WorldWideScience

Sample records for molecular level processes

  1. Single molecular level analysis and processing in nanochannels.

    Science.gov (United States)

    Yamamoto, Takatoki

    2012-01-01

    Recent advances in nanofluidic technologies have enabled devices to be fabricated that integrate nanochannels with at least one dimension smaller than several hundred nanometers. Since this dimension is close to the sizes of biomolecules such as DNA, proteins, and other biomolecules, it opens up new scientific and technological fields based on analysis and manipulation of single molecules. This paper reviews the current state of knowledge regarding single molecular level analysis and processing in nanochannels, particularly experimental findings in this area. While there have been many theoretical and molecular simulation studies, this paper surveys experimental studies. Following a brief survey of techniques for fabricating nanochannels, we review fundamental studies of single molecule behavior and manipulation in nanochannels. We then discuss important transport phenomena of single molecules in nanochannels. Finally, the emerging challenge of electrical single-molecule detection and its possible applications are highlighted. PMID:22652886

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

    International Nuclear Information System (INIS)

    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 inry and experiment will provide the base information needed to scale from the molecular level to the microscopic grain level minerals

  3. Mathematical model and calculation algorithm of micro and meso levels of separation process of gaseous mixtures in molecular sieves

    Science.gov (United States)

    Umarova, Zhanat; Botayeva, Saule; Yegenova, Aliya; Usenova, Aisaule

    2015-05-01

    In the given article, the main thermodynamic aspects of the issue of modeling diffusion transfer in molecular sieves have been formulated. Dissipation function is used as a basic notion. The differential equation, connecting volume flow with the change of the concentration of catchable component has been derived. As a result, the expression for changing the concentration of the catchable component and the coefficient of membrane detecting has been received. As well, the system approach to describing the process of gases separation in ultra porous membranes has been realized and micro and meso-levels of mathematical modeling have been distinguished. The non-ideality of the shared system is primarily taken into consideration at the micro-level and the departure from the diffusion law of Fick has been taken into account. The calculation method of selectivity considering fractal structure of membranes has been developed at the meso level. The calculation algorithm and its software implementation have been suggested.

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

    International Nuclear Information System (INIS)

    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

  5. Design of structure of zeolitic catalysts on a molecular level as a key to highly effective industrial processes.

    Czech Academy of Sciences Publication Activity Database

    Sazama, Petr; Wichterlová, Blanka; D?de?ek, Ji?í; Tvar?žková, Zdenka; Sathu, Naveen Kumar; Kreibich, Viktor; Sobalík, Zden?k

    Prague : J. Heyrovský Institute of Physical Chemistry of the ASCR, v.v.i, 2011 - (Horá?ek, M.). P5 ISBN 978-80-87351-14-7. [Czech-Italian- Spanish Symposium on Molecular Sieves and Catalysis /4./. 15.06.2011-18.06.2011, Liblice] Institutional research plan: CEZ:AV0Z40400503 Keywords : zeolites * ZSM-5 Subject RIV: CF - Physical ; Theoretical Chemistry

  6. Changes of anabolic processes at the cellular and molecular level in chronic wounds under topical negative pressure can be revealed by transcriptome analysis.

    Science.gov (United States)

    Leffler, Mareike; Derrick, Kathleen L; McNulty, Amy; Malsiner, Caye; Dragu, Adrian; Horch, Raymund E

    2011-07-01

    Chronic wounds--as defined by the World Union of Wound Healing Societies (WUWHS)--are a considerable worldwide health care expense and impair quality of life. In order for chronic wounds to heal, these wounds must be transformed to a more acute state to begin the healing process. Topical negative pressure (TNP) with reticulated open cell foam (ROCF) is known to promote healing in certain types of chronic wounds. However, little is known about changes at the cellular or molecular level in wounds under various treatments, especially under the physical forces induced to tissue by TNP. In the current study, chronic wound samples were obtained during routine wound debridements prior to treatment and 7-12 days after initiating TNP with a continuous setting at -125 mmHg. Whole genome transcriptome microarray analyses were performed on samples to better understand how TNP with ROCF affects these types of wounds. It was found that more genes were expressed following TNP with ROCF as compared to before therapy and to normal, non-wounded tissue. In this study, we show that TNP with ROCF transforms the chronic wound from its inflammation (non-healing) state into more of a progressive, healing phenotype from a molecular point of view with expression of genes that are commonly associated with these terms. PMID:20716124

  7. Enzyme optimization for next level molecular computing

    Science.gov (United States)

    W?siewicz, Piotr; Malinowski, Michal; Plucienniczak, Andrzej

    2006-10-01

    The main concept of molecular computing depends on DNA self-assembly abilities and on modifying DNA with the help of enzymes during genetic operations. In the typical DNA computing a sequence of operations executed on DNA strings in parallel is called an algorithm, which is also determined by a model of DNA strings. This methodology is similar to the soft hardware specialized architecture driven here by heating, cooling and enzymes, especially polymerases used for copying strings. As it is described in this paper the polymerase Taq properties are changed by modifying its DNA sequence in such a way that polymerase side activities together with peptide chains, responsible for destroying amplified strings, are cut off. Thus, it introduces the next level of molecular computing. The genetic operation execution succession and the given molecule model with designed nucleotide sequences produce computation results and additionally they modify enzymes, which directly influence on the computation process. The information flow begins to circulate. Additionally, such optimized enzymes are more suitable for nanoconstruction, because they have only desired characteristics. The experiment was proposed to confirm the possibilities of the suggested implementation.

  8. Quantum Control of Molecular Processes

    CERN Document Server

    Shapiro, Moshe

    2012-01-01

    Written by two of the world's leading researchers in the field, this is a systematic introduction to the fundamental principles of coherent control, and to the underlying physics and chemistry.This fully updated second edition is enhanced by 80% and covers the latest techniques and applications, including nanostructures, attosecond processes, optical control of chirality, and weak and strong field quantum control. Developments and challenges in decoherence-sensitive condensed phase control as well as in bimolecular control are clearly described.Indispensable for atomic, molecular and chemical

  9. Dynamical processes in atomic and molecular physics

    CERN Document Server

    Ogurtsov, Gennadi

    2012-01-01

    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

  10. The Accuracy of Molecular Processes

    Science.gov (United States)

    Stavans, Joel

    Recombination is arguably one of the most fundamental mechanisms driving genetic diversity during evolution. Recombination takes place in one way or another from viruses such as HIV and polio, to bacteria, and finally to man. In both prokaryotes and eukaryotes, homologous recombination is assisted by enzymes, recombinases, that promote the exchange of strands between two segments of DNA, thereby creating new genetic combinations. In bacteria, homologous recombination takes place as a pathway for the repair of DNA lesions and also during horizontal or lateral gene transfer processes, in which cells take in exogenous pieces of DNA. This allows bacteria to evolve rapidly by acquiring large sequences of DNA, a process which would take too long by gene duplications and single mutations. I will survey recent results on the fidelity of homologous recombination as catalyzed by the bacterial recombinase RecA. These results show discrimination up to the level of single base mismatches, during the initial stages of the recombination process. A cascaded kinetic proofreading process is proposed to explain this high discrimination. Kinetic proofreading ideas are also reviewed.

  11. Synthesis and spectral investigations of a new dyad with spiropyran and fluorescein units: toward information processing at the single molecular level.

    Science.gov (United States)

    Guo, Xuefeng; Zhang, Deqing; Zhou, Yucheng; Zhu, Daoben

    2003-07-11

    A new dyad 1 with two spiropyran units as the photochromic acceptors and one fluorescein unit as the fluorescent donor was synthesized and characterized. External inputs (ultraviolet light, visible light, and proton) induce the reversible changes of the structure and, concomitantly, the absorption spectrum of dyad 1 due to the presence of two spiropyran units. Only the absorption spectrum of the ME form of the spiropyran units in dyad 1 has large spectral overlap with the fluorescence spectrum of the fluorescein unit. Thus, the fluorescence intensity of dyad 1 is modulated by reversible conversion among the three states of the photochromic spiropyran units and the fluorescence resonance energy transfer (FRET) between the ME form and the fluorescein unit. Based on the fact that dyad 1 could "read out" three external input signals (ultraviolet light, visible ligh,t and proton) and "write" a compatible specific output signal (fluorescence intensity), dyad 1 described here can be considered to perform an integrated circuit function with one OR and one AND interconnected logic gates. The present results demonstrate an efficient strategy for elaborating and transmitting information at the single molecular level. PMID:12839463

  12. Designing an university-level module on molecular imaging chemistry

    International Nuclear Information System (INIS)

    Full text: Why do we need radiopharmacy, radiopharmacy, radiopharmacy training? In this post-genomic era, molecular imaging has gain tremendous interest not only amongst physicians but also from biologists, chemists, physicists, engineers, statisticians, pharmaceutical companies and even from governments. There is no doubt that nuclear medicine has been engaged in molecular medicine more than one decade ago. Positron emission tomography (PET) has reawaken interest in long forgotten radiopharmacy. Only major hospitals in the developed countries have invested in the development of dedicated radiopharmacy laboratory and training or recruitment of radiopharmacist. But PET has forced nuclear medicine to create a radiopharmacy unit and adopt radiopharmacy guidelines such as good radiopharmaceutical practice (GRPP) and good manufacturing practice (GMP). It is compounded by the fact that SPECT radiopharmaceutical chemistry has advanced significantly for both diagnostics and therapeutics, which calls for a high level of understanding on radiopharmaceutical chemistry and technical know-how. These factors eventually lead to introduction of tran ing program, courses and degree program. The most striking examples will be European Association of Nuclear Medicine (EANM) radiopharmacy courses and a series of IAEA activities on GRPP, GMP and technologist training programs. Various forms of training or education program can be formulated for various levels, starting from basic radiopharious levels, starting from basic radiopharmacy course to PhD program, depending on the following factors; (1) National interest and policies on bio/medical sector; (2) Size of the nuclear medicine community in the respective country; (3) Institution interest and policies; and (4) Existing infrastructure and programs. Current Radiopharmacy Education in Singapore: In Singapore, all of the major nuclear medicine centers are supervised by radiopharmacists with PhD degree. All of the nuclear medicine technologists in the major centers have got training in radiopharmacy both in theory and hands-on practice. Final-year radiology students in Polytechnic have to go through a series of lectures on radiopharmacy and also practicals in hospital radiopharmacy laboratory. But due to the Government's initiatives on biomedical industries and also due to a global trend, interest in bio/medical imaging is rising among scientists and students. There is a need to fulfil this demand by introducing new course or modules at the University level. Designing an university-level module on molecular imaging chemistry: In National University of Singapore, a graduate student (MSc and PhD) level 5 module on ''Medical Imaging'' has already been introduced and a new module on ''Molecular Imaging Chemistry'' will be introduced soon. A module of this kind should serve as a link between chemistry, molecular imaging and clinical application with emphasis on chemical probe design. And should introduce contemporary topics and emerging concepts in chemistry related to molecular imaging. A brief introduction on different modalities of molecular imaging and principles of biomedical imaging should be introduced including principles of medical imaging equipment. How this knowledge will direct the chemical synthesis should be highlighted (lead directed synthesis). There should be a coverage on pharmacology and drug discovery process as imaging probes could be considered as drugs. Here is an example of an outline for such module: - Introduction: - What is molecular imaging? - Why molecular imaging? - What is biomedical imaging? - Different modalities of molecular imaging; - Different types of molecular imaging; - In vitro, ex vivo, in vivo imaging; Drug discovery process; - Pharmacological basis. Molecular Imaging Chemistry: - general construct of imaging probe (molecular reporter system); - Bioimaging factors influencing chemical probe synthesis; Optical imaging probes; - Radioimaging probes; - MR contrast agents; - Probes for other modalities, X ray, ultrasound, etc. Examples of practical application

  13. 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.

  14. From molecular activities and processes to biological function.

    Science.gov (United States)

    van Helden, J; Naim, A; Lemer, C; Mancuso, R; Eldridge, M; Wodak, S J

    2001-03-01

    This paper describes how biological function can be represented in terms of molecular activities and processes. It presents several key features of a data model that is based on a conceptual description of the network of interactions between molecular entities within the cell and between cells. This model is implemented in the aMAZE database that presently deals with information on metabolic pathways, gene regulation, sub- or supracellular locations, and transport. It is shown that this model constitutes a useful generalisation of data representations currently implemented in metabolic pathway databases, and that it can furthermore include multiple schemes for categorising and classifying molecular entities, activities, processes and localisations. In particular, we highlight the flexibility offered by our system in representing multiple molecular activities and their control, in viewing biological function at different levels of resolution and in updating this view as our knowledge evolves. PMID:11465065

  15. 1982 bibliography of atomic and molecular processes

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  16. 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

  17. 1984 Bibliography of atomic and molecular processes

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  18. 1985 bibliography of atomic and molecular processes

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. Experimental determination of enthalpies of solution of tetraphenyl porphyrin (TPP) and some metal derivatives, in chloroform: interpretation of the solvation processes at a molecular level.

    Science.gov (United States)

    Gamboa, Minerva; Campos, Myriam; Torres, Luis Alfonso

    2010-01-18

    The enthalpies of solution, Delta(sol)H(m), for 5,10,15,20-tetraphenylporphine (CA registry number 917-23-7, TPP), 5,10,15,20-tetraphenylporphine of Co(II), Ni(II), Cu(II), and Zn(II) (to be written as CoTPP, NiTPP, CuTPP, and ZnTPP) in chloroform, were calorimetrically measured at T = 298 K in the concentration ranging from 3.5 x 10(-5) to 2.8 x 10(-4) mol.kg(-1). Through the linear extrapolation of the experimental data, corresponding values at infinite dilution were determined as: Delta(sol)H(m) (ZnTPP) = (55.5 +/- 0.2) kJ x mol(-1), Delta(sol)H(m) (CoTPP) = (36.9 +/- 0.2) kJ x mol(-1), Delta(sol)H(m) (TPP) = (25.7 +/- 0.6) kJ x mol(-1), Delta(sol)H(m) (NiTPP) = (15.6 +/- 0.1) kJ x mol(-1), and Delta(sol)H(m) (CuTPP) = (15.6 +/- 0.1) kJ x mol(-1). The enthalpies of solvation for the five compounds were also determined using the previously published values for the enthalpy of sublimation, as well as complementary data from the literature. The values obtained are as follows: Delta(solv)H(m)(TPP) = -(158.3 +/- 2.1) kJ x mol(-1), Delta(solv)H(m)(CoTPP) = -(154.1 +/- 2.0) kJ x mol(-1), Delta(solv)H(m)(CuTPP) = -(149.4 +/- 5.0) kJ x mol(-1) Delta(solv)H(m)(NiTPP) = -(141.4 +/- 4.0) kJ x mol(-1), and Delta(solv)H(m)(ZnTPP) = -(140.5 +/- 3.0) kJ x mol(-1). The results are analyzed in relation to several molecular properties such as ionic radius, electronic spectra, and Connolly surface. An explanation of the observed trends for solvation enthalpies is proposed. PMID:20000579

  6. Reasoning across Ontologically Distinct Levels: Students' Understandings of Molecular Genetics

    Science.gov (United States)

    Duncan, Ravit Golan; Reiser, Brian J.

    2007-01-01

    In this article we apply a novel analytical framework to explore students' difficulties in understanding molecular genetics--a domain that is particularly challenging to learn. Our analytical framework posits that reasoning in molecular genetics entails mapping across ontologically distinct levels--an information level containing the genetic…

  7. Quantum mechanics of molecular rate processes

    CERN Document Server

    Levine, Raphael D

    2011-01-01

    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.

  8. 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.

  9. Molecular-level understanding of the carbonisation of polysaccharides.

    Science.gov (United States)

    Shuttleworth, Peter S; Budarin, Vitaliy; White, Robin J; Gun'ko, Vladimir M; Luque, Rafael; Clark, James H

    2013-07-01

    Understanding of both the textural and functionality changes occurring during (mesoporous) polysaccharide carbonisation at the molecular level provides a deeper insight into the whole spectrum of material properties, from chemical activity to pore shape and surface energy, which is crucial for the successful application of carbonaceous materials in adsorption, catalysis and chromatography. Obtained information will help to identify the most appropriate applications of the carbonaceous material generated during torrefaction and different types of pyrolysis processes and therefore will be important for the development of cost- and energy-efficient zero-waste biorefineries. The presented approach is informative and semi-quantitative with the potential to be extended to the formation of other biomass-derived carbonaceous materials. PMID:23740856

  10. Evidence for systems-level molecular mechanisms of tumorigenesis

    Directory of Open Access Journals (Sweden)

    Capellá Gabriel

    2007-06-01

    Full Text Available Abstract Background Cancer arises from the consecutive acquisition of genetic alterations. Increasing evidence suggests that as a consequence of these alterations, molecular interactions are reprogrammed in the context of highly connected and regulated cellular networks. Coordinated reprogramming would allow the cell to acquire the capabilities for malignant growth. Results Here, we determine the coordinated function of cancer gene products (i.e., proteins encoded by differentially expressed genes in tumors relative to healthy tissue counterparts, hereafter referred to as "CGPs" defined as their topological properties and organization in the interactome network. We show that CGPs are central to information exchange and propagation and that they are specifically organized to promote tumorigenesis. Centrality is identified by both local (degree and global (betweenness and closeness measures, and systematically appears in down-regulated CGPs. Up-regulated CGPs do not consistently exhibit centrality, but both types of cancer products determine the overall integrity of the network structure. In addition to centrality, down-regulated CGPs show topological association that correlates with common biological processes and pathways involved in tumorigenesis. Conclusion Given the current limited coverage of the human interactome, this study proposes that tumorigenesis takes place in a specific and organized way at the molecular systems-level and suggests a model that comprises the precise down-regulation of groups of topologically-associated proteins involved in particular functions, orchestrated with the up-regulation of specific proteins.

  11. 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

  12. The challenges for molecular nutrition research 4: the “nutritional systems biology level”

    OpenAIRE

    Ommen, Ben; Cavallieri, Duccio; Roche, Helen M.; Klein, Ulla I.; Daniel, Hannelore

    2008-01-01

    Nutritional systems biology may be defined as the ultimate goal of molecular nutrition research, where all relevant aspects of regulation of metabolism in health and disease states at all levels of its complexity are taken into account to describe the molecular physiology of nutritional processes. The complexity spans from intracellular to inter-organ dynamics, and involves iterations between mathematical modelling and analysis employing all profiling methods and other biological read-outs. O...

  13. PLANCK LFI Level 1 Processing During Operations

    Science.gov (United States)

    Morisset, N.; Rohlfs, R.; Türler, M.; Meharga, M.; Binko, P.; Beck, M.; Frailis, M.; Zacchei, A.; Galeotta, S.

    2008-08-01

    The PLANCK satellite with two on-board instruments, a Low Frequency Instrument (LFI) and a High Frequency Instrument (HFI) is foreseen to be launched in August 2008 with Ariane 5. The Data Processing Centre (DPC) in Trieste, Italy for LFI is responsible for processing the PLANCK LFI data. The ISDC data centre in Switzerland is responsible for developing/installing and maintaining the software for the LFI Level 1 data processing presented here. The main tasks of the Level 1 processing are to retrieve the daily available consolidated scientific and housekeeping (HK) data of the LFI instrument from the Mission Operation Centre in Darmstadt (MOC); to sort them by time and by type (detector, observing mode, etc...); to extract the spacecraft attitude information from auxiliary files; to flag the data according to several criteria; and to archive the resulting Time Ordered Information (TOI). The TOI data generated by the level 1 pipeline are the input for the more scientific LFI level 2 processing. The TOI are first stored in FITS format and then ingested into the Data Management Component (DMC) system, which is the interface to the LFI DPC database. In addition, the ISDC also developed software tools to display and perform a quick look analysis of the data.

  14. Towards an Upper-Level Ontology for Molecular Biology

    OpenAIRE

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

    2006-01-01

    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.

  15. 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)

  16. Features, Events, and Processes: system Level

    Energy Technology Data Exchange (ETDEWEB)

    D. McGregor

    2004-10-15

    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).

  17. A Multi-step and Multi-level approach for Computer Aided Molecular Design

    DEFF Research Database (Denmark)

    A general multi-step approach for setting up, solving and solution analysis of computer aided molecular design (CAMD) problems is presented. The approach differs from previous work within the field of CAMD since it also addresses the need for a computer aided problem formulation and result analysis. The problem formulation step incorporates a knowledge base for the identification and setup of the design criteria. Candidate compounds are identified using a multi-level generate and test CAMD solution algorithm capable of designing molecules having a high level of molecular detail. A post solution step using an Integrated Computer Aided System (ICAS) for result analysis and verification is included in the methodology. Keywords: CAMD, separation processes, knowledge base, molecular design, solvent selection, substitution, group contribution, property prediction, ICAS Introduction The use of Computer Aided Molecular Design (CAMD) for the identification of compounds having specific physic...

  18. Level crossings and other level functionals of stationary Gaussian processes

    CERN Document Server

    Kratz, M F

    2006-01-01

    This paper presents a synthesis on the mathematical work done on level crossings of stationary Gaussian processes, with some extensions. The main results [(factorial) moments, representation into the Wiener Chaos, asymptotic results, rate of convergence, local time and number of crossings] are described, as well as the different approaches [normal comparison method, Rice method, Stein-Chen method, a general $m$-dependent method] used to obtain them; these methods are also very useful in the general context of Gaussian fields. Finally some extensions [time occupation functionals, number of maxima in an interval, process indexed by a bidimensional set] are proposed, illustrating the generality of the methods. A large inventory of papers and books on the subject ends the survey.

  19. 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

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

    Directory of Open Access Journals (Sweden)

    Dirk Zahn

    2013-08-01

    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

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

    OpenAIRE

    Dirk Zahn

    2013-01-01

    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 mater...

  2. Solvating atomic level fine-grained proteins in supra-molecular level coarse-grained water for molecular dynamics simulations.

    Science.gov (United States)

    Riniker, Sereina; Eichenberger, Andreas P; van Gunsteren, Wilfred F

    2012-08-01

    Simulation of the dynamics of a protein in aqueous solution using an atomic model for both the protein and the many water molecules is still computationally extremely demanding considering the time scale of protein motions. The use of supra-atomic or supra-molecular coarse-grained (CG) models may enhance the computational efficiency, but inevitably at the cost of reduced accuracy. Coarse-graining solvent degrees of freedom is likely to yield a favourable balance between reduced accuracy and enhanced computational speed. Here, the use of a supra-molecular coarse-grained water model that largely preserves the thermodynamic and dielectric properties of atomic level fine-grained (FG) water in molecular dynamics simulations of an atomic model for four proteins is investigated. The results of using an FG, a CG, an implicit, or a vacuum solvent environment of the four proteins are compared, and for hen egg-white lysozyme a comparison to NMR data is made. The mixed-grained simulations do not show large differences compared to the FG atomic level simulations, apart from an increased tendency to form hydrogen bonds between long side chains, which is due to the reduced ability of the supra-molecular CG beads that represent five FG water molecules to make solvent-protein hydrogen bonds. But, the mixed-grained simulations are at least an order of magnitude faster than the atomic level ones. PMID:22797564

  3. Molecular-level assemblies on metal oxide surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Schoonover, J.R.; Bignozzi, C. [Univ. of Ferrara (Italy); Meyer, T. [Univ. of North Carolina, Chapel Hill, NC (United States)

    1996-07-01

    This is the final report of a one-year, Laboratory-Directed Research and Development project at the Los Alamos National Laboratory (LANL). The objective of this project was to explore molecular-level assemblies based on polypyridyl transition metal complexes attached to metal oxide surfaces to provide the basis for applications such as energy conversion and electricity generation, photoremediation of hazardous waste, chemical sensors, and optical storage and photorefractive devices for communications and optical computing. We have elucidated the fundamental factors that determine the photochemistry and photophysics of a series of these photoactive inorganic complexes in solution and on metal oxide substrates by exploiting our unique transient laser capabilities. This data is being utilized to design and fabricate molecular-level photonic devices. The rich chemistry of transition metal polypyridyl complexes can be utilized to prepare molecular assemblies having well-defined redox or excited-state properties that can be finely tuned to produce desired materials properties. We plan to explore other novel applications such as photorefractive switches and optical sensors using this molecular engineering approach.

  4. Wafer level 3-D ICs process technology

    CERN Document Server

    Tan, Chuan Seng; Reif, L Rafael

    2009-01-01

    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.

  5. Molecular processes in plasmas collisions of charged particles with molecules

    CERN Document Server

    Itikawa, Yukikazu

    2007-01-01

    Molecular Processes in Plasmas describes elementary collision processes in plasmas, particularly those involving molecules or molecular ions. Those collision processes (called molecular processes) maintain plasmas, produce reactive species and emissions, and play a key role in energy balance in plasmas or more specifically in determining the energy distribution of plasma particles. Many books on plasma physics mention the elementary processes, but normally rather briefly. They only touch upon the general feature or fundamental concept of the collision processes. On the other hand, there are many books on atomic and molecular physics, but most of them are too general or too detailed to be useful to people in the application fields. The present book enumerates all the possible processes in the collisions of electrons, as well as ions, with molecules. For each process, a compact but informative description of its characteristics is given together with illustrative examples. Since the author has much experience a...

  6. Molecular simulation of non-equilibrium methane hydrate decomposition process

    International Nuclear Information System (INIS)

    Graphical abstract: Highlights: ? Decomposition of methane hydrate is studied with molecular dynamics simulations. ? Simulations are performed under adiabatic conditions (no thermostats). ? The effects of heat and mass transfer during the decomposition are observed. ? Temperature gradients are established as the hydrate decomposes. ? Intrinsic reaction kinetics picture of hydrate dissociation is revisited. - Abstract: We recently performed constant energy molecular dynamics simulations of the endothermic decomposition of methane hydrate in contact with water to study phenomenologically the role of mass and heat transfer in the decomposition rate [S. Alavi, J.A. Ripmeester, J. Chem. Phys. 132 (2010) 144703]. We observed that with the progress of the decomposition front temperature gradients are established between the remaining solid hydrate and the solution phases. In this work, we provide further quantitative macroscopic and molecular level analysis of the methane hydrate decomposition process with an emphasis on elucidating microscopic details and how they affect the predicted rate of methane hydrate decomposition in natural methane hydrate reservoirs. A quantitative criterion is used to characterize the decomposition of the hydrate phase at different times. Hydrate dissociation occurs in a stepwise fashion with rows of sI cages parallel to the interface decomposing simultaneously. The correlations between decomposition times of subsequent layers of the hys of subsequent layers of the hydrate phase are discussed.

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

    Science.gov (United States)

    Geckeis, Horst; Rabung, Thomas

    2008-12-12

    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

  8. A Process Calculus for Molecular Interaction Maps

    OpenAIRE

    Roberto Barbuti; Andrea Maggiolo-Schettini; Paolo Milazzo; Giovanni Pardini; Aureliano Rama

    2009-01-01

    We present the MIM calculus, a modeling formalism with a strong biological basis, which provides biologically-meaningful operators for representing the interaction capabilities of molecular species. The operators of the calculus are inspired by the reaction symbols used in Molecular Interaction Maps (MIMs), a diagrammatic notation used by biologists. Models of the calculus can be easily derived from MIM diagrams, for which an unambiguous and executable interpretation is thus...

  9. Capillary leveling of stepped films with inhomogeneous molecular mobility

    CERN Document Server

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

    2013-01-01

    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-...

  10. The challenges for molecular nutrition research 4: the "nutritional systems biology level".

    Science.gov (United States)

    van Ommen, Ben; Cavallieri, Duccio; Roche, Helen M; Klein, Ulla I; Daniel, Hannelore

    2008-12-01

    Nutritional systems biology may be defined as the ultimate goal of molecular nutrition research, where all relevant aspects of regulation of metabolism in health and disease states at all levels of its complexity are taken into account to describe the molecular physiology of nutritional processes. The complexity spans from intracellular to inter-organ dynamics, and involves iterations between mathematical modelling and analysis employing all profiling methods and other biological read-outs. On the basis of such dynamic models we should be enabled to better understand how the nutritional status and nutritional challenges affect human metabolism and health. Although the achievement of this proposition may currently sound unrealistic, many initiatives in theoretical biology and biomedical sciences work on parts of the solution. This review provides examples and some recommendations for the molecular nutrition research arena to move onto the systems level. PMID:18825427

  11. The challenges for molecular nutrition research 4: the “nutritional systems biology level”

    Science.gov (United States)

    Cavallieri, Duccio; Roche, Helen M.; Klein, Ulla I.; Daniel, Hannelore

    2008-01-01

    Nutritional systems biology may be defined as the ultimate goal of molecular nutrition research, where all relevant aspects of regulation of metabolism in health and disease states at all levels of its complexity are taken into account to describe the molecular physiology of nutritional processes. The complexity spans from intracellular to inter-organ dynamics, and involves iterations between mathematical modelling and analysis employing all profiling methods and other biological read-outs. On the basis of such dynamic models we should be enabled to better understand how the nutritional status and nutritional challenges affect human metabolism and health. Although the achievement of this proposition may currently sound unrealistic, many initiatives in theoretical biology and biomedical sciences work on parts of the solution. This review provides examples and some recommendations for the molecular nutrition research arena to move onto the systems level. PMID:18825427

  12. Improving Molecular Level Chemical Speciation of Organic Aerosols

    Science.gov (United States)

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

    2013-12-01

    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.

  13. Binaural processing of modulated interaural level differences

    DEFF Research Database (Denmark)

    Thompson, Eric Robert; Dau, Torsten

    2008-01-01

    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.

  14. VUV diagnostic of electron impact processes in low temperature molecular hydrogen plasma

    CERN Document Server

    Komppula, J

    2015-01-01

    Novel methods for diagnostics of molecular hydrogen plasma processes, such as ionization, production of high vibrational levels, dissociation of molecules via excitation to singlet and triplet states and production of metastable states, are presented for molecular hydrogen plasmas in corona equilibrium. The methods are based on comparison of rate coefficients of plasma processes and optical emission spectroscopy of lowest singlet and triplet transitions, i.e. Lyman-band ($B^1\\Sigma^+_u \\rightarrow X^1\\Sigma^+_g$) and molecular continuum ($a^3\\Sigma^+_g \\rightarrow b^3\\Sigma^+_u$), of the hydrogen molecule in VUV wavelength range. Comparison of rate coefficients of spin-allowed and/or spin-forbidden excitations reduces the uncertainty caused by the non-equilibrium distributions of electron energy and molecular vibrational level, which are typically known poorly in plasma sources. The described methods are applied to estimate the rates of various plasma processes in a filament arc discharge.

  15. Molecular solution processing of metal chalcogenide thin film solar cells

    Science.gov (United States)

    Yang, Wenbing

    The barrier to utilize solar generated electricity mainly comes from their higher cost relative to fossil fuels. However, innovations with new materials and processing techniques can potentially make cost effective photovoltaics. One such strategy is to develop solution processed photovoltaics which avoid the expensive vacuum processing required by traditional solar cells. The dissertation is mainly focused on two absorber material system for thin film solar cells: chalcopyrite CuIn(S,Se)2 (CISS) and kesterite Cu2ZnSn(S,Se) 4 organized in chronological order. Chalcopyrite CISS is a very promising material. It has been demonstrated to achieve the highest efficiency among thin film solar cells. Scaled-up industry production at present has reached the giga-watt per year level. The process however mainly relies on vacuum systems which account for a significant percentage of the manufacturing cost. In the first section of this dissertation, hydrazine based solution processed CISS has been explored. The focus of the research involves the procedures to fabricate devices from solution. The topics covered in Chapter 2 include: precursor solution synthesis with a focus on understanding the solution chemistry, CISS absorber formation from precursor, properties modification toward favorable device performance, and device structure innovation toward tandem device. For photovoltaics to have a significant impact toward meeting energy demands, the annual production capability needs to be on TW-level. On such a level, raw materials supply of rare elements (indium for CIS or tellurium for CdTe) will be the bottleneck limiting the scalability. Replacing indium with zinc and tin, earth abundant kesterite CZTS exhibits great potential to reach the goal of TW-level with no limitations on raw material availability. Chapter 3 shows pioneering work towards solution processing of CZTS film at low temperature. The solution processed devices show performances which rival vacuum-based techniques and is partially attributed to the ease in controlling composition and CZTS phase through this technique. Based on this platform, comprehensive characterization on CZTS devices is carried out including solar cells and transistors. Especially defects properties are exploited in Chapter 4 targeting to identify the limiting factors for further improvement on CZTS solar cells efficiency. Finally, molecular structures and precursor solution stability have been explored, potentially to provide a universal approach to process multinary compounds.

  16. Method of processing low level radioactive wastes

    International Nuclear Information System (INIS)

    Purpose: To enable to dispose a great amount of low level radioactive wastes with safety in the process of burying underground radioactive wastes tightly sealed in vessels. Method: Water shield walls surrounding the boundary of a disposal site are constructed by the method of successively repeating the steps of digging out shafts holes with the width corresponding to the wall thickness and reaching the water impermeable layer of the disposal site, putting iron wire cages into the holes and then spiking concretes. Then, vertical shafts each of a rectangular transversal section are dug out in the disposal site surrounded with the walls with an appropriate gap from the wall. Then, after accommodating vessels containing low level radioactive wastes tightly shield therein in the shafts, stabilizing liquid filled in the shafts is replaced with self-curing stabilizing liquid, by which radioactive wastes can be disposed with safety being covered around the periphery thereof and with the outside of them being surrounded with the water shield walls. (Horiuchi, T.)

  17. Key processes from tree to stand level

    International Nuclear Information System (INIS)

    Changes in six factors have been identified as having potential major future impacts on the productivity and survival of forest trees and stands. These factors are atmospheric carbon dioxide concentration, tropospheric ozone concentration, mean annual air temperature and precipitation, extremes in temperature and precipitation, and levels of ultraviolet radiation. Except for precipitation, all of these factors are expected to increase with climatic change. However, the likelihood of their increase or change ranges from the given to the unknown. The way in which one or more of these factors might individually or in combination affect the productivity and survival of trees is discussed, and particularly sensitive physiological processes are identified. For example, increases in winter temperature and a doubling of CO2 will result in early budburst in many species and therefore increase the risk of frost damage. In other species or locations, warm winters may mean insufficient chilling hours and the requirements for release from bud dormancy may not be met. The interaction of these processes with current species distribution, genotype selection, and management alternatives is reviewed. 52 refs., 1 fig., 1 tab

  18. 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.

  19. Molecular epidemiology biomarkers-Sample collection and processing considerations

    International Nuclear Information System (INIS)

    Biomarker studies require processing and storage of numerous biological samples with the goals of obtaining a large amount of information and minimizing future research costs. An efficient study design includes provisions for processing of the original samples, such as cryopreservation, DNA isolation, and preparation of specimens for exposure assessment. Use of standard, two-dimensional and nanobarcodes and customized electronic databases assure efficient management of large sample collections and tracking results of data analyses. Standard operating procedures and quality control plans help to protect sample quality and to assure validity of the biomarker data. Specific state, federal and international regulations are in place regarding research with human samples, governing areas including custody, safety of handling, and transport of human samples. Appropriate informed consent must be obtained from the study subjects prior to sample collection and confidentiality of results maintained. Finally, examples of three biorepositories of different scale (European Cancer Study, National Cancer Institute and School of Public Health Biorepository, University of California, Berkeley) are used to illustrate challenges faced by investigators and the ways to overcome them. New software and biorepository technologies are being developed by many companies that will help to bring biological banking to a new level required by molecular epidemiology of the 21st centurymiology of the 21st century

  20. Molecular epidemiology biomarkers--sample collection and processing considerations.

    Science.gov (United States)

    Holland, Nina T; Pfleger, Laura; Berger, Eileen; Ho, Alan; Bastaki, Maria

    2005-08-01

    Biomarker studies require processing and storage of numerous biological samples with the goals of obtaining a large amount of information and minimizing future research costs. An efficient study design includes provisions for processing of the original samples, such as cryopreservation, DNA isolation, and preparation of specimens for exposure assessment. Use of standard, two-dimensional and nanobarcodes and customized electronic databases assure efficient management of large sample collections and tracking results of data analyses. Standard operating procedures and quality control plans help to protect sample quality and to assure validity of the biomarker data. Specific state, federal and international regulations are in place regarding research with human samples, governing areas including custody, safety of handling, and transport of human samples. Appropriate informed consent must be obtained from the study subjects prior to sample collection and confidentiality of results maintained. Finally, examples of three biorepositories of different scale (European Cancer Study, National Cancer Institute and School of Public Health Biorepository, University of California, Berkeley) are used to illustrate challenges faced by investigators and the ways to overcome them. New software and biorepository technologies are being developed by many companies that will help to bring biological banking to a new level required by molecular epidemiology of the 21st century. PMID:15967217

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

    Energy Technology Data Exchange (ETDEWEB)

    de Almeida, Valmor F [ORNL; Hay, Benjamin [ORNL; DePaoli, David W [ORNL

    2009-10-01

    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.

  2. 1979 bibliography of atomic and molecular processes. [Bibliography

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-08-01

    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.

  3. 1978 bibliography of atomic and molecular processes. [Bibliography

    Energy Technology Data Exchange (ETDEWEB)

    1980-03-01

    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.

  4. Advances Towards Synthetic Machines at the Molecular and Nanoscale Level

    OpenAIRE

    Kristina Konstas; Langford, Steven J.; Latter, Melissa J.

    2010-01-01

    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 s...

  5. Information processing at single neuron level

    OpenAIRE

    Vidybida, A. K.

    2007-01-01

    Based on numerical simulation of Hodgkin and Huxley type neuron stimulated from many synaptic inputs, an abstract concept of signal processing in individual neuron is proposed. In the concept proposed, neuron performs binding of synaptic inputs into a single output event, based on the degree of temporal coherence between the inputs. Inhibition serves as controlling factor of this type of binding.

  6. 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

  7. 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

  8. Melatonin combats molecular terrorism at the mitochondrial level.

    Science.gov (United States)

    Reiter, Russel J; Paredes, Sergio D; Korkmaz, Ahmet; Jou, Mei-Jie; Tan, Dun-Xian

    2008-09-01

    The intracellular environmental is a hostile one. Free radicals and related oxygen and nitrogen-based oxidizing agents persistently pulverize and damage molecules in the vicinity of where they are formed. The mitochondria especially are subjected to frequent and abundant oxidative abuse. The carnage that is left in the wake of these oxygen and nitrogen-related reactants is referred to as oxidative damage or oxidative stress. When mitochondrial electron transport complex inhibitors are used, e.g., rotenone, 1-methyl-1-phenyl-1,2,3,6-tetrahydropyridine, 3-nitropropionic acid or cyanide, pandemonium breaks loose within mitochondria as electron leakage leads to the generation of massive amounts of free radicals and related toxicants. The resulting oxidative stress initiates a series of events that leads to cellular apoptosis. To alleviate mitochondrial destruction and the associated cellular implosion, the cell has at its disposal a variety of free radical scavengers and antioxidants. Among these are melatonin and its metabolites. While melatonin stimulates several antioxidative enzymes it, as well as its metabolites (cyclic 3-hydroxymelatonin, N(1)-acetyl-N(2)-formyl-5-methoxykynuramine and N(1)-acetyl-5-methoxykynuramine), likewise effectively neutralize free radicals. The resulting cascade of reactions greatly magnifies melatonin's efficacy in reducing oxidative stress and apoptosis even in the presence of mitochondrial electron transport inhibitors. The actions of melatonin at the mitochondrial level are a consequence of melatonin and/or any of its metabolites. Thus, the molecular terrorism meted out by reactive oxygen and nitrogen species is held in check by melatonin and its derivatives. PMID:21218104

  9. Advances Towards Synthetic Machines at the Molecular and Nanoscale Level

    Directory of Open Access Journals (Sweden)

    Kristina Konstas

    2010-06-01

    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.

  10. Manipulating the conduction process of a molecular resonant tunneling diode

    International Nuclear Information System (INIS)

    In this work we propose two methods to manipulate the conduction process in a molecular resonant tunneling diode. In the first proposal we make use of the fact that by twisting the molecule along the long axis, we can generate a nonlinear coupling between the conduction electrons and the phonons. In the second proposal, we allow a light of appropriate frequency to pump the electrons from the ground state to the first excited state. This mechanism generates an additional current across the molecular resonant tunneling diode. (author)

  11. High-level waste processing and disposal

    International Nuclear Information System (INIS)

    Without reprocessing, spent LWR fuel itself is generally considered an acceptable waste form. With reprocessing, borosilicate glass canisters, have now gained general acceptance for waste immobilization. The current first choice for disposal is emplacement in an engineered structure in a mined cavern at a depth of 500-1000 meters. A variety of rock types are being investigated including basalt, clay, granite, salt, shale, and volcanic tuff. This paper gives specific coverage to the national high level waste disposal plans for France, the Federal Republic of Germany, Japan and the United States. The French nuclear program assumes prompt reprocessing of its spent fuels, and France has already constructed the AVM. Two larger borosilicate glass plants are planned for a new French reprocessing plant at La Hague. France plans to hold the glass canisters in near-surface storage for a forty to sixty year cooling period and then to place them into a mined repository. The FRG and Japan also plan reprocessing for their LWR fuels. Both are currently having some fuel reprocessed by France, but both are also planning reprocessing plants which will include waste vitrification facilities. West Germany is now constructing the PAMELA Plant at Mol, Belgium to vitrify high level reprocessing wastes at the shutdown Eurochemic Plant. Japan is now operating a vitrification mockup test facility and plans a pilot plant facility at the Tokai reprocessing plant by 1990. Both countries have active geologic repository programs. The United State program assumes little LWR fuel reprocessing and is thus primarily aimed at direct disposal of spent fuel into mined repositories. However, the US have two borosilicate glass plants under construction to vitrify existing reprocessing wastes

  12. Processing of high-level radioactive waste

    International Nuclear Information System (INIS)

    US research and development directed at solidifying both commercial and defense HLW has reached an advanced stage, and production facilities are being designed, constructed and operated. Defense HLW has been calcined and stored in granular form at the Idaho Falls National Laboratory since 1963. Three pilot-scale demonstration programs to solidify HLW have been conducted at the Pacific Northwest Laboratory with radioactive HLW. The Defense Waste Processing Facility is under construction at the Savannah River Laboratory, South Carolina; it will solidify the defense HLW at that site. Similar facilities are planned for the Hanford, Washington, and Idaho Falls, Idaho, sites to treat the HLW from defense programs. The Department of Energy is conducting a demonstration HLW solidification program at the West Valley, New York, site to prepare the HLW stored in onsite tanks for geologic disposal. After briefly describing liquid HLW storage, this paper discusses vitrification technology and the projects that will utilize the technology to solidify HLW at several locations

  13. Theoretical analysis of dynamic processes for interacting molecular motors

    International Nuclear Information System (INIS)

    Biological transport is supported by the collective dynamics of enzymatic molecules that are called motor proteins or molecular motors. Experiments suggest that motor proteins interact locally via short-range potentials. We investigate the fundamental role of these interactions by carrying out an analysis of a new class of totally asymmetric exclusion processes, in which interactions are accounted for in a thermodynamically consistent fashion. This allows us to explicitly connect microscopic features of motor proteins with their collective dynamic properties. A theoretical analysis that combines various mean-field calculations and computer simulations suggests that the dynamic properties of molecular motors strongly depend on the interactions, and that the correlations are stronger for interacting motor proteins. Surprisingly, it is found that there is an optimal strength of interactions (weak repulsion) that leads to a maximal particle flux. It is also argued that molecular motor transport is more sensitive to attractive interactions. Applications of these results for kinesin motor proteins are discussed. (paper)

  14. 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.

  15. Semiclassical theory of electronically nonadiabatic transitions in molecular collision processes

    International Nuclear Information System (INIS)

    An introductory account of the semiclassical theory of the S-matrix for molecular collision processes is presented, with special emphasis on electronically nonadiabatic transitions. This theory is based on the incorporation of classical mechanics with quantum superposition, and in practice makes use of the analytic continuation of classical mechanics into the complex space or time domain. After a brief discussion of the relevant concepts of molecular scattering theory and related dynamical models, the formalism is developed and illustrated with simple examples - collinear collision of the A + BC type. The theory is then extended to include the effects of laser-induced nonadiabatic transitions. The lecture concludes with a discussion of two bound continuum processes - collisional ionization and collision-induced emission - also amenable to the same general semiclassical treatment. (orig.)

  16. Mesoscopic Properties of Molecular Folding and Aggregation Processes

    OpenAIRE

    Bachmann, Michael; Janke, Wolfhard

    2009-01-01

    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 ...

  17. Molecular-level Design of Heterogeneous Chiral Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  18. PFOS induced precocious hatching of Oryzias melastigma--from molecular level to individual level.

    Science.gov (United States)

    Wu, Xinlong; Huang, Qiansheng; Fang, Chao; Ye, Ting; Qiu, Ling; Dong, Sijun

    2012-05-01

    Perfluorooctane sulfonate (PFOS) showed a risk of causing adverse effects including hatching of animals. However, there are no systematical studies about the effects of PFOS on fish embryo hatching. In this study, a precocious hatching was detected in Oryzias melastigma embryos upon PFOS exposure. The average hatching time was shortened and the hatching rate increased after PFOS exposure. The subsequent survival rate decreased significantly in the larvae hatching from the PFOS-treated embryos compared to the control. The influence occurred in a PFOS concentration-dependent manner. To further elucidate the inner molecular change, full length cDNAs of hatching enzymes HCE and LCE were first cloned in O. melastigma by degenerate RT-PCR and RACE. PFOS elicited a transcriptional response of both HCE and LCE. The expressions of both genes were significantly up-regulated earlier in the PFOS-treated group than in the control group. The activity of hatching enzyme also significantly increased upon exposure. In all, our results showed that exposure to PFOS could induce the hatching enzyme both at transcriptional and enzymatic activity level and further lead to the precocious hatching of O. melastigma embryos, which induced the decrease of the subsequent larvae survival. PMID:22273185

  19. Understanding hydrodynamics in the cell at the molecular level

    Science.gov (United States)

    Bai, Xiaoyu; Wolynes, Peter

    2015-03-01

    Cellular collective motion is a result of complex coupling of nonequilibrium mechano-chemical events in the cytoskeleton, of which the underlying physics is far from completely understood. In an attempt to study the cytoskeletal dynamics, we develop analytical theories based on a coarse-grained model, Cat's Cradle. Our current work highlights how the activated events due to energy-consuming molecular motors are coupled by hydrodynamic interaction and therefore reveals the modified cytoskeletal dynamics. Within our framework, we were able to find the stability limit of the uniformly flowing phase, which is consistent with the predictions from the well-studied continuum models. In the model we accounted for the effect of shear-stretching forces on the extended structure of molecular motors. The resulting influenced stochastic properties of motor power strokes provide us with further insights into the nonequilibrium aspects of cellular dynamics.

  20. Dissociative processes in electron-molecular ion collisions

    Science.gov (United States)

    Djuric, Nada; Dunn, Gordon H.

    1998-10-01

    There is renewed interest in dissociation of molecular ions, primarily due to needs for modeling plasma generators for etching and deposition and for modeling edge plasmas for fusion reactors. At the same time, there are improvements in experimental techniques; e.g. use of heavy-ion storage rings has opened possibilities in dissociation studies of vibrationally relaxed molecular ions. At electron energies below the dissociation energy (D_e) of a molecular ion, the most importanat process is dissociative recombination (DR). Once the energy is above D_e, dissociative excitation (DE) is allowed, and at even higher energies dissociative ionization (DI) is energetically possible. In JILA we set up an apparatus wherein light fragment ions from DE of heteronuclear molecular ions are detected. In the heavy-ion storage ring at Stockholm (CRYRING) detection of neutral fragments was used for DE and DR studies. We will discuss the techniques and give examples of DE and DI obtainet at JILA and CRYRING [1,2,3]. Work supported in part by the Office of Fusion Energy of the U. S. DOE under Contract No. DE-A105-86ER53237 with NIST and in part by the Swedish Natural Science Research Council. 1. N. Djuric et al., Phys. Rev. A 56, 2887 (1997). 2. J. Semaniak et al., Ap. J. 498, 886 (1998). 3. J. R. Peterson et al., J. Chem. Phys. 108, 1978 (1998)

  1. Biotin Sensing at the Molecular Level1–3

    OpenAIRE

    Beckett, Dorothy

    2009-01-01

    Biotin influences transcription in organisms from bacteria to humans. The enzyme, biotin protein ligase, which catalyzes post-transcriptional biotin addition to biotin-dependent carboxylases, plays a central roll in transmitting the demand for biotin to gene expression. The molecular mechanism of this communication in bacteria is well understood and involves competing protein:protein interactions. Biochemical measurements indicate that this competition is kinetically controlled. In humans, th...

  2. A Complex Approach for Unravelling Musaceae Phylogeny at Molecular Level.

    Czech Academy of Sciences Publication Activity Database

    N?mcová, Pavla; H?ibová, Eva; Valárik, Miroslav; Doležel, Jaroslav

    2011-01-01

    Ro?. 897, SEP 14 (2011), s. 139-142. ISSN 0567-7572. [INTERNATIONAL ISHS-PROMUSA SYMPOSIUM ON GLOBAL PERSPECTIVES ON ASIAN CHALLENGES. Guangzhou, 14.08.2009-16.08.2009] R&D Projects: GA AV ?R IAA600380703 Institutional support: RVO:61389030 Keywords : DArT * low-copy genes * molecular phylogenetics Subject RIV: EF - Botanics http://www.actahort.org/books/897/897_14.htm

  3. Evidence for systems-level molecular mechanisms of tumorigenesis

    OpenAIRE

    Capellá Gabriel; Gómez Laia; Valls Joan; Montaner David; Al-Shahrour Fátima; Huerta-Cepas Jaime; Hernández Pilar; Dopazo Joaquín; Pujana Miguel

    2007-01-01

    Abstract Background Cancer arises from the consecutive acquisition of genetic alterations. Increasing evidence suggests that as a consequence of these alterations, molecular interactions are reprogrammed in the context of highly connected and regulated cellular networks. Coordinated reprogramming would allow the cell to acquire the capabilities for malignant growth. Results Here, we determine the coordinated function of cancer gene products (i.e., proteins encoded by differentially expressed ...

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

    OpenAIRE

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

    2002-01-01

    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.

  5. Levels of processing: the evolution of a framework

    Scientific Electronic Library Online (English)

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

    2011-12-01

    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 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.

  6. Molecular sieve sensors for selective detection at the nanogram level

    International Nuclear Information System (INIS)

    Zeolites have long been known for their molecular sieving properties based upon crystalline pore structures of molecular dimensions. The authors explore strategies to introduce molecular sieving functions into inorganic thin films and membranes which are of current interest for sensor coatings and gas-phase separations. The zeolite films offer high thermal stability (> 770 K) and chemical resistance. Surface acoustic wave devices can be operated as highly sensitive piezoelectric balances that respond to small fractions of single-crystal monolayer adsorption via frequency changes of an oscillator circuit. Since the response is nonselective, a number of organic and organometallic coatings on SAW devices have previously been explored to impart chemical selectivity. The SAW device (97 MHz, detection limit ca. 100 pg/cm2) used in the present study to measure selective adsorption of organic vapors (0.1% of saturation in nitrogen flow, 295 K) consists of a single-crystal quartz substrate with interdigital transducers which was coated with zeolite-silica thin films and mounted in a test chamber with gas inlet and outlet

  7. Molecular and Supramolecular Information Processing From Molecular Switches to Unconventional Computing

    CERN Document Server

    Katz, Evgeny

    2012-01-01

    Edited by a renowned and much cited chemist, this book covers the whole span of molecular computers that are based on non-biological systems. The contributions by all the major scientists in the field provide an excellent overview of the latest developments in this rapidly expanding area. A must-have for all researchers working on this very hot topic. Perfectly complements Biomolecular Information Processing, also by Prof. Katz, and available as a two-volume set.

  8. Space Based Multi-level Process Flow and Logistics Analysis

    Directory of Open Access Journals (Sweden)

    Zhou Qiu-Zhong

    2013-01-01

    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.

  9. 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

  10. Application of statistical process control to qualitative molecular diagnostic assays

    LENUS (Irish Health Repository)

    O'Brien, Cathal P.

    2014-11-01

    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.

  11. Entendendo o Processo Molecular da Tumorigênese / Understanding the Molecular Process of Tumorigenesis

    Scientific Electronic Library Online (English)

    Laura Sterian, Ward.

    2002-08-01

    Full Text Available Nos últimos 25 anos, o reconhecimento dos mecanismos genético-moleculares implicados na gênese e na progressão do câncer tem permitido obter novos métodos de diagnóstico e de acompanhamento, redirecionando de forma drástica a terapêutica do paciente com neoplasia. Alguns marcadores moleculares já es [...] tão sendo utilizados na rotina e deverão prover testes sensíveis e específicos para o diagnóstico precoce, estadiamento e acompanhamento do paciente com câncer. As características moleculares de cada tumor deverão permitir predição do seu comportamento, ajudando a delinear estratégias terapêuticas mais efetivas. Apresentamos de forma didática os principais mecanismos controladores do ciclo celular e do crescimento, definindo a importância de oncogenes erroneamente ativados e de genes supressores tumorais perdidos ou não-funcionantes, dos genes envolvidos na programação e manutenção da vida celular e de outros genes que atuam no processo de tumorigênese. Os mecanismos de progressão tumoral, invasão e metastatização à distância são revistos enfatizando-se a aplicação prática do conhecimento a respeito de tais mecanismos. Lembramos o papel da instabilidade genética e dos fenômenos epigenéticos na definição fenotípica do câncer, sugerindo as aplicações da genética molecular na terapia gênica do câncer. Abstract in english Over the past 25 years, knowledge of the genetic-molecular mechanisms involved in the genesis and progression of cancer have helped to obtain new diagnostic and follow up methods that have drastically redirected the therapeutics used in patients with neoplasia. Some molecular markers are already bei [...] ng routinely used and should provide sensitive and specific tests for early diagnosis, staging and follow up of cancer patients. The molecular characteristics of each tumor should help in predicting its behavior and outlining more effective therapeutic strategies. We have used a didactic manner of presenting the main mechanisms that control the growth and cellular cycle, defined the importance of erroneously activated oncogenes and tumor suppressor genes that are lost or non-functioning, genes involved in programming and maintaining cell life as well as other genes that participate in the tumorigenic process. The mechanisms of tumor progression, invasion and metastasis are reviewed placing an emphasis on the practical application of the knowledge related to these mechanisms. The role of genetic instability and epigenetic changes in the definition of cancer phenotype have been underscored, suggesting the application of molecular genetics in the gene therapy of cancer.

  12. Molecular dynamics simulation of processing using AFM pin tool

    Science.gov (United States)

    Yan, Y. D.; Sun, T.; Dong, S.; Luo, X. C.; Liang, Y. C.

    2006-08-01

    A three-dimensional molecular dynamics (MD) model is utilized to investigate the effect of tool geometry on the deformation process of the workpiece and the nature of deformation process at the atomic-scale. Results show that different states exist between the atomic force microscope (AFM) pin tool and the workpiece surface, i.e. the non-wear state, the ploughing state, the state in which ploughing is dominant and the state in which cutting plays a key role. A relationship between the deformation process of the workpiece and the potential energy variation is presented. The potential energy variation of atoms in different deformed regions in the workpiece such as plastically deformed region, elastically deformed region and the mixed deformation region is different. The features of variations of potential energy are discussed.

  13. High-Level Waste System Process Interface Description

    Energy Technology Data Exchange (ETDEWEB)

    d' Entremont, P.D.

    1999-01-14

    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.

  14. 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

  15. Space Based Multi-level Process Flow and Logistics Analysis

    OpenAIRE

    Zhou Qiu-Zhong; Ning Guo-Liang; Xu Wan-Hong

    2013-01-01

    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 mu...

  16. Exploring the Impact of and Perceptions about Interactive, Self-Explaining Environments in Molecular- Level Animations

    Directory of Open Access Journals (Sweden)

    David A. Falvo

    2011-01-01

    Full Text Available This mixed-method study investigates the effects of interactivity in animations of a molecular-level process and explores perceptions aboutthe animated learning tool used. Treatments were based on principlesof cognitive psychology designed to study the main effects of treatment and spatial ability and their interaction. Results with students (n=189 showed that science majors scored higher than non-science majors in retention measures (i.e., structure and function but not in transfer. Significant main effects were found for treatment in function questions and spatial ability in structure questions. There was a significant interaction between treatment and spatial ability in structure questions. Additionally, in this study participants believed the key and the motion of ions and molecules were the most helpful parts of the animation. This study shows that students perceive the animations as being supportive of their learning, suggesting that animations do have a role in scienceclassrooms.

  17. Decision Driven Scenario Planning for Process-Level Interventions

    Science.gov (United States)

    Chemarck, Thomas J.; Payne, Tiffani D.

    2005-01-01

    This article builds on previous work that classified types of scenario planning as effective or relevant for particular situations, by adding consideration for levels within the organization. In addition, the argument is built for using a particular form of scenarios to anticipate or explore process level problems and outcomes. The problem of…

  18. Application to processing system using intra-molecular BRET

    Science.gov (United States)

    Otsuji, Tomomi; Okuda-Ashitaka, Emiko; Kojima, Satoshi; Akiyama, Hidehumi; Ito, Seiji; Ohmiya, Yoshihiro

    2003-07-01

    Luciferases are used as the reporter gene for promoter activity, whereas a green fluorescent protein (GFP) is used as marker for cellular function and localization. Recently, bioluminescence resonance energy transfer (BRET) between luciferase and YFP is used for analysis of inter-molecular reaction such as ligand-receptor in the living cells. The neuropeptides nocistatin (NST) and nociceptin/orphanin FQ (Noc/OFQ) are derived from the same precursor protein, while NST exhibits antagonism against Noc/OFQ-actions. In this study, we attempt an intra-molecular BRET system for monitoring dynamic biological process of the production of NST and Noc/OFQ in the living cells. At first, we constructed a fusion protein (Rluc-GFP) covalently linking luciferase (Renilla luciferase; Rluc) to Aequorea GFP as an intra-molecular BRET partner. Furthermore, we inserted constructs of mouse NST and Noc/OFQ (Rluc-m-GFP) or bovine NST and Noc/OFQ (Rluc-b-GFP) containing a proteolytic cleavage motif (Lys-Arg) within Rluc-GFP. When these constructions were transfected into Cos7 cells, all fusion proteins had luciferase activity and specific fluorescence. Luminescence spectra of Rluc-GFP, Rluc-m-GFP and Rluc-b-GFP fusion proteins with DeepBlueC as a substrate showed two peaks centered at 400 nm and 510 nm, whereas Rluc showed one peak centered at 400 nm. These results indicate that the proteolytic cleavage motif inserted fusion proteins between luciferase and GFP are available for intra-molecular BRET systems at first step.

  19. Exploring the impact of and perceptions about interactive, self-explaining environments in molecular-level animations

    OpenAIRE

    Falvo, David A.; Urban, Michael J.; Suits, Jerry P.

    2011-01-01

    This mixed-method study investigates the effects of interactivity in animations of a molecular-level process and explores perceptions about the animated learning tool used. Treatments were based on principles of cognitive psychology designed to study the main effects of treatment and spatial ability and their interaction. Results with students (n=189) showed that science majors scored higher than non-science majors in retention measures (i.e., structure and function) but not in transfer. Sign...

  20. 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

  1. Molecular evidence for species-level distinctions in clouded leopards.

    Science.gov (United States)

    Buckley-Beason, Valerie A; Johnson, Warren E; Nash, Willliam G; Stanyon, Roscoe; Menninger, Joan C; Driscoll, Carlos A; Howard, JoGayle; Bush, Mitch; Page, John E; Roelke, Melody E; Stone, Gary; Martelli, Paolo P; Wen, Ci; Ling, Lin; Duraisingam, Ratna K; Lam, Phan V; O'Brien, Stephen J

    2006-12-01

    Among the 37 living species of Felidae, the clouded leopard (Neofelis nebulosa) is generally classified as a monotypic genus basal to the Panthera lineage of great cats. This secretive, mid-sized (16-23 kg) carnivore, now severely endangered, is traditionally subdivided into four southeast Asian subspecies (Figure 1A). We used molecular genetic methods to re-evaluate subspecies partitions and to quantify patterns of population genetic variation among 109 clouded leopards of known geographic origin (Figure 1A, Tables S1 ans S2 in the Supplemental Data available online). We found strong phylogeographic monophyly and large genetic distances between N. n. nebulosa (mainland) and N. n. diardi (Borneo; n = 3 individuals) with mtDNA (771 bp), nuclear DNA (3100 bp), and 51 microsatellite loci. Thirty-six fixed mitochondrial and nuclear nucleotide differences and 20 microsatellite loci with nonoverlapping allele-size ranges distinguished N. n. nebulosa from N. n. diardi. Along with fixed subspecies-specific chromosomal differences, this degree of differentiation is equivalent to, or greater than, comparable measures among five recognized Panthera species (lion, tiger, leopard, jaguar, and snow leopard). These distinctions increase the urgency of clouded leopard conservation efforts, and if affirmed by morphological analysis and wider sampling of N. n. diardi in Borneo and Sumatra, would support reclassification of N. n. diardi as a new species (Neofelis diardi). PMID:17141620

  2. Simulation of deacidification process by molecular distillation of deodorizer distillate

    Scientific Electronic Library Online (English)

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

    2008-12-01

    Full Text Available 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.

  3. Molecular-Level Monte Carlo Simulation at Fixed Entropy.

    Czech Academy of Sciences Publication Activity Database

    Lísal, Martin

    Bratislava : Slovak Society of Chemical Engineering, 2006 - (Štefuca, V.; Markoš, J.), s. 288 ISBN 80-227-2409-2. [International Conference of Slovak Society of Chemical Engineering /33./. Tatranské Matliare (SK), 22.05.2006-26.05.2006] Institutional research plan: CEZ:AV0Z40720504 Keywords : monte-carlo method * fluid system * expansion processes Subject RIV: CF - Physical ; Theoretical Chemistry

  4. Coalescence process of two cooper nanoparticles: molecular dynamics simulation

    International Nuclear Information System (INIS)

    Molecular Dynamics simulation, using an empirical potential EAM for the modeling of the atomic interaction, have been performed to study the coalescence process of two spherical Cu nanoparticles that contains equal number of atoms N = 736. The simulation is made with md step equal to 1.6 fs without applying periodic boundary conditions. The previously optimized nanoparticles has bounding energy -3.2805 eV/atom and melting temperature 989 K. The coalescence process with collision velocity of 400 and 800 m/s is analyzed at temperatures 300 and 600 K. The geometric and structural changes, that undergo particles during the collision process and sintering as well as the variation of number of atoms in the neck of the system are analyzed. It is observed that even at relatively low temperatures as 300 K nanoparticles are crowded together forming a single particle, but the final geometric form and the kinetic of the process is different at different temperatures and collision energies. The faceting surface of nanoparticles obeys the dynamics of the coalescence process. (author)

  5. Regulation of leaf hydraulics: from molecular to whole plant levels

    OpenAIRE

    Prado, Karine; Maurel, Christophe

    2013-01-01

    The water status of plant leaves is dependent on both stomatal regulation and water supply from the vasculature to inner tissues. The present review addresses the multiple physiological and mechanistic facets of the latter process. Inner leaf tissues contribute to at least a third of the whole resistance to water flow within the plant. Physiological studies indicated that leaf hydraulic conductance (Kleaf) is highly dependent on the anatomy, development and age of the leaf and can vary rapidl...

  6. Computing molecular fluctuations in biochemical reaction systems based on a mechanistic, statistical theory of irreversible processes.

    Science.gov (United States)

    Kulasiri, Don

    2011-01-01

    We discuss the quantification of molecular fluctuations in the biochemical reaction systems within the context of intracellular processes associated with gene expression. We take the molecular reactions pertaining to circadian rhythms to develop models of molecular fluctuations in this chapter. There are a significant number of studies on stochastic fluctuations in intracellular genetic regulatory networks based on single cell-level experiments. In order to understand the fluctuations associated with the gene expression in circadian rhythm networks, it is important to model the interactions of transcriptional factors with the E-boxes in the promoter regions of some of the genes. The pertinent aspects of a near-equilibrium theory that would integrate the thermodynamical and particle dynamic characteristics of intracellular molecular fluctuations would be discussed, and the theory is extended by using the theory of stochastic differential equations. We then model the fluctuations associated with the promoter regions using general mathematical settings. We implemented ubiquitous Gillespie's algorithms, which are used to simulate stochasticity in biochemical networks, for each of the motifs. Both the theory and the Gillespie's algorithms gave the same results in terms of the time evolution of means and variances of molecular numbers. As biochemical reactions occur far away from equilibrium-hence the use of the Gillespie algorithm-these results suggest that the near-equilibrium theory should be a good approximation for some of the biochemical reactions. PMID:21187228

  7. Kratzer potential for vibrational levels in molecular hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Hooydonk, Guido van [Ghent Univ., Faculty of Sciences (Belgium)

    2009-12-15

    The vibrational part of the dihydrogen Hamiltonian obeys a quantized Sommerfeld-Kratzer potential, which takes into account internal H{sub 2} symmetries. All constants {omega}{sub e}, k{sub e}, and r{sub e} needed for the H{sub 2} vibrational system derive from hydrogen mass. Ionic Kratzer bond theory gives covalent bond energy within 0.08% and all levels within 0.02%, which is 30 times better than with a Dunham oscillator and as accurate as early ab initio quantum mechanics. (orig.)

  8. 0-level Vacuum Packaging RT Process for MEMS Resonators

    CERN Document Server

    Abelé, N; Hibert, C; Casset, F; Ancey, P; Ionescu, A

    2008-01-01

    A new Room Temperature (RT) 0-level vacuum package is demonstrated in this work, using amorphous silicon (aSi) as sacrificial layer and SiO2 as structural layer. The process is compatible with most of MEMS resonators and Resonant Suspended-Gate MOSFET [1] fabrication processes. This paper presents a study on the influence of releasing hole dimensions on the releasing time and hole clogging. It discusses mass production compatibility in terms of packaging stress during back-end plastic injection process. The packaging is done at room temperature making it fully compatible with IC-processed wafers and avoiding any subsequent degradation of the active devices.

  9. Levels of processing and Eye Movements: A Stimulus driven approach

    DEFF Research Database (Denmark)

    Mulvey, Fiona Bríd

    2014-01-01

    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.

  10. Effect of Bread Making Process on Aflatoxin Level Changes

    Directory of Open Access Journals (Sweden)

    Jafar Milani

    2014-12-01

    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.

  11. Level sets and extrema of random processes and fields

    CERN Document Server

    Azais, Jean-Marc

    2009-01-01

    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...

  12. INTEGRATING CMMI MATURITY LEVEL-3 IN TRADITIONAL SOFTWARE DEVELOPMENT PROCESS

    OpenAIRE

    Reena Dadhich; Ujala Chauhan

    2012-01-01

    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...

  13. Cascading Activation Across Levels of Representation in Children's Lexical Processing

    OpenAIRE

    Snedeker, Jesse; Huang, Yi Ting

    2010-01-01

    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 measures of incremental activation of semantic representations during word recognition in children. Five-year-olds were instructed to select a target (log...

  14. Molecular Dynamics of Polymer Systems on Graphic Processing Units (GPUs)

    Science.gov (United States)

    Anderson, Joshua; Lorenz, Chris; Travesset, Alex

    2008-03-01

    Molecular dynamics (MD) is a powerful, but computationally intensive, simulation technique capable of modeling a wide range of systems in and out of thermodynamic equilibrium. Using traditional computers, simulations large enough to explore the phases of polymer systems require the use of expensive distributed memory clusters. Graphics Processing Units now offer an unprecedented amount of computing power for general purpose applications. They are inexpensive (500) and can be added to almost any standard desktop system. MD algorithms are adapted to execute on a single GPU, which is able to attain the same performance as 32 processor cores on a cluster. It is possible for a single system to host up to 4 GPUs, putting the power of a 128 processor core cluster on the desktop. This performance is illustrated in a variety of polymer systems such as low density micellar phases with cubic symmetry, high density lamellar and nanocomposite gyroid systems. GPUs offer unprecedented opportunities for the simulation of polymer systems.

  15. Graphics processing units accelerated semiclassical initial value representation molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Tamascelli, Dario; Dambrosio, Francesco Saverio [Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano (Italy); Conte, Riccardo [Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322 (United States); Ceotto, Michele, E-mail: michele.ceotto@unimi.it [Dipartimento di Chimica, Università degli Studi di Milano, via Golgi 19, 20133 Milano (Italy)

    2014-05-07

    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.

  16. Graphics processing units accelerated semiclassical initial value representation molecular dynamics

    International Nuclear Information System (INIS)

    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

  17. Molecular Surveillance of Viral Processes Using Silicon Nitride Membranes

    Directory of Open Access Journals (Sweden)

    Deborah F. Kelly

    2013-03-01

    Full Text Available Here we present new applications for silicon nitride (SiN membranes to evaluate biological processes. We determined that 50-nanometer thin films of SiN produced from silicon wafers were sufficiently durable to bind active rotavirus assemblies. A direct comparison of SiN microchips with conventional carbon support films indicated that SiN performs equivalent to the traditional substrate to prepare samples for Electron Microscopy (EM imaging. Likewise, SiN films coated with Ni-NTA affinity layers concentrated rotavirus particles similarly to affinity-coated carbon films. However, affinity-coated SiN membranes outperformed glow-discharged conventional carbon films 5-fold as indicated by the number of viral particles quantified in EM images. In addition, we were able to recapitulate viral uncoating and transcription mechanisms directed onto the microchip surfaces. EM images of these processes revealed the production of RNA transcripts emerging from active rotavirus complexes. These results were confirmed by the functional incorporation of radiolabeled nucleotides into the nascent RNA transcripts. Collectively, we demonstrate new uses for SiN membranes to perform molecular surveillance on life processes in real-time.

  18. Organization of Lipids in the Tear Film: A Molecular-Level View

    OpenAIRE

    Wizert, Alicja; Iskander, D. Robert; Cwiklik, Lukasz

    2014-01-01

    Biophysical properties of the tear film lipid layer are studied at the molecular level employing coarse grain molecular dynamics (MD) simulations with a realistic model of the human tear film. In this model, polar lipids are chosen to reflect the current knowledge on the lipidome of the tear film whereas typical Meibomian-origin lipids are included in the thick non-polar lipids subphase. Simulation conditions mimic those experienced by the real human tear film during blinks. Namely, thermodyn...

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

    Directory of Open Access Journals (Sweden)

    Shigemura Masahiko

    2012-07-01

    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.

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

    Science.gov (United States)

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

    2014-05-01

    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

  1. High-Level waste process and product data annotated bibliography

    International Nuclear Information System (INIS)

    The objective of this document is to provide information on available issued documents that will assist interested parties in finding available data on high-level waste and transuranic waste feed compositions, properties, behavior in candidate processing operations, and behavior on candidate product glasses made from those wastes. This initial compilation is only a partial list of available references

  2. Process Analysis and Level Measurement of Textbooks Use by Teachers

    Science.gov (United States)

    Kong, Fanzhe; Shi, Ningzhong

    2009-01-01

    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…

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

    DEFF Research Database (Denmark)

    Stadler, Robert; Jacobsen, Karsten Wedel

    2006-01-01

    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.

  4. Ab initio quantum mechanical/molecular mechanical simulation of electron transfer process: Fractional electron approach

    Science.gov (United States)

    Zeng, Xiancheng; Hu, Hao; Hu, Xiangqian; Cohen, Aron J.; Yang, Weitao

    2008-03-01

    Electron transfer (ET) reactions are one of the most important processes in chemistry and biology. Because of the quantum nature of the processes and the complicated roles of the solvent, theoretical study of ET processes is challenging. To simulate ET processes at the electronic level, we have developed an efficient density functional theory (DFT) quantum mechanical (QM)/molecular mechanical (MM) approach that uses the fractional number of electrons as the order parameter to calculate the redox free energy of ET reactions in solution. We applied this method to study the ET reactions of the aqueous metal complexes Fe(H2O)62+/3+ and Ru(H2O)62+/3+. The calculated oxidation potentials, 5.82 eV for Fe(II/III) and 5.14 eV for Ru(II/III), agree well with the experimental data, 5.50 and 4.96 eV, for iron and ruthenium, respectively. Furthermore, we have constructed the diabatic free energy surfaces from histogram analysis based on the molecular dynamics trajectories. The resulting reorganization energy and the diabatic activation energy also show good agreement with experimental data. Our calculations show that using the fractional number of electrons (FNE) as the order parameter in the thermodynamic integration process leads to efficient sampling and validate the ab initio QM/MM approach in the calculation of redox free energies.

  5. Molecular dynamics simulations of cluster fission and fusion processes

    DEFF Research Database (Denmark)

    Lyalin, Andrey G.; Obolensky, Oleg I.

    2004-01-01

    Results of molecular dynamics simulations of fission reactions Na_10^2+ --> Na_7^+ +Na_3^+ and Na_18^2+ --> 2Na_9^+ are presented. The dependence of the fission barriers on the isomer structure of the parent cluster is analyzed. It is demonstrated that the energy necessary for removing homothetic groups of atoms from the parent cluster is largely independent of the isomer form of the parent cluster. The importance of rearrangement of the cluster structure during the fission process is elucidated. This rearrangement may include transition to another isomer state of the parent cluster before actual separation of the daughter fragments begins and/or forming a "neck" between the separating fragments. A novel algorithm for modeling the cluster growth process is described. This approach is based on dynamic search for the most stable cluster isomers and allows one to find the optimized cluster geometries, as well as their essential formation mechanisms. Cluster growth paths for Lennard–Jones clusters have been investigated for cluster sizes of up to 150 atoms. All known global minima structures of the Lennard–Jones clusters are found.

  6. INTEGRATING CMMI MATURITY LEVEL-3 IN TRADITIONAL SOFTWARE DEVELOPMENT PROCESS

    Directory of Open Access Journals (Sweden)

    Reena Dadhich

    2012-02-01

    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.

  7. 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

  8. Effect of the bread-making process on zearalenone levels.

    Science.gov (United States)

    Heidari, Sara; Milani, Jafar; Nazari, Seyed Saman Seyed Jafar

    2014-01-01

    The effects of the bread-making process including fermentation with Saccharomyces cerevisiae and lactic acid bacteria (Lactobacillus casei, Lactobacillus rhamnosus, Lactobacillus acidophilus and Lactobacillus fermentum) and baking at 200°C on zearalenone (ZEA) levels were investigated. Standard solutions of ZEA were added to flour and then loaves of bread were prepared. Sourdough and three types of yeast including active dry yeast, instant dry yeast and compressed yeast were used for the fermentation of dough. ZEA levels in flour, dough and bread were determined by HPLC with fluorescence detection after extraction and clean-up on an immunoaffinity column. The highest reduction in levels of ZEA was found in the first fermentation (first proof), while the lowest reduction was observed in the baking stage. In addition, the results showed that compressed yeast had the maximum reduction potential on ZEA levels even at the baking stage. PMID:25291600

  9. Quantum information processing at the cellular level. Euclidean approach

    CERN Document Server

    Ogryzko, Vasily

    2009-01-01

    Application of quantum principles to living cells requires a new approximation of the full quantum mechanical description of intracellular dynamics. We discuss what principal elements any such good approximation should contain. As one such element, the notion of "Catalytic force" Cf is introduced. Cf is the effect of the molecular target of catalysis on the catalytic microenvironment that adjusts the microenvironment towards a state that facilitates the catalytic act. This phenomenon is experimentally testable and has an intriguing implication for biological organization and evolution, as it amounts to "optimization without natural selection of replicators". Unlike the statistical-mechanical approaches to self-organization, the Cf principle does not encounter the problem of "tradeoff between stability and complexity" at the level of individual cell. Physically, the Cf is considered as a harmonic-like force of reaction, which keeps the state of the cell close to the ground state, defined here as a state where ...

  10. Optimal degradation processes control by two-level policies

    Energy Technology Data Exchange (ETDEWEB)

    Kopnov, V.A

    1999-10-01

    Two-level control policies are applied to various types of Markov processes describing degrading parameters of system units. To estimate the system operation cost an expectation of losses per unit time is evaluated. It is assumed that the degradation process is observable, and a monitoring system can signal about future failures. Firstly, semi-Markov processes are considered. A death process is proposed for a unit subjected to corrosion. A Markov chain are used for the problem of fatigue crack growth. The control problem is studied mainly in a steady-state regime for units of multiple use when the cost function is performed as the ratio of expectations. The cost function as the expectation of losses per unit time for single units is also studied, and the majorizing property of this cost function is shown.

  11. 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

  12. Optimal degradation processes control by two-level policies

    International Nuclear Information System (INIS)

    Two-level control policies are applied to various types of Markov processes describing degrading parameters of system units. To estimate the system operation cost an expectation of losses per unit time is evaluated. It is assumed that the degradation process is observable, and a monitoring system can signal about future failures. Firstly, semi-Markov processes are considered. A death process is proposed for a unit subjected to corrosion. A Markov chain are used for the problem of fatigue crack growth. The control problem is studied mainly in a steady-state regime for units of multiple use when the cost function is performed as the ratio of expectations. The cost function as the expectation of losses per unit time for single units is also studied, and the majorizing property of this cost function is shown

  13. Commercial low level waste processing in a competitive market

    International Nuclear Information System (INIS)

    In most nations with active nuclear establishments, Low Level Radioactive Waste (LLW) is treated, packaged and disposed of by a single governmental organization or corporation that operates in a monopoly situation. In the US, LLW generated from utility and industry sources is processed at various commercial enterprises throughout the country and buried in commercially owned and operated LLW disposal facilities. These centralized waste processing or 'fixed base' companies provide their services in a competitive, free market environment. This competition has led to the development and use of effective technologies for waste volume reduction. The actual techniques used are chosen based on cost impact to company's financial performance rather than budget considerations

  14. 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

  15. High Level Loop Transformations for Systematic Signal Processing Embedded Applications

    OpenAIRE

    Glitia, Calin; Boulet, Pierre

    2008-01-01

    Array-OL specification model is a mixed graphical-textual language designed especially to model multidimensional intensive signal processing applications. Data and Task parallelism are specified directly in the model. High level transformations are defined on this model, allowing the refactoring of an application and furthermore providing directions for optimization. The resemblances with the wide-known and used loop transformations lead us to try taking concepts and results from this domain ...

  16. Mixing Processes in High-Level Waste Tanks - Final Report

    International Nuclear Information System (INIS)

    The mixing processes in large, complex enclosures using one-dimensional differential equations, with transport in free and wall jets is modeled using standard integral techniques. With this goal in mind, we have constructed a simple, computationally efficient numerical tool, the Berkeley Mechanistic Mixing Model, which can be used to predict the transient evolution of fuel and oxygen concentrations in DOE high-level waste tanks following loss of ventilation, and validate the model against a series of experiments

  17. Molecular processes from the AGB to the PN stage

    CERN Document Server

    Garcia-Hernandez, D A

    2011-01-01

    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.

  18. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    D.L. McGregor

    2000-12-20

    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.

  20. [Study on the spectroscopic data and vibrational levels of the ground SiH+ molecular ion].

    Science.gov (United States)

    Zhao, Jun; Zeng, Hui

    2014-12-01

    The ground electronic state and the reasonable dissociation limit of SiH+ molecular ion have been correctly determined based on group theory and atomic and molecular reaction statics. The energy, equilibrium geometry and harmonic frequency of the ground electronic state of SiH+ molecular ion have been calculated using the method QCISD(T)/cc-pVQZ. The whole potential curves for the ground electronic state is further scanned using the above method, the potential energy functions and relevant spectroscopic constants of this state are then first obtained by least square fitting to the Murrell-Sorbie function (n=9) and the modified Murrell-Sorbie+c6 function, respectively. The present results showed that the calculated results based on the Murrell-Sorbie function (n=9) are in better agreement with the experimental values, with the relative errors between spectroscopic constants and the experimental values being 0.13%, 3.07%, 0.38%, 5.25% and 0.52% respectively. With the potential obtained at the QCISD(T)/cc-pVQZ level of theory, the total of 27 vibrational states are predicted when J=0 by numerically solving the radial Schrodinger equation of nuclear motion. The complete vibrational levels, inertial rotation and six centrifugal distortion constants are obtained for the ground electronic state of SiH+ molecular ion for the first time. Calculation results in the present work may provide theoretical supports for the further study of SiH+ molecular ion. PMID:25881406

  1. 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)

  2. Process Design Concepts for Stabilization of High Level Waste Calcine

    Energy Technology Data Exchange (ETDEWEB)

    T. R. Thomas; A. K. Herbst

    2005-06-01

    The current baseline assumption is that packaging ¡§as is¡¨ and direct disposal of high level waste (HLW) calcine in a Monitored Geologic Repository will be allowed. The fall back position is to develop a stabilized waste form for the HLW calcine, that will meet repository waste acceptance criteria currently in place, in case regulatory initiatives are unsuccessful. A decision between direct disposal or a stabilization alternative is anticipated by June 2006. The purposes of this Engineering Design File (EDF) are to provide a pre-conceptual design on three low temperature processes under development for stabilization of high level waste calcine (i.e., the grout, hydroceramic grout, and iron phosphate ceramic processes) and to support a down selection among the three candidates. The key assumptions for the pre-conceptual design assessment are that a) a waste treatment plant would operate over eight years for 200 days a year, b) a design processing rate of 3.67 m3/day or 4670 kg/day of HLW calcine would be needed, and c) the performance of waste form would remove the HLW calcine from the hazardous waste category, and d) the waste form loadings would range from about 21-25 wt% calcine. The conclusions of this EDF study are that: (a) To date, the grout formulation appears to be the best candidate stabilizer among the three being tested for HLW calcine and appears to be the easiest to mix, pour, and cure. (b) Only minor differences would exist between the process steps of the grout and hydroceramic grout stabilization processes. If temperature control of the mixer at about 80„aC is required, it would add a major level of complexity to the iron phosphate stabilization process. (c) It is too early in the development program to determine which stabilizer will produce the minimum amount of stabilized waste form for the entire HLW inventory, but the volume is assumed to be within the range of 12,250 to 14,470 m3. (d) The stacked vessel height of the hot process vessels in the hydroceramic grout process (i.e., 21 m) appears to be about the same as that estimated by the Direct Cementitious Waste Process in 1998, for which a conceptual design was developed. Some of the conceptual design efforts in the 1998 study may be applicable to the stabilizer processes addressed in this EDF. (e) The gamma radiation fields near the process vessels handling HLW calcine would vary from a range of about 300-350 R/hr at a distance of 2.5 cm from the side of the vessels to a range of about 50-170 R/hr at a distance of 100 cm from the side of the vessels. The calculations were made for combined calcine, which was defined as the total HLW calcine inventory uniformly mixed. (f) The gamma radiation fields near the stabilized waste in canisters would range from about 25-170 R/hr at 2.5 cm from the side of the canister and 5-35 R/hr at 100 cm from the side of the canister, depending on the which bin set was the source of calcine.

  3. Cascading activation from lexical processing to letter-level processing in written word production.

    Science.gov (United States)

    Buchwald, Adam; Falconer, Carolyn

    2014-01-01

    Descriptions of language production have identified processes involved in producing language and the presence and type of interaction among those processes. In the case of spoken language production, consensus has emerged that there is interaction among lexical selection processes and phoneme-level processing. This issue has received less attention in written language production. In this paper, we present a novel analysis of the writing-to-dictation performance of an individual with acquired dysgraphia revealing cascading activation from lexical processing to letter-level processing. The individual produced frequent lexical-semantic errors (e.g., chipmunk???SQUIRREL) as well as letter errors (e.g., inhibit???INBHITI) and had a profile consistent with impairment affecting both lexical processing and letter-level processing. The presence of cascading activation is suggested by lower letter accuracy on words that are more weakly activated during lexical selection than on those that are more strongly activated. We operationalize weakly activated lexemes as those lexemes that are produced as lexical-semantic errors (e.g., lethal in deadly???LETAHL) compared to strongly activated lexemes where the intended target word (e.g., lethal) is the lexeme selected for production. PMID:25163539

  4. Melt-processing method for low level radioactive wastes

    International Nuclear Information System (INIS)

    When melting low level radioactive solid wastes for processing them, it is effective for stably capturing Cs as one of volatile nuclides in a molten material to increase concentration of SiO2 or the concentration of Al2O3 among ingredients of slug layers in the molten material. On the other hand, coal ash (including fly ash) contains a great amount of SiO2 and Al2O3. In the present invention, the coal ash is added when melting the low level radioactive wastes. In this case, the coal ash is taken into the slug layers of the molten materials to increase not only the SiO2 concentration but also Al2O3 concentration in the slug layers and lower the basicity. Accordingly, volatility of Cs is suppressed even if the melting point exceeds far beyond the boiling point of Cs, and Cs is captured effectively in the molten material. (T.M.)

  5. Method for pre-processing of level crossing image

    Directory of Open Access Journals (Sweden)

    Roman RYBALKA

    2015-03-01

    Full Text Available Actuality of problem in the improvement of transport safety at level crossings (LC is caused by increasing the number of vehicles and reducing discipline of vehicle drivers. One of ways for solution of this problem is associated with using the video surveillance systems for monitoring danger area of level crossing. In such systems due to the limited bandwidth of data channel usually the image compression techniques are used. In this paper the pre-processing method for compression of images is presented. Proposed method accounts unequal subjective informational content of different LC image regions (using fuzzy logic and wavelet transform. Comparison of this method with plain set partitioning in hierarchical trees (SPIHT technique showed that proposed method allows obtaining better result at image compression in terms of reconstruction quality and compression ratio.

  6. [Level investigation on coptidis rhizoma processing methods and product specifications].

    Science.gov (United States)

    Huang, He; Liu, Xin; Huang, Lu-Qi; Yang, Yan-Fang; Wu, He-Zhen

    2014-08-01

    The existing processing methods, commercial specification and grades, and the marketing of Coptidis Rhizoma were systematical researched, referring to ancient, modern and contemporary medical literatures with the combination of our fieldwork on main origins of Coptidis Rhizoma and some herbs markets. Results showed that Coptidis Rhizoma processing methods mainly included sun-dried method and baked method anciently. For now, the processing methods become various, including thin paper-covering under the sun drying, direct drying, oven drying and microflame-fry drying. In the literatures, the main chemical constituent berberine was determined of its content to analyze the processing methods, finding that the sun drying and baked drying affect the berberine content, so the temperature must be controlled when drying. The thin paper-covering drying method is so cumbersome for large quantities of medicinal herbs and in wind conditions that it has been eliminated. Eventually, direct drying, oven drying and microflame-fry drying are chosen to the large-scale socialized production for their convenient and simple operation, making up the current main processing methods. Coptidis Rhizoma products have 3 specifications of Weilian, Yalian, Yunlian, of each specification there are 2 levels, but in fact the market of Weilian commodities overtakes the Yunlian, which only sold in parts of Yunnan, and the no-sale Yalian. The mainstream commercial Weilian are often sold in general way, gradeless and uniformly-priced. There are regional differences of the processing methods on Coptidis Rhizoma, which needs unified research and development of relevant standard operating procedures to ensure the quality of medicine, urgently. Coptidis Rhizoma product specifications and the intrinsic quality-grade correlation need to be further improved, which could provide a more reliable standard for quality at competitive prices, and it is recommended that "medicinal commercial specification and grade standard" content be increased into the Herbs part of Chinese Pharmacopoeia. PMID:25509292

  7. 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

  8. An algebraic approach for simultaneous solution of process and molecular design problems

    Scientific Electronic Library Online (English)

    S., Bommareddy; N. G., Chemmangattuvalappil; C. C., Solvason; M. R., Eden.

    2010-09-01

    Full Text Available The property integration framework has allowed for simultaneous representation of processes and products from a properties perspective and thereby established a link between molecular and process design problems. The simultaneous approach involves solving two reverse problems. The first reverse prob [...] lem identifies the property targets corresponding to the desired process performance. The second reverse problem is the reverse of a property prediction problem, which identifies the molecular structures that match the targets identified in the first problem. Group Contribution Methods (GCM) are used to form molecular property operators that will be used to track properties. Earlier contributions in this area have worked to include higher order estimation of GCM for solving the molecular design problem. In this work, the accuracy of the property prediction is further enhanced by improving the techniques to enumerate higher order groups. Incorporation of these higher order enumeration techniques increases the efficiency of property prediction and thus the application range of the group contribution methods in molecular design problems. Successful tracking of properties is the key in applying the reverse problem formulation for integrated process and product design problems. An algebraic technique has been developed for solving process and molecular design problems simultaneously. Since both process and molecular property operators target the same optimum process performance, the set of inequality expressions can be solved simultaneously to identify the molecules that meet the desired process performance. Since this approach is based on an algebraic algorithm, any number of properties can be tracked simultaneously.

  9. Radiation levels in the mineral processing industry in Malaysia

    International Nuclear Information System (INIS)

    As part of the continuing project of Radiometric Survey of the Malaysian environment, a preliminary reconnaissance study of the gamma-ray field in some amang processing plants in Malaysia has just been completed. Amang is the mixture of minerals remaining after the extraction of tin ore from the heavy mineral concentrate which is obtained in alluvial tin mining. Thorium and/or uranium are associated with three of the minerals in amang, namely monazite, xenotime and zircon. About 500 measurements were made, initially with a beta-gamma G.M. survey meter and subsequently with a scintillation counter. Sites surveyed within the amang processing plants and some typical readings of radiation levels in mR/hr are as follows: Office rooms (0.02-0.05); laboratories (0.1-0.8); mineral dressing machinery (0.2-2.0); temporary stock - piles of mineral concentrates within the plant sheds (0.2-10.0) and separately housed stockpiles of mineral separates (0.5-14.0). Preliminary results indicate that the radiation levels at some of the surveyed sites in the plants can be significant in terms of personnel exposure. Detailed measurements under more accurately controlled conditions and evaluation of actual personnel exposures are in progress. (author)

  10. EOS MLS Level 1B Data Processing Software. Version 3

    Science.gov (United States)

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

    2011-01-01

    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.

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

    OpenAIRE

    Tycko, Robert

    2006-01-01

    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...

  12. Synergistic effect of fluorination on molecular energy level modulation in highly efficient photovoltaic polymers.

    Science.gov (United States)

    Zhang, Maojie; Guo, Xia; Zhang, Shaoqing; Hou, Jianhui

    2014-02-01

    The synergistic effect of fluorination on molecular energy level modulation is realized by introducing fluorine atoms onto both the donor and the acceptor moieties in a D-A polymer, and as a result, the polymer solar cell device based on the trifluorinated polymer, PBT-3F, shows a high efficiency of 8.6%, under illumination of AM 1.5G, 100 mW cm(-) (2) . PMID:24259399

  13. Discovering multi-level structures in bio-molecular data through the Bernstein inequality

    OpenAIRE

    Valentini Giorgio; Bertoni Alberto

    2008-01-01

    Abstract Background The unsupervised discovery of structures (i.e. clusterings) underlying data is a central issue in several branches of bioinformatics. Methods based on the concept of stability have been recently proposed to assess the reliability of a clustering procedure and to estimate the “optimal” number of clusters in bio-molecular data. A major problem with stability-based methods is the detection of multi-level structures (e.g. hierarchical functional classes of genes), and the ...

  14. Process technology for vitrification of high level waste

    International Nuclear Information System (INIS)

    Vitrification as a process for the management of high level liquid waste (HLLW) has been accepted worldwide including India. Vitrification process based on borosilicate matrices has evolved in India right from employing metallic melters in early eighties to currently deployed ceramic melters. Induction of cold crucible melters are also on the anvil for vitrification of HLLW from advanced fuel cycles. The vitrification technology is a challenge in view of remote operation under molten corrosive glass environment and intense radiations. Successful operation of the vitrification plants and induction of new generation melters is a vital step for our successful implementation of reprocessing and recycle programme. Right from melter feeding, processing, product draining, canister welding and product withdrawal call for a robust technology with remote operations and high operator skills. High corrosion potential of molten glass on material of construction of the melter throws ample challenge to engineer the entire system. Mastering the technology of vitrification is a challenge and the experiences gained from the design and operations of the existing vitrification plants are a big achievement in itself

  15. Directional solvent for membrane-free water desalination-A molecular level study

    OpenAIRE

    Luo, Tengfei; Bajpayee, Anurag; Chen, Gang

    2011-01-01

    Development of desalination technologies has been identified as vital to fulfilling future water demand. In this paper, we use molecular simulation to demonstrate that decanoic acid can dissolve water but reject salt, and itself is insoluble in water. We have recently demonstrated that the directional properties of decanoic acid together with the temperature dependence of water solubility in decanoic acid can be utilized to design a desalination process which extracts water molecules, using t...

  16. Design and synthesis of molecular donors for solution-processed high-efficiency organic solar cells.

    Science.gov (United States)

    Coughlin, Jessica E; Henson, Zachary B; Welch, Gregory C; Bazan, Guillermo C

    2014-01-21

    Organic semiconductors incorporated into solar cells using a bulk heterojunction (BHJ) construction show promise as a cleaner answer to increasing energy needs throughout the world. Organic solar cells based on the BHJ architecture have steadily increased in their device performance over the past two decades, with power conversion efficiencies reaching 10%. Much of this success has come with conjugated polymer/fullerene combinations, where optimized polymer design strategies, synthetic protocols, device fabrication procedures, and characterization methods have provided significant advancements in the technology. More recently, chemists have been paying particular attention to well-defined molecular donor systems due to their ease of functionalization, amenability to standard organic purification and characterization methods, and reduced batch-to-batch variability compared to polymer counterparts. There are several critical properties for efficient small molecule donors. First, broad optical absorption needs to extend towards the near-IR region to achieve spectral overlap with the solar spectrum. Second, the low lying highest occupied molecular orbital (HOMO) energy levels need to be between -5.2 and -5.5 eV to ensure acceptable device open circuit voltages. Third, the structures need to be relatively planar to ensure close intermolecular contacts and high charge carrier mobilities. And last, the small molecule donors need to be sufficiently soluble in organic solvents (?10 mg/mL) to facilitate solution deposition of thin films of appropriate uniformity and thickness. Ideally, these molecules should be constructed from cost-effective, sustainable building blocks using established, high yielding reactions in as few steps as possible. The structures should also be easy to functionalize to maximize tunability for desired properties. In this Account, we present a chronological description of our thought process and design strategies used in the development of highly efficient molecular donors that achieve power conversion efficiencies greater than 7%. The molecules are based on a modular D(1)-A-D(2)-A-D(1) architecture, where A is an asymmetric electron deficient heterocycle, which allowed us to quickly access a library of compounds and develop structure-property-performance relationships. Modifications to the D1 and D2 units enable spectral coverage throughout the entire visible region and control of HOMO energy levels, while adjustments to the pendant alkyl substituents dictate molecular solubility, thermal transition temperatures, and solid-state organizational tendencies. Additionally, we discuss regiochemical considerations that highlight how individual atom placements can significantly influence molecular and subsequently device characteristics. Our results demonstrate the utility of this architecture for generating promising materials to be integrated into organic photovoltaic devices, call attention to areas for improvement, and provide guiding principles to sustain the steady increases necessary to move this technology forward. PMID:23984626

  17. Phase behaviour of macromolecular liquid crystalline materials. Computational studies at the molecular level

    International Nuclear Information System (INIS)

    Molecular simulations provide an increasingly useful insight into the static and dynamic characteristics of materials. In this thesis molecular simulations of macro-molecular liquid crystalline materials are reported. The first liquid crystalline material that has been investigated is a side chain liquid crystal polymer (SCLCP). In this study semi-atomistic molecular dynamics simulations have been conducted at a range of temperatures and an aligning potential has been applied to mimic the effect of a magnetic field. In cooling the SCLCP from an isotropic melt, microphase separation was observed yielding a domain structure. The application of a magnetic field to this structure aligns the domains producing a stable smectic mesophase. This is the first study in which mesophases have been observed using an off-lattice model of a SCLCP. The second material that has been investigated is a dendrimer with terminal mesogenic functionalization. Here, a multi-scale approach has been taken with Monte Carlo studies of a single dendrimer molecule in the gas phase at the atomistic level, semi-atomistic molecular dynamics of a single molecule in liquid crystalline solvents and a coarse-grained molecular dynamics study of the dendrimer in the bulk. The coarse-grained model has been developed and parameterized using the results of the atomistic and semi-atomistic work. The single molecule studies showed that the liquid crystalline dendrimer was able to change its structure by conformat able to change its structure by conformational changes in the flexible chains that link the mesogenic groups to the core. Structural change was seen under the application of a mean field ordering potential in the gas phase, and in the presence of liquid crystalline solvents. No liquid crystalline phases were observed for the bulk phase studies of the coarse-grained model. However, when the length of the mesogenic units was increased there was some evidence for microphase separation in these systems. (author)

  18. Signatures of molecular single-particle states by level crossings in heavy ion collisions

    OpenAIRE

    Park, Jae Y.; Greiner, Walter; Scheid, Werner

    2006-01-01

    In heavy ion collisions, the molecular single-particle motion may cause specific structures in the energy dependence of the cross sections which arise by the promotion of nucleons at level crossings according to the Landau-Zener excitation mechanism. In order to examine this effect in asymmetric heavy ion collisions, we have calculated level diagrams of the two-center shell model for the target projectile combinations 13C + 16O and 12C + 17O and analyzed with respect to inelastic excitation a...

  19. Heat impact caused molecular level changes in solid and dissolved soil organic matter

    Science.gov (United States)

    Hofmann, Diana; Steffen, Bernhard; Eckhardt, Kai-Uwe; Leinweber, Peter

    2015-04-01

    The ubiquitous abundance of pyrolysed, highly aromatic organic matter, called "Black Carbon" (BC), in all environmental compartments became increasingly important in different fields of research beyond intensive investigated atmospheric aerosol due to climatic relevance. Its predominant high resistance to abiotic and biotic degradation resulted in turnover times from less than a century to several millennia. This recalcitrance led to the enrichment of BC in soils, accounting for 1-6% (European forest soils) to 60% (Chernozems) of total soil organic matter (SOM). Hence, soil BC acts an important sink in the global carbon cycle. In contrast, consequences for the nitrogen cycle up to date are rather inconsistently discussed. Soil related dissolved organic matter (DOM) is a major controlling factor in soil formation, an important pathway of organic matter transport and one of the largest active carbon reservoirs on earth, if considering oceans and other bodies of water. The aim of this study was to evaluate the effects of artificially simulated wildfire by thermal treatment on the molecular composition of water extractable soil organic matter (DOM). Soils from two outdoor lysimeters with different management history were investigated. Soil samples, non-heated and heated up to 350°C were analyzed for elemental composition (carbon, nitrogen and sulfur) and for bulk molecular composition by Pyrolysis-Field Ionization Mass Spectrometry (Py-FIMS) and synchrotron-based X-ray Absorption Near-Edge Spectroscopy (XANES) at the C- and N K-edges. DOM-samples obtained by hot water extraction, desalting and concentration by solid phase extraction were subsequently analyzed by flow injection analysis in a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer (FTICR-MS), equipped with an ESI source and a 7 T supra-conducting magnet (LTQ-FT Ultra, ThermoFisher Scientific). This technique is the key technique for the analysis of complex samples due to its outstanding mass resolution (used 400.000 at m/z 400 Da) and mass accuracy (? 1 ppm), simultaneously providing molecular level details of thousands of compounds. The characteristics and differences of the FTICR-MS spectra with as many as ten or more peaks at each nominal mass are discussed: heated samples showed considerable higher intensities of even numbered peaks. An in-house developed, automated post processing was used for further exploitation of the data with the aim of an unambiguous assignment of as many peaks as possible. Obtained mass lists were transformed for sorting and preparation/ interpretation of graphics like Kendrick and van Krevelen plots. The heat-treated solid samples show decreasing C/N ratios and the formation cyclic and N-heterocyclic compounds in good agreement among the various methods (Py-FIMS and C- and N-XANES). Detailed insight into the hot-water extracts by FTICR-MS showed clear qualitative as well as quantitative changes in the number and the intensity of nitrogen and nitrogen + sulfur containing compounds, respectively, which generally became enriched under soil heating. This demonstrates for the first time, that not only the bulk SOM is affected in structure by heat impact but also the more mobile DOM. We assume, that heat impact volatilizes and oxidizes parts of the organic substances is as expected but another part of the substances incorporates (further) nitrogen atom(s) similar to the generation of new compounds under the conditions of plasma etching in nitrogen atmosphere. This would explain to some extent, why soils are e.g. after fire clearing of vegetation are highly fertile for a short period (better plant acceptable compounds) but become more infertile in the long run, especially under tropical conditions with frequently heavy rain that would lead to an increased leaching of compounds with higher polarity.

  20. Tectonic processes modelling for high-level radioactive waste disposal

    International Nuclear Information System (INIS)

    The possibility of using deep geological formations to dispose of high-level radioactive waste (HLW) is a subject raising heated debate among scientists. In Russia, the idea of constructing HLW repository in the Niznekansky granitoid massif (NKM) in Krasnoyarsk area is widely discussed. To solve this problem we are elaborating a technology associated with time – space stability prediction of the geological environment, which is subject to geodynamic processes evolutionary effects. It is based on the prediction of isolation properties stability in a structural tectonic block of the Earth’s crust for a given time. The danger is in the possibility that the selected structural block may be broken by new tectonic faults or movements on a passive fault may be activated and thus underground water may penetrate to HLW containers

  1. Atmospheric processes on ice nanoparticles in molecular beams.

    Czech Academy of Sciences Publication Activity Database

    Fárník, Michal; Poterya, Viktoriya

    2014-01-01

    Ro?. 2, ?. 2014 (2014), s. 4. ISSN 2296-2646 R&D Projects: GA ?R GA203/09/0422; GA ?R GAP208/11/0161 Institutional support: RVO:61388955 Keywords : molecular beams * photodissociation * water clusters Subject RIV: BL - Plasma and Gas Discharge Physics

  2. Impact of Altimeter Data Processing on Sea Level Studies

    Directory of Open Access Journals (Sweden)

    Clara Lázaro

    2006-03-01

    Full Text Available This study addresses the impact of satellite altimetry data processing on sea levelstudies at regional scale, with emphasis on the influence of various geophysical correctionsand satellite orbit on the structure of the derived interannual signal and sea level trend. Thework focuses on the analysis of TOPEX data for a period of over twelve years, for threeregions in the North Atlantic: Tropical (0o≤φ≤25o, Sub-Tropical (25o≤φ≤50o and Sub-Arctic (50o≤φ≤65o. For this analysis corrected sea level anomalies with respect to a meansea surface model have been derived from the GDR-Ms provided by AVISO by applyingvarious state-of-the-art models for the geophysical corrections. Results show that sea leveltrend determined from TOPEX altimetry is dependent on the adopted models for the majorgeophysical corrections. The main effects come from the sea state bias (SSB, and from theapplication or not of the inverse barometer (IB correction. After an appropriate modellingof the TOPEX A/B bias, the two analysed SSB models induce small variations in sea leveltrend, from 0.0 to 0.2 mm/yr, with a small latitude dependence. The difference in sea leveltrend determined by a non IB-corrected series and an IB-corrected one has a strong regionaldependence with large differences in the shape of the interannual signals and in the derivedlinear trends. The use of two different drift models for the TOPEX Microwave Radiometer(TMR has a small but non negligible effect on the North Atlantic sea level trend of about0.1 mm/yr. The interannual signals of sea level time series derived with the NASA and theCNES orbits respectively, show a small departure in the middle of the series, which has noimpact on the derived sea level trend. These results strike the need for a continuousimprovement in the modelling of the various effects that influence the altimetermeasurement.

  3. Decontamination processes for low level radioactive waste metal objects

    International Nuclear Information System (INIS)

    Disposal and safe storage of contaminated nuclear waste is a problem of international scope. Although the greatest volume of such waste is concentrated in the USA and former Soviet Union, Western Europe and Japan have contaminated nuclear waste requiring attention. Japan's radioactive nuclear waste is principally generated at nuclear power plants since it has no nuclear weapons production. However, their waste reduction, storage and disposal problems may be comparable to that of the USA on an inhabited area basis when consideration is given to population density where Japan's population, half that of the USA, lives in an area slightly smaller than that of California's. If everyone's backyard was in California, the USA might have insoluble radioactive waste reduction, storage and disposal problems. Viewing Japan's contaminated nuclear waste as a national problem requiring solutions, as well as an economic opportunity, Morikawa began research and development for decontaminating low level radioactive nuclear waste seven years ago. As engineers and manufacturers of special machinery for many years Morikawa brings special electro/mechanical/pneumatic Skills and knowledge to solving these unique problems. Genden Engineering Services and Construction Company (GESC), an affiliate of Japan Atomic Power Company, recently joined with Morikawa in this R ampersand D effort to decontaminate low level radioactive nuclear waste (LLW) and to substantially reduce the volume of such nucubstantially reduce the volume of such nuclear waste requiring long term storage. This paper will present equipment with both mechanical and chemical processes developed over these several years by Morikawa and most recently in cooperation with GESC

  4. Predicting the residual aluminum level in water treatment process

    Directory of Open Access Journals (Sweden)

    J. Tomperi

    2012-06-01

    Full Text Available In water treatment processes, aluminum salts are widely used as coagulation chemical. High dose of aluminum has been proved to be at least a minor health risk and some evidence points out that aluminum could increase the risk of Alzheimer's disease thus it is important to minimize the amount of residual aluminum in drinking water and water used at food industry. In this study, the data of a water treatment plant (WTP was analyzed and the residual aluminum in drinking water was predicted using Multiple Linear Regression (MLR and Artificial Neural Network (ANN models. The purpose was to find out which variables affect the amount of residual aluminum and create simple and reliable prediction models which can be used in an early warning system (EWS. Accuracy of ANN and MLR models were compared. The new nonlinear scaling method based on generalized norms and skewness was used to scale all measurement variables to range [?2...+2] before data-analysis and modeling. The effect of data pre-processing was studied by comparing prediction results to ones achieved in an earlier study. Results showed that it is possible to predict the baseline level of residual aluminum in drinking water with a simple model. Variables that affected the most the amount of residual aluminum were among others: raw water temperature, raw water KMnO4 and PAC / KMnO4-ratio. The accuracies of MLR and ANN models were found to be almost equal. Study also showed that data pre-processing affects to the final prediction result.

  5. Sequential Remediation Processes for a Low Level Pesticide Wastewater

    Directory of Open Access Journals (Sweden)

    Abdel E. Ghaly

    2012-02-01

    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.

  6. Work of adhesion between mucin macromolecule and calcium-alginate gels on molecular level.

    Science.gov (United States)

    Popeski-Dimovski, Riste

    2015-06-01

    The bioadhesion of biopolymers to mucus layers is of great interest for the development of drug delivery systems. Herein we use AFM force measurements to evaluate the interaction on molecular level between a mucin macromolecule attached to an AFM tip and a calcium-alginate gel layer. The total work of adhesion is measured from the AFM force curves depending on different parameters: time of contact, G/M ratio of the alginate, and crosslink ratio of the gel. The total work of adhesion is found to be in the range of 1×10(-19) to 6×10(-18)J. The results show that the work of adhesion increases with the time of contact but it is independent from the molecular mass of the alginate, the G/M ratio of the alginate and crosslink ratio of the gel. PMID:25843845

  7. Molecular-level understanding of the adsorption mechanism of a graphite-binding peptide at the water/graphite interface.

    Science.gov (United States)

    Penna, M J; Mijajlovic, M; Tamerler, C; Biggs, M J

    2015-07-14

    The association of proteins and peptides with inorganic material has vast technological potential. An understanding of the adsorption of peptides at liquid/solid interfaces on a molecular-level is fundamental to fully realising this potential. Combining our prior work along with the statistical analysis of 100+ molecular dynamics simulations of adsorption of an experimentally identified graphite binding peptide, GrBP5, at the water/graphite interface has been used here to propose a model for the adsorption of a peptide at a liquid/solid interface. This bottom-up model splits the adsorption process into three reversible phases: biased diffusion, anchoring and lockdown. Statistical analysis highlighted the distinct roles played by regions of the peptide studied here throughout the adsorption process: the hydrophobic domain plays a significant role in the biased diffusion and anchoring phases suggesting that the initial impetus for association between the peptide and the interface may be hydrophobic in origin; aromatic residues dominate the interaction between the peptide and the surface in the adsorbed state and the polar region in the middle of the peptide affords a high conformational flexibility allowing strongly interacting residues to maximise favourable interactions with the surface. Reversible adsorption was observed here, unlike in our prior work focused on a more strongly interacting surface. However, this reversibility is unlikely to be seen once the peptide-surface interaction exceeds 10 kcal mol(-1). PMID:25920450

  8. Analysis of process-monitoring data bases for low-level-waste processing

    International Nuclear Information System (INIS)

    West Valley Nuclear Services (WVNS) Company developed the integrated radwaste treatment system (IRTS) to remotely process and store existing PUREX (plutonium uranium reduction extraction) wastes in a stabilized form. The IRTS utilizes four major subsystems in its processing of the waste. Initial mobilization of the waste and removal of cesium is performed by the supernatant treatment system. The decontaminated supernate is then volume reduced by the liquid waste treatment system. Stabilization of the waste is accomplished in the cement solidification system (CSS), where it is combined with cement and various other additives and processed into 71-gal drums. The processed drums are then transported to the drum cell, where they are remotely stacked and stored. To verify compliance of the final product, WVNS quality assurance personnel developed a comprehensive program for monitoring all low-level-waste production activities. An integral portion of this program validates, verifies, and analyzes the process data acquisition systems (DASs). Results obtained in initial operations have found various anomalies inherent in the gathering of process records. Errors denoted were attributed to the DASs, operation, and the process control plan. The changes made continue to make marked improvements in the accuracy and completeness of the CSS and drum cell documentation

  9. 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)

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

    Science.gov (United States)

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

    2009-05-01

    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.

  11. Cross sections for hydrogen muonic atomic processes in two-level approximation of the adiabatic framework

    International Nuclear Information System (INIS)

    The phase-shifts and cross sections have been calculated in a broad collision energy range (0.001 ? ? ? 50 eV) for the elastic scattering, isotopic exchange and spin-flip hydrogen muonic atomic processes. The so-called ''simple approach'' to the three-body problem with the Coulomb interaction in the adiabatic two-level approximation has been applied. The comparison of the obtained values with available results of the multichannel approximation shows that the accuracy of our calculations is about 10%. The presented set of the phases and cross sections together with corrections for the electron screening and molecular structure enables one to investigate kinetics of the muon-catalyzed fusion in any mixtures of hydrogen isotopes

  12. MOLOCH computer code for molecular-dynamics simulation of processes in condensed matter

    Directory of Open Access Journals (Sweden)

    Derbenev I.V.

    2011-01-01

    Full Text Available Theoretical and experimental investigation into properties of condensed matter is one of the mainstreams in RFNC-VNIITF scientific activity. The method of molecular dynamics (MD is an innovative method of theoretical materials science. Modern supercomputers allow the direct simulation of collective effects in multibillion atom sample, making it possible to model physical processes on the atomistic level, including material response to dynamic load, radiation damage, influence of defects and alloying additions upon material mechanical properties, or aging of actinides. During past ten years, the computer code MOLOCH has been developed at RFNC-VNIITF. It is a parallel code suitable for massive parallel computing. Modern programming techniques were used to make the code almost 100% efficient. Practically all instruments required for modelling were implemented in the code: a potential builder for different materials, simulation of physical processes in arbitrary 3D geometry, and calculated data processing. A set of tests was developed to analyse algorithms efficiency. It can be used to compare codes with different MD implementation between each other.

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

    International Nuclear Information System (INIS)

    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 infoe 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.

  14. Tank farm processing of high-level waste for the Defense Waste Processing Facility

    International Nuclear Information System (INIS)

    The high-level radioactive waste that has accumulated at the Savannah River Plant is stored in large, underground steel tanks. Programs to remove the waste from the storage tanks and immobilize the radioactivity in borosilicate glass in the Defense Waste Processing Facility (DWPF) are currently in the construction phase. Much of the processing of the waste prior to vitrification is accomplished in the waste storage areas (tank farms). Tank farm processing includes resuspension and washing of the insoluble (sludge) waste, dissolution and decontamination of soluble (salt) waste, and waste transfer between the tanks and operations areas. The overall program for handling the waste in the tank farms, the research program that supports it, and the major concerns with implementing the program are described

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

    DEFF Research Database (Denmark)

    Engelund, Emil Tang

    2011-01-01

    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.

  16. Computational methods to study the structure and dynamics of biomolecules and biomolecular processes from bioinformatics to molecular quantum mechanics

    CERN Document Server

    2014-01-01

    Since the second half of the 20th century machine computations have played a critical role in science and engineering. Computer-based techniques have become especially important in molecular biology, since they often represent the only viable way to gain insights into the behavior of a biological system as a whole. The complexity of biological systems, which usually needs to be analyzed on different time- and size-scales and with different levels of accuracy, requires the application of different approaches, ranging from comparative analysis of sequences and structural databases, to the analysis of networks of interdependence between cell components and processes, through coarse-grained modeling to atomically detailed simulations, and finally to molecular quantum mechanics. This book provides a comprehensive overview of modern computer-based techniques for computing the structure, properties and dynamics of biomolecules and biomolecular processes. The twenty-two chapters, written by scientists from all over t...

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

    Science.gov (United States)

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

    2014-05-01

    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.

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

    International Nuclear Information System (INIS)

    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

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

    DEFF Research Database (Denmark)

    Thygesen, Kristian Sommer; Rubio, Angel

    2009-01-01

    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.

  20. Deformation processes in polycrystalline Zr by molecular dynamics simulations

    Science.gov (United States)

    Lu, Zizhe; Noordhoek, Mark J.; Chernatynskiy, Aleksandr; Sinnott, Susan B.; Phillpot, Simon R.

    2015-07-01

    Molecular dynamics simulation is used to characterize the deformation behavior of polycrystalline Zr. The predictions of two different potentials, an embedded atom method potential and a charge optimized many body potential are compared. The experimentally observed prismatic dislocations, pyramidal dislocations and twinning behaviors are produced in the simulations of [ 1 1 2 bar 0 ] and [0 0 0 1] textured structures and in fully 3D structure simulations. The relationship between the generalized stacking fault energy and the mechanical properties is discussed. In particular we find that the different shapes of the generalized stacking-fault energy curve for the two different interatomic descriptions of Zr have a significant effect on the deformation mechanisms. The deformation behavior of Zr is compared with analogous simulations of deformation of polycrystalline Mg.

  1. The reorganization energy of electron transfer in nonpolar solvents: Molecular level treatment of the solvent

    International Nuclear Information System (INIS)

    The intermolecular electron transfer in a solute pair consisting of pyrene and dimethylaniline is investigated in a nonpolar solvent, n-hexane. The earlier elaborated approach [M. Tachiya, J. Phys Chem. 97, 5911 (1993)] is used; this method provides a physically relevant background for separating inertial and inertialess polarization responses for both nonpolarizable and polarizable molecular level simulations. The molecular-dynamics technique was implemented for obtaining the equilibrium ensemble of solvent configurations. The nonpolar solvent, n-hexane, was treated in terms of OPLS-AA parametrization. Solute Lennard-Jones parameters were taken from the same parametrization. Solute charge distributions of the initial and final states were determined using ab initio level [HF/6-31G(d,p)] quantum-chemical calculations. Configuration analysis was performed explicitly taking into account the anisotropic polarizability of n-hexane. It is shown that the Gaussian law well describes calculated distribution functions of the solvent coordinate, therefore, the rate constant of the ET reaction can be characterized by the reorganization energy. Evaluated values of the reorganization energies are in a range of 0.03-0.11 eV and significant contribution (more then 40% of magnitude) comes from anisotropic polarizability. Investigation of the reorganization energy ? dependence on the solute pair separation distance d revealed unexpected behavior. The dependence has a very sharp peak or. The dependence has a very sharp peak at the distance d=7 A where solvent molecules are able to penetrate into the intermediate space between the solute pair. The reason for such behavior is clarified. This new effect has a purely molecular origin and cannot be described within conventional continuum solvent models

  2. Reconstructing the free-energy landscape associated to molecular motors processivity

    CERN Document Server

    Alamilla, J Lopez

    2012-01-01

    We propose a biochemical model providing the kinetic and energetic descriptions of the processivity dynamics of kinesin and dinein molecular motors. Our approach is a modified version of a well known model describing kinesin dynamics and considers the presence of a competitive inhibition reaction by ADP. We first reconstruct a continuous free-energy landscape of the cycle catalyst process that allows us to calculate the number of steps given by a single molecular motor. Then, we calculate an analytical expression associated to the translational velocity and the stopping time of the molecular motor in terms of time and ATP concentration. An energetic interpretation of motor processivity is discussed in quantitative form by using experimental data. We also predict a time duration of collective processes that agrees with experimental reports.

  3. Proceedings of the DAE-BRNS theme meeting on application of molecular modeling in separation processes

    International Nuclear Information System (INIS)

    This conference deals with molecular modelling which encompasses all theoretical methods and computational techniques to model or mimic the behaviour of molecules. This is used as important tool to design and simulate extractants for solvent extraction processes, stationary phases for chromatographic separation processes, polymeric network for membranes and highly selective precipitants. Papers relevant to INIS are indexed separately

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

    Science.gov (United States)

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

    2011-03-01

    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 parameters of the renal biotin reabsorption process. We addressed these issues using rats and transgenic mice carrying the human SLC5A6 (P1P2) 5'-regulatory region as an in vivo model systems of alcohol exposure, and cultured human renal proximal tubular epithelial HK-2 cells chronically exposed to alcohol as an in vitro model of alcohol exposure. The [(3)H]biotin uptake results showed that chronic ethanol feeding in rats leads to a significant inhibition in carrier-mediated biotin transport across both renal brush border and basolateral membrane domains. This inhibition was associated with a marked reduction in the level of expression of SMVT protein, mRNA, and heterogenous nuclear RNA (hnRNA). Furthermore, studies with transgenic mice carrying the SLC5A6 5'-regulatory region showed that chronic alcohol feeding leads to a significant decrease in promoter activity. Studies with HK-2 cells chronically exposed to alcohol again showed a marked reduction in carrier-mediated biotin uptake, which was associated with a significant reduction in promoter activity of the human SLC5A6 5'-regulatory region. These findings demonstrate for the first time that chronic ethanol feeding inhibits renal biotin transport and that this effect is, at least in part, being exerted at the transcriptional level. PMID:21209005

  5. 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)

  6. Recent progress in atomic and molecular processes in plasma

    International Nuclear Information System (INIS)

    In the recent works, atomic processes in Debye plasmas are investigated by a series of methods including the classical, semi-classical and quantum-mechanical ones. It's found that due to the plasma screening of the interactions both the binding energies and the number of bound states are reduced, while the radial extension of the wave functions become broader. Taking into account these plasma screening effects on the atomic structure and interactions, we have studied the photo processes, electron-impact processes and heavy particle collisions in a wide range of plasma screening conditions. Our work demonstrates that the screening effects are very important in Debye plasmas, which should be taken into account in the modeling and diagnostics of these plasmas. (author)

  7. The Henry Ford Production System: LEAN Process Redesign Improves Service in the Molecular Diagnostic Laboratory

    Science.gov (United States)

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

    2009-01-01

    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 production. Our goal was to complete greater than 90% of the molecular tests in less than 3 days. The project required cooperation from different laboratory disciplines as well as individuals outside of the laboratory. The redesigned processes involved defining and standardizing the protocols and approaching blood and tissue specimens as analytes for molecular testing. The LEAN process resulted in fewer steps, approaching the ideal of a one-piece flow for specimens through collection/retrieval, transport, and different aspects of the testing process. The outcome of introducing the LEAN process has been a 44% reduction in molecular test turnaround time for tissue specimens, from an average of 2.7 to 1.5 days. In addition, extending LEAN work principles to the clinician suppliers has resulted in a markedly increased number of properly collected and shipped blood specimens (from 50 to 87%). These continuous quality improvements were accomplished by empowered workers in a blame-free environment and are now being sustained with minimal management involvement. PMID:19661386

  8. A study on melting process of perylene using molecular dynamics simulation

    OpenAIRE

    Peyvasteh, M.; Setayeshi, S.; Vaez Zadeh, M.; Afzal Zadeh, R.

    2014-01-01

    Melting process of perylene is investigated using molecular dynamics simulation. Some of thermodynamic properties such as potential energy and transition order parameter are calculated as a function of temperature in the range of 500 K-600 K. These calculations are performed by two different methods in NPT and NVT ensembles. The selected interaction potential is Re-squared and the simulations are performed by LAMMPS (a classic molecular dynamics code). The results show that NPT ensemble is mo...

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

    DEFF Research Database (Denmark)

    García Lastra, Juan Maria; Rostgaard, Carsten

    2009-01-01

    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.

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

    DEFF Research Database (Denmark)

    Jin, Chengjun; Thygesen, Kristian Sommer

    2014-01-01

    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.

  11. A New Approach To Teaching Signal Processing At Undergraduate Level

    OpenAIRE

    Boashash, Boualem; Sridharan, S.; Chandran, V

    1996-01-01

    This paper describes the design and implementation of a unique undergraduate program in signal processing at the Queensland University of Technology (QUT). The criteria that influenced the choice of the subjects and the laboratories developed to support them are presented. A recently established Signal Processing Research Centre (SPRC) has played an important role in the development of the signal processing teaching program. The SPRC also provides training opportuni...

  12. Understanding the Relative Contributions of Lower-Level Word Processes, Higher-Level Processes, and Working Memory to Reading Comprehension Performance in Proficient Adult Readers

    Science.gov (United States)

    Hannon, Brenda

    2012-01-01

    Although a considerable amount of evidence has been amassed regarding the contributions of lower-level word processes, higher-level processes, and working memory to reading comprehension, little is known about the relationships among these sources of individual differences or their relative contributions to reading comprehension performance. This…

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

    CERN Document Server

    Erdmann, Thorsten; Schwarz, Ulrich S

    2013-01-01

    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...

  14. 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

  15. Molecular processes in a high temperature shock layer

    Science.gov (United States)

    Guberman, Steven L.

    1987-01-01

    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.

  16. 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

  17. Memory Scanning, Introversion-Extraversion, and Levels of Processing.

    Science.gov (United States)

    Eysenck, Michael W.; Eysenck, M. Christine

    1979-01-01

    Investigated was the hypothesis that high arousal increases processing of physical characteristics and reduces processing of semantic characteristics. While introverts and extroverts had equivalent scanning rates for physical features, introverts were significantly slower in searching for semantic features of category membership, indicating…

  18. Impact of molecular clustering inside nanopores on desorption processes.

    Science.gov (United States)

    Tsotsalas, Manuel; Hejcik, Pavel; Sumida, Kenji; Kalay, Ziya; Furukawa, Shuhei; Kitagawa, Susumu

    2013-03-27

    Understanding the sorption kinetics of nanoporous systems is crucial for the development and design of novel porous materials for practical applications. Here, using a porous coordination polymer/quartz crystal microbalance (PCP/QCM) hybrid device, we investigate the desorption of various vapor molecules featuring different degrees of intermolecular (hydrogen bonding) or molecule-framework interactions. Our findings reveal that strong intermolecular interactions lead to the desorption process proceeding via an unprecedented metastable state, wherein the guest molecules are clustered within the pores, causing the desorption rate to be temporarily slowed. The results demonstrate the considerable impact of the chemical nature of an adsorbate on the kinetics of desorption, which is also expected to influence the efficiency of certain processes, such as desorption by gas purge. PMID:23470206

  19. Patterns and Processes of Molecular Evolution in Rickettsia

    OpenAIRE

    Amiri, Haleh

    2002-01-01

    Species of the genus Rickettsia are obligate intracellular parasites of the a-proteobacterial subdivision. It has been suggested that obligate intracellular bacteria have evolved from free-living bacteria with much larger genome sizes. Transitions to intracellular growth habitats are normally associated with radical genomic alterations, particularly genome rearrangements and gene losses. This thesis presents a comparative study of evolutionary processes such as gene rearrangements, deletions ...

  20. Molecular basis of processing wheat gluten toward biobased materials.

    Science.gov (United States)

    Lagrain, Bert; Goderis, Bart; Brijs, Kristof; Delcour, Jan A

    2010-03-01

    The unique properties of the wheat grain reside primarily in the gluten-forming storage proteins of its endosperm. Wheat gluten's structural and functional properties have led to an expanding diversity of applications in food products. However, its viscoelastic properties and low water solubility also are very interesting features for nonfood applications. Moreover, gluten is annually renewable and perfectly biodegradable. In the processing and setting of gluten containing products, temperature plays a very important role. In this review, the structure and reactivity of gluten are discussed and the importance of sulfhydryl (SH) and disulfide (SS) groups is demonstrated. Wheat gluten aggregation upon thermosetting proceeds through direct covalent cross-linking in and between its protein groups, glutenin and gliadin. Predominant reactions include SH oxidation and SH/SS interchange reactions leading to the formation of SS cross-links. Additionally, thermal treatment of gluten can result in the formation of other than SS covalent bonds. We here review two main technological approaches to make gluten-based materials: wet processes resulting in thin films and dry processes, such as extrusion or compression molding, exploiting the thermoplastic properties of proteins under low moisture conditions and potentially resulting in very useful materials. Gluten bioplastics can also be reinforced with natural fibers, resulting in biocomposites. Although a lot of progress has been made the past decade, the current gluten materials are still outperformed by their synthetic polymer counterparts. PMID:20141101

  1. Molecular Studies on the Ecology of Listeria monocytogenes in the Smoked Fish Processing Industry

    OpenAIRE

    Norton, Dawn M.; Mccamey, Meghan A.; Gall, Kenneth L.; Scarlett, Janet M.; Boor, Kathryn J.; Wiedmann, Martin

    2001-01-01

    We have applied molecular approaches, including PCR-based detection strategies and DNA fingerprinting methods, to study the ecology of Listeria monocytogenes in food processing environments. A total of 531 samples, including raw fish, fish during the cold-smoking process, finished product, and environmental samples, were collected from three smoked fish processing facilities during five visits to each facility. A total of 95 (17.9%) of the samples tested positive for L. monocytogenes using a ...

  2. Control of molecular organization and energy level alignment by an electronically nanopatterned boron nitride template.

    Science.gov (United States)

    Joshi, Sushobhan; Bischoff, Felix; Koitz, Ralph; Ecija, David; Seufert, Knud; Seitsonen, Ari Paavo; Hutter, Jürg; Diller, Katharina; Urgel, José I; Sachdev, Hermann; Barth, Johannes V; Auwärter, Willi

    2014-01-28

    Suitable templates to steer the formation of nanostructure arrays on surfaces are indispensable in nanoscience. Recently, atomically thin sp(2)-bonded layers such as graphene or boron nitride (BN) grown on metal supports have attracted considerable interest due to their potential geometric corrugation guiding the positioning of atoms, metallic clusters or molecules. Here, we demonstrate three specific functions of a geometrically smooth, but electronically corrugated, sp(2)/metal interface, namely, BN/Cu(111), qualifying it as a unique nanoscale template. As functional adsorbates we employed free-base porphine (2H-P), a prototype tetrapyrrole compound, and tetracyanoquinodimethane (TCNQ), a well-known electron acceptor. (i) The electronic moirons of the BN/Cu(111) interface trap both 2H-P and TCNQ, steering self-organized growth of arrays with extended molecular assemblies. (ii) We report an effective decoupling of the trapped molecules from the underlying metal support by the BN, which allows for a direct visualization of frontier orbitals by scanning tunneling microscopy (STM). (iii) The lateral molecular positioning in the superstructured surface determines the energetic level alignment; i.e., the energy of the frontier orbitals, and the electronic gap are tunable. PMID:24328081

  3. Biodiversity at the Ecosystem Level - Patterns and Processes : Proceedings of the 2nd DanBIF conference, 26-27 April 2006, Aarhus University

    DEFF Research Database (Denmark)

    2009-01-01

    This publication contains the presentations and discussions from the second DanBIF conference, entitled Biodiversity at the Ecosystem Level – Patterns and Processes. The questions asked at this conference were: What is biodiversity at the ecosystem level? How is it related to biodiversity at other levels of organization? How may GBIF (Global Biodiversity Information Facility) deal with ecosystem level data and informatics? The conference had two important goals. The first was to present an overview of contemporary research related to ecosystem level biodiversity and the second was to help GBIF formulate a strategy for dealing with biodiversity above the species and molecular levels and make data available for the end-users.

  4. Quantum simulation and quantum information processing with molecular dipolar crystals

    International Nuclear Information System (INIS)

    In this thesis interactions between dipolar crystals and neutral atoms or separated molecules have been investigated. They were motivated to realize new kinds of lattice models in mixtures of atoms and polar molecules where an MDC functions as an underlying periodic lattice structure for the second species. Such models bring out the peculiar features of MDC's, that include a controllable, potentially sub-optical wavelength periodicity and strong particle phonon interactions. Only stable collisional configurations have been investigated, excluding chemical reactions between the substituents, and crystal distortions beyond the scope of perturbation theory. The system was treated in the polaron picture where particles of the second species are dressed by surrounding crystal phonons. To describe the competition between coherent and incoherent dynamics of the polarons, a master equation in the Brownian motion limit was used with phonons treated as a thermal heat bath. It was shown analytically that in a wide range of realistic parameters the corrections to the coherent time evolution are small, and that the dynamics of the dressed particles can be described by an effective extended Hubbard model with controllable system parameters. The last chapter of this thesis contains a proposal for QIP with cold polar molecules that, in contrast to previous works, uses an MDC as a quantum register. It was motivated by the unique features of dipolar molecules and to exploit the peculiapolar molecules and to exploit the peculiar physical conditions in dipolar crystals. In this proposal the molecular dipole moments were tailored by non-local fields to include a small, switchable, state-dependent dipole moment in addition to the large internal state independent moment that stabilizes the crystal. It was shown analytically that a controllable, non-trivial phonon-mediated interaction can be generated that exceeds non-trivial, direct dipole-dipole couplings. The addressability problem due to high crystal densities was overcome by the use of marker qubits that locally manipulate the phononic structure. This enabled the implementation of qubit operations in the crystal at pre-specified lattice site using otherwise global addressing only with negligible decoherence. Finally a specific two-layer setup is outlined that can be scaled to arbitrary sizes by including multi-layer structures realized under optical trapping conditions with multiple marker molecules. (author)

  5. Macro Level Simulation Model Of Space Shuttle Processing

    Science.gov (United States)

    2000-01-01

    The contents include: 1) Space Shuttle Processing Simulation Model; 2) Knowledge Acquisition; 3) Simulation Input Analysis; 4) Model Applications in Current Shuttle Environment; and 5) Model Applications for Future Reusable Launch Vehicles (RLV's). This paper is presented in viewgraph form.

  6. Effectiveness of the regulatory process at the international level

    International Nuclear Information System (INIS)

    A comparison between the regulatory review processes of the International Atomic Energy Agency and of the International Civil Aviation Organization is presented. Their differing approaches to audits are examined. (author)

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

    Science.gov (United States)

    Tycko, Robert

    2005-01-01

    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 that are applicable to amyloid samples prepared with isotopic labeling of specific sites and to samples prepared with uniform isotopic labeling of selected residues are presented, illustrating the utility of the various techniques and labeling schemes. Information regarding the preparation of amyloid samples for solid state NMR measurements is also included. PMID:17046393

  8. 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.

  9. Low-level radioactive waste from rare metals processing facilities

    International Nuclear Information System (INIS)

    This paper reviews the situations at the existing Teledyne Wah Chang Co., Inc. located at Albany, Oregon, and the former Carborundum Corp./Amax Specialty Metals, Inc., facilities located at Parkersburg, West Virginia, and Akron, New York, in order to show the extent of the radioactivity problem at rare metals processing facilities and the need to identify for radiological review other rare metal and rare earth processing sites

  10. Fast analysis of molecular dynamics trajectories with graphics processing units-Radial distribution function histogramming

    International Nuclear Information System (INIS)

    The calculation of radial distribution functions (RDFs) from molecular dynamics trajectory data is a common and computationally expensive analysis task. The rate limiting step in the calculation of the RDF is building a histogram of the distance between atom pairs in each trajectory frame. Here we present an implementation of this histogramming scheme for multiple graphics processing units (GPUs). The algorithm features a tiling scheme to maximize the reuse of data at the fastest levels of the GPU's memory hierarchy and dynamic load balancing to allow high performance on heterogeneous configurations of GPUs. Several versions of the RDF algorithm are presented, utilizing the specific hardware features found on different generations of GPUs. We take advantage of larger shared memory and atomic memory operations available on state-of-the-art GPUs to accelerate the code significantly. The use of atomic memory operations allows the fast, limited-capacity on-chip memory to be used much more efficiently, resulting in a fivefold increase in performance compared to the version of the algorithm without atomic operations. The ultimate version of the algorithm running in parallel on four NVIDIA GeForce GTX 480 (Fermi) GPUs was found to be 92 times faster than a multithreaded implementation running on an Intel Xeon 5550 CPU. On this multi-GPU hardware, the RDF between two selections of 1,000,000 atoms each can be calculated in 26.9 s per frame. The multi-GPU RDF algorithms describrame. The multi-GPU RDF algorithms described here are implemented in VMD, a widely used and freely available software package for molecular dynamics visualization and analysis.

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

    Energy Technology Data Exchange (ETDEWEB)

    Barnett, C.F.; Crandall, D.H.; Farmer, B.J. (comps.)

    1982-10-01

    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.

  12. A study on melting process of perylene using molecular dynamics simulation

    Directory of Open Access Journals (Sweden)

    M Peyvasteh

    2014-11-01

    Full Text Available Melting process of perylene is investigated using molecular dynamics simulation. Some of thermodynamic properties such as potential energy and transition order parameter are calculated as a function of temperature in the range of 500 K-600 K. These calculations are performed by two different methods in NPT and NVT ensembles. The selected interaction potential is Re-squared and the simulations are performed by LAMMPS (a classic molecular dynamics code. The results show that NPT ensemble is more appropraite for the study of melting process than NVT ensemble and shows a good agreement with experimental melting temperature.

  13. 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

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

    Directory of Open Access Journals (Sweden)

    Mamidala Praveen

    2012-01-01

    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.

  15. 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+

  16. Diagnosis Levels in Vocational Guidance and Placement Processes

    Science.gov (United States)

    Donoso, Trinidad; Figuera, Maria Pilar

    2007-01-01

    Career and employment counseling has been shown to be a key tool for assisting in processes of socio-professional placement. The objective of this article is to offer an innovative model of intervention that addresses the three vertices of labour market, social fabric and personal context, from which one can understand and globally analyze those…

  17. Telemetry downlink interfaces and level-zero processing

    Science.gov (United States)

    Horan, S.; Pfeiffer, J.; Taylor, J.

    1991-01-01

    The technical areas being investigated are as follows: (1) processing of space to ground data frames; (2) parallel architecture performance studies; and (3) parallel programming techniques. Additionally, the University administrative details and the technical liaison between New Mexico State University and Goddard Space Flight Center are addressed.

  18. The challenges for molecular nutrition research 3: comparative nutrigenomics research as a basis for entering the systems level.

    Science.gov (United States)

    Daniel, Hannelore; Drevon, Christian A; Klein, Ulla I; Kleemann, Robert; van Ommen, Ben

    2008-12-01

    Human nutrition and metabolism may serve as the paradigm for the complex interplay of the genome with its environment. The concept of nutrigenomics now enables science with new tools and comprehensive analytical techniques to investigate this interaction at all levels of the complexity of the organism. Moreover, nutrigenomics seeks to better define the homeostatic control mechanisms, identify the de-regulation in the early phases of diet-related diseases, and attempts to assess to what extent an individual's sensitizing genotype contributes to the overall health or disease state. In a comparative approach nutrigenomics uses biological systems of increasing complexity from yeast to mammalian models to define the general rules of metabolic and genetic mechanisms in adaptations to the nutritional environment. Powerful information technology, bioinformatics and knowledge management tools as well as new mathematical and computational approaches now make it possible to study these molecular mechanisms at the cellular, organ and whole organism level and take it on to modeling the processes in a "systems biology" approach. This review summarizes some of the concepts of a comparative approach to nutrigenomics research, identifies current lacks and proposes a concerted scientific effort to create the basis for nutritional systems biology. PMID:18830658

  19. Implications of the admixture process in skin color molecular assessment.

    Science.gov (United States)

    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

    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

  20. Investigation of material removal mechanism of silicon wafer in the chemical mechanical polishing process using molecular dynamics simulation method

    Science.gov (United States)

    Han, Xuesong; Hu, Yuanzhong; Yu, Siyuan

    2009-06-01

    Chemical mechanical polishing (CMP) technology, being the mainstream technique of acquiring global planarization and nanometer level surface, has already become an attractive research item. In the case of CMP process, the indentation depth lies in the range of nanometer or sub-nanometer, huge hydrostatic pressure induced in the local deformation area which makes the material removal and surface generation process different from traditional manufacturing process. In order to investigate the physical essence of CMP technique, the authors carry out molecular dynamics (MD) analysis of chemical mechanical polishing of a silicon wafer. The simulation result shows that huge hydrostatic pressure is induced in the local area and leads to the silicon atom transform from the classical diamond structure ( ? silicon) to metal structure ( ? silicon). This important factor results in the ductile fracture of silicon and then in the acquisition of a super-smooth surface.

  1. Heterogeneity of innovative, collaborative, and productive firm-level processes

    OpenAIRE

    Amoroso, S.

    2013-01-01

    This thesis addresses a set of interrelated topics that contribute to both structural and empirical fields of the economics of innovation. First, we consider the role of imperfect competition in product and labor markets in shaping the productivity of a firm. Second, we model and evaluate the expected correlations present among firms' R&D cooperative choices due to both firm- and sector-level heterogeneity. In the last study, we develop and estimate a structural dynamic monopoly model to quan...

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

    Science.gov (United States)

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

    2014-10-23

    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

  3. Method of processing high level radioactive wastes by glass solidification

    International Nuclear Information System (INIS)

    Purpose: To enable complete and rapid issue and interruption of molten glass, as well as enable safety and reliable supply of high-level-waste-containing glass or crystallized glass into canister with no aids of manual operation. Method: High level radioactive wastes-containing glasses are melted in a glass melting furnace which has a downwardly projecting heat resistance metal nozzle disposed to the bottom of the furnace, then flown out by passing electrical current to the nozzle and then supplied to a container placed under the nozzle. When the molten glass reaches a predetermined amount in the container, the electrical supply to the nozzle is interrupted and the nozzle is cooled. When the nozzle temperature lowers to such a level that is capable of cutting the glass, the flown out glass is cut by a cutter disposed near the lower end of the nozzle and, simultaneously, the pressure in the melting furnace is reduced to suck the molten glass in the nozzle thereby interrupting flowing out of the glass. (Horiuchi, T.)

  4. Advances in low-level color image processing

    CERN Document Server

    Smolka, Bogdan

    2014-01-01

    Color perception plays an important role in object recognition and scene understanding both for humans and intelligent vision systems. Recent advances in digital color imaging and computer hardware technology have led to an explosion in the use of color images in a variety of applications including medical imaging, content-based image retrieval, biometrics, watermarking, digital inpainting, remote sensing, visual quality inspection, among many others. As a result, automated processing and analysis of color images has become an active area of research, to which the large number of publications of the past two decades bears witness. The multivariate nature of color image data presents new challenges for researchers and practitioners as the numerous methods developed for single channel images are often not directly applicable to multichannel  ones. The goal of this volume is to summarize the state-of-the-art in the early stages of the color image processing pipeline.

  5. Level 1 remedial investigation work plan, 300 Area Process Ponds

    Energy Technology Data Exchange (ETDEWEB)

    1987-06-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-02-21

    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).

  7. On reproduction in red algae: further research needed at the molecular level.

    Science.gov (United States)

    García-Jiménez, Pilar; Robaina, Rafael R

    2015-01-01

    Multicellular red algae (Rhodophyta) have some of the most complex life cycles known in living organisms. Economically valuable seaweeds, such as phycocolloid producers, have a triphasic (gametophyte, carposporophyte, and tetrasporophyte) life cycle, not to mention the intricate alternation of generations in the edible "sushi-alga" nori. It is a well-known fact that reproductive processes are controlled by one or more abiotic factor(s), including day length, light quality, temperature, and nutrients. Likewise, endogenous chemical factors such as plant growth regulators have been reported to affect reproductive events in some red seaweeds. Still, in the genomic era and given the high throughput techniques at our disposal, our knowledge about the endogenous molecular machinery lags far behind that of higher plants. Any potential effective control of the reproductive process will entail revisiting most of these results and facts to answer basic biological questions as yet unresolved. Recent results have shed light on the involvement of several genes in red alga reproductive events. In addition, a working species characterized by a simple filamentous architecture, easy cultivation, and accessible genomes may also facilitate our task. PMID:25755663

  8. The interaction of CO2 with amines as molecular control factor in catalytic processes

    OpenAIRE

    Wispelaere, Irene Martine

    2014-01-01

    The present thesis deals with the interaction of CO2 and amines as molecular control factor to influence different kinds of selectivities in various catalytic processes. The reversibility of the Lewis acid-base reaction between CO2 and amines has been applied in numerous reaction and separation processes and chapter I gives a short overview of the different areas. Up to date this interaction has not been used to steer the selectivity of a reaction and in this context, switchable solvents are ...

  9. Molecular Chemical Engines: Pseudo-Static Processes and the Mechanism of Energy Transduction

    OpenAIRE

    Sasaki, Kazuo

    2005-01-01

    We propose a simple theoretical model for a molecular chemical engine that catalyzes a chemical reaction and converts the free energy released by the reaction into mechanical work. Binding and unbinding processes of reactant and product molecules to and from the engine are explicitly taken into account. The work delivered by the engine is calculated analytically for infinitely slow (``pseudo-static'') processes, which can be reversible (quasi-static) or irreversible, control...

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

    OpenAIRE

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

    2011-01-01

    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...

  11. 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)

  12. 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

  13. Corrosion and failure processes in high-level waste tanks

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-11-01

    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.

  14. Solution-phase laser processing of ?-conjugated polymers: Switching between different molecular states

    International Nuclear Information System (INIS)

    Liquid-phase laser processing, where the laser-irradiated target material is immersed in water for cooling, has been reported as a promising processing technique for thermally fragile organic materials. Although nanometer-sized particles have been reported to be obtained with the liquid-phase laser processing, the physical property did not change because quantum-mechanical size effect does not exhibit itself in the zero-radius Frenkel excitons. In the present study, we step further to use solution droplets as a target material, where organic molecules are molecularly dispersed in organic solvent and, therefore, expected to easily alter the conformation and the energy state upon laser irradiation. Small volume organic solvent is quickly evaporated upon laser irradiation, letting the bare organic molecule placed in water and rapidly cooled. To prevent the chemical decomposition of the target ?-conjugated molecule, the specimen was resonantly irradiated by a ns-pulse green laser, not by a conventional UV laser. When the solid state spin-coat film made from MEH-PPV chloroform solution was used as a irradiation target immersed in water, resulting MEH-PPV particles showed similar photoluminescence (PL) like the PL of the spin-coat film and PL of the chloroform solution, including the 0?1, 0?2 vibrational transitions: this indicates that the energy levels were not modified from the spin-coat film. In comparison, when tiny droplets of MEH-PPV chloroform solution (orange MEH-PPV chloroform solution (orange color) were suspended in water, laser irradiation gave rise to yellow MEH-PPV particles which showed 550 nm and 530 nm PL (type B), blue-shifted from the spin-coat film PL 580 nm (type A), suggesting a successful phase transition of MEH-PPV polymer to type B. Further solution-phase laser processing left the type B state unchanged. The irreversible phase transition from type A to type B suggests that the type B ground state has lower energy than type A, which is consistent with the blue-shifted PL of type B, provided that the excited state energy is similar between the two states. Thermal annealing up to 200°C of type A state did not give rise to type B state, which indicates that the activation potential between the two states is higher than the thermal energy at 200°C, and that only the proposed solution-phase laser processing enables the system to cross over this potential.

  15. 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.)

  16. 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)

    Rolando A, Hernández Fernández.

    2014-02-01

    Full Text Available 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.

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

    Science.gov (United States)

    Habeeb, Zeeshan

    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.

  18. 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

  19. 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)

  20. High levels of melatonin generated during the brewing process.

    Science.gov (United States)

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

    2013-08-01

    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

  1. Investigating the Formation of Helical States in the Process of Homopolymer Collapse using Molecular Dynamics Simulations

    Directory of Open Access Journals (Sweden)

    M. Bouarkat

    2010-01-01

    Full Text Available The molecular process of homopolymer collapse was numerically modelled through isothermal molecular dynamics simulations. The initial polymer chains were constructed, using random walks in continuum space. A simple harmonic potential was used in order to represent short range interactions between monomers. Measurement of the conformational properties of the polymer during the collapse was performed, while different collapse pathways were also observed. Specifically the spontaneous collapse of the polymer to helical states occurred at low temperatures. It may be concluded that the numerical results are in perfect agreement with those of Langevin dynamics simulations conducted in a previous study.

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

    Directory of Open Access Journals (Sweden)

    Bong K. Choi

    2006-01-01

    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.

  3. Mass spectrometry in nutrition: understanding dietary health effects at the molecular level.

    Science.gov (United States)

    Kussmann, Martin; Affolter, Michael; Nagy, Kornél; Holst, Birgit; Fay, Laurent B

    2007-01-01

    In modern nutrition research, mass spectrometry has developed into a tool to assess health, sensory as well as quality and safety aspects of food. In this review, we focus on health-related benefits of food components and, accordingly, on biomarkers of exposure (bioavailability) and bioefficacy. Current nutrition research focuses on unraveling the link between dietary patterns, individual foods or food constituents and the physiological effects at cellular, tissue and whole body level after acute and chronic uptake. The bioavailability of bioactive food constituents as well as dose-effect correlations are key information to understand the impact of food on defined health outcomes. Both strongly depend on appropriate analytical tools to identify and quantify minute amounts of individual compounds in highly complex matrices--food or biological fluids--and to monitor molecular changes in the body in a highly specific and sensitive manner. Based on these requirements, mass spectrometry has become the analytical method of choice with broad applications throughout all areas of nutrition research. The current review focuses on selected areas of application: protein and peptide as well as nutrient and metabolite analysis. PMID:17654467

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

    DEFF Research Database (Denmark)

    Lecroq, Beatrice; Gooday, Andrew John

    2009-01-01

    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.

  5. Articular Joint Lubricants during Osteoarthritis and Rheumatoid Arthritis Display Altered Levels and Molecular Species

    Science.gov (United States)

    Liebisch, Gerhard; Zhang, Ruiyan; Siebert, Hans-Christian; Wilhelm, Jochen; Kaesser, Ulrich; Dettmeyer, Reinhard B.; Klein, Heiko; Ishaque, Bernd; Rickert, Markus; Schmitz, Gerd; Schmidt, Tannin A.; Steinmeyer, Juergen

    2015-01-01

    Background Hyaluronic acid (HA), lubricin, and phospholipid species (PLs) contribute independently or together to the boundary lubrication of articular joints that is provided by synovial fluid (SF). Our study is the first reporting quantitative data about the molecular weight (MW) forms of HA, lubricin, and PLs in SF from cohorts of healthy donors, patients with early (eOA)- or late (lOA)-stage osteoarthritis (OA), and patients with active rheumatoid arthritis (RA). Methods We used human SF from unaffected controls, eOA, lOA, and RA. HA and lubricin levels were measured by enzyme-linked immunosorbent assay. PLs was quantified by electrospray ionization tandem mass spectrometry. Fatty acids (FAs) were analyzed by gas chromatography, coupled with mass spectrometry. The MW distribution of HA was determined by agarose gel electrophoresis. Results Compared with control SF, the concentrations of HA and lubricin were lower in OA and RA SF, whereas those of PLs were higher in OA and RA SF. Moreover, the MW distribution of HA shifted toward the lower ranges in OA and RA SF. We noted distinct alterations between cohorts in the relative distribution of PLs and the degree of FA saturation and chain lengths of FAs. Conclusions The levels, composition, and MW distribution of all currently known lubricants in SF—HA, lubricin, PLs—vary with joint disease and stage of OA. Our study is the first delivering a comprehensive view about all joint lubricants during health and widespread joint diseases. Thus, we provide the framework to develop new optimal compounded lubricants to reduce joint destruction. PMID:25933137

  6. A methodology to assess the maturity level of brewery business processes

    OpenAIRE

    Armenda?riz, Mikel

    2010-01-01

    The purpose of this project is to develop a procedure to assess the maturity level of the brewery business processes to be able to determine the required level of process automation & IT for a brewery.This procedure is made up by several tailored questionnaires that have been based on the Process and Enterprise Maturity Model management assessment tool. This tool is described in the article called The Process Audit written by Michael Hammer and published by Harvard Business Review in 2007...

  7. Quantitative Proteomics Analysis Reveals Molecular Networks Regulated by Epidermal Growth Factor Receptor Level in Head and Neck Cancer

    OpenAIRE

    Yang, Wei; Cai, Quan; Lui, Vivian W.Y.; Everley, Patrick A.; Kim, Jayoung; Bhola, Neil; Quesnelle, Kelly M.; Zetter, Bruce R.; Steen , Hanno; Freeman, Michael R; Grandis, Jennifer R.

    2010-01-01

    Epidermal growth factor receptor (EGFR) is overexpressed in up to 90% of head and neck cancer (HNC), where increased expression levels of EGFR correlate with poor prognosis. To date, EGFR expression levels have not predicted the clinical response to the EGFR-targeting therapies. Elucidation of the molecular mechanisms underlying anti-EGFR-induced antitumor effects may shed some light on the mechanisms of HNC resistance to EGFR-targeting therapeutics and provide novel targets for improving the...

  8. Multiprobe spectroscopic investigation of molecular-level behavior within aqueous 1-butyl-3-methylimidazolium tetrafluoroborate.

    Science.gov (United States)

    Sarkar, Abhra; Ali, Maroof; Baker, Gary A; Tetin, Sergey Y; Ruan, Qiaoqiao; Pandey, Siddharth

    2009-03-12

    In this work, an array of molecular-level solvent features--including solute--solvent/solvent--solvent interactions, dipolarity, heterogeneity, dynamics, probe accessibility, and diffusion--were investigated across the entire composition of ambient mixtures containing the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate, [bmim][BF4], and pH 7.0 phosphate buffer, based on results assembled for nine different molecular probes utilized in a range of spectroscopic modes. These studies uncovered interesting and unusual solvatochromic probe behavior within this benchmark mixture. Solvatochromic absorbance probes--a water-soluble betaine dye (betaine dye 33), N,N-diethyl-4-nitroaniline, and 4-nitroaniline--were employed to determine ET (a blend of dipolarity/polarizability and hydrogen bond donor contributions) and the Kamlet-Taft indices pi* (dipolarity/polarizability), alpha (hydrogen bond donor acidity), and beta (hydrogen bond acceptor basicity) characterizing the [bmim][BF4] + phosphate buffer system. These parameters each showed a marked deviation from ideality, suggesting selective solvation of the individual probe solutes by [bmim][BF4]. Similar conclusions were derived from the responses of the fluorescent polarity-sensitive probes pyrene and pyrene-1-carboxaldehyde. Importantly, the fluorescent microfluidity probe 1,3-bis(1-pyrenyl)propane senses a microviscosity within the mixture that significantly exceeds expectations derived from simple interpolation of the behavior in the neat solvents. On the basis of results from this probe, a correlation between microviscosity and bulk viscosity was established; pronounced solvent-solvent hydrogen-bonding interactions were implicit in this behavior. The greatest deviation from ideal additive behavior for the probes studied herein was consistently observed to occur in the buffer-rich regime. Nitromethane-based fluorescence quenching of pyrene within the [bmim][BF4] + phosphate buffer system showed unusual compliance with a "sphere-of-action" quenching model, a further manifestation of the microheterogeneity of the system. Fluorescence correlation spectroscopic results for both small (BODIPY FL) and macromolecular (Texas Red-10 kDa dextran conjugate) diffusional probes provide additional evidence in support of microphase segregation inherent to aqueous [bmim] [BF4]. PMID:19260713

  9. An overview of atomic and molecular processes in critical velocity ionization

    International Nuclear Information System (INIS)

    Alfven's critical ionization velocity (CIV) is a multistep process involving plasma physics and plasma chemistry. The authors present an overview of the time development of some atomic and molecular processes in CIV. In the pre-onset stage, metastable states play an important role: They provide an energy pooling mechanism allowing low energy electrons to participate in the ionization processes; they may explain the low energy threshold as well as the fast time scale in the onset of CIV. For a sustaining CIV to occur, Townsend's criterion has to be satisfied. The kinetic energies of the neutrals are transformed to plasma wave energies via beam-plasma instabilities, and the plasma waves that heat the electrons result in a tail formation. Excitation of neutrals with subsequent radiation is an important energy loss mechanism. Finite beam size also limits the instability growth rate. In the propagation of CIV, ion-molecule reactions and molecular dissociative recombination are important. Ion-molecule reactions change the temporal chemical composition in a CIV process and help explain some results in CIV experiments. Molecular dissociative recombination reduces the plasma density, lowers the effective neutral mass, and loses energy via excitation and radiation; it tends to quench the propagation of CIV. Depending on various parameters, oscillatory behavior of CIV may occur

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

    Directory of Open Access Journals (Sweden)

    Sherwood Julie S

    2009-09-01

    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.

  11. Molecular Basis of a Million-Fold Affinity Maturation Process in a Protein-Protein Interaction

    Energy Technology Data Exchange (ETDEWEB)

    D Bonsor; S Postel; B Pierce; N Wang; P Zhu; R Buonpane; Z Weng; D Kranz; E Sundberg

    2011-12-31

    Protein engineering is becoming increasingly important for pharmaceutical applications where controlling the specificity and affinity of engineered proteins is required to create targeted protein therapeutics. Affinity increases of several thousand-fold are now routine for a variety of protein engineering approaches, and the structural and energetic bases of affinity maturation have been investigated in a number of such cases. Previously, a 3-million-fold affinity maturation process was achieved in a protein-protein interaction composed of a variant T-cell receptor fragment and a bacterial superantigen. Here, we present the molecular basis of this affinity increase. Using X-ray crystallography, shotgun reversion/replacement scanning mutagenesis, and computational analysis, we describe, in molecular detail, a process by which extrainterfacial regions of a protein complex can be rationally manipulated to significantly improve protein engineering outcomes.

  12. A Better Insight Into IT Contribution by Process Level Structure : A Case Study in Royal Greenland

    DEFF Research Database (Denmark)

    Shahim, Nazli; MØller, Charles

    2013-01-01

    Creation of IT business value through its impact on value chain processes made the objective of this research to compare and differentiate IT role at both process and firm levels. A discussion about IT’s impact at both levels are made through previous theoretical and empirical studies. The discussion is supported by an introduction to the case of study in Royal Greenland. The contribution of this paper is the results of the discussions and the case study reaching to the point that IT supporting influences are better understood and observed at process levels rather than firm output level.

  13. 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

  14. Molecular Tools for the Selective Detection of Nine Diatom Species Biomarkers of Various Water Quality Levels

    Directory of Open Access Journals (Sweden)

    Lucia Cimarelli

    2015-05-01

    Full Text Available Our understanding of the composition of diatom communities and their response to environmental changes is currently limited by laborious taxonomic identification procedures. Advances in molecular technologies are expected to contribute more efficient, robust and sensitive tools for the detection of these ecologically relevant microorganisms. There is a need to explore and test phylogenetic markers as an alternative to the use of rRNA genes, whose limited sequence divergence does not allow the accurate discrimination of diatoms at the species level. In this work, nine diatom species belonging to eight genera, isolated from epylithic environmental samples collected in central Italy, were chosen to implement a panel of diatoms covering the full range of ecological status of freshwaters. The procedure described in this work relies on the PCR amplification of specific regions in two conserved diatom genes, elongation factor 1-a (eEF1-a and silicic acid transporter (SIT, as a first step to narrow down the complexity of the targets, followed by microarray hybridization experiments. Oligonucleotide probes with the potential to discriminate closely related species were designed taking into account the genetic polymorphisms found in target genes. These probes were tested, refined and validated on a small-scale prototype DNA chip. Overall, we obtained 17 highly specific probes targeting eEF1-a and SIT, along with 19 probes having lower discriminatory power recognizing at the same time two or three species. This basic array was validated in a laboratory setting and is ready for tests with crude environmental samples eventually to be scaled-up to include a larger panel of diatoms. Its possible use for the simultaneous detection of diatoms selected from the classes of water quality identified by the European Water Framework Directive is discussed.

  15. A fully quantal molecular description for the spectra of bosons and fermions in the lowest Landau level

    CERN Document Server

    Yannouleas, Constantine

    2010-01-01

    Through the introduction of a class of appropriate translationally invariant trial wave functions, we show that the strong correlations in the lowest Landau level (LLL) reflect in finite systems the emergence of intrinsic point-group symmetries associated with rotations and vibrations of molecules formed through particle localization. This quantal molecular description is universal, being valid for both bosons and fermions, for both the yrast and excited states of the LLL spectra, and for both low and high angular momenta. "Quantum-fluid" physical pictures associated with Jastrow-type trial functions are shown to be reducible to the molecular description introduced in this paper.

  16. Biologia molecular do processo de infecção por Agrobacterium spp. / Molecular biology of the infection process by Agrobacterium spp.

    Scientific Electronic Library Online (English)

    Gisele M. de, Andrade; Laudete M., Sartoretto; Ana C. M., Brasileiro.

    2003-10-01

    Full Text Available Agrobacterium tumefaciens é o agente causal da galha-da-coroa, doença que afeta a maioria das plantas dicotiledôneas e caracteriza-se pelo crescimento de tumores na junção entre o caule e a raiz (coroa). A formação desses tumores é o resultado de um processo natural de transferência de genes de Agro [...] bacterium spp. para o genoma da planta infetada. Esses genes estão contidos em um plasmídio de alto peso molecular (120 a 250 kb), denominado Ti ("tumor inducing"), presente em todas as linhagens patogênicas de Agrobacterium spp. Duas regiões do plasmídio Ti estão diretamente envolvidas na indução do tumor: a região-T, que corresponde ao segmento de DNA transferido para a célula vegetal, e a região de virulência (região vir), que contém genes envolvidos na síntese de proteínas responsáveis pelo processo de transferência da região-T. Esta região, uma vez transferida e integrada no genoma da célula vegetal, passa a ser denominada de T-DNA ("transferred DNA"). Os genes presentes no T-DNA codificam enzimas envolvidas na via de biossíntese de reguladores de crescimento, auxinas e citocininas. A síntese desses reguladores pelas células transformadas causa um desbalanço hormonal, levando à formação do tumor no local da infecção. Outro grupo de genes presentes no T-DNA codifica enzimas responsáveis pela síntese de opinas, que são catabolisadas especificamente pela bactéria colonizadora, como fonte de nutrientes. O conhecimento preliminar das bases moleculares envolvidas no processo de infecção de uma planta hospedeira por Agrobacterium spp., permitiu a utilização desta bactéria como vetor natural de transformação genética de plantas. Abstract in english Agrobacterium tumefaciens is the causal agent of crown gall disease that affects most dicotyledonous plants and is characterized by growth of tumors in the region between the plant stem and root (crown). The development of tumors is the result of a natural transfer process of Agrobacterium spp. gene [...] s to the genome of the infected plant. These genes are found on a high molecular weight plasmid denominated Ti (tumor inducing), present in all pathogenic Agrobacterium spp. strains. Two Ti plasmid regions are directly involved in tumor induction. The T-region, which corresponds to the segment of transferred DNA to the plant cells, and the virulence (vir) region, which contains genes involved in the synthesis of proteins required for T-region transfer. This region, when transferred and integrated to the plant cell genome, is called T-DNA (transferred DNA). The genes present in T-DNA encode enzymes involved in the biosynthesis of plant growth regulators, auxin and cytokinin. The synthesis of these regulators by transformed cells results in a hormonal inbalance, leading to the development of tumors where the infection took place. Another group of genes present in T-DNA encodes enzymes required for opine synthesis, which are specifically catabolised by the colonizing bacterium as the source of nutrients. Preliminary knowledge of the molecular basis involved in the infection process of the host plant by Agrobacterium spp. allowed the use of this bacterium as a natural vector for plant genetic transformation.

  17. Molecular dissection of abnormal wound healing processes resulting in keloid disease.

    Science.gov (United States)

    Shih, Barbara; Garside, Elloise; McGrouther, Duncan Angus; Bayat, Ardeshir

    2010-01-01

    Keloids are locally aggressive scars that typically invade into healthy surrounding skin and cause both physical and psychosocial distress to the patient. These pathological scars occur following minimal skin trauma after a variety of causes including burns and trauma. Although the pathogenesis of keloid disease is not well understood, it is considered to be the end product of an abnormal healing process. The aim of this review was to investigate the molecular and cellular pathobiology of keloid disease in relation to the normal wound healing process. The molecular aberrances in keloids that correlate with the molecular mechanisms in normal wound healing can be categorized into three groups: (1) extracellular matrix proteins and their degradation, (2) cytokines and growth factors, and (3) apoptotic pathways. With respect to cellular involvements, fibroblasts are the most well-studied cell population. However, it is unclear whether the fibroblast is the causative cell; they are modulated by other cell populations in wound repair, such as keratinocytes and macrophages. This review presents a detailed account of individual phases of the healing process and how they may potentially be implicated in aberrant raised scar formation, which may help in clarifying the mechanisms involved in keloid disease pathogenesis. PMID:20002895

  18. Molecular dynamics simulations of the relaxation processes in the condensed matter on GPUs

    Science.gov (United States)

    Morozov, I. V.; Kazennov, A. M.; Bystryi, R. G.; Norman, G. E.; Pisarev, V. V.; Stegailov, V. V.

    2011-09-01

    We report on simulation technique and benchmarks for molecular dynamics simulations of the relaxation processes in solids and liquids using the graphics processing units (GPUs). The implementation of a many-body potential such as the embedded atom method (EAM) on GPU is discussed. The benchmarks obtained by LAMMPS and HOOMD packages for simple Lennard-Jones liquids and metals using EAM potentials are presented for both Intel CPUs and Nvidia GPUs. As an example the crystallization rate of the supercooled Al melt is computed.

  19. R-matrix theory of atomic collisions. Application to atomic, molecular and optical processes

    Energy Technology Data Exchange (ETDEWEB)

    Burke, Philip G. [Queen' s Univ., Belfast (United Kingdom). School of Mathematics and Physics

    2011-07-01

    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 technological importance. Basic mathematical results and general and widely used R-matrix computer programs are summarized in the appendices. (orig.)

  20. Phase behaviour of macromolecular liquid crystalline materials. Computational studies at the molecular level

    CERN Document Server

    Stimson, L M

    2003-01-01

    Molecular simulations provide an increasingly useful insight into the static and dynamic characteristics of materials. In this thesis molecular simulations of macro-molecular liquid crystalline materials are reported. The first liquid crystalline material that has been investigated is a side chain liquid crystal polymer (SCLCP). In this study semi-atomistic molecular dynamics simulations have been conducted at a range of temperatures and an aligning potential has been applied to mimic the effect of a magnetic field. In cooling the SCLCP from an isotropic melt, microphase separation was observed yielding a domain structure. The application of a magnetic field to this structure aligns the domains producing a stable smectic mesophase. This is the first study in which mesophases have been observed using an off-lattice model of a SCLCP. The second material that has been investigated is a dendrimer with terminal mesogenic functionalization. Here, a multi-scale approach has been taken with Monte Carlo studies of a s...

  1. THE APPLICATION OF FEATURE TECHNOLOGY IN DEVELOPING A CAD-BASED HIGH LEVEL PROCESS PLANNING SYSTEM

    Directory of Open Access Journals (Sweden)

    Ade Febransyah

    2005-01-01

    Full Text Available High-level process planning plays an important role in determining candidate process domains at the configuration design stage. Changing the process domains later increases the product development cycle and the product development cost. Therefore, determining the most appropriate manufacturing processes at the beginning stages of the design process becomes critical. However, high-level process planning systems have traditionally lacked integration of design synthesis and design evaluation. The objective of this paper is to propose a CAD-based high-level process planning system that will help designers decide whether or not the designs are worth pursuing. A hybrid approach incorporating design by feature and feature recognition approaches is proposed and implemented. Synergizing both advantages of both approaches will reduce the complexity of feature recognition algorithm without sacrificing the flexibility in creating a part model.

  2. Quantal molecular description and universal aspects of the spectra of bosons and fermions in the lowest Landau level

    CERN Document Server

    Yannouleas, Constantine

    2010-01-01

    Through the introduction of a class of trial wave functions portraying combined rotations and vibrations of molecules formed through particle localization in concentric polygonal rings, a correlated basis is constructed that spans the translationally invariant part of the lower-Landau-level (LLL) spectra. These trial functions, referred to as rovibrational molecular (RVM) functions, generalize our previous work which focused exclusively on electronic cusp states, describing them as pure vibrationless rotations. From a computational viewpoint, the RVM correlated basis enables controlled and systematic improvements of the original strongly-correlated variational wave function. Conceptually, it provides the basis for the development of a quantal molecular description for the full LLL spectra. This quantal molecular description is universal, being valid for both bosons and fermions, for both the yrast and excited states of the LLL spectra, and for both low and high angular momenta. Furthermore, it follows that al...

  3. Sustained high levels of neuroprotective, high molecular weight, phosphorylated tau in the longest-lived rodent.

    Science.gov (United States)

    Orr, Miranda E; Garbarino, Valentina R; Salinas, Angelica; Buffenstein, Rochelle

    2015-03-01

    Tau protein is primarily expressed in neuronal axons and modulates microtubule stability. Tau phosphorylation, aggregation, and subcellular mislocalization coincide with neurodegeneration in numerous diseases, including Alzheimer's disease (AD). During AD pathogenesis, tau misprocessing accompanies Aß accumulation; however, AD animal models, despite elevated Aß, fail to develop tauopathy. To assess whether lack of tau pathology is linked to short life span common to most AD models, we examined tau processing in extraordinarily long-lived, mouse-sized naked mole-rats (NMRs; approximately 32 years), which express appreciable levels of Aß throughout life. We found that NMRs, like other mammals, display highest tau phosphorylation during brain development. Although tau phosphorylation decreases with aging, unexpectedly adult NMRs have higher levels than transgenic mice overexpressing mutant human tau. However, in sharp contrast with the somatodendritic accumulation of misprocessed tau in the transgenic mice, NMRs maintain axonal tau localization. Intriguingly, the adult NMR tau protein is 88 kDa, much larger than 45-68 kDa tau expressed in other mammals. We propose that this 88 kDa tau protein may offer exceptional microtubule stability and neuroprotection against lifelong, elevated Aß. PMID:25576082

  4. 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.

    Science.gov (United States)

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

    2009-09-01

    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 production. Our goal was to complete greater than 90% of the molecular tests in less than 3 days. The project required cooperation from different laboratory disciplines as well as individuals outside of the laboratory. The redesigned processes involved defining and standardizing the protocols and approaching blood and tissue specimens as analytes for molecular testing. The LEAN process resulted in fewer steps, approaching the ideal of a one-piece flow for specimens through collection/retrieval, transport, and different aspects of the testing process. The outcome of introducing the LEAN process has been a 44% reduction in molecular test turnaround time for tissue specimens, from an average of 2.7 to 1.5 days. In addition, extending LEAN work principles to the clinician suppliers has resulted in a markedly increased number of properly collected and shipped blood specimens (from 50 to 87%). These continuous quality improvements were accomplished by empowered workers in a blame-free environment and are now being sustained with minimal management involvement. PMID:19661386

  5. 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

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

    2009-01-01

    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...

  6. 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

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

    Directory of Open Access Journals (Sweden)

    Cusick Michael E

    2007-10-01

    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.

  8. 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)

    Jiang, Xiaoming; Zhou, Xiaolin

    2012-01-01

    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…

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

    Science.gov (United States)

    Kinaci, Alper

    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.

  10. Amino Acid Composition, Molecular Weight Distribution and Antioxidant Stability of Shrimp Processing Byproduct Hydrolysate

    Directory of Open Access Journals (Sweden)

    J.X. Jiang

    2011-01-01

    Full Text Available Protein hydrolysate have many practical applications in a various of industries due to the bioactive peptides related to their amino acid composition, sequence and molecular weight. The amino acid composition, molecular weight distribution and antioxidant stability of alcalase hydrolysate were investigated in this study. The hydrolysate was separated into five fractions by ultra filtration system with different molecular weight cutoff with 10, 5, 3 and 1 kDa, respectively. The protein content, 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and molecular weight of each fraction were determined. In addition, the antioxidant stability of the hydrolysate under several operating conditions was studied. The results showed that the hydrolysate was composed with high amounts of hydrophobic amino acids (40.4% which might contribute to the high antioxidant activity. The fraction with molecular weight lower than 1 kDa exhibited the highest antioxidative activity among the five fractions. The antioxidant stability experiments showed that the hydrolysate was stable when it was heated up to 100C and the relative antioxidative activity could be maintained nearly 70% at very low pH of 2.0. Glucose and sucrose had negative effects on the antioxidative activity, in which the relative activity of about 80% was retained. Sodium chloride and sodium benzoate had little or no effects on the antioxidative activity of the hydrolysate. The effects of Zn2+ and Cu2+ on the antioxidative activity were significant and dependent on metal concentration. The shrimp processing byproduct hydrolysate may be a potential natural food antioxidant in the future.

  11. Experiments on the Dynamics of Molecular Processes: a Chronicle of Fifty Years

    Science.gov (United States)

    Boato, Giovanni; Volpi, Gian Gualberto

    1999-10-01

    This paper reviews the way in which, in the Italy of the years immediately after World War II, interest in the dynamics of molecular processes was awakened. The narrative begins with the work of a small number of chemists and physicists who, in the initial stage, interacted closely. In the course of the years, their interests diverged and younger people joined the newly formed groups. Even now, after half a century, a common approach can still to be seen regarding how to attack problems and perform experiments. Experimental work is discussed, bringing out the common viewpoint of fields as diverse as mass spectrometry, isotope effects, chemical kinetics, molecular beams, molecule-molecule interactions, molecule-ion interactions, molecule-surface interactions, and plasma chemistry.

  12. In Situ Microscopic Observation of the Crystallization Process of Molecular Microparticles by Fluorescence Switching.

    Science.gov (United States)

    Ye, Xin; Liu, Yang; Lv, Yun; Liu, Guangfeng; Zheng, Xiaoxin; Han, Quanxiang; Jackson, Kenneth A; Tao, Xutang

    2015-06-26

    To clearly understand the solid-state amorphous-to-crystalline transformation is a long-standing challenge because such crystallization occuring in confined environments is difficult to observe directly. We developed an in situ and real-time imaging procedure to record the interface evolution in a solid-state crystallization of molecular amorphous particles. The method, by employing a tetra-substituted ethene with novel morphology-dependent fluorescence, which can distinguish the interfaces between the crystalline and amorphous phase by fluorescence color, is a simple and practical method to probe the inner process of a molecular microparticle. The crystallization of amorphous microparticles in different cases was clearly recorded, where the perfect microparticles and those with defects demonstrate diverse destinies. The details disclosed in this observation will deepen the understanding for a series of solid-state crystallization that we know little about before. PMID:25974083

  13. A fully quantal molecular description for the spectra of bosons and fermions in the lowest Landau level

    OpenAIRE

    Yannouleas, Constantine; landman, Uzi

    2009-01-01

    Through the introduction of a class of appropriate translationally invariant trial wave functions, we show that the strong correlations in the lowest Landau level (LLL) reflect in finite systems the emergence of intrinsic point-group symmetries associated with rotations and vibrations of molecules formed through particle localization. This quantal molecular description is universal, being valid for both bosons and fermions, for both the yrast and excited states of the LLL sp...

  14. How molecular should your molecular model be? On the level of molecular detail required to simulate biological networks in systems and synthetic biology.

    Science.gov (United States)

    Gonze, Didier; Abou-Jaoudé, Wassim; Ouattara, Djomangan Adama; Halloy, José

    2011-01-01

    The recent advance of genetic studies and the rapid accumulation of molecular data, together with the increasing performance of computers, led researchers to design more and more detailed mathematical models of biological systems. Many modeling approaches rely on ordinary differential equations (ODE) which are based on standard enzyme kinetics. Michaelis-Menten and Hill functions are indeed commonly used in dynamical models in systems and synthetic biology because they provide the necessary nonlinearity to make the dynamics nontrivial (i.e., limit-cycle oscillations or multistability). For most of the systems modeled, the actual molecular mechanism is unknown, and the enzyme equations should be regarded as phenomenological. In this chapter, we discuss the validity and accuracy of these approximations. In particular, we focus on the validity of the Michaelis-Menten function for open systems and on the use of Hill kinetics to describe transcription rates of regulated genes. Our discussion is illustrated by numerical simulations of prototype systems, including the Repressilator (a genetic oscillator) and the Toggle Switch model (a bistable system). We systematically compare the results obtained with the compact version (based on Michaelis-Menten and Hill functions) with its corresponding developed versions (based on "elementary" reaction steps and mass action laws). We also discuss the use of compact approaches to perform stochastic simulations (Gillespie algorithm). On the basis of these results, we argue that using compact models is suitable to model qualitatively biological systems. PMID:21187226

  15. Proposal of flexible atomic and molecular process management for Monte Carlo impurity transport code based on object oriented method

    International Nuclear Information System (INIS)

    Monte Carlo simulation code on impurity transport has been developed by several groups to be utilized mainly for fusion related edge plasmas. State of impurity particle is determined by atomic and molecular processes such as ionization, charge exchange in plasma. A lot of atomic and molecular processes have been considered because the edge plasma has not only impurity atoms, but also impurity molecules mainly related to chemical erosion of carbon materials, and their cross sections have been given experimentally and theoretically. We need to reveal which process is essential in a given edge plasma condition. Monte Carlo simulation code, which takes such various atomic and molecular processes into account, is necessary to investigate the behavior of impurity particle in plasmas. Usually, the impurity transport simulation code has been intended for some specific atomic and molecular processes so that the introduction of a new process forces complicated programming work. In order to evaluate various proposed atomic and molecular processes, a flexible management of atomic and molecular reaction should be established. We have developed the impurity transport simulation code based on object-oriented method. By employing object-oriented programming, we can handle each particle as 'object', which enfolds data and procedure function itself. A user (notice, not programmer) can define property of each particle species and the related atomic and molecular processes and then each mic and molecular processes and then each 'object' is defined by analyzing this information. According to the relation among plasma particle species, objects are connected with each other and change their state by themselves. Dynamic allocation of these objects to program memory is employed to adapt for arbitrary number of species and atomic/molecular reactions. Thus we can treat arbitrary species and process starting from, for instance, methane and acetylene. Such a software procedure would be useful also for industrial application plasmas, which enfolds more complicated atomic and molecular process such as SiH4. In this paper, a detailed description and idea to take care of arbitrary particle species and atomic/molecular process are presented based on object-oriented method. We will also demonstrate that this simulation is successful in a concrete example. (orig.)

  16. Quantum photonic base states: concept and molecular modeling. Managing chemical process descriptions beyond semi-classic schemes.

    Science.gov (United States)

    Tapia, O

    2014-02-01

    Four fundamental aspects bearing on molecular simulations are considered: (1) A different perception of quantum states; mappings from abstract Hilbert space down to laboratory levels; (2) Introduction of photon number Fock space; photonic bases tie together matter-to-photon quantum states: coherent photon-matter states. (3) Chemical tenets framed via photonic-base-states incorporating and defining multi-partite basis sets. (4) Entanglement provides a quantum-physical view connectable to a chemical bond concept. Amplitude modulations of physical quantum states realize (express) chemical change; Feshbach resonance states as a royal path to handle an equivalent to bond breaking/forming by coupling continuum-to-discrete base states. We observe that, for driving chemical processes within photonic framework, microwaves enter not only as heating sources but can act naturally in a quantum physical manner as causes for catalytic activity. PMID:24526381

  17. An overview of atomic and molecular processes in critical velocity ionization

    International Nuclear Information System (INIS)

    Alfven's critical ionization velocity (CIV) is a multi-step process involving plasma physics and plasma chemistry. The authors present an overview of the time development of some atomic and molecular processes in CIV. In the pre-onset stage, metastable states play an important role: they provide an energy pooling mechanism allowing low energy electrons to participate in the ionization processes, and help explain the low energy threshold as well as the fast time scale in the onset of CIV. For a sustaining CIV to occur, an energy requirement and Townsend's criterion have to be satisfied. The kinetic energies of the neutrals are transformed to plasma wave energies via beam-plasma instabilities, and the plasma waves heat the electrons resulting in a tail formation. A parametric domain of beam angle and neutral densities satisfying Townsend's criterion is presented

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

    CERN Document Server

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

    2014-01-01

    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...

  19. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  1. 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

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

    2013-01-01

    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...

  2. Assessing the impact of synchrotron X-ray irradiation on proteinaceous specimens at macro and molecular levels.

    Science.gov (United States)

    Moini, Mehdi; Rollman, Christopher M; Bertrand, Loïc

    2014-10-01

    Synchrotron radiation (SR) has become a preferred technique for the analysis of a wide range of archeological samples, artwork, and museum specimens. While SR is called a nondestructive technique, its effect on proteinaceous specimens has not been fully investigated at the molecular level. To investigate the molecular level effects of synchrotron X-ray on proteinaceous specimens, we propose a methodology where four variables are considered: (1) type of specimen: samples ranging from amino acids to proteinaceous objects such as silk, wool, parchment, and rabbit skin glue were irradiated; (2) synchrotron X-ray energy; (3) beam intensity; (4) irradiation time. Irradiated specimens were examined for both macroscopic and molecular effects. At macroscopic levels, color change, brittleness, and solubility enhancement were observed for several samples within 100 s of irradiation. At molecular levels, the method allowed one to quantify significant amino acid modifications. Aspartic acid (Asp), wool, parchment, and rabbit skin glue showed a significant increase in Asp racemization upon increasing irradiation time with rabbit skin glue showing the greatest increase in d-Asp formation. In contrast, Asp in silk, pure cystine (dimer of cysteine), and asparagine (Asn) did not show signs of racemization at the irradiation times studied; however, the latter two compounds showed significant signs of decomposition. Parchment and rabbit skin glue exhibited racemization of Asp, as well as racemization of isoleucine (Ile) and phenylalanine (Phe) after 100 s of irradiation with a focused beam. Under the experimental conditions and sample type and dimensions used here, more change was observed for focused and low energy (8 keV) beams than unfocused or higher energy (22 keV) beams. These results allow quantification of the change induced at the molecular level on proteinaceous specimens by synchrotron X-ray radiation and help to define accurate thresholds to minimize the probability of damage occurring to cultural heritage specimens. For most samples, damage was usually observed in the 1-10 s time scale, which is about an order of magnitude longer than SR studies of cultural heritage under X-ray fluorescence (XRF) mode; however, it is consistent with the duration of X-ray absorption spectroscopy (XAS) and microcomputed tomography (?CT) measurements. PMID:25186608

  3. Observation of the amorphous zinc oxide recrystalline process by molecular dynamics simulation

    OpenAIRE

    Lin, Ken-Huang; Sun, Shih-Jye; Ju, Shin-Pon; Tsai, Jen-Yu; Chen, Hsin-Tsung; Hsieh, Jin-Yuan

    2013-01-01

    The detailed structural variations of amorphous zinc oxide (ZnO) as well as wurtzite (B4) and zinc blende (B3) crystal structures during the temperature elevation process were observed by molecular dynamics simulation. The amorphous ZnO structure was first predicted through the simulated-annealing basin-hopping algorithm with the criterion to search for the least stable structure. The density and X-ray diffraction profiles of amorphous ZnO of the structure were in agreement with previous repo...

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

    CERN Document Server

    2013-01-01

    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.

  5. Hydrolysis and oxidation in sub- and supercritical water connecting process engineering science to molecular interactions

    Energy Technology Data Exchange (ETDEWEB)

    Tester, J.W.; Clime, J.A. [Massachusetts Inst. of Tech., Cambridge, MA (United States)

    1999-11-01

    Key engineering issues influencing the development of supercritical water oxidation for waste treatment are reviewed. Major chemical pathways and kinetics for hydrolysis and oxidation reactions of model organic wastes are discussed. In selective examples, results born extensive laboratory-scale measurements are compared with molecular simulations of solvation and reaction effects in supercritical water. Connections between reaction chemistry and observed corrosion in supercritical water oxidation processing equipment are discussed to underscore the importance of understanding electrochemical phenomena over a wide range of temperature and density conditions. Research needs for improved understanding of physical and chemical effects in supercritical fluids are identified.

  6. Overbased nonionic plus high molecular weight sulfonate waterflood additive and process of using same

    Energy Technology Data Exchange (ETDEWEB)

    Clark, C.R.; Kerfoot, O.C.; Krehbiel, D.D.

    1975-05-14

    An overbased waterflood additive consisting of a water-soluble nonionic surfactant (such as an ethoxylated alkanol) plus a water-insoluble high molecular weight hydrocarbon sulfonate having an equivalent weight of about 400 to about 600 plus an overbasing amount of a base component such as an alkali metal hydroxide, ammonium hydroxide, or an alkali metal carbonate is prepared and is injected into a petroliferous formation to improve a waterflood process. Sufficient overbasing base component is employed such that the ratio: weight of excess base component/weight of sulfonate is about 0.03 to about 5.0

  7. Characterization of skin penetration processes of organic molecules using molecular similarity and QSAR analysis.

    Science.gov (United States)

    Santos-Filho, Osvaldo A; Hopfinger, A J; Zheng, Tao

    2004-01-01

    Molecular similarity and QSAR analyses have been used to develop compact, robust, and definitive models for skin penetration by organic compounds. The QSAR models have been sought to provide an interpretation and characterization of plausible molecular mechanisms of skin penetration. A training set of 40 structurally diverse compounds were selected to be representative of a parent set of 152 compounds in terms of both structural diversity and range in measured skin penetration. The subset of 40 compounds was used in a series of QSAR analyses in the search for the most significant, compact, and straightforward skin penetration QSAR models. Molecular dynamics simulations were employed to determine a set of MI (membrane-interaction) descriptors for each test compound (solute) interacting with a model DMPC monolayer membrane model. The MI-QSAR models may capture features of cellular membrane lateral transverse transport involved in the overall skin penetration process by organic compounds. An additional set of intramolecular solute descriptors, the non-MI-QSAR descriptors, were computed and added to the trial pool of descriptors for building QSAR models. All QSAR models were constructed using multidimensional linear regression fitting and a genetic algorithm optimization function. QSAR models were constructed using only non-MI-QSAR descriptors and using a combination of both these descriptor sets. It was found that a combination of non-MI-QSAR and MI-QSAR descriptors yielded the optimum models, not only with respect to the statistical measures of fit but also regarding model predictivity. PMID:16028358

  8. MOLECULAR SIEVES AS CATALYSTS FOR METHANOL DEHYDRATION IN THE LPDMEtm PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    Andrew W. Wang

    2002-04-01

    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.

  9. RECENT PROCESS AND EQUIPMENT IMPROVEMENTS TO INCREASE HIGH LEVEL WASTE THROUGHPUT AT THE DEFENSE WASTE PROCESSING FACILITY (DWPF)

    International Nuclear Information System (INIS)

    The Savannah River Site's (SRS) Defense Waste Processing Facility (DWPF), the world's largest operating high level waste (HLW) vitrification plant, began stabilizing about 35 million gallons of SRS liquid radioactive waste by-product in 1996. The DWPF has since filled over 2000 canisters with about 4000 pounds of radioactive glass in each canister. In the past few years there have been several process and equipment improvements at the DWPF to increase the rate at which the waste can be stabilized. These improvements have either directly increased waste processing rates or have desensitized the process and therefore minimized process upsets and thus downtime. These improvements, which include glass former optimization, increased waste loading of the glass, the melter glass pump, the melter heated bellows liner, and glass surge protection software, will be discussed in this paper

  10. MZmine 2: Modular framework for processing, visualizing, and analyzing mass spectrometry-based molecular profile data

    Directory of Open Access Journals (Sweden)

    Villar-Briones Alejandro

    2010-07-01

    Full Text Available Abstract Background Mass spectrometry (MS coupled with online separation methods is commonly applied for differential and quantitative profiling of biological samples in metabolomic as well as proteomic research. Such approaches are used for systems biology, functional genomics, and biomarker discovery, among others. An ongoing challenge of these molecular profiling approaches, however, is the development of better data processing methods. Here we introduce a new generation of a popular open-source data processing toolbox, MZmine 2. Results A key concept of the MZmine 2 software design is the strict separation of core functionality and data processing modules, with emphasis on easy usability and support for high-resolution spectra processing. Data processing modules take advantage of embedded visualization tools, allowing for immediate previews of parameter settings. Newly introduced functionality includes the identification of peaks using online databases, MSn data support, improved isotope pattern support, scatter plot visualization, and a new method for peak list alignment based on the random sample consensus (RANSAC algorithm. The performance of the RANSAC alignment was evaluated using synthetic datasets as well as actual experimental data, and the results were compared to those obtained using other alignment algorithms. Conclusions MZmine 2 is freely available under a GNU GPL license and can be obtained from the project website at: http://mzmine.sourceforge.net/. The current version of MZmine 2 is suitable for processing large batches of data and has been applied to both targeted and non-targeted metabolomic analyses.

  11. From Molecular Structure to Global Processes : NMR Spectroscopy in Analytical/Environmental Chemistry

    Science.gov (United States)

    Simpson, A.

    2009-04-01

    NMR Spectroscopy is arguably the most powerful tool to elucidate structure and probe molecular interactions. A range of NMR approaches will be introduced with emphasis on addressing and understanding structure and reactivity of soil organic matter at the molecular level. The presentation will be split into three main sections. The first section will look at evidence from advanced NMR based approaches that when considered synergistically describes the major structural components in soil organic matter. Multidimensional NMR spectroscopy (1-3D NMR), automated pattern matching, spectral simulations, diffusion NMR and hybrid-diffusion NMR will be introduced in context of molecular structure. Finally the structural components in soil will be contrasted to those found in aquatic dissolved organic matter. Secondly molecular interactions of natural organic matter will be considered. Advanced structural studies have provided detailed spectral assignments which in turn permit the reactivity of various soil components to be elucidated. Aggregation and self-association of soil and dissolved organic matter will be discussed along with the structural components likely responsible for aggregation/colloid formation. Interactions of soil organic matter with anthropogenic chemicals will also be considered and NMR techniques based on "Saturation Transfer Difference" introduced. These techniques are extremely powerful and can be used to both; describe mechanistically how anthropogenic chemicals sorb to whole soils and identify the structural components (lignin, protein, cellulose, etc..) that are responsible for the binding/sorption in soil. In the last section, the "big questions" and challenges facing the field will be considered along with some novel experimental NMR based approaches that should, in future, assist in providing answers to these questions.

  12. 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

  13. Glucocorticoid-like effects of antihepatocarcinogen Rotenone are mediated via enhanced serum corticosterone levels: Molecular Fitting and Receptor Activation Studies

    Directory of Open Access Journals (Sweden)

    Badr Mostafa

    2003-01-01

    Full Text Available Abstract Background Recent studies suggest that rotenone alters cell signal transduction pathways in a manner similar to glucocorticoids. Histological and biochemical markers of glucocorticoid effects in vivo, evaluated in our laboratories, provide further evidence for similarities in the activity of glucocorticoids and rotenone. The purpose of this study was to investigate the mechanism by which rotenone produces glucocorticoid-like effects. Methods Male B6C3F1 mice were treated for 7 days with rotenone (600 ppm in diet, the glucocorticoid antagonist RU486 (2 mg/kg/day, ip, corticosterone (2 mg/kg/day, ip, or both rotenone and RU 486. Control mice received drug-free diet and the vehicle (corn oil, ip. Following preservation in 10% neutral buffered formalin, tissues were embedded in paraffin. Sections were stained with hematoxylin, eosin, and were examined by light microscopy. Tissue sections were processed for in situ enzymatic end labeling of 3'-hydroxy-DNA strand breaks, a measure of apoptosis. Corticosterone was quantified in sera, using a solid phase radioimmunoassay kit. Cells (cell line 1470.2 derived from C127 mouse mammary adenocarcinoma cells were transiently transfected with 5 ?g of pLTRLuc and 1 ?g of ?-Galactosidase expression vectors using a BTX square-wave pulser at 155 V, 4 pulses (40 ms each. Cells were then treated with dexamethasone, rotenone, or a mixture of both for 6 hr, harvested and assayed for luciferase and ?-Galactosidase activity. Using Root Mean Square (RMS fit analysis (Alchemy™, Tripose, Inc., St Louis, MO, we assessed possible structural similarities between rotenone and corticosterone, dehydrocorticosterone, glucocorticoid antagonists ZK 98.299, and RU 486. RMS fit was calculated by selecting three atoms in each of the molecules, followed by calculating the distance between these atoms. An RMS value of zero between two molecules indicates identical molecular characteristics. A positive value suggests diminished similarity with a value of 1 or higher excluding any such similarities. Results Although the stimulatory effect exerted by rotenone on hepatocellular apoptosis was in the opposite direction of that produced by the glucocorticoid antagonist RU 486, data suggested that rotenone does not directly activate the glucocorticoid receptor. Molecular fitting of rotenone to glucocorticoid receptor agonists and antagonists as well as examination of the transcriptional activation of a glucocorticoid-responsive reporter gene (Mouse MammaryTumorVirus in response to rotenone indicated that it is highly unlikely that rotenone interacts directly with the glucocorticoid receptor. However, feeding male B6C3F1 mice a diet containing rotenone (600 ppm for 7 days resulted in a 3-fold increase in serum levels of corticosterone relative to control animals. Corticosterone is the major glucocorticoid in rodents. Conclusion Rotenone does not interact directly with the glucocorticoid receptor. Elevation of serum corticosterone levels in response to rotenone may explain the glucocorticoid-like effects of this compound, and may play a role in its anti-hepatocarcinogenic effect.

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

    Science.gov (United States)

    Yu, Peiqiang

    2011-11-01

    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.

  15. 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.)

  16. Impact assessment of cadmium contamination on rice (Oryza sativa L.) seedlings at molecular and population levels using multiple biomarkers

    International Nuclear Information System (INIS)

    Full text: Assessment of environmental contamination on ecology (plant) at molecular and population levels is important in risk quantification and remediation study. Random amplified polymorphic DNA (RAPD) assay and related other fingerprinting techniques have been employed to detect the genotoxin-induced DNA damage and mutations. This research compared the effects occurring at molecular and population levels in rice seedlings exposed to cadmium (Cd) concentrations of 15 - 60 mg L-1 for eight days with quartz sand culture. Inhibition of root growth and increase of total soluble protein content in root tips of rice seedlings were observed with the increase of Cd concentration. For the RAPD analyzes, 12 RAPD primers of 50 - 70 % GC content were found to produce unique polymorphic band patterns and subsequently were used to produce a total of 180 bands of 179 ? 3056 bp in molecular size in the control root tips of rice seedlings. Results produced by these RAPD primers indicate that changes in RAPD profiles of root tips after Cd treatment include modifications in band intensity and gain or loss of bands by comparison with control. The effect of changes was dose-dependent. Genomic template stability compares favourably with the traditional indices such as root growth and soluble protein content. The DNA polymorphisms detected by RAPD analysis can be applied as a suitable biomarker assay for the detection of genotoxic effects of Cd contamination on plants. (autects of Cd contamination on plants. (author)

  17. Tank waste remediation system phase I high-level waste feed processability assessment report

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, S.L.; Stegen, G.E., Westinghouse Hanford

    1996-08-01

    This report evaluates the effects of feed composition on the Phase I high-level waste immobilization process and interim storage facility requirements for the high-level waste glass.Several different Phase I staging (retrieval, blending, and pretreatment) scenarios were used to generate example feed compositions for glass formulations, testing, and glass sensitivity analysis. Glass models and data form laboratory glass studies were used to estimate achievable waste loading and corresponding glass volumes for various Phase I feeds. Key issues related to feed process ability, feed composition, uncertainty, and immobilization process technology are identified for future consideration in other tank waste disposal program activities.

  18. The Weibull manifold in low-level image processing: an application to automatic image focusing.

    OpenAIRE

    Zografos, Vasileios; Lenz, Reiner; Felsberg, Michael

    2013-01-01

    In this paper, we introduce a novel framework for low-level image processing and analysis. First, we process images with very simple, difference-based filter functions. Second, we fit the 2-parameter Weibull distribution to the filtered output. This maps each image to the 2D Weibull manifold. Third, we exploit the information geometry of this manifold and solve low-level image processing tasks as minimisation problems on point sets. For a proof-of-concept example, we examine the image autofoc...

  19. MILLIMETER-SCALE GENETIC GRADIENTS AND COMMUNITY-LEVEL MOLECULAR CONVERGENCE IN A HYPERSALINE MICROBIAL MAT

    Energy Technology Data Exchange (ETDEWEB)

    Fenner, Marsha W; Kunin, Victor; Raes, Jeroen; Harris, J. Kirk; Spear, John R.; Walker, Jeffrey J.; Ivanova, Natalia; Mering, Christian von; Bebout, Brad M.; Pace, Norman R.; Bork, Peer; Hugenholtz, Philip

    2008-04-30

    To investigate the extent of genetic stratification in structured microbial communities, we compared the metagenomes of 10 successive layers of a phylogenetically complex hypersaline mat from Guerrero Negro, Mexico. We found pronounced millimeter-scale genetic gradients that are consistent with the physicochemical profile of the mat. Despite these gradients, all layers displayed near identical and acid-shifted isoelectric point profiles due to a molecular convergence of amino acid usage indicating that hypersalinity enforces an overriding selective pressure on the mat community.

  20. Dynamics of cooperative emissions in a cascade three-level molecular system driven by an ultrashort laser pulse

    International Nuclear Information System (INIS)

    This paper investigates the dynamics of cooperative emissions in a cascade three-level system driven by an ultrashort laser pulse by solving numerically the full-wave Maxwell–Bloch equations. The 4, 4'-bis(dimethylamino) stilbene molecule is used as the model molecule because of its strong two-photon absorption property. The two-colour cooperative emissions are studied as functions of molecular number density and dephasing rate of the dipole coherence. The propagation effects on the evolution of the cooperative radiations are also taken into account. The cooperative radiations are enhanced for large number density of the molecule, while the fast dephasing of the dipole coherence reduces the intensity of the cooperative radiations and delays the emission times or even inhibits the formation of the emissions. The delay time of the radiation decreases with the increase of the molecular number density and the propagation distance. (classical areas of phenomenology)

  1. 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

  2. Femtosecond laser processing of germanium: an ab initio molecular dynamics study

    International Nuclear Information System (INIS)

    An ab initio molecular dynamics study of femtosecond laser processing of germanium is presented in this paper. The method based on the finite temperature density functional theory is adopted to probe the structural change, thermal motion of the atoms, dynamic property of the velocity autocorrelation, and the vibrational density of states. Starting from a cubic system at room temperature (300 K) containing 64 germanium atoms with an ordered arrangement of 1.132 nm in each dimension, the femtosecond laser processing is simulated by applying a Nosé–Hoover thermostat to the electronic subsystem for ?100 fs and continuing with a microcanonical ensemble simulation of ?200 fs. The simulation results show solid, liquid and gas phases of germanium under adjusted intensities of the femtosecond laser irradiation. We find that the irradiated germanium is distinguishable from the usual germanium crystal by analysing their melting and dynamic properties. (paper)

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

    Science.gov (United States)

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

    2014-01-01

    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

  4. A flexible approach for early production of high-level waste glass: A process canister

    International Nuclear Information System (INIS)

    A process canister, which has several advantages, is being considered for use at the West Valley Demonstration Project. The plan is to cast an acceptable high-level waste glass in process canisters. These canisters are low-cost molds which are suitable for casting the high-level waste glass in the production plant and for storing on-site. Before shipping to a federal repository, the processing canisters could be packaged in approved repository disposal canisters. This approach would allow the Project to fix the design of the process equipment and facility at an early stage while providing the flexibility of meeting disposal canister acceptance criteria that are not yet final. Due to the unique nature of the West Valley Demonstration Project, the process canisters appear to provide a simple, yet efficient, way for providing a waste package with uncontaminated exterior surfaces for interim storage before shipping to the repository

  5. Cilnidipine regulates glucose metabolism and levels of high-molecular adiponectin in diet-induced obese mice.

    Science.gov (United States)

    Ueno, Daisuke; Masaki, Takayuki; Gotoh, Koto; Chiba, Seiichi; Kakuma, Tetsuya; Yoshimatsu, Hironobu

    2013-03-01

    The aim of the present study is to examine the effects of the antihypertensive drug cilnidipine on glucose metabolism and adipocytokines, including adiponectin, in diet-induced obese (DIO) mice. The effects of cilnidipine on insulin sensitivity and the levels of adiponectin in DIO mice were examined after the mice had been treated with cilnidipine dissolved in water at a dose of 0.2?g?l(-1) for 14 days. As expected, treatment with cilnidipine decreased the systolic and diastolic blood pressures in DIO mice, compared with control mice (PCilnidipine treatment improved glucose and insulin sensitivity in DIO mice. In addition, cilnidipine treatment dramatically increased the level of adiponectin in white adipose tissue (Pcilnidipine treatment. Finally, the secretion of adiponectin from adipocytes was increased after cilnidipine treatment. Taken together, these results indicate that cilnidipine improves insulin tolerance and adiponectin levels, especially high-molecular type adiponectin, in DIO mice. PMID:23051658

  6. 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

  7. Mercury reduction and removal during high-level radioactive waste processing and vitrification

    International Nuclear Information System (INIS)

    A reference process for immobilizing the high-level radioactive waste in borosilicate glass has been developed at the Savannah River Plant. This waste contains a substantial amount of mercury from separations processing. Because mercury will not remain in borosilicate glass at the processing temperature, mercury must be removed before vitrification or must be handled in the off-gas system. A process has been developed to remove mercury by reduction with formic acid prior to vitrification. Additional benefits of formic acid treatment include improved sludge handling and glass melter redox control

  8. 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

  9. Field-dependent magnetic parameters in {Ni4Mo12}: Magnetostriction at the molecular level?

    CERN Document Server

    Schnack, J; Luban, M; Koegerler, P; Morosan, E; Fuchs, R; Modler, R; Nojiri, H; Rai, R C; Cao, J; Musfeldt, J L; Xing Wei; Nojiri, Hiroyuki; Rai, Ram C.; Cao, Jinbo

    2006-01-01

    We investigate the bulk magnetic, electron paramagnetic resonance, and magneto-optical properties of {Ni4Mo12}, a magnetic molecule with antiferromagnetically coupled tetrahedral {Ni4Mo12} in a diamagnetic molybdenum matrix. The low-temperature magnetization exhibits steps at irregular field intervals, a result that cannot be explained using a Heisenberg model even if it is augmented by magnetic anisotropy and biquadratic terms. Allowing the exchange and anisotropy parameters to depend on the magnetic field provides the best fit to our data, suggesting that the molecular structure (and thus the interactions between spins) may be changing with applied magnetic field.

  10. Recent Process and Equipment Improvements to Increase High Level Waste Throughput at The Defense Waste Processing Facility (DWPF)

    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 an 8 % waste throughput increase over the standard 28 % waste loading based upon operational efficiencies. Improvements in canister production include the pour spout heated bellows liner (7 %), 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 14 %. 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 re transformer bus bar cooling water leak repair and new Infra-red camera for determination of glass height in the canister are discussed. (authors)

  11. An optimal retrieval, processing, and blending strategy for immobilization of Hanford high-level tank waste

    International Nuclear Information System (INIS)

    Hanford tank waste will be separated into high-level and low-level portions; each portion will then be vitrified (other waste forms are also being considered for low-level waste) to produce a stable glass form for disposal. Because of the wide variability in the tank waste compositions, blending is being considered as a way to reduce the number of distinct compositions that must be vitrified and to minimize the resultant volume of vitrified waste. Three years of computational glass formulation and blending studies have demonstrated that blending of the high-level waste before vitrification can reduce the volume of high-level waste glass required by as much as 50 percent. This level of reduction would be obtained if all the high-level waste were blended together (Total Blend) prior to vitrification, requiring the retrieval and pretreatment of all tank waste before high-level vitrification was started. This paper will present an overall processing strategy that should be able to match the blending performance of the Total Blend and be more logistically feasible. The strategy includes retrieving, pretreating, blending and vitrifying Hanford tank waste. This strategy utilizes blending both before and after pretreatment. Similar wastes are blended before pretreatment, so as not to dilute species targeted for removal. The high-level portions of these pretreated early blends are then selectively blended to produce a small number of high-level vitrification feed streamsigh-level vitrification feed streams

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

    Science.gov (United States)

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

    2014-08-01

    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

  13. 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

  14. Gene Expression Profiles of the NCI-60 Human Tumor Cell Lines Define Molecular Interaction Networks Governing Cell Migration Processes

    OpenAIRE

    Kohn, Kurt W.; Zeeberg, Barry R; Reinhold, William C.; Sunshine, Margot; Luna, Augustin; POMMIER, Yves

    2012-01-01

    Although there is extensive information on gene expression and molecular interactions in various cell types, integrating those data in a functionally coherent manner remains challenging. This study explores the premise that genes whose expression at the mRNA level is correlated over diverse cell lines are likely to function together in a network of molecular interactions. We previously derived expression-correlated gene clusters from the database of the NCI-60 human tumor cell lines and assoc...

  15. Endogenous testosterone levels are associated with neural activity in men with schizophrenia during facial emotion processing.

    Science.gov (United States)

    Ji, Ellen; Weickert, Cynthia Shannon; Lenroot, Rhoshel; Catts, Stanley V; Vercammen, Ans; White, Christopher; Gur, Raquel E; Weickert, Thomas W

    2015-06-01

    Growing evidence suggests that testosterone may play a role in the pathophysiology of schizophrenia given that testosterone has been linked to cognition and negative symptoms in schizophrenia. Here, we determine the extent to which serum testosterone levels are related to neural activity in affective processing circuitry in men with schizophrenia. Functional magnetic resonance imaging was used to measure blood-oxygen-level-dependent signal changes as 32 healthy controls and 26 people with schizophrenia performed a facial emotion identification task. Whole brain analyses were performed to determine regions of differential activity between groups during processing of angry versus non-threatening faces. A follow-up ROI analysis using a regression model in a subset of 16 healthy men and 16 men with schizophrenia was used to determine the extent to which serum testosterone levels were related to neural activity. Healthy controls displayed significantly greater activation than people with schizophrenia in the left inferior frontal gyrus (IFG). There was no significant difference in circulating testosterone levels between healthy men and men with schizophrenia. Regression analyses between activation in the IFG and circulating testosterone levels revealed a significant positive correlation in men with schizophrenia (r=.63, p=.01) and no significant relationship in healthy men. This study provides the first evidence that circulating serum testosterone levels are related to IFG activation during emotion face processing in men with schizophrenia but not in healthy men, which suggests that testosterone levels modulate neural processes relevant to facial emotion processing that may interfere with social functioning in men with schizophrenia. PMID:25796490

  16. Framework for sustainability assessment of industrial processes with multi-scale technology at design level: microcapsules production process

    OpenAIRE

    Navarro Rosa, Jennifer

    2009-01-01

    In a world with limited resources and serious environmental, social and economical impacts, a more sustainable life style is everyday more important. Therefore, the general objective of this work is to develop a methodological procedure for eco-efficiency and sustainability assessment of industrial processes with multi-scale technology at design level. The methodology developed follows the ISO 14040 series for environmental LCA standard. To integrate the three pillars of sustainability the an...

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

    Science.gov (United States)

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

    2015-02-16

    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

  18. Donut-shaped chambers for analysis of biochemical processes at the cellular and subcellular levels.

    Science.gov (United States)

    Zurgil, N; Ravid-Hermesh, O; Shafran, Y; Howitz, S; Afrimzon, E; Sobolev, M; He, J; Shinar, E; Goldman-Levi, R; Deutsch, M

    2014-07-01

    In order to study cell-cell variation with respect to enzymatic activity, individual live cell analysis should be complemented by measurement of single cell content in a biomimetic environment on a cellular scale arrangement. This is a challenging endeavor due to the small volume of a single cell, the low number of target molecules and cell motility. Micro-arrayed donut-shaped chambers (DSCs) of femtoliter (fL), picoliter (pL), and nanoliter (nL) volumes have been developed and produced for the analysis of biochemical reaction at the molecular, cellular and multicellular levels, respectively. DSCs are micro-arrayed, miniature vessels, in which each chamber acts as an individual isolated reaction compartment. Individual live cells can settle in the pL and nL DSCs, share the same space and be monitored under the microscope in a noninvasive, time-resolved manner. Following cell lysis and chamber sealing, invasive kinetic measurement based on cell content is achieved for the same individual cells. The fL chambers are used for the analysis of the same enzyme reaction at the molecular level. The various DSCs were used in this proof-of-principle work to analyze the reaction of intracellular esterase in both primary and cell line immune cell populations. These unique DSC arrays are easy to manufacture and offer an inexpensive and simple operating system for biochemical reaction measurement of numerous single cells used in various practical applications. PMID:24829933

  19. Single-walled carbon nanotube bucky paper/epoxy composites: Molecular dynamics simulation and process development

    Science.gov (United States)

    Gou, Jihua

    The discovery of carbon nanotubes by Iijima in 1991 has initiated a large number of scientific investigations to explore their unique properties and potential applications. One of the major applications is nanocomposites with nanotubes as the reinforcing material. Currently, nanotube composites are fabricated by using the direct mixing technique. However, this technique is limited by low weight fraction of nanotubes and uncontrollable nanostructures in the composite. This dissertation research presents a new nanocomposite processing method in which single-walled nanotubes (SWNTs) are first preformed into nanotube bucky papers (NBPs) and then liquid epoxy resins are infiltrated through the NBPs and cured to fabricate the composite. The major technical challenges for developing the NBP/Epoxy nanocomposite include (1) understanding of the molecular interactions between nanotubes and epoxy resin at the nanometer scale; (2) fabricating NBPs with uniform nano-scaled rope size and pore size; and (3) realizing resin infiltration through the nanoporous structure of NBPs. Molecular dynamics (MD) simulations were used to examine the important molecular interactions, including affinity and interfacial bonding. The affinities of two kinds of epoxy systems were examined. Unlike the DGEBA/DETA epoxy system, both EPON 862 epoxy resin and DETDA molecules had good affinities with SWNT and were chosen as the matrix material in the nanocomposites. Pullout simulations of a SWNT from cured epoxy resins were performed to investigate the stress transfer potential of the SWNT/Epoxy interface. The estimated interfacial shear stress is up to 75 MPa. The MD simulation results were found useful to guide the process development and property prediction of NBP/Epoxy nanocomposites. Experimentally, the fabrication process for NBPs was analyzed and optimized using the design of experiments (DOE) approach. The SEM and AFM image analyses of the resultant nanocomposites indicated observable wetting and bonding between nanotubes and the epoxy resin. The dynamics mechanic analysis (DMA) showed that a 200--250% increase of the storage modulus was achieved in the nanocomposites. This research is the first attempt to make nanocomposites using nanotube bucky papers.

  20. 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

  1. A Proof of Factorization Theorem of Drell-Yan Process at Operator Level

    CERN Document Server

    Zhou, Gao-Liang

    2013-01-01

    An alternative proof of factorization theorem for Drell-Yan process that works at operator level is given in the article. Final state interactions for such inclusive processes are proved to be cancel out at operator level according to the unitarity of time evolution operator. After this cancellation, one can always deform the integral path so that eikonal line approximation works while calculating the time evolution of electromagnetic currants. Decoupling of soft gluons from collinear jets is realized by defining new collinear fields that decouple from soft gluons. Cancelation of soft gluons is attribute to unitarity of time evolution operator and light-like Wilson lines of soft gluons.

  2. Correlation test to assess low-level processing of high-density oligonucleotide microarray data

    Directory of Open Access Journals (Sweden)

    Bergh Jonas

    2005-03-01

    Full Text Available Abstract Background There are currently a number of competing techniques for low-level processing of oligonucleotide array data. The choice of technique has a profound effect on subsequent statistical analyses, but there is no method to assess whether a particular technique is appropriate for a specific data set, without reference to external data. Results We analyzed coregulation between genes in order to detect insufficient normalization between arrays, where coregulation is measured in terms of statistical correlation. In a large collection of genes, a random pair of genes should have on average zero correlation, hence allowing a correlation test. For all data sets that we evaluated, and the three most commonly used low-level processing procedures including MAS5, RMA and MBEI, the housekeeping-gene normalization failed the test. For a real clinical data set, RMA and MBEI showed significant correlation for absent genes. We also found that a second round of normalization on the probe set level improved normalization significantly throughout. Conclusion Previous evaluation of low-level processing in the literature has been limited to artificial spike-in and mixture data sets. In the absence of a known gold-standard, the correlation criterion allows us to assess the appropriateness of low-level processing of a specific data set and the success of normalization for subsets of genes.

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

    OpenAIRE

    Wan, EW; Agrawal, N

    2009-01-01

    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...

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

    Science.gov (United States)

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

    2014-12-01

    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.

  5. ATOMIC AND MOLECULAR PHYSICS: Kinetic theory of (2 + 4)-level atom in ?+ - ?- laser fields

    Science.gov (United States)

    Yu, Chuang; Yu, De-Shui; Chen, Jing-Biao

    2009-08-01

    The kinetic theory of (2 + 4)-level atoms in ? + - ?- laser fields is presented. We systemically discuss friction coefficient, momentum diffusion tensor and atomic temperature based on the Fokker-Planck equation. This cooling system is much like that of a (1 + 3)-level atom, and the temperature is still limited to the Doppler temperature. Since this cooling system has not been investigated before, this work may be regarded as a necessary complement to the laser cooling theory.

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

    OpenAIRE

    Mercado, Charles P.; Kilic, Fusun

    2010-01-01

    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 ...

  7. Tannin signatures of barks, needles, leaves, cones, and wood at the molecular level

    Science.gov (United States)

    Hernes, Peter J.; Hedges, John I.

    2004-03-01

    We analyzed 117 tissues from 77 different plant species for molecular tannin. Tannin was measured in 89 tissues (as high as 10.5 wt.% total tannin), including procyanidin (PC) tannin in 88 tissues, prodelphinidin (PD) tannin in 50, and propelargonidin (PP) tannin in 24. In addition to tannin, several flavones, flavanones, and triterpenoids were measured, the latter which yielded as much as 4.5 wt.%. Compositions varied considerably between species, including several that yielded comparatively rare tannin or triterpenoids. Conifer needles were distinguished by high yields of PD tannin overall and relative to PC tannin. Dicotyledon leaves were characterized by the presence of flavones and triterpenoids. Barks were marked by flavanones and tetracosanoic acid. Based on these trends, relationships that could be useful as geochemical parameters were developed for distinguishing needles, leaves, and barks as possible components of litter, soil, or sedimentary mixtures.

  8. Levels of participation and interactional issue framing in a water area planning process

    OpenAIRE

    Francois, G.; Dewulf, A.; Taillieu, T.

    2008-01-01

    Session 1-2 Levels of participation and their impact on interactional issue framing in a water area planning process Greet François 1, Art Dewulf 2, Tharsi Taillieu 1 1 K.U.Leuven - Research group for Work, Organisational and Personnel Psychology 2 Wageningen University - Public Administration and Policy Group This paper is an analysis of a participatory process to define a water management plan for the area between the Kromme Rijn and the Amsterdam-Rijn canal in The Netherlands. The waterbo...

  9. Quantum computation and the physical computation level of biological information processing

    OpenAIRE

    Castagnoli, Giuseppe

    2009-01-01

    On the basis of introspective analysis, we establish a crucial requirement for the physical computation basis of consciousness: it should allow processing a significant amount of information together at the same time. Classical computation does not satisfy the requirement. At the fundamental physical level, it is a network of two body interactions, each the input-output transformation of a universal Boolean gate. Thus, it cannot process together at the same time more than th...

  10. Product and Process Innovation and the Decision to Export: Firm-level Evidence for Belgium

    OpenAIRE

    Van Beveren, Ilke; Vandenbussche, Hylke

    2009-01-01

    Using data from the Community Innovation Survey for Belgium in two consecutive periods, this paper explores the relationship between firm-level innovation activities and the propensity to start exporting. To measure innovation, we include indicators of both innovative effort (R&D activities) as well as innovative output (product and process innovation). Our results suggest that the combination of product and process innovation, rather than either of the two in isolation, increases a firm's pr...

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

    OpenAIRE

    Jakopin, Nives

    2011-01-01

    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...

  12. Natural Language Processing Technologies for Multi-Level Intelligent Spam Mail-Filter

    OpenAIRE

    Haiyan; Xiaojiao

    2014-01-01

    To overcome the lack of existing mail filtering system, we designed a content-based message filtering system of multi-level intelligence. Using natural language processing technology, it denotes the E-mail content including attachments. First, it pre-processes the content of E-mail, including segmentation, feature extraction. Second, combining knowledge-base and expansion of the feature, it can form the vector. Corresponding categories vector in the database, two vectors similar degree of cal...

  13. A review of alternative wasteforms and processes for future solidification of high-level liquid wastes

    International Nuclear Information System (INIS)

    A catalogue of alternative wasteforms proposed for the solidification of high-level liquid wastes has been compiled, together with an appraisal of their suitability for longer-term future UK waste immobilisation. The properties of the more promising alternatives have been critically reviewed, and an attempt has been made to ascertain the feasibility of their manufacture under realistic process conditions. The analysis suggests that the alternative wasteforms/processes showing most potential for future development are the durable glasses and SYNROC. (author)

  14. Emotional face processing in women with high and low levels of eating disorder related symptoms.

    OpenAIRE

    Jones, L.; Harmer, C.; Cowen, P.; Cooper, M.

    2008-01-01

    OBJECTIVES: Emotional processing has rarely been investigated in those "at risk" of developing an eating disorder. This study investigated the processing of six basic emotions depicted on faces in an "at risk" group, compared to a control group. DESIGN: Participants were women with high (N=29) and low (N=23) levels of eating disorder symptoms who were not taking psychotropic medication. A well characterised computerised task (Facial Expression Emotion Task) was administered to all participant...

  15. Assessment of surface contamination level in an operating uranium ore processing facility of Jaduguda, India

    International Nuclear Information System (INIS)

    Radiological concern of the occupational workers and the area is given priority over other safety issue in confirmation with the stipulated guideline of national regulatory agency (AERB/FEFCF/SG-2, 2007). The key concern from the radiological hazard evaluation point of view is air activity, external gamma level and surface contamination. Present investigations was carried out to ascertain the surface contamination level of uranium ore processing facility at Jaduguda, Jharkhand. For a low grade uranium ore processing industry surface contamination is a major concern in product precipitation and recovery section. In view of this, the ore processing plant can broadly be classified into three areas i.e. ion exchange area, precipitation and product recovery section and other areas. The monitoring results incorporate the level of surface contamination of the plant during the last five years. The geometric mean activity of surface contamination level was 31.1, 34.5 and 9.8 Bq dm-2 in ion exchange, product precipitation and recovery and other areas with GSD of 2, 2.5 and 1.9. In most of the cases the surface contamination level was well within the recommended limit of 100 Bq dm-2 for M class uranium compound. Occasional cases of surface contamination levels exceeding the recommended limit were addressed and areas were decontaminated. Based on the study, modification in the design feature of the surface of the finished product section was also suggested so that the decontamination procedure can be more effectively implemented

  16. Study of a hydrogen-bombardment process for molecular cross-linking within thin films

    International Nuclear Information System (INIS)

    A low-energy hydrogen bombardment method, without using any chemical additives, has been designed for fine tuning both physical and chemical properties of molecular thin films through selectively cleaving C-H bonds and keeping other bonds intact. In the hydrogen bombardment process, carbon radicals are generated during collisions between C-H bonds and hydrogen molecules carrying ?10 eV kinetic energy. These carbon radicals induce cross-linking of neighboring molecular chains. In this work, we focus on the effect of hydrogen bombardment on dotriacontane (C32H66) thin films as growing on native SiO2 surfaces. After the hydrogen bombardment, XPS results indirectly explain that cross-linking has occurred among C32H66 molecules, where the major chemical elements have been preserved even though the bombarded thin film is washed by organic solution such as hexane. AFM results show the height of the perpendicular phase in the thin film decreases due to the bombardment. Intriguingly, Young's modulus of the bombarded thin films can be increased up to ?6.5 GPa, about five times of elasticity of the virgin films. The surface roughness of the thin films can be kept as smooth as the virgin film surface after thorough bombardment. Therefore, the hydrogen bombardment method shows a great potential in the modification of morphological, mechanical, and tribological properties of organic thin films for a broad range of applicatin films for a broad range of applications, especially in an aggressive environment.

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

    CERN Document Server

    Maestri, Matteo; 10.1016/j.ces.2012.02.043

    2012-01-01

    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) mechanism. The obtained results furthermore underscore the danger of common first-principles analyses that focus on a priori selected dominant paths. Not restricted to such bias, our herein proposed hierarchical approach thus constitutes a promising avenue to properly transport and incorporate the ab initio predictive-quality to a new level of system complexity.

  18. 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)

  19. Low temperature conversion of molecular species via a hybrid plasma discharge -- catalytic process

    Science.gov (United States)

    Barnat, Ed

    2008-10-01

    Various avenues are being perused towards developing more sustainable energy sources to meet current and future energy requirements. Central to these energy surety related concerns is the efficiency of a given processes (chemical reaction) employed for synthesis of these fuels or energy sources. We present results from our preliminary studies on using low-temperature non-equilibrium discharges, coupled to active surfaces as a means of efficiently dissociating key molecular species that may be used towards fuel synthesis. Specifically, we focus on dissociating carbon dioxide to form carbon monoxide which is used in conjunction with hydrogen to generate syngas and higher hydrocarbons. While studies have been performed using various plasma sources, we primarily use a ``hybrid'' plasmas with tuned E/N that has been demonstrated to efficiently dissociate carbon dioxide[1]. [1] S. N. Andreev et. al, Spectrochimica Acta A 60, 3361 (2004).

  20. Molecular dynamics simulations of atomic assembly in the process of GaN film growth

    International Nuclear Information System (INIS)

    Molecular dynamics simulations using a Coulomb-Buckingham potential have been used to investigate the process of wurtzite GaN films growth, including the appearance of films in early stage, regulation of growth, structure of the surface and the dynamic features. The simulations show that the N atoms and Ga atoms are absorbed on the lattice of substrate and take on a distinct sandwich structure. Time evolution of the mean square displacements and diffusion coefficient of the deposited atoms are observed, the results show that the clusters will become stable with the increase of time steps and the atoms reach the initial stable state after 25 ps; N atoms reach the equilibrium positions more quickly than Ga atoms. It is proved by radial distribution function and the ratio of vacancy of every deposited layer that the crystalline characters of the films will become better as the time steps increase and weaker from bottom to top.

  1. Electron spin resonance studies on reduction process of nitroxyl spin radicals used in molecular imaging

    International Nuclear Information System (INIS)

    The Electron spin resonance studies on the reduction process of nitroxyl spin probes were carried out for 1mM 14N labeled nitroxyl radicals in pure water and 1 mM concentration of ascorbic acid as a function of time. The electron spin resonance parameters such as signal intensity ratio, line width, g-value, hyperfine coupling constant and rotational correlation time were determined. The half life time was estimated for 1mM 14N labeled nitroxyl radicals in 1 mM concentration of ascorbic acid. The ESR study reveals that the TEMPONE has narrowest line width and fast tumbling motion compared with TEMPO and TEMPOL. From the results, TEMPONE has long half life time and high stability compared with TEMPO and TEMPOL radical. Therefore, this study reveals that the TEMPONE radical can act as a good redox sensitive spin probe for molecular imaging

  2. A domain decomposition parallel processing algorithm for molecular dynamics simulations of polymers

    Science.gov (United States)

    Brown, David; Clarke, Julian H. R.; Okuda, Motoi; Yamazaki, Takao

    1994-10-01

    We describe in this paper a domain decomposition molecular dynamics algorithm for use on distributed memory parallel computers which is capable of handling systems containing rigid bond constraints and three- and four-body potentials as well as non-bonded potentials. The algorithm has been successfully implemented on the Fujitsu 1024 processor element AP1000 machine. The performance has been compared with and benchmarked against the alternative cloning method of parallel processing [D. Brown, J.H.R. Clarke, M. Okuda and T. Yamazaki, J. Chem. Phys., 100 (1994) 1684] and results obtained using other scalar and vector machines. Two parallel versions of the SHAKE algorithm, which solves the bond length constraints problem, have been compared with regard to optimising the performance of this procedure.

  3. Auger electrons - A nano-probe for structural, molecular and cellular processes

    International Nuclear Information System (INIS)

    This paper provides a brief review of recently published work on biophysical and biological aspects of Auger processes. Three specific questions have been considered. (1) Does charge neutralisation contribute to molecular damage such as DNA strand breaks? (2) How many DNA double strand breaks are produced by a single decay of DNA bound 125I? (3) What is the correlation between number of ?H2AX foci and number of double strand breaks (DSB)? The paper also gives preliminary reports on two new calculations: (a) calculation of the spectrum of Auger electrons released during decay of 124I and (b) the use of Auger electrons in the decay of 125I as a probing agent of novel DNA structures. (authors)

  4. Molecular dynamics simulation of surface deformation via Ar+ ion collision process

    International Nuclear Information System (INIS)

    We have carried out molecular dynamics (MD) simulations of 50 keV accelerated Ar ions, colliding with a Si surface. Using this procedure the amorphous structural region of the Si was found to expand with the progression of the interface region, that lie between the amorphous structure and the crystalline structure, as fluence increased in the depth direction. There has been considerable interest in studying the time development of the behavior of sputtered silicon atoms after being subjected to collisions with the Ar ions. Here, by tracking the atoms in the computational domain, clusters formed during sputtering are classified under various kinds. In this process small cluster of atoms e.g., monomer and dimer, and large cluster of atoms in forms of hillocks are formed where the smaller cluster have their energy higher than that of the large cluster.

  5. Intrinsic bacterial biodegradation of petroleum contamination demonstrated in situ using natural abundance, molecular-level 14C analysis

    International Nuclear Information System (INIS)

    Natural abundance, molecular-level C14 analysis was combined with comprehensive gas chromatography (GC x GC) to investigate, in situ, the role of intrinsic biodegradation in the loss of petroleum hydrocarbons from the rocky, inter-tidal zone impacted by the Bouchard 120 oil spill. GC x GC analysis indicated accelerated losses of n-alkane components of the residual petroleum hydrocarbons between day 40 and day 50 after the spill. 14C analysis of bacterial phospholipid fatty acids (PLFA) from the impacted zone on day 44 showed that the polyunsaturated fatty acids attributed to the photoautotrophic component of the microbial community had the same (14C as the local dissolved inorganic carbon (DIG), indicating that this DIG was their carbon source. In contrast there was significant (C depletion in the saturated and mono-unsaturated PLFA indicating incorporation of petroleum carbon. This correlation between the observed accelerated n-alkane losses and microbial incorporation of (C-depleted carbon directly demonstrated, in situ, that intrinsic biodegradation was affecting the petroleum. Since the majority of organic contaminants originate from petroleum feed-stocks, in situ molecular-level 14C analysis of microbial PLFA can provide insights into the occurrence and pathways of biodegradation of a wide range of organic contaminants. (Author)

  6. Accurate vibrational spectra via molecular tailoring approach: A case study of water clusters at MP2 level

    Science.gov (United States)

    Sahu, Nityananda; Gadre, Shridhar R.

    2015-01-01

    In spite of the recent advents in parallel algorithms and computer hardware, high-level calculation of vibrational spectra of large molecules is still an uphill task. To overcome this, significant effort has been devoted to the development of new algorithms based on fragmentation methods. The present work provides the details of an efficient and accurate procedure for computing the vibrational spectra of large clusters employing molecular tailoring approach (MTA). The errors in the Hessian matrix elements and dipole derivatives arising due to the approximation nature of MTA are reduced by grafting the corrections from a smaller basis set. The algorithm has been tested out for obtaining vibrational spectra of neutral and charged water clusters at Møller-Plesset second order level of theory, and benchmarking them against the respective full calculation (FC) and/or experimental results. For (H2O)16 clusters, the estimated vibrational frequencies are found to differ by a maximum of 2 cm-1 with reference to the corresponding FC values. Unlike the FC, the MTA-based calculations including grafting procedure can be performed on a limited hardware, yet take a fraction of the FC time. The present methodology, thus, opens a possibility of the accurate estimation of the vibrational spectra of large molecular systems, which is otherwise impossible or formidable.

  7. Accurate vibrational spectra via molecular tailoring approach: a case study of water clusters at MP2 level.

    Science.gov (United States)

    Sahu, Nityananda; Gadre, Shridhar R

    2015-01-01

    In spite of the recent advents in parallel algorithms and computer hardware, high-level calculation of vibrational spectra of large molecules is still an uphill task. To overcome this, significant effort has been devoted to the development of new algorithms based on fragmentation methods. The present work provides the details of an efficient and accurate procedure for computing the vibrational spectra of large clusters employing molecular tailoring approach (MTA). The errors in the Hessian matrix elements and dipole derivatives arising due to the approximation nature of MTA are reduced by grafting the corrections from a smaller basis set. The algorithm has been tested out for obtaining vibrational spectra of neutral and charged water clusters at Møller-Plesset second order level of theory, and benchmarking them against the respective full calculation (FC) and/or experimental results. For (H2O)16 clusters, the estimated vibrational frequencies are found to differ by a maximum of 2 cm(-1) with reference to the corresponding FC values. Unlike the FC, the MTA-based calculations including grafting procedure can be performed on a limited hardware, yet take a fraction of the FC time. The present methodology, thus, opens a possibility of the accurate estimation of the vibrational spectra of large molecular systems, which is otherwise impossible or formidable. PMID:25573553

  8. Study of crater formation and sputtering process with large gas cluster impact by molecular dynamics simulations

    International Nuclear Information System (INIS)

    Molecular dynamics (MD) simulations of large argon clusters impacting on silicon solid targets were performed in order to study the transient process of crater formation and sputtering. The MD simulations demonstrate that the initial momentum of incident cluster is transferred to target surface atoms through multiple collision mechanism, where the initial momentum, which is along to the surface normal before impact, is deflected to lateral direction. This momentum transfer process was analyzed by the calculation of the velocity at the crater edge (the interface between cluster and target). In the case of Ar1000 cluster impact on Si(1 0 0) target at low energy per atom less than 40 eV/atom, the maximum value of lateral velocity of the crater edge increases in proportional to the velocity of incident cluster atoms. On the other hand, the crater edge velocity saturates over 40 eV/atom of incident energy per atom. In this case, the whole of constituent cluster atoms are implanted into the target and expand in both lateral and reflective directions at the subsurface region of the target. These MD simulations demonstrated that this collisional process result in the high yield sputtering of the target atoms.

  9. Shocks in dense clouds. IV. Effects of grain-grain processing on molecular line emission

    CERN Document Server

    Anderl, S; Forêts, G Pineau des; Flower, D R

    2014-01-01

    Grain-grain processing has been shown to be an indispensable ingredient of shock modelling in high density environments. For densities higher than \\sim10^5 cm-3, shattering becomes a self-enhanced process that imposes severe chemical and dynamical consequences on the shock characteristics. Shattering is accompanied by the vaporization of grains, which can directly release SiO to the gas phase. Given that SiO rotational line radiation is used as a major tracer of shocks in dense clouds, it is crucial to understand the influence of vaporization on SiO line emission. We have developed a recipe for implementing the effects of shattering and vaporization into a 2-fluid shock model, resulting in a reduction of computation time by a factor \\sim100 compared to a multi-fluid modelling approach. This implementation was combined with an LVG-based modelling of molecular line radiation transport. Using this model we calculated grids of shock models to explore the consequences of different dust-processing scenarios. Grain-...

  10. Description of Cognitive and Competence Processes Involved in the Levels of Reading Comprehension in College Students

    Directory of Open Access Journals (Sweden)

    Charles Romel Yáñez Botello

    2013-12-01

    Full Text Available This is a descriptive research whose main objective was to describe the cognitive processes involved in reading and its relation to different levels of reading comprehension. For doing so, it was chosen a sample of 124 college students of Bogotá city. Participants- men and women between 16 and 30 years old- were studying first semester of psychology. The Evaluation Test for Reading Comprehension by Arenas (2007 was applied in order to describe cognitive operations. Moreover, results related to comprehension levels were analyzed through the Rasch Model. Besides, the Angof Methodology was used to specify the competence levels. It was concluded that there are five levels of reading comprehension. It must be said that most of the students were classified in the literal and inferential reading levels. Finally, the findings and limitations of the research were discussed.

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

    Science.gov (United States)

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

    2014-11-01

    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.

  12. High level nuclear waste treatment in the Defense Waste Processing Facility: Overview and integrated flowsheet model

    International Nuclear Information System (INIS)

    Design and construction of the world's largest vitrification facility for high level nuclear waste has been nearly completed at the US Department of Energy's Savannah River Site. Equipment testing and calibration are currently being performed in preparation for the nonradioactive Chemical Runs in the late 1991. In 1993, the Defense Waste Processing Facility (DWPF) will begin producing 100 kg/hr of radioactive waste glass at 28 wt% waste oxide loading. This paper describes all phases of waste processing operations in DWPF and waste tank farms using the integrated flowsheet modeling approach. Particular emphases are given to recent developments in the DWPF processes and design

  13. Molecular dynamics simulation of moderately coupled Yukawa liquids on graphics processing units

    International Nuclear Information System (INIS)

    Complete text of publication follows. During the past decade Graphic Processing Unit (GPU) architectures have seen not only continuous performance increase, but a completely new horizon through general purpose computing as well. Thus, being integrated inside personal computers (PC), besides high-performance graphics applications, they provide a new platform for scientific computing, too, at moderate cost. Single instruction multiple data (SIMD) parallelism of GPUs is attractive for molecular simulations, as particle methods can largely be parallelized. We have developed a molecular dynamics (MD) simulation code for the NVIDIA Compute Unified Device Architecture (CUDA) GPU architecture that allows massive parallel computing, thereby permitting relatively big systems to be simulated on PC class computers, compared to the traditional Central Processing Unit (CPU) computations. We have carried out simulations of moderately coupled (01. ? ? ? 10) 3-dimensional Yukawa liquids [2], using particle numbers in the 105-106 range. Besides the MD simulations we have as well obtained pair correlation functions using the Hypernetted Chain (HNC) Approximation, and have compared the results with the GPU-MD data. The analysis of the asymptotic long-range behaviour of the pair correlation functions (transition between monotonic vs. oscillating decay) confirmed the results of [3]. Figure 1 shows pair correlation functions obtained from the numerical simulationstained from the numerical simulations and the theoretical HNC method, in which the bridge function was set to zero. We find a very good agreement between the curves at ?=0.1 and 1, over several orders of magnitude. The only difference seen at ? = 10 is the (expected) slightly higher correlation peak amplitude obtained from the MD simulation, compared to the HNC result. We thank OTKA for supporting this work (grant K77653) and Dr A. Archer for useful discussions.

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

    CERN Document Server

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

    1999-01-01

    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. Two gasdynamic unsteady problems were used to study speedup and efficiency of the algorithms. The conditions of efficient application field for the algorithms have been determined. %%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%

  15. Molecular epidemiology and disinfectant susceptibility of Listeria monocytogenes from meat processing plants and human infections.

    Science.gov (United States)

    Heir, Even; Lindstedt, Bjørn-Arne; Røtterud, Ole-Johan; Vardund, Traute; Kapperud, Georg; Nesbakken, Truls

    2004-10-01

    We have investigated the molecular epidemiology of Listeria monocytogenes from the meat processing industry producing cold cuts and from cases of human listeriosis by discriminative pulsed-field gel electrophoresis (PFGE). A subset of the isolates was also investigated for susceptibility to a disinfectant based on quaternary ammonium compounds (QAC) frequently used in the meat processing industry. The purpose of this investigation was to obtain knowledge of sources, routes of contamination and genetic types of L. monocytogenes present along the production line in the meat processing industry, and to compare meat industry isolates and human isolates. Of the 222 isolates from four meat-processing plants, 200 were from two plants responsible for nearly 50% of the production of cold cuts in the Norwegian market. The strain collection included historical routinely sampled isolates (1989-2002) and isolates systematically sampled through a one year period (November 2001 to November 2002) from fresh meat and production environments in three plants. No isolates were obtained in samples from employees (throat, faeces). Human strains included all available reported isolates from Norwegian patients in selected time periods. The L. monocytogenes PFGE data showed a large genetic heterogeneity, with isolates separated into two genetic lineages and further subdivided into 56 different PFGE profiles. Certain profiles were observed on both sides of production (before and after heat treatment) indicating contamination of end products by fresh meat or fresh meat environments. While fresh meat isolates almost exclusively grouped within lineage I, isolates from end products showed a more balanced distribution between lineages I and II. Ten profiles were common among isolates from human and meat industry. Typing of human isolates identified a previously unrecognised outbreak. Generally, a higher QAC resistance incidence was observed among isolates from the meat processing industry than among human isolates although large plant to plant differences were indicated. No correlation between resistance and PFGE profile or resistance and persistence was observed. PMID:15358509

  16. Molecular design of photovoltaic materials for polymer solar cells: toward suitable electronic energy levels and broad absorption.

    Science.gov (United States)

    Li, Yongfang

    2012-05-15

    Bulk heterojunction (BHJ) polymer solar cells (PSCs) sandwich a blend layer of conjugated polymer donor and fullerene derivative acceptor between a transparent ITO positive electrode and a low work function metal negative electrode. In comparison with traditional inorganic semiconductor solar cells, PSCs offer a simpler device structure, easier fabrication, lower cost, and lighter weight, and these structures can be fabricated into flexible devices. But currently the power conversion efficiency (PCE) of the PSCs is not sufficient for future commercialization. The polymer donors and fullerene derivative acceptors are the key photovoltaic materials that will need to be optimized for high-performance PSCs. In this Account, I discuss the basic requirements and scientific issues in the molecular design of high efficiency photovoltaic molecules. I also summarize recent progress in electronic energy level engineering and absorption spectral broadening of the donor and acceptor photovoltaic materials by my research group and others. For high-efficiency conjugated polymer donors, key requirements are a narrower energy bandgap (E(g)) and broad absorption, relatively lower-lying HOMO (the highest occupied molecular orbital) level, and higher hole mobility. There are three strategies to meet these requirements: D-A copolymerization for narrower E(g) and lower-lying HOMO, substitution with electron-withdrawing groups for lower-lying HOMO, and two-dimensional conjugation for broad absorption and higher hole mobility. Moreover, better main chain planarity and less side chain steric hindrance could strengthen ?-? stacking and increase hole mobility. Furthermore, the molecular weight of the polymers also influences their photovoltaic performance. To produce high efficiency photovoltaic polymers, researchers should attempt to increase molecular weight while maintaining solubility. High-efficiency D-A copolymers have been obtained by using benzodithiophene (BDT), dithienosilole (DTS), or indacenodithiophene (IDT) donor unit and benzothiadiazole (BT), thienopyrrole-dione (TPD), or thiazolothiazole (TTz) acceptor units. The BDT unit with two thienyl conjugated side chains is a highly promising unit in constructing high-efficiency copolymer donor materials. The electron-withdrawing groups of ester, ketone, fluorine, or sulfonyl can effectively tune the HOMO energy levels downward. To improve the performance of fullerene derivative acceptors, researchers will need to strengthen absorption in the visible spectrum, upshift the LUMO (the lowest unoccupied molecular orbital) energy level, and increase the electron mobility. [6,6]-Phenyl-C(71)-butyric acid methyl ester (PC(70)BM) is superior to [6,6]-phenyl-C(61)-butyric acid methyl ester (PCBM) because C(70) absorbs visible light more efficiently. Indene-C(60) bisadduct (ICBA) and Indene-C(70) bisadduct (IC(70)BA) show 0.17 and 0.19 eV higher LUMO energy levels, respectively, than PCBM, due to the electron-rich character of indene and the effect of bisadduct. ICBA and IC(70)BA are excellent acceptors for the P3HT-based PSCs. PMID:22288572

  17. Comparison of cryoconite organic matter composition from Arctic and Antarctic glaciers at the molecular-level

    Science.gov (United States)

    Pautler, Brent G.; Dubnick, Ashley; Sharp, Martin J.; Simpson, André J.; Simpson, Myrna J.

    2013-03-01

    Glacier surfaces are reservoirs that contain organic and inorganic debris referred to as cryoconite. Solar heating of this material results in the formation of water-filled depressions that are colonized by a variety of microbes and are hypothesized to play a role in carbon cycling in glacier ecosystems. Recent studies on cryoconite deposits have focused on their contribution to carbon fluxes to determine whether they are a net source or sink for atmospheric CO2. To better understand carbon cycling in these unique ecosystems, the molecular constituents of cryoconite organic matter (COM) require further elucidation. COM samples from four glaciers were analyzed by targeted extraction of plant- and microbial-derived biomarkers in conjunction with non-targeted NMR experiments to determine the COM composition and potential sources. Several molecular proxies were applied to assess COM degradation and microbial activity using samples from Greenland, the Canadian Arctic, and Antarctica. COM from Canadian (John Evans glacier) and Greenlandic (Leverett glacier) locations was more chemically heterogeneous than that from the Antarctic likely due to inputs from higher plants, mosses and Sphagnum as suggested by the solvent-extractable alkyl lipids and sterols and the detection of lignin- and Sphagnum-derived phenols after cupric oxide chemolysis. Solid-state 13C nuclear magnetic resonance (NMR) experiments highlighted the bulk chemical functional groups of COM allowing for a general assessment of its degradation stage from the alkyl/O-alkyl proxy whereas solution-state 1H NMR highlighted both microbial and plant contributions to base-soluble extracts from these COM samples. The dominance of 1H NMR signals from microbial protein/peptides in base-soluble extracts of COM from Antarctica (Joyce glacier and Garwood glacier), phospholipid fatty acid (PLFA) biomarker detection and the absence of plant-derived biomarkers in both the solvent and cupric oxide extracts suggests that this COM is dominated by microbial-derived material. These results indicate that COM carbon composition is dependent on the local glacier environment which may have a profound impact on carbon cycling and sequestration on glacier surfaces.

  18. Effects of Diacerein at the Molecular Level in the Osteoarthritis Disease Process

    OpenAIRE

    Martel-pelletier, Johanne; Pelletier, Jean-pierre

    2010-01-01

    In osteoarthritis (OA), the alterations in joint tissues are numerous and involve morphological, biochemical and metabolic changes and an upregulation of the inflammatory pathways. The focus of this article is a brief narrative review of the effects of diacerein, an antirheumatic drug from the anthraquinone chemical class, and its active metabolite, rhein, on the factors that participate in the complex interaction between OA tissues and cells leading to the progression of joint structural cha...

  19. Effects of diacerein at the molecular level in the osteoarthritis disease process.

    Science.gov (United States)

    Martel-Pelletier, Johanne; Pelletier, Jean-Pierre

    2010-04-01

    In osteoarthritis (OA), the alterations in joint tissues are numerous and involve morphological, biochemical and metabolic changes and an upregulation of the inflammatory pathways. The focus of this article is a brief narrative review of the effects of diacerein, an antirheumatic drug from the anthraquinone chemical class, and its active metabolite, rhein, on the factors that participate in the complex interaction between OA tissues and cells leading to the progression of joint structural changes. PMID:22870441

  20. 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

  1. Level of Processing Modulates the Neural Correlates of Emotional Memory Formation

    Science.gov (United States)

    Ritchey, Maureen; LaBar, Kevin S.; Cabeza, Roberto

    2011-01-01

    Emotion is known to influence multiple aspects of memory formation, including the initial encoding of the memory trace and its consolidation over time. However, the neural mechanisms whereby emotion impacts memory encoding remain largely unexplored. The present study used a levels-of-processing manipulation to characterize the impact of emotion on…

  2. Level 2 Perspective Taking Entails Two Processes: Evidence from PRP Experiments

    Science.gov (United States)

    Janczyk, Markus

    2013-01-01

    In many situations people need to mentally adopt the (spatial) perspective of other persons, an ability that is referred to as "Level 2 perspective taking." Its underlying processes have been ascribed to mental self-rotation that can be dissociated from mental object-rotation. Recent findings suggest that perspective taking/self-rotation…

  3. Elaborations on the Socioegocentric and Dual-Level Connectionist Models of Group Interaction Processes

    Science.gov (United States)

    Hewes, Dean E.

    2009-01-01

    The purpose of the author's contribution to this colloquy was to spark conversation on the theoretical nature of communication processes and the evidentiary requirements for testing their relationship to group outcomes. Co-discussants have raised important issues concerning the philosophical basis of the socioegocentric model (SM) and dual-level…

  4. Internet Access, Use and Sharing Levels among Students during the Teaching-Learning Process

    Science.gov (United States)

    Tutkun, Omer F.

    2011-01-01

    The purpose of this study was to determine the awareness among students and levels regarding student access, use, and knowledge sharing during the teaching-learning process. The triangulation method was utilized in this study. The population of the research universe was 21,747. The student sample population was 1,292. Two different data collection…

  5. Testing for Level Shifts in Fractionally Integrated Processes: a State Space Approach

    DEFF Research Database (Denmark)

    Monache, Davide Delle; Grassi, stefano

    2015-01-01

    Short memory models contaminated by level shifts have similar long-memory features as fractionally integrated processes. This makes hard to verify whether the true data generating process is a pure fractionally integrated process when employing standard estimation methods based on the autocorrelation function or the periodogram. In this paper, we propose a robust testing procedure, based on an encompassing parametric specification that allows to disentangle the level shifts from the fractionally integrated component. The estimation is carried out on the basis of a state-space methodology and it leads to a robust estimate of the fractional integration parameter also in presence of level shifts. Once the memory parameter is correctly estimated, we use the KPSS test for presence of level shift. The Monte Carlo simulations show how this approach produces unbiased estimates of the memory parameter when shifts in the mean, or other slowly varying trends, are present in the data. Therefore, the subsequent robust version of the KPSS test for the presence of level shifts has proper size and by far the highest power compared to other existing tests. Finally, we illustrate the usefulness of the proposed approach on financial data, such as daily bipower variation and turnover.

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

    CERN Document Server

    Buras, Andrzej J

    2012-01-01

    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...

  7. Adenosine Receptor Expression in Two Different Human Cancer Cell Lines at Molecular Level

    Directory of Open Access Journals (Sweden)

    Panjehpour M

    2010-08-01

    Full Text Available Background: The metabolically active tumor cells may be characterized by a pronounced adenosine release that regulat es the growth and development of the tumor. Consequently, the expr ession pattern of defined re ceptor subtypes will be an important determinant for specific effects of adenosine on the control of tumor cell growth. In recent studies, the expression profile, signal transduction, molecular function and cell growth modulation of adenosine receptors in the human breast cancer cell lines has been reported. To i nvestigate the possible roles of adenosine receptors in other types of human cancers, in this study, we characterized the expression profile of adenosine receptors in two differen t human cancer cell lines: prostate carcinoma cell line (Du-145 and l ung adenocarcinoma cell line (Calu-6. Our purpose is to test the hypothesis t hat diverse human cancer cell lines, according to their adenosine receptor subclass status, would show differential growth modulation. Methods: RNA was extracted and re verse transcribed to cDNA. PCR primers were synthesized from human adenosi ne receptor cDNA sequen ces. PCR was performed under optimized condition for each recept or subtype. The PCR products were separated on agarose gels. Results: All two human cancer cell lines stud ied contained detectable amounts of mRNA specific for adenosine receptor except A 3 subtypes. Conclusion: In conclusion the differentially expressed genes identified in this study might provide new insights into the possible roles of adenosine receptors on cell growth and development.

  8. Canine Spontaneous Head and Neck Squamous Cell Carcinomas Represent Their Human Counterparts at the Molecular Level

    Science.gov (United States)

    Liu, Deli; Xiong, Huan; Ellis, Angela E.; Northrup, Nicole C.; Dobbin, Kevin K.; Shin, Dong M.; Zhao, Shaying

    2015-01-01

    Spontaneous canine head and neck squamous cell carcinoma (HNSCC) represents an excellent model of human HNSCC but is greatly understudied. To better understand and utilize this valuable resource, we performed a pilot study that represents its first genome-wide characterization by investigating 12 canine HNSCC cases, of which 9 are oral, via high density array comparative genomic hybridization and RNA-seq. The analyses reveal that these canine cancers recapitulate many molecular features of human HNSCC. These include analogous genomic copy number abnormality landscapes and sequence mutation patterns, recurrent alteration of known HNSCC genes and pathways (e.g., cell cycle, PI3K/AKT signaling), and comparably extensive heterogeneity. Amplification or overexpression of protein kinase genes, matrix metalloproteinase genes, and epithelial–mesenchymal transition genes TWIST1 and SNAI1 are also prominent in these canine tumors. This pilot study, along with a rapidly growing body of literature on canine cancer, reemphasizes the potential value of spontaneous canine cancers in HNSCC basic and translational research. PMID:26030765

  9. Canine spontaneous head and neck squamous cell carcinomas represent their human counterparts at the molecular level.

    Science.gov (United States)

    Liu, Deli; Xiong, Huan; Ellis, Angela E; Northrup, Nicole C; Dobbin, Kevin K; Shin, Dong M; Zhao, Shaying

    2015-06-01

    Spontaneous canine head and neck squamous cell carcinoma (HNSCC) represents an excellent model of human HNSCC but is greatly understudied. To better understand and utilize this valuable resource, we performed a pilot study that represents its first genome-wide characterization by investigating 12 canine HNSCC cases, of which 9 are oral, via high density array comparative genomic hybridization and RNA-seq. The analyses reveal that these canine cancers recapitulate many molecular features of human HNSCC. These include analogous genomic copy number abnormality landscapes and sequence mutation patterns, recurrent alteration of known HNSCC genes and pathways (e.g., cell cycle, PI3K/AKT signaling), and comparably extensive heterogeneity. Amplification or overexpression of protein kinase genes, matrix metalloproteinase genes, and epithelial-mesenchymal transition genes TWIST1 and SNAI1 are also prominent in these canine tumors. This pilot study, along with a rapidly growing body of literature on canine cancer, reemphasizes the potential value of spontaneous canine cancers in HNSCC basic and translational research. PMID:26030765

  10. Einstein–Bohr recoiling double-slit gedanken experiment performed at the molecular level

    Science.gov (United States)

    Liu, Xiao-Jing; Miao, Quan; Gel'Mukhanov, Faris; Patanen, Minna; Travnikova, Oksana; Nicolas, Christophe; Ågren, Hans; Ueda, Kiyoshi; Miron, Catalin

    2015-02-01

    Double-slit experiments illustrate the quintessential proof for wave–particle complementarity. If information is missing about which slit the particle has traversed, the particle, behaving as a wave, passes simultaneously through both slits. This wave-like behaviour and corresponding interference is absent if ‘which-slit’ information exists. The essence of Einstein–Bohr's debate about wave–particle duality was whether the momentum transfer between a particle and a recoiling slit could mark the path, thus destroying the interference. To measure the recoil of a slit, the slits should move independently. We showcase a materialization of this recoiling double-slit gedanken experiment by resonant X-ray photoemission from molecular oxygen for geometries near equilibrium (coupled slits) and in a dissociative state far away from equilibrium (decoupled slits). Interference is observed in the former case, while the electron momentum transfer quenches the interference in the latter case owing to Doppler labelling of the counter-propagating atomic slits, in full agreement with Bohr's complementarity.

  11. Level 1 Processing of MODIS Direct Broadcast Data at the GSFC DAAC

    Science.gov (United States)

    Lynnes, Christopher; Kempler, Steven J. (Technical Monitor)

    2001-01-01

    The GSFC DAAC is working to test and package the MODIS Level 1 Processing software for Aqua Direct Broadcast data. This entails the same code base, but different lookup tables for Aqua and Terra. However, the most significant change is the use of ancillary attitude and ephemeris files instead of orbit/attitude information within the science data stream (as with Terra). In addition, we are working on Linux: ports of the algorithms, which could eventually enable processing on PC clusters. Finally, the GSFC DAAC is also working with the GSFC Direct Readout laboratory to ingest Level 0 data from the GSFC DB antenna into the main DAAC, enabling level 1 production in near real time in support of applications users, such as the Synergy project. The mechanism developed for this could conceivably be extended to other participating stations.

  12. Application of a pulsed sonic liquid level device to chemical processing tanks

    International Nuclear Information System (INIS)

    The ever increasing concern over safeguards and accountability of nuclear material has prompted the need for a more accurate and reliable liquid level measurement device. Although accurate and reliable instruments were currently available, unique situations at the Rocky Flats Plant made most of these devices impractical. Some of the criteria used in the selection of a liquid level measurement device for use in the chemical processing areas of the plant included: (a) exceptional accuracy and reliability, (b) nonintrusiveness or nonpenetration of the process tank, (c) ease of installation, (d) standard interface electronics, (e) a digital display, and (f) moderate cost. This paper details the selection, operation, and production use of the Bartex Aquatrak Model LG-1101 Liquid Level Indicator 1. This was the only system tested which met or exceeded all of the requirements that were set. 2 references, 3 figures

  13. Local and Global Sea Level During the Last Interglacial: A Gaussian Process Approach

    Science.gov (United States)

    Kopp, R. E.; Simons, F. J.; Maloof, A. C.; Oppenheimer, M.

    2008-12-01

    Although its warmth was caused primarily by variations in Earth's orbital forcing, the Last Interglacial (LIG) stage (ca. 130-115 ka), with polar temperatures ~3-5 C warmer than today, serves as a partial analog for low-end future warming scenarios. Multiple indicators suggest LIG global sea level was higher than at present; based upon a small set of local sea level indicators, the IPCC Fourth Assessment Report inferred an elevation of ~4-6 m. Sea level is often mistakenly viewed as a simple function of changing global ice volume. This viewpoint neglects local variability, which arises from several factors, including the distortion of the geoid and the elastic and isostatic effects of lithospheric deformation by shifting ice masses. Accurate reconstruction of past global and local sea levels therefore requires integrating global data sets of local sea level indicators. Such attempts have rarely been made for periods predating the Last Glacial Maximum. To assess the robustness of the IPCC's global estimate and search for patterns in local sea level reflective of meltwater source, we have compiled a more comprehensive database that includes a variety of local sea level indicators, among them coral terraces, raised beaches, and sedimentological facies transitions, from sixty-five localities, as well as a global sea level record derived from oxygen isotopes. We generate a global synthesis from these data using a novel statistical approach based upon Gaussian process modeling. In Gaussian process modeling, as in the closely related geospatial technique of kriging interpolation, an estimate of a field value -- in this case, sea level -- at any arbitrary point of interest is derived from the data using a covariance function. We find an appropriate covariance function through a training process that employs pseudo-proxy data generated from a simple gravitational sea-level model under many plausible ice sheet histories. We use a Markov Chain Monte Carlo approach to account for geochronological errors. Analysis of synthetic histories suggest that the current data set is capable of resolving LIG global sea level with a 95% confidence interval of about ±2 m. Due to uncertainties in dating, it is unable to resolve robustly a short-lived mid-LIG lowstand like that proposed by several authors. We will present estimates of global and local sea level history during the LIG derived from this statistical approach.

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

    Directory of Open Access Journals (Sweden)

    Lin CL

    2012-10-01

    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

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

    OpenAIRE

    TakeshiSakurai

    2014-01-01

    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, bomby...

  16. 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)

  17. 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

  18. 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)

  19. Aquatic ecotoxicology: from the ecosystem to the cellular and molecular levels.

    OpenAIRE

    Boudou, A; Ribeyre, F

    1997-01-01

    This review of aquatic ecotoxicology is presented in three parts. First, we discuss the fundamental concepts and stress the importance of its ecological basis and the complexity and diversity of the field of investigation, which result from actions and interactions between the physicochemical characteristics of the biotopes, the structural and functional properties of the living organisms, and the contamination modalities. Ecotoxicological mechanisms, regardless of the level of biological com...

  20. Molecular basis of high-level ciprofloxacin resistance in Neisseria gonorrhoeae strains from Shandong Province, China

    Scientific Electronic Library Online (English)

    L.H., Zhao; S.P., Zhao.

    Full Text Available In the study, the ciprofloxacin resistance rate was 100%. High-level ciprofloxacin resistance rate was 63.55%. Sixteen different mutation patterns involved in the formation of ciprofloxacin resistance were identified. The most prevalent were patterns P7 (25.2%), P8 (15.0%), P9 (11.2%), P1 (10.3%), a [...] nd P5 (10.3%). All of the 107 NG isolates analyzed for mutations in the study have demonstrated a change of Ser-91 ? Phe in the gyrA gene, and all except one have demonstrated a change in position 95 of the amino acid sequence. All of the 68 high-level QRNG isolates had double mutations in gyrA gene combined with a single or two mutations in parC gene. It is most important that a new mutation site of Ile-97 ? Met in gyrA and a new mutation of Leu-106 ? Ile in parC were found in the study, both leading to high-level ciprofloxacin resistance (MIC values, 8 µg/mL, 32 µg/mL, respectively). Therefore, we confim that gyrA mutations are necessary for the fluoroquinolone resistance phenotype and parC mutations are correlated intimately with high-level fluoroquinolone resistance. In China fluoroquinolone resistance in Neisseria gonorrhoeae strains is very serious and the new mutation sites in the fluoroquinolone resistance-determining regions emerge more and more quickly. Hence, in China fluoroquinolones, which are used to treat gonorrhoea presently, should be substituted by a new antibiotics.

  1. Low-Molecular Weight Heparin Increases Circulating sFlt-1 Levels and Enhances Urinary Elimination

    OpenAIRE

    Hagmann, Henning; Bossung, Verena; Belaidi, Abdel Ali; Fridman, Alexander; Karumanchi, S Ananth; Thadhani, Ravi; Schermer, Bernhard; Mallmann, Peter; Schwarz, Guenter; Benzing, Thomas; Brinkkoetter, Paul T.

    2014-01-01

    Rationale: Preeclampsia is a devastating medical complication of pregnancy which leads to maternal and fetal morbidity and mortality. While the etiology of preeclampsia is unclear, human and animal studies suggest that excessive circulating levels of soluble fms-like tyrosine-kinase-1 (sFlt-1), an alternatively spliced variant of VEGF-receptor1, contribute to the signs and symptoms of preeclampsia. Since sFlt-1 binds to heparin and heparan sulfate proteoglycans, we hypothesized that the antic...

  2. Integration of molecular functions at the ecosystemic level: breakthroughs and future goals of environmental genomics and post-genomics

    OpenAIRE

    Vandenkoornhuyse, Philippe; Dufresne, Alexis; Quaiser, Achim; Gouesbet, Gwenola; Binet, Franc?oise; Francez, Andre?-jean; Mahe?, Ste?phane; Bormans, Myriam; Lagadeuc, Yvan; Coue?e, Ivan

    2010-01-01

    Environmental genomics and genome-wide expression approaches deal with large-scale sequence-based information obtained from environmental samples, at organismal, population or community levels. To date, environmental genomics, transcriptomics and proteomics are arguably the most powerful approaches to discover completely novel ecological functions and to link organismal capabilities, organism–environment interactions, functional diversity, ecosystem processes, evolution and Earth history. T...

  3. Fragile X and autism: Intertwined at the molecular level leading to targeted treatments

    Directory of Open Access Journals (Sweden)

    Hagerman Randi

    2010-09-01

    Full Text Available Abstract Fragile X syndrome (FXS is caused by an expanded CGG repeat (> 200 repeats in the 5' untranslated portion of the fragile mental retardation 1 gene (FMR1, leading to deficiency or absence of the FMR1 protein (FMRP. FMRP is an RNA carrier protein that controls the translation of several other genes that regulate synaptic development and plasticity. Autism occurs in approximately 30% of FXS cases, and pervasive developmental disorder, not otherwise specified (PDD-NOS occurs in an additional 30% of cases. Premutation repeat expansions (55 to 200 CGG repeats may also give rise to autism spectrum disorders (ASD, including both autism and PDD-NOS, through a different molecular mechanism that involves a direct toxic effect of the expanded CGG repeat FMR1 mRNA. RNA toxicity can also lead to aging effects including tremor, ataxia and cognitive decline, termed fragile X-associated tremor ataxia syndrome (FXTAS, in premutation carriers in late life. In studies of mice bearing premutation expansions, there is evidence of early postnatal neuronal cell toxicity, presenting as reduced cell longevity, decreased dendritic arborization and altered synaptic morphology. There is also evidence of mitochondrial dysfunction in premutation carriers. Many of the problems with cellular dysregulation in both premutation and full mutation neurons also parallel the cellular abnormalities that have been documented in autism without fragile X mutations. Research regarding dysregulation of neurotransmitter systems in FXS, including the metabotropic glutamate receptor (mGluR1/5 pathway and ? aminobutyric acid (GABAA pathways, have led to new targeted treatments for FXS. Preliminary evidence suggests that these new targeted treatments will also be beneficial in non-fragile X forms of autism.

  4. Effect of the natural winemaking process applied at industrial level on the microbiological and chemical characteristics of wine.

    Science.gov (United States)

    Sannino, Ciro; Francesca, Nicola; Corona, Onofrio; Settanni, Luca; Cruciata, Margherita; Moschetti, Giancarlo

    2013-09-01

    The composition of yeast and lactic acid bacteria (LAB) communities and the chemical evolution of the large-scale commercial vinification of Catarratto IGT Sicilia, carried out under the biological regime, was followed from grape harvest until bottling. Simultaneously to the maximum growth of yeasts, LAB counts reached high level of concentration (6-7 log CFU mL(-1)) during the first steps of the alcoholic fermentation. Yeast identification was determined applying different molecular methods. The highest species biodiversity was observed on grape and must samples taken soon after pressing. Saccharomyces cerevisiae was detected at dominant concentrations during the entire winemaking process. LAB cultures were grouped and identified by a combined phenotypic and genotypic approach. Leuconostoc mesenteroides, Lactobacillus hilgardii and Lactobacillus plantarum species were identified; the last was the main LAB recognized during vinification. The winemaking process was also chemically monitored. The alcoholic content was approximately 12.67% (v v(-1)) at bottling; pH, volatile acidity and total acidity showed a moderate increase during vinification. Tartaric, citric and malic acids decreased until bottling, while lactic acid showed a rapid increase at the end of maceration and bottling. Trans-caffeil tartaric acid was the most abundant phenolic compound and volatile organic compounds (VOC) were mainly represented by isoamylic alcohol, isobutanol, ethyl acetate and octanoic acid. PMID:23611824

  5. A Chemical Biology Approach to Interrogate Quorum Sensing Regulated Behaviors at the Molecular and Cellular Level

    OpenAIRE

    Lowery, Colin A.; Matamouros, Susana; Niessen, Sherry; Zhu, Jie; Scolnick, Jonathan A.; Mee, Jenny M.; Cravatt, Benjamin F.; Miller, Samuel I.; Kaufmann, Gunnar F.; Janda, Kim D.

    2013-01-01

    Small molecule probes have been employed extensively to explore biological systems and elucidate cellular signaling pathways. In this study, we utilize an inhibitor of bacterial communication to monitor changes in the proteome of Salmonella enterica serovar Typhimurium with the aim of discovering new processes regulated by AI-2-based quorum sensing (QS), a mechanism of bacterial intracellular communication that allows for the coordination of gene expression in a cell density-dependent manner....

  6. An atomic-level mechanism for activation of the kinesin molecular motors

    OpenAIRE

    Sindelar, Charles V.; Downing, Kenneth H

    2010-01-01

    Kinesin cytoskeletal motors convert the energy of ATP hydrolysis into stepping movement along microtubules. A partial model of this process has been derived from crystal structures, which show that movement of the motor domain relative to its major microtubule binding element, the switch II helix, is coupled to docking of kinesin’s neck linker element along the motor domain. This docking would displace the cargo in the direction of travel and so contribute to a step. However, the crystal stru...

  7. Molecular-Level Computer Simulation of a Vapor-Compression Refrigeration Cycle.

    Czech Academy of Sciences Publication Activity Database

    Figueroa-Gerstenmaier, S.; Francova, M.; Kowalski, M.; Lísal, Martin; Nezbeda, Ivo; Smith, W.R.

    2007-01-01

    Ro?. 259, ?. 2 (2007), s. 195-200. ISSN 0378-3812 R&D Projects: GA ?R(CZ) GA203/05/0725; GA AV ?R 1ET400720409; GA AV ?R 1ET400720507 Grant ostatní: NRCC(CA) OGP 1041 Institutional research plan: CEZ:AV0Z40720504 Source of funding: V - iné verejné zdroje Keywords : alternative refrigerants * joule-thomson expansion * adiabatic process Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.506, year: 2007

  8. Estimating reaction constants by ab initio molecular modeling: a study on the oxidation of phenol to catechol and hydroquinone in advanced oxidation processes

    Scientific Electronic Library Online (English)

    B., Ramos; J. P. S., Farah; A. C. S. C., Teixeira.

    2012-03-01

    Full Text Available Molecular modeling is growing as a research tool in Chemical Engineering studies, as can be seen by a simple research on the latest publications in the field. Molecular investigations retrieve information on properties often accessible only by expensive and time-consuming experimental techniques, su [...] ch as those involved in the study of radical-based chain reactions. In this work, different quantum chemical techniques were used to study phenol oxidation by hydroxyl radicals in Advanced Oxidation Processes used for wastewater treatment. The results obtained by applying a DFT-based model showed good agreement with experimental values available, as well as qualitative insights into the mechanism of the overall reaction chain. Solvation models were also tried, but were found to be limited for this reaction system within the considered theoretical level without further parameterization.

  9. Estimating reaction constants by ab initio molecular modeling: a study on the oxidation of phenol to catechol and hydroquinone in advanced oxidation processes

    Directory of Open Access Journals (Sweden)

    B. Ramos

    2012-03-01

    Full Text Available Molecular modeling is growing as a research tool in Chemical Engineering studies, as can be seen by a simple research on the latest publications in the field. Molecular investigations retrieve information on properties often accessible only by expensive and time-consuming experimental techniques, such as those involved in the study of radical-based chain reactions. In this work, different quantum chemical techniques were used to study phenol oxidation by hydroxyl radicals in Advanced Oxidation Processes used for wastewater treatment. The results obtained by applying a DFT-based model showed good agreement with experimental values available, as well as qualitative insights into the mechanism of the overall reaction chain. Solvation models were also tried, but were found to be limited for this reaction system within the considered theoretical level without further parameterization.

  10. The crystallization process of liquid vanadium studied by ab initio molecular dynamics

    International Nuclear Information System (INIS)

    We present a study of the crystallization process in liquid vanadium over a temperature range from 3000?K down to 1500?K using ab initio molecular dynamics simulations. Short-range order evolution during solidification is studied using various structural analysis methods. We show that the icosahedral-like short-range order is detected in the stable liquid phase and grows upon supercooling. The system undergoes a first-order phase transition (from a liquid to a solid state) at a temperature of about 1600?K. The crystal nucleation process is further studied using the time–temperature transformation mechanism by annealing the system at 1650?K. The nucleation is examined using bond-orientational order and density fluctuation analysis. Our finding is that various precursors appear in the region of high bond-orientational order with the majority having body-centered cubic (bcc)-like symmetry. This bcc-like region grows on annealing via thermal fluctuations. Our results reveal that the bond-orientational order precedes the density fluctuation, and is the main driving factor for nucleation. (papers)

  11. Recent Advances in Photoinduced Electron Transfer Processes of Fullerene-Based Molecular Assemblies and Nanocomposites

    Directory of Open Access Journals (Sweden)

    Osamu Ito

    2012-05-01

    Full Text Available Photosensitized electron-transfer processes of fullerenes hybridized with electron donating or other electron accepting molecules have been surveyed in this review on the basis of the recent results reported mainly from our laboratories. Fullerenes act as photo-sensitizing electron acceptors with respect to a wide variety of electron donors; in addition, fullerenes in the ground state also act as good electron acceptors in the presence of light-absorbing electron donors such as porphyrins. With single-wall carbon nanotubes (SWCNTs, the photoexcited fullerenes act as electron acceptor. In the case of triple fullerene/porphyrin/SWCNT architectures, the photoexcited porphyrins act as electron donors toward the fullerene and SWCNT. These mechanisms are rationalized with the molecular orbital considerations performed for these huge supramolecules. For the confirmation of the electron transfer processes, transient absorption methods have been used, in addition to time-resolved fluorescence spectral measurements. The kinetic data obtained in solution are found to be quite useful to predict the efficiencies of photovoltaic cells.

  12. Mineralization of the connective tissue: a complex molecular process leading to age-related loss of function.

    Science.gov (United States)

    Shindyapina, Anastasia V; Mkrtchyan, Garik V; Gneteeva, Tatiana; Buiucli, Sveatoslav; Tancowny, B; Kulka, M; Aliper, Alexander; Zhavoronkov, Alexander

    2014-04-01

    Age-related metastatic mineralization of soft tissues has been considered a passive and spontaneous process. Recent data have demonstrated that calcium salt deposition in soft tissues could be a highly regulated process. Although calcification occurs in any tissue type, vascular calcification has been of particular interest due to association with atherosclerosis, chronic kidney disease (CKD), and osteoporosis. Different mechanisms underlying calcium apatite accumulation are explored with these age-related disorders. In the case of atherosclerotic plaques, oxy-lipids trigger release of the pro-inflammatory cytokines and inflammation that activate calcification processes in aorta intimae. In CKD patients, renal failure alters the balance between calcium and phosphate levels usually regulated by fibroblast growth factor-23 (FGF23), Klotho, and vitamin D, and vascular smooth muscle cells (VSMCs) begin to explore an osteoblastosteoblast-like phenotype. Calcification could affect extracellular matrix along with VSMCs. Collagen is a major component of extracellular matrix and its modifications accumulate with age. The formation of cross-links between collagen fibers is regulated by the action of lysine hydroxylases and lysyl oxidase and could occur spontaneously. Oxidation-induced advanced glycation end products (AGEs) are a major type of spontaneous cross-links that accelerate with age and may result in tissue stiffness, problems with recycling, and potential accumulation of calcium apatite. Applying strategies for clearing the AGEs proposed by de Grey may be more difficult in the highly mineralized extracellular matrix. We performed bioinformatic analysis of the molecular pathways underlying calcification in atherosclerotic and CKD patients, signaling pathways of collagen cross-links formation, and bone mineralization, and we propose new potential targets and review drugs for calcification treatment. PMID:23902273

  13. Molecular endpoints as indicators of ecological risks from chronic, low-level irradiation. A problem of not connecting-the-dots

    International Nuclear Information System (INIS)

    Technological advances in molecular biology have made it feasible to use various types of molecular damage as endpoints in determining if biota are at risk from chronic, low-level exposures to ionizing radiation. The tacit assumption is that a molecular endpoint is indicative of an individual's health. Unfortunately, the type and quantity of molecular damage necessary to impact an individual organism or, more importantly, a population of organisms has yet to be determined. As a result, a disparity exists between molecular damage as an ecotoxicological endpoint and concomitant effects at the individual and population levels of biological organization. We think that the gap between molecular endpoints and population health can be bridged by correlating effects across numerous levels of biological organization, and by using the concept of resource allocation-based life histories to document how variation in resource allocation among individuals causes changes to the population. We suggest that a type of chromosome aberration (reciprocal translocations) are a potentially viable molecular endpoint for ecological risk from ionizing radiation because they are caused from DNA double strand breaks, a type of damage that is specific to radiation, they can be used as a biological dosimeter, and they are also known to reduce reproductive success, and thus it should be possible to couple the frequency of reciprocal chromosome translocations to an organism's life history traits ands to an organism's life history traits and population demography. (author)

  14. On applications of excess level processes to (N,D-policy bulk queueing systems

    Directory of Open Access Journals (Sweden)

    Jewgeni H. Dshalalow

    1996-01-01

    Full Text Available The paper deals with queueing systems in which N- and D-policies are combined into one. This means that an idle or vacationing server will resume his service if the queueing or workload process crosses some specified fixed level N or D, respectively. For the proposed (N,D-policy we study the queueing processes in models with and without server vacations, with compound Poisson input, and with generally distributed service and vacation periods. The analysis of the models is essentially based on fluctuation techniques for two-dimensional marked counting processes newly developed by the author. The results enable us to arrive at stationary distributions for the embedded and continuous time parameter queueing processes in closed analytic forms, enhancing the well-known Kendall formulas and their modifications.

  15. Excitation and deexcitation of N2 molecular levels. Induced fluorescence by electrons and laser

    International Nuclear Information System (INIS)

    The electron impact excitation followed by fluorescence induced by N2-laser absorption was used to study the lifetime of the lowest vibrational level of the B 3?g electronic state of N2. The experimental result of this work is 13 + 1 ?s. To measure the lifetime of B 3?g (v=2,3,5,6,7,8) levels the delayed coincidence method by electron impact was use. The lifetime values were compared with recent experimental and theoretical results. The relative intensi-ties of 3?g --- A 3??+ system bands, in the range (6540-10500 Ao) was measured using a hollow cathode lamp as spectral source. The relative transition moments and its dependence versus the r-centroid was obtained. Total cross sections for electron scattering by N molecules in the range 600 - 5000 eV have been obtained from measurements of the attenuation of a linear electron beam. The results have been compared with available experimental cross sections and with theoretical calculations based on the first Born approximation. (Author)

  16. Semiquantitative probe for radiation-induced normal tissue damage at the molecular level

    International Nuclear Information System (INIS)

    Sheep antibodies to bovine type I collagen were employed in the immunohistochemical detection of type I collagen in lung tissue sections of irradiated LAF1 mice. A video image digitizing system was developed to estimate collagen levels, by assigning a numerical value (0-63) to each of approximately 53,800 picture elements (pixels) in the microscope field, according to the collagen-dependent fluorescence intensity at each locus. For lungs harvested 52 weeks subsequent to graded doses of 60Co gamma radiation between 0 and 10 Gy, a dose-dependent increase in type I collagen was observed in the alveolar walls. A reproducible increase was evident for doses as low as 5 Gy: doses of 7 to 10 Gy elicited type I collagen levels significantly elevated with respect to those of age-matched controls. These results are consistent with a role for type I collagen in the development of radiation-induced pulmonary fibrosis. The assay system developed here will be used to explore the role of connective tissue macromolecules in the development of radiation pneumonitis and fibrosis

  17. [Effect of the fermentation process on levels of nitrates and nitrites in selected vegetables].

    Science.gov (United States)

    Heród-Leszczy?ska, T; Miedzobrodzka, A

    1992-01-01

    The aim of this study was to follow the changes in the levels of nitrates and nitrites throughout the process of fermentation of sauerkraut from white and red cabbage and red beets. The nitrate and nitrite levels were determined in raw and fermentation as well as in red beets and "beet acid" after a week of souring. Nitrate were determined by the brucine method, while nitrates by the Griess colorimetric method. Mean reduction of nitrates in sauerkraut (in relation to raw cabbage) was ca. 55.5% and that of nitrites ca. 76.7%. In the red sour cabbage a decrease in the level of nitrates in relation to the product by ca. 84.1% and in that of nitrites by ca. 67.4% was found. The stabilization of both nitrate levels in both kinds of cabbages followed as after the second month of storage, as confirmed by statistical analysis of the results. In the red beets after the process of fermentation a decrease in the level of nitrates by ca. 91.6% was noted. An undefined portion of the studied compounds passed into the liquid. The "beet acid" contained 595.9 mg/dm1 of nitrates and 3.26 mg/dm3 of nitrites. PMID:1308742

  18. Molecular sensors and molecular logic gates

    International Nuclear Information System (INIS)

    Full text: The rapid grow of nanotechnology field extended the concept of a macroscopic device to the molecular level. Because of this reason the design and synthesis of (supra)-molecular species capable of mimicking the functions of macroscopic devices are currently of great interest. Molecular devices operate via electronic and/or nuclear rearrangements and, like macroscopic devices, need energy to operate and communicate between their elements. The energy needed to make a device work can be supplied as chemical energy, electrical energy, or light. Luminescence is one of the most useful techniques to monitor the operation of molecular-level devices. This fact determinates the synthesis of novel fluorescence compounds as a considerable and inseparable part of nanoscience development. Further miniaturization of semiconductors in electronic field reaches their limit. Therefore the design and construction of molecular systems capable of performing complex logic functions is of great scientific interest now. In semiconductor devices the logic gates work using binary logic, where the signals are encoded as 0 and 1 (low and high current). This process is executable on molecular level by several ways, but the most common are based on the optical properties of the molecule switches encoding the low and high concentrations of the input guest molecules and the output fluorescent intensities with binary 0 and 1 respectively. The first proposal to execute logic operations at the molecular level was made in 1988, but the field developed only five years later when the analogy between molecular switches and logic gates was experimentally demonstrated by de Silva. There are seven basic logic gates: AND, OR, XOR, NOT, NAND, NOR and XNOR and all of them were achieved by molecules, the fluorescence switching as well. key words: fluorescence, molecular sensors, molecular logic gates

  19. A New Method for Processing Airborne Gamma Ray Spectrometry Data for Mapping Low Level Contaminations

    DEFF Research Database (Denmark)

    Aage, Helle Karina; Korsbech, Uffe C C

    1999-01-01

    A new technique for processing airborne gamma ray spectrometry data has been developed. It is based on the noise adjusted singular value decomposition method introduced by Hovgaard in 1997. The new technique opens for mapping of very low contamination levels. It is tested with data from Latvia where the remaining contamination from the 1986 Chernobyl accident together with fallout from the atmospheric nuclear weapon tests includes Cs-137 at levels often well below 1 kBq/m(2) equivalent surface contamination. The limiting factors for obtaining reliable results are radon in the air, spectrum stability and accurate altitude measurements. (C) 1999 Elsevier Science Ltd. All rights reserved.

  20. A multi-level code for metallurgical effects in metal-forming processes

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, P.A.; Silling, S.A. [Sandia National Labs., Albuquerque, NM (United States). Computational Physics and Mechanics Dept.; Hughes, D.A.; Bammann, D.J.; Chiesa, M.L. [Sandia National Labs., Livermore, CA (United States)

    1997-08-01

    The authors present the final report on a Laboratory-Directed Research and Development (LDRD) project, A Multi-level Code for Metallurgical Effects in metal-Forming Processes, performed during the fiscal years 1995 and 1996. The project focused on the development of new modeling capabilities for simulating forging and extrusion processes that typically display phenomenology occurring on two different length scales. In support of model fitting and code validation, ring compression and extrusion experiments were performed on 304L stainless steel, a material of interest in DOE nuclear weapons applications.

  1. Defense high-level waste management at the Idaho Chemical Processing Plant

    International Nuclear Information System (INIS)

    The Idaho Chemical Processing Plant reprocesses Department of Energy nuclear fuels for recovery of uranium. Acidic high-level liquid wastes are temporarily stored in stainless-steel tanks prior to solidification using a fluidized-bed calcining process. After solidification, the granular solid waste is stored in stainless-steel bins located within concrete vaults. Approximately 20,000 m3 of liquid waste has been reduced to 2800 m3 of solidified waste during 20 years of routine calcining operations. Alternative strategies for long-term waste management include in-place immobilization and repository disposal. Glass and ceramic are candidate waste forms to immobilize the waste

  2. Process technology for vitrification of defense high-level waste at the Savannah River Plant

    International Nuclear Information System (INIS)

    Vitrification in borosilicate glass is now the leading worldwide process for immobilizing high-level radioactive waste. Each vitrification project, however, has its unique mission and technical challenges. The Defense Waste Vitrification Facility (DWPF) now under construction at the Savannah River Plant will concentrate and vitrify a large amount of relatively low-power alkaline waste. Process research and development for the DWPF have produced significant advances in remote chemical operations, glass melting, off-gas treatment, slurry handling, decontamination, and welding. 6 references, 1 figure, 5 tables

  3. ORAC: a molecular dynamics simulation program to explore free energy surfaces in biomolecular systems at the atomistic level.

    Science.gov (United States)

    Marsili, Simone; Signorini, Giorgio Federico; Chelli, Riccardo; Marchi, Massimo; Procacci, Piero

    2010-04-15

    We present the new release of the ORAC engine (Procacci et al., Comput Chem 1997, 18, 1834), a FORTRAN suite to simulate complex biosystems at the atomistic level. The previous release of the ORAC code included multiple time steps integration, smooth particle mesh Ewald method, constant pressure and constant temperature simulations. The present release has been supplemented with the most advanced techniques for enhanced sampling in atomistic systems including replica exchange with solute tempering, metadynamics and steered molecular dynamics. All these computational technologies have been implemented for parallel architectures using the standard MPI communication protocol. ORAC is an open-source program distributed free of charge under the GNU general public license (GPL) at http://www.chim.unifi.it/orac. PMID:19824035

  4. Enhanced strength in reduced graphene oxide/nickel composites prepared by molecular-level mixing for structural applications

    Science.gov (United States)

    Zhao, Chao

    2015-02-01

    An effective molecular-level mixing approach was used to prepare reduced graphene oxide (rGO)/Ni powders, which were directly consolidated into rGO/Ni composites by spark plasma sintering. The rGO/Ni composites were found to exhibit a homogeneous dispersion of rGO and a strong interfacial bonding between the rGO and the Ni matrix. The enhanced interfacial bonding was attributed to the oxygen-mediated bonding generated from the interactions between the residue functional groups of rGO and the Ni atoms. Tensile test revealed that 1.5 wt% rGO/Ni composites demonstrated a 95.2 % increase in tensile strength and a 327.6 % increase in yield strength, while simultaneously retained a 12.1 % of elongation. This study thus proposed an effective way to fabricate rGO/Ni composites with enhanced tensile properties.

  5. Levels of some molecular and biochemical tumor markers in Egyptian patients with different grades and stages of bladder cancer

    International Nuclear Information System (INIS)

    This study enrolled 64 patients with bladder cancer disease, 54 of them treated by surgery and 10 by radiotherapy. The patients were classified according to their clinical data that include infection with bilharziasis, grade, stage and type of tumor. The present study included determination of telomerase activity in tissue and urine using molecular methods and the levels of nuclear matrix protein 22 (NMP22) and fibronectin in urine. The applied tumor markers showed significant differences in malignant patients compared to control. The same picture was noticed in case of patients received radiotherapy but less pronounced. The results revealed that there is significant correlation between the three tumor markers and the grade of tumor, while NMP22 and fibronectin correlated with stage. Moreover, fibronectin only have significant correlation with the infection with the bilharziasis. The results indicated that determination of telomerase, fibronectin and NMP22 can give clear idea about the development of malignancy and may help in the prediction of cancer recurrence

  6. Effect of Chayotte Extract on the Biochemical Determinations and on Molecular and Cellular Levels

    Directory of Open Access Journals (Sweden)

    M.L. Gomes

    2004-01-01

    Full Text Available The use of natural products occurs around the world. The labeling of blood constituents with technetium-99m (99m Tc has been influenced by natural extracts. We evaluated the influence of a chayotte(Sechium edule extract on the labeling of blood elements with 99m Tc, in the structural conformation of DNA, in the biochemistry of blood and in the measurement of. blood pressure. The animals were treated with chayotte during 15 days and samples of blood were withdrawn. The samples were incubated with stannous chloride and with 99mTc. Plasma(P and blood cells (BC were isolated, also precipitated with trichloroacetic acid and soluble(SF and insoluble fractions(IF separated. There was a decrease in the radioactivity in IF-P(from 83.96 ± 4.28 to 53.26 ± 6.69. Samples of blood from the treated group were carried out with specific biochemistry kits and the blood biochemistry analysis compounds was done. It was analyzed the level of uric acid, albumin, cholesterol, creatinine, glucose, high density lipoprotein (HDL, globulin and trigliceridics. The gauging of the blood pressure of the animals was taken. Our results showed a reduction on the level of glucose (from 118.40 ± 10.69 to 97.20 ± 4.32 and globulin (3.52 ± 0.13 to 3.08 ± 0.19 as well as in the diastolic pressure (from 123.80 ± 9.12 to 84.40 ± 3.85. It was observed that the referred extract has induced lesions on the DNA molecule. The effect of chayotte extract probably, could be explained by the metabolization of the chayotte that could be capable to induce the generation of active metabolites with oxidant properties.

  7. Self-energy-corrected electronic energy level alignment in molecular junctions and at interfaces with hybrid functionals

    Science.gov (United States)

    Kotiuga, Michele; Egger, David; Kronik, Leeor; Neaton, Jeffrey B.

    2015-03-01

    Accurate calculations of energy level alignment at complex interfaces are imperative for understanding a variety of transport and spectroscopy measurements, as well as for elucidating new interfacial electronic structure phenomena. However, standard approaches to such calculations, based on density functional theory (DFT), are well known to be deficient. In prior work on molecular junctions and physisorbed molecules on surfaces, an approximate GW approach, DFT+ ?, has been successful in describing the conductance and level alignment of amine and pyridine terminated molecules on gold surfaces and in junctions. Here, via the use of hybrid functionals, we preform quantitative studies of the level alignment of thiol- and carbon-terminated phenyls on gold, where the formation of a strong chemical bond and presence of gateway states limit the validity of the DFT+ ? approximation as currently formulated. We contrast these systems to prior work on weakly-coupled molecules, including bipyridine or phenyl-diamines. Additionally, we compute transmission functions using both DFT-PBE and DFT-HSE starting points and predict conductance and thermopower with these methods, comparing to experiments where possible. We acknowledge DOE, DOD, NERSC, ERC, ISF, and FWF.

  8. Weld transference modes identification through sound pressure level in GMAW process

    Directory of Open Access Journals (Sweden)

    S.C. Absi Alfaro

    2008-07-01

    Full Text Available Purpose: One of the most used processes in the industry is GMAW, in this welding process there is physical phenomena such as the temperature, electromagnetic field, luminosity and sound pressure. It is known that GMAW weld specialized techinicisian combine visual and sound at the work to garantee the process stability. It is important to improve the final weld quality; therefore, the quantification of electrical and acoustical behaviour - within the audible bands, offer an information that is important to comprehend his impirical rules.Design/methodology/approach: With these he can identify the transfer mode, instabilities in the process, determine defects and evaluate the weld quality along the weld bead. The sound signal is captured simultaneously with the arc voltage and current signals. Was proved that first derived from the instantaneous power of the electrical arc presents a behaviour similar to the acoustical with a delay, because the measured sound is airborne.Findings: This relation was corroborated by the comparison between the sound pressure level calculated by electrical signals and by acoustical signals. This relation presented a similarity between the calculated signals greater than that between the sound and the power first derived.Practical implications: Besides that, with the sound pressure level it is possible to identify process instabilities that is not so trivial to realize with the sound pressure signal. In spite of it, the identification of instabilities for the globular and spray tranfer modes displays greater difficulty than that for the short circuit transfer mode. It was shown that the acoustical weld sensing offers information about the behaviour of the tranfer mode and the process stability.Originality/value: The sound quantification would be applied as a control variable for the weld process. Thus, it would be possible to develop similar control strategies as those applied by specialized workers.

  9. Vibronic state symmetry, selection rules and transition probabilities for a molecular rearrangement process. The butadiene-cyclobutene rearrangement

    International Nuclear Information System (INIS)

    Permutation-inversion group theory is applied to the classification of vibronic states, selection rules, and transition probabilities for a molecular rearrangement process in which the nuclear configuration of the molecule changes substantially. The advantages of the permutation-inversion group in this respect is that it is independent of any particular nuclear configuration. (Auth.)

  10. [Crystallographic and molecular structure of trihexosyl-ceramide deposits characteristic of Fabry's disease (particularly the rheumatic form). Digital imaging processing].

    Science.gov (United States)

    Delbarre, F; Laoussadi, S; Dupoisot, H; Morizet, J; Constans, A; Daury, G

    1981-02-01

    The ceramide trihexoside inclusions, which characterize Fabry-Anderson disease, have been studied using electron microscopy and digital image processing. Results are given showing the various apparent periodicities of the inclusion lamellae and the orientation, perpendicular to the lamellae or oblique, of the ceramide molecular component. PMID:6261982

  11. Level of Aflatoxin in Some Fish Feeds from Fish Farming Processes, Feed Factories and Imported Feeds

    OpenAIRE

    Altug?, Gu?ls?en

    2003-01-01

    Aflatoxins that are toxic metabolites for human and animals were determined in some fish feed. Eighty-five unit samples taken from "fish farming processes", "feed factories" and "imported feeds" in 1998, 1999 and 2000 were analyzed. In the analysis, thin layer chromatography (TLC) and enzyme linked immunosorbent assay (ELISA) technique were used. Consequently, aflatoxin levels above 20 ppb were detected in 20 samples and from 21.2 to 42.4 ppb in 85 samples. In 2...

  12. Alternatives generation and analysis for the phase 1 high-level waste pretreatment process selection

    International Nuclear Information System (INIS)

    This report evaluates the effects of enhanced sludge washing and sludge washing without caustic leaching during the preparation of the Phase 1 high-level waste feeds. The pretreatment processing alternatives are evaluated against their ability to satisfy contractual, cost minimization, and other criteria. The information contained in this report is consistent with, and supplemental to, the Tank Waste Remediation System Operation and Utilization Plan (Kirkbride et al. 1997)

  13. Alternatives generation and analysis for the phase 1 high-level waste pretreatment process selection

    Energy Technology Data Exchange (ETDEWEB)

    Manuel, A.F.

    1997-10-02

    This report evaluates the effects of enhanced sludge washing and sludge washing without caustic leaching during the preparation of the Phase 1 high-level waste feeds. The pretreatment processing alternatives are evaluated against their ability to satisfy contractual, cost minimization, and other criteria. The information contained in this report is consistent with, and supplemental to, the Tank Waste Remediation System Operation and Utilization Plan (Kirkbride et al. 1997).

  14. Processability and electrical characteristics of glass substrates for RF wafer-level chip-scale packages

    OpenAIRE

    Polyakov, A.; Mendes, P. M.; Sinaga, S. M.; Bartek, M.; Rejaei, B.; Correia, J. H.; Burghartz, J. N.

    2003-01-01

    Various types of glass substrates have been compared with respect to their suitability as a low-loss substrate in wafer-level chip-scale packaging for RF applications. Processability has been evaluated by fabrication of shallow and deep recesses using wet etching in HF (/H3PO4) solutions. Electrical characteristics (dielectric constant and attenuation) have been extracted from measurements on coplanar wave guides (CPWs) up to 10 GHz. Results show that Coming Pyrex #7740 glass provides opti...

  15. Design of Self-tuning PID controller using Fuzzy Logic for Level Process

    OpenAIRE

    P D Aditya Karthik *1; J Supriyanka 2

    2014-01-01

    In this paper a self-tuning PID controller is designed using fuzzy logic for a liquid level process of single tank and two tank systems. Conventional technique like Ziegler’s Nichols method can be enhanced using fuzzy logic. The gain parameters that are obtained using conventional technique can be adjusted automatically using the logic. The gain parameters that are obtained using conventional technique can be adjusted automatically using the

  16. The change of intracellular NAD level at the process of fusarium sambucinum growth and development

    International Nuclear Information System (INIS)

    Alterations of intracellular NAD(Nicotinamide-Adenine Dinucleotide) level have been studied in the process of growth and development of Fusanium sambucinum, selected earlier as a potential NAD producer. It was established that essential fluctuations of NAD concentration are dependent on growth phase, morphological cell type and DNA biosynthesis, that allowed to propose a real linkage between coenzyme pool and replicative activity of cells. (author). 7 refs., 2 figs

  17. Feasibility of centralizing disposal and processing facilities for low-level biomedical waste

    International Nuclear Information System (INIS)

    Research efforts were designed to examine the feasibility of a centralized processing facility for low level radioactive waste materials. The scope of the proposed facility was to provide a regional commercial processing service to medicine and biomedical research institutions who are unable to perform waste processing or treatment for themselves. The results of a literature search has provided an extensive description of low level wastes on a national basis. Sufficient information is now available concerning waste types, physical and chemical forms, radionuclide types and quantities, and volumes on a regional basis to support the operation of a reprocessing facility. Specifically, the total low level biomedical waste volume generated in the US during 1980 was approximately 660,000 cu ft. Commercial reprocessing operations which could handle approximately 81% of this volume and achieve a gross effective volume reduction ratio of 4 to 1 (including materials totally disposed of by the reprocessor) would be supported by a 15 million dollar annual industry. New technologies exist which are not currently used in commercial operations. There is an excellent potential for their use to provide an increase in the volume reduction rates on a cost effective basis. Current volume reduction rates of 3-5:1 could be increased to 10:1

  18. EOS MLS Level 1B Data Processing, Version 2.2

    Science.gov (United States)

    Perun, Vincent; Jarnot, Robert; Pickett, Herbert; Cofield, Richard; Schwartz, Michael; Wagner, Paul

    2009-01-01

    A computer program performs level- 1B processing (the term 1B is explained below) of data from observations of the limb of the Earth by the Earth Observing System (EOS) Microwave Limb Sounder (MLS), which is an instrument aboard the Aura spacecraft. This software accepts, as input, the raw EOS MLS scientific and engineering data and the Aura spacecraft ephemeris and attitude data. Its output consists of calibrated instrument radiances and associated engineering and diagnostic data. [This software is one of several computer programs, denoted product generation executives (PGEs), for processing EOS MLS data. Starting from level 0 (representing the aforementioned raw data, the PGEs and their data products are denoted by alphanumeric labels (e.g., 1B and 2) that signify the successive stages of processing.] At the time of this reporting, this software is at version 2.2 and incorporates improvements over a prior version that make the code more robust, improve calibration, provide more diagnostic outputs, improve the interface with the Level 2 PGE, and effect a 15-percent reduction in file sizes by use of data compression.

  19. Research Frontiers in Bioinspired Energy: Molecular-Level Learning from Natural Systems: A Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Zolandz, Dorothy

    2012-03-28

    An interactive, multidisciplinary, public workshop, organized by a group of experts in biochemistry, biophysics, chemical and biomolecular engineering, chemistry, microbial metabolism, and protein structure and function, was held on January 6-7, 2011 in Washington, DC. Fundamental insights into the biological energy capture, storage, and transformation processes provided by speakers was featured in this workshop?which included topics such as microbes living in extreme environments such as hydrothermal vents or caustic soda lakes (extremophiles)? provided a fascinating basis for discussing the exploration and development of new energy systems. Breakout sessions and extended discussions among the multidisciplinary groups of participants in the workshop fostered information sharing and possible collaborations on future bioinspired research. Printed and web-based materials that summarize the committee?s assessment of what transpired at the workshop were prepared to advance further understanding of fundamental chemical properties of biological systems within and between the disciplines. In addition, webbased materials (including two animated videos) were developed to make the workshop content more accessible to a broad audience of students and researchers working across disciplinary boundaries. Key workshop discussion topics included: Exploring and identifying novel organisms; Identifying patterns and conserved biological structures in nature; Exploring and identifying fundamental properties and mechanisms of known biological systems; Supporting current, and creating new, opportunities for interdisciplinary education, training, and outreach; and Applying knowledge from biology to create new devices and sustainable technology.

  20. The effects of melatonin on a molecular level Die effekte van melatonien op molekulêre vlak

    Directory of Open Access Journals (Sweden)

    M. Haag

    1992-07-01

    Full Text Available The indole hormone melatonin is secreted in a biphasic circadian rhythm by the pineal gland. This review presents a summary of recent results concerning — (i factors that influence melatonin synthesis; (ii the existence of melatonin receptors in brain tissue; (iii the effects of melatonin as a modulator of dopaminergic, noradrenergic, GABAergic and opioidergic neurotransmitter processes; (iv the influence of melatonin on the electric activity and metabolic rate of certain brain nuclei; and (v melatonin effects on hormone secretion in the hypothalamic-pituitary axis. A basic mechanism of melatonin action via cyclic nucleotides and thus protein phosphorylation is presented.Die indoolhormoon melatonien word volgens 'n bifasiese sirkadiese ritme deur die pineaalklier afgeskei. Hierdie oorsigartikel bied ’n opsomming van onlangse resultate oor: (i faktore wat melatoniensekresie beinvloed; (ii die bestaan van melatonienreseptore in breinweefsel; (Hi effekte van melatonien as ’n moduleerder van dopaminergiese, noradrenergiese, GABA-ergiese en opioiedergiese neuro- oordragsprosesse; (iv die invloed van melatonien op elektriese aktiwiteit en metaboliese snelheid van sekere breinkerne; asook (v melatonieneffekte op hormoonafskeiding in die hipotalamus-hipofise-as. ’n Grondliggende meganisme van melatonienwerking deur middel van sikliese nukleotiede en proteienfosforilering word verder voorgestel.

  1. Computational methods for molecular imaging

    CERN Document Server

    Shi, Kuangyu; Li, Shuo

    2015-01-01

    This volume contains original submissions on the development and application of molecular imaging computing. The editors invited authors to submit high-quality contributions on a wide range of topics including, but not limited to: • Image Synthesis & Reconstruction of Emission Tomography (PET, SPECT) and other Molecular Imaging Modalities • Molecular Imaging Enhancement • Data Analysis of Clinical & Pre-clinical Molecular Imaging • Multi-Modal Image Processing (PET/CT, PET/MR, SPECT/CT, etc.) • Machine Learning and Data Mining in Molecular Imaging. Molecular imaging is an evolving clinical and research discipline enabling the visualization, characterization and quantification of biological processes taking place at the cellular and subcellular levels within intact living subjects. Computational methods play an important role in the development of molecular imaging, from image synthesis to data analysis and from clinical diagnosis to therapy individualization. This work will bring readers fro...

  2. The influence of adiponectin G276T gene polymorphism on changes in total and high molecular weight adiponectin levels by exercise training

    Directory of Open Access Journals (Sweden)

    Daisuke Ando

    2011-12-01

    Full Text Available Adiponectin is an adipocyte-secreted hormone and regulates the metabolism of lipid and glucose. We examined the influence of adiponectin G276T gene polymorphism on changes in total or high molecular weight adiponectin levels by exercise training. A randomized parallel-design study (n = 53; 40 women and 13 men; age range, 32 - 65 years was conducted. Participants were randomly assigned to the exercise (n = 26 or control (n = 27 group and received exercise training for 70 min 2 times per week for 12 weeks and exercise advice at the baseline, respectively. Blood sample were obtained before and after the intervention. The primary outcomes were changes in total adiponectin and high molecular weight adiponectin levels. At the baseline, the participants with and without 276G allele did not differ with the total and high molecular weight adiponectin levels in the entire study population. No significant difference in the change in the total and high molecular weight adiponectin levels between the subjects with the G276G genotype and 276T allele carriers were found. This study provides evidence that the G276T polymorphism of the adiponectin gene is not associated with the magnitude of the effect of twice-weekly exercise training on the total and high molecular weight adiponectin levels.

  3. Grounding cognitive-level processes in behavior: the view from dynamic systems theory.

    Science.gov (United States)

    Samuelson, Larissa K; Jenkins, Gavin W; Spencer, John P

    2015-04-01

    Marr's seminal work laid out a program of research by specifying key questions for cognitive science at different levels of analysis. Because dynamic systems theory (DST) focuses on time and interdependence of components, DST research programs come to very different conclusions regarding the nature of cognitive change. We review a specific DST approach to cognitive-level processes: dynamic field theory (DFT). We review research applying DFT to several cognitive-level processes: object permanence, naming hierarchical categories, and inferring intent, that demonstrate the difference in understanding of behavior and cognition that results from a DST perspective. These point to a central challenge for cognitive science research as defined by Marr-emergence. We argue that appreciating emergence raises questions about the utility of computational-level analyses and opens the door to insights concerning the origin of novel forms of behavior and thought (e.g., a new chess strategy). We contend this is one of the most fundamental questions about cognition and behavior. PMID:25755203

  4. Ganoderma spores may regulate the levels of mitochondria-related molecular substances in hippocampus of young rats birthed by rats with gestational hypertension

    OpenAIRE

    Jin-jun CHENG; Zeng, Yuan-shan

    2007-01-01

    Objective: To investigate the effects of Ganoderma spores on mitochondria-related molecular substances in hippocampus of young rats birthed by rats with gestational hypertension.Methods: Nitric oxide synthase (NOS) inhibitor Nw-nitro-L-arginine methylester (L-NAME) was intraperitoneally injected into pregnant rats to induce gestational hypertension, and Ganoderma spores were administered orally. The effects of Ganoderma spores on levels of mitochondria-related molecular substances in hippocam...

  5. Efficient Simulation Modeling of an Integrated High-Level-Waste Processing Complex

    International Nuclear Information System (INIS)

    An integrated computational tool named the Production Planning Model (ProdMod) has been developed to simulate the operation of the entire high-level-waste complex (HLW) at the Savannah River Site (SRS) over its full life cycle. ProdMod is used to guide SRS management in operating the waste complex in an economically efficient and environmentally sound manner. SRS HLW operations are modeled using coupled algebraic equations. The dynamic nature of plant processes is modeled in the form of a linear construct in which the time dependence is implicit. Batch processes are modeled in discrete event-space, while continuous processes are modeled in time-space. The ProdMod methodology maps between event-space and time-space such that the inherent mathematical discontinuities in batch process simulation are avoided without sacrificing any of the necessary detail in the batch recipe steps. Modeling the processes separately in event- and time-space using linear constructs, and then coupling the two spaces, has accelerated the speed of simulation compared to a typical dynamic simulation. The ProdMod simulator models have been validated against operating data and other computer codes. Case studies have demonstrated the usefulness of the ProdMod simulator in developing strategies that demonstrate significant cost savings in operating the SRS HLW complex and in verifying the feasibility of newly proposed processes

  6. Molecular neuropathology of MELAS: level of heteroplasmy in individual neurones and evidence of extensive vascular involvement.

    Science.gov (United States)

    Betts, J; Jaros, E; Perry, R H; Schaefer, A M; Taylor, R W; Abdel-All, Z; Lightowlers, R N; Turnbull, D M

    2006-08-01

    Mitochondrial DNA (mtDNA) disease is an important genetic cause of neurological disability. A variety of different clinical features are observed and one of the most common phenotypes is MELAS (Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis and Stroke-like episodes). The majority of patients with MELAS have the 3243A>G mtDNA mutation. The neuropathology is dominated by multifocal infarct-like lesions in the posterior cortex, thought to underlie the stroke-like episodes seen in patients. To investigate the relationship between mtDNA mutation load, mitochondrial dysfunction and neuropathological features in MELAS, we studied individual neurones from several brain regions of two individuals with the 3243A>G mutation using dual cytochrome c oxidase (COX) and succinate dehydrogenase (SDH) histochemistry, and Polymerase Chain Reaction Restriction Fragment Lenght Polymorphism (PCR-RFLP) analysis. We found a low number of COX-deficient neurones in all brain regions. There appeared to be no correlation between the threshold level for the 3243A>G mutation to cause COX deficiency within single neurones and the degree of pathology in affected brain regions. The most severe COX deficiency associated with the highest proportion of mutated mtDNA was present in the walls of the leptomeningeal and cortical blood vessels in all brain regions. We conclude that vascular mitochondrial dysfunction is important in the pathogenesis of the stroke-like episodes in MELAS patients. As migraine is a commonly encountered feature in MELAS, we propose that coupling of the vascular mitochondrial dysfunction with cortical spreading depression (CSD) might underlie the selective distribution of ischaemic lesions in the posterior cortex in these patients. PMID:16866982

  7. Molecular mapping to species level of the tonsillar crypt microbiota associated with health and recurrent tonsillitis

    DEFF Research Database (Denmark)

    Jensen, Anders; Fagö-Olsen, Helena

    2013-01-01

    The human palatine tonsils, which belong to the central antigen handling sites of the mucosal immune system, are frequently affected by acute and recurrent infections. This study compared the microbiota of the tonsillar crypts in children and adults affected by recurrent tonsillitis with that of healthy adults and children with tonsillar hyperplasia. An in-depth 16S rRNA gene based pyrosequencing approach combined with a novel strategy that included phylogenetic analysis and detection of species-specific sequence signatures enabled identification of the major part of the microbiota to species level. A complex microbiota consisting of between 42 and 110 taxa was demonstrated in both children and adults. This included a core microbiome of 12 abundant genera found in all samples regardless of age and health status. Yet, Haemophilus influenzae, Neisseria species, and Streptococcus pneumoniae were almost exclusively detected in children. In contrast, Streptococcus pseudopneumoniae was present in all samples. Obligate anaerobes like Porphyromonas, Prevotella, and Fusobacterium were abundantly present in children, but the species diversity of Porphyromonas and Prevotella was larger in adults and included species that are considered putative pathogens in periodontal diseases, i.e. Porphyromonas gingivalis, Porphyromonas endodontalis, and Tannerella forsythia. Unifrac analysis showed that recurrent tonsillitis is associated with a shift in the microbiota of the tonsillar crypts. Fusobacterium necrophorum, Streptococcus intermedius and Prevotella melaninogenica/histicola were associated with recurrent tonsillitis in adults, whereas species traditionally associated with acute tonsillitis like pyogenic streptococci and Staphylococcus aureus were scarce. The findings suggest that recurrent tonsillitis is a polymicrobial infection in which interactions within consortia of taxa play an etiologic role. The study contributes to the human microbiome data, to the understanding of the etiology of infections affecting the tonsils, and forms a basis for further insight into the consequences of the intense microbe-host interactions that take place in the tonsils.

  8. Molecular Mapping to Species Level of the Tonsillar Crypt Microbiota Associated with Health and Recurrent Tonsillitis

    DEFF Research Database (Denmark)

    Jensen, Anders; Fagö-Olsen, Helena

    2013-01-01

    The human palatine tonsils, which belong to the central antigen handling sites of the mucosal immune system, are frequently affected by acute and recurrent infections. This study compared the microbiota of the tonsillar crypts in children and adults affected by recurrent tonsillitis with that of healthy adults and children with tonsillar hyperplasia. An in-depth 16S rRNA gene based pyrosequencing approach combined with a novel strategy that included phylogenetic analysis and detection of species-specific sequence signatures enabled identification of the major part of the microbiota to species level. A complex microbiota consisting of between 42 and 110 taxa was demonstrated in both children and adults. This included a core microbiome of 12 abundant genera found in all samples regardless of age and health status. Yet, Haemophilus influenzae, Neisseria species, and Streptococcus pneumoniae were almost exclusively detected in children. In contrast, Streptococcus pseudopneumoniae was present in all samples. Obligate anaerobes like Porphyromonas, Prevotella, and Fusobacterium were abundantly present in children, but the species diversity of Porphyromonas and Prevotella was larger in adults and included species that are considered putative pathogens in periodontal diseases, i.e. Porphyromonas gingivalis, Porphyromonas endodontalis, and Tannerella forsythia. Unifrac analysis showed that recurrent tonsillitis is associated with a shift in the microbiota of the tonsillar crypts. Fusobacterium necrophorum, Streptococcus intermedius and Prevotella melaninogenica/histicola were associated with recurrent tonsillitis in adults, whereas species traditionally associated with acute tonsillitis like pyogenic streptococci and Staphylococcus aureus were scarce. The findings suggest that recurrent tonsillitis is a polymicrobial infection in which interactions within consortia of taxa play an etiologic role. The study contributes to the human microbiome data, to the understanding of the etiology of infections affecting the tonsils, and forms a basis for further insight into the consequences of the intense microbe-host interactions that take place in the tonsils.

  9. Understanding thermodynamic properties at the molecular level: multiple temperature charge density study of ribitol and xylitol.

    Science.gov (United States)

    Madsen, Anders Østergaard; Mattson, Rikke; Larsen, Sine

    2011-07-01

    X-ray diffraction data of high quality measured to high resolution on crystals of the two pentitol epimers ribitol (centric) and xylitol (acentric) at 101, 141, and 181 K and data on the two compounds previously recorded at 122 K have formed the basis for multipole refinements with the VALRAY system. Our analysis showed that it is possible to obtain a reliable crystal electron density for an acentric compound (xylitol) from X-ray diffraction data and that the thermal motion can be deconvoluted from the static density in this temperature range. The Bader-type topological analysis of the static electron densities revealed virtually identical intramolecular interactions as well as very similar hydrogen bond interactions of ribitol and xylitol; the only minor differences are found in the weaker intermolecular interactions. The high-level periodic DFT calculations are in accordance with the thermodynamic measurements that show that the two pentitols have identical sublimation energies. A rigid body normal coordinate analysis was performed on the atomic displacement parameters obtained at the four different temperatures. The translational and librational mean square deviations derived through this analysis were used in a quantum statistical approach to derive frequencies of the corresponding harmonic oscillators. The analysis showed a consistent vibrational model for all temperatures. The frequencies were subsequently used to calculate crystal entropies assuming an Einstein-type behavior. These calculations show that the crystal entropy of ribitol is 8 J K(-1) mol(-1) higher than the crystal entropy of xylitol, confirming that it is a difference in the entropy of the two compounds that causes the difference in their free energy. Our results presented in this Article show the potential to use X-ray diffraction data to obtain physicochemical properties of crystals. PMID:21663326

  10. Raman Based Process Monitor for Continuous Real-Time Analysis Of High Level Radioactive Waste Components

    International Nuclear Information System (INIS)

    A new monitoring system was developed at Pacific Northwest National Laboratory (PNNL) to quickly generate real-time data/analysis to facilitate a timely response to the dynamic characteristics of a radioactive high level waste stream. The developed process monitor features Raman and Coriolis/conductivity instrumentation configured for the remote monitoring, MatLab-based chemometric data processing, and comprehensive software for data acquisition/storage/archiving/display. The monitoring system is capable of simultaneously and continuously quantifying the levels of all the chemically significant anions within the waste stream including nitrate, nitrite, phosphate, carbonate, chromate, hydroxide, sulfate, and aluminate. The total sodium ion concentration was also determined independently by modeling inputs from on-line conductivity and density meters. In addition to the chemical information, this monitoring system provides immediate real-time data on the flow parameters, such as flow rate and temperature, and cumulative mass/volume of the retrieved waste stream. The components and analytical tools of the new process monitor can be tailored for a variety of complex mixtures in chemically harsh environments, such as pulp and paper processing liquids, electroplating solutions, and radioactive tank wastes. The developed monitoring system was tested for acceptability before it was deployed for use in Hanford Tank S-109 retrieval activities. The acceptance tests included perfvities. The acceptance tests included performance inspection of hardware, software, and chemometric data analysis to determine the expected measurement accuracy for the different chemical species that are encountered during S-109 retrieval. (authors)

  11. Effect of Different Levels of the Raw and Processed Vetch Seed (Vicia sativa on Broiler Performance

    Directory of Open Access Journals (Sweden)

    A.A. Saki

    2008-01-01

    Full Text Available An experiment was conducted to study the effects of different levels of raw and processed vetch (Vicia sativa seeds on broiler performance. The experiment was carried out in a Completely Randomized Design. Four hundred and seventy six day-old broilers of male Hubbard strain were used. Seven treatments (dietary contain 0, 10, 20 and 30% levels raw or processed vetch seeds were arranged by 4 replications and 17 broilers in each. The experiment period was 42 days and diets were isonitrogenous and isocaloric. Body weight gain was reduced significantly (p<0.05 by 20 and 30% raw and processed vetch seeds in comparison with control. No significantly difference was shown in body weight gain by 10% processed and 20% raw vetch seeds compared with control group. The similar reaction was found in feed conversion ratio between treatments with exception by 30% raw dietary vetch seed. The results of this study have shown that desirable performance was observed by 10% of common vetch seeds in broiler performance.

  12. Computationally based methodology for reengineering the high-level waste planning process at SRS

    International Nuclear Information System (INIS)

    The Savannah River Site (SRS) has started processing its legacy of 34 million gallons of high-level radioactive waste into its final disposable form. The SRS high-level waste (HLW) complex consists of 51 waste storage tanks, 3 evaporators, 6 waste treatment operations, and 2 waste disposal facilities. It is estimated that processing wastes to clean up all tanks will take 30+ yr of operation. Integrating all the highly interactive facility operations through the entire life cycle in an optimal fashion-while meeting all the budgetary, regulatory, and operational constraints and priorities-is a complex and challenging planning task. The waste complex operating plan for the entire time span is periodically published as an SRS report. A computationally based integrated methodology has been developed that has streamlined the planning process while showing how to run the operations at economically and operationally optimal conditions. The integrated computational model replaced a host of disconnected spreadsheet calculations and the analysts' trial-and-error solutions using various scenario choices. This paper presents the important features of the integrated computational methodology and highlights the parameters that are core components of the planning process

  13. Computationally based methodology for reengineering the high-level waste planning process at SRS

    Energy Technology Data Exchange (ETDEWEB)

    Paul, P.K.; Gregory, M.V.; Wells, M.N. [Westinghouse Savannah River Co., Aiken, SC (United States)

    1997-12-01

    The Savannah River Site (SRS) has started processing its legacy of 34 million gallons of high-level radioactive waste into its final disposable form. The SRS high-level waste (HLW) complex consists of 51 waste storage tanks, 3 evaporators, 6 waste treatment operations, and 2 waste disposal facilities. It is estimated that processing wastes to clean up all tanks will take 30+ yr of operation. Integrating all the highly interactive facility operations through the entire life cycle in an optimal fashion-while meeting all the budgetary, regulatory, and operational constraints and priorities-is a complex and challenging planning task. The waste complex operating plan for the entire time span is periodically published as an SRS report. A computationally based integrated methodology has been developed that has streamlined the planning process while showing how to run the operations at economically and operationally optimal conditions. The integrated computational model replaced a host of disconnected spreadsheet calculations and the analysts` trial-and-error solutions using various scenario choices. This paper presents the important features of the integrated computational methodology and highlights the parameters that are core components of the planning process.

  14. Quantum computation and the physical computation level of biological information processing

    CERN Document Server

    Castagnoli, Giuseppe

    2009-01-01

    On the basis of introspective analysis, we establish a crucial requirement for the physical computation basis of consciousness: it should allow processing a significant amount of information together at the same time. Classical computation does not satisfy the requirement. At the fundamental physical level, it is a network of two body interactions, each the input-output transformation of a universal Boolean gate. Thus, it cannot process together at the same time more than the three bit input of this gate - many such gates in parallel do not count since the information is not processed together. Quantum computation satisfies the requirement. At the light of our recent explanation of the speed up, quantum measurement of the solution of the problem is analogous to a many body interaction between the parts of a perfect classical machine, whose mechanical constraints represent the problem to be solved. The many body interaction satisfies all the constraints together at the same time, producing the solution in one ...

  15. Higher-level Innovization : A Case Study from Friction Stir Welding Process Optimization

    DEFF Research Database (Denmark)

    Bandaru, Sunith; Tutum, Cem Celal

    2011-01-01

    The task of finding crucial design interdependencies in the form of mathematical relationships (empirical or otherwise) in an engineering design problem using the Paretooptimal front is referred to as innovization. Past studies on the subject have limited themselves to a single front. In this paper we introduce the higher-level innovization task through an application of a manufacturing process simulation for the Friction Stir Welding (FSW) process where commonalities among two different Pareto-optimal fronts are analyzed. Multiple design rules are simultaneously deciphered from each front separately and compared. Important design aspects of the FSW problem are revealed in the process. The overall study aims at showing how some design principles can considerably ease the task of optimizing future enhancements to the design.

  16. Titanate waste forms for high level waste: an evaluation of materials and processes

    International Nuclear Information System (INIS)

    Emphasis in this titanate work is directed toward process simplicity as well as enhanced waste form stability. Titanate-based ceramics containing 25% by weight of waste oxides were prepared by a straightforward process involving direct batch contact of an acidic, high level liquid waste with a precursor powder, calcining to volatilize water and nitrates, and hot pressing (1250 to 12750) to produce a fully dense ceramic. The ceramic has a rutile matrix containing waste constituents distributed in three crystalline oxide phases - with structure types of the mineral analogues perovskite, zirconolite, hollandite - and in metallic phases present in minor amounts as metallic blebs. Addition of boron lowered processing temperatures for both hot pressing and atmospheric pressure sintering to the 925 to 9750C range. Leach rates were less than 10 ?g/day.cm2 for waste constituents and matrix attack was negligible at 2500C

  17. The Dow process for the solidification of low-level radioactive wastes from nuclear power plants

    International Nuclear Information System (INIS)

    This report summarizes the laboratory test program, pilot plant runs and field operating experience for solidification of low-level radioactive wastes from nuclear power plants with the Dow solidification process. Simulated wastes and radioactive wastes were converted into homogeneous, liquid-free monoliths. Pilot plant runs and field operating experience demonstrated that data generated in the laboratory could be extrapolated to 210 liter (55-gallon) drums and 1.4 m3 (50 ft.3) containers. Simulated waste and radioactive wastes produced in the operation of nuclear power plants were solidified and produced homogeneous, liquid-free monoliths which fulfill U.S. regulatory and Dow requirements. The advantages the Dow process offers the nuclear power industry are summarized. Several utilities in the United States have confirmed these advantages and are installing the Dow process in their plants

  18. Alternatives for high-level waste forms, containers, and container processing systems

    International Nuclear Information System (INIS)

    This study evaluates alternatives for high-level waste forms, containers, container processing systems, and onsite interim storage. Glass waste forms considered are cullet, marbles, gems, and monolithic glass. Small and large containers configured with several combinations of overpack confinement and shield casks are evaluated for these waste forms. Onsite interim storage concepts including canister storage building, bore holes, and storage pad were configured with various glass forms and canister alternatives. All favorable options include the monolithic glass production process as the waste form. Of the favorable options the unshielded 4- and 7-canister overpack options have the greatest technical assurance associated with their design concepts due to their process packaging and storage methods. These canisters are 0.68 m and 0.54 m in diameter respectively and 4.57 m tall. Life-cycle costs are not a discriminating factor in most cases, varying typically less than 15 percent

  19. Molecular dynamics study of monomer and dimer emission processes with high energy gas cluster ion impact

    International Nuclear Information System (INIS)

    The mechanism of the sputtering process by energetic large cluster ion impacts was studied using molecular dynamics (MD) simulations. MD simulations of Ar1000 clusters accelerated with 50 keV total energy impacting on a Si(100) target were performed with 50 trials at different impact points in order to improve the statistical reliance. From these MD simulations, a sputtering yield of about 20 Si atoms/impact was obtained. Additionally, Si clusters such as Si2, Si3, etc. were also found in the sputtered particles. The investigation of trajectories of sputtered Si1 and Si2 showed that initial coordinates of sputtered particles residing within a region corresponds to a crater-shaped hole caused by cluster impact. As for the sputtering of dimers, it is found that the emission of a pre-formed dimer (i.e. a pair of target atoms initially bound before the cluster impact) is a less probable event than dynamically formed dimers through multiple collisions of cluster and surface atoms. (author)

  20. Molecular characterization of dissolved organic matter through a desalination process by high resolution mass spectrometry.

    Science.gov (United States)

    Cortés-Francisco, Nuria; Caixach, Josep

    2013-09-01

    The effect of different water treatments such as ultrafiltration (UF) and reverse osmosis (RO) on dissolved organic matter (DOM) is still unknown. Electrospray ionization Fourier transform orbitrap mass spectrometry has been used to provide valuable information of marine DOM evolution through a desalination process on a molecular scale. In the present manuscript, the characterization of four real composite water samples from a desalination pilot plant installed in the coast of Barcelona (Spain) has been carried out. The sampling was performed on each point of the pilot plant: raw seawater (RSW), UF effluent, brine RO and permeate RO. The mass spectra of the different samples show several thousand peaks, however for the present screening study, only the mass range m/z 200-500 and the main signals in this mass range (relative intensities ?1%) have been considered. The analysis of RSW and UF samples reveal that there is little effect on DOM by the UF pilot. However, when the water is treated on the RO an important change on DOM has been observed. The recurring periodical patterns found in RSW and UF are lost in Permeate RO sample. Compounds with more aliphatic character, with higher H/C ratio (H/Cav 1.72) are present in the Permeate and some of them have been tentatively identified as fatty acids. PMID:23879562

  1. Molecular dynamics simulations of friction process between diamond-like carbon and Si-DLC films.

    Science.gov (United States)

    Lan, Huiqing; Kato, Takahisa

    2013-02-01

    Diamond-like carbon (DLC) films have been extensively studied over the past decades due to their unique combination of properties; in particular, silicon-doped DLC (Si-DLC) films are of significant interest for tribological effects, they had a very low friction coefficient and possessed the potential to improve wear performance in humid atmospheres and at higher temperatures. But many experimental results of the Si-DLC films showed that their tribological properties changed greatly on different silicon content. In the paper, molecular dynamics (MD) simulations were used to study microstructure of amorphous Si-DLC films and a sliding friction process between DLC and Si-DLC films on un-lubricated and oil-lubricated conditions respectively. The results show that silicon atoms are almost surrounded by carbon atoms in all Si-DLC films. The sp3/sp2 ratio in Si-DLC films increases with the increasing silicon content. After sliding, a transfer film between the DLC and Si-DLC films is formed on the un-lubricated condition. In contrast, a boundary lubrication layer is found on the oil-lubricated condition. Moreover, the friction forces on the un-lubricated condition are larger than those on the oil-lubricated condition. PMID:23646572

  2. Accelerated molecular dynamics force evaluation on graphics processing units for thermal conductivity calculations

    CERN Document Server

    Fan, Zheyong; Harju, Ari

    2012-01-01

    In this paper, we develop a highly efficient molecular dynamics code fully implemented on graphics processing units for thermal conductivity calculations using the Green-Kubo formula. We compare two different schemes for force evaluation, a previously used thread-scheme where a single thread is used for one particle and each thread calculates the total force for the corresponding particle, and a new block-scheme where a whole block is used for one particle and each thread in the block calculates one or several pair forces between the particle associated with the given block and its neighbor particle(s) associated with the given thread. For both schemes, two different classical potentials, namely, the Lennard-Jones potential and the rigid-ion potential are implemented. While the thread-scheme performs a little better for relatively large systems, the block-scheme performs much better for relatively small systems. The relative performance of the block-scheme over the thread-scheme also increases with the increa...

  3. Accelerated molecular dynamics force evaluation on graphics processing units for thermal conductivity calculations

    Science.gov (United States)

    Fan, Zheyong; Siro, Topi; Harju, Ari

    2013-05-01

    Thermal conductivity is a very important property of a material both for testing theoretical models and for designing better practical devices such as more efficient thermoelectrics, and accurate and efficient calculations of thermal conductivity are very desirable. In this paper, we develop a highly efficient molecular dynamics code fully implemented on graphics processing units for thermal conductivity calculations using the Green-Kubo formula. We compare two different schemes for force evaluation, a previously used thread-scheme, where a single thread is used for one particle and each thread calculates the total force for the corresponding particle, and a new block-scheme, where a whole block is used for one particle and each thread in the block calculates one or several pair forces between the particle associated with the given block and its neighbor particle(s) associated with the given thread. For both schemes, two different classical potentials, namely, the Lennard-Jones potential and the rigid-ion potential are implemented. While the thread-scheme performs a little better for relatively large systems, the block-scheme performs much better for relatively small systems. The relative performance of the block-scheme over the thread-scheme also increases with the increasing cutoff radius. We validate the implementation by calculating lattice thermal conductivities of solid argon and lead telluride. The efficiency of our code makes it very promising to study thermal conductivity properties of more complicated materials, especially, materials with interesting nanostructures.

  4. Uncovering Molecular Relaxation Processes with Nonlinear Spectroscopies in the Deep UV

    Science.gov (United States)

    West, Brantley Andrew

    Conical intersections mediate internal conversion dynamics that compete with even the fastest nuclear motions in molecular systems. Traditional kinetic models do not apply in this regime of commensurate electronic and nuclear motion because the surroundings do not maintain equilibrium throughout the relaxation process. This dissertation focuses on uncovering the physics associated with vibronic interactions at conical intersections. Of particular interest are coherent nuclear motions driven by steep excited state potential energy gradients. Technical advances have only recently made these dynamics accessible in many systems including DNA nucleobases and cyclic polyene molecules. Optical analogues of multidimensional NMR spectroscopies have recently yielded transformative insight in relaxation processes ranging from energy transfer in photosynthesis to bond making and breaking in liquids. Prior to the start of this research, such experiments had only been conducted at infrared and visible wavelengths. Applications in the ultraviolet were motivated by studies of numerous biological systems (e.g., DNA, proteins), but had been challenged by technical issues. The work presented in this dissertation combines pulse generation techniques developed in the optical physics community with spectroscopic techniques largely pioneered by physical chemists to implement two-dimensional ultraviolet spectroscopy (2DUV). This technique is applied at the shortest wavelengths and with the best signal-to-noise ratios reported to date. Sub-picosecond excited state deactivation processes provide photo stability to the DNA double helix. Vibrational energy transfer from the solute to surrounding solvent enables relaxation of the highly non-equilibrium ground state produced by fast internal conversion. In this dissertation, nonlinear spectroscopies carried out at cryogenic temperatures are used to uncover the particular nuclear modes in the solvent that primarily accept vibrational energy from the solute. These measurements additionally expose a competition between internal conversion and vibrational energy transfer onto the DNA backbone. Ring-opening reactions in cycloalkenes are one of the most fundamental reactions in organic chemistry. Traditional textbook understandings of these reactions conveniently hide the intricate physics that occurs prior to bond breaking. Sub-100-femtosecond internal conversion processes precede bond breaking in these systems. This dissertation directly monitors these dynamics in a derivative of cyclohexadiene, alpha-terpinene, and detects coherent wavepacket motions for the first time in solution.

  5. Quantitative immunocytochemistry at the ultrastructural level: a stereology-based approach to molecular nanomorphomics.

    Science.gov (United States)

    Mayhew, Terry M

    2015-04-01

    Biological systems span multiple levels of structural organisation from the macroscopic, via the microscopic, to the nanoscale. Therefore, comprehensive investigation of systems biology requires application of imaging modalities that reveal structure at multiple resolution scales. Nanomorphomics is the part of morphomics devoted to the systematic study of functional morphology at the nanoscale and an important element of its achievement is the combination of immunolabelling and transmission electron microscopy (TEM). The ultimate goal of quantitative immunocytochemistry is to estimate numbers of target molecules (usually peptides, proteins or protein complexes) in biological systems and to map their spatial distributions within them. Immunogold cytochemistry utilises target-specific affinity markers (primary antibodies) and visualisation aids (e.g., colloidal gold particles or silver-enhanced nanogold particles) to detect and localise target molecules at high resolution in intact cells and tissues. In the case of post-embedding labelling of ultrathin sections for TEM, targets are localised as a countable digital readout by using colloidal gold particles. The readout comprises a spatial distribution of gold particles across the section and within the context of biological ultrastructure. The observed distribution across structural compartments (whether volume- or surface-occupying) represents both specific and non-specific labelling; an assessment by eye alone as to whether the distribution is random or non-random is not always possible. This review presents a coherent set of quantitative methods for testing whether target molecules exhibit preferential and specific labelling of compartments and for mapping the same targets in two or more groups of cells as their TEM immunogold-labelling patterns alter after experimental manipulation. The set also includes methods for quantifying colocalisation in multiple-labelling experiments and mapping absolute numbers of colloidal gold particles across compartments at specific positions within cells having a point-like inclusion (e.g., centrosome, nucleolus) and a definable vertical axis. Although developed for quantifying colloidal gold particles, the same methods can in principle be used to quantify other electron-dense punctate nanoparticles, including quantum dots. PMID:25403623

  6. International Workshop on Dynamics and control of atomic and molecular processes induced by intense ultrashort pulses

    International Nuclear Information System (INIS)

    Complete text of publication follows. The workshop was organized by the Institute of Nuclear Research of the Hungarian Academy of Sciences (Atomki) Debrecen, Hungary from 27th of September till 30th of September 2011. The sponsor of the workshop was the COST Action CM0702 Chemistry with Ultrashort Pulses and Free-Electron Lasers: Looking for Control Strategies through Exact Computations (CUSPFEL). The workshop focused on all aspects of processes and phenomena stimulated by intense ultrashort pulses. The aim of the interdisciplinary workshop was to bring together senior scientists as well as students from countries working in diverse subfields closely connected to the common underlying theme of atomic and molecular processes induced by intense ultrashort pulses. Although the topic of the workshop was mainly belong to the theoretical physics, prominent representatives of the experimental physics from various Hungarian institutes (Budapest, Szeged, Pecs) attended on the workshop. The workshop contained only invited talks. The length of the oral presentations was 30 minutes. The conference program included 25 talks in 9 sessions. The sections of the program were: 1) Bio-molecules, 2) Control, 3) Strong Field, 4) Dissociation, 5) Photoelectron, 6) Ultrashort, 7) Scattering, 8) Ultrafast, 9) Control II. During the workshop we had 32 registered participants from 9 countries (Austria, Croatia, France, Germany, Hungary, Romania, Spain, Switzerland, and UK). Acknowledgements. T Switzerland, and UK). Acknowledgements. The organizers would like to acknowledge the excellent cooperation of all contributors providing high standard lectures to ensure the success of the workshop. The organizers express their thanks for the support of the sponsors of the conference.

  7. The role of atomic and molecular collision processes in plasmas - and vice versa

    Science.gov (United States)

    Gans, Timo

    2008-10-01

    A broad base of accurate data of atomic and molecular collision processes is essential for reliable modelling, simulation, and diagnostics of plasmas. This is particularly important for plasmas at elevated pressures close to atmosphere. This regime attracts rapidly growing attention due to both - promising innovative technological applications as well as new fundamental scientific phenomena. The collision dominated environment and decreasing dimensions down to microscale plasmas with extremely high surface to volume ratios significantly increase the demand for collisional deactivation and surface interaction processes. Cross sections for collisional deactivation can be determined from the effective lifetime of excited states. Direct excitation using short pulse laser systems are most reliable however limited by optical selection rules and available photon energies. Recently improved understanding of the dynamics of electron impact excitation in radio-frequency discharges allows alternative strategies using space and phase resolved optical emission spectroscopy measurements coupled with careful modelling of the population dynamics of excited states. This method based on electron impact excitation is not limited by optical selection rules and also provides access to high energetic electronic states which are not accessible with common laser systems. Data for surface interactions is inherently delicate since it strongly depends on surface properties such as coverage and temperature. Nevertheless, reliable data for recombination of radicals and metastable states, and coefficients for secondary electron emission are highly desirable for consistent modelling and simulation. An alternative approach is the active implementation of experimentally measured surface sensitive parameters such as atomic radical densities and excitation structures caused by secondary electrons. These experimentally accessible quantities can be used as fixed input parameters in improved self-consistent modelling.

  8. Reactive molecular dynamics simulations of switching processes of azobenzene-based monolayer on surface

    Science.gov (United States)

    Tian, Ziqi; Wen, Jin; Ma, Jing

    2013-07-01

    It is a challenge to simulate the switching process of functional self-assembled monolayers (SAMs) on metal surfaces, since the systems consist of thousands of atoms and the switching is triggered by quantum-mechanical events. Herein a molecular dynamics simulation with a reactive rotation potential of N=N bond is implemented to investigate the dynamic conformational changes and packing effects on the stimuli-responsive isomerization of the terminally thiol functionalized azobiphenyls (AZOs), which are bound on the Au(111) surface. To, respectively, distinguish the time evolutions that start from cis and trans initial configurations, two different functions are established to model the potential energy curves for cis-to-trans and trans-to-cis transitions, instead of the only one cosine function used in the conventional non-reactive force fields. In order to simulate the conformation transitions of the AZO film on surface, a random switching function, depending on the N=N twisting angle, is constructed to consider both forward and backward cis/trans isomerization events and to trigger the reaction by changing the N atom types automatically. The factors that will influence the isomerization process, including the choice of ensembles and thermostat algorithms, the time intervals separating each switching, and the forms of the switching function, are systematically tested. Most AZO molecules switch from the cis to trans configuration with a coverage of 5.76 × 10-6 mol/m2 on a picosecond time scale, and a low coverage might make the switching irreversible, which is in agreement with the experiments.

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

    OpenAIRE

    Cardinale, Jean A.

    2011-01-01

    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 m...

  10. ENVIROSUITE: USING STATE-OF-THE-ART SYNCHROTRON TECHNIQUES TO UNDERSTAND ENVIRONMENTAL REMEDIATION SCIENCE ISSUES AT THE MOLECULAR LEVEL

    International Nuclear Information System (INIS)

    Although DOE's Environmental Management program has made steady progress in cleaning up environmental legacies throughout the DOE complex, there are still significant remediation issues that remain to be solved. For example, DOE faces difficult challenges related to potential mobilization of radionuclides (e.g., actinides) and other hazardous contaminants in soils, removal and final treatment of high-level waste and residuals from leaking tanks, and the long-term stewardship of remediated sites and engineered disposal facilities, to name just a few. In some cases, new technologies and technology applications will be required based on current engineering expertise. In others, however, basic scientific research is needed to understand the mechanisms of how contaminants behave under specific conditions and how they interact with the environment, from which new engineering solutions can emerge. At Brookhaven National Laboratory (BNL) and Stony Brook University, scientists have teamed to use state-of-the-art synchrotron techniques to help understand the basic interactions of contaminants in the environment. Much of this work is conducted at the BNL National Synchrotron Light Source (NSLS), which is a user facility that provides high energy X-ray and ultraviolet photon beams to facilitate the examination of contaminants and materials at the molecular level. These studies allow us to determine how chemical speciation and structure control important parameters such as solubilntrol important parameters such as solubility, which in turn drive critical performance characteristics such as leaching. In one study for example, we are examining the effects of microbial activity on actinide contaminants under conditions anticipated at the Waste Isolation Pilot Plant. One possible outcome of this research is the identification of specific microbes that can trap uranium or other contaminants within the intracellular structure and help mitigate mobility. In another study, we are exploring the interaction of contaminants with soil and plant roots to better understand the mechanisms responsible for uptake. This effort will lead to improvements in phytoremediation, an innovative and cost-effective approach to the cleanup of large volumes of soil with low concentrations of contaminants. In a third effort, we are investigating molecular interactions of contaminants in high-level waste tanks with potential grouting materials for remediation of the West Valley, NY site to assess their suitability and long-term performance

  11. Técnicas de caracterização para investigar interações no nível molecular em filmes de Langmuir e Langmuir-Blodgett (LB) / Characterization techniques to investigate molecular-level interactions in Langmuir and Langmuir-Blodgett (LB) films

    Scientific Electronic Library Online (English)

    Marystela, Ferreira; Wilker, Caetano; Rosangela, Itri; Marcel, Tabak; Osvaldo N., Oliveira Jr..

    2005-06-01

    Full Text Available [...] Abstract in english This paper discusses fundamental concepts for the characterization of Langmuir monolayers and Langmuir-Blodgett (LB) films, with emphasis on investigations of material properties at the molecular level. By way of illustration, results for phospholipid monolayers interacting with the drug dipyridamol [...] e are highlighted. These results were obtained with several techniques, including in situ grazing incidence X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, fluorescence microscopy, in addition to surface pressure and surface potential isotherms. Also mentioned are the difficulties in producing Langmuir and LB films from macromolecules, and how molecular-level interactions in mixed polymer LB films can be exploited in sensors.

  12. High-temperature process in partitioning of high-level waste

    International Nuclear Information System (INIS)

    Now, 37 power reactors are in operation in Japan, and the total power generation capacity reached 30 million kW. There are two ways for the spent fuel taken out of reactors, to store it or to reprocess it for recovering and recycling nuclear fission substances and fertile materials. Japan selected the latter way, and has advanced its development. When nuclear fuel cycle is completed by reprocessing spent fuel, it is one of the most important subjects to establish the treatment and disposal methods for high level radioactive wastes being generated. At present, it is decided that the high level waste liquid generated by fuel reprocessing is all solidified with glass and the formation disposal of the solids is carried out. If group partition which is considered as a future technology in nuclear fuel cycle is established, the nuclides having long half life in high level radioactive wastes can attain the more rational disposal by annihilation disposal, and by the effective utilization of recovered useful metals and useful radiation sources, high level radioactive wastes can be considered as resources. High level radioactive wastes, annihilation disposal, wet and dry group partition processes are described. (K.I.)

  13. Encapsulation of lycopene using spray-drying and molecular inclusion processes

    Scientific Electronic Library Online (English)

    Itaciara Larroza, Nunes; Adriana Zerlotti, Mercadante.

    2007-09-01

    Full Text Available Técnicas de encapsulamento, como "spray-drying" e formação de complexos por inclusão com ciclodextrinas, vêm sendo avaliadas para viabilizar a adição de carotenóides em sistemas hidrofílicos e aumentar a sua estabilidade durante o processamento e estocagem. Portanto, o objetivo do presente trabalho [...] foi obter licopeno encapsulado na forma de pó, utilizando processos de "spray-drying" ou de inclusão molecular com beta -ciclodextrina (CD) seguido de liofilização. A eficiência do encapsulamento utilizando "spray-drying" variou de 94 a 96% e o rendimento médio foi de 51%, com as microcápsulas apresentando indentações superficiais, porém sem falhas ou aberturas na superfície. A formação de complexo licopeno- beta -CD ocorreu apenas quando utilizada razão molar de 1:4, e estruturas irregulares de diferentes tamanhos que eventualmente formaram agregados, similares às da beta -CD, foram observadas após liofilização. O licopeno não complexado neste processo ficou em torno de 50%. A pureza do licopeno (% área do all-trans-licopeno) aumentou de 96,4 para 98,1% após o encapsulamento, enquanto que a pureza do licopeno diminuiu de 97,7 para 91,3% após complexação e liofilização. Os dois processos de secagem resultaram em pós rosa claro, secos e com bom fluxo. Abstract in english This study aimed to obtain encapsulated lycopene in a powder form, using either spray-drying or molecular inclusion with beta -cyclodextrin ( beta -CD) followed by freeze-drying. The encapsulation efficiency using spray-drying ranged from 94 to 96%, with an average yield of 51%, with microcapsules s [...] howing superficial indentations and lack of cracks and breakages. Lycopene- beta -CD complexes were only formed at a molar ratio of 1:4, and irregular structures of different sizes that eventually formed aggregates, similar to those of beta -CD, were observed after freeze-drying. About 50% of the initial lycopene did not form complexes with beta -CD. Lycopene purity increased from 96.4 to 98.1% after spray-drying, whereas lycopene purity decreased from 97.7 to 91.3% after complex formation and freeze-drying. Both the drying processes yielded pale-pink, dry, free-flowing powders.

  14. Encapsulation of lycopene using spray-drying and molecular inclusion processes

    Directory of Open Access Journals (Sweden)

    Itaciara Larroza Nunes

    2007-09-01

    Full Text Available This study aimed to obtain encapsulated lycopene in a powder form, using either spray-drying or molecular inclusion with beta -cyclodextrin ( beta -CD followed by freeze-drying. The encapsulation efficiency using spray-drying ranged from 94 to 96%, with an average yield of 51%, with microcapsules showing superficial indentations and lack of cracks and breakages. Lycopene- beta -CD complexes were only formed at a molar ratio of 1:4, and irregular structures of different sizes that eventually formed aggregates, similar to those of beta -CD, were observed after freeze-drying. About 50% of the initial lycopene did not form complexes with beta -CD. Lycopene purity increased from 96.4 to 98.1% after spray-drying, whereas lycopene purity decreased from 97.7 to 91.3% after complex formation and freeze-drying. Both the drying processes yielded pale-pink, dry, free-flowing powders.Técnicas de encapsulamento, como "spray-drying" e formação de complexos por inclusão com ciclodextrinas, vêm sendo avaliadas para viabilizar a adição de carotenóides em sistemas hidrofílicos e aumentar a sua estabilidade durante o processamento e estocagem. Portanto, o objetivo do presente trabalho foi obter licopeno encapsulado na forma de pó, utilizando processos de "spray-drying" ou de inclusão molecular com beta -ciclodextrina (CD seguido de liofilização. A eficiência do encapsulamento utilizando "spray-drying" variou de 94 a 96% e o rendimento médio foi de 51%, com as microcápsulas apresentando indentações superficiais, porém sem falhas ou aberturas na superfície. A formação de complexo licopeno- beta -CD ocorreu apenas quando utilizada razão molar de 1:4, e estruturas irregulares de diferentes tamanhos que eventualmente formaram agregados, similares às da beta -CD, foram observadas após liofilização. O licopeno não complexado neste processo ficou em torno de 50%. A pureza do licopeno (% área do all-trans-licopeno aumentou de 96,4 para 98,1% após o encapsulamento, enquanto que a pureza do licopeno diminuiu de 97,7 para 91,3% após complexação e liofilização. Os dois processos de secagem resultaram em pós rosa claro, secos e com bom fluxo.

  15. A Wafer Level Vacuum Encapsulated Capacitive Accelerometer Fabricated in an Unmodified Commercial MEMS Process

    Directory of Open Access Journals (Sweden)

    Adel Merdassi

    2015-03-01

    Full Text Available We present the design and fabrication of a single axis low noise accelerometer in an unmodified commercial MicroElectroMechanical Systems (MEMS process. The new microfabrication process, MEMS Integrated Design for Inertial Sensors (MIDIS, introduced by Teledyne DALSA Inc. allows wafer level vacuum encapsulation at 10 milliTorr which provides a high Quality factor and reduces noise interference on the MEMS sensor devices. The MIDIS process is based on high aspect ratio bulk micromachining of single-crystal silicon layer that is vacuum encapsulated between two other silicon handle wafers. The process includes sealed Through Silicon Vias (TSVs for compact design and flip-chip integration with signal processing circuits. The proposed accelerometer design is sensitive to single-axis in-plane acceleration and uses a differential capacitance measurement. Over ±1 g measurement range, the measured sensitivity was 1fF/g. The accelerometer system was designed to provide a detection resolution of 33 milli-g over the operational range of ±100 g.

  16. Best Practices to Achieve CMMI Level 2 Configuration Management Process Area through VSS tool

    Directory of Open Access Journals (Sweden)

    Prerna Gupta

    2011-05-01

    Full Text Available Over the past years, the capability maturity model (CMM and capability maturity model integration (CMMI have been broadly used for assessing organizational maturity and process capability throughout the world. However, the rapid pace of change in information technology has caused increasing frustration to the heavyweight plans, specifications, and other documentation imposed by contractual inertia and maturity model compliance criteria. In light of that, configuration management methodologies have been adopted to tackle this challenge. The aim of our paper is to present mapping between CMMI and one of the SCM tool VSS. It shows how VSS addresses the Configuration Management Process Areas of CMMI and help in achieving all the goals which are defined at CMMI level 2 Configuration process areas. This is useful for organizations that have their plan-driven process based on the CMMI model and are planning to improve its processes toward agility or to help organizations to define a new project management framework based on both CMMI and configuration practices.

  17. Similarities and Differences between Working Memory and Long-Term Memory: Evidence from the Levels-of-Processing Span Task

    Science.gov (United States)

    Rose, Nathan S.; Myerson, Joel; Roediger, Henry L., III; Hale, Sandra

    2010-01-01

    Two experiments compared the effects of depth of processing on working memory (WM) and long-term memory (LTM) using a levels-of-processing (LOP) span task, a newly developed WM span procedure that involves processing to-be-remembered words based on their visual, phonological, or semantic characteristics. Depth of processing had minimal effect on…

  18. State-of-the-Art Article: The Role and Importance of Lower-Level Processes in Second Language Reading

    Science.gov (United States)

    Nassaji, Hossein

    2014-01-01

    This article examines current research on the role and importance of lower-level processes in second language (L2) reading. The focus is on word recognition and its subcomponent processes, including various phonological and orthographic processes. Issues related to syntactic and semantic processes and their relationship with word recognition are…

  19. Initial Molecular-Level Response to Artificial Selection for Increased Aerobic Metabolism Occurs Primarily through Changes in Gene Expression.

    Science.gov (United States)

    Konczal, Mateusz; Babik, Wies?aw; Radwan, Jacek; Sadowska, Edyta T; Koteja, Pawe?

    2015-06-01

    Experimental evolution combined with genome or transcriptome resequencing (Evolve and Resequence) represents a promising approach for advancing our understanding of the genetic basis of adaptation. Here, we applied this strategy to investigate the effect of selection on a complex trait in lines derived from a natural population of a small mammal. We analyzed the liver and heart transcriptomes of bank voles (Myodes [=Clethrionomys] glareolus) that had been selected for increased aerobic metabolism. The organs were sampled from 13th generation voles; at that point, the voles from four replicate selected lines had 48% higher maximum rates of oxygen consumption than those from four control lines. At the molecular level, the response to selection was primarily observed in gene expression: Over 300 genes were found to be differentially expressed between the selected and control lines and the transcriptome-wide pattern of expression distinguished selected lines from controls. No evidence for selection-driven changes of allele frequencies at coding sites was found: No single nucleotide polymorphism (SNP) changed frequency more than expected under drift alone and frequency changes aggregated over all SNPs did not separate selected and control lines. Nevertheless, among genes which showed highest differentiation in allele frequencies between selected and control lines we identified, using information about gene functions and the biology of the selected phenotype, plausible targets of selection; these genes, together with those identified in expression analysis, have been prioritized for further studies. Because our selection lines were derived from a natural population, the amount and the spectrum of variation available for selection probably closely approximated that typically found in populations of small mammals. Therefore, our results are relevant to the understanding of the molecular basis of complex adaptations occurring in natural vertebrate populations. PMID:25739734

  20. Complete NLO QCD corrections for tree level ? F = 2 FCNC processes: colourless gauge bosons and scalars

    Science.gov (United States)

    Buras, Andrzej J.; Girrbach, Jennifer

    2012-03-01

    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 ? F = 2 processes mediated by heavy colourless gauge bosons and scalars. Such contributions can be present at the fundamental level when the GIM mechanism is absent as in numerous Z' models, gauged flavour models with new very 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 Minimal Flavour Violation of which Two-Higgs Doublet models with and without supersymmetry are the best known examples. In models containing vectorial heavy fermions that mix with the standard chiral quarks and models in which Z 0 and SM neutral Higgs H 0 mix with new heavy gauge bosons and scalars in the process of electroweak symmetry breaking also tree-level Z 0 and SM neutral Higgs H 0 contributions to ? F = 2 processes are possible. In all these extensions new local operators absent in the SM are generated having Wilson coefficients that are generally much stronger affected by renormalization group QCD effects than it is the case of the SM operators. The new aspect of our work is the calculation of O( ? s ) corrections to matching conditions for the Wilson coefficients of the contributing operators in the {text{NDR}} - overline {text{MS}} scheme that can be used in all models listed above. This allows to reduce certain unphysical scale and renormalization scheme dependences in the existing NLO calculations. We show explicitly how our results can be combined with the analytic formulae for the so-called P_i^a QCD factors that include both hadronic matrix elements of contributing operators and renormalization group evolution from high energy to low energy scales. For the masses of heavy gauge bosons and scalars O(1) TeV the remaining unphysical scale dependences for the mixing amplitudes M 12 are reduced typically from 10 - 25%, depending on the operator considered, down to 1 - 2%.

  1. Roles of atomic and molecular processes in fusion plasma researches. From the cradle (plasma production) to the grave (after-burning)

    International Nuclear Information System (INIS)

    This short lecture given at RIKEN Winter School on Atomic and Molecular Processes in Tsunan, Niigata, has described some crucial roles of atomic and molecular (AM) physics in magnetic fusion plasma research. Particular importance has been stressed of collision processes involving species in the excited states in fusion plasmas, especially in divertor and edge plasmas. (author)

  2. Modeling Efforts to Aid in the Determination of Process Enrichment Levels for Identifying Potential Material Diversion

    International Nuclear Information System (INIS)

    Efforts have been under way at Lawrence Livermore National Laboratory (LLNL) to develop detailed analytical models that simulate enrichment and conversion facilities for the purpose of aiding in the detection of material diversion as part of an overall safeguards strategy. These models could be used to confirm proper accountability of the nuclear materials at facilities worldwide. Operation of an enrichment process for manufacturing commercial reactor fuel presents proliferation concerns including both diversion and the potential for further enrichment to make weapons grade material. While inspections of foreign reprocessing facilities by the International Atomic Energy Agency (IAEA) are meant to ensure that such diversion is not occurring, it must be verified that such diversion is not taking place through both examination of the facility and taking specific measurements such as the radiation fields outside of various process lines. Our current effort is developing algorithms that would be incorporated into the current process models that would provide both neutron and gamma radiation fields outside any process line for the purpose of to determining the most effective locations for placing in-plant monitoring equipment. These algorithms, while providing dose and spectral information, could also be designed to provide detector responses that could be physically measured at various points on the process line. Such information could be used to optimize detector locationould be used to optimize detector locations in support of real-time on-site monitoring to determine the enrichment levels within a process stream. The results of parametric analyses to establish expected variations for several different process streams and configurations are presented. Based upon these results, the capability of a sodium iodide (NaI(Tl)), high-purity germanium (HPGe), or neutron detection system is being investigated from the standpoint of their viability in quantitatively measuring and discerning the enrichment and potential throughput variations thereof. The benefits and issues associated with both passive and active interrogation measurement techniques are also discussed

  3. An Efficient Liver-Segmentation System Based on a Level-Set Method and Consequent Processes

    Directory of Open Access Journals (Sweden)

    Walita Narkbuakaew

    2014-10-01

    Full Text Available This paper presents an efficient liver-segmentation system developed by combining three ideas under the operations of a level-set method and consequent processes. First, an effective initial process creates mask and seed regions. The mask regions assist in prevention of leakage regions due to an overlap of gray-intensities between liver and another soft-tissue around ribs and verte-brae. The seed regions are allocated inside the liver to measure statistical values of its gray-intensities. Second, we introduce liver-corrective images to represent statistical regions of the liver and preserve edge information. These images help a geodesic active contour (GAC to move without obstruction from high level of image noises. Lastly, the computation time in a level-set based on reaction-diffusion evolution and the GAC method is reduced by using a concept of multi-resolution. We applied the proposed system to 40 sets of 3D CT-liver data, which were acquired from four patients (10 different sets per patient by a 4D-CT imaging system. The segmentation results showed 86.38% ± 4.26% (DSC: 91.38% ± 2.99% of similarities to outlines of manual delineation provided by a radiologist. Meanwhile, the results of liver segmentation only using edge images presented 79.17% ± 5.15% or statistical regions showed 74.04% ± 9.77% of similarities.

  4. The glass-ceramic processing flowsheet for ICPP high-level waste: Status report

    International Nuclear Information System (INIS)

    High-level liquid wastes (HLLW) are generated at the Idaho Chemical Processing Plant (ICPP) from the reprocessing of irradiated government nuclear fuels. The basic types of fuel reprocessed at the ICPP include those which are clad in aluminum, stainless steel, and zirconium. The HLLW is then solidified bed calciner at a temperature of 500 degrees C in the New Waste Calcining Facility (NWCF). The calcined waste is stored near-surface in concrete encased stainless steel bins. A glass-ceramic waste form is being developed for immobilizing calcined high-level wastes (HLLW) prior to final disposal. Development work at the ICPP has included the formulation of experimental glass-ceramic waste forms to immobilize the calcined HLW, and the conceptualization of a process to produce the waste forms. Research has shown that a glass-ceramic waste form, with leaching properties comparable to a glass, could result in about 60% less immobilized waste volume as compared to a vitrified waste form. A conceptual process to produce a glass-ceramic waste form meeting the current preliminary regulatory durability requirements has been identified

  5. Actinide partitioning from high level liquid waste using the Diamex process

    International Nuclear Information System (INIS)

    The removal of long-lived radionuclides, which belong to the so-called minor actinides elements, neptunium, americium and curium, from the high level nuclear wastes separated during the reprocessing of the irradiated nuclear fuels in order to transmute them into short-lived nuclides, can substantially decrease the potential hazards associated with the management of these nuclear wastes. In order to separate minor actinides from high-level liquid wastes (HLLW), a liquid-liquid extraction process was considered, based on the use of diamide molecules, which display the property of being totally burnable, thus they do not generate secondary solid wastes. The main extracting properties of dimethyldibutyltetradecylmalonamide (DMDBTDMA), the diamide selected for the development of the DIAMEX process, are briefly described in this paper. Hot tests of the DIAMEX process (using DMDBTDMA) related to the treatment of an mixed oxide fuels (MOX) type HLLW, were successfully performed. The minor actinide decontamination factors of the HLLW obtained were encouraging. The main results of these tests are presented and discussed in this paper. (authors). 9 refs., 2 figs., 7 tabs

  6. Tank waste remediation system high-level waste feed processability assessment report

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, S.L. [Westinghouse Hanford Co., Richland, WA (United States); Kim, D.S. [Pacific Northwest Lab., Richland, WA (United States)

    1994-12-01

    This study evaluates the effect of feed composition on the performance of the high-level vitrification process. It is assumed in this study that the tank wastes are retrieved and blended by tank farms, producing 12 different blends from the single-shell tank farms, two blends of double-shell tank waste, and a separately defined all-tank blend. This blending scenario was chosen only for evaluating the impact of composition on the volume of high- level waste glass produced. Special glass compositions were formulated for each waste blend based on glass property models and the properties of similar glasses. These glasses were formulated to meet the applicable viscosity, electrical conductivity, and liquidus temperature constraints for the identified candidate melters. Candidate melters in this study include the low-temperature stirred melter, which operates at 1050{degrees}C; the reference Hanford Waste Vitrification Plant liquid-fed ceramic melter, which operates at 1150{degrees}C; and the high-temperature, joule-heated melter and the cold-crucible melter, which operate over a temperature range of 1150{degrees}C to 1400{degrees}C. In the most conservative case, it is estimated that 61,000 MT of glass will be produced if the Site`s high-level wastes are retrieved by tank farms and processed in the reference joule-heated melter. If an all-tank blend was processed under the same conditions, the reference melter would produce 21,250 MT of glass. If cross-tank blending were used, it is anticipated that $2.0 billion could be saved in repository disposal costs (based on an average disposal cost of $217,000 per canister) by blending the S, SX, B, and T Tank Farm wastes with other wastes prior to vitrification. General blending among all the tank farms is expected to produce great potential benefit.

  7. Tank waste remediation system high-level waste feed processability assessment report

    International Nuclear Information System (INIS)

    This study evaluates the effect of feed composition on the performance of the high-level vitrification process. It is assumed in this study that the tank wastes are retrieved and blended by tank farms, producing 12 different blends from the single-shell tank farms, two blends of double-shell tank waste, and a separately defined all-tank blend. This blending scenario was chosen only for evaluating the impact of composition on the volume of high- level waste glass produced. Special glass compositions were formulated for each waste blend based on glass property models and the properties of similar glasses. These glasses were formulated to meet the applicable viscosity, electrical conductivity, and liquidus temperature constraints for the identified candidate melters. Candidate melters in this study include the low-temperature stirred melter, which operates at 1050 degrees C; the reference Hanford Waste Vitrification Plant liquid-fed ceramic melter, which operates at 1150 degrees C; and the high-temperature, joule-heated melter and the cold-crucible melter, which operate over a temperature range of 1150 degrees C to 1400 degrees C. In the most conservative case, it is estimated that 61,000 MT of glass will be produced if the Site's high-level wastes are retrieved by tank farms and processed in the reference joule-heated melter. If an all-tank blend was processed under the same conditions, the reference melter would produce 21,250 MT of glass. If cross-tank blending were used, it is anticipated that $2.0 billion could be saved in repository disposal costs (based on an average disposal cost of $217,000 per canister) by blending the S, SX, B, and T Tank Farm wastes with other wastes prior to vitrification. General blending among all the tank farms is expected to produce great potential benefit

  8. Pyrochemical treatment of Idaho Chemical Processing Plant high-level waste calcine

    International Nuclear Information System (INIS)

    The Idaho Chemical Processing Plant (ICPP), located at the Idaho National Engineering Laboratory (INEL), has reprocessed irradiated nuclear fuels for the US Department of Energy (DOE) since 1951 to recover uranium, krypton-85, and isolated fission products for interim treatment and immobilization. The acidic radioactive high-level liquid waste (HLLW) is routinely stored in stainless steel tanks and then, since 1963, calcined to form a dry granular solid. The resulting high-level waste (HLW) calcine is stored in seismically hardened stainless steel bins that are housed in underground concrete vaults. A research and development program has been established to determine the feasibility of treating ICPP HLW calcine using pyrochemical technology.This technology is described

  9. Work in process level definition: a method based on computer simulation and electre tri

    Scientific Electronic Library Online (English)

    Isaac, Pergher; Guilherme Luís Roehe, Vaccaro.

    2014-09-01

    Full Text Available This paper proposes a method for defining the levels of work in progress (WIP) in productive environments managed by constant work in process (CONWIP) policies. The proposed method combines the approaches of Computer Simulation and Electre TRI to support estimation of the adequate level of WIP and i [...] s presented in eighteen steps. The paper also presents an application example, performed on a metalworking company. The research method is based on Computer Simulation, supported by quantitative data analysis. The main contribution of the paper is its provision of a structured way to define inventories according to demand. With this method, the authors hope to contribute to the establishment of better capacity plans in production environments.

  10. Waste form development for immobilization of high level waste calcine at the Idaho Chemical Processing Plant

    International Nuclear Information System (INIS)

    Since 1963 the high-level liquid waste generated at the Idaho Chemical Processing Plant (ICPP) is routinely solidified into granular calcined high level waste (HLW). A research and development program at ICPP is currently developing waste forms for immobilization of the HLW that is stored onsite. One of the waste forms that is being developed is a durable glass-ceramic, a form of material consisting of crystalline phases and a glassy matrix. The glass-ceramic waste form is a promising option because it can potentially reduce HLW volume significantly compared to glass waste forms while maintaining similar leach rates. In this paper the impact of reactants (Ti and Al) and frit additive (B2O3) on leach rates, microstructure and phase composition of glass-ceramic waste forms is discussed

  11. US and Russian innovative technologies to process low-level liquid radioactive wastes: The Murmansk initiative

    International Nuclear Information System (INIS)

    This paper documents the status of the technical design for the upgrade and expansion to the existing Low-level Liquid Radioactive Waste (LLLRW) treatment facility in Murmansk, the Russian Federation. This facility, owned by the Ministry of Transportation and operated by the Russian company RTP Atomflot in Murmansk, Russia, has been used by the Murmansk Shipping Company (MSCo) to process low-level liquid radioactive waste generated by the operation of its civilian icebreaker fleet. The purpose of the new design is to enable Russia to permanently cease the disposal at sea of LLLRW in the Arctic, and to treat liquid waste and high saline solutions from both the Civil and North Navy Fleet operations and decommissioning activities. Innovative treatments are to be used in the plant which are discussed in this paper

  12. A hazard and probabilistic safety analysis of a high-level waste transfer process

    International Nuclear Information System (INIS)

    This paper describes a safety analysis of a transfer process for high-level radioactive and toxic waste. The analysis began with a hazard assessment that used elements of What If, Checklist, Failure Modes and Effects Analysis, and Hazards and Operability Study (HAZOP) techniques to identify and rough-in accident sequences. Based on this preliminary analysis, the most significant accident sequences were developed further using event trees. Quantitative frequency estimates for the accident sequences were based on operational data taken from the historical record of the site where the process is performed. Several modeling challenges were encountered in the course of the study. These included linked initiating and accident progression events, fire propagation modeling, accounting for administrative control violations, and handling mission-phase effects

  13. Organization of the two-level memory in the image processing system on scanning measuring projectors

    International Nuclear Information System (INIS)

    Discussed are the problems of improving the efficiency of the system for processing pictures taken in bubble chambers with the use of scanning measuring projectors. The system comprises 20 to 30 pro ectors linked with the ICL-1903A computer provided with a mainframe memory, 64 kilobytes in size. Because of the insufficient size of a mainframe memory, a part of the programs and data is located in a second-level memory, i.e. in an external memory. The analytical model described herein is used to analyze the effect of the memory organization on the characteristics of the system. It is shown that organization of pure procedures and introduction of the centralized control of the tWo-leVel memory result in substantial improvement of the efficiency of the picture processing system

  14. Evaluation of a processing technique for immobilization of low-level waste

    International Nuclear Information System (INIS)

    A commercially available joule-heated glass furnace system is currently being evaluated at Mound as a means of processing low-level radioactive waste typically found in light water reactor facilities. This evaluation has been primarily concerned with determining the effectiveness of the processing technique in the areas of volume reduction and immobilization. The first phase of the evaluation consisted of a series of nonradioactive experiments to determine the combustion efficiency of the furnace and chemical durability of the glass for several waste types deemed representative of power plant effluent streams. Upon completion of this work, radioactive spiked experiments were initiated which will provide, when completed, a comprehensive mass balance and establish volatility trends for several predominant radioisotopes. 1 reference

  15. Development of new treatment process for low level radioactive waste at Tokai reprocessing plant

    International Nuclear Information System (INIS)

    The Low-level radioactive Waste Treatment Facility (LWTF) was constructed at the Tokai Reprocessing Plant (TRP) and cold testing has been carried out since 2006. The waste which will be treated in the LWTF is combustible/incombustible solid waste and liquid waste. In the LWTF, the combustible/incombustible solid waste will be incinerated. The liquid waste will be treated by a radio-nuclides removal process and subsequently solidified in cement. This report describes the essential technologies of the LWTF and results of R and D work for the nitrate-ion decomposition technology for the liquid waste. (author)

  16. Advantages presented by the industrial introduction of information processing in the centralised surveillance of radiation levels

    International Nuclear Information System (INIS)

    Data processing and on-line systems are described for the centralised control of monitoring radiation levels in nuclear industry. The application of these techniques in a study concerning 120 ways of ensuring effective monitoring of a plant preparing radionuclides for CEN-SACLAY is discussed. This included 62 ways of controlling contamination of the air by aerosols, 54 ways of controlling external irradiation and 4 ways of controlling contamination of the air by gases. The improvements in monitoring gained by using such a system and the flexibility of the system are outlined. (U.K.)

  17. Seismic scoping evaluation of high level liquid waste tank vaults at the Idaho Chemical Processing Plant

    International Nuclear Information System (INIS)

    A seismic scoping evaluation of buried vaults enclosing high level liquid waste storage tanks at the Idaho Chemical Processing Plant has been performed. The objective of this evaluation was to scope out which of the vaults could be demonstrated to be seismically adequate against the Safe Shutdown Earthquake (SSE). Using approximate analytical methods, earthquake experience data, and engineering judgement, this study determined that one vault configuration would be expected to meet ICPP seismic design criteria, one would not be considered seismically adequate against the SSE, and one could be shown to be seismically adequate against the SSE using nonlinear analysis

  18. Alternative processes for managing existing commercial high-level radioactive wastes

    International Nuclear Information System (INIS)

    A number of alternatives are discussed for managing high-level radioactive waste presently stored at the West Valley, New York, plant owned by Nuclear Fuel Services, Inc. These alternatives (liquid storage, conversion to cement, shale fracturing, shale cement, calcination, aqueous silicate, conversion to glass, and salt cake) are limited to concepts presently under active investigation by ERDA. Each waste management option is described and examined regarding the status of the technology; its applications to managing NFS waste; its advantages and disadvantages; the research and development needed to implement the option; safety considerations; and estimated costs and time to implement the process

  19. Canada's high-level nuclear waste disposal concept and its evaluation process

    International Nuclear Information System (INIS)

    The concept of disposing high-level nuclear waste in granitic rocks in the Canadian Shield, developed by Atomic Energy of Canada Limited (AECL), is anticipated to undergo a national public review within two years. The disposal concept, its documentation, and its process of evaluation, including the role of the public, government and the scientific/engineering community, are summarized. A Technical Advisory Committee (TAC) has provided external peer review of the Program since 1979 and its findings are published in annual reports which are publicly available. (author)

  20. Molecular processes as basis for plasmid-mediated bacterial UV-light resistance and mutagenesis

    International Nuclear Information System (INIS)

    The increase of UV-resistance and UV-induced mutagenesis by lambda 1 pint intmid as well as molecular-genetic mechanisms of plasmid participation in reparation and DNA replication and its degradation after UV-irradiation in plasmid cells on pKM101 plasmid model have been investigated. Data testifying to the necessity of intmid integration in chromosome as obligatory stage of intmid participation in increasing UV-resistance of bacterial cells are obtained. It has been found that intmid raises UV-resistance of cells and increases respectively the UV-induced reverants efficiency. On the basis of the experiment data the conclusion is drawn that the intmid capacity to raise UV-resistance and, possibly, mutagenesis is bound not only with its integration into chromosome but also with pol A+ chromosome replication by dependendent imtmid replication complex. It is shown that pKM101 plasmid ensures functioning in E coli cells of inducible, chloroamphenicol-resistant DNA replication, highly resistant to UV-light harmful effect and that the volume of excision reparation in E. coli cells carrying pKM101 plasmid is increased as compared with the volume of reparation in plasmid legs cells. The combination of the data obtained gives grounds to the authors to assume that inducible replication, inducible reparation of DNA and inducible decrease of DNA degradation determined by pKM101 plasmid may serve as recA+lexA+ basis dependent increase of UV-resistance and mutagenesis and that these processes provide the possibility of functioning of integrative replication mechanism of plasmid participation in ensuring UV-resistance and mutagenesis of plants

  1. Adaptive neural network controller for the molten steel level control of strip casting processes

    International Nuclear Information System (INIS)

    The twin-roll strip casting process is a steel-strip production method which combines continuous casting and hot rolling processes. The production line from molten liquid steel to the final steel-strip is shortened and the production cost is reduced significantly as compared to conventional continuous casting. The quality of strip casting process depends on many process parameters, such as molten steel level in the pool, solidification position, and roll gap. Their relationships are complex and the strip casting process has the properties of nonlinear uncertainty and time-varying characteristics. It is difficult to establish an accurate process model for designing a model-based controller to monitor the strip quality. In this paper, a model-free adaptive neural network controller is developed to overcome this problem. The proposed control strategy is based on a neural network structure combined with a sliding-mode control scheme. An adaptive rule is employed to on-line adjust the weights of radial basis functions by using the reaching condition of a specified sliding surface. This surface has the on-line learning ability to respond to the system's nonlinear and time-varying behaviors. Since this model-free controller has a simple control structure and small number of control parameters, it is easy to implement. Simulation results, based on a semi experimental system dynamic model and parameters, are executed to show the control performance of the proposed intelligent l performance of the proposed intelligent controller. In addition, the control performance is compared with that of a traditional Pid controller

  2. Forward osmosis - a novel membrane process for concentration of low level radioactive wastes

    International Nuclear Information System (INIS)

    Forward osmosis (FO) is an emerging membrane process in which osmotic pressure differential across a semi-permeable membrane between the solution to be concentrated (feed) and a concentrated solution of high osmotic pressure (draw solution) than the feed is used to effect separation of water from dissolved solutes. With time, feed stream gets concentrated with dilution of draw solution and this technology recently being used as more energy efficient alternative to reverse osmosis (RO) in some of the application areas, particularly for the concentration of low volume high value products. The use of pressure driven membrane processes like reverse osmosis (RO) and ultrafiltration (UF) are already demonstrated in the treatment of radioactive laundry, laboratory effluents and some other applications in nuclear industry. The application of FO membrane process to concentrate simulated inactive ammonium-diuranate (ADU) filtered effluent solution (by mixing uranyl nitrate and ammonium nitrate) using indigenously developed cellulose acetate (CA) and thin-film composite polyamide (TFCP) membranes has been published recently from our laboratory. In this presentation, we briefly discuss our views on possibility of using FO membrane process with proper selection of membrane for concentration of low level radioactive wastes generated in various steps of nuclear fuel cycle in most effective way. (author)

  3. Level set simulations of the anisotropic wet etching process for device fabrication in nanotechnologies

    Directory of Open Access Journals (Sweden)

    Ra?enovi? Branislav

    2010-01-01

    Full Text Available Chemical etching is employed as micromachining manufacturing process to produce micron-size components. As a semiconductor wafer is extremely expensive due to many processing steps involved in the making thereof, the need to critically control the etching end point in an etching process is highly desirable. It was found that not only the etchant and temperature determine the exact anisotropy of etched silicon. The angle between the silicon surface and the mask was also shown to play an important role. In this paper, angular dependence of the etching rate is calculated on the base of the silicon symmetry properties, by means of the interpolation technique using experimentally obtained values of the principal <100>, <110>, <111> directions in KOH solutions. The calculations are performed using an extension of the sparse field method for solving three dimensional (3D level set equations that describe the morphological surface evolution during etching process. The analysis of the obtained results confirm that regardless of the initial shape the profile evolution ends with the crystal form composed of the fastest etching planes, {110} in our model.

  4. Review process for low-level radioactive waste disposal license application under Low-Level Radioactive Waste Policy Amendments Act

    International Nuclear Information System (INIS)

    This document estimates the level of effort and expertise that is needed to review a license application within the required time. It is intended to be used by the NRC staff as well as States and interested parties to provide a better understanding of what the NRC envisions will be involved in licensing a low-level radioactive waste disposal facility. 5 refs., 3 figs., 1 tab

  5. Molecular beam studies of free-radical processes: photodissociation, inelastic and reactive collisions

    International Nuclear Information System (INIS)

    In this review, the production and detection of a wide range of unstable free-radical species under molecular beam conditions are described. The use of such molecular beam methods to study the photodissociation and inelastic and reactive scattering of free radicals in recent years is reviewed. A selection of the many experiments on the photodissociation of radicals that have been performed recently using molecular beam conditions is described to illustrate the range and scope of such experiments. For the comparatively smaller fields of free-radical inelastic and reactive scattering studied using molecular beam techniques, a comprehensive review is presented. In all cases, the experimental results are interpreted and discussed with reference to recent related theoretical calculations on the electronic structure and dynamics for the systems. A particular aim is to illustrate how the observed features of the experiments are related to information on the topography of and the couplings between the appropriate potential energy surfaces and the associated dynamics. (author)

  6. Monitoring of BCR-ABL levels in chronic myeloid leukemia patients treated with imatinib in the chronic phase: the importance of a major molecular response

    Scientific Electronic Library Online (English)

    Melissa Pereira, Machado; Juarez Pires, Tomaz; Irene, Lorand-Metze; Cármino Antonio de, Souza; Afonso Celso, Vigorito; Marcia Torresan, Delamain; Israel, Bendit; Noemi Farah, Pereira; Katia Borgia Barbosa, Pagnano.

    2011-06-01

    Full Text Available BACKGROUND: Real time PCR has become the most common technique to monitor BCR-ABL transcript levels of patients treated with kinase inhibitors. The aim of this study was to evaluate BCR-ABL levels of chronic myeloid leukemia patients treated with imatinib in the chronic phase and correlate the respo [...] nse to therapy and event-free survival. METHODS: BCR-ABL levels were measured in peripheral blood cell samples using Real time PCR at diagnosis and then every 3 months after starting therapy with imatinib. Major molecular response was defined as a three-log reduction from the standardized baseline value. Major molecular response values were adjusted to international scale using a conversion factor of 1.19. The results are reported as a BCR-ABL/ABL ratio (%). RESULTS: Hematological, major cytogenetic and complete cytogenetic responses were achieved by 57 (95%), 45 (75%) and 38 (63%) patients, respectively. Twenty-four out of sixty patients achieved a major molecular response (40%) in a median time of 8.5 months. Overall survival and event free survival were higher for patients with (100%) versus patients without (77%) a complete cytogenetic response (p-value = 0.01) at 48 months. Patients with complete cytogenetic response and major molecular response had a higher event free survival compared to patients with complete cytogenetic response but without major molecular response (p-value = 0.007). CONCLUSION: In conclusion, the prognostic impact of achieving complete cytogenetic response and a major molecular response and also the importance of molecular monitoring in the follow-up of chronic myeloid leukemia patients were demonstrated.

  7. Regulation of molecular processes in diffuse large b-cell lymphoma

    OpenAIRE

    Högfeldt, Therese

    2013-01-01

    The molecular understanding of diseases has advanced rapidly due to the use of gene expression profiling. However, these methods have been hampered by the limitation to use frozen tissue specimens. Formalin fixation and paraffin embedding (FFPE) is a standard procedure for long time storage of tissues. FFPE tissues are available in large numbers and are of value for molecular research with the main challenge of low RNA quality compared to fresh frozen (FF) tissues. This thesis showed importan...

  8. Teaching the Process of Molecular Phylogeny and Systematics: A Multi-Part Inquiry-Based Exercise

    OpenAIRE

    Lents, Nathan H.; Cifuentes, Oscar E.; Carpi, Anthony

    2010-01-01

    Three approaches to molecular phylogenetics are demonstrated to biology students as they explore molecular data from Homo sapiens and four related primates. By analyzing DNA sequences, protein sequences, and chromosomal maps, students are repeatedly challenged to develop hypotheses regarding the ancestry of the five species. Although these exercises were designed to supplement and enhance classroom instruction on phylogeny, cladistics, and systematics in the context of a postsecondary majors-...

  9. Hybrid approach to molecular continuum processes combining Gaussian basis functions and the discrete variable representation

    International Nuclear Information System (INIS)

    Gaussian basis functions, routinely employed in molecular electronic structure calculations, can be combined with numerical grid-based functions in a discrete variable representation to provide an efficient method for computing molecular continuum wave functions. This approach, combined with exterior complex scaling, obviates the need for slowly convergent single-center expansions, and allows one to study a variety of electron-molecule collision problems. The method is illustrated by computation of various bound and continuum properties of H2+

  10. Engineering the Crystalline Morphology of Polymer Thin Films at a Molecular Level via Matrix Assisted Pulsed Laser Evaporation

    Science.gov (United States)

    Jeong, Hyuncheol; Arnold, Craig; Priestley, Rodney

    2015-03-01

    Controlling the crystalline morphology of polymeric thin films at a molecular level has been increasingly important due to their potential as the active layer in organic electronics. Typically, the crystalline morphology in films is achieved via thermal annealing or melt-crystallization of spin-cast polymers. This approach often leads to a spherulitic morphology where the crystalline lamellae grow in all directions. Here, we introduce an alternative approach to make crystalline polymer films via Matrix Assisted Pulsed Laser Evaporation (MAPLE). Using polyethylene oxide (PEO) as a model polymer, we show that the preferential orientation of polymer crystals can be controlled during the film growth. By laser-ablating a frozen dilute solution of the desired polymer, MAPLE provides a non-destructive means for the deposition of polymer films. Due to the liquid nature of as-deposited polymers confined in nanodroplets, this technique can exploit the substrate effect on the crystal nucleation and growth of nano-confined polymers during the film growth. Mimicking the epitaxial growth of metallic films, this novel polymer deposition technique may enable the engineering of film properties in a way not achievable in bulk.

  11. Assessment of Changes in Community Level Physiological Profile and Molecular Diversity of Bacterial Communities in Different Stages of Jute Retting

    Directory of Open Access Journals (Sweden)

    Manabendra Nath Saha

    2013-01-01

    Full Text Available Retting of jute is essentially microbiological and biochemical in nature. Community Level Physiological Profiles (CLPP as well as genomic diversity of bacterial communities were assessed in water samples collected during pre-retting, after 1st and 2nd charges of retting. The water samples were collected from two widely cultivated jute growing locations, Sonatikari (22°41'27"N; 88°35'44"E and Baduria (22°44'24"N; 88°47'24"E, West Bengal, India. The CLPP, expressed as net area under substrate utilization curve, was studied by carbon source utilization patterns in BIOLOG Ecoplates. Molecular diversity was studied by polymerase chain reaction followed by denaturing gradient gel electrophoresis (PCR-DGGE of total DNA from water samples. Both between locations and stages of retting, substrate utilizations pattern were carbohydrates> carboxylic acids>polymers>amino acids>amines/amides>phenolic compounds. Differential substrate utilization pattern as well as variation in banding pattern in DGGE profiles was observed between the two locations and at different stages of retting. The variations in CLPP in different stages of retting were due to the change in bacterial communities.

  12. Kinase Expression and Chromosomal Rearrangements in Papillary Thyroid Cancer Tissues: Investigations at the Molecular and Microscopic Levels

    International Nuclear Information System (INIS)

    Structural chromosome aberrations are known hallmarks of many solid tumors. In the papillary form of thyroid cancer (PTC), for example, activation of the receptor tyrosine kinase (RTK) genes, ret or the neurotrophic tyrosine kinase receptor type I (NTRK1) by intra- or interchromosomal rearrangements have been suggested as a cause of the disease. The 1986 accident at the nuclear power plant in Chernobyl, USSR, led to the uncontrolled release of high levels of radioisotopes. Ten years later, the incidence of childhood papillary thyroid cancer (chPTC) near Chernobyl had risen by two orders of magnitude. Tumors removed from some of these patients showed aberrant expression of the ret RTK gene due to a ret/PTC1 or ret/PTC3 rearrangement involving chromosome 10. However, many cultured chPTC cells show a normal G-banded karyotype and no ret rearrangement. We hypothesize that the 'ret-negative' tumors inappropriately express a different oncogene or have lost function of a tumor suppressor as a result of chromosomal rearrangements, and decided to apply molecular and cytogenetic methods to search for potentially oncogenic chromosomal rearrangements in Chernobyl chPTC cases. Knowledge of the kind of genetic alterations may facilitate the early detection and staging of chPTC as well as provide guidance for therapeutic intervention.

  13. Kinase Expression and Chromosomal Rearrangements in Papillary Thyroid Cancer Tissues: Investigations at the Molecular and Microscopic Levels

    Energy Technology Data Exchange (ETDEWEB)

    Weier, Heinz-Ulrich; Kwan, Johnson; Lu, Chun-Mei; Ito, Yuko; Wang, Mei; Baumgartner, Adolf; Hayward, Simon W.; Weier, Jingly F.; Zitzelsberger, Horst F.

    2009-07-07

    Structural chromosome aberrations are known hallmarks of many solid tumors. In the papillary form of thyroid cancer (PTC), for example, activation of the receptor tyrosine kinase (RTK) genes, ret or the neurotrophic tyrosine kinase receptor type I (NTRK1) by intra- or interchromosomal rearrangements have been suggested as a cause of the disease. The 1986 accident at the nuclear power plant in Chernobyl, USSR, led to the uncontrolled release of high levels of radioisotopes. Ten years later, the incidence of childhood papillary thyroid cancer (chPTC) near Chernobyl had risen by two orders of magnitude. Tumors removed from some of these patients showed aberrant expression of the ret RTK gene due to a ret/PTC1 or ret/PTC3 rearrangement involving chromosome 10. However, many cultured chPTC cells show a normal G-banded karyotype and no ret rearrangement. We hypothesize that the 'ret-negative' tumors inappropriately express a different oncogene or have lost function of a tumor suppressor as a result of chromosomal rearrangements, and decided to apply molecular and cytogenetic methods to search for potentially oncogenic chromosomal rearrangements in Chernobyl chPTC cases. Knowledge of the kind of genetic alterations may facilitate the early detection and staging of chPTC as well as provide guidance for therapeutic intervention.

  14. Surface damage correction, and atomic level smoothing of optics by Accelerated Neutral Atom Beam (ANAB) Processing

    Science.gov (United States)

    Walsh, M.; Chau, K.; Kirkpatrick, S.; Svrluga, R.

    2014-10-01

    Surface damage and surface contamination of optics has long been a source of problems for laser, lithography and other industries. Nano-sized surface defects may present significant performance issues in optical materials for deep UV and EUV applications. The effects of nanometer sized surface damage (scratches, pits, and organics) on the surface of optics made of traditional materials and new more exotic materials is a limiting factor to high end performance. Angstrom level smoothing of materials such as calcium fluoride, spinel, zinc sulfide, BK7 and others presents a unique set of challenges. Exogenesis Corporation, using its proprietary Accelerated Neutral Atom Beam (ANAB) technology, is able to remove nano-scale surface damage and contamination and leaves many material surfaces with roughness typically around one angstrom. This process technology has been demonstrated on nonlinear crystals, and various other high-end optical materials. This paper describes the ANAB technology and summarizes smoothing results for various materials that have been processed with ANAB. All surface measurement data for the paper was produced via AFM analysis. Exogenesis Corporation's ANAB processing technology is a new and unique surface modification technique that has demonstrated to be highly effective at correcting nano-scale surface defects. ANAB is a non-contact vacuum process comprised of an intense beam of accelerated, electrically neutral gas atoms with average energies of a few tens of electron volts. The ANAB process does not apply normal forces associated with traditional polishing techniques. ANAB efficiently removes surface contaminants, nano-scale scratches, bumps and other asperities under low energy physical sputtering conditions as the removal action proceeds. ANAB may be used to remove a precisely controlled, uniform thickness of material without any increase of surface roughness, regardless of the total amount of material removed. The ANAB process does not involve the use of slurries or other polishing compounds and therefore does not require any post process cleaning. ANAB can be integrated as an in-situ surface preparation method for other process steps in the uninterrupted fabrication of optical devices.

  15. ATOMIC AND MOLECULAR PHYSICS: Coherent Phase Control of Multiphoton Ionization in Three-Level Ladder-Type System

    Science.gov (United States)

    Zhang, Shi-An; Chen, Yu-Ting; Wang, Zu-Geng; Sun, Zhen-Rong

    2009-03-01

    We present the theoretical investigation of photoelectron spectroscopy resulting from the strong field induced multiphoton ionization in a typical three-level ladder-style system. Our theoretical results show that the photo-electron spectral structure can be alternatively steered by spectral phase modulation. This physical mechanism for strong field quantum control is explicitly exploited by the time-dependent dressed state population. It is concluded that the phase-shaped laser pulses can be used to selectively manipulate the multiphoton ionization process in complicated quantum systems.

  16. The improvement of the manufacturing process of a company by the Sigma level: the case of the company BAG (Batna

    Directory of Open Access Journals (Sweden)

    Athmane MECHENENE

    2014-06-01

    Full Text Available This modest work aims to evaluate the performance of the manufacturing process of the company by a new measurement tool, namely the sigma level whose purpose is to quantify the costs inherent in each production process, measure the levels of six Sigma in adjacent processes, to achieve weight calculate DPMO (Defects Per Million Opportunity and thus assess the overall competitiveness of the company. This new tool for measuring the performance of the manufacturing process (sigma level is applied to manufacturing gas cylinders (BAG - Batna.

  17. Chemical precipitation processes for the treatment of low- and medium-level liquid waste

    International Nuclear Information System (INIS)

    New applications of chemical precipitation processes for the treatment of various radioactive low and medium level liquid waste have been investigated. For reducing the overall management cost and improving the long-term safety of disposal, partitioning of the reprocessing concentrate into different streams for separate conditioning, packaging and disposal has been studied through chemical precipitation of the whole activity (actinides + main gamma emitters) or the actinides only. Results achieved on testing of real sample of reprocessing concentrate (lab-scale) are presented and discussed. In order to comply with the ALARA principle, an industrial flocculator prototype has been constructed and successfully operated for the treatment of utility liquid waste arising at the Chooz PWR site. Combination of chemical precipitation with ultrafiltration seems quite promising for improving both decontamination and volume reduction factors for the treatment of various radwastes. On the basis of experimental tests performed successively on lab and technical scales, a pilot plant has been designed, constructed and commissioned for the treatment of Harwell low and medium level liquid wastes. First active runs confirm the merits of the process

  18. In what extent classic radiation biology can be understand at the molecular level? Biological effects of ionizing radiation and repair mechanism of double strand breaks of DNA

    Energy Technology Data Exchange (ETDEWEB)

    Utsumi, Hiroshi [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.

    2000-09-01

    This review revealed that classic radiation biology phenomena not based on substantial concept, such as lethal damage, sublethal damage, potentially lethal damage, recoveries from them, variation of radiation sensitivity due to cell cycle, RBE/LET relationships and mathematical expression of survival curve, can be described only at the levels of DNA double strand breaks (DSB) and its repair mechanism. Authors investigated chicken cells with DSB repair-defect, analyzed the molecular mechanisms of 'Elkind recovery' where cell survival rates are higher after fractionated irradiation than after single irradiation at a fixed dose, and showed that the phenomenon was derived from the cell revival resulting from homologous recombination repair of DSB yielded on homologous chromosome DNA. Investigations using HIMAC also revealed the molecular mechanisms of RBE/LET in those cells. Findings indicate that biological effects of ionizing radiation can be described at the molecular level.(K.H.)

  19. Ground-level ozone in four Chinese cities: precursors, regional transport and heterogeneous processes

    Directory of Open Access Journals (Sweden)

    L. K. Xue

    2014-08-01

    Full Text Available We analyzed measurements of ozone (O3 and its precursors made at rural/suburban sites downwind of four large Chinese cities – Beijing, Shanghai, Guangzhou and Lanzhou, to elucidate their pollution characteristics, regional transport, in situ production, and impacts of heterogeneous processes. The same measurement techniques and observation-based model were used to minimize uncertainties in comparison of the results due to difference in methodologies. All four cities suffered from serious O3 pollution but showed different precursor distributions. The model-calculated in situ O3 production rates were compared with the observed change rates to infer the relative contributions of on-site photochemistry and transport. At the rural site of Beijing, export of the well-processed urban plumes contributed to the extremely high O3 levels (up to an hourly value of 286 ppbv, while the O3 pollution observed at suburban sites of Shanghai, Guangzhou and Lanzhou was dominated by intense in-situ production. The O3 production was in a VOCs-limited regime in both Shanghai and Guangzhou, and a NOx-controlled regime in Lanzhou. The key VOC precursors are aromatics and alkenes in Shanghai, and aromatics in Guangzhou. The potential impacts on O3 production of several heterogeneous processes, namely, hydrolysis of dinitrogen pentoxide (N2O5, uptake of hydro peroxy radical (HO2 on particles and surface reactions of NO2 forming nitrous acid (HONO, were assessed. The analyses indicate the varying and considerable impacts of these processes in different areas of China depending on the atmospheric abundances of aerosol and NOx, and suggest the urgent need to better understand these processes and represent them in photochemical models.

  20. Ground-level ozone in four Chinese cities: precursors, regional transport and heterogeneous processes

    Science.gov (United States)

    Xue, L. K.; Wang, T.; Gao, J.; Ding, A. J.; Zhou, X. H.; Blake, D. R.; Wang, X. F.; Saunders, S. M.; Fan, S. J.; Zuo, H. C.; Zhang, Q. Z.; Wang, W. X.

    2014-12-01

    We analyzed the measurements of ozone (O3) and its precursors made at rural/suburban sites downwind of four large Chinese cities - Beijing, Shanghai, Guangzhou and Lanzhou, to elucidate their pollution characteristics, regional transport, in situ production, and impacts of heterogeneous processes. The same measurement techniques and observation-based model were used to minimize uncertainties in comparison of the results due to difference in methodologies. All four cities suffered from serious O3 pollution but showed different precursor distributions. The model-calculated in situ O3 production rates were compared with the observed change rates to infer the relative contributions of on-site photochemistry and transport. At the rural site downwind of Beijing, export of the well-processed urban plumes contributed to the extremely high O3 levels (up to an hourly value of 286 ppbv), while the O3 pollution observed at suburban sites of Shanghai, Guangzhou and Lanzhou was dominated by intense in situ production. The O3 production was in a volatile organic compound (VOC)-limited regime in both Shanghai and Guangzhou, and a NOx-limited regime in Lanzhou. The key VOC precursors are aromatics and alkenes in Shanghai, and aromatics in Guangzhou. The potential impacts on O3 production of several heterogeneous processes, namely, hydrolysis of dinitrogen pentoxide (N2O5), uptake of hydro peroxy radical (HO2) on particles and surface reactions of NO2 forming nitrous acid (HONO), were assessed. The analyses indicate the varying and considerable impacts of these processes in different areas of China depending on the atmospheric abundances of aerosol and NOx, and suggest the urgent need to better understand these processes and represent them in photochemical models.