

398

Simulation modeling of nuclear steam generator water level process--a case study  

Science.gov (United States)

Simulation modeling of the nuclear steam generator (SG) water level process in Qinshan Nuclear Power Plant (QNPP) is described in this paper. A practical methodology was adopted so that the model is both simple and accurate for control engineering implementation. The structure of the model is in the form of a transfer function, which was determined based on first-principles analysis and expert experience. The parameters of the model were obtained by taking advantage of the recorded historical response curves under the existing closed-loop control system. The results of process dimensional data verification and experimental tests demonstrate that the simulation model depicts the main dynamic characteristics of the SG water level process and is in accordance with the field recorded response curves. The model has been successfully applied to the design and test of an advanced digital feedwater control system in QNPP. PMID:10871210

Zhao; Ou; Du

2000-01-01

399

Effectiveness of sensory processing strategies on activity level in inclusive preschool classrooms  

Directory of Open Access Journals (Sweden)

Full Text Available Chien-Lin Lin,1,2 Yu-Fan Min,3 Li-Wei Chou,1,2,* Chin-Kai Lin,4,* 1Department of Physical Medicine and Rehabilitation, China Medical University Hospital, Taichung, Taiwan; 2School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan; 3Faith, Hope and Love, Center for Children and Adults With Disabilities, Taichung, Taiwan; 4Program of Early Intervention, Department of Early Childhood Education, National Taichung University of Education, Taichung, Taiwan*These authors contributed equally to this workBackground: The purpose of this study was to investigate the effectiveness of sensory processing strategies in improving the activity level of children with sensory integration dysfunction.Methods: The study used a matching-only pretest–posttest control group design, which requires random matching of sensory integration dysfunction to the corresponding intervention group (n = 18 and control group (n = 18. The intervention group comprised 3–6-year-old children who received an 8-week school-day intervention during implementation of the theme curriculum.Results: The 8-week treatment significantly reduced the activity level and foot-swinging episodes in children with sensory integration dysfunction, and obtained a medium-effect size. However, the level of improvement in the control group did not show any statistically significant change.Conclusion: Sensory processing strategies could improve activity levels in children with sensory integration dysfunction. However, this study was unable to exclude a developmental effect. The social validity results show that sensory processing strategies can be integrated into the theme curriculum and improve activity levels in children.Keywords: activity level, preschool inclusive classroom, sensory integration dysfunction, sensory processing strategy

Lin CL

2012-10-01

400

Evaluation of process alternatives for solidification of the West Valley high-level liquid wastes  

International Nuclear Information System (INIS)

The Department of Energy (DOE) established the West Valley Solidification Project (WVSP) in 1980. The project purpose is to demonstrate removal and solidification of the high-level liquid wastes (HLLW) presently stored in tanks at the Western New York Nuclear Service Center (WNYNSC), West Valley, New York. As part of this effort, the Pacific Northwest Laboratory (PNL) conducted a study to evaluate process alternatives for solidifcation of the WNYNSC wastes. Two process approaches for waste handling before solidification, together with solidification processes for four terminal and four interim waste forms, were considered. The first waste-handling approach, designated the salt/sludge separation process, involves separating the bulk of the nonradioactive nuclear waste constituents from the radioactive waste constituents, and the second waste-handling approach, designated the combined-waste process, involves no waste segregation prior to solidification. The processes were evaluated on the bases of their (1) readiness for plant startup by 1987, (2) relative technical merits, and (3) process cost. The study has shown that, based on these criteria, the salt/sludge separation process with a borosilicate glass waste form is preferred when producing a terminal waste form. It was also concluded that if an interim waste form is to be used, the preferred approach would be the combined waste process with a fused-salt waste form

401

Effect of cattle age, forage level, and corn processing on diet digestibility and feedlot performance.  

Science.gov (United States)

Three experiments were conducted to determine the effects of cattle age and dietary forage level on the utilization of corn fed whole or ground to feedlot cattle. In Exp. 1, 16 steers were used to investigate the effects of cattle age and corn processing on diet digestibility. Two cattle age categories were evaluated (weanling [254 +/- 20 kg BW] and yearling [477 +/- 29 kg BW]; eight steers per group), and corn was fed either ground or whole to each cattle age category. Cattle age and corn processing did not affect (P > 0.10) diet digestibility of DM, OM, starch, CP, NDF or ADF, and no interactions (P > 0.10) between these two factors were detected. In Exp. 2, the effects of forage level and corn processing on feedlot performance and carcass characteristics were evaluated. One hundred eighty steers (310 +/- 40 kg BW) were allotted to 24 pens, and were fed one of the following diets: high-forage (18.2% corn silage) cracked corn (HFCC); high-forage shifting corn (whole corn for the first half of the trial, then cracked corn until harvest; HFSC); high-forage whole corn (HFWC); low-forage (5.2% corn silage) cracked corn (LFCC); low-forage shifting corn (LFSC); and low-forage whole corn (LFWC). For the high-forage diets, steers fed cracked corn had 7% greater DMI than those fed whole corn, whereas for the low-forage diets, grain processing did not affect DMI (interaction; P = 0.02). No interactions (P > 0.10) between forage level and corn processing were found for ADG and G:F. Total trial ADG and G:F, and percentage of carcasses grading USDA Choice, and carcass yield grade were not affected (P > 0.10) by corn processing. Cattle with fewer days on feed grew faster and more efficiently when cracked corn was fed, whereas cattle with longer days on feed had greater ADG and G:F when corn was fed whole (interaction; P 0.10) between forage level and corn processing were detected for starch digestibility. Forage level and corn processing (grinding) did not affect (P > 0.10) diet DM, OM, starch, CP, and NDF digestibility. Processing corn did not provide additional benefits to feedlot cattle performance under these experimental conditions. PMID:15705768

Gorocica-Buenfil, M A; Loerch, S C

2005-03-01

402

Defense waste processing facility: the vitrification of high-level nuclear waste  

International Nuclear Information System (INIS)

The Defense Waste Processing Facility (DWPF) will be the United States' first production scale facility and the worlds' largest plant for the vitrification of high-level nuclear waste. The EDWPF, which is under construction at the Department of Energy's Savannah River Plant (SRP) will immobilize the highly radioactive fraction f over 33 million gallons of high-level nuclear waste. The facility is approximately 30% complete and will begin operation in 1990. Through technical and engineering innovation, the estimated cost of the facility was reduced from an original forecast of $2.3B to $910M. This estimate was refined in 1984 to $870M and has remained constant since. The Savannah River Plant's high-level wastes (HLW) are stored in underground tanks as salts, primarily sodium nitrate, and sludges, primarily metallic oxides and hydroxides. The sludges are pretreated in the waste tank farm prior to transfer to the DWPF. The salt fraction of the waste is decontaminated in the waste tank farm. This decontamination process results in a low-level waste stream which will be disposed of on the SRP site in a cement and flyash matrix. The HLW stream resulting from the decontamination process is a mixture of cesium and poteassium tetraphenyl borate salts. This stream will be processed in the DWPF to remove the organic component, combined with HLW sludges and glass frit before feeding to the DWPF melter. The DWPF will use many unique and innovative processes and items of equipment. The process is centered around a ceramic lined, slurry fed, joule-heated glass melter. The molten glass is poured into stainless steel canisters and a temporary plus inserted. After cooling, the canister is decontaminated by ''sand blasting'' with a mixture of air, water and glass frit. An upset resistance weld provides a permanent closure. The canisters will be stored on the SRP site until a repository is available

403

Molecular simulation evidence for processive motion of Trichoderma reesei Cel7A during cellulose depolymerization  

Science.gov (United States)

We present free energy calculations for the Trichoderma reesei Cel7A (cellobiohydrolase I) linker peptide from molecular dynamics simulations directed towards understanding the linker role in cellulose hydrolysis. The calculations predict an energy storage mechanism of the linker under stretching/compression that is consistent with processive depolymerization. The linker exhibits two stable states at lengths of 2.5 nm and 5.5 nm during extension/compression, with a free energy difference of 10.5 kcal/mol between the two states separated by an energy barrier. The switching between stable states supports the hypothesis that the linker peptide has the capacity to store energy in a manner similar to a spring.

Zhao, Xiongce; Rignall, Tauna R.; McCabe, Clare; Adney, William S.; Himmel, Michael E.

2008-07-01

404

Mapping Variable Ring Polymer Molecular Dynamics: A Path-Integral Based Method for Nonadiabatic Processes  

CERN Document Server

We introduce mapping-variable ring polymer molecular dynamics (MV-RPMD), a model dynamics for the direct simulation of multi-electron processes. An extension of the RPMD idea, this method is based on an exact, imaginary time path-integral representation of the quantum Boltzmann operator using continuous Cartesian variables for both electronic states and nuclear degrees of freedom. We demonstrate the accuracy of the MV-RPMD approach in calculations of real-time, thermal correlation functions for a range of two-state single-mode model systems with different coupling strengths and asymmetries. Further, we show that the ensemble of classical trajectories employed in these simulations preserves the Boltzmann distribution and provides a direct probe into real-time coupling between electronic state transitions and nuclear dynamics.

Ananth, Nandini

2013-01-01

405

Charge separation process in water clusters containing HCl. Molecular dynamics study using semiempirical hamiltonians.  

Science.gov (United States)

The acid dissociation of HCl in water clusters was studied using the PM3-MAIS model in a direct molecular dynamic simulations framework. Several trajectories for each cluster size were computed to improve the sampling on the potential energy surface and to increase the statistical significance of our study. We have analyzed the emergence of well-defined hydration structures around the ions and the effect they have on the charge separation process. Surface and bulk solvation situations are examined for both ions in terms of the competing circumstances for water molecules in the cluster. Our results show that the prevailing situation in all these clusters is a water mediated interaction between the ions. This situation is related to the significant interplay of several factors such as charge transfer occurring between the ions and their first hydration shells. Our results show that no significant charge redistribution occurs during the Eigen-Zundel transformation. PMID:20677821

Arillo Flores, Oscar Ivan; Bernal-Uruchurtu, Margarita I

2010-09-01