WorldWideScience

Sample records for molecular level processes

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

    Directory of Open Access Journals (Sweden)

    Ilko Bald

    2014-09-01

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

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

    International Nuclear Information System (INIS)

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

  3. 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 Kashas 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 spinorbit 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 spinorbit 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Shuai, Zhigang, E-mail: zgshuai@tsinghua.edu.cn [MOE Key Laboratory of Organic OptoElectronics and Molecular Engineering, Department of Chemistry, Tsinghua University, 100084 Beijing (China); Peng, Qian, E-mail: qpeng@iccas.ac.cn [Beijing National Laboratory for Molecular Science (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, 100190 Beijing (China)

    2014-04-01

    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 Kashas 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 2A{sub g} 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 1B{sub u}/2A{sub g} 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 spinorbit 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 spinorbit 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. Mathematical model and calculation algorithm of micro and meso levels of separation process of gaseous mixtures in molecular sieves

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Umarova, Zhanat; Botayeva, Saule; Yegenova, Aliya; Usenova, Aisaule [South Kazakhstan State University, 5, Tauke Khan Avenue, 160012 Shymkent (Kazakhstan)

    2015-05-15

    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.

  7. 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.

  8. Probing ice-nucleation processes on the molecular level using second harmonic generation spectroscopy

    Science.gov (United States)

    Abdelmonem, A.; Ltzenkirchen, J.; Leisner, T.

    2015-08-01

    We present and characterize a novel setup to apply second harmonic generation (SHG) spectroscopy in total internal reflection geometry (TIR) to heterogeneous freezing research. It allows to monitor the evolution of water structuring at solid surfaces at low temperatures prior to heterogeneous ice nucleation. Apart from the possibility of investigating temperature dependence, a major novelty in our setup is the ability of measuring sheet-like samples in TIR geometry in a direct way. As a main experimental result, we find that our method can discriminate between good and poor ice nucleating surfaces. While at the sapphire basal plane, which is known to be a poor ice nucleator, no structural rearrangement of the water molecules is found prior to freezing, the basal plane surface of mica, an analogue to ice active mineral dust surfaces, exhibits a strong change in the nonlinear optical properties at temperatures well above the freezing transition. This is interpreted as a pre-activation, i.e. an increase in the local ordering of the interfacial water which is expected to facilitate the crystallization of ice at the surface. The results are in line with recent predictions by molecular dynamics simulations on a similar system.

  9. Probing ice-nucleation processes on the molecular level using second harmonic generation spectroscopy

    Directory of Open Access Journals (Sweden)

    A. Abdelmonem

    2015-05-01

    Full Text Available We present and characterize a novel setup to apply Second Harmonic Generation (SHG spectroscopy in total internal reflection geometry (TIR to heterogeneous freezing research. It allows to monitor the evolution of water structuring at solid surfaces at low temperatures prior to heterogeneous ice nucleation. Apart from the possibility of investigating temperature dependence, a major novelty in our setup is the ability of measuring sheet-like samples in TIR geometry in a direct way. As a main experimental result, we find that our method can discriminate between good and poor ice nucleating surfaces. While at the sapphire basal plane, which is known to be a poor ice nucleator, no structural rearrangement of the water molecules is found prior to freezing, the basal plane surface of mica, an analogue to ice active mineral dust surfaces, exhibits a strong change in the nonlinear optical properties at temperatures well above the freezing transition. This is interpreted as a pre-activation, i.e. an increase in the local ordering of the interfacial water which is expected to facilitate the crystallization of ice at the surface. The results are in line with recent predictions by Molecular Dynamics simulations on a similar system.

  10. At Molecular level

    International Nuclear Information System (INIS)

    Cancer involves abnormal growth and growth depends on energy metabolism. The response of ATP levels and isocitrate dehydrogenase activity in CaNT tumours, after different sorts of ionising radiation, was investigated in order to shed some light on the complex relationships between energy metabolism, radiation damage and repair processes and their implication for cancer therapy. Male mice were inoculated with tumour cells and the subsequent tumours were irradiated with different photon energies. The levels of ATP in the CaNT tumours were measured 2.5 hours after receiving 10 Gy of the different photon energies: 100 kVp X-rays, 250 kVp X-rays, 60Co gamma-rays and 8 MeV X-rays. The resulting measured ATP concentrations with respect to unirradiated controls were 3.78 times with 100 kVp, 1.56 times greater with 250 kVp and 1.23 times greater with 1.17/1.33 MeV gammas. With 8 MeV radiation, the tumour ATP concentration remained unchanged to within the experimental uncertainty. ATP appeared to play an important role in repair mechanisms, including cellular repair following radiation damage. The increased reducing equivalents generated by this enzyme under injury conditions give protection against further damage due to peroxidative processes in membrane repair. Thus, the initial increase in energy metabolism after the dose of ionising radiation represents an adaptive defence mechanism against radiation damage. 14 refs., 3 figs., 2 tabs

  11. 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; Wichterlov, Blanka; D?de?ek, Ji?; Tvar?kov, Zdenka; Sathu, Naveen Kumar; Kreibich, Viktor; Sobalk, Zden?k

    Prague : J. Heyrovsk Institute of Physical Chemistry of the ASCR, v.v.i, 2011 - (Hor?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

  12. 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

  13. Discrete Atomic Layers at the Molecular Level

    Science.gov (United States)

    Yorimitsu, Hideki; Bhanuchandra, M.

    2015-12-01

    In this review, we deal with the syntheses of large discrete atomic layers at the molecular level. Spectroscopic measurements as well as X-ray crystallographic analyses lead to unambiguous characterizations of these layers. The molecular atomic layers can be considered to be parts of graphenes and related atomic layers, thereby helping to understand such indefinitely huge atomic layers or serving as seeds for the controlled synthesis of nanocarbons.

  14. Occupation number dependence of molecular energy levels

    International Nuclear Information System (INIS)

    The Roothaan expression for the energy of a closed-shell molecular system is generalized in order to apply to open shells. A continuous variation from 0 to 2 is supposed for each level's occupation number, extending to this range tbe correction due to the spurious repulsion appearing in the half-electron method. The characteristic equations of the X? method are applied to the energy expressions. The one level case is discussed in detail. Ionic and excited states of the 1,3 transbutadiene ? system are analyzed

  15. Atomic and molecular processes in fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-01-01

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

  16. Understanding diseases at a molecular level

    Energy Technology Data Exchange (ETDEWEB)

    Rosev, Tatjana K [Los Alamos National Laboratory

    2008-01-01

    A group of scientists at Los Alamos National Laboratory in 2008 successfully pioneered a microscope able to track protein-sized, hard to see particles in three dimensions. The 3D Tracking Microscope, designed and developed by James H. Werner, Guillaume A. Lessard, Nathan Wells and Peter M. Goodwin of LANL's Center for Integrated Nanotechnologies, won a 2008 R&D 100 award. The team's invention is a unique confocal 3D tracking microscope capable of following the motion of nanometer-sized objects, such as individual molecules, quantum dots, organic fluorophores and single green fluorescent proteins as they zoom through three-dimensional space at rates faster than many intracellular transport processes. The 3D tracking microscope can follow the transport of nanometer-sized particles at micrometer per second rates. This enables researchers to follow individual protein, ribonucleic acid (RNA), or deoxyribonucleic acid (DNA) motion throughout the full three-dimensional volume of a cell to discover the path a particular biomolecule takes, the method it employs to get there and the specific proteins it may be interacting with along the way. In addition to applications in molecular spectroscopy and materials research, the 3D tracking microscope is a powerful tool primarily in the fields of cellular biology and biomedical research, Werner said. 'The 3D tracking microscope will advance our understanding of the molecular basis and kinetics of many diseases, such as cancer, diabetes, or muscular dystrophy,' he said. 'We anticipate the microscope will become a valuable weapon in the arsenal of biomedical researchers who are fighting to find cures for cancer, heart disease and other protein or DNA-based diseases.'

  17. 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 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 applications. (author)

  18. Molecular-level dynamics of refractory dissolved organic matter

    Science.gov (United States)

    Niggemann, J.; Gerdts, G.; Dittmar, T.

    2012-04-01

    Refractory dissolved organic matter (DOM) accounts for most of the global oceanic organic carbon inventory. Processes leading to its formation and factors determining its stability are still largely unknown. We hypothesize that refractory DOM carries a universal molecular signature. Characterizing spatial and temporal variability in this universal signature is a key to understanding dynamics of refractory DOM. We present results from a long-term study of the DOM geo-metabolome in the open North Sea. Geo-metabolomics considers the entity of DOM as a population of compounds, each characterized by a specific function and reactivity in the cycling of energy and elements. Ten-thousands of molecular formulae were identified in DOM by ultrahigh resolution mass spectrometry analysis (FT-ICR-MS, Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry). The DOM pool in the North Sea was influenced by a complex interplay of processes that produced, transformed and degraded dissolved molecules. We identified a stable fraction in North Sea DOM with a molecular composition similar to deep ocean DOM. Molecular-level changes in this stable fraction provide novel information on dynamics and interactions of refractory DOM.

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. Bibliography of atomic and molecular processes, 1983

    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.)

    1984-10-01

    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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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

    Energy Technology Data Exchange (ETDEWEB)

    Bulienkov, N. A., E-mail: lmm@phyche.ac.ru [Russian Academy of Sciences, Frumkin Institute of Physical Chemistry and Electrochemistry (Russian Federation)

    2011-07-15

    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.

  11. Molecular sieving silica membrane fabrication process

    Science.gov (United States)

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

    1999-08-10

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

  12. Quantum mechanics of molecular rate processes

    CERN Document Server

    Levine, Raphael D

    1999-01-01

    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.

  13. Mass separation during molecular beam sampling process

    International Nuclear Information System (INIS)

    In a molecular beam sampling process, if the stagnation gas is a mixture, heavier species are concentrated onto the axis of the molecular beam, while lighter ones are diffused away from it. This phenomenon is generally called ''mass separation.'' Mass separation is caused mainly by three phenomena: (1) pressure diffusion, (2) Mach-number focusing and (3) skimmer interference. Pressure diffusion has already been analyzed by Sherman. In the present work, the mass separation for a binary mixture of Ar and He was experimentally measured by means of a molecular beam-mass filter system, and its kinetic analysis was carried out with regard to Mach-number focusing taking into consideration of the non-equilibrium of translational temperatures. The experimental results and the theoretical prediction agree well except in the cases of a shorter nozzle-skimmer distance, where skimmer interference is dominant, and in the cases of a higher Ar content. (author)

  14. Levels of Processing in Mild Disabilities.

    Science.gov (United States)

    Al-Hilawani, Yasser A.; And Others

    This study examined the effects of the second level (intermediate acoustical processing of rhyming words) and the third level (deep-semantic processing of words in sentences) of the "levels of processing" framework on memory performance of four types of intermediate-grade students (52 "normal" students, 50 students with learning disabilities, 25

  15. Higher-level motor processes.

    Science.gov (United States)

    Rumiati, Raffaella Ida; Papeo, Liuba; Corradi-Dell'Acqua, Corrado

    2010-03-01

    Traditionally the motor system was thought of as a movement output device that, after brain damage, can impede patients from correctly planning and executing an action. In the last 20 years neuropsychological observations have contributed to the development of a new view that attributes higher-level functions to this system. Rapidly, this area of investigation has grown very popular, with motor representations being considered critical for action and object recognition, imagery and even language understanding. At present, we can distinguish between embodied and disembodied theories. The former predominantly are built on associations of deficits in these abilities whereas the latter rely on dissociations between deficits. Neuroimaging research has also showed that different action-related functions activate either overlapping or discrete regions, thus sustaining either association-based or dissociation-based models. Although no convincing theory is, to date, available to explain both sets of observations, cognitive neuroscientists have begun to explore this intermediate hypothesis space. Here we suggest that concepts like strategy and simulation seem promising in explaining how the cognitive system alternates between action-related functions. PMID:20392283

  16. Catalysis and kinetics molecular level considerations

    CERN Document Server

    Marin, Guy B

    2013-01-01

    Advances in Chemical Engineering was established in 1960 and is the definitive serial in the area. It is one of great importance to organic chemists, polymer chemists, and many biological scientists. Written by established authorities in the field, the comprehensive reviews combine descriptive chemistry and mechanistic insight and yield an understanding of how the chemistry drives the properties. This volume covers the topic of catalysis and kinetics and aspects in chemical engineering.Control and optimization of process systemsPolyelectrolytesPropane dehydrogenation and selective oxidation of

  17. High levels of molecular chlorine in the Arctic atmosphere

    Science.gov (United States)

    Liao, Jin; Huey, L. Gregory; Liu, Zhen; Tanner, David J.; Cantrell, Chris A.; Orlando, John J.; Flocke, Frank M.; Shepson, Paul B.; Weinheimer, Andrew J.; Hall, Samuel R.; Ullmann, Kirk; Beine, Harry J.; Wang, Yuhang; Ingall, Ellery D.; Stephens, Chelsea R.; Hornbrook, Rebecca S.; Apel, Eric C.; Riemer, Daniel; Fried, Alan; Mauldin, Roy L.; Smith, James N.; Staebler, Ralf M.; Neuman, J. Andrew; Nowak, John B.

    2014-02-01

    Chlorine radicals can function as a strong atmospheric oxidant, particularly in polar regions, where levels of hydroxyl radicals are low. In the atmosphere, chlorine radicals expedite the degradation of methane and tropospheric ozone, and the oxidation of mercury to more toxic forms. Here we present direct measurements of molecular chlorine levels in the Arctic marine boundary layer in Barrow, Alaska, collected in the spring of 2009 over a six-week period using chemical ionization mass spectrometry. We report high levels of molecular chlorine, of up to 400 pptv. Concentrations peaked in the early morning and late afternoon, and fell to near-zero levels at night. Average daytime molecular chlorine levels were correlated with ozone concentrations, suggesting that sunlight and ozone are required for molecular chlorine formation. Using a time-dependent box model, we estimate that the chlorine radicals produced from the photolysis of molecular chlorine oxidized more methane than hydroxyl radicals, on average, and enhanced the abundance of short-lived peroxy radicals. Elevated hydroperoxyl radical levels, in turn, promoted the formation of hypobromous acid, which catalyses mercury oxidation and the breakdown of tropospheric ozone. We therefore suggest that molecular chlorine exerts a significant effect on the atmospheric chemistry of the Arctic.

  18. High Levels of Molecular Chlorine found in the Arctic Atmosphere

    Science.gov (United States)

    Liao, J.; Huey, L. G.; Liu, Z.; Tanner, D.; Cantrell, C. A.; Orlando, J. J.; Flocke, F. M.; Shepson, P. B.; Weinheimer, A. J.; Hall, S. R.; Beine, H.; Wang, Y.; Ingall, E. D.; Thompson, C. R.; Hornbrook, R. S.; Apel, E. C.; Fried, A.; Mauldin, L.; Smith, J. N.; Staebler, R. M.; Neuman, J. A.; Nowak, J. B.

    2014-12-01

    Chlorine radicals are a strong atmospheric oxidant, particularly in polar regions where levels of hydroxyl radicals can be quite low. In the atmosphere, chlorine radicals expedite the degradation of methane and tropospheric ozone and the oxidation of mercury to more toxic forms. Here, we present direct measurements of molecular chlorine levels in the Arctic marine boundary layer in Barrow, Alaska, collected in the spring of 2009 over a six-week period using chemical ionization mass spectrometry. We detected high levels of molecular chlorine of up to 400 pptv. Concentrations peaked in the early morning and late afternoon and fell to near-zero levels at night. Average daytime molecular chlorine levels were correlated with ozone concentrations, suggesting that sunlight and ozone are required for molecular chlorine formation. Using a time-dependent box model, we estimated that the chlorine radicals produced from the photolysis of molecular chlorine on average oxidized more methane than hydroxyl radicals and enhanced the abundance of short-lived peroxy radicals. Elevated hydroperoxyl radical levels, in turn, promoted the formation of hypobromous acid, which catalyzed mercury oxidation and the breakdown of tropospheric ozone. Therefore, we propose that molecular chlorine exerts a significant effect on the atmospheric chemistry in the Arctic. While the formation mechanisms of molecular chlorine are not yet understood, the main potential sources of chlorine include snowpack, sea salt, and sea ice. There is recent evidence of molecular halogen (Br2 and Cl2) formation in the Arctic snowpack. The coverage and composition of the snow may control halogen chemistry in the Arctic. Changes of sea ice and snow cover in the changing climate may affect air-snow-ice interaction and have a significant impact on the levels of radicals, ozone, mercury and methane in the Arctic troposphere.

  19. From supramolecular electrochemistry to molecular-level devices

    International Nuclear Information System (INIS)

    Supramolecular (multi-component) systems can perform complex functions which result from the cooperation of actions performed by suitably selected molecular components. Looking at supramolecular systems, from the viewpoint of the functions, shows that the concept of macroscopic device can be extended to molecular level. Nature exploits very complex molecular-level devices to substain life, and, in the last twenty years, the development of supramolecular chemistry has allowed the construction of simple molecular-level devices, that are of interest not only for basic research, but also for the growth of nanoscience and nanotechnology. Molecular-level devices operate via electronic and/or nuclear rearrangements, and like macroscopic devices, they need energy to operate and signals to communicate with the operator. Electrochemistry can provide the answer to this dual requirement, since electrons/holes, besides supplying the energy needed to make a devices work, can also be useful to 'read' the state of the system and thus to control and monitor the operation of the device. In this article, some examples of molecular-level devices investigated in our laboratory will be reviewed

  20. Levels of Noise Processing and Attentional Control

    Science.gov (United States)

    Keren, Gideon; And Others

    1977-01-01

    Research by Posner and Mitchell (1967) was used to investigate levels of noise processing in testing subjects' ability to "gate out" the processing of irrelevant and unwanted material. Three experiments are reported in which subjects had to judge whether two letters were the "same" or "different". Noise elements were included to test attention

  1. Process for the production of a molecular sieve material:

    OpenAIRE

    Melian, C.I.; Kapteijn, F (Freek); Moulijn, J. A.

    2006-01-01

    The invention concerns a process for the production of a molecular sieve material by growing the molecular sieve material structure in the presence of a template for the pore structure, followed by removal of the template from the molecular sieve material, in which process the template is removed by oxidation of the template material using an oxidising agent.

  2. 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)

  3. 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).

  4. A System-level, molecular evolutionary analysis of mammalian phototransduction

    OpenAIRE

    Invergo, Brandon M.

    2013-01-01

    Phototransduction is the biochemical process by which a light stimulus is converted to a neuronal signal. The process functions through complex interactions between many proteins, which work in concert to tightly control the dynamics of the photoresponse. The primary aim of this thesis is to describe how the topology and kinetics of these interactions have given rise to detectable patterns of molecular evolution. To this end, a secondary aim is to develop a comprehensive ...

  5. User-Level Process Migration Mechanism

    Directory of Open Access Journals (Sweden)

    Dr. Narayan A. Joshi

    2013-02-01

    Full Text Available In networks of workstations, running processes lead to a situation, in which some of the nodes are highly loaded whereas other nodes mayremain lightly loaded or almost idle. It may lead to reduction in throughput and lot of computational power offered by the lightly loaded or the idle processors. This computational power goes unused while the jobs are striving for the availability of processor-cycles. The issue of efficient utilization of computing resources is noteworthy in the networked workstations such as local area networks as well; which can be tackled by spreading the running processes among the connected workstations by means of the mechanism such as process migration. The application of process migrationmechanism may consequent into the proficient utilization of the overall networked computing environment through the utilization of the lightly loaded workstations or the almost idle workstations. The paper discusses characteristics of many user level process migration mechanisms.

  6. 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 obtained. We give...

  7. Nanoparticles of Copper Stimulate Angiogenesis at Systemic and Molecular Level

    Directory of Open Access Journals (Sweden)

    Natalia Mroczek-Sosnowska

    2015-03-01

    Full Text Available Copper is a key element affecting blood vessel growth and muscle development. However, the ions released from Cu salts are toxic. Given their specific physicochemical properties, nanoparticles of Cu (NanoCu may have different bioactivity and affect the development of blood vessel and muscles in a different manner than Cu salts. The objective of the study was to evaluate the influence of NanoCu on embryo development and angiogenesis at the systemic and molecular level, in experiments using a chick embryo model. Fertilized chicken eggs were divided into a control group, and groups injected with a placebo, CuSO4 or NanoCu. Embryo development at the whole body level and molecular indices using an embryo chorioallantoic membrane model were measured during embryogenesis. The present study indicated for the first time that NanoCu have pro-angiogenic properties at the systemic level, to a greater degree than CuSO4 salt. The properties of NanoCu were confirmed at the molecular level, demonstrating significant effects on mRNA concentration and on mRNA gene expression of all pro-angiogenic and pro-proliferative genes measured herein.

  8. 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.

  9. A Process Calculus for Molecular Interaction Maps

    CERN Document Server

    Barbuti, Roberto; Milazzo, Paolo; Pardini, Giovanni; Rama, Aureliano; 10.4204/EPTCS.11.3

    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 obtained. We give a formal definition of the syntax and semantics of the MIM calculus, and we study properties of the formalism. A case study is also presented to show the use of the calculus for modeling biomolecular networks.

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

    DEFF Research Database (Denmark)

    Larade, Brian; Taylor, Jeremy Philip

    2001-01-01

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

  11. Renewal processes and fluctuation analysis of molecular motor stepping

    CERN Document Server

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

    2005-01-01

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

  12. A new vibrational level of the H2+ molecular ion

    International Nuclear Information System (INIS)

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

  13. 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...

  14. Multi-level molecular modelling for plasma medicine

    Science.gov (United States)

    Bogaerts, Annemie; Khosravian, Narjes; Van der Paal, Jonas; Verlackt, Christof C. W.; Yusupov, Maksudbek; Kamaraj, Balu; Neyts, Erik C.

    2016-02-01

    Modelling at the molecular or atomic scale can be very useful for obtaining a better insight in plasma medicine. This paper gives an overview of different atomic/molecular scale modelling approaches that can be used to study the direct interaction of plasma species with biomolecules or the consequences of these interactions for the biomolecules on a somewhat longer time-scale. These approaches include density functional theory (DFT), density functional based tight binding (DFTB), classical reactive and non-reactive molecular dynamics (MD) and united-atom or coarse-grained MD, as well as hybrid quantum mechanics/molecular mechanics (QM/MM) methods. Specific examples will be given for three important types of biomolecules, present in human cells, i.e. proteins, DNA and phospholipids found in the cell membrane. The results show that each of these modelling approaches has its specific strengths and limitations, and is particularly useful for certain applications. A multi-level approach is therefore most suitable for obtaining a global picture of the plasma–biomolecule interactions.

  15. 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

  16. 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...

  17. Molecular processes and turbulent magnetic fields in the solar atmosphere

    Science.gov (United States)

    Shapiro, A. I.

    2008-08-01

    Coherent scattering in the solar atmosphere leads to the formation of the linearly polarized solar spectrum, just like Rayleigh scattering leads to the polarization of the blue sky. One of the most prominent features of the linearly polarized solar spectrum is the CN violet system as it is also in the unpolarized spectrum. This thesis is devoted to the modeling and interpretation of this system in both spectra and developing it into a very sensitive tool for studying the magnetic fields and the temperature structure of the solar atmosphere. The understanding of the solar magnetic field structure is very important as it is connected with and even controls most of the solar activity phenomena. Zeeman effect diagnostics allows to measure strong directed magnetic fields which only cover about 1% of the solar atmosphere. The remaining part is occupied by weak entangled magnetic fields with mixed polarity, which might significantly contribute to the overall solar magnetic energy. These fields are invisible to the Zeeman effect due to signal cancellation. Therefore the discovery of the linearly polarized solar spectrum opened a new epoch in solar physics. The polarization due to the scattering processes is modified by weak entangled magnetic fields via the Hanle effect and thus, provides us with a unique possibility to access and study such "hidden" magnetic fields. Molecular lines are very useful for probing magnetic fields as, due to their strong temperature sensitivity, different molecules sample different, narrow layers of the solar atmosphere. Therefore the extension of the atomic Hanle effect to molecular lines can provide the 3D structure of the solar turbulent magnetic field. Moreover, due to the broad range of magnetic sensitivities within narrow spectral regions molecular lines can be used for employing the differential Hanle effect technique, which allows dramatically reduced model dependence of the obtained magnetic field. This thesis consists of two main parts which reflect the two consecutive steps in the modeling of the polarized solar spectrum. First, the physical properties of the molecular scattering process have to be understood. For the CN violet system, it implies taking into account the Paschen-Back effect on the fine structure (which results in a change of intensities and line positions) and interference effects between the fine structure components itself. Both effects influence the Hanle effect and lead to the consequences which are analyzed in detail in the first part of this thesis. Then, to connect the coherent scattering and physical properties of the solar plasma with the emerged solar radiation, which is measured by our detectors, radiative transfer theory has to be applied. The presence of the scattering processes implies the non-equilibrium nature of the problem. Its self-consistent solution is especially complicated for molecular bands as they usually consist of a huge number of transitions which couple the numerous vibrational-rotational molecular levels. This, for example, makes the two-level approximation, often used in atomic calculations unsuitable. Moreover, there is a strong lack of information about the molecular collision rates so they basically enter the calculations as additional free parameter. In the second part of the thesis we present two radiative transfer models with different degrees of complexity and applicability. These models allow us to successfully fit the observations of the CN violet system in both polarized and unpolarized spectra and provide us with a magnetic field estimation. We discuss in detail the model-dependence of our results and general problems of the 1D solar spectrum modeling. The enormous potential of the linearly polarized solar spectrum makes it one of the main tools for studying solar magnetic fields, which becomes very urgent nowadays, as they can affect the Earth's climate and, hence, our life.

  18. Capillary leveling of stepped films with inhomogeneous molecular mobility

    CERN Document Server

    McGraw, Joshua D; Bumchen, Oliver; Raphal, 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-...

  19. How Effective Are Simulated Molecular-level Experiments for Teaching Diffusion and Osmosis?

    OpenAIRE

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

    2005-01-01

    Diffusion and osmosis are central concepts in biology, both at the cellular and organ levels. They are presented several times throughout most introductory biology textbooks (e.g., Freeman, 2002), yet both processes are often difficult for students to understand (Odom, 1995; Zuckerman, 1994; Sanger et al., 2001; and results herein). Students have deep-rooted misconceptions about how diffusion and osmosis work, especially at the molecular level. We hypothesized that this might be in part due t...

  20. Ab Initio Interactive Molecular Dynamics on Graphical Processing Units (GPUs).

    Science.gov (United States)

    Luehr, Nathan; Jin, Alex G B; Martnez, Todd J

    2015-10-13

    A virtual molecular modeling kit is developed based on GPU-enabled interactive ab initio molecular dynamics (MD). The code uses the TeraChem and VMD programs with a modified IMD interface. Optimization of the GPU accelerated TeraChem program specifically for small molecular systems is discussed, and a robust multiple time step integrator is employed to accurately integrate strong user-supplied pulling forces. Smooth and responsive visualization techniques are developed to allow interactive manipulation at minimum simulation rates below five MD steps per second. Representative calculations at the Hartree-Fock level of theory are demonstrated for molecular systems containing up to a few dozen atoms. PMID:26574246

  1. Process Development Strategies in Plant Molecular Farming.

    Science.gov (United States)

    Buyel, Johannes F

    2015-01-01

    Protein-based biopharmaceuticals are often produced in mammalian cell cultures, which are more expensive than microbial systems but capable of authentic post-translational modifications. The costs are lower if plants are used as an alternative platform to produce complex proteins such as monoclonal antibodies, vaccines and enzymes. This review highlights recent advances that have been achieved in plant-based biopharmaceutical production platforms in terms of expression strategies, product yields and process development. The first generation of plant-derived pharmaceuticals now entering the market is also discussed. Finally, the review considers the downstream processing of plant-derived pharmaceuticals which can account for up to 80% of the production costs. In this context, recent improvements in clarification and integrated process methods will have a strong impact on the economic feasibility of production, especially if supported by and combined with process analytical technology as part of the quality-by-design initiative. PMID:26343135

  2. Directionality and processivity of molecular motors.

    Science.gov (United States)

    Higuchi, Hideo; Endow, Sharyn A

    2002-02-01

    Analysis of a mutant with altered directionality has led to new insights into motor directionality. The prediction from current models for processivity of a two-heads-bound state has been confirmed by electron microscopy for myosin V and by unbinding experiments for kinesin. Evidence is emerging that non-processive motors bind their filament with one head, hydrolyze ATP and then release, requiring binding by a second motor to complete a step. PMID:11792544

  3. 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.

  4. 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.

  5. A Property Based Approach for Simultaneous Process and Molecular Design

    OpenAIRE

    Eljack, F.T.; Solvason, Charles Conrad; Chemmangattuvalappil, Nishanth; Eden, Mario R.

    2009-01-01

    In this work, property clustering techniques and group contribution methods are combined to enable simultaneous consideration of process performance requirements and molecular property constraints. Using this methodology, the process design problem is solved to identify the property targets corresponding to the desired process performance. A significant advantage of the developed methodology is that for problems that can be satisfactorily described by only three properties, the process and mo...

  6. An approach of molecular orbital calculations to process plasmas

    International Nuclear Information System (INIS)

    Remarkable progresses in the development of personal computers and molecular orbital methods have made it possible the calculation of complicated properties of molecules, which has been impossible so far. On the other hand, the plasma process such as reactive ion etching has been development while many plasma phenomena being unsolved. For the further development of the process, it is essential to make basic phenomena and problems in the plasma process clear. In the present article, an introduction to molecular orbital calculations is being presented for convenience of beginners in this field. (J.P.N.)

  7. 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 century

  8. Orbital Energy Levels in Molecular Hydrogen. A Simple Approach.

    Science.gov (United States)

    Willis, Christopher J.

    1988-01-01

    Described are the energetics involved in the formation of molecular hydrogen using concepts that should be familiar to students beginning the study of molecular orbital theory. Emphasized are experimental data on ionization energies. Included are two-electron atomic and molecular systems. (CW)

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

    Science.gov (United States)

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

    2013-01-01

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

  10. Modulation of Energy Conversion Processes in Carbonaceous Molecular Bearings.

    Science.gov (United States)

    Hitosugi, Shunpei; Ohkubo, Kei; Kawashima, Yuki; Matsuno, Taisuke; Kamata, Sho; Nakamura, Kosuke; Kono, Hirohiko; Sato, Sota; Fukuzumi, Shunichi; Isobe, Hiroyuki

    2015-11-01

    The energetics and photodynamics of carbonaceous molecular bearings with discrete molecular structures were investigated. A series of supramolecular bearings comprising belt-persistent tubular cycloarylene and fullerene molecules accepted photonic stimuli to afford charge-separated species via a photoinduced electron transfer process. The energy conversion processes associated with the photoexcitation, however, differed depending on the molecular structure. A ?-lengthened tubular molecule allowed for the emergence of an intermediary triplet excited state at the bearing, which should lead to an energy conversion to thermal energy. On the other hand, low-lying charge-separated species induced by an endohedral lithium ion in fullerene enabled back electron transfer processes to occur without involving triplet excited species. The structure-photodynamics relationship was analyzed in terms of the Marcus theory to reveal a large electronic coupling in this dynamic supramolecular system. PMID:26195132

  11. Simulation and dynamics of entropy-driven, molecular self-assembly processes

    International Nuclear Information System (INIS)

    Molecular self-assembly is frequently found to generate higher-order functional structures in biochemical systems. One such example is the self-assembly of lipids in aqueous solution forming membranes, micelles, and vesicles; another is the dynamic formation and rearrangement of the cytoskeleton. These processes are often driven by local, short-range forces and therefore the dynamics is solely based on local interactions. In this paper, we introduce a cellular automata based simulation, the lattice molecular automaton, in which data structures, representing different molecular entities such as water and hydrophilic and hydrophobic monomers, share locally propagated force information on a hexagonal, two-dimensional lattice. The purpose of this level of description is the simulation of entropic and enthalpic flows in a microcanonical, molecular ensemble to gain insight about entropy-driven processes in molecular many-particle systems. Three applications are shown, i.e., modeling structural features of a polar solvent, cluster formation of hydrophobic monomers in a polar environment, and the self-assembly of polymers. Processes leading to phase separation on a molecular level are discussed. A thorough discussion of the computational details, advantages, and limitations of the lattice molecular automaton approach is given elsewhere [B. Mayer and S. Rasmussen (unpublished)]. copyright 1997 The American Physical Society

  12. 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.

  13. 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.

  14. Biodiversity at the Ecosystem Level - Patterns and Processes

    DEFF Research Database (Denmark)

    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....

  15. Processing method of high level radioactive solution

    International Nuclear Information System (INIS)

    A reagent which acts on zirconium to form precipitates is added to zirconium contained in a solution of spent nuclear fuels or a high level radioactive solution generated along with reprocessing. As the reagent, phosphoric acid, molybdic acid, telluric acid or salts thereof, namely, phosphate, molybdate and tellurate can be used. In addition, if the addition of these reagents and heat treatment are joined, formation of precipitates can be promoted. According to this method, zirconium present in the high level radioactive solution in the form of fine precipitates, colloid or in a dissolved state can be converted to easily removable precipitates without losing safety or applying significant effects on co-existent elements. (T.M.)

  16. Solidification process for high level radioactive waste

    International Nuclear Information System (INIS)

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

  17. Low-level nitrate waste process development

    International Nuclear Information System (INIS)

    Thermal and chemical methods for denitrification of nitrate wastes have been investigated. Experiments were conducted using a high temperature fluid wall reactor to determine its nitrate/nitrite destruction efficiency on simulated Rocky Flats Plant and Savannah River Plant waste streams. These streams included nitrate contaminated soils and feeds containing surrogate fission-products. Various additives were tested to enhance nitrate destruction, reduce NO/sub x/ off-gas generation, and produce an acceptable final waste form. In addition, testing was completed with actual Rocky Flats Plant nitrate wastes on an aqueous process consisting of formic and sulfuric acid reflux, followed by evaporation of the liquid to dryness. Experimental results are discussed and conclusions are presented on both the thermal and the aqueous processes. An update of an earlier survey on nitrate waste generation and inventories at DOE facilities is also provided

  18. Spectroscopic studies of the molecular imprinting self-assembly process.

    Science.gov (United States)

    Svenson, J; Andersson, H S; Piletsky, S A; Nicholls, I A

    1998-01-01

    A method for the rapid estimation of the extent of complex formation in molecular imprinting prepolymerization mixtures is described. By the use of a UV spectroscopy titration procedure, apparent binding constants for such self-assembly processes have been obtained. This method was used for comparison of the interactions between a dipeptide template (N-acetyl-L-phenylalaninyl-L-tryptophanyl methyl ester) and the functional monomer methacrylic acid, and the monomer analogues acetic acid and trifluoroacetic acid. The importance of template-monomer association during the molecular imprinting prepolymerization phase is discussed with respect to the systems studied. PMID:10076812

  19. 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)

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

    International Nuclear Information System (INIS)

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

  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. Atomic and molecular processes in JT-60U divertor plasmas

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-01-01

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

  3. 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.

  4. Molecular-Level Design of Heterogeneous Chiral Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Francisco Zaera

    2012-03-21

    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.

  5. Electron impact atomic and molecular processes - theoretical and application highlights

    International Nuclear Information System (INIS)

    Electron impact atomic/molecular scattering is an established but ever growing field of multidisciplinary theoretical and experimental research. This is so because the impact processes are found to take place in a wide variety of natural and man-made systems. There has long since been a fundamental as well as applied interest in this area of atomic and molecular Physics. The key quantities employed in interpreting the impact phenomena are cross sections, differential as well as total, which exhibit the characteristics of the target and the collision energy. In this article, the author discussed some aspects of electron -atom and electron - molecule collisions, that result into elastic and various inelastic processes. Theoretical highlights along with a few results are presented here as a preliminary account

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

    OpenAIRE

    TAMASCELLI, DARIO; Dambrosio, Francesco S.; Conte, Riccardo; Ceotto, Michele

    2013-01-01

    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 perfect...

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

    OpenAIRE

    O'Brien, Cathal P.; Finn, Stephen P

    2014-01-01

    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 devi...

  8. A Study of molecular cooling via Sisyphus processes

    OpenAIRE

    Comparat, Daniel

    2014-01-01

    We present a study of Sisyphus cooling of molecules: the scattering of a single-photon remove a substantial amount of the molecular kinetic energy and an optical pumping step allow to repeat the process. A review of the produced cold molecules so far indicates that the method can be implemented for most of them, making it a promising method able to produce a large sample of molecules at sub-mK temperature. Considerations of the required experimental parameters, for instance ...

  9. Molecular link between BRCA1 protein levels and obesity

    Science.gov (United States)

    NCI researchers have defined a possible molecular link between breast cancer risk and obesity. New study results show that a protein called C-terminal binding protein (CtBP) acts to control a gene linked to breast cancer risk in rapidly growing cells by m

  10. Evidence for atomic processes in molecular valence double ionization

    International Nuclear Information System (INIS)

    Complete molecular valence-electron spectra were measured for CO. Unexpectedly, discrete lines at low kinetic energies were found, superimposed on a continuous energy spectrum representing direct double-ionization processes. The appearance of these lines is discussed in the context of the formation of the C++O+ ion pair near its associated threshold at 38.4 eV. It is ascribed to valence-excited repulsive (CO+)* states, which dissociate to a large part rapidly into atomic fragments before electronic relaxation takes place. From our spectra, partial cross sections for the different processes leading to dissociative valence double ionization are derived

  11. 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.

  12. Information processing by simple molecular motifs and susceptibility to noise.

    Science.gov (United States)

    Mc Mahon, Siobhan S; Lenive, Oleg; Filippi, Sarah; Stumpf, Michael P H

    2015-09-01

    Biological organisms rely on their ability to sense and respond appropriately to their environment. The molecular mechanisms that facilitate these essential processes are however subject to a range of random effects and stochastic processes, which jointly affect the reliability of information transmission between receptors and, for example, the physiological downstream response. Information is mathematically defined in terms of the entropy; and the extent of information flowing across an information channel or signalling system is typically measured by the 'mutual information', or the reduction in the uncertainty about the output once the input signal is known. Here, we quantify how extrinsic and intrinsic noise affects the transmission of simple signals along simple motifs of molecular interaction networks. Even for very simple systems, the effects of the different sources of variability alone and in combination can give rise to bewildering complexity. In particular, extrinsic variability is apt to generate 'apparent' information that can, in extreme cases, mask the actual information that for a single system would flow between the different molecular components making up cellular signalling pathways. We show how this artificial inflation in apparent information arises and how the effects of different types of noise alone and in combination can be understood. PMID:26333812

  13. Boolean and fuzzy logic implemented at the molecular level

    Science.gov (United States)

    Gentili, Pier Luigi

    2007-07-01

    In this work, it is shown how to implement both hard and soft computing by means of two structurally related heterocyclic compounds: flindersine (FL) and 6(5H)-phenanthridinone (PH). Since FL and PH have a carbonyl group in their molecular skeletons, they exhibit Proximity Effects in their photophysics. In other words, they have an emission power that can be modulated through external inputs such as temperature ( T) and hydrogen-bonding donation (HBD) ability of solvents. This phenomenology can be exploited to implement both crisp and fuzzy logic. Fuzzy Logic Systems (FLSs) wherein the antecedents of the rules are connected through the AND operator, are built by both the Mamdani's and Sugeno's models. Finally, they are adopted as approximators of the proximity effect phenomenon and tested for their prediction capabilities. Moreover, FL as photochromic compound is also a multiply configurable crisp logic molecular element.

  14. 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.

  15. Molecular Level Studies of the Metal/Atmosphere Interface

    OpenAIRE

    Weissenrieder, Jonas

    2003-01-01

    The chemistry andphysics involved at the metal/atmosphereinterface is interesting both from a fundamental and an appliedperspective. Since iron is the most important of all metalsthis interface is of particular interest. The objective withthis thesis is to obtain new information on a molecular levelof the iron/atmosphere interface with a special emphasis on theinitial atmospheric corrosion. The work presented herein combines a large variety ofdifferent analytical surface science techniques. B...

  16. Biotin Sensing at the Molecular Level13

    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...

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

    Czech Academy of Sciences Publication Activity Database

    N?mcov, Pavla; H?ibov, Eva; Valrik, Miroslav; Doleel, 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

  18. 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

  19. Effect of processing on carbon molecular sieve structure and performance

    KAUST Repository

    Das, Mita

    2010-11-01

    Sub-micron sized carbon molecular sieve (CMS) materials were produced via ball milling for subsequent use in hybrid material formation. A detailed analysis of the effects of the milling process in the presence of different milling environments is reported. The milling process apparently alters the molecular scale structure and properties of the carbon material. Three cases: unmilled, air milled and nitrogen milled, were analyzed in this work. The property changes were probed using equilibrium sorption experiments with different gases. Furthermore, WAXD and BET results also showed differences between milling processes. Finally in order to improve the interfacial polymer-sieve region of hybrid membranes, the CMS surface was chemically modified with a linkage unit capable of covalently bonding the polymer to the sieve. A published single-wall carbon nanotube (SWCNTs) modification method was adopted to attach a primary aromatic amine to the surface. Several aspects including rigidity, chemical composition, bulky groups and length were considered in selecting the preferred linkage unit. Fortunately kinetic and equilibrium sorption properties of the modified sieves showed very little difference from unmodified samples, suggesting that the linkage unit is not excessively filling or obstructing access to the pores of the CMSs during the modification process. © 2010 Elsevier Ltd. All rights reserved.

  20. Limitations and improvements upon the two-level approximation for molecular nonlinear optics

    Science.gov (United States)

    Andrews, David L.; Bradshaw, David S.; Coles, Matt M.

    2011-03-01

    When parametric nonlinear processes are employed in the cause of efficient optical frequency conversion, the media involved are generally subjected to substantially off-resonant input radiation. As such, it is usually only electronic ground states of the conversion material that are significantly populated; higher levels are engaged only in the capacity of virtual states, and it is frequently assumed that just one such state dominates in determining the response. Calculating the nonlinear optical susceptibilities of molecules on this basis, excluding all but the ground and one excited state in a sum-over-states formulation, signifies the adoption of a two-level model, a technique that is widely deployed in the calculation and analysis of nonlinear optical properties. The two-level model offers tractable and physically simple representations of molecular response, including wavelength dependence; it is also the origin of the widely applied 'push-pull' approach to designing optically nonlinear chromophores. By contrast, direct ab initio calculations of optical susceptibility are commonly frustrated by a complete failure to determine such dispersion features. However, caution is required; the two-level model can deliver potentially misleading results if it is applied without regard to the criteria for its validity, especially when molecular excited states are significantly populated. On the basis of a precise, quantum electrodynamical basis for the theory, we explore in detail why there are grounds for questioning the general validity of two-level calculations in nonlinear optics; we assess the criteria for high frequency conversion efficiency and provide a new graphical method to assist in determining the applicability of a two-level model for hyperpolarizability calculations. Lastly, this paper also explores the applicability and detailed conditions for the two-level model for electronically excited molecules, identifying problematic results and providing tractable methods for improving the accuracy of calculations on real molecule-photon interactions.

  1. 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.

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

    Science.gov (United States)

    O'Brien, Cathal P; Finn, Stephen P

    2014-01-01

    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. PMID:25988159

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

    DEFF Research Database (Denmark)

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

    2001-01-01

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

  4. Two Molecular Information Processing Systems Based on Catalytic Nucleic Acids

    Science.gov (United States)

    Stojanovic, Milan

    Mixtures of molecules are capable of powerful information processing [1]. This statement is in the following way self-evident: it is a hierarchically organized complex mixture of molecules that is formulating it to other similarly organized mixtures of molecules. By making such a statement I am not endorsing the extreme forms of reductionism; rather, I am making what I think is a small first step towards harnessing information processing prowess of molecules and, hopefully, overcoming some limitations of more traditional computing paradigms. There are different ideas on how to understand and use molecular information processing abilities and I will list some below. My list is far from inclusive, and delineations are far from clear-cut; whenever available, I will provide examples from our research efforts. I should stress, for a computer science audience that I am a chemist. Thus, my approach may have much different focus and mathematical rigor, then if it would be taken by a computer scientist.

  5. Entendendo o Processo Molecular da Tumorignese / Understanding the Molecular Process of Tumorigenesis

    Scientific Electronic Library Online (English)

    Laura Sterian, Ward.

    2002-08-01

    Full Text Available Nos ltimos 25 anos, o reconhecimento dos mecanismos gentico-moleculares implicados na gnese e na progresso do cncer tem permitido obter novos mtodos de diagnstico e de acompanhamento, redirecionando de forma drstica a teraputica do paciente com neoplasia. Alguns marcadores moleculares j es [...] to sendo utilizados na rotina e devero prover testes sensveis e especficos para o diagnstico precoce, estadiamento e acompanhamento do paciente com cncer. As caractersticas moleculares de cada tumor devero permitir predio do seu comportamento, ajudando a delinear estratgias teraputicas mais efetivas. Apresentamos de forma didtica os principais mecanismos controladores do ciclo celular e do crescimento, definindo a importncia de oncogenes erroneamente ativados e de genes supressores tumorais perdidos ou no-funcionantes, dos genes envolvidos na programao e manuteno da vida celular e de outros genes que atuam no processo de tumorignese. Os mecanismos de progresso tumoral, invaso e metastatizao distncia so revistos enfatizando-se a aplicao prtica do conhecimento a respeito de tais mecanismos. Lembramos o papel da instabilidade gentica e dos fenmenos epigenticos na definio fenotpica do cncer, sugerindo as aplicaes da gentica molecular na terapia gnica do cncer. 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.

  6. Ab-initio molecular treatment of the symmetric Mg2+-Mg charge transfer process

    Science.gov (United States)

    Amami, M.; Moussa, A.; Zaidi, A.; Lahmar, S.; Bacchus-Montabonel, M. C.

    2016-02-01

    Potential energy curves of the MgMg2+ molecular system in the lowest electronic states as well as radial and rotational couplings between these states are obtained from ab-initio calculations at the CASSCF/MRCI level of theory using large basis sets. These data are used to investigate, via the semi-classical molecular close coupling method, the single symmetric charge transfer processes of Mg2+-Mg collisions in the [1.0-650] keV laboratory energy range. Total and partial cross sections for the expected capture channels are calculated and compared with the available experimental and theoretical results.

  7. Eleven Levels of Spinous Process Fractures in Thoracolumbar Spine

    OpenAIRE

    Kim, Whoan Jeang; Chi, Yong Joo; Park, Kyung Hoon; Choy, Won Sik

    2014-01-01

    Cases of over 5-level spinous process fractures are extremely rare. Thoracolumbar region of spine is superimposed on ribs; and as such additional studies such as computerized tomography are needed to diagnose fractures in this region. We report a case of 11 contiguous level thoracolumbar spinous process fractures, which has been treated conservatively.

  8. Process for attaching molecular wires and devices to carbon nanotubes and compositions thereof

    Science.gov (United States)

    Tour, James M. (Inventor); Bahr, Jeffrey L. (Inventor); Yang, Jiping (Inventor)

    2008-01-01

    The present invention is directed towards processes for covalently attaching molecular wires and molecular electronic devices to carbon nanotubes and compositions thereof. Such processes utilize diazonium chemistry to bring about this marriage of wire-like nanotubes with molecular wires and molecular electronic devices.

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

    DEFF Research Database (Denmark)

    Kuznetsov, A.M.; Ulstrup, Jens

    2002-01-01

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

  10. Simulation analysis of molecular laser isotope separation process for safeguards design

    International Nuclear Information System (INIS)

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

  11. Levels of processing: the evolution of a framework

    Scientific Electronic Library Online (English)

    Roberta, Ekuni; Leonardo Jos, 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.

  12. Molecular dynamics simulations of cluster fission and fusion processes

    DEFF Research Database (Denmark)

    Lyalin, Andrey G.; Obolensky, Oleg I.; Solov'yov, Ilia; Solov'yov, Andrey V.; Greiner, Walter

    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......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...

  13. 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 C, 130 C, and 140 C) were carried out in a KDL4 (UIC) molecular distillation apparatus to verify the model.

  14. Molecular processes of transgenerational acclimation to a warming ocean

    KAUST Repository

    Veilleux, Heather D.

    2015-07-20

    Some animals have the remarkable capacity to acclimate across generations to projected future climate change1, 2, 3, 4; however, the underlying molecular processes are unknown. We sequenced and assembled de novo transcriptomes of adult tropical reef fish exposed developmentally or transgenerationally to projected future ocean temperatures and correlated the resulting expression profiles with acclimated metabolic traits from the same fish. We identified 69 contigs representing 53 key genes involved in thermal acclimation of aerobic capacity. Metabolic genes were among the most upregulated transgenerationally, suggesting shifts in energy production for maintaining performance at elevated temperatures. Furthermore, immune- and stress-responsive genes were upregulated transgenerationally, indicating a new complement of genes allowing the second generation of fish to better cope with elevated temperatures. Other differentially expressed genes were involved with tissue development and transcriptional regulation. Overall, we found a similar suite of differentially expressed genes among developmental and transgenerational treatments. Heat-shock protein genes were surprisingly unresponsive, indicating that short-term heat-stress responses may not be a good indicator of long-term acclimation capacity. Our results are the first to reveal the molecular processes that may enable marine fishes to adjust to a future warmer environment over multiple generations.

  15. Molecular processes of transgenerational acclimation to a warming ocean

    Science.gov (United States)

    Veilleux, Heather D.; Ryu, Taewoo; Donelson, Jennifer M.; van Herwerden, Lynne; Seridi, Loqmane; Ghosheh, Yanal; Berumen, Michael L.; Leggat, William; Ravasi, Timothy; Munday, Philip L.

    2015-12-01

    Some animals have the remarkable capacity to acclimate across generations to projected future climate change; however, the underlying molecular processes are unknown. We sequenced and assembled de novo transcriptomes of adult tropical reef fish exposed developmentally or transgenerationally to projected future ocean temperatures and correlated the resulting expression profiles with acclimated metabolic traits from the same fish. We identified 69 contigs representing 53 key genes involved in thermal acclimation of aerobic capacity. Metabolic genes were among the most upregulated transgenerationally, suggesting shifts in energy production for maintaining performance at elevated temperatures. Furthermore, immune- and stress-responsive genes were upregulated transgenerationally, indicating a new complement of genes allowing the second generation of fish to better cope with elevated temperatures. Other differentially expressed genes were involved with tissue development and transcriptional regulation. Overall, we found a similar suite of differentially expressed genes among developmental and transgenerational treatments. Heat-shock protein genes were surprisingly unresponsive, indicating that short-term heat-stress responses may not be a good indicator of long-term acclimation capacity. Our results are the first to reveal the molecular processes that may enable marine fishes to adjust to a future warmer environment over multiple generations.

  16. 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.

  17. The Building Blocks of Materials: Gathering Knowledge at the Molecular Level

    Science.gov (United States)

    2003-01-01

    Two start-up positions were created within SD46 to pursue developments in the rapidly expanding areas of biomineralization and nano-technology. As envisioned by Dr. Sandor Lehoczy, the new laboratories to be developed must have the capacity to investigate not only processes associated with the self-assembly of molecules but also the examination of self-assembled structures. For these purposes, laboratories capable of performing the intended function, particularly light scattering spectroscopy and atomic force microscopy were created. What follows then are recent advances arising from the development of these new laboratories. With the implementation of the Atomic Force Microscopy Facility, examples of investigations that determine a correlation between the molecular structure of materials and their macroscopic physical properties are provided. In addition, examples of investigations with particular emphasis on the physical properties of protein crystals, at the molecular level, and subsequent macroscopic characteristics are as provided. Finally, progress in fabrication of technology at the nano-scale levels at the developmental stage is also presented.

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

    Czech Academy of Sciences Publication Activity Database

    Lsal, Martin

    Bratislava : Slovak Society of Chemical Engineering, 2006 - (tefuca, V.; Marko, J.), s. 288 ISBN 80-227-2409-2. [International Conference of Slovak Society of Chemical Engineering /33./. Tatransk 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

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

    Science.gov (United States)

    Bein, Thomas (Albuquerque, NM); Brown, Kelly D. (Albuquerque, NM); Frye, Gregory C. (Albuquerque, NM); Brinker, Charles J. (Albuquerque, NM)

    1992-01-01

    The invention relates to a selective chemical sensor for selective detection of chemical entities even at the nanogram level. The invention further relates to methods of using the sensor. The sensor comprises: (a) a piezoelectric substrate capable of detecting mass changes resulting from adsorption of material thereon; and (b) a coating applied to the substrate, which selectively sorbs chemical entities of a size smaller than a preselected magnitude.

  20. Managing the high level waste nuclear regulatory commission licensing process

    International Nuclear Information System (INIS)

    This paper reports that the process for obtaining Nuclear Regulatory Commission permits for the high level waste storage facility is basically the same process commercial nuclear power plants followed to obtain construction permits and operating licenses for their facilities. Therefore, the experience from licensing commercial reactors can be applied to the high level waste facility. Proper management of the licensing process will be the key to the successful project. The management of the licensing process was categorized into four areas as follows: responsibility, organization, communication and documentation. Drawing on experience from nuclear power plant licensing and basic management principles, the management requirement for successfully accomplishing the project goals are discussed

  1. 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.)

  2. 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...

  3. 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.

  4. 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

  5. Low-energy electron-collision processes in molecular chlorine

    International Nuclear Information System (INIS)

    The results of close-coupling calculations using the complex Kohn variational method are reported for a variety of low-energy electron-collision processes involving molecular chlorine. We report cross sections for elastic scattering and momentum transfer, as well as dissociative excitation of the five lowest electronically excited states (1,3?u, 1,3?g, 3?u+) which are formed by promoting an occupied valence electron into an antibonding (5?u) orbital. We also report cross sections for the excitation of the lowest bound optically allowed states in Cl2. The cross sections, especially at very low energies, are found to depend sensitively on both target polarization and a proper balance of correlation effects in the N- and (N+1)-electron systems. Comparison is made between the results of this study and the limited body of experimental results available for this system

  6. Energy conversion processes based on molecular excited states

    Science.gov (United States)

    Meyer, T. J.

    1987-03-01

    The major emphasis of our DOE-supported research efforts remains the use of molecular excited states in energy conversion processes. In the past year we have made significant progress in the distinct areas of: (1) electronic structure, photophysical and photochemical properties of MLCT-based excited states, (2) design and characterization of metallopolymeric films as a basis for photoelectrodes containing MLCT-based chromophores, and (3) excited state photoelectrochemical cells based on excited state redox quenching. We have continued to develop synthetic routes to new MLCT excited states, most recently to a series of complexes. Systematic variations (from electron-donating to electron-withdrawing properties) allow control to be gained over changes in emission energies (E sub em), excited state redox potentials, ground state absorption energies, and radiative and nonradiative decay rate constants and perhaps, most importantly, open up two new families of excited states for photoredox applications.

  7. Collision processes of electrons with molecular hydrogen ions

    International Nuclear Information System (INIS)

    Collision processes of electrons with trapped ions of mass numbers 1, 2, 3, 5, 7, 10, 14 and 20 are investigated in the concentric electron-beam device. Trapping characteristics are measured and lead to the conclusion that all the ions in the trap are hydrogenic. Cross section functions for the electron impact dissociation of H2+, H3+ and H5+ are measured. the shape of the H2+ dissociation function indicates that the molecular ions are trapped for a sufficiently long time for vibrational decay to upsilon = 0 to occur. There is good agreement between the present low energy H3+ dissociation data and previous work. Dissociation cross sections for H5+ and the temperature dependence of the e-H5+ recombination rate are measured. The latter is in good agreement with previous room temperature data and facilitates the prediction of the recombination rate in the Jovian ionosphere. (author)

  8. Discovering disease-disease associations by fusing systems-level molecular data

    OpenAIRE

    2013-01-01

    The advent of genome-scale genetic and genomic studies allows new insight into disease classification. Recently, a shift was made from linking diseases simply based on their shared genes towards systems-level integration of molecular data. Here, we aim to find relationships between diseases based on evidence from fusing all available molecular interaction and ontology data. We propose a multi-level hierarchy of disease classes that significantly overlaps with existing disease classification. ...

  9. Protein Fibrillar Nanopolymers: Molecular-Level Insights into Their Structural, Physical and Mechanical Properties

    Science.gov (United States)

    Trusova, Valeriya M.

    2015-09-01

    Amyloid fibrils represent a generic class of mechanically strong and stable biomaterials with extremely advantageous properties. Although amyloids were initially associated only with severe neurological disorders, the role of these structures nowadays is shifting from health debilitating to highly beneficial both in biomedical and technological aspects. Intensive involvement of fibrillar assemblies into the wide range of pathogenic and functional processes strongly necessitate the molecular level characterization of the structural, physical and elastic features of protein nanofibrils. In the present contribution, we made an attempt to highlight the up-to-date progress in the understanding of amyloid properties from the polymer physics standpoint. The fundamental insights into protein fibril behavior are essential not only for development of therapeutic strategies to combat the protein misfolding disorders but also for rational and precise design of novel biodegradable protein-based nanopolymers.

  10. Radiation studies at the physical, molecular, cellular and macrocolony level

    International Nuclear Information System (INIS)

    Radiation effects in stationary yeast cells have been studied after irradiation with 30 MeV electrons, X-rays and alpha-particles. At the level of cfa alpha particles and X-rays cause more irreparable damage than 30 MeV electrons. The behaviour of an irradiated yeast cell population is studied by microscopic observation of single cells followed by computer analysis of the stored optical data. During the first four generations after irradiation the second cell division is the critical one for survival of the cells. The production of DNA dsbs in irradiated yeast cells is investigated by velocity sedimentation in a sucrose gradient. The average number of dsbs as a function of absorbed dose is determined by computer simulation of random breakage applied to the control DNA and by fitting these curves to the DNA profiles obtained from irradiated cells. It is shown that dsbs are exclusively produced by direct radiation effects. Changes in number of dsbs during liquid holding recovery are investigated and are compared with changes in cfa. The possible significance of certain energy deposition patterns of electrons, X-rays and alpha particles for the different radiation induced biological effects is estimated

  11. 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

  12. High Level Waste (HLW) Feed Process Control Strategy

    Energy Technology Data Exchange (ETDEWEB)

    STAEHR, T.W.

    2000-06-14

    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.

  13. 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 LennardJones clusters have been investigated for cluster sizes of up to 150 atoms. All known global minima structures of the LennardJones clusters are found.

  14. Molecular rocket and implantation reactions: shock-induced phenomena at atomic and molecular levels

    International Nuclear Information System (INIS)

    Molecular rocket reactions are unique but contain important features. This paper deals with their relation to shock-induced phenomena. Extraction of metallocene from a cavity of cyclodextrin is assisted by shock of collision and is followed by rearrangement reactions. Severeness of the rearrangement depends on energy. Collisions of implanted atoms also extract metallocene molecules from inclusion compounds to cause rearrangement reactions. This is ascribed to a shock-induced phenomenon. Collision cascade enhancement of the yield in implantation reaction is closely related to shock waves generated after the implanted atom. Forward pressure pushes the implanted atom and reactant molecules into the microcrack formed in implantation in metal ?-diketonates. In the case of metallocene implantation, however, another mechanism involving an increased number of replacement paths should be considered. (orig.)

  15. 0-level Vacuum Packaging RT Process for MEMS Resonators

    CERN Document Server

    Abel, 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.

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

    Science.gov (United States)

    Norln, L

    2014-09-01

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

  17. Reducing process noise in superconducting helium liquid level probes

    Energy Technology Data Exchange (ETDEWEB)

    Brubaker, J.

    1995-03-01

    This memo presents methods to reduce the process noise accompanying the use of superconducting helium liquid level probes in a splashing environment. The development of these methods followed unsatisfactory operation of unmodified, commercially available, level probes used in each of the 24 valve box dewars of Tevatron refrigerators. The dewars function both as reservoirs of refrigeration and as phase separators at the inlet of the cold compressors used in subatmospheric magnet cooling operation.

  18. 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...

  19. 0-level Vacuum Packaging RT Process for MEMS Resonators

    OpenAIRE

    Abel, N.; Grogg, D.; HIBERT, C; F. Casset; 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-e...

  20. Tip-induced gating of molecular levels in carbene-based junctions.

    Science.gov (United States)

    Foti, Giuseppe; Vzquez, Hctor

    2016-03-29

    We study the conductance of N-heterocyclic carbene-based (NHC) molecules on gold by means of first-principles calculations based on density-functional theory and non-equilibrium Green's functions. We consider several tip structures and find a strong dependence of the position of the NHC molecular levels with the atomistic structure of the tip. The position of the lowest unoccupied molecular orbital (LUMO) can change by almost 0.8 eV with tip shape. Through an analysis of the net charge transfer, electron redistribution and work function for each tip structure, we rationalize the LUMO shifts in terms of the sum of the work function and the maximum electrostatic potential arising from charge rearrangement. These differences in the LUMO position, effectively gating the molecular levels, result in large conductance variations. These findings open the way to modulating the conductance of NHC-based molecular circuits through the controlled design of the tip atomistic structure. PMID:26891059

  1. Tip-induced gating of molecular levels in carbene-based junctions

    Science.gov (United States)

    Foti, Giuseppe; Vázquez, Héctor

    2016-03-01

    We study the conductance of N-heterocyclic carbene-based (NHC) molecules on gold by means of first-principles calculations based on density-functional theory and non-equilibrium Green’s functions. We consider several tip structures and find a strong dependence of the position of the NHC molecular levels with the atomistic structure of the tip. The position of the lowest unoccupied molecular orbital (LUMO) can change by almost 0.8 eV with tip shape. Through an analysis of the net charge transfer, electron redistribution and work function for each tip structure, we rationalize the LUMO shifts in terms of the sum of the work function and the maximum electrostatic potential arising from charge rearrangement. These differences in the LUMO position, effectively gating the molecular levels, result in large conductance variations. These findings open the way to modulating the conductance of NHC-based molecular circuits through the controlled design of the tip atomistic structure.

  2. Evaluation of tocopherol recovery through simulation of molecular distillation process.

    Science.gov (United States)

    Moraes, E B; Batistella, C B; Alvarez, M E Torres; Filho, Rubens Maciel; Maciel, M R Wolf

    2004-01-01

    DISMOL simulator was used to determine the best possible operating conditions to guide, in future studies, experimental works. This simulator needs several physical-chemical properties and often it is very difficult to determine them because of the complexity of the involved components. Their determinations must be made through correlations and/or predictions, in order to characterize the system and calculate it. The first try is to have simulation results of a system that later can be validated with experimental data. To implement, in the simulator, the necessary parameters of complex systems is a difficult task. In this work, we aimed to determe these properties in order to evaluate the tocopherol (vitamin E) recovery using a DISMOL simulator. The raw material used was the crude deodorizer distillate of soya oil. With this procedure, it is possible to determine the best operating conditions for experimental works and to evaluate the process in the separation of new systems, analyzing the profiles obtained from these simulations for the falling film molecular distillator. PMID:15054286

  3. 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.

  4. Dynamics of Molecular Motors with Finite Processivity on Heterogeneous Tracks

    CERN Document Server

    Kafri, Y; Nelson, D R; Kafri, Yariv; Lubensky, David K.; Nelson, David R.

    2004-01-01

    The dynamics of molecular motors which occasionally detach from a heterogeneous track like DNA or RNA is considered. Motivated by recent single molecule experiments, we study a simple model for a motor moving along a disordered track using chemical energy while an external force opposes its motion. The motors also have finite processivity, i.e., they can leave the track with a position dependent rate. We show that the response of the system to disorder in the hopping off rate depends on the value of the external force. For most values of the external force, strong disorder causes the motors which survive for long times on the track to be localized at preferred positions. However, near the stall force, localization occurs for any amount of disorder. Existence of localized states near the top of the band implies a stretched exponential contribution to the decay of the survival probability. To obtain these results, we study the complex eigenvalue spectrum of the time evolution operator. A similar spectral analys...

  5. Nanoarchitectonics for Dynamic Functional Materials from Atomic-/Molecular-Level Manipulation to Macroscopic Action.

    Science.gov (United States)

    Ariga, Katsuhiko; Li, Junbai; Fei, Jinbo; Ji, Qingmin; Hill, Jonathan P

    2016-02-01

    Objects in all dimensions are subject to translational dynamism and dynamic mutual interactions, and the ability to exert control over these events is one of the keys to the synthesis of functional materials. For the development of materials with truly dynamic functionalities, a paradigm shift from "nanotechnology" to "nanoarchitectonics" is proposed, with the aim of design and preparation of functional materials through dynamic harmonization of atomic-/molecular-level manipulation and control, chemical nanofabrication, self-organization, and field-controlled organization. Here, various examples of dynamic functional materials are presented from the atom/molecular-level to macroscopic dimensions. These systems, including atomic switches, molecular machines, molecular shuttles, motional crystals, metal-organic frameworks, layered assemblies, gels, supramolecular assemblies of biomaterials, DNA origami, hollow silica capsules, and mesoporous materials, are described according to their various dynamic functions, which include short-term plasticity, long-term potentiation, molecular manipulation, switchable catalysis, self-healing properties, supramolecular chirality, morphological control, drug storage and release, light-harvesting, mechanochemical transduction, molecular tuning molecular recognition, hand-operated nanotechnology. PMID:26436552

  6. Molecular-Level Simulation of Reacting Systems in Bulk and Confinement.

    Czech Academy of Sciences Publication Activity Database

    Lsal, Martin; Smith, W. R.; Brennan, J. K.

    Praha : Process Engineering Publisher, 2004, s. 502. ISBN 80-86059-40-5. [International Congress of Chemical and Process Engineering CHISA 2004 /16./. Praha (CZ), 22.08.2004-26.08.2004] Institutional research plan: CEZ:AV0Z4072921 Keywords : molecular simulation * bulk and confinement * reacting systems Subject RIV: CF - Physical ; Theoretical Chemistry

  7. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Stegen, G.E.

    1996-02-13

    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.

  9. 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

  10. CELLmicrocosmos - Integrativecellmodelingatthe molecular,mesoscopicandfunctionallevel

    OpenAIRE

    Sommer, Bjrn

    2012-01-01

    The modeling of cells is an important application area of Systems Biology. In the context of this work, three cytological levels are defined: the mesoscopic, the molecular and the functional level. A number of related approaches which are quite diverse will be introduced during this work which can be categorized into these disciplines. But none of these approaches covers all areas. In this work, the combination of all three aforementioned cytological levels is presented, realized by the CELLm...

  11. Free energy calculations using dual-level Born-Oppenheimer molecular dynamics

    Science.gov (United States)

    Retegan, Marius; Martins-Costa, Marilia; Ruiz-Lpez, Manuel F.

    2010-08-01

    We describe an efficient and accurate method to compute free energy changes in complex chemical systems that cannot be described through classical molecular dynamics simulations, examples of which are chemical and photochemical reactions in solution, enzymes, interfaces, etc. It is based on the use of dual-level Born-Oppenheimer molecular dynamics simulations. A low-level quantum mechanical method is employed to calculate the potential of mean force through the umbrella sampling technique. Then, a high-level quantum mechanical method is used to estimate a free energy correction on selected points of the reaction coordinate using perturbation theory. The precision of the results is comparable to that of ab initio molecular dynamics methods such as the Car-Parrinello approach but the computational cost is much lower, roughly by two to three orders of magnitude. The method is illustrated by discussing the association free energy of simple organometallic compounds, although the field of application is very broad.

  12. Free energy calculations using dual-level Born-Oppenheimer molecular dynamics

    International Nuclear Information System (INIS)

    We describe an efficient and accurate method to compute free energy changes in complex chemical systems that cannot be described through classical molecular dynamics simulations, examples of which are chemical and photochemical reactions in solution, enzymes, interfaces, etc. It is based on the use of dual-level Born-Oppenheimer molecular dynamics simulations. A low-level quantum mechanical method is employed to calculate the potential of mean force through the umbrella sampling technique. Then, a high-level quantum mechanical method is used to estimate a free energy correction on selected points of the reaction coordinate using perturbation theory. The precision of the results is comparable to that of ab initio molecular dynamics methods such as the Car-Parrinello approach but the computational cost is much lower, roughly by two to three orders of magnitude. The method is illustrated by discussing the association free energy of simple organometallic compounds, although the field of application is very broad.

  13. 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...

  14. 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.

  15. 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 ...

  16. Calculation of energy levels and wavefunctions of hydrogen molecular ion using B-splines function

    International Nuclear Information System (INIS)

    Energy levels and wavefunctions of the ground state and the first excited state of hydrogen molecular ion are calculated by solving stationary Schrodinger equation with B-splines functions. By adopting nuclear positions as knots of B-splines basis, high accuracy of energy levels of the ground state and the first excited state for hydrogen molecular ion can be reached even for the larger internuclear separations, and our ? dependent radial wavefunctions of the ground state are in a good agreement with those computed from GAUSSIAN chemistry software. (authors)

  17. 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

  18. Molecular processes that handle and mishandle dietary lipids

    OpenAIRE

    Williams, Kevin Jon

    2008-01-01

    Overconsumption of lipid-rich diets, in conjunction with physical inactivity, disables and kills staggering numbers of people worldwide. Recent advances in our molecular understanding of cholesterol and triglyceride transport from the small intestine to the rest of the body provide a detailed picture of the fed/fasted and active/sedentary states. Key surprises include the unexpected nature of many pivotal molecular mediators, as well as their dysregulation but possible reversibility in ob...

  19. Molecular and genetic diversity in the metastatic process of melanoma

    OpenAIRE

    Harbst, Katja; Lauss, Martin; Cirenajwis, Helena; Winter, Christof; Howlin, Jillian; Törngren, Therese; Kvist, Anders; Nodin, Björn; Olsson, Eleonor; Häkkinen, Jari; Jirström, Karin; Staaf, Johan; Lundgren, Lotta; Olsson, Håkan; Ingvar, Christian

    2014-01-01

    Diversity between metastatic melanoma tumours in individual patients is known; however, the molecular and genetic differences remain unclear. To examine the molecular and genetic differences between metastatic tumours, we performed gene-expression profiling of 63 melanoma tumours obtained from 28 patients (two or three tumours/patient), followed by analysis of their mutational landscape, using targeted deep sequencing of 1697 cancer genes and DNA copy number analysis. Gene-expression signatur...

  20. 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

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

    Science.gov (United States)

    Yang, Ruiguo

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

  2. 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

  3. 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.

  4. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-20

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

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

    International Nuclear Information System (INIS)

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

  7. Molecular processes that handle -- and mishandle -- dietary lipids.

    Science.gov (United States)

    Williams, Kevin Jon

    2008-10-01

    Overconsumption of lipid-rich diets, in conjunction with physical inactivity, disables and kills staggering numbers of people worldwide. Recent advances in our molecular understanding of cholesterol and triglyceride transport from the small intestine to the rest of the body provide a detailed picture of the fed/fasted and active/sedentary states. Key surprises include the unexpected nature of many pivotal molecular mediators, as well as their dysregulation - but possible reversibility - in obesity, diabetes, inactivity, and related conditions. These mechanistic insights provide new opportunities to correct dyslipoproteinemia, accelerated atherosclerosis, insulin resistance, and other deadly sequelae of overnutrition and underexertion. PMID:18830418

  8. Understanding molecular weight reduction of starch during heating-shearing processes

    OpenAIRE

    Einde, R.M., van den; Goot, A.J., van der; Boom, R.M.

    2003-01-01

    Recent understanding of the mechanisms underlying the changes in molecular weight of starch as a function of process parameters during thermomechanical treatment, for example extrusion, holds promise towards more effective optimization of thermomechanical processes according to the desired modification of molecular weight. This paper summarizes recent advances in theoretical understanding and experimental methods. Empirical observations from extruder experiments can be better understood on th...

  9. Elucidation of polymer induced DNA condensation. Visualisation at the single molecular level

    International Nuclear Information System (INIS)

    DNA condensation is a phenomenon that has stimulated interest from biologists, physicists, and polymer chemists for decades. At the cellular level, this process is key to the packing of DNA within the nuclear envelope, and the exposure of the appropriate nucleic acid sequences in order for transcription to occur, and proteins to be produced. The advent of gene therapy has led to an invigoration of this subject area. In order to successfully deliver to, and transfect target cells, many delivery vectors condense the therapeutic DNA into small compact particles. The nature of these particles have a considerable influence on the ultimate expression of the administered nucleic acid material. In addition, at its most fundamental, DNA itself is a classical polyelectrolyte polymer, the behaviour of which has applicability to other charged polymeric systems. There are two core interwound themes to this investigation; the visualisation of DNA condensate morphology at ultra-resolution, and the elucidation of the mechanisms of formation of these structures. The technique of atomic force microscopy is central to these investigations. Methodologies have been devised allowing the visualisation of the tertiary structure and conformational behaviour of individual DNA condensates in near in situ conditions. Condensation of the nucleic acid material has been induced by two classes of cation; small molecular cations, like those found within eukaryotic cells, and a range of cationic polymers. The cationic polymers investigated all have considerable potential as gene delivery vectors. The resultant DNA condensates have been assessed and contrasted in terms of their tertiary morphology, lateral dimensions, and structural volume. Assessments have also been made regarding the influence of the molecular architecture of the cationic moiety and the nature of the input nucleic acid material on the resultant DNA condensates. With regard to the elucidation of the mechanisms of DNA condensate formation, this question has been addressed in two ways. Firstly, in an attempt to form intermediates of the condensation process, DNA has been exposed to cationic moieties over a range of cationic charge to DNA nucleotide ratios. The morphologies of the resulting complexes have been analysed, and hypotheses have been constructed, regarding the mechanisms of DNA condensate formation. The second methodology adopted involved the visualisation of the formation of DNA condensates in real time. DNA-cation complexes have been visualised in a near in situ environment, allowing dynamic tertiary conformational change of individual DNA condensates to be observed. The investigations presented here are among the first to utilise atomic force microscopy, operating in an aqueous environment, to elucidate DNA condensate morphology and dynamic conformational change in real time, and to apply atomic force microscopy in the characterisation of potential gene delivery vectors. (author)

  10. SENTINEL-2 Level 1 Products and Image Processing Performances

    Science.gov (United States)

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

    2012-07-01

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

  11. Atmospheric processes on ice nanoparticles in molecular beams.

    Czech Academy of Sciences Publication Activity Database

    Frnk, 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

  12. Coupled processes in NRC high-level waste research

    International Nuclear Information System (INIS)

    The author discusses NRC research effort in support of evaluating license applications for disposal of nuclear waste and for promulgating regulations and issuing guidance documents on nuclear waste management. In order to do this they fund research activities at a number of laboratories, academic institutions, and commercial organizations. One of our research efforts is the coupled processes study. This paper discusses interest in coupled processes and describes the target areas of research efforts over the next few years. The specific research activities relate to the performance objectives of NRC's high-level waste (HLW) regulation and the U.S. Environmental Protection Agency (EPA) HLW standard. The general objective of the research program is to ensure the NRC has a sufficient independent technical base to make sound regulatory decisions

  13. Identification of mycobacteria in peat moss processing plants : application of molecular biology approaches

    Energy Technology Data Exchange (ETDEWEB)

    Cayer, M.P.; Veillette, M.; Pageau, P.; Cormier, Y.; Duchaine, C.; Meriaux, A. [Laval Univ., Quebec City, PQ (Canada). Inst. Universitaire de pneumologie et de cardiologie; Veillette, M.; Meriaux, A.; Cormier, Y. [Laval Univ., Quebec City, PQ (Canada). Dept. of Biology and Microbiology; Hamelin, R.; Bergeron, M.J. [Natural Resources Canada, Sainte-Foy, PQ (Canada). Canadian Forest Service

    2007-01-15

    Health concerns regarding environmental mycobacteria has led to the development of exposure assessment methods for the evaluation of certain workplaces where the presence of these agents is suspected. Hypersensitivity pneumonitis (HP) has been described in peat moss workers who are regularly exposed to significant levels of bioaerosols in peat moss processing plants. Although mycobacteria have been cultured from peat moss, plant workers exposure to mycobacterial bioaerosols has never been studied. This article presented the results of a study that evaluated the presence of mycobacteria in air samples from peat moss processing plants using molecular biology approaches (cloning-sequencing and polymerase chain reaction (PCR)) and the workers exposure using immunoglobin G (IgG) complexes to mycobacteria. It also compared species detected in air samples and in peat moss. Two peat moss processing plants were chosen among 14 previously studied and a total of 49 clones were sequenced. Real-time PCR was also performed on the same air samples to evaluate the airborne concentration of mycobacteria and estimate exposure levels. The article discussed the materials and methods used in the study, the results of the study, and subsequent discussion of the results. It was concluded that peat moss processing plants workers are exposed to mycobacteria in addition to other biological agents. It was suggested that further studies are needed to confirm the specificity of the mycobacterial IgG. 34 refs., 2 tabs., 1 fig.

  14. 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

  15. Oak Ridge Y-12 Plant Emergency Action Level (EAL) Process

    Energy Technology Data Exchange (ETDEWEB)

    Bailiff, E.G.; Bolling, J.D.

    2000-08-01

    This report establishes requirements and standard methods for the development and maintenance of the Emergency Action Level (EAL) Process used by all lead and event contractors for emergency planning and preparedness. The EAL process ensures a technically defensible approach to emergency categorization/classification in accordance with DOE Order 151.1. The instructions provided in this document include methods and requirements for the development and approval of the EAL process. EALs are developed to cover events inside and outside the Y-12 Plant and to allow the Emergency Response Organization (ERO) to classify or reclassify events promptly based on specific indicators. This report is divided into the following 11 subsections: (1) EAL Process, (2) Categorization/Classification System for Operational Emergencies, (3) Development of EALs, (4) Barrier Analysis for EALs, (5) Symptom-Based and Event-Based EALs, (6) Other Considerations, (7) Integration of EALs with Normal and Off-Normal Operations, (8) EAL Manual, (9) Testing EALs for Completeness, (10) Training and Implementation of EALs, and (11) Configuration Management.

  16. 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

  17. Molecular and genetic diversity in the metastatic process of melanoma.

    Science.gov (United States)

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

    2014-05-01

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

  18. 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.

  19. 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)

  20. Polyelectrolytes processing at pilot scale level by electron beam irradiation

    International Nuclear Information System (INIS)

    Three years of research, combined with engineering activities, have culminated in the development of a new method of electron beam processing applicable up to the pilot scale level, namely, the polyelectrolytes (acrylamide - acrylic acid copolymers) electron beam processing. This new radiation processing method has been achieved by bilateral co-operation between the National Institute for Laser, Plasma and Radiation Physics (NILPRP) and the Electrical Design and Research Institute, EDRI - Bucharest. The polyelectrolytes electron beam (EB) processing was put in operation at EDRI, where, recently, an industrial electron accelerator of 2 MeV and 20 kW, manufactured by Institute of Nuclear Physics, Novosibirsk, Russia was installed in a specially designed irradiation facility. Automatic start-up via computer control makes it compatible with industrial processing. According to the first conclusions, which resulted from our experimental research with regard to acrylamide - acrylic acid copolymers production by EB irradiation, the proper physical and chemical characteristics can be well controlled by chemical composition to be treated and by suitable adjustment of absorbed dose and absorbed dose rate. So, it was possible to obtain a very large area of characteristics and therefore a large area of applications. The conversion coefficient is very high (> 98%) and concentration of the residual monomer is under 0.05%. The tests applied to some wastewaters from the vegetable oil plants demonstrated that the fatty substances, matters in suspension, chemical oxygen demand and biological oxygen demand over 5 days were much reduced, in comparison with classical treatment. Also, sedimentation time was around four times smaller and sediment volume was 60% smaller than the values obtained in case of classical treatment. The necessary EB absorbed dose for the acrylamide - acrylic acid aqueous solution polymerization, established by optimization of chemical composition and irradiation conditions, is rather small, of about 1 kGy, that makes the use of electron beam processing very economically attractive in this type of application. Thus, if all auxiliary systems are made and suitable adapted, the estimation of processing rate is 3600 kg/h. The acrylamide - acrylic acid copolymers are used in the range of 4 to 8 g per 1 m3 of wastewater. A vegetable oil plant which processes 100 000 ton/year of sunflower produces about 1 260 000 m3/year wastewater. The necessary amount of polyelectrolytes is 315-630 kg/year. This value can by ensured by our technology in a very short time, from 315 s to 630 s. (authors)

  1. Molecular cytogenetics in an assessment of DNA damage and repair processes

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Carmen Silva

    2004-11-01

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

  3. 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

  4. Atomic and molecular oxygen collision processes over some crystalline solids

    OpenAIRE

    Morn Tejero, Vctor

    2011-01-01

    [cat] Sha realitzat un estudi teric dalguns dels processos qumics elementals de loxigen atmic i molecular sobre les superfcies slides del grafit i de la ?cristobalita. La intenci ha sigut la dampliar el coneixement sobre quin es el comportament dels materials que sempren com a sistemes de protecci trmica en vehicles espacials durant la seva reentrada a latmosfera terrestre. Per entendre millor com tenen lloc aquests processos qumics heterogenis sobre la superfcie del graf...

  5. 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

  6. Landau levels, molecular orbitals, and the Hofstadter butterfly in finite systems

    OpenAIRE

    Analytis, JG; Blundell, SJ; Ardavan, A.

    2004-01-01

    The Hofstadter butterfly is the energy spectrum of an infinite square lattice, plotted as a function of the magnetic field. We illustrate a method of calculating similar spectra for finite lattices in a magnetic field, using methods that consider the appropriate molecular orbitals, and find that the spectra resemble the Hofstadter butterfly. We relate the bonding and antibonding orbitals used to describe small systems to the Landau levels of the infinite system. This approach provides an unus...

  7. Molecular Electronic Level Alignment at Weakly Coupled Organic Film/Metal Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jin; Feng, Min; Dougherty, Daniel B.; Sun, Hao; Petek, Hrvoje

    2014-10-28

    Electronic level alignment at interfaces of molecular materials with inorganic semiconductors and metals controls many interfacial phenomena. How the intrinsic properties of the interacting systems define the electronic structure of their interface remains one of the most important problems in molecular electronics and nanotechnology that can be solved through a combination of surface science experimental techniques and theoretical modeling. In this article, we address this fundamental problem through experimental and computational studies of molecular electronic level alignment of thin films of C6F6 on noble metal surfaces. The unoccupied electronic structure of C6F6 is characterized with single molecule resolution using low-temperature scanning tunneling microscopy-based constant-current distance-voltage spectroscopy. The experiments are performed on several noble metal surfaces with different work functions and distinct surface-normal projected band structures. In parallel, the electronic structures of the quantum wells (QWs) formed by the lowest unoccupied molecular orbital state of the C6F6 monolayer and multilayer films and their alignment with respect to the vacuum level of the metallic substrates are calculated by solving the Schrdinger equation for a semiempirical one-dimensional (1D) potential of the combined system using input from density functional theory. Our analysis shows that the level alignment for C6F6 molecules bound through weak van der Waals interactions to noble metal surfaces is primarily defined by the image potential of metal, the electron affinity of the molecule, and the molecule surface distance. We expect the same factors to determine the interfacial electronic structure for a broad range of molecule/metal interfaces.

  8. Tunable high-power terahertz radiation generation in three-level atomic and molecular systems

    International Nuclear Information System (INIS)

    A scheme is presented for generation of powerful coherent terahertz radiation by multiphoton resonant excitation of three-level hydrogenlike atoms and homonuclear diatomic molecules or molecular ions with strong laser pulses. The results of analytical and numerical investigations of the problem show that with the proposed mechanism one can achieve the implementation of widely tunable powerful terahertz sources, which may open new perspectives for terahertz science and its applications.

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

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, Michael A.; Lyubinetsky, Igor

    2013-06-12

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-11-01

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

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

    OpenAIRE

    Shigemura Masahiko; Nasuhara Yasuyuki; Konno Satoshi; Shimizu Chikara; Matsuno Kazuhiko; Yamguchi Etsuro; Nishimura Masaharu

    2012-01-01

    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 s...

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

    DEFF Research Database (Denmark)

    Kuznetsov, A.M.; Ulstrup, Jens

    2002-01-01

    reduces to a three-level transition similar to STM of large redox molecules. Recent data for rectification in hexadecyl-quinolinium tricyanodimethanide monolayers by Metzger and co-workers [J. Am. Chem. Soc. 119, 10455 (1997); Acc. Chem. Res. 32, 950 (1999)], are discussed in terms of the reported views......We present a new view and an analytical formalism of electron flow through a donor-acceptor molecule inserted between a pair of metal electrodes. The donor and acceptor levels are strongly coupled to an environmental nuclear continuum. The formalism applies to molecular donor-acceptor systems both...

  13. 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 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)

  14. 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 Earths 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

  15. 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.

  16. 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 350C 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.

  17. 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.

  18. Atmospheric processes on ice nanoparticles in molecular beams

    Science.gov (United States)

    Frnk, Michal; Poterya, Viktoriya

    2014-02-01

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

  19. Atmospheric processes on ice nanoparticles in molecular beams

    Directory of Open Access Journals (Sweden)

    MichalFrnk

    2014-02-01

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

  20. Levels and Atypical Evolutions of the Romanian Demographic Processes

    Directory of Open Access Journals (Sweden)

    Mirela Ionela Aceleanu

    2007-01-01

    Full Text Available Within the XXth century, especially in the second half thereof, the approach views of the relation between the population and economy (both of them regarded in dynamics have multiplied themselves, the points of view as regards this subject becoming not only much more diverse but also opposite. All these views are characterised by the population transformation in endogenous factor (in internal, intrinsic side of the economic development (of the economic growth, factor that, at its turn, is determined by the economic processes. The double position of the population in the demo-economical relations system - as main production factor and as virtual recipient of produced goods - is a strong argument in the favour of the demographic factor as endogenous factor of growth and economic development. The correlations between the two variables are diverse and very difficultly to be quantified. It is known that the effect of the demographic impact upon the economic factor is felt after many years from the date of the demo-economic phenomenon occurring. So, within the last decades, the research intended to identify certain essential, durable relations between the population evolution and the economic growth became more intensive. On this line there are presented atypical evolutions and levels of demographic processes in Romania.

  1. Direct observation of atomic-level nucleation and growth processes from an ultrathin metallic glass films

    Science.gov (United States)

    Huang, K. Q.; Cao, C. R.; Sun, Y. T.; Li, J.; Bai, H. Y.; Gu, L.; Zheng, D. N.; Wang, W. H.

    2016-01-01

    Till date, there have been no direct atomic-level experimental observations of the earliest stages of the nucleation and growth processes of nanocrystals formed by thermally induced crystallization in ultrathin metallic glasses (MGs). Here, we present a study of the crystallization process in atomically thin and highly stable MG films using double spherical aberration-corrected scanning transmission electron microscopy (Cs-TEM). Taking advantage of the stability of MG films with a slow crystallization process and the atomic-level high resolution of Cs-TEM, we observe the formation of the nucleus precursor of nanocrystals formed by atom aggregation followed by concomitant coalescence and stepwise evolution of the shape of the nanocrystals with a monodispersed and separated bimodal size distribution. Molecular dynamics simulation of the atomic motion in the glass film on a rigid amorphous substrate confirms the stepwise evolution processes of atom aggregation, cluster formation, cluster movement on the substrate, and cluster coalescence into larger crystalline particles. Our results might provide a better fundamental understanding of the nucleation and growth processes of nanocrystals in thin MG films.

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

    Science.gov (United States)

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

    2015-06-30

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

  3. Post-processing interstitialcy diffusion from molecular dynamics simulations

    Science.gov (United States)

    Bhardwaj, U.; Bukkuru, S.; Warrier, M.

    2016-01-01

    An algorithm to rigorously trace the interstitialcy diffusion trajectory in crystals is developed. The algorithm incorporates unsupervised learning and graph optimization which obviate the need to input extra domain specific information depending on crystal or temperature of the simulation. The algorithm is implemented in a flexible framework as a post-processor to molecular dynamics (MD) simulations. We describe in detail the reduction of interstitialcy diffusion into known computational problems of unsupervised clustering and graph optimization. We also discuss the steps, computational efficiency and key components of the algorithm. Using the algorithm, thermal interstitialcy diffusion from low to near-melting point temperatures is studied. We encapsulate the algorithms in a modular framework with functionality to calculate diffusion coefficients, migration energies and other trajectory properties. The study validates the algorithm by establishing the conformity of output parameters with experimental values and provides detailed insights for the interstitialcy diffusion mechanism. The algorithm along with the help of supporting visualizations and analysis gives convincing details and a new approach to quantifying diffusion jumps, jump-lengths, time between jumps and to identify interstitials from lattice atoms.

  4. Ellipticity dependence of plateau structures in atomic and molecular processes in a strong laser field

    International Nuclear Information System (INIS)

    In this paper, we present a quantum-mechanical theory in order to describe laser-induced and laser-assisted atomic and molecular processes with an emphasis on an elliptically polarized strong laser field. The features of the high-energy regions of spectra and their cutoffs are analyzed in detail for different values of ellipticity, laser intensities and various atomic and molecular species. Our theoretical study is focused on the ellipticity dependence of the plateau structures that appear in the energy spectra of atomic and molecular processes in strong laser fields. (paper)

  5. The Defense Waste Processing Facility: an innovative process for high-level waste immobilization

    International Nuclear Information System (INIS)

    The Defense Waste Processing Facility (DWPF), under construction at the Department of Energy's Savannah River Plant (SRP), will process defense high-level radioactive waste so that it can be disposed of safely. The DWPF will immobilize the high activity fraction of the waste in borosilicate glass cast in stainless steel canisters which can be handled, stored, transported and disposed of in a geologic repository. The low-activity fraction of the waste, which represents about 90% of the high-level waste HLW volume, will be decontaminated and disposed of on the SRP site. After decontamination the canister will be welded shut by an upset resistance welding technique. In this process a slightly oversized plug is pressed into the canister opening. At the same time a large current is passed through the canister and plug. The higher resistance of the canister/plug interface causes the heat which welds the plug in place. This process provides a high quality, reliable weld by a process easily operated remotely

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

    Energy Technology Data Exchange (ETDEWEB)

    Professor Francisco Zaera

    2007-08-09

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

  7. The molecular basis of low activity levels of coagulation factor VII: a Brazilian cohort.

    Science.gov (United States)

    Rabelo, F Y; Jardim, L L; Landau, M B; Gadelha, T; Corra, M F B; Pereira, I F M; Rezende, S M

    2015-09-01

    Inherited factor VII (FVII) deficiency is the most common among the rare bleeding disorders. It is transmitted as an autosomal recessive inheritance, due to mutations in the FVII gene (F7). Molecular studies of FVII deficiency are rare in non-Caucasian populations. The aim of the study was to evaluate the molecular basis behind low levels of FVII activity (FVII:C) levelsin a cohort of Brazilian patients. A total of 34 patients with low FVII levels were clinically evaluated and submitted to laboratory tests, among these, prothrombin time and FVII:C, with different thromboplastins. All exons and intron/exon boundaries of F7 were amplified and sequenced. A total of 14 genetic alterations were identified, of which six were described previously, c.1091G>A, c.1151C>T, c.-323_-313insCCTATATCCT, c.285G>A, c.525C>T, c.1238G>A and eight (54.0%) and eight were new, c.128G>A, c.252C>T, c.348G>A, c.417G>A, c.426G>A, c.745_747delGTG, c.843G>A and c.805+52C>T. In addition to the mutation c.1091G>A, known as FVII Padua, the mutation c.1151C>T also presented discrepant FVII:C levels when tested with human and rabbit brain thromboplastin. There was no association between phenotype and genotype. Most of the identified genetic alterations found were polymorphisms. Low levels of FVII:C in this population were mostly related to polymorphisms in F7 and associated with a mild clinical phenotype. Mutation c.1151C>T was associated with discrepant levels of FVII:C using different thromboplastins, such as reported with FVII Padua. PMID:25828579

  8. Molecular Surveillance of Viral Processes Using Silicon Nitride Membranes

    OpenAIRE

    Kelly, Deborah F; McDonald, Sarah M.; Madeline J. Dukes; Allison O. McKell; Boudreaux, Crystal E; Tanner, Justin R.; Brian L. Gilmore

    2013-01-01

    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 la...

  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. 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.

  11. Coarse-grained Molecular-level Analysis of Polyurea Properties and Shock-mitigation Potential

    Science.gov (United States)

    Grujicic, M.; Snipes, J. S.; Ramaswami, S.; Yavari, R.; Runt, J.; Tarter, J.; Dillon, G.

    2013-07-01

    Several experimental investigations reported in the open literature clearly established that polyurea (PU), an elastic copolymer, has an unusually high ability to attenuate and disperse shock waves. This behavior of PU is normally attributed to its unique nanometer-scale two-phase microstructure consisting of (high glass-transition temperature, T g) hydrogen-bonded discrete, hard domains dispersed within a (low T g) contiguous soft matrix. However, details regarding the mechanism(s) responsible for the superior shock-wave mitigation capacity of PU are still elusive. In the present study, molecular-level computational methods and tools are used to help us identify and characterize these mechanism(s). Because the shock-wave front structure and propagation involve coordinated motion of a large number of atoms and nano-second to micro-second characteristic times, these phenomena cannot be readily analyzed using all-atom molecular-level modeling and simulation techniques. To overcome this problem, all-atom PU microstructure is coarse-grained by introducing larger particles (beads), which account for the collective degrees of freedom of the constituent atoms, the associated force-field functions determined and parameterized using all-atom computational results, and the resulting coarse-grained model analyzed using conventional molecular-level computational methods and tools. The results thus obtained revealed that a combination of different deformation mechanisms (primarily shock-induced ordering and crystallization of hard domains and coordinated shuffle-like lateral motion of the soft-matrix segments) is most likely responsible for the superior ability of PU to attenuate/disperse shock waves.

  12. 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 GESCDisposal 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 nu

  13. Lovastatin production: From molecular basis to industrial process optimization.

    Science.gov (United States)

    Mulder, Kelly C L; Mulinari, Flvia; Franco, Octvio L; Soares, Maria S F; Magalhes, Beatriz S; Parachin, Ndia S

    2015-11-01

    Lovastatin, composed of secondary metabolites produced by filamentous fungi, is the most frequently used drug for hypercholesterolemia treatment due to the fact that lovastatin is a competitive inhibitor of HMG-CoA reductase. Moreover, recent studies have shown several important applications for lovastatin including antimicrobial agents and treatments for cancers and bone diseases. Studies regarding the lovastatin biosynthetic pathway have also demonstrated that lovastatin is synthesized from two-chain reactions using acetate and malonyl-CoA as a substrate. It is also known that there are two key enzymes involved in the biosynthetic pathway called polyketide synthases (PKS). Those are characterized as multifunctional enzymes and are encoded by specific genes organized in clusters on the fungal genome. Since it is a secondary metabolite, cultivation process optimization for lovastatin biosynthesis has included nitrogen limitation and non-fermentable carbon sources such as lactose and glycerol. Additionally, the influences of temperature, pH, agitation/aeration, and particle and inoculum size on lovastatin production have been also described. Although many reviews have been published covering different aspects of lovastatin production, this review brings, for the first time, complete information about the genetic basis for lovastatin production, detection and quantification, strain screening and cultivation process optimization. Moreover, this review covers all the information available from patent databases covering each protected aspect during lovastatin bio-production. PMID:25868803

  14. 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.

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

    International Nuclear Information System (INIS)

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

  16. Unravelling Protein-DNA Interactions at Molecular Level: A DFT and NCI Study.

    Science.gov (United States)

    Gonzlez, J; Baos, I; Len, I; Contreras-Garca, J; Cocinero, E J; Lesarri, A; Fernndez, J A; Milln, J

    2016-02-01

    Histone-DNA interactions were probed computationally at a molecular level, by characterizing the bimolecular clusters constituted by selected amino acid derivatives with polar (asparagine and glutamine), nonpolar (alanine, valine, and isoleucine), and charged (arginine) side chains and methylated pyrimidinic (1-methylcytosine and 1-methylthymine) and puric (9-methyladenine and 9-methylguanine) DNA bases. The computational approach combined different methodologies: a molecular mechanics (MMFFs forced field) conformational search and structural and vibrational density-functional calculations (M06-2X with double and triple-? Pople's basis sets). To dissect the interactions, intermolecular forces were analyzed with the Non-Covalent Interactions (NCI) analysis. The results for the 24 different clusters studied show a noticeable correlation between the calculated binding energies and the propensities for protein-DNA base interactions found in the literature. Such correlation holded even for the interaction of the selected amino acid derivatives with Watson and Crick pairs. Therefore, the balance between hydrogen bonds and van der Waals interactions (specially stacking) in the control of the final shape of the investigated amino acid-DNA base pairs seems to be well reproduced in dispersion-corrected DFT molecular models, reinforcing the idea that the specificity between the amino acids and the DNA bases play an important role in the regulation of DNA. PMID:26765058

  17. First-principle simulations of molecular processes at semiconductor surfaces

    International Nuclear Information System (INIS)

    The authors present an overview of basic adsorption and dynamical processes at semiconductor surfaces, studied by first-principle simulations. They have considered prototypical semiconductor surfaces such as GaAs(110), which is the cleavage plane of GaAs, and Si(100), which is the most common orientation for silicon from epitaxial growth. The authors present an adsorption path and the stable configurations of a Cl2 molecule on GaAs(110), as well as the equilibrium state for complete and partial monolayer adsorption of H on the same surface. They also show the dynamical evolution of Si2 dimers on the Si(100) face: they alternate their buckling in a correlated way producing different reconstructions

  18. Understanding the role of London dispersion forces in molecular surface processes

    Science.gov (United States)

    Cooper, Valentino R.

    2012-02-01

    The interactions and dynamics of molecules at surfaces and within pores are essential to many chemical processes, ranging from molecular storage to catalysis and self-assembly. A molecular level understanding of molecule-surface interactions is crucial for tuning surface/pore selectivity and reactivity. While it is clear that strong chemisorption bonds facilitate these interactions, the role of weaker van der Waals (vdW) forces, which include London dispersion and ?-? stacking interactions, are often unknown or overlooked. Recent advances in density functional theory (DFT) have now made it possible to reliably account for London dispersion interactions. In this paper, I will discuss the use of one such technique, the Rutgers-Chalmers vdW non-local correlation functional,ootnotetextM. Dion, H. Rydberg, E. Schr"oder, B. I. Lundqvist and D. C. Langreth, Phys. Rev. Lett., 92, 246401 (2004)^,ootnotetextT. Thonhauser, V. R. Cooper, S. Li, A. Puzder, P. Hyldgaard, and David C. Langreth, Phys. Rev. B, 76, 125112 (2007) to demonstrate how the inclusion of London dispersion forces is critical for a truly first principles understanding of processes sensitive to molecule-surface interactions, such as the loading of H2 within porous materials and the chemisorption of organic molecules at surfaces. These works highlight the fundamental importance of London dispersion interactions in the broader context of chemical physics. This work was supported by the Department of Energy, BES, Materials Sciences and Engineering Division.ootnotetextCollaborators: Guo Li, Isaac Tamblyn, Yungok Ihm, Jun-Hyung Cho, Shixuan Du, Jeffrey B. Neaton, Hong-Jun Gao, Zhenyu Zhang, James R. Morris

  19. Proton NMR for Measuring Quantum Level Crossing in the Magnetic Molecular Ring Fe10

    International Nuclear Information System (INIS)

    The proton nuclear spin-lattice relaxation rate 1/T1 has been measured as a function of temperature and magnetic field (up to 15thinspthinspT) in the molecular magnetic ring Fe10( OCH3)20(O2CCH2 Cl)10 (Fe10). Striking enhancement of 1/T1 is observed around magnetic field values corresponding to a crossing between the ground state and the excited states of the molecule. We propose that this is due to a cross-relaxation effect between the nuclear Zeeman reservoir and the reservoir of the Zeeman levels of the molecule. This effect provides a powerful tool to investigate quantum dynamical phenomena at level crossing. copyright 1999 The American Physical Society

  20. Proton NMR for Measuring Quantum Level Crossing in the Magnetic Molecular Ring Fe10

    Energy Technology Data Exchange (ETDEWEB)

    Julien, M.; Jang, Z.H.; Borsa, F. [Department of Physics and Astronomy, Ames Laboratory, Iowa State University, Ames, Iowa 50011 (United States); Julien, M.; Lascialfari, A.; Borsa, F. [Dipartimento di Fisica A. Volta e Unita INFM di Pavia, Via Bassi 6, 27100 Pavia (Italy); Horvatic, M. [Grenoble High Magnetic Field Laboratory, CNRS and MPI-FKF, BP 166, 38042 Grenoble Cedex 9 (France); Caneschi, A.; Gatteschi, D. [Department of Chemistry, University of Firenze, Via Maragliano 77, 50144 Firenze (Italy)

    1999-07-01

    The proton nuclear spin-lattice relaxation rate 1/T{sub 1} has been measured as a function of temperature and magnetic field (up to 15thinspthinspT) in the molecular magnetic ring Fe{sub 10}( OCH{sub 3}){sub 20}(O{sub 2}CCH{sub 2} Cl){sub 10} (Fe10). Striking enhancement of 1/T{sub 1} is observed around magnetic field values corresponding to a crossing between the ground state and the excited states of the molecule. We propose that this is due to a cross-relaxation effect between the nuclear Zeeman reservoir and the reservoir of the Zeeman levels of the molecule. This effect provides a powerful tool to investigate quantum dynamical phenomena at level crossing. {copyright} {ital 1999} {ital The American Physical Society}

  1. Efficient inverted polymer solar cells with thermal-evaporated and solution-processed small molecular electron extraction layer

    Science.gov (United States)

    Sun, Fu-Zhou; Shi, Ai-Li; Xu, Zai-Quan; Wei, Huai-Xin; Li, Yan-Qing; Lee, Shuit-Tong; Tang, Jian-Xin

    2013-04-01

    Efficient inverted polymer solar cell is reported upon by integrating with a small molecular 1,3,5-tri(phenyl-2-benzimi-dazolyl)-benzene (TPBi) electron extraction layer (EEL) at low processing temperature with thermal-evaporation and solution-process, resulting in the power conversion efficiencies of 3.70% and 3.47%, respectively. The potential of TPBi as an efficient EEL is associated with its suitable electronic energy level for electron extraction and hole blocking from the active layer to the indium tin oxide cathode.

  2. Mean level signal crossing rate for an arbitrary stochastic process

    DEFF Research Database (Denmark)

    Yura, Harold T.; Hanson, Steen Grner

    2010-01-01

    The issue of the mean signal level crossing rate for various probability density functions with primary relevance for optics is discussed based on a new analytical method. This method relies on a unique transformation that transforms the probability distribution under investigation into a normal probability distribution, for which the distribution of mean level crossings is known. In general, the analytical results for the mean level crossing rate are supported and confirmed by numerical simulat...

  3. 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...

  4. Ions colliding with molecules and molecular clusters : fragmentation and growth processes

    OpenAIRE

    Chen, Tao

    2015-01-01

    Inthis work we will discuss fragmentation and molecular growth processes in collisions of Polycyclic Aromatic Hydrocarbon (PAH) molecules, fullerenes, or their clusters with atoms or atomic ions. Simple collision models as well as molecular structure calculations are used to aid the interpretations of the present and other experimental results. Fragmentation features at center-of-mass collision energies around 10 keV are dominated by interactions between the fast ion/atom and the electron cl...

  5. Supramolecular and heterosupramolecar chemistry in controlled release and molecular recognition processes

    OpenAIRE

    Agostini, Alessandro

    2013-01-01

    La presente tesis doctoral titulada Supramolecular and heterosupramolecular chemistry in controlled release and molecular recognition processes est centrada en los dos aspectos principales de la qumica supramolecular que han experimentado un gran auge en los ltimos aos: el reconocimiento molecular y los procesos de liberacin controlada. En particular la primera parte de la tesis se focaliza en el diseo y sntesis de molculas orgnicas que pueden ser empleados cmo...

  6. 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...

  7. Information processing in parallel through directionally resolved molecular polarization components in coherent multidimensional spectroscopy.

    Science.gov (United States)

    Yan, Tian-Min; Fresch, Barbara; Levine, R D; Remacle, F

    2015-08-14

    We propose that information processing can be implemented by measuring the directional components of the macroscopic polarization of an ensemble of molecules subject to a sequence of laser pulses. We describe the logic operation theoretically and demonstrate it by simulations. The measurement of integrated stimulated emission in different phase matching spatial directions provides a logic decomposition of a function that is the discrete analog of an integral transform. The logic operation is reversible and all the possible outputs are computed in parallel for all sets of possible multivalued inputs. The number of logic variables of the function is the number of laser pulses used in sequence. The logic function that is computed depends on the chosen chromophoric molecular complex and on its interactions with the solvent and on the two time intervals between the three pulses and the pulse strengths and polarizations. The outputs are the homodyne detected values of the polarization components that are measured in the allowed phase matching macroscopic directions, kl, kl=?iliki where ki is the propagation direction of the ith pulse and {li} is a set of integers that encodes the multivalued inputs. Parallelism is inherently implemented because all the partial polarizations that define the outputs are processed simultaneously. The outputs, which are read directly on the macroscopic level, can be multivalued because the high dynamical range of partial polarization measurements by nonlinear coherent spectroscopy allows for fine binning of the signals. The outputs are uniquely related to the inputs so that the logic is reversible. PMID:26277126

  8. 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 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)

  9. 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...

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2005-01-01

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

  12. 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

  13. 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

  14. 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 ...

  15. New alternatives for processing low and medium level liquid wastes

    International Nuclear Information System (INIS)

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

  16. 77 FR 47337 - Project-Level Predecisional Administrative Review Process

    Science.gov (United States)

    2012-08-08

    ...communications technology, including email, web pages, and social media. The Department believes that within these tools is the...government and the States, or on the distribution of power and responsibilities among the various levels of...

  17. Interplay of formulation and process methodology on the extent of nifedipine molecular dispersion in polymers.

    Science.gov (United States)

    Huang, Jingjun; Li, Ying; Wigent, Rodney J; Malick, Waseem A; Sandhu, Harpreet K; Singhal, Dharmendra; Shah, Navnit H

    2011-11-25

    The aim of this study is to evaluate effects of formulation and process technology on drug molecular dispersibility in solid dispersions (SDs). Nifedipine solid dispersions with ethylcellulose (EC) and/or Eudragit RL (RL) prepared by co-precipitation, co-evaporation, and fusion methods were characterized with FTIR, DSC, and XRPD for the content of nifedipine as molecular dispersion, amorphous and/or crystalline suspensions. A method was developed based on regular solution and Flory-Huggins theories to calculate drug-polymer interaction parameter in solid dispersion systems. A synergic effect of RL and EC on nifedipine molecular dispersibility in solid dispersions was observed. Increasing RL/EC ratio resulted in a higher degree of drug-polymer interaction that thermodynamically favored molecular dispersion, which, however, was counteracted by a corresponding decrease in the matrix glass transition point that kinetically favored phase-separation. Process methodology was found to play an important role in the formation of amorphous SD. The ranking of technologies with respect to the extent of molecular dispersion from high to low is fusion>co-evaporation>co-precipitation, wherein the solidification rate of polymeric solution and non-solvent effects were linked to kinetic entrapment of drug molecules in polymeric networks. Since nifedipine molecular dispersibility in EC/RL polymer(s) is a result of interplay between thermodynamic and kinetic factors, nifedipine molecular dispersions prepared for this study are thermodynamically metastable systems. To explore those supersaturation systems for use in drug delivery of poorly water soluble drugs, it is critical to balance drug-polymer interactions and matrix glass transition point and to consider a process technology with a fast solidification rate during formulation and process development of amorphous SD. PMID:21871546

  18. 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.

  19. 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

  20. 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 are primarily responsible for short-term toxicity of Ag-NPs to Eisenia fetida.

  1. Determination of chloride at picogram levels by molecular fluorescence in a graphite furnace.

    Science.gov (United States)

    Anwar, J; Anzano, J M; Petrucci, G; Winefordner, J D

    1991-10-01

    Chloride was determined at nanogram levels by adding excess of indium to the sample introduced into a graphite furnace and measuring the laser induced molecular fluorescence of indium chloride. The diatomic molecules of indium chloride were excited by a pulsed dye laser at 267 nm and fluorescence was measured at 359 nm. The effects of various parameters including amount of indium added, furnace thermal conditions and presence of concomitants were also studied. A linear calibration in the range of 0.025-1.25 ng and a detection limit of 17 pg of chloride were obtained under optimum conditions. The analytical usefulness of the method was checked by determining the chloride content in National Institute of Standards and Technology, Standard Reference Materials 1571a and 1571b Orchard Leaves. PMID:1801600

  2. Acid-Base Interactions at the Molecular Level: Adhesion and Friction Studies with Interfacial Force Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Burns, A.R.; Carpick, R.W.; Houston, J.E.; Michalske, T.A.

    1998-12-09

    To examine the forces of acid-base adhesive interactions at the molecular level, we utilize the scanning probe Interracial Force Microscope (IFM). Unlike cantilever-based atomic force microscopes, the EM is a non-compliant, mechanically stable probe that provides a complete adhesive profile without jump-to-contact. In this way, we are able to quantitatively measure the work of adhesion and bond energies at well-defined, nanometer-scale single asperity contacts. In particular, we will discuss the displacement-controlled adhesive forces between self-assembled monolayer of functionalized alkanethiols strongly bound to a gold substrate and a similarly functionalized tip. We also discuss a method utilizing decoupled lateral and normal force sensors to simultaneously observe the onset of both friction and chemical bond formation. Measurements show that friction can be directly attributed to bond formation and rupture well before repulsive contact.

  3. 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

  4. Spectrally selective molecular doped solids: spectroscopy, photophysics and their application to ultrafast optical pulse processing

    International Nuclear Information System (INIS)

    The persistent spectral hole-burning (PSHB) phenomenon observed in molecular doped polymers cooled down to liquid helium temperatures allows the engraving of spectral structures in the inhomogeneous absorption profile of the material. This phenomenon known since 1974 has became a fruitful field for the study of the intimacy of complex molecular systems in the solid state, revealing high-resolution spectroscopy, photophysics, photochemistry and dynamics of molecular doped amorphous media, organic as well as inorganic. A PSHB molecular doped solid can be programmed in spectral domain and therefore, it can be converted in an optical processor capable to achieve user-defined optical functions. Some aspects of this field are illustrated in the present paper. An application is presented where a naphthalocyanine doped polymer film is used in a demonstrative experiment to prove that temporal aberration free re-compression of ultra-short light pulses is feasible. Perspectives for the coherent control of light fields or photochemical processes are also evoked

  5. Spectrally selective molecular doped solids: spectroscopy, photophysics and their application to ultrafast optical pulse processing

    Energy Technology Data Exchange (ETDEWEB)

    Galaup, Jean-Pierre [Laboratoire Aime Cotton, CNRS UPR 3321, Ba-hat t. 505, 91405 Orsay cedex (France)]. E-mail: jean-pierre.galaup@lac.u-psud.fr

    2005-04-15

    The persistent spectral hole-burning (PSHB) phenomenon observed in molecular doped polymers cooled down to liquid helium temperatures allows the engraving of spectral structures in the inhomogeneous absorption profile of the material. This phenomenon known since 1974 has became a fruitful field for the study of the intimacy of complex molecular systems in the solid state, revealing high-resolution spectroscopy, photophysics, photochemistry and dynamics of molecular doped amorphous media, organic as well as inorganic. A PSHB molecular doped solid can be programmed in spectral domain and therefore, it can be converted in an optical processor capable to achieve user-defined optical functions. Some aspects of this field are illustrated in the present paper. An application is presented where a naphthalocyanine doped polymer film is used in a demonstrative experiment to prove that temporal aberration free re-compression of ultra-short light pulses is feasible. Perspectives for the coherent control of light fields or photochemical processes are also evoked.

  6. 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.

  7. Yakima tribal perspectives on high level selection process

    International Nuclear Information System (INIS)

    When Congress went through the arduous process of fashioning a comprehensive plan for resolution of the nation's long-standing nuclear waste problem, it explicitly recognized that past federal efforts in this area had been inadequate. Congress also recognized that the primary reasons for the failure of earlier federal efforts was failure on the part of the federal government to seriously deal with very real technical questions about the geologic adequacy of prospective repository sites, and failure to address the concerns of state, tribal, and local governments in the repository selection and development process

  8. Investigating Students' Ability to Transfer Ideas Learned from Molecular Animations of the Dissolution Process

    Science.gov (United States)

    Kelly, Resa M.; Jones, Loretta L.

    2008-01-01

    Animations of the particulate level of matter are widely available for use in chemistry classes and are often the primary means of representing molecular behavior. These animations may also be viewed by individual students using textbook Web sites, although without reinforcement or feedback. It is not known to what extent the material in these

  9. Ultraviolet-excited High Rotational Level Molecular Hydrogen in Interstellar Clouds: Models and Observational Results

    Science.gov (United States)

    Lee, Dae-Hee; Pak, Soojong; van Dishoeck, Ewine F.

    We have calculated 2448 interstellar cloud models to investigate the formation and destruction of high rotational level H2 according to the combinations of five physical conditions: the input UV intensity, the H2 column density, cloud temperature, total density, and the H2 formation rate efficiency. The models include the populations of all the accessible states of H2 with the rotational quantum number J Dishoeck 1987). The high rotational levels J = 4 and J = 5 are both populated by direct formation into these levels of newly created molecules, and by pumping from J = 0 and J = 1, respectively. The model results show that N(4)/N(0) and N(5)/N(1) are proportional to the incident UV intensity, as predicted by Jura (1975), and are linearly decreased with the logarithm of molecular fraction, log f. Also, recent observational results are discussed with reference to the calculated models. Twenty-four high resolution spectra of H2 in the LMC and SMC (Tumlinson et al. 2002), and three translucent clouds (Sonnentrucker et al. 2002; Sonnentrucker et al. 2003; Rachford et al. 2001), observed by FUSE, provide an appropriate data set to examine the models. We have surveyed 54 early-type stars in the Galactic disk and halo with the Berkeley Extreme and Far-Ultraviolet Spectrometer (BEFS), part of the ORFEUS telescope, to obtain interstellar H2 absorption spectra for this research. The observed high rotational H2 level line ratios are well followed in the models, so that we can estimate the densities of the clouds from the models.

  10. Interference asymmetry of molecular frame photoelectron angular istributions in bichromatic UV ionization processes

    Science.gov (United States)

    Yuan, Kai-Jun; Bandrauk, André D.

    2016-03-01

    We investigate molecular photoionization by ultrafast bichromatic linearly polarized UV laser pulses at frequencies 2{ω }1={ω }2 perpendicular to the internuclear axis R involving π orbital excitation. Results from numerical solutions of time dependent Schrödinger equations for aligned {{{H}}}2+ show that molecular frame photoelectron angular distributions (MFPADs) exhibit signatures of asymmetry perpendicular to the molecular symmetry axis, arising from interference of coherent electron wave packets created by respectively one {ω }2 and two-photon 2{ω }1 absorption. A resonant excitation process between the ground 1s{σ }{{g}} state and the excited 2p{π }{{u}} state is triggered by the {ω }1 pulse. The asymmetry of MFPADs varies periodically with pulse intensity I 0 and duration T, which we attribute to coherent resonant Rabi oscillations in electronic state population. A perturbative model is adopted to qualitatively describe and analyze these effects in both resonant and nonresonant photoionization processes.

  11. 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.

  12. 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.

  13. 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).

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-10-15

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

  16. 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.

  17. 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

  18. Technetium removal processes for soluble defense high-level waste

    International Nuclear Information System (INIS)

    Two methods for removing technetium from soluble defense high-level waste are described. In the first method, technetium is precipitated as tetraphenylphosphonium pertechnetate and separated from the decontaminated solution using sintered metal crossflow filters. In the second method, pertechnetate is removed from solution using a strong base anion exchange resin and then eluted from the resin with nitric acid. The nitric acid is recovered by sorption of the pertechnetate on a weak base ion exchange resin. The pertechnetate is eluted from the weak base resin with NaOH and recovered by precipitation as the sulfide or oxide. 7 refs., 3 figs

  19. Vitrification processing method and device for high level liquid waste

    International Nuclear Information System (INIS)

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

  20. 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)

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

    OpenAIRE

    Wispelaere, Irene Martine de

    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 ...

  2. The LHCb Data Acquisition and High Level Trigger Processing Architecture

    Science.gov (United States)

    Frank, M.; Gaspar, C.; Jost, B.; Neufeld, N.

    2015-12-01

    The LHCb experiment at the LHC accelerator at CERN collects collisions of particle bunches at 40 MHz. After a first level of hardware trigger with an output rate of 1 MHz, the physically interesting collisions are selected by running dedicated trigger algorithms in the High Level Trigger (HLT) computing farm. This farm consists of up to roughly 25000 CPU cores in roughly 1750 physical nodes each equipped with up to 4 TB local storage space. This work describes the LHCb online system with an emphasis on the developments implemented during the current long shutdown (LS1). We will elaborate the architecture to treble the available CPU power of the HLT farm and the technicalities to determine and verify precise calibration and alignment constants which are fed to the HLT event selection procedure. We will describe how the constants are fed into a two stage HLT event selection facility using extensively the local disk buffering capabilities on the worker nodes. With the installed disk buffers, the CPU resources can be used during periods of up to ten days without beams. These periods in the past accounted to more than 70% of the total time.

  3. The LHCb Data Acquisition and High Level Trigger Processing Architecture

    CERN Document Server

    Frank, M; Jost, B; Neufeld, N

    2015-01-01

    The LHCb experiment at the LHC accelerator at CERN collects collisions of particle bunches at 40 MHz. After a first level of hardware trigger with an output rate of 1 MHz, the physically interesting collisions are selected by running dedicated trigger algorithms in the High Level Trigger (HLT) computing farm. This farm consists of up to roughly 25000 CPU cores in roughly 1750 physical nodes each equipped with up to 4 TB local storage space. This work describes the LHCb online system with an emphasis on the developments implemented during the current long shutdown (LS1). We will elaborate the architecture to treble the available CPU power of the HLT farm and the technicalities to determine and verify precise calibration and alignment constants which are fed to the HLT event selection procedure. We will describe how the constants are fed into a two stage HLT event selection facility using extensively the local disk buffering capabilities on the worker nodes. With the installed disk buffers, the CPU resources ca...

  4. Unraveling liver complexity from molecular to organ level: challenges and perspectives.

    Science.gov (United States)

    D'Alessandro, L A; Hoehme, S; Henney, A; Drasdo, D; Klingmller, U

    2015-01-01

    Biological responses are determined by information processing at multiple and highly interconnected scales. Within a tissue the individual cells respond to extracellular stimuli by regulating intracellular signaling pathways that in turn determine cell fate decisions and influence the behavior of neighboring cells. As a consequence the cellular responses critically impact tissue composition and architecture. Understanding the regulation of these mechanisms at different scales is key to unravel the emergent properties of biological systems. In this perspective, a multidisciplinary approach combining experimental data with mathematical modeling is introduced. We report the approach applied within the Virtual Liver Network to analyze processes that regulate liver functions from single cell responses to the organ level using a number of examples. By facilitating interdisciplinary collaborations, the Virtual Liver Network studies liver regeneration and inflammatory processes as well as liver metabolic functions at multiple scales, and thus provides a suitable example to identify challenges and point out potential future application of multi-scale systems biology. PMID:25433231

  5. A simplified molecular method for distinguishing among species and ploidy levels in European water frogs (Pelophylax).

    Science.gov (United States)

    Hauswaldt, J Susanne; Her, Manuela; Ogielska, Maria; Christiansen, Ditte G; Dziewulska-Szwajkowska, Daria; Czernicka, El?bieta; Vences, Miguel

    2012-09-01

    Western Palearctic water frogs in the genus Pelophylax are a set of morphologically similar anuran species that form hybridogenetic complexes. Fully reliable identification of species and especially of hybrid ploidy depends on karyological and molecular methods. In central Europe, native water frog populations consist of the Pelophylax esculentus complex, that is, P.lessonae (LL), P.ridibundus (RR) and the hybrid form P.esculentus that can have different karyotypes (RL, LLR and RRL). We developed existing molecular methods further and propose a simple PCR method based on size-differences in the length of the serum albumin intron-1 and the RanaCR1, a non-LTR retrotransposon of the chicken repeat (CR) family. This PCR yields taxon-specific banding patterns that can easily be screened by standard agarose gel electrophoresis and correctly identify species in all of the 160 samples that had been identified to karyotype with other methods. To distinguish ploidy levels in LR, LLR and RRL specimens, we used the ratio of the peak heights of the larger (ridibundus specific) to the smaller (lessonae specific) bands of fluorescently labelled PCR products resolved on a capillary DNA sequencer and obtained a correct assignment of the karyotype in 93% of cases. Our new method will cut down time and expenses drastically for a reliable identification of water frogs of the P.esculentus complex and potentially for identification of other hybridogenetic complexes and/or taxa, and it even serves as a good indicator of the ploidy status of hybrid individuals. PMID:22716763

  6. [Implementation on the operating level of the nursing process].

    Science.gov (United States)

    Villalobos, N A

    1999-01-01

    The development of the nursing care attention process guided through the PDCA. (plan, do, check, act), provides a continuous improvement of our actual context. The meaning of PDCA is translated as VIDA for: view, implementation, discernment, at just. For its application it takes in view the change theory of Kurt Lewin. This paper provides the results of the Implementation stage using different approaches as technical care, education, administration and research. These strategies show that people did not express their feelings, beliefs and their own expectations and autonomy in nursing care. They even do not develop their citizenship, right of living and being able to grow. PMID:10734939

  7. Exposure to low pH induces molecular level changes in the marine worm, Platynereis dumerilii.

    Science.gov (United States)

    Wäge, Janine; Lerebours, Adelaide; Hardege, Jörg D; Rotchell, Jeanette M

    2016-02-01

    Fossil fuel emissions and changes in net land use lead to an increase in atmospheric CO2 concentration and a subsequent decrease of ocean pH. Noticeable effects on organisms' calcification rate, shell structure and energy metabolism have been reported in the literature. To date, little is known about the molecular mechanisms altered under low pH exposure, especially in non-calcifying organisms. We used a suppression subtractive hybridisation (SSH) approach to characterise differentially expressed genes isolated from Platynereis dumerilii, a non-calcifying marine polychaeta species, kept at normal and low pH conditions. Several gene sequences have been identified as differentially regulated. These are involved in processes previously considered as indicators of environment change, such as energy metabolism (NADH dehydrogenase, 2-oxoglutarate dehydrogenase, cytochrome c oxidase and ATP synthase subunit F), while others are involved in cytoskeleton function (paramyosin and calponin) and immune defence (fucolectin-1 and paneth cell-specific alpha-defensin) processes. This is the first study of differential gene expression in a non-calcifying, marine polychaete exposed to low pH seawater conditions and suggests that mechanisms of impact may include additional pathways not previously identified as impacted by low pH in other species. PMID:26476878

  8. Atomic-level stress and induced growth of wurtzite zinc oxide using molecular dynamics simulation

    International Nuclear Information System (INIS)

    Molecular dynamics is used to simulate the film growth process of zinc oxide (ZnO) deposited on a ZnO substrate. In the work, the Buckingham-type interatomic potential is modelled to describe the interaction of Zn-O atoms. The effects of incident energy and substrate temperature on the layer coverage function, radial distribution function and residual stress are investigated. Results show that the crystal growth of the deposition film is a symmetric wurtzite lattice along the [0?0?0?1] direction due to charge transformation. Epitaxial-like growth only occurs at very low incident energies, while the intermixing process could start from an incident energy of 3 eV. The average stress of the Zn layer is a compressive stress that is close to zero. However, the average mean biaxial stress and the normal stress of the O layer are -4.49 GPa and -3.07 GPa, respectively. The simulation results are compared with experimental results available in the literature. (paper)

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

    Science.gov (United States)

    Erdmann, Thorsten; Albert, Philipp J.; Schwarz, Ulrich S.

    2013-11-01

    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 the fraction of bound motors under load and thus to firm attachment even for small ensembles. This adaptation to load results in a concave force-velocity relation described by a Hill relation. For external load provided by a linear spring, myosin II ensembles dynamically adjust themselves towards an isometric state with constant average position and load. The dynamics of the ensembles is now determined mainly by the distribution of motors over the different kinds of bound states. For increasing stiffness of the external spring, there is a sharp transition beyond which myosin II can no longer perform the power stroke. Slow unbinding from the pre-power-stroke state protects the ensembles against detachment.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-11-07

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

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

    International Nuclear Information System (INIS)

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

  12. MIPAS Level 1B algorithms overview: operational processing and characterization

    Directory of Open Access Journals (Sweden)

    A. Kleinert

    2007-01-01

    Full Text Available This paper gives an overview of the MIPAS Level 1B (L1B processor whose main objective is to calibrate atmospheric measurements radiometrically, spectrally and geo-located. It presents also the results of instrument characterization done on ground and during the first years in-flight. An accurate calibration is mandatory for high quality atmospheric retrievals. MIPAS has shown very good performance and stability. The noise equivalent spectral radiance ranges from 3 to 50 nW/(cm2 sr cm?1 and is well within the requirements over nearly the whole spetral range. The systematic radiometric error is estimated to be within 1 or 2% in most situations.

  13. 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

  14. Processing highly tritiated water desorbed from molecular sieve bed using PERMCAT

    International Nuclear Information System (INIS)

    Highlights: ? HTW processed with PERMCAT. ? Processing of highly tritiated water (HTW). ? Molecular sieve bed with HTW adsorbed. - Abstract: Tritium handling facilities use molecular sieve beds (MSB) to collect and recover tritiated water. After reaching the capacity limit of the MSB, the water is desorbed and decontaminated in a water detritiation system (WDS). In the case of highly tritiated water (HTW) absorbed into a MSB, an inherent safe option for processing is necessary due to the HTW specific properties. Ideally, HTW should be processed immediately in a continuous mode. With this in consideration, the water desorption process from a zeolite bed was developed and optimized in a dedicated non active facility. The results of this experiments were applied into the regeneration of a MSB previously loaded with HTW containing an activity of 1.9 1014 Bq kg?1. The water was desorbed, by step increasing the temperature bed and fed by helium carrier gas into the PERMCAT for detritiation and tritium recovery. The processed water was collected in a dry MSB downstream of the PERMCAT. These initial studies successfully demonstrate the viability of the process. The obtained results of the preliminary study and the subsequent tests with tritium, will provide useful information for the design of tritium processes relying on MSB, such as the water processing foreseen for the test blanket modules in ITER.

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

    OpenAIRE

    RonaldHbner

    2011-01-01

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

  16. 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

  17. 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)

  18. Biomechanical and biophysical environment of bone from the macroscopic to the pericellular and molecular level.

    Science.gov (United States)

    Ren, Li; Yang, Pengfei; Wang, Zhe; Zhang, Jian; Ding, Chong; Shang, Peng

    2015-10-01

    Bones with complicated hierarchical configuration and microstructures constitute the load-bearing system. Mechanical loading plays an essential role in maintaining bone health and regulating bone mechanical adaptation (modeling and remodeling). The whole-bone or sub-region (macroscopic) mechanical signals, including locomotion-induced loading and external actuator-generated vibration, ultrasound, oscillatory skeletal muscle stimulation, etc., give rise to sophisticated and distinct biomechanical and biophysical environments at the pericellular (microscopic) and collagen/mineral molecular (nanoscopic) levels, which are the direct stimulations that positively influence bone adaptation. While under microgravity, the stimulations decrease or even disappear, which exerts a negative influence on bone adaptation. A full understanding of the biomechanical and biophysical environment at different levels is necessary for exploring bone biomechanical properties and mechanical adaptation. In this review, the mechanical transferring theories from the macroscopic to the microscopic and nanoscopic levels are elucidated. First, detailed information of the hierarchical structures and biochemical composition of bone, which are the foundations for mechanical signal propagation, are presented. Second, the deformation feature of load-bearing bone during locomotion is clarified as a combination of bending and torsion rather than simplex bending. The bone matrix strains at microscopic and nanoscopic levels directly induced by bone deformation are critically discussed, and the strain concentration mechanism due to the complicated microstructures is highlighted. Third, the biomechanical and biophysical environments at microscopic and nanoscopic levels positively generated during bone matrix deformation or by dynamic mechanical loadings induced by external actuators, as well as those negatively affected under microgravity, are systematically discussed, including the interstitial fluid flow (IFF) within the lacunar-canalicular system and at the endosteum, the piezoelectricity at the deformed bone surface, and the streaming potential accompanying the IFF. Their generation mechanisms and the regulation effect on bone adaptation are presented. The IFF-induced chemotransport effect, shear stress, and fluid drag on the pericellular matrix are meaningful and noteworthy. Furthermore, we firmly believe that bone adaptation is regulated by the combination of bone biomechanical and biophysical environment, not only the commonly considered matrix strain, fluid shear stress, and hydrostatic pressure, but also the piezoelectricity and streaming potential. Especially, it is necessary to incorporate bone matrix piezoelectricity and streaming potential to explain how osteoblasts (bone formation cells) and osteoclasts (bone resorption cells) can differentiate among different types of loads. Specifically, the regulation effects and the related mechanisms of the biomechanical and biophysical environments on bone need further exploration, and the incorporation of experimental research with theoretical simulations is essential. PMID:26119589

  19. Improvement of thermoelectric efficiency of the polyaniline molecular junction by the doping process.

    Science.gov (United States)

    Golsanamlou, Zahra; Tagani, Meysam Bagheri; Soleimani, Hamid Rahimpour

    2015-05-28

    Thermoelectric properties of a polyaniline molecular junction with face centered cubic electrodes are investigated using the Green function formalism in a linear response regime in the presence of the doping process. Doping causes the increase of thermopower and the figure of merit (ZT) and the decrease of electrical conductance as found experimentally in the work of Li et al., (Synthetic. Metals, 2010, 160, 1153-1158). We also find that the ZT increases with the molecular length in short polyanilines. [Golsanamlou et al., Phys. Chem. Chem. Phys., 2000, 35, 3523]. PMID:25929682

  20. Vibrational spectral emission of fractional-principal-quantum-energy-level hydrogen molecular ion

    Energy Technology Data Exchange (ETDEWEB)

    Mills, R.L.; Ray, P. [BlackLight Power, Inc., Cranbury, NJ (United States)

    2002-05-01

    From a solution of a Schroedinger-type wave equation with a nonradiative boundary condition based on Maxwell's equations, Mills solves the hydrogen atom, the hydrogen molecular ion, the hydrogen molecule and predicts corresponding species having fractional principal quantum numbers. Atomic hydrogen may undergo a catalytic reaction with certain atomized elements and ions which singly or multiply ionize at integer multiples of the potential energy of atomic hydrogen, m27.2 eV wherein m is an integer. The reaction involves a nonradiative energy transfer to form a hydrogen atom H(1/p) that is lower in energy than unreacted atomic hydrogen that corresponds to a fractional principal quantum number (n=1/p=1/integer replaces the well known parameter n=integer in the Rydberg equation for hydrogen excited states). One such atomic catalytic system involves argon ions. The reaction Ar{sup +} to Ar{sup 2+} has a net enthalpy of reaction of 27.63 eV, which is equivalent to m=1. Thus, it may serve as a catalyst to form H(1/2). Also, the second ionization energy of helium is 54.4 eV; thus, the ionization reaction of He{sup +} to He{sup 2+} has net enthalpy of reaction of 54.4 eV which is equivalent to 2x27.2 eV. The products of the catalysis reaction H(1/3) may further serve as catalysts to form H(1/4) and H(1/2). H(1/p) may react with a proton to form an excited state molecular ion H{sub 2}{sup *}(1/p){sup +} that has a bond energy and vibrational levels that are p{sup 2} times those of the molecular ion comprising uncatalyzed atomic hydrogen where p is an integer. Thus, the excited state spectrum of H{sub 2}{sup *}[n=1/4:n{sup *}=2]{sup +} was predicted to comprise rotationally broadened vibrational transitions at 1.185 eV increments to the dissociation limit of H{sub 2}[n=1/4]{sup +}. E{sub D}=42.88 eV (28.92 nm). Extreme ultraviolet spectroscopy was recorded on microwave discharges of argon or helium with 10% hydrogen in the range 10-65 nm. Novel emission lines assigned to vibrational transitions of H{sub 2}{sup *}[n=1/4:n{sup *}=2]{sup +} were observed in this range with energies of v1.185 eV, v=17-38 that terminated at about 28.9 nm. In addition, fractional molecular hydrogen rotational transitions were assigned to previously unidentified lines in the Solar coronal spectrum that matched theoretical predictions to five figures. (author)

  1. Impaired Global, and Compensatory Local, Biological Motion Processing in People with High Levels of Autistic Traits

    OpenAIRE

    van Boxtel, Jeroen J. A.; Lu, Hongjing

    2013-01-01

    People with Autism Spectrum Disorder (ASD) are hypothesized to have poor high-level processing but superior low-level processing, causing impaired social recognition, and a focus on non-social stimulus contingencies. Biological motion perception provides an ideal domain to investigate exactly how ASD modulates the interaction between low and high-level processing, because it involves multiple processing stages, and carries many important social cues. We investigated individual differences amo...

  2. MULTI LEVEL SEMANTIC EXTRACTION FOR CRICKET VIDEO BY TEXT PROCESSING

    Directory of Open Access Journals (Sweden)

    Dr. SUNITHA ABBURU

    2010-10-01

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

  3. La modificacin covalente de protenas. Un nivel cualitativamente superior de la informacin molecular / Covalent Modifications of Proteins. A qualitative higher level of molecular information

    Scientific Electronic Library Online (English)

    Rolando A, Hernndez Fernndez.

    2014-02-01

    Full Text Available Introduccin: La informacin molecular es una propiedad principal de las biomacromolculas, especialmente protenas y cidos nucleicos, que permite la realizacin de funciones con un alto grado de especificidad. Ella deriva de la variedad en los componentes de las macromolculas. Objetivo: Demostrar [...] que la modificacin covalente de protenas constituye un nivel nuevo y superior de informacin molecular. Mtodo: Se analizaron artculos de los ltimos 5 aos, publicados en revistas nacionales y de circulacin 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 caractersticas principales del proceso y posteriormente algunos de los efectos principales de la modificacin covalente sobre las funciones y propiedades de las protenas. Conclusiones: La modificacin covalente es un mecanismo que ampla el campo de accin de las protenas permitiendo un rpido cambio en sus propiedades funcionales y, por lo tanto, constituye un nivel nuevo y cualitativamente superior de informacin 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.

  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. Shark tales: a molecular species-level phylogeny of sharks (Selachimorpha, Chondrichthyes).

    Science.gov (United States)

    Vlez-Zuazo, Ximena; Agnarsson, Ingi

    2011-02-01

    Sharks are a diverse and ecologically important group, including some of the ocean's largest predatory animals. Sharks are also commercially important, with many species suffering overexploitation and facing extinction. However, despite a long evolutionary history, commercial, and conservation importance, phylogenetic relationships within the sharks are poorly understood. To date, most studies have either focused on smaller clades within sharks, or sampled taxa sparsely across the group. A more detailed species-level phylogeny will offer further insights into shark taxonomy, provide a tool for comparative analyses, as well as facilitating phylogenetic estimates of conservation priorities. We used four mitochondrial and one nuclear gene to investigate the phylogenetic relationships of 229 species (all eight Orders and 31 families) of sharks, more than quadrupling the number of taxon sampled in any prior study. The resulting Bayesian phylogenetic hypothesis agrees with prior studies on the major relationships of the sharks phylogeny; however, on those relationships that have proven more controversial, it differs in several aspects from the most recent molecular studies. The phylogeny supports the division of sharks into two major groups, the Galeomorphii and Squalimorphii, rejecting the hypnosqualean hypothesis that places batoids within sharks. Within the squalimorphs the orders Hexanchiformes, Squatiniformes, Squaliformes, and Pristiophoriformes are broadly monophyletic, with minor exceptions apparently due to missing data. Similarly, within Galeomorphs, the orders Heterodontiformes, Lamniformes, Carcharhiniformes, and Orectolobiformes are broadly monophyletic, with a couple of species 'misplaced'. In contrast, many of the currently recognized shark families are not monophyletic according to our results. Our phylogeny offers some of the first clarification of the relationships among families of the order Squaliformes, a group that has thus far received relatively little phylogenetic attention. Our results suggest that the genus Echinorhinus is not a squaliform, but rather related to the saw sharks, a hypothesis that might be supported by both groups sharing 'spiny' snouts. In sum, our results offer the most detailed species-level phylogeny of sharks to date and a tool for comparative analyses. PMID:21129490

  6. Download Process in Distributed Systems, Flow-level vs. Packet-level Simulation Analysis

    OpenAIRE

    Dandoush, Abdulhalim; Jean-Marie, Alain

    2009-01-01

    Parallelism in the download process of large files is an efficient mechanism for distributed systems. In such systems, some peers (clients) exploit the power of parallelism to download blocks of data stored in a distributed way over some other peers (servers). Determining response times in parallel downloading with capacity constraints on both the client downloads and server uploads necessitates understanding the instantaneous shares of the bandwidths of each client/server is devoted to each ...

  7. Download Process in Distributed Systems, Flow-level Algorithm vs. Packet-level Simulation Model

    OpenAIRE

    Dandoush, Abdulhalim; Jean-Marie, Alain

    2009-01-01

    Parallelism in the download process of large files is an efficient mechanism for distributed systems. In such systems, some peers (clients) exploit the power of parallelism to download blocks of data stored in a distributed way over some other peers (servers). Determining response times in parallel downloading with capacity constraints on both the client downloads and server uploads necessitates understanding the instantaneous shares of the bandwidths of each client/server is devoted to each ...

  8. The evolution of plants and animals under domestication: the contribution of studies at the molecular level.

    Science.gov (United States)

    Jope, E M

    1976-07-27

    Protein molecules are essential catalysts in life processes and also form much of the substance of living material. Their three dimensional structures determine their biological function. Their biosynthesis is primarily determined by arrays of nucleic acid macromolecules (DNA and RNA), and the amino acid sequences that constitute their long spatially organized peptide-chain molecules reflect at one remove this DNA coding system, and thus record a step-by-step history of some of the viable genetic events (natural or man-controlled) that have created the organism and the breed. Amino acid sequences can be used to trace the progress of controlled breeding in two ways: by extrapolation back from living breeds, and by analysis of ancient protein material. Of the latter, bone or tendon or skin collagens and hair keratins are the most perfectly preserved as molecular structures through 20,000 years and indeed much longer. Amino acid sequences are expensive to determine (collagen has 1052 amino acid residues), and the potential of this palaeobiological information has been as yet little exploited. The first approach has, however, been more explored, in both plants and animals. Several protein systems must be studied in conjunction to reveal the phylogenetic threads in any one breed. As the three dimensional quaternary structure of protein molecules becomes more appreciated in relation to biological function, and as new techniques and procedures are developed, amino acid sequence data can become more informative in our ultimate understanding of early selective breeding. PMID:11513

  9. Biologia molecular do processo de infeco 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 o agente causal da galha-da-coroa, doena que afeta a maioria das plantas dicotiledneas e caracteriza-se pelo crescimento de tumores na juno entre o caule e a raiz (coroa). A formao desses tumores o resultado de um processo natural de transferncia de genes de Agro [...] bacterium spp. para o genoma da planta infetada. Esses genes esto contidos em um plasmdio de alto peso molecular (120 a 250 kb), denominado Ti ("tumor inducing"), presente em todas as linhagens patognicas de Agrobacterium spp. Duas regies do plasmdio Ti esto diretamente envolvidas na induo do tumor: a regio-T, que corresponde ao segmento de DNA transferido para a clula vegetal, e a regio de virulncia (regio vir), que contm genes envolvidos na sntese de protenas responsveis pelo processo de transferncia da regio-T. Esta regio, uma vez transferida e integrada no genoma da clula vegetal, passa a ser denominada de T-DNA ("transferred DNA"). Os genes presentes no T-DNA codificam enzimas envolvidas na via de biossntese de reguladores de crescimento, auxinas e citocininas. A sntese desses reguladores pelas clulas transformadas causa um desbalano hormonal, levando formao do tumor no local da infeco. Outro grupo de genes presentes no T-DNA codifica enzimas responsveis pela sntese de opinas, que so catabolisadas especificamente pela bactria colonizadora, como fonte de nutrientes. O conhecimento preliminar das bases moleculares envolvidas no processo de infeco de uma planta hospedeira por Agrobacterium spp., permitiu a utilizao desta bactria como vetor natural de transformao gentica 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.

  10. Multiprobe Spectroscopic Inverstigation of Molecular-level Behavior within Aqueous 1-Butyl-3-methylimidazolium Tetrafluoroborate

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, Abhra [Indian Institute of Technology, Delhi; Ali, Maroof [Indian Institute of Technology, Delhi; Baker, Gary A [ORNL; Tetin, Sergey Y. [Abbott Laboratories; Ruan, Qiaoqiao [Abbott Laboratories; Pandey, Siddharth [Indian Institute of Technology, Delhi

    2009-01-01

    In this work, an array of molecular-level solvent featuressincluding solute-solvent/solvent-solvent interactions, dipolarity, heterogeneity, dynamics, probe accessibility, and diffusionswere 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 probessa watersoluble betaine dye (betaine dye 33), N,N-diethyl-4-nitroaniline, and 4-nitroanilineswere employed to determine ET (a blend of dipolarity/polarizability and hydrogen bond donor contributions) and the Kamlet-Taft indices * (dipolarity/polarizability), R (hydrogen bond donor acidity), and (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].

  11. 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.

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

    OpenAIRE

    Yu Peiqiang

    2012-01-01

    Abstract In complex feed structures, there exist main chemical functional groups which are associated with nutrient utilization and availability and functionality. Each functional group has unique molecular structure therefore produce unique molecular vibration spectral profile. Feed processing has been used to improve nutrient utilization for many years. However, to date, there was little study on processing-induced changes of feed intrinsic structure and functional groups on a molecular bas...

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

    Science.gov (United States)

    Huang, Guoliang; Ma, Li; Yang, Xiaoyong; Yang, Xu

    2011-01-01

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

  14. Atomic and molecular processes generated by linearly polarized few-cycle laser pulses

    International Nuclear Information System (INIS)

    S-matrix theory is used to analyze different atomic and molecular processes in a linearly polarized few-cycle laser field. The energy spectra of high-order above-threshold ionization (HATI) are presented. Electron-atom potential scattering assisted by a few-cycle laser pulse is also analyzed. It is shown that the plateau structures in the energy spectra of the electron-atom potential scattering are dependent on the carrier-envelope phase (CEP) of the laser pulse, so that the cutoff positions of the plateaus can be controlled by changing the CEP. Regarding our analysis of the molecular HATI process, the angle-resolved spectra, obtained by different theoretical approaches, are also presented. (paper)

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  17. Indistinguishability and Interference in the Coherent Control of Atomic and Molecular Processes

    OpenAIRE

    Gong, Jiangbin; Brumer, Paul

    2010-01-01

    The subtle and fundamental issue of indistinguishability and interference between independent pathways to the same target state is examined in the context of coherent control of atomic and molecular processes, with emphasis placed on possible "which-way" information due to quantum entanglement established in the quantum dynamics. Because quantum interference between independent pathways to the same target state occurs only when the independent pathways are indistinguishable,...

  18. Theoretical study of the molecular bases that control photochemical processes with biological and nanotechnological interest

    OpenAIRE

    Saur Peris, Vicenta

    2013-01-01

    El trabajo desarrollado en la tesis doctoral que lleva por ttulo "Theoretical study of the molecular bases that control photochemical processes with biological and nanotechnological interest" se enmarca en las lneas de investigacin del grupo QCEXVAL (Quantum Chemistry of the Excited State University of Valencia), que naci en el seno del departamento de Qumica Fsica de la Universitat de Valncia en 1993. Se han abordado temas de inters metodolgico, biolgico y nanotecnolgico. La prime...

  19. General purpose molecular dynamics simulations fully implemented on graphics processing units

    Science.gov (United States)

    Anderson, Joshua A.; Lorenz, Chris D.; Travesset, A.

    2008-05-01

    Graphics processing units (GPUs), originally developed for rendering real-time effects in computer games, now provide unprecedented computational power for scientific applications. In this paper, we develop a general purpose molecular dynamics code that runs entirely on a single GPU. It is shown that our GPU implementation provides a performance equivalent to that of fast 30 processor core distributed memory cluster. Our results show that GPUs already provide an inexpensive alternative to such clusters and discuss implications for the future.

  20. Molecular Mechanisms of Processing Proteome Reorganization of Interphase Chromatin During Stress and Adaptation to Winter in Wheat

    Directory of Open Access Journals (Sweden)

    Ivanov R.S.

    2015-06-01

    Full Text Available Research of fundamental molecular and genetic processes of plant interaction with the environment, is a progressive field of understanding the fundamental problems of stress supramolecular biochemistry of developmental biology. The purpose of the work was the analysis of localization shielded to protease processing proteins of suprastructures of interphase chromatin matrix in the conditions of adaptation during vegetative phase of wheat to stressful environment factors. It is shown that in the conditions of perennial adaptation to cold shock of wheat at the level of chromatin suprastructures tightly bound to the nuclear matrix there is a total shielding of arginine-X sites to protease-processing. Perhaps these are zones that affect to the architecture organization of the cell nucleus that can help to survive in complex environmental conditions. According to the priorities in the study of agricultural plants, put forward by EPIC (The Epigenomics of Plants International Consortium in 2011 for the next decade, was included the point of necessity to understand the molecular basis of the interactions of genotype and environment that change the characteristics of plants in different conditions of the environment. These data will be useful for those who involved in the development of mathematical logic schemes of the theory and practice of biological specificity, and it could be included in the ontology of the stages plant growth and development.

  1. Molecular tools for the selective detection of nine diatom species biomarkers of various water quality levels.

    Science.gov (United States)

    Cimarelli, Lucia; Singh, Kumar Saurabh; Mai, Nguyen Thi Nhu; Dhar, Bidhan Chandra; Brandi, Anna; Brandi, Letizia; Spurio, Roberto

    2015-05-01

    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. PMID:26006124

  2. 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.

  3. 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

  4. Role of molecular dynamics on descriptions of shock-front processes

    International Nuclear Information System (INIS)

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

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

    CERN Document Server

    Burke, Philip George

    2011-01-01

    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 technologial importance. Basic mathematical results and general and widely used R-matrix computer programs are summarized in the appendices.

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

    OpenAIRE

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

    Science.gov (United States)

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

    2008-12-01

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

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

    OpenAIRE

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

    2012-01-01

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

  9. Molecular-level understanding of the water-gas-shift reaction on Rh(111)

    Energy Technology Data Exchange (ETDEWEB)

    Maestri, Matteo [Politecnico di Milano (Italy); Fritz-Haber-Institut, MPG, Berlin (Germany); Reuter, Karsten [Technische Universitaet, Muenchen (Germany); Fritz-Haber-Institut, MPG, Berlin (Germany)

    2011-07-01

    The identification of the reaction mechanism is the center piece for the atomic-scale understanding of a catalytic process and requires the kinetic assessment of all potential steps at the surface. At this level, processes of technological interest involve a large number of potential reactions and, due to the huge computational costs, are still largely outside the capabilities of a full density-functional theory (DFT) analysis. To this end we propose a hierarchical approach for the identification of prevalent reaction mechanisms by efficiently combining DFT and semi-empirical methods. The obtained computationally undemanding barrier estimates serve as initial approximate input for the identification of the prevalent paths that subsequently require refined kinetic parameters from explicit DFT calculations. As showcase we consider the water-gas-shift (WGS) and reverse reactions on Rh(111). Our results reveal that CO follows different chemical paths depending on the operating conditions. A carboxyl pathway is preferred for the consumption of CO, while its formation proceeds through the direct decomposition of carbon dioxide. These insights into the atomic-scale mechanism allow for a new understanding of the WGS system in full agreement with existing experimental evidence.

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

    Directory of Open Access Journals (Sweden)

    FranciscaMonteiro

    2012-11-01

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

  11. 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.

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

    International Nuclear Information System (INIS)

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

  13. Seeing the Light: Adapting Luminance Reveals Low-Level Visual Processes in the Attentional Blink

    Science.gov (United States)

    Giesbrecht, Barry; Bischof, Walter F.; Kingstone, Alan

    2004-01-01

    It is widely assumed that high-level visual processes subserve the attentional blink (AB). Recent evidence from studies of visual masking during the AB that were designed to directly test the contributions of high-level masking effects, however, have failed to provide empirical support for this position.The implication is that low-level visual

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

    CERN Document Server

    Sasaki, K

    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, controlled by an external agent. It is shown that the work larger than the maximum value limited by the second law of thermodynamics can be obtained in a single cycle of operation by chance, although the statistical average of the work never exceeds this limit and the maximum work is delivered if the process is reversible. The mechanism of the energy transductionis also discussed.

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

    CERN Document Server

    Pedersen, Andreas; Karssemeijer, Leendertjan; Cuppen, Herma; Jnsson, 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...

  16. Molecular dynamics simulation of mode-I-crack propagation and dislocation generation processes in ?-Fe

    International Nuclear Information System (INIS)

    The process of I-mode crack propagations in ?-Fe for uniaxial tension experiments are simulated by molecular dynamics (MD) methods. The formation process of dislocation and fracture mechanisms in the crack growing under various temperatures were studied. The results show that the crack propagation is a process of successive emission of dislocation. The dislocation-free zone and the stacking faults were initially formed at crack tip. When the stress KI increased into 0. 566 MPam1/2, one layer of atoms near crack tip would be separated into two layers which produced a dislocation. The first dislocation was emitted when stress KI reached 0.669 MPam1/2. With the temperature increasing, the critical stress intensity factor decreased gradually and the dislocation emission correspondingly became faster as well. (authors)

  17. Study on the nitrite and nitrate levels changes by drying and frying processing in vegetables

    Directory of Open Access Journals (Sweden)

    E Sadeghi

    2014-07-01

    Conclusion: Reducing nitrite and nitrate levels does not occur in frying and drying processing in vegetables. Therefore, it is essential to study other methods of processing or control of nitrate and nitrite levels in the vegetables. It is crucial to monitor and control the quality of this product and studying other food processing because of the daily intake of vegetables and potential risks of nitrate and nitrite accumulation and its association with some illnesses and gastrointestinal tract cancers. .

  18. Molecular-level removal of proteinaceous contamination from model surfaces and biomedical device materials by air plasma treatment.

    Science.gov (United States)

    Banerjee, K K; Kumar, S; Bremmell, K E; Griesser, H J

    2010-11-01

    Established methods for cleaning and sterilising biomedical devices may achieve removal of bioburden only at the macroscopic level while leaving behind molecular levels of contamination (mainly proteinaceous). This is of particular concern if the residue might contain prions. We investigated at the molecular level the removal of model and real-life proteinaceous contamination from model and practical surfaces by air plasma (ionised air) treatment. The surface-sensitive technique of X-ray photoelectron spectroscopy (XPS) was used to assess the removal of proteinaceous contamination, with the nitrogen (N1s) photoelectron signal as its marker. Model proteinaceous contamination (bovine serum albumin) adsorbed on to a model surface (silicon wafer) and the residual proteinaceous contamination resulting from incubating surgical stainless steel (a practical biomaterial) in whole human blood exhibited strong N1ssignals [16.8 and 18.5 atomic percent (at.%), respectively] after thorough washing. After 5min air plasma treatment, XPS detected no nitrogen on the sample surfaces, indicating complete removal of proteinaceous contamination, down to the estimated XPS detection limit 10ng/cm(2). Applying the same plasma treatment, the 7.7at.% nitrogen observed on a clinically cleaned dental bur was reduced to a level reflective of new, as-received burs. Contact angle measurements and atomic force microscopy also indicated complete molecular-level removal of the proteinaceous contamination upon air plasma treatment. This study demonstrates the effectiveness of air plasma treatment for removing proteinaceous contamination from both model and practical surfaces and offers a method for ensuring that no molecular residual contamination such as prions is transferred upon re-use of surgical and dental instruments. PMID:20850199

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

    International Nuclear Information System (INIS)

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

  20. 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.

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

    Science.gov (United States)

    Lazetic, Predrag

    2010-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Kimminau, Giles; Nagler, Bob; Higginbotham, Andrew; Murphy, William J; Wark, Justin S [Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Park, Nigel [AWE, Aldermaston, Reading RG7 4PR (United Kingdom); Hawreliak, James; Kalantar, Daniel H; Lorenzana, Hector E; Remington, Bruce A [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Kadau, Kai; Germann, Timothy C [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Bringa, Eduardo M [Institudo de Ciencias Basicas, Universidad Nacional de Cuyo, Mendoza CP 5500 (Argentina)], E-mail: giles.kimminau@physics.ox.ac.uk

    2008-12-17

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-06-19

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

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

    Science.gov (United States)

    Kimminau, Giles; Nagler, Bob; Higginbotham, Andrew; Murphy, William J.; Park, Nigel; Hawreliak, James; Kadau, Kai; Germann, Timothy C.; Bringa, Eduardo M.; Kalantar, Daniel H.; Lorenzana, Hector E.; Remington, Bruce A.; Wark, Justin S.

    2008-12-01

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

  5. Statistical mechanics of neocortical interactions: large-scale EEG influences on molecular processes

    OpenAIRE

    Ingber, Lester

    2012-01-01

    Recent calculations further supports the premise that large-scale synchronous firings of neurons may affect molecular processes. The context is scalp electroencephalography (EEG) during short-term memory (STM) tasks. The mechanism considered is $\\mathbf{\\Pi} = \\mathbf{p} + q \\mathbf{A}$ (SI units) coupling, where $\\mathbf{p}$ is the momenta of free $\\mathrm{Ca}^{2+}$ waves $q$ the charge of $\\mathrm{Ca}^{2+}$ in units of the electron charge, and $\\mathbf{A}$ the magnetic vector potential of c...

  6. Low temperature pulse radiolysis as a method to study fast isomerization processes in molecular cations

    International Nuclear Information System (INIS)

    Application of the low-temperature pulse radiolysis to the studies of molecular cation transformations has been discussed. It has been shown that such parameters as: concentration of the substrate, ionization potentials of the solution components and the temperature of the matrix play important role in the charge transfer processes. These parameters have to be chosen carefully in order to secure a complete formation of the substrate radical cation prior to observation of its unimolecular transformations. A successful application of the low-temperature pulse radiolytic method to the studies of valence isomerization and conformational rotamerism of radical cations has been reviewed. (author)

  7. Molecular-Level Simulation of Electrolyte System Solubility and Chemical Speciation.

    Czech Academy of Sciences Publication Activity Database

    Jirsk, Jan; kvor, J.; Smith, W.R.; Nezbeda, Ivo

    2010, s. 1. ISBN N. [International Workshop "Molecular Modeling and Simulation for Industrial Applications".. Wrzburg (DE), 22.03.2010-23.03.2010] Institutional research plan: CEZ:AV0Z40720504 Keywords : electrolyte system solubility * chemical speciation Subject RIV: CF - Physical ; Theoretical Chemistry http://www.processnet.org/index.php?id=1161&suffix=pdf&nonactive=1&lang=de&site=processnet_media

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

    International Nuclear Information System (INIS)

    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

  10. Research Concerning Influence of Worm Face Gear Finishing Process upon Noise and Vibration Level

    Directory of Open Access Journals (Sweden)

    Ion Gavril??

    2011-11-01

    Full Text Available A study was performed to evaluate noise and vibration level of worm face gear finish. Vibration and noise monitoring data were gathered from 6 sets of worm plane gears run during a evaluation study. A drop o vibration level was successful recording, noise level remain almost the same as noise level record before finishing process was perform. A solution for fly cutter hobbing's particular problem was propose.

  11. Extending pathways and processes using molecular interaction networks to analyse cancer genome data

    Directory of Open Access Journals (Sweden)

    Krasnogor Natalio

    2010-12-01

    Full Text Available Abstract Background Cellular processes and pathways, whose deregulation may contribute to the development of cancers, are often represented as cascades of proteins transmitting a signal from the cell surface to the nucleus. However, recent functional genomic experiments have identified thousands of interactions for the signalling canonical proteins, challenging the traditional view of pathways as independent functional entities. Combining information from pathway databases and interaction networks obtained from functional genomic experiments is therefore a promising strategy to obtain more robust pathway and process representations, facilitating the study of cancer-related pathways. Results We present a methodology for extending pre-defined protein sets representing cellular pathways and processes by mapping them onto a protein-protein interaction network, and extending them to include densely interconnected interaction partners. The added proteins display distinctive network topological features and molecular function annotations, and can be proposed as putative new components, and/or as regulators of the communication between the different cellular processes. Finally, these extended pathways and processes are used to analyse their enrichment in pancreatic mutated genes. Significant associations between mutated genes and certain processes are identified, enabling an analysis of the influence of previously non-annotated cancer mutated genes. Conclusions The proposed method for extending cellular pathways helps to explain the functions of cancer mutated genes by exploiting the synergies of canonical knowledge and large-scale interaction data.

  12. PET molecular imaging of peripheral and central inflammatory processes targeting the TSPO 18 kDa

    International Nuclear Information System (INIS)

    The purpose of this study was to determine the in vivo potential of the TSPO 18 kDa as a bio-marker of inflammation, with the use of its radioligand [18F]DPA-714, to non-invasively quantify the inflammatory state within the scope of various pathologies. Multiple animal models of various inflammatory diseases, to include: inflammatory bowel disease, neuro-inflammation, and septic shock, were developed and put in place by adapted measures. The animals well-being and the subsequent inflammation was evaluated. The inflammatory state was measured using quantitative PET imaging with the TSPO radioligand [18F]DPA-714 and correlated to the expression of conventional inflammatory markers using microscopy. Based on the observed data, we were able to distinguish control groups from treated groups when using [18F]DPA-714. This TSPO radioligand permitted us to quantify the inflammatory level and to observe evolutionary changes in the inflammatory state of the disease in multiple models. The PET results, using the [18F]DPA-714 signal was correlated with an increased TSPO expression at cellular level. Results indicate that [18F]DPA-714 is a suitable tracer for studying inflammation of multiple diseases. [18F]DPA-714 could be a good molecular probe to non-invasively evaluate the level and localization of inflammation. Moreover, in vivo imaging using this TSPO ligand is potentially a powerful tool to stage and certainly to follow the evolution and therapeutic efficiency at molecular level in inflammatory diseases. (author)

  13. Dialkylthio Substitution: An Effective Method to Modulate the Molecular Energy Levels of 2D-BDT Photovoltaic Polymers.

    Science.gov (United States)

    Yao, Huifeng; Zhang, Hao; Ye, Long; Zhao, Wenchao; Zhang, Shaoqing; Hou, Jianhui

    2016-02-17

    Dialkylthio-substituted thienyl-benzodithiophene (BDT-DST) was designed and synthesized as a building block to modulate the molecular levels of the conjugated polymers, and three copolymers named PDST-BDD, PDST-TT and PDST-DPP were prepared and applied in polymer solar cells (PSCs). Theoretical calculations and electrochemical cyclic voltammetry (CV) measurement suggested that the dialkylthio group could decrease the molecular energy levels of the resulting polymers distinctly. The open-circuit voltage (VOC) of PSC devices based on PDST-BDD, PDST-TT, and PDST-DPP are as high as 1.0, 0.98, and 0.88 V, respectively, which are ?0.15 V higher than those of the corresponding alky-substituted analogues. Moreover, the influence of the dialkylthio group on the absorption spectra, crystalline properties, hole mobilities, and blend morphologies of the polymers was also investigated. The results indicate that the dialkythio substitution is an effective method to modulate the molecular energy levels and that the BDT-DST unit has potential for constructing high-efficiency photovoltaic polymers. PMID:26359953

  14. Thickness control of molecular beam epitaxy grown layers at the 0.010.1 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)

  15. Statistical mechanics of neocortical interactions: Large-scale EEG influences on molecular processes.

    Science.gov (United States)

    Ingber, Lester

    2016-04-21

    Calculations further support the premise that large-scale synchronous firings of neurons may affect molecular processes. The context is scalp electroencephalography (EEG) during short-term memory (STM) tasks. The mechanism considered is Π=p+qA (SI units) coupling, where p is the momenta of free Ca(2+) waves, q the charge of Ca(2+) in units of the electron charge, and A the magnetic vector potential of current I from neuronal minicolumnar firings considered as wires, giving rise to EEG. Data has processed using multiple graphs to identify sections of data to which spline-Laplacian transformations are applied, to fit the statistical mechanics of neocortical interactions (SMNI) model to EEG data, sensitive to synaptic interactions subject to modification by Ca(2+) waves. PMID:26874226

  16. Failure of single electron descriptions of molecular orbital collision processes. [Electron promotion mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Elston, S.B.

    1978-01-01

    Inner-shell excitation occurring in low and moderate (keV range) energy collisions between light atomic and ionic systems is frequently describable in terms of molecular promotion mechanisms, which were extensively explored both theoretically and experimentally. The bulk of such studies have concentrated on processes understandable through the use of single- and independent-electron models. Nonetheless, it is possible to find cases of inner-shell excitation in relatively simple collision systems which involve nearly simultaneous multiple-electron transitions and transitions induced by inherently two-electron interactions. Evidence for these many- and nonindependent-electron phenomena in inner-shell excitation processes and the importance of considering such effects in the interpretation of collisionally induced excitation spectra is discussed. 13 references.

  17. Molecular Interdiffusion between Stacked Layers by Solution and Thermal Annealing Processes in Organic Light Emitting Devices.

    Science.gov (United States)

    Ohisa, Satoru; Pu, Yong-Jin; Yamada, Norifumi L; Matsuba, Go; Kido, Junji

    2015-09-23

    In organic light emitting devices (OLEDs), interfacial structures between multilayers have large impacts on the characteristics of OLEDs. Herein, we succeeded in revealing the interdiffusion in solution processed and thermal annealed OLEDs by neutron reflectometry. We investigated interfaces between a polymer under layer and small molecules upper layer. The small molecules diffused into the swollen polymer layer during the interfacial formation by the solution process, but the polymer did not diffuse into the small molecules layer. At temperatures close to the glass transition temperatures of the materials, asymmetric molecular diffusion was observed. We elucidated the effects of the interdiffusion on the characteristics of OLEDs. Partially mixing the interface improved the current efficiencies due to suppressed triplet-polaron quenching at the interface. Controlling and understanding the interfacial structures of the miultilayers will be more important to improve the OLED characteristics. PMID:26331696

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-12-14

    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.

  19. A molecular dynamics study of structural transition of Ti during the rapid quenching process

    International Nuclear Information System (INIS)

    The structural transitions of Ti during two different quenching processes (Q1: 7.51011 K/s, Q2: 2.01014 K/s) were studied using molecular dynamics simulations. The calculated pair-correlation function agrees acceptably with available experimental data. This work gives the structural properties, including the variations with temperature of pair-correlation function, bond-angle distribution function, bond pairs and Voronoi indices, in both rapid quenching processes. Our results indicated that the liquid Ti transformed to hcp phase at the temperature about of 400 K under the quenching condition Q1 while the liquid Ti was frozen into a glass state at the temperature about of 800 K under the quenching condition Q2.

  20. 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

  1. Femtosecond Laser Processing of Germanium: An Ab Initio Molecular Dynamics Study

    CERN Document Server

    Ji, Pengfei

    2016-01-01

    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 imposing the Nose Hoover thermostat to the electronic subsystem lasting for ~100 fs and continuing with 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 the irradiated germanium distinguishes from the usual germanium crystal by analyzing their melting and dynamic properties.

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

    International Nuclear Information System (INIS)

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

  3. MALDI-TOF mass spectrometry imaging reveals molecular level changes in ultrahigh molecular weight polyethylene joint implants in correlation with lipid adsorption.

    Science.gov (United States)

    Frhlich, Sophie M; Archodoulaki, Vasiliki-Maria; Allmaier, Gnter; Marchetti-Deschmann, Martina

    2014-10-01

    Ultrahigh molecular weight polyethylene (PE-UHMW), a material with high biocompatibility and excellent mechanical properties, is among the most commonly used materials for acetabular cup replacement in artificial joint systems. It is assumed that the interaction with synovial fluid in the biocompartment leads to significant changes relevant to material failure. In addition to hyaluronic acid, lipids are particularly relevant for lubrication in an articulating process. This study investigates synovial lipid adsorption on two different PE-UHMW materials (GUR-1050 and vitamin E-doped) in an in vitro model system by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry imaging (MSI). Lipids were identified by high performance thin layer chromatography (HP-TLC) and tandem mass spectrometry (MS/MS) analysis, with an analytical focus on phospholipids and cholesterol, both being species of high importance for lubrication. Scanning electron microscopy (SEM) analysis was applied in the study to correlate molecular information with PE-UHMW material qualities. It is demonstrated that lipid adsorption preferentially occurs in rough or oxidized polymer regions. Polymer modifications were colocalized with adsorbed lipids and found with high density in regions identified by SEM. Explanted, the in vivo polymer material showed comparable and even more obvious polymer damage and lipid adsorption when compared with the static in vitro model. A three-dimensional reconstruction of MSI data from consecutive PE-UHMW slices reveals detailed information about the diffusion process of lipids in the acetabular cup and provides, for the first time, a promising starting point for future studies correlating molecular information with commonly used techniques for material analysis (e.g., Fourier-transform infrared spectroscopy, nanoindentation). PMID:25215499

  4. Anthraquinone-based demultiplexer and other multiple operations at the molecular level

    Indian Academy of Sciences (India)

    Navneet Kaur; Subodh Kumar

    2014-01-01

    Anthraquinone-based chemosensor L with pyridine units as additional functional groups has been found to show pH-dependent multiple coordinationmodes towards differentmetal ions (Co2+, Ni2+ and Cu2+). Based on these different absorption changes, this differential colorimetric chemosensor L has found promising applications as a multiple-mode molecular logic system, i.e., OR, three - input NOR, three - input INHIBIT, TRANSFER and 1:2 DEMUX.

  5. 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.

  6. Vapor pressure dependence of spectral width of EIT in Lambda-level cesium molecular system

    OpenAIRE

    Chen, Hui; Li, Hebin; Rostovtsev, Yuri V.; Gubin, Mikhail A.; Sautenkov, Vladimir A.; Scully, Marlan O.

    2009-01-01

    We have studied electromagnetically induced transparency (EIT) in diatomic cesium molecules in a vapor cell by using tunable diode lasers. We have observed a sub-natural Lambda-resonance in an absorption molecular band at different cesium vapor pressures. The width of the EIT resonance shows a linear dependence on cesium vapor pressure. Narrow Lambda-resonances in molecules can be used as frequency references for femtosecond laser frequency combs.

  7. Molecular dynamics simulation of the melting process in Ag27Cu13 coreshell nanoalloy

    International Nuclear Information System (INIS)

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

  8. Quantum control of a molecular ionization process by using Fourier-synthesized laser fields

    Science.gov (United States)

    Ohmura, Hideki; Saito, Naoaki

    2015-11-01

    In photoexcitation processes, if the motion of excited electrons can be precisely steered by the instantaneous electric field of an arbitrary waveform of a Fourier-synthesized laser field, the resultant matter response can be achieved within one optical cycle, usually within the attosecond (1 as =10-18s) regime. Fourier synthesis of laser fields has been achieved in various ways. However, the general use of Fourier-synthesized laser fields for the control of matter is extremely limited. Here, we report the quantum control of a nonlinear response of a molecular ionization process by using Fourier-synthesized laser fields. The directionally asymmetric molecular tunneling ionization induced by intense (5.0 1012W /c m2) Fourier-synthesized laser fields consisting of fundamental, second-, third-, and fourth-harmonic light achieves the orientation-selective ionization; we utilized the orientation-selective ionization for measurement of the relative phase differences between the fundamental and each harmonic light. Our findings impact not only light-wave engineering but also the control of matter, possibly triggering the creation and establishment of a new methodology that uses Fourier-synthesized laser fields.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-01-01

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

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

    Science.gov (United States)

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

    2015-12-01

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

  11. 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, Lusa; 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

  12. 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.

  13. Molecular mechanism of the adsorption process of an iodide anion into liquid-vapor interfaces of water-methanol mixtures

    Science.gov (United States)

    Annapureddy, Harsha V. R.; Dang, Liem X.

    2012-12-01

    To enhance our understanding of the molecular mechanism of ion adsorption to the interface of mixtures, we systematically carried out a free energy calculations study involving the transport of an iodide anion across the interface of a water-methanol mixture. Many body affects are taken into account to describe the interactions among the species. The surface propensities of I- at interfaces of pure water and methanol are well understood. In contrast, detailed knowledge of the molecular level adsorption process of I- at aqueous mixture interfaces has not been reported. In this paper, we explore how this phenomenon will be affected for mixed solvents with varying compositions of water and methanol. Our potential of mean force study as function of varying compositions indicated that I- adsorption free energies decrease from pure water to pure methanol but not linearly with the concentration of methanol. We analyze the computed density profiles and hydration numbers as a function of concentrations and ion positions with respect to the interface to further explain the observed phenomenon.

  14. Molecular Mechanism of the Adsorption Process of an Iodide Anion into Liquid-Vapor Interfaces of Water-Methanol Mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Annapureddy, Harsha V.; Dang, Liem X.

    2012-12-07

    To enhance our understanding of the molecular mechanism of ion adsorption to the interface of mixtures, we systematically carried out a free energy calculations study involving the transport of an iodide anion across the interface of a water-methanol mixture. Many body affects are taken into account to describe the interactions among the species. The surface propensities of I- at interfaces of pure water and methanol are well understood. In contrast, detailed knowledge of the molecular level adsorption process of I- at aqueous mixture interfaces has not been reported. In this paper, we explore how this phenomenon will be affected for mixed solvents with varying compositions of water and methanol. Our potential of mean force study as function of varying compositions indicated that I- adsorption free energies decrease from pure water to pure methanol but not linearly with the concentration of methanol. We analyze the computed density profiles and hydration numbers as a function of concentrations and ion positions with respect to the interface to further explain the observed phenomenon. This work was supported by the U.S. Department of Energy (DOE), Office of Basic Energy Sciences (BES), Division of Chemical Sciences, Geosciences, and Biosciences. Pacific Northwest National Laboratory is a multiprogram national laboratory operated for DOE by Battelle. The calculations were carried out using computer resources provided by BES.

  15. Low-level wastewater treatment facility process control operational test report

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Yu Peiqiang

    2012-12-01

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

  17. Towards a seamless integration between process modeling descriptions at Business and Production levels - work in progress

    OpenAIRE

    Gerber, Tobias; Theorin, Alfred; Johnsson, Charlotta

    2012-01-01

    To fulfill increasing requirements in the manufacturing sector, companies are faced with several challenges. Three major challenges have been identified regarding time-to-market, vertical feedback loops and level of automation. Grafchart, a graphical language aimed for supervisory control applications, can be used from the process-planning phase, through the implementation phase and all the way to the phase for execution of the process control logics, on the lower levels of the Automation tri...

  18. An instrumentation and control philosophy for high-level nuclear waste processing facilities

    International Nuclear Information System (INIS)

    The purpose of this paper is to present an instrumentation and control philosophy which may be applied to high-level nuclear waste processing facilities. This philosophy describes the recommended criteria for automatic/manual control, remote/local control, remote/local display, diagnostic instrumentation, interlocks, alarm levels, and redundancy. Due to the hazardous nature of the process constituents of a high-level nuclear waste processing facility, it is imperative that safety and control features required for accident-free operation and maintenance be incorporated. A well-instrumented and controlled process, while initially more expensive in capital and design costs, is generally safer and less expensive to operate. When the long term cost savings of a well designed process is coupled with the high savings enjoyed by accident avoidance, the benefits far outweigh the initial capital and design costs

  19. Molecular studies on the ecology of Listeria monocytogenes in the smoked fish processing industry.

    Science.gov (United States)

    Norton, D M; McCamey, M A; Gall, K L; Scarlett, J M; Boor, K J; Wiedmann, M

    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 commercial PCR system (BAX for Screening/Listeria monocytogenes), including 57 (27.7%) environmental samples (n = 206), 8 (7.8%) raw material samples (n = 102), 23 (18.1%) samples from fish in various stages of processing(n = 127), and 7 (7.3%) finished product samples (n = 96). L. monocytogenes was isolated from 85 samples (16.0%) using culture methods. Used in conjunction with a 48-h enrichment in Listeria Enrichment Broth, the PCR system had a sensitivity of 91.8% and a specificity of 96.2%. To track the origin and spread of L. monocytogenes, isolates were fingerprinted by automated ribotyping. Fifteen different ribotypes were identified among 85 isolates tested. Ribotyping data established possible contamination patterns, implicating raw materials and the processing environment as potential sources of finished product contamination. Analysis of the distribution of ribotypes revealed that each processing facility had a unique contamination pattern and that specific ribotypes persisted in the environments of two facilities over time (P food processing environments. This information can be used to develop practical recommendations for improved control of this important food-borne pathogen in the food industry. PMID:11133446

  20. Molecular basis of processing-induced changes in protein structure in relation to intestinal digestion in yellow and green type pea (Pisum sativum L.): A molecular spectroscopic analysis.

    Science.gov (United States)

    Yu, Gloria Qingyu; Warkentin, Tom; Niu, Zhiyuan; Khan, Nazir A; Yu, Peiqiang

    2015-12-01

    The objectives of this study were (1) to quantify the protein inherent molecular structural features of green cotyledon (CDC Striker) and yellow cotyledon (CDC Meadow) pea (Pisum sativum L.) seeds using molecular spectroscopic technique (FT/IR-ATR); (2) measure the denaturation of protein molecular makeup in the two types of pea during dry roasting (120C for 60 min), autoclaving (120C for 60 min) or microwaving (for 5 min); and (3) correlate the heat-induced changes in protein molecular makeup to the corresponding changes in protein digestibility determined using modified three-step in vitro procedure. Compared with yellow-type, the green-type peas had higher (Pprotein content. Compared with yellow-type, the green-type peas had lower (Pprotein secondary structure makeup. All processing applications increased ?-helix:?-sheet ratio, with the largest (Pprotein within the green (r=-0. 86) and yellow (r=0.81) pea-types. However, across the pea types the correlation was not significant. Principal component and hierarchical cluster analyses on the entire spectral data from the amide region (ca. 1727-1480 cm(-1)) were able to visualize and discriminate the structural difference between pea varieties and processing treatments. This study shows that the molecular spectroscopy can be used as a rapid tool to screen the protein value of raw and heat-treated peas. PMID:26188704

  1. Paving the Way to Understand Autoantibody-Mediated Epilepsy on the Molecular Level.

    Science.gov (United States)

    Seebohm, Guiscard; Piccini, Ilaria; Strutz-Seebohm, Nathalie

    2015-01-01

    Correct function of neuronal networks is enabled by a delicate interplay among neurons communicating with each other. One of the keys is the communication at chemical synapses where neurotransmitters like glutamate, GABA, and glycine enable signal transfer over the synaptic cleft. Thereby, the neurotransmitters are released from the presynapse and bind as ligands to specific receptors at the postsynaptic side to allow for modulation of the postsynaptic membrane potentials. The postsynaptic electrical signal, which is highly modulated by voltage-gated ion channels, spreads over the dendritic tree and is thus integrated to allow for generation of action potentials at the axon hillock. This concert of receptors and voltage-gated ion channels depends on correct function of all its components. Misfunction of receptors and/or voltage-gated potassium channels (VGKC) leads to diverse adverse effects in patients. Such malfunctions can be the result of inherited genetic alterations or pharmacological side effects by drugs. Recently, autoantibodies targeting receptor or channel complexes like NMDAR, AMPAR, GABA-receptors, glycine receptors, LGI1 or CASPR2 (previously termed as VGKC-complex antibodies) have been discovered. The presence of specific autoantibodies against these targets associates with severe forms of antibody-mediated encephalitis. Understanding the molecular details of autoantibody actions on receptor and VGKC complexes is highly desirable and may open the path to develop specific therapies to treat humoral autoimmune encephalitis. Here, we summarize the current knowledge and discuss technical approaches to fill the gap of knowledge. These techniques include electrophysiology, biochemical approaches for epitope mapping, and in silico modeling to simulate molecular interactions between autoantibody and its molecular target. PMID:26217297

  2. ToF-SIMS imaging of molecular-level alteration mechanisms in Le Bonheur de vivre by Henri Matisse

    Science.gov (United States)

    Voras, Zachary E.; deGhetaldi, Kristin; Wiggins, Marcie B.; Buckley, Barbara; Baade, Brian; Mass, Jennifer L.; Beebe, Thomas P.

    2015-11-01

    Time-of-flight secondary ion mass spectrometry (ToF-SIMS) has recently been shown to be a valuable tool for cultural heritage studies, especially when used in conjunction with established analytical techniques in the field. The ability of ToF-SIMS to simultaneously image inorganic and organic species within a paint cross section at micrometer-level spatial resolution makes it a uniquely qualified analytical technique to aid in further understanding the processes of pigment and binder alteration, as well as pigment-binder interactions. In this study, ToF-SIMS was used to detect and image both molecular and elemental species related to CdS pigment and binding medium alteration on the painting Le Bonheur de vivre (1905-1906, The Barnes Foundation) by Henri Matisse. Three categories of inorganic and organic components were found throughout Le Bonheur de vivre and co-localized in cross-sectional samples using high spatial resolution ToF-SIMS analysis: (1) species relating to the preparation and photo-induced oxidation of CdS yellow pigments (2) varying amounts of long-chain fatty acids present in both the paint and primary ground layer and (3) specific amino acid fragments, possibly relating to the painting's complex restoration history. ToF-SIMS's ability to discern both organic and inorganic species via cross-sectional imaging was used to compare samples collected from Le Bonheur de vivre to artificially aged reference paints in an effort to gather mechanistic information relating to alteration processes that have been previously explored using ?XANES, SR-?XRF, SEM-EDX, and SR-FTIR. The relatively high sensitivity offered by ToF-SIMS imaging coupled to the high spatial resolution allowed for the positive identification of degradation products (such as cadmium oxalate) in specific paint regions that have before been unobserved. The imaging of organic materials has provided an insight into the extent of destruction of the original binding medium, as well as identifying unexpected organic materials in specific paint layers.

  3. 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.

  4. 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)

    Youssef Jihan

    2003-02-01

    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.

  5. 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. (author)

  6. 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.)

  7. The Influence of Levels of Processing on Recall from Working Memory and Delayed Recall Tasks

    Science.gov (United States)

    Loaiza, Vanessa M.; McCabe, David P.; Youngblood, Jessie L.; Rose, Nathan S.; Myerson, Joel

    2011-01-01

    Recent research in working memory has highlighted the similarities involved in retrieval from complex span tasks and episodic memory tasks, suggesting that these tasks are influenced by similar memory processes. In the present article, the authors manipulated the level of processing engaged when studying to-be-remembered words during a reading

  8. Low-Volatility Model Demonstrates Humidity Affects Environmental Toxin Deposition on Plastics at a Molecular Level.

    Science.gov (United States)

    Hankett, Jeanne M; Collin, William R; Yang, Pei; Chen, Zhan; Duhaime, Melissa

    2016-02-01

    Despite the ever-increasing prevalence of plastic debris and endocrine disrupting toxins in aquatic ecosystems, few studies describe their interactions in freshwater environments. We present a model system to investigate the deposition/desorption behaviors of low-volatility lake ecosystem toxins on microplastics in situ and in real time. Molecular interactions of gas-phase nonylphenols (NPs) with the surfaces of two common plastics, poly(styrene) and poly(ethylene terephthalate), were studied using quartz crystal microbalance and sum frequency generation vibrational spectroscopy. NP point sources were generated under two model environments: plastic on land and plastic on a freshwater surface. We found the headspace above calm water provides an excellent environment for NP deposition and demonstrate significant NP deposition on plastic within minutes at relevant concentrations. Further, NP deposits and orders differently on both plastics under humid versus dry environments. We attributed the unique deposition behaviors to surface energy changes from increased water content during the humid deposition. Lastly, nanograms of NP remained on microplastic surfaces hours after initial NP introduction and agitating conditions, illustrating feasibility for plastic-bound NPs to interact with biota and surrounding matter. Our model studies reveal important interactions between low-volatility environmental toxins and microplastics and hold potential to correlate the environmental fate of endocrine disrupting toxins in the Great Lakes with molecular behaviors. PMID:26752114

  9. SILVER NANOPARTICLES AND EXPERESSION OF MOLECULAR MARKERS IN LYMPHOCYTE ACTIVATION AND MARKER OF AUTOIMMUNE PROCESSES IN PERIPHERAL BLOOD OF PATIENTS WITH VIRAL CORNEAL PATHOLOGY

    Directory of Open Access Journals (Sweden)

    Ulyanov V.A.

    2015-08-01

    Full Text Available The influence of the nanoparticles of silver on the expression of molecular markers activation of lymphoid cells CD7+, CD25+, CD38+, CD45+, CD54+, CD95+, CD150+ and CD5+ – marker of the autoimmune process, as well as on phagocytic activity of neutrophils in patients with viral pathologies of the cornea was studied in vitro. In the Laboratory of Immunology, SI Institute of Eye Diseases and Tissue Therapy NAMS of Ukraine was developed technique of cultivation of peripheral blood lymphocytes with immunomodulation drugs, followed by determination of changes in the level of expression of molecular markers of lymphocyte activation. Assessment of the level of expression of molecular markers of activation of peripheral blood lymphocytes was performed method using a panel of monoclonal antibodies, CD5+, CD7+, CD25+, CD38+, CD45+, CD54+, CD95+ and CD 150+. The study was conducted in vitro with the peripheral lymphocytes the blood of 23 patients of viral pathology of the cornea. Our studies of the effects of nanosilver particles in vitro on the state of expression of molecular markers of activation of peripheral blood lymphocytes and phagocytic activity of neutrophils in patients with viral corneal pathology, showed a significant increase in the level of expression of the CD7+, CD25+, CD45+ and phagocytic activity of neutrophils after application silver nanoparticles.

  10. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1981-10-01

    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.

  12. 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 MaxwellBloch 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)

  13. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, Andreas, E-mail: andped10@gmail.com [Faculty of Physical Sciences and Science Institute, University of Iceland, VR-III, 107 Reykjavík (Iceland); Integrated Systems Laboratory, ETH Zurich, 8092 Zurich (Switzerland); Wikfeldt, Kjartan T. [Science Institute, University of Iceland, VR-III, 107 Reykjavík (Iceland); NORDITA, AlbaNova University Center, S-10691 Stockholm (Sweden); Karssemeijer, Leendertjan; Cuppen, Herma [Radboud University Nijmegen, Institute for Molecules and Materials, Heyendaalseweg 135, 6525 AJ Nijmegen (Netherlands); Jónsson, Hannes [Faculty of Physical Sciences and Science Institute, University of Iceland, VR-III, 107 Reykjavík (Iceland); Department of Applied Physics, Aalto University, Espoo FI-00076 (Finland)

    2014-12-21

    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 μs 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.

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

    International Nuclear Information System (INIS)

    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

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

    OpenAIRE

    Adel Merdassi; Peng Yang; Chodavarapu, Vamsy P.

    2015-01-01

    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...

  17. 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...

  18. Comparisons between molecular dynamics and hydrodynamics treatment of nonstationary thermal processes in a liquid

    Science.gov (United States)

    Okumura, Hisashi; Heyes, David M.

    2004-12-01

    Molecular dynamics (MD) and Navier-Stokes hydrodynamics have been performed to model thermal relaxation processes arising from an initially established nonequilibrium stationary state. A nanoscale two-layer Lennard-Jones (LJ) liquid system was constructed in which the two parts were initially at a different temperature, with a narrow transitional zone between the two layers that was spatially linear in temperature. The highest-temperature layer had widths of five or 20 LJ particle diameters. The hydrodynamics model used parametrized MD-derived transport coefficients and the LJ equation of state as input functions. The temporal and spatial temperature and density profiles produced by the two methods show good agreement, indicating that a hydrodynamics description is reliable even for nonstationary phenomena down to the scale of a few molecular diameters. We found that at certain locations the Navier-Stokes solution predicted that the pressure and temperature profiles relaxed in a damped oscillatory manner, which we could discern despite the fluctuations in the MD data.

  19. The molecular signature of AML mesenchymal stromal cells reveals candidate genes related to the leukemogenic process.

    Science.gov (United States)

    Binato, Renata; de Almeida Oliveira, Nathalia Correa; Du Rocher, Barbara; Abdelhay, Eliana

    2015-12-01

    Acute myeloid leukemia (AML) is a heterogeneous disease characterized by myeloid precursor proliferation in the bone marrow, apoptosis reduction and differentiation arrest. Although there are several studies in this field, events related to disease initiation and progression remain unknown. The malignant transformation of hematopoietic stem cells (HSC) is thought to generate leukemic stem cells, and this transformation could be related to changes in mesenchymal stromal cell (hMSC) signaling. Thus, the aim of this work was to analyze the gene expression profile of hMSC from AML patients (hMSC-AML) compared to healthy donors hMSCs (hMSC-HD). The results showed a common molecular signature for all hMSC-AML. Other assays were performed with a large number of patients and the results confirmed a molecular signature that is capable of distinguishing hMSC-AML from hMSC-HD. Moreover, CCL2 and BMP4 genes encode secreted proteins that could affect HSCs. To verify whether these proteins are differentially expressed in AML patients, ELISA was performed with plasma samples. CCL2 and BMP4 proteins are differentially expressed in AML patients, indicating changes in hMSC-AML signaling. Altogether, hMSCs-AML signaling alterations could be an important factor in the leukemic transformation process. PMID:26279521

  20. Processing of meteoritic organic materials as a possible analog of early molecular evolution in planetary environments.

    Science.gov (United States)

    Pizzarello, Sandra; Davidowski, Stephen K; Holland, Gregory P; Williams, Lynda B

    2013-09-24

    The composition of the Sutter's Mill meteorite insoluble organic material was studied both in toto by solid-state NMR spectroscopy of the powders and by gas chromatography-mass spectrometry analyses of compounds released upon their hydrothermal treatment. Results were compared with those obtained for other meteorites of diverse classifications (Murray, GRA 95229, Murchison, Orgueil, and Tagish Lake) and found to be so far unique in regard to the molecular species released. These include, in addition to O-containing aromatic compounds, complex polyether- and ester-containing alkyl molecules of prebiotic appeal and never detected in meteorites before. The Sutter's Mill fragments we analyzed had likely been altered by heat, and the hydrothermal conditions of the experiments realistically mimic early Earth settings, such as near volcanic activity or impact craters. On this basis, the data suggest a far larger availability of meteoritic organic materials for planetary environments than previously assumed and that molecular evolution on the early Earth could have benefited from accretion of carbonaceous meteorites both directly with soluble compounds and, for a more protracted time, through alteration, processing, and release from their insoluble organic materials. PMID:24019471

  1. 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.

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

    Science.gov (United States)

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

    2010-01-01

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

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

    Science.gov (United States)

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

    2010-10-01

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

  4. 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.

  5. Molecular dynamics simulations of mixed lubrication with smooth particle post-processing

    Energy Technology Data Exchange (ETDEWEB)

    Eder, S; Vernes, A; Vorlaufer, G [Austrian Center of Competence for Tribology, Viktor-Kaplan-Strasse 2, 2700 Wiener Neustadt (Austria); Betz, G [Institute of Applied Physics, Vienna University of Technology, Wiedner Hauptstrasse 8-10/134, 1040 Vienna (Austria)

    2011-05-04

    A post-processing method for molecular dynamics (MD) simulations of friction based on the smooth particle approach is proposed, allowing-among other features-the introduction and evaluation of a solid-solid contact area arising due to direct asperity interaction. In order to illustrate the feasibility of this scheme, a large number of MD calculations of lubricated nanotribological systems with various asperity geometries and carefully selected numbers of lubricant molecules were carried out and analysed. In this manner, it is shown that the friction force as a function of load agrees very well with a three-parameter friction law which, in addition to the adhesion- and the load-controlled terms, contains a load-independent offset.

  6. 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

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

    Science.gov (United States)

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

    2008-07-01

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

  8. Ionization of molecular hydrogen by proton impact. II. Two-electron processes

    International Nuclear Information System (INIS)

    Cross sections for double ionization and ionization plus excitation of H2 by high-energy protons are calculated as a function of the orientation of the H2 internuclear axis. Only the contributions of the double-collision process have been included. The ground state of H2 is described by Heitler-London-type wave functions, and the molecular orbitals for the excited states of H2+ are constructed from atomic functions. The results have been compared with the data of Edwards et al. [Phys. Rev. A 42, 1367 (1990); 44, 797 (1991); Nucl. Instrum. Methods Phys. Res. B 53, 472 (1991)] and Ezell et al. [Nucl. Instrum. Methods Phys. Res. B 56/57, 292 (1991)]. The theoretical and measured cross sections have the same magnitude for double ionization. For the excitation of the 2p?u, 2p?u, and 2s?g states, the calculated cross sections are much lower than the measured ones

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

    CERN Document Server

    Anderl, S; Forts, 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. 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...

  11. Molecular design of new P3HT derivatives: Adjusting electronic energy levels for blends with PCBM

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Eliezer Fernando [UNESP Univ Estadual Paulista, POSMAT Programa de Ps-Graduao em Cincia e Tecnologia de Materiais, Bauru, SP (Brazil); Lavarda, Francisco Carlos, E-mail: lavarda@fc.unesp.br [UNESP Univ Estadual Paulista, POSMAT Programa de Ps-Graduao em Cincia e Tecnologia de Materiais, Bauru, SP (Brazil); Faculdade de Cincias, UNESP Univ Estadual Paulista, Departamento de Fsica, Av. Eng. Luiz Edmundo Carrijo Coube, 14-01, 17033-360 Bauru, SP (Brazil)

    2014-12-15

    An intensive search is underway for new materials to make more efficient organic solar cells through improvements in thin film morphology, transport properties, and adjustments to the energy of frontier electronic levels. The use of chemical modifications capable of modifying the electronic properties of materials already known is an interesting approach, as it can, in principle, provide a more adequate adjustment of the frontier electronic levels while preserving properties such as solubility. Based on this idea, we performed a theoretical study of poly(3-hexylthiophene) (P3HT) and 13 new derivatives obtained by substitution with electron acceptor and donor groups, in order to understand how the energy levels of the frontier orbitals are modified. The results show that it is possible to deduce the modification of the electronic levels in accordance with the substituent's acceptor/donor character. We also evaluated how the substituents influence the open circuit voltage and the exciton binding energy. - Highlights: Prediction of P3HT derivatives properties for bulk-heterojunction solar cells. Correlating substituent properties with electronic levels of P3HT derivatives. Fluorinated P3HT improves open circuit voltage and stability.

  12. Molecular design of new P3HT derivatives: Adjusting electronic energy levels for blends with PCBM

    International Nuclear Information System (INIS)

    An intensive search is underway for new materials to make more efficient organic solar cells through improvements in thin film morphology, transport properties, and adjustments to the energy of frontier electronic levels. The use of chemical modifications capable of modifying the electronic properties of materials already known is an interesting approach, as it can, in principle, provide a more adequate adjustment of the frontier electronic levels while preserving properties such as solubility. Based on this idea, we performed a theoretical study of poly(3-hexylthiophene) (P3HT) and 13 new derivatives obtained by substitution with electron acceptor and donor groups, in order to understand how the energy levels of the frontier orbitals are modified. The results show that it is possible to deduce the modification of the electronic levels in accordance with the substituent's acceptor/donor character. We also evaluated how the substituents influence the open circuit voltage and the exciton binding energy. - Highlights: Prediction of P3HT derivatives properties for bulk-heterojunction solar cells. Correlating substituent properties with electronic levels of P3HT derivatives. Fluorinated P3HT improves open circuit voltage and stability

  13. Reactivity of the calcitewater-interface, from molecular scale processes to geochemical engineering

    International Nuclear Information System (INIS)

    Highlights: The current state of some aspects of calcitewater-interface chemistry is reviewed. The interface structure is characterized at a molecular scale. Experimental and theoretical studies on contaminant sorption at calcite are presented. The influence of phosphonates on calcite growth is investigated. The effect of limestone on the workability of cement suspensions is addressed. - Abstract: Surface reactions on calcite play an important role in geochemical and environmental systems, as well as many areas of industry. In this review, we present investigations of calcite that were performed in the frame of the joint research project RECAWA (reactivity of calcitewater-interfaces: molecular process understanding for technical applications). As indicated by the project title, work within the project comprised a large range of length scales. The molecular scale structure of the calcite (1 0 4)water-interface is refined based on surface diffraction data. Structural details are related to surface charging phenomena, and a simplified basic stern surface complexation model is proposed. As an example for trace metal interactions with calcite surfaces we review and present new spectroscopic and macroscopic experimental results on Selenium interactions with calcite. Results demonstrate that selenate (SeO42?) shows no significant interaction with calcite at our experimental conditions, while selenite (SeO32?) adsorbs at the calcite surface and can be incorporated into the calcite structure. Atomistic calculations are used to assess the thermodynamics of sulfate (SO42?), selenate (SeO42?), and selenite (SeO32?) partitioning in calcite and aragonite. The results show that incorporation of these oxo-anions into the calcite structure is so highly endothermic that incorporation is practically impossible at bulk equilibrium and standard conditions. This indicates that entrapment processes are involved when coprecipitation is observed experimentally. The relevance of nano-scale surface features is addressed in an investigation of calcite growth and precipitation in the presence of phosphonates, demonstrating the influence of phosphonates on the morphology of growth spirals and macroscopic growth rates. It is investigated how physical properties of limestone containing cement suspensions may influence the workability of the cement suspensions and thus the efficacy of limestone in industrial applications. The largest scale is reached in iron filtration experiments in a water-purification-pilot-plant using limestone as filter material, which appeared to be highly effective for removing iron from drinking water. Investigations presented cover a whole series of methods to study the calcitewater-interface. Many calcite related topics are addressed, demonstrating how broad the field of calcitewater-interface research is and how manifold the applications are, for which calcitewater-interface phenomena are of major relevance

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-01-15

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

  15. 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 repair and new Infra-red camera for determination of glass height in the canister are discussed. (authors)

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

    International Nuclear Information System (INIS)

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

  17. Consolidation of slow or fast but not moderately evolving genes at the level of pathways and processes.

    Science.gov (United States)

    Vinogradov, Alexander E

    2015-04-25

    Conservatism versus innovation is probably the most important dichotomy of all evolving systems. In molecular evolution the distinction between conservative (negative) selection, innovative (positive) selection and unconstrained evolution (drift) is usually ambiguous at the gene level. Only rare cases with the ratio of nonsynonymous to synonymous nucleotide substitutions above unity (dN/dS>1) are thought to be due to positive selection, whereas the lower dN/dS ratio may indicate negative selection in combination with drift. The density of the dN/dS ratio for orthologous genes forms a unimodal distribution where no particular regions can be discerned. Here it is shown that at the level of overrepresented pathways and processes the picture is strikingly different. The distribution is strongly polarized with a wide completely depressed middle part. This three-phase distribution is very robust. It is observed with various substitution models and remains at very low significance of overrepresentation (up to ptinkering' at the gene level and 'design' at the higher levels is forming. PMID:25707747

  18. GROMACS: High performance molecular simulations through multi-level parallelism from laptops to supercomputers

    Science.gov (United States)

    Abraham, Mark James; Murtola, Teemu; Schulz, Roland; Pll, Szilrd; Smith, Jeremy C.; Hess, Berk; Lindahl, Erik

    2015-09-01

    GROMACS is one of the most widely used open-source and free software codes in chemistry, used primarily for dynamical simulations of biomolecules. It provides a rich set of calculation types, preparation and analysis tools. Several advanced techniques for free-energy calculations are supported. In version 5, it reaches new performance heights, through several new and enhanced parallelization algorithms. These work on every level; SIMD registers inside cores, multithreading, heterogeneous CPU-GPU acceleration, state-of-the-art 3D domain decomposition, and ensemble-level parallelization through built-in replica exchange and the separate Copernicus framework. The latest best-in-class compressed trajectory storage format is supported.

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

    OpenAIRE

    Maestri, Matteo; Reuter, Karsten

    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) mech...

  20. 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, Andr 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.

  1. 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

  2. Processing of water level derived from water pressure data at the Time Series Station Spiekeroog

    Science.gov (United States)

    Holinde, L.; Badewien, T. H.; Freund, J. A.; Stanev, E. V.; Zielinski, O.

    2015-10-01

    The quality of water level time series data strongly varies with periods of high- and low-quality sensor data. In this paper we are presenting the processing steps which were used to generate high-quality water level data from water pressure measured at the Time Series Station (TSS) Spiekeroog. The TSS is positioned in a tidal inlet between the islands of Spiekeroog and Langeoog in the East Frisian Wadden Sea (southern North Sea). The processing steps will cover sensor drift, outlier identification, interpolation of data gaps and quality control. A central step is the removal of outliers. For this process an absolute threshold of 0.25 m 10 min-1 was selected which still keeps the water level increase and decrease during extreme events as shown during the quality control process. A second important feature of data processing is the interpolation of gappy data which is accomplished with a high certainty of generating trustworthy data. Applying these methods a 10-year data set (December 2002-December 2012) of water level information at the TSS was processed resulting in a 7-year time series (2005-2011). Supplementary data are available at doi:10.1594/PANGAEA.843740.

  3. New molecular markers for fungal phylogenetics: Two genes for species level systematics in the Sordariomycetes (Ascomycota)

    Science.gov (United States)

    Although significant progress has been made resolving deep branches of the fungal tree of life in recent works, many fungal systematists are interested in species-level questions to both define species and to assess fungal biodiversity. Fungal genome sequences are a useful resource to systematic bio...

  4. Molecular Level-Crossing and the Geometric Phase Effect from the Optical Hanle Perspective

    CERN Document Server

    Glenn, R

    2016-01-01

    Level-crossing spectroscopy involves lifting the degeneracy of an excited state and using the interference of two nearly degenerate levels to measure the excited state lifetime. Here we use the idea of interference between different pathways to study the momentum-dependent wave packet lifetime due an excited state level-crossing (conical intersection) in a molecule. Changes in population from the wave packet propagation are reflected in the detected fluorescence. We use a chirped pulse to control the wave packet momentum. Changing the chirp rate affects the transition to the lower state through the conical intersection. It also affects the interference of different pathways in the upper electronic state, due to the geometric phase acquired. Increasing the chirp rate decreases the coherence of the wave packet in the upper electronic state. This suggests that there is a finite momentum dependent lifetime of the wave packet through the level-crossing as function of chirp. We dub this lifetime the wave packet mom...

  5. 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...

  6. Two-level hierarchical fragmentation in the Orion Molecular Cloud 1 northern filament

    CERN Document Server

    Teixeira, P S; Zapata, L A; Ho, P T P

    2015-01-01

    [Abridged] We have recently reported on the collapse and fragmentation properties of the northernmost part of this structure, located ~2.4pc north of Orion KL -- the Orion Molecular Cloud 3 (OMC 3, Takahashi et al. 2013). As part of our project to study the integral-shaped filament, we analyze the fragmentation properties of the northern OMC 1 filament. This filament is a dense structure previously identified by JCMT/SCUBA submillimeter continuum and VLA ammonia observations and shown to have fragmented into clumps. We observed OMC1 n with the Submillimeter Array (SMA) at 1.3mm and report on our analysis of the continuum data. We discovered 24 new compact sources, ranging in mass from 0.1 to 2.3, in size from 400 to 1300au, and in density from 2.6 x 10^7 to 2.8 x 10^6 cm^{-3}. The masses of these sources are similar to those of the SMA protostars in OMC3, but their typical sizes and densities are lower by a factor of ten. Only 8% of the new sources have infrared counterparts, yet there are five associated CO ...

  7. Adiabatic and non-adiabatic charge pumping in a single-level molecular motor

    Science.gov (United States)

    Napitu, B. D.; Thijssen, J. M.

    2015-07-01

    We propose a design for realizing quantum charge pump based on a recent proposal for a molecular motor (Seldenthuis J S et al 2010 ACS Nano 4 6681). Our design is based on the presence of a moiety with a permanent dipole moment which can rotate, thereby modulating the couplings to metallic contacts at both ends of the molecule. Using the non-equilibrium Keldysh Greens function formalism (NEGF), we show that our design indeed generates a pump current. In the non-interacting pump, the variation of frequency from adiabatic to non-adiabatic regime, can be used to control the direction as well as the amplitude of the average current. The effect of Coulomb interaction is considered within the first- and the second- order perturbation. The numerical implementation of the scheme is quite demanding, and we develop an analytical approximation to obtain a speed-up giving results within a reasonable time. We find that the amplitude of the average pumped current can be controlled by both the driving frequency and the Coulomb interaction. The direction of of pumped current is shown to be determined by the phase difference between left and right anchoring groups.

  8. 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

  9. Physical modeling of Fermi-level effects for decanano device process simulations

    International Nuclear Information System (INIS)

    We report on a physically based Fermi-level modeling approach designed to be accurate and yet amenable to be implemented in a device-size process simulator. We use an atomistic kinetic Monte Carlo method in conjunction with a continuum treatment for carrier densities. The model includes: (i) charge reactions and electric bias according to the local Fermi-level; (ii) pairing and break-up reactions involving charged particles; (iii) clustering-related dopant deactivation; and (iv) Fermi level-dependent solubility. Degenerated statistics, band-gap narrowing, and damage-induced electrical compensation are also included. The parameters used for charged particles are in agreement with ab initio calculations and experimental results. This modeling scheme has proved to be very computationally efficient for realistic device-dimension process simulations. We present an illustrative set of simulation results for two common dopants, boron and arsenic, and discuss the potential of this approach for accurate process simulation of decanano CMOS devices

  10. Molecular-level tuning of cellular autonomy controls the collective behaviors of cell populations

    CERN Document Server

    Maire, Théo

    2016-01-01

    A rigorous understanding of how multicellular behaviors arise from the actions of single cells requires quantitative frameworks that bridge the gap between genetic circuits, the arrangement of cells in space, and population-level behaviors. Here, we provide such a framework for a ubiquitous class of multicellular systems - namely, "secrete-and-sense cells" that communicate by secreting and sensing a signaling molecule. By using formal, mathematical arguments and introducing the concept of a phenotype diagram, we show how these cells tune their degrees of autonomous and collective behavior to realize distinct single-cell and population-level phenotypes; these phenomena have biological analogs, such as quorum sensing or paracrine signaling. We also define the "entropy of population," a measurement of the number of arrangements that a population of cells can assume, and demonstrate how a decrease in the entropy of population accompanies the formation of ordered spatial patterns. Our conceptual framework ties tog...

  11. A hybrid PSO-PID approach for trajectory tracking application of a liquid level control process

    Directory of Open Access Journals (Sweden)

    Turker Tekin Erguzel

    2015-07-01

    Full Text Available Water level control is a crucial step for steam generators (SG which are widely used to control the temperature of nuclear power plants. The control process is therefore a challenging task to improve the performance of water level control system. The performance assessment is another consideration to underline. In this paper, in order to get better control of water level, the nonlinear process was first expressed in terms of a transfer function (TF, a proportional-integral-derivative (PID controller was then attached to the model. The parameters of the PID controller was finally optimized using particle swarm optimization (PSO. Simulation results indicate that the proposed approach can make an effective tracking of a given level set or reference trajectory.

  12. 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 g/mL, 32 g/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.

  13. 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.

  14. Review process of PSA Level 2 of KBR. Concept and experience

    International Nuclear Information System (INIS)

    In Germany, a periodic safety review (PSR) has to be performed every 10 years by the utility. In the past, a PSR only included a plant-specific probabilistic safety analysis (PSA) Level 1 study. For the NPP Brokdorf (KBR) PSA Level 2 project, an agreement was reached between all parties involved that the study will be performed not as a part of the PSR process, but supplementary to it. Since a revised version of the German PSA guideline has been released in 2005, these plant-specific PSAs have to include a PSA Level 2, too. This paper will focus on conclusions and findings from a ongoing parallel review process of the first full scope PSA Level 2 performed by the utility for KBR, a typical German PWR-1300. The responsible authority 'Ministerium fuer Soziales, Gesundheit, Familie, Jugend und Senioren des Landes Schleswig-Holstein (MSGF)' (Ministry of Social Affairs, Health, Family, Youth and Senior Citizens of Schleswig-Holstein) initiated this parallel review process in agreement with the utility KBR and the E.ON Kernkraft in 2006. The project will be completed soon. Such a review process allows that essential steps of the PSA will be reviewed and commented before the PSA Level 2 will be finished. So the benefit from this parallel review process is a significant enhancement of the quality and completeness of the PSA Level 2 study as the majority of the recommendations given by the review team has been taken over by the utility and the developer of the PSA, the Areva NP company. Further, a common understanding and agreement will be reached at the end between all parties involved on the major topics of the PSA Level 2 study. (orig.)

  15. 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.

  16. 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...

  17. 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 streams

  18. 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.

  19. Solution processable small molecular host materials for blue and white phosphorescence OLEDs

    Science.gov (United States)

    Lee, Yi-Ting; Chang, Yung-Ting; Chen, Chin-Ti; Chen, Chao-Tsen

    2013-09-01

    Three new solution processable small molecular host materials based on bis-[3,5-di(9H-carbazol-9-yl)phenyl] structural moiety have been developed for blue phosphorescence (FIrpic dopant) organic light-emitting diodes. Whereas N,N-bis-[3,5-di(9H-carbazol-9-yl)phenyl]methylamine (CzPAMe) has the highest solid state triplet energy gap (ET) of 2.73 eV, tetrakis-[3,3',5,5'-(9H-carbazol-9-yl)]triphenylphosphine oxide (CzPPO) and N,N-bis-[3,5-di(9H-carbazol-9-yl)phenyl]pyrimidin-2-amine (CzPAPm) are two host materials potentially being bipolar for charge transport due to the electron deficient unit of phenylphosphine oxide and pyrimidine, respectively. Due to the insufficient ET (2.56 eV) of CzPAPm, CzPPO or CzPAMe devices are significantly better than CzPAPm devices with or without 1,3-bis[(4-tert-butylphenyl)-1,3,4-oxadiazolyl]phenylene (OXD-7) co-host. Particularly, having no OXD-7 co-host and no vacuum-thermal-deposited extra electron transporting layer, single-layer devices of CzPPO surpassing CzPAMe devices reach current efficiency as high as 9.32 cd/A (or power efficiency of 4.97 lm/W), which is one of the highest of the kind. Corresponding single-layer white phosphorescence OLEDs are also fabricated with the small molecular host material demonstrated herein.

  20. Molecular and Genomic Characterization of Vibrio mimicus Isolated from a Frozen Shrimp Processing Facility in Mexico.

    Science.gov (United States)

    Guardiola-Avila, Iliana; Acedo-Felix, Evelia; Sifuentes-Romero, Itzel; Yepiz-Plascencia, Gloria; Gomez-Gil, Bruno; Noriega-Orozco, Lorena

    2016-01-01

    Vibrio mimicus is a gram-negative bacterium responsible for diseases in humans. Three strains of V. mimicus identified as V. mimicus 87, V. mimicus 92 and V. mimicus 93 were isolated from a shrimp processing facility in Guaymas, Sonora, Mexico. The strains were analyzed using several molecular techniques and according to the cluster analysis they were different, their similarities ranged between 51.3% and 71.6%. ERIC-PCR and RAPD (vmh390R) were the most discriminatory molecular techniques for the differentiation of these strains. The complete genomes of two strains (V. mimicus 87, renamed as CAIM 1882, and V. mimicus 92, renamed as CAIM 1883) were sequenced. The sizes of the genomes were 3.9 Mb in both strains, with 2.8 Mb in ChI and 1.1 Mb in ChII. A 12.7% difference was found in the proteome content (BLAST matrix). Several virulence genes were detected (e.g. capsular polysaccharide, an accessory colonization factor and genes involved in quorum-sensing) which were classified in 16 categories. Variations in the gene content between these genomes were observed, mainly in proteins and virulence genes (e.g., hemagglutinin, mobile elements and membrane proteins). According to these results, both strains were different, even when they came from the same source, giving an insight of the diversity of V. mimicus. The identification of various virulence genes, including a not previously reported V. mimicus gene (acfD) in ChI in all sequenced strains, supports the pathogenic potential of this species. Further analysis will help to fully understand their potential virulence, environmental impact and evolution. PMID:26730584

  1. Molecular and Genomic Characterization of Vibrio mimicus Isolated from a Frozen Shrimp Processing Facility in Mexico

    Science.gov (United States)

    Guardiola-Avila, Iliana; Acedo-Felix, Evelia; Sifuentes-Romero, Itzel; Yepiz-Plascencia, Gloria; Gomez-Gil, Bruno; Noriega-Orozco, Lorena

    2016-01-01

    Vibrio mimicus is a gram-negative bacterium responsible for diseases in humans. Three strains of V. mimicus identified as V. mimicus 87, V. mimicus 92 and V. mimicus 93 were isolated from a shrimp processing facility in Guaymas, Sonora, Mexico. The strains were analyzed using several molecular techniques and according to the cluster analysis they were different, their similarities ranged between 51.3% and 71.6%. ERIC-PCR and RAPD (vmh390R) were the most discriminatory molecular techniques for the differentiation of these strains. The complete genomes of two strains (V. mimicus 87, renamed as CAIM 1882, and V. mimicus 92, renamed as CAIM 1883) were sequenced. The sizes of the genomes were 3.9 Mb in both strains, with 2.8 Mb in ChI and 1.1 Mb in ChII. A 12.7% difference was found in the proteome content (BLAST matrix). Several virulence genes were detected (e.g. capsular polysaccharide, an accessory colonization factor and genes involved in quorum-sensing) which were classified in 16 categories. Variations in the gene content between these genomes were observed, mainly in proteins and virulence genes (e.g., hemagglutinin, mobile elements and membrane proteins). According to these results, both strains were different, even when they came from the same source, giving an insight of the diversity of V. mimicus. The identification of various virulence genes, including a not previously reported V. mimicus gene (acfD) in ChI in all sequenced strains, supports the pathogenic potential of this species. Further analysis will help to fully understand their potential virulence, environmental impact and evolution. PMID:26730584

  2. Advanced treatment processes for low and intermediate level radwastes in India

    International Nuclear Information System (INIS)

    Development of improved treatment processes for low and intermediate level radwastes is being pursued in India in view of the increasing environmental and regulatory concerns. Copper hexacyanoferrate loaded, macroporous anion exchange resin was developed as an effective sorbent for the removal of radiocesium from low level aqueous effluents and spent fuel storage pool water. The reverse osmosis process using cellulose acetate membranes was tested in pilot scale as an alternative treatment process for low level aqueous wastes. A treatment scheme for alkaline intermediate level aqueous wastes based on the selective uptake of radiocesium by a resorcinol-formaldehyde polycondensate resin was developed in the laboratory and found satisfactory in trials with the alkaline waste of a reprocessing plant. Synthetic zeolites are being tested for fixation of activity released in solution in wet oxidative destruction of spent ion exchange resin, arising from reactors and other nuclear facilities. All these processes are being critically evaluated for possible application in the treatment of low and intermediate level radwastes in India

  3. 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.

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

    Science.gov (United States)

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

    2012-09-12

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

  5. 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

  6. Solidification of low-level radioactive liquid waste using a cement-silicate process

    International Nuclear Information System (INIS)

    Extensive use has been made of silicate and Portland cement for the solidification of industrial waste and recently this method has been successfully used to solidify a variety of low level radioactive wastes. The types of wastes processed to date include fuel fabrication sludges, power reactor waste, decontamination solution, and university laboratory waste. The cement-silicate process produces a stable solid with a minimal increase in volume and the chemicals are relatively inexpensive and readily available. The method is adaptable to either batch or continuous processing and the equipment is simple. The solid has leaching characteristics similar to or better than plain Portland cement mixtures and the leaching can be further reduced by the use of ion-exchange additives. The cement-silicate process has been used to solidify waste containing high levels of boric acid, oils, and organic solvents. The experience of handling the various types of liquid waste with a cement-silicate system is described

  7. Low Striatal Glutamate Levels Underlie Cognitive Decline in the Elderly: Evidence from In Vivo Molecular Spectroscopy

    OpenAIRE

    Zahr, Natalie M.; Mayer, Dirk; Pfefferbaum, Adolf; Sullivan, Edith V.

    2008-01-01

    Glutamate (Glu), the principal excitatory neurotransmitter of prefrontal cortical efferents, potentially mediates higher order cognitive processes, and its altered availability may underlie mechanisms of age-related decline in frontally based functions. Although animal studies support a role for Glu in age-related cognitive deterioration, human studies, which require magnetic resonance spectroscopy for in vivo measurement of this neurotransmitter, have been impeded because of the similarity o...

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

    Czech Academy of Sciences Publication Activity Database

    Figueroa-Gerstenmaier, S.; Francova, M.; Kowalski, M.; Lsal, 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 ostatn: NRCC(CA) OGP 1041 Institutional research plan: CEZ:AV0Z40720504 Source of funding: V - in verejn zdroje Keywords : alternative refrigerants * joule-thomson expansion * adiabatic process Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.506, year: 2007

  9. 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

  10. 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...

  11. Processes of direct democracy on the federal level in Brazil: An inventory and a research outlook

    OpenAIRE

    Rauschenbach, Rolf

    2012-01-01

    Problem addressed: Brazil is well known for its participatory budget. However, little information is available to the international academic community when it comes to the Brazilian practice of processes of direct democracy. Result of this study: This paper provides a full account of the Brazilian processes of direct democracy on the federal level, including their historical and legal context. It draws a preliminary conclusion and formulates a research outlook. Method applied: Desk-research.

  12. 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...

  13. The Effect of Sea Level Changes on Geomorphological Processes Along the Coast.

    OpenAIRE

    Kapule, D.E.

    1991-01-01

    Geomorphological processes at work on the coastal landforms are influenced by a number of environmental factors. The coastal area is a scene of interaction between different spheres of the earth like hydrosphere, lithosphere, atmosphere, biosphere and technosphere. Each of these spheres has its own influence on the development of the coastal landforms. This paper tries to explain the effect of the sea level change on geomorphological processes taking into account the influence imparted by eac...

  14. Predicting the Effects of Common Levels of Variability on Flow Processing Systems

    OpenAIRE

    David STOCKTON; Khalil, Riham; Fresco, John Anthony

    2008-01-01

    Abstract The implementation of flow processing is essential to the successful application of lean manufacturing practices since it provides the infrastructure for both pull production to take place and the focussed elimination of waste. With the adoption of lean practices into a broader range of production environments there is an increasing need for flow processing to operate under a wider range of conditions particularly with respect to the sources and levels of variability that ...

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

    OpenAIRE

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

    2013-01-01

    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%), and 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 pos...

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

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

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

  17. Operational nanometric gas counters for nuclear risk assessment at the bio-molecular level

    International Nuclear Information System (INIS)

    The practical implementation of the system for protection of persons against exposure to ionizing radiation requires that appropriate radiation detectors be designed to produce an output signal which can be related to the risk of deleterious biological effect. At present, conventional dosimeters are used to assess the risk either by measurement of macroscopic quantities such as energy imparted, modified by appropriately evaluated weighting factors, or by microdosimeters which can measure simultaneously the dose and a quality factor obtained from the stochastic distribution of dose, e.g. the lineal energy of microdosimetry. Both types of dosimeter now have recognised limitations which inhibit their accuracy for damage assessment. This is because in practice their radiation response functions could not take account of advances in our understanding of the radiobiological damage mechanisms which involve 'target' sizes of sub-micron dimensions, less than 30 nm, and probably as small as molecular dimensions of 2 nm e.g. a segment of the DNA. If radiation detectors can be designed to simulate the response of relevant biological material by allowing for the dimensions and multiplicity of the radiosensitive target sizes, then there are good prospects of achieving significant improvements in dosimetry instrumentation which, in principle, could lead to direct measurement of risk in unknown radiation fields without the need for arbitrary modifying factors or knowledge of the radiation type. In this context of the foregoing, a prototype of a nanodosimetric counter has been built and used to measure the ionization cluster size distributions for energetic ?-particles in tissue equivalent gases with a spatial resolution of 1 nm. The total and double differential electron scattering cross-sections of the components of the tissue equivalent gases have been measured absolutely for electron energies up to 5 keV and for scattering angles from 30 deg to 120 deg by applying a new method. These cross-sections are implemented in a Monte Carlo code which is developed for realistic simulation of the stochastic nature of the radiation interactions on the scale of the DNA size. The agreement of the experimental data with the results of the Monte Carlo simulation is satisfactory and encouraging (author)

  18. 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 3πg electronic state of N2. The experimental result of this work is 13 + 1 μs. To measure the lifetime of B 3πg (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 3πg --- A 3ΣΩ+ 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)

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

    Directory of Open Access Journals (Sweden)

    Charles Romel Yez 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 Bogot 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.

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

    DEFF Research Database (Denmark)

    Michelsen, Axel Gottlieb; Stoustrup, Jakob

    2010-01-01

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

  1. Nested Hierarchical Dirichlet Processes for Multi-Level Non-Parametric Admixture Modeling

    OpenAIRE

    Tekumalla, Lavanya Sita; Agrawal, Priyanka; Bhattacharya, Indrajit

    2015-01-01

    Dirichlet Process(DP) is a Bayesian non-parametric prior for infinite mixture modeling, where the number of mixture components grows with the number of data items. The Hierarchical Dirichlet Process (HDP), is an extension of DP for grouped data, often used for non-parametric topic modeling, where each group is a mixture over shared mixture densities. The Nested Dirichlet Process (nDP), on the other hand, is an extension of the DP for learning group level distributions from data, simultaneousl...

  2. 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; Sørensen, Christian Hjort; Kilian, Mogens

    2013-01-01

    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...... 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...... 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...

  3. 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.

  4. Socio-Psychological Factors Affecting Participatory Planning Processes At Interactional Level

    Directory of Open Access Journals (Sweden)

    Neslihan KULZ

    2014-02-01

    Full Text Available Today, it is widely accepted that communities need to collaborate when making decisions on behalf of the individual, society and the environment. Hence, planners engaged in participatory initiatives need to understand how best to design and carry out a participatory planning process. In order to answer this question, all factors affecting participatory processes need to be determined, since only then can steps be taken to design and execute the best participatory process for each stakeholder in every unique context. By focusing particularly on the factors affecting participatory processes at interactional level, this study aims to determine the socio-psychological dimensions of participatory planning processes, the aim being to bring to light some hitherto unexplained factors involved and thus help to improve these processes. Based on previous discussions in participation literature, the ultimate aim of this study is to provide subsequent researchers and those involved in participatory planning practices with a framework on the socio-psychological dimensions, namely communication, power, attribution, relationships and persuasion, of participatory processes at interactional level.

  5. Pedagogical Technology of Improving the Students' Viability Levels in the Process of Mastering Foreign Language

    Science.gov (United States)

    Dmitrienko, Nadezhda; Ershova, Svetlana; Konovalenko, Tatiana; Kutsova, Elvira; Yurina, Elena

    2015-01-01

    The article points out that the process of mastering foreign language stimulates students' personal, professional and cultural growth, improving linguistic, communicative competences and viability levels. A proposed pedagogical technology of modeling different communicative situations has a serious synergetic potential for students' self organized

  6. 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

  7. 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; Bargholz, Kim; Hovgaard, Jens

    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...

  8. 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.

  9. 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

  10. Dogs, cats, and kin: a molecular species-level phylogeny of Carnivora.

    Science.gov (United States)

    Agnarsson, Ingi; Kuntner, Matjaz; May-Collado, Laura J

    2010-03-01

    Phylogenies underpin comparative biology as high-utility tools to test evolutionary and biogeographic hypotheses, inform on conservation strategies, and reveal the age and evolutionary histories of traits and lineages. As tools, most powerful are those phylogenies that contain all, or nearly all, of the taxa of a given group. Despite their obvious utility, such phylogenies, other than summary 'supertrees', are currently lacking for most mammalian orders, including the order Carnivora. Carnivora consists of about 270 extant species including most of the world's large terrestrial predators (e.g., the big cats, wolves, bears), as well as many of man's favorite wild (panda, cheetah, tiger) and domesticated animals (dog, cat). Distributed globally, carnivores are highly diverse ecologically, having occupied all major habitat types on the planet and being diverse in traits such as sociality, communication, body/brain size, and foraging ecology. Thus, numerous studies continue to address comparative questions within the order, highlighting the need for a detailed species-level phylogeny. Here we present a phylogeny of Carnivora that increases taxon sampling density from 28% in the most detailed primary-data study to date, to 82% containing 243 taxa (222 extant species, 17 subspecies). In addition to extant species, we sampled four extinct species: American cheetah, saber-toothed cat, cave bear and the giant short-faced bear. Bayesian analysis of cytochrome b sequences data-mined from GenBank results in a phylogenetic hypothesis that is largely congruent with prior studies based on fewer taxa but more characters. We find support for the monophyly of Carnivora, its major division into Caniformia and Feliformia, and for all but one family within the order. The only exception is the placement of the kinkajou outside Procyonidae, however, prior studies have already cast doubt on its family placement. In contrast, at the subfamily and genus level, our results indicate numerous problems with current classification. Our results also propose new, controversial hypotheses, such as the possible placement of the red panda (Ailuridae) sister to canids (Canidae). Our results confirm previous findings suggesting that the dog was domesticated from the Eurasian wolf (Canis lupus lupus) and are congruent with the Near East domestication of the cat. In sum, this study presents the most detailed species-level phylogeny of Carnivora to date and a much needed tool for comparative studies of carnivoran species. To demonstrate one such use, we perform a phylogenetic analysis of evolutionary distinctiveness (EDGE), which can be used to help establish conservation priorities. According with those criteria, and under one of the many possible sets of parameters, the highest priority Carnivora species for conservation of evolutionary diversity include: monk seals, giant and red panda, giant otter, otter civet, Owston's palm civet, sea otter, Liberian mongoose, spectacled bear, walrus, binturong, and the fossa. PMID:19900567

  11. 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, Franoise; Francez, Andr-Jean; Mah, Stphane; Bormans, Myriam; Lagadeuc, Yvan; Coue, 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, organismenvironment interactions, functional diversity, ecosystem processes, evolution and Earth history. Thu...

  12. 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)

  13. New treatment facility for low level process effluents at the Savannah River site

    International Nuclear Information System (INIS)

    A new facility, the F/H Effluent Treatment Facility (F/H ETF) is under construction at the Savannah River site. It will decontaminate process effluents containing low levels of radionuclides and hazardous chemicals prior to discharge to a surface stream. These effluents, which are currently discharged to seepage basins, originate in the chemical separations and high-level radioactive waste processing areas, known as F-Area and H-Area. The new facility will allow closure of the basins in order to meet the provisions of the Resource Conservation and Recovery Act by November 1988. A high degree of reliability is expected from this design as a result of extensive process development work that has been conducted at the Savannah River Laboratory. This work has included both bench scale testing of individual unit operations and pilot scale testing of an integrated facility, 150 to 285 L/min (40 to 75 gpm), that contains the major operations

  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 pretestposttest 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 36-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. Does level of processing affect the transition from unconscious to conscious perception?

    Science.gov (United States)

    Anzulewicz, Anna; Asanowicz, Dariusz; Windey, Bert; Paulewicz, Borys?aw; Wierzcho?, Micha?; Cleeremans, Axel

    2015-11-01

    Recently, Windey, Gevers, and Cleeremans (2013) proposed a level of processing (LoP) hypothesis claiming that the transition from unconscious to conscious perception is influenced by the level of processing imposed by task requirements. Here, we carried out two experiments to test the LoP hypothesis. In both, participants were asked to classify briefly presented pairs of letters as same or different, based either on the letters' physical features (a low-level task), or on a semantic rule (a high-level task). Stimulus awareness was measured by means of the four-point Perceptual Awareness Scale (PAS). The results showed that low or moderate stimulus visibility was reported more frequently in the low-level task than in the high-level task, suggesting that the transition from unconscious to conscious perception is more gradual in the former than in the latter. Therefore, although alternative interpretations remain possible, the results of the present study fully support the LoP hypothesis. PMID:26057402

  16. Unravelling Doping Effects on PEDOT at the Molecular Level: From Geometry to Thermoelectric Transport Properties.

    Science.gov (United States)

    Shi, Wen; Zhao, Tianqi; Xi, Jinyang; Wang, Dong; Shuai, Zhigang

    2015-10-14

    Tuning carrier concentration via chemical doping is the most successful strategy to optimize the thermoelectric figure of merit. Nevertheless, how the dopants affect charge transport is not completely understood. Here we unravel the doping effects by explicitly including the scattering of charge carriers with dopants on thermoelectric properties of poly(3,4-ethylenedioxythiophene), PEDOT, which is a p-type thermoelectric material with the highest figure of merit reported. We corroborate that the PEDOT exhibits a distinct transition from the aromatic to quinoid-like structure of backbone, and a semiconductor-to-metal transition with an increase in the level of doping. We identify a close-to-unity charge transfer from PEDOT to the dopant, and find that the ionized impurity scattering dominates over the acoustic phonon scattering in the doped PEDOT. By incorporating both scattering mechanisms, the doped PEDOT exhibits mobility, Seebeck coefficient and power factors in very good agreement with the experimental data, and the lightly doped PEDOT exhibits thermoelectric properties superior to the heavily doped one. We reveal that the thermoelectric transport is highly anisotropic in ordered crystals, and suggest to utilize large power factors in the direction of polymer backbone and low lattice thermal conductivity in the stacking and lamellar directions, which is viable in chain-oriented amorphous nanofibers. PMID:26406937

  17. Fortuitous description of hemoglobin Hope in a high-level Tunisian athlete: molecular diagnosis and origin.

    Science.gov (United States)

    Bibi, Amina; Touhemi, Imed; Sahli, Chaima; Siala, Hajer; Bartagi, Zakia; Koubaa, Donia; Le Gallais, Daniel; Fattoum, Slaheddine; Messaoud, Taieb

    2012-01-01

    In this study we report the fortuitous description of hemoglobin (Hb) Hope in a Tunisian athlete. This Hb is one of hemoglobin variants that show a lower stability and oxygen affinity that is beneficial to tissue oxygen delivery. Hb Hope was isolated by automated high performance liquid chromatography and was unequivocally found to be Hb Hope using DNA-based methods: polymerase chain reaction, denaturing gradient gel electrophoresis, direct DNA sequencing. Restriction haplotype showed that this Hb was supported by the Mediterranean haplotype I. Hb Hope was identified at first in a black African-American family and later in several other black and non black ethnic groups. All these descriptions raise the question of the Hb Hope origin. Recently, Hb Hope was reported in Thai in association with the same Mediterranean haplotype I. This favors that Tunisian and Thai Hb Hope would share a common Mediterranean origin, thus suggesting the possibility of a Mediterranean gene flow. On another hand, the observation of Hb Hope in a high level athlete would suggest a selection pressure of this Hb variant due to higher physical aptitude. PMID:22565177

  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. Beyond Fullerenes: Designing Alternative Molecular Electron Acceptors for Solution-Processable Bulk Heterojunction Organic Photovoltaics.

    Science.gov (United States)

    Sauv, Genevive; Fernando, Roshan

    2015-09-17

    Organic photovoltaics (OPVs) are promising candidates for providing a low cost, widespread energy source by converting sunlight into electricity. Solution-processable active layers have predominantly consisted of a conjugated polymer donor blended with a fullerene derivative as the acceptor. Although fullerene derivatives have been the acceptor of choice, they have drawbacks such as weak visible light absorption and poor energy tuning that limit overall efficiencies. This has recently fueled new research to explore alternative acceptors that would overcome those limitations. During this exploration, one question arises: what are the important design principles for developing nonfullerene acceptors? It is generally accepted that acceptors should have high electron affinity, electron mobility, and absorption coefficient in the visible and near-IR region of the spectra. In this Perspective, we argue that alternative molecular acceptors, when blended with a conjugated polymer donor, should also have large nonplanar structures to promote nanoscale phase separation, charge separation and charge transport in blend films. Additionally, new material design should address the low dielectric constant of organic semiconductors that have so far limited their widespread application. PMID:26722869

  20. Ab initio molecular dynamics simulation of the energy-relaxation process of the protonated water dimer.

    Science.gov (United States)

    Yamauchi, Yusuke; Ozawa, Shiho; Nakai, Hiromi

    2007-03-22

    Relaxation processes of the energy-rich protonated water dimer H+(H2O)2 were investigated by the ab initio molecular dynamics (AIMD) method. At first, the energy-rich H+(H2O)2 was reproduced by simulating a collision reaction between the protonated water monomer H3O+ and H2O. Next it was collided with N2 in order to observe the effects of intramolecular vibration redistribution and intermolecular energy transfer. Forty-eight AIMD simulations of the collision of H+(H2O)2 with N2 were performed by changing the initial orientation and the time interval between two collisions. It was revealed that the amount of energy transferred from H+(H2O)2 to N2 decreased the longer the time interval. The relationship between the intermolecular energy transfer and the vibrational states was examined with the use of an energy-transfer spectrogram (ETS), which is an analysis technique combining energy density analysis and short-time Fourier transform. The ETS demonstrates a characteristic vibrational mode for the energy transfer, which corresponds to the stretching of the hydrogen bond between H+(H2O)2 and N2 in an active complex. PMID:17388294

  1. Online monitoring of molecular processes in a plasma air purifying system.

    Science.gov (United States)

    Schmid, Stefan; Meier, Lukas; Berchtold, Christian; Zenobi, Renato

    2012-04-01

    Plasma air purifying systems present an interesting alternative to filters for purifying air. In this study, molecular processes in a commercially available ac driven plasma air purifier were studied in detail. This air purifier is supposed to reduce all air contaminants to small nontoxic molecules (e.g., H(2)O and CO(2)). However, degradation mechanisms are not yet fully understood. In this study, we investigated the exhaust of the plasma air purifier to determine which degradation products are formed. An interface was designed and constructed to allow the direct coupling of the plasma air purifier's exhaust to a mass spectrometer. The compounds studied, primary and secondary amines, were introduced at a concentration of 1 ppmV. Contrary to our expectations, polymerization instead of degradation was observed. The higher the ac voltage applied (max. 9.0 kV) to the plasma air purifier, the higher the mass of the oligomer distribution. Side chain oxidation products as well as oligomers could be observed for all compounds tested. Starting with amines of low mass (m/z air purifier. Detailed analysis of the observed mass spectra as well as experiments with deuterated dibutylamine helped to unravel the mechanism taking place in the plasma air purifier. Nitrate anions generated in the plasma air purifier (presumably from N(2)) are proposed to form ionic clusters with protonated amines. PMID:22420672

  2. Molecular mechanism of the inhibition effect of Lipoxin A4 on corneal dissolving pathology process

    Directory of Open Access Journals (Sweden)

    Hong-Yan Zhou

    2013-02-01

    Full Text Available AIM: Excessive dissolve of corneal tissue induced by MMPs which were activated by cytokins and chemokines will lead to corneal ulcer. The molecular mechanism of Lipoxin A4 (LXA4 on corneal collagen degradation in three dimensions was investigated.METHODS:Rabbit corneal fibroblasts were harvested and suspended in serum-free MEM. Type I collagen, DMEM, collagen reconstitution buffer and corneal fibroblast suspension were mixed on ice. The resultant mixture solidified in an incubator, after which test reagents and plasminogen was overlaid and the cultures were returned to the incubator. The supernatants from collagen gel incubations were collected and the amount of hydroxyproline in the hydrolysate was measured. Immunoblot analysis of MMP-1, -3 and TMMP-1,-2 was performed. MMP-2,-9 was detected by the method of Gelatin zymography. Cytotoxicity assay was measured.RESULTS:LXA4 inhibited corneal collagen degradation in a dose and time manner. LXA4 inhibited the IL-1? induced increases in the pro-MMP-1, -2, -3, -9 and active MMP-1, -2, -3, -9 in a concentration dependent manner. LXA4 could also inhibit the IL-1? induced increases in TIMP-1, -2.CONCLUSION: As a potent anti-inflammation reagent, LXA4 can inhibit corneal collagen degradation induced by IL-1? in corneal fibroblasts thus inhibiting corneal dissolving pathology process.

  3. A molecular dynamics simulation study of dynamic process and mesoscopic structure in liquid mixture systems

    Science.gov (United States)

    Yang, Peng

    The focus of this dissertation is the Molecular Dynamics (MD) simulation study of two different systems. In thefirst system, we study the dynamic process of graphene exfoliation, particularly graphene dispersion using ionic surfactants (Chapter 2). In the second system, we investigate the mesoscopic structure of binary solute/ionic liquid (IL) mixtures through the comparison between simulations and corresponding experiments (Chapter 3 and 4). In the graphene exfoliation study, we consider two separation mechanisms: changing the interlayer distance and sliding away the relative distance of two single-layer graphene sheets. By calculating the energy barrier as a function of separation (interlayer or sliding-away) distance and performing sodium dodecyl sulfate (SDS) structure analysis around graphene surface in SDS surfactant/water + bilayer graphene mixture systems, we find that the sliding-away mechanism is the dominant, feasible separation process. In this process, the SDS-graphene interaction gradually replaces the graphene-graphene Van der Waals (VdW) interaction, and decreases the energy barrier until almost zero at critical SDS concentration. In solute/IL study, we investigate nonpolar (CS2) and dipolar (CH 3CN) solute/IL mixture systems. MD simulation shows that at low concentrations, IL is nanosegregated into an ionic network and nonpolar domain. It is also found that CS2 molecules tend to be localized into the nonpolar domain, while CH3CN interacts with nonpolar domain as well as with the charged head groups in the ionic network because of its amphiphilicity. At high concentrations, CH3CN molecules eventually disrupt the nanostructural organization. This dissertation is organized in four chapters: (1) introduction to graphene, ionic liquids and the methodology of MD; (2) MD simulation of graphene exfoliation; (3) Nanostructural organization in acetonitrile/IL mixtures; (4) Nanostructural organization in carbon disulfide/IL mixtures; (5) Conclusions. Results of MD simulations of liquid mixture systems car-ried out in this research explain observed experiments and show the details of nanostructural organizations in small solute molecules/IL mixture. Additionally, the research successfully reveals the correct mechanism of graphene exfoliation process in liquid solution. (This will be summarized in Chapter 5.) The research presented in this dissertation enhances our understanding of the microscopic behaviors in complex liquid systems as well as the theoretical method to explore them.

  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. The Role of Atomic and Molecular Processes in Magnetic Fusion Plasmas

    International Nuclear Information System (INIS)

    Plasma edge physics (plasmas with temperatures in the 1 to 100 eV range, near solid surfaces) has become a key issue in controlled nuclear fusion research. As for the physics of the fully ionized hot plasma core, appropriate dimensionless parameters have been identified: present fusion research acts like wind-channel experiments on downsized models, with respect to future fusion reactors. This is not longer possible for the plasma edge region due to dominant effects from atomic and surface processes. Integrated computational models comprising the physics of the plasma flow near boundaries, the atomic and molecular processes and the particle-surface interactions are the only tool to evaluate present experimental results (LHD, JT60, Tore Supra, JET,...) with respect to their relevance for future fusion power experiments (ITER) or a reactor.In particular proton and electron collisions with the hydrogenic molecules H2, O2, T2, DT, and their ions, play a key role in cooling and attenuating the magnetically confined plasma, before it hits exposed target surfaces. The surface released molecules travel in a bath of electrons and hydrogenic ions, with plasma temperatures (in the relevant region) in the 1 to 20 eV range, and typical (plasma) scale lengths are in the 1 to 10 cm range.Sample calculations with current fusion plasma edge codes, as e.g. used by the international design team for the ITER prototypical fusion reactor, applied to the tokamak with the highest divertor collisionality today (Alcator-C-Mod), are used to demonstrate these issues

  6. In-situ NMR study of molecular and ionic processes inside carbon nanopores

    Science.gov (United States)

    Luo, Zhixiang

    Interactions of simple ions with water and interfaces play critical roles in many electrochemical and biological processes. They are especially significant in nanoconfined regions and have a profound impact in many applications, for instance nanofluidics and supercapacitors. This dissertation employs a nuclear magnetic resonance (NMR) technique to study their influence on the ionic processes inside carbon nanopores. To characterize the carbon micropore structure, a convenient NMR method is established by taking a 1H magic angle spinning (MAS) spectrum of the adsorbed water. A density functional theory (DFT) computation of the nucleus-independent chemical shift (NICS) yields a quantitative relationship between the NICS values and the micropore sizes. The carbon micropore size and distribution are derived from the chemical shift and the spectrum lineshape. For aqueous electrolytes inside uncharged carbon nanopores, the measurement of ion concentrations reveals a substantial electroneutrality breakdown. The specific ion effects and ion-ion correlations are shown to play crucial roles in determining the degree of electroneutrality breakdown. The importance of those interactions is further revealed by the asymmetric and nonlinear responses of ion concentrations to the charging of the confining carbon walls. Such information is obtained with a carbon supercapacitor built into the NMR probe. The NMR observations are validated by a numerical calculation of the ion distribution in the nanopores using the generalized Poisson-Boltzmann (PB) equation, demonstrating that the nonelectrostatic interfacial interactions can indeed dominate the electrostatic interactions and lead to the breakdown of electroneutrality inside nanoconfined regions. Interfacial ion hydration is an essential part of the specific ion effects. Using in-situ 23Na and 19F NMR on carbon supercapacitors with different carbon pore sizes, I provide a molecular-scale understanding of the permeation and dehydration of ions in voltage-gated carbon nanopores.

  7. 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.

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

    DEFF Research Database (Denmark)

    Jensen, Anders; Fag-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. Molecular mapping to species level of the tonsillar crypt microbiota associated with health and recurrent tonsillitis.

    Science.gov (United States)

    Jensen, Anders; Fag-Olsen, Helena; Srensen, Christian Hjort; Kilian, Mogens

    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. PMID:23437130

  10. Molecular-level characterization of probucol nanocrystal in water by in situ solid-state NMR spectroscopy.

    Science.gov (United States)

    Zhang, Junying; Higashi, Kenjirou; Limwikrant, Waree; Moribe, Kunikazu; Yamamoto, Keiji

    2012-02-28

    The molecular state of colloidal probucol nanoparticles with additives was evaluated by (13)C in situ solid-state NMR spectroscopy. The nanoparticles were obtained by dispersing a ternary co-ground mixture of probucol/polyvinylpyrrolidon (PVP)/sodium dodecyl sulfate (SDS) in water. Their mean particle size was found to be approximately 150 nm by dynamic light scattering and cryogenic-scanning electron microscopy measurements. The results of the (13)C in situ solid-state NMR spectroscopy showed that probucol existed in the crystalline state (form I) in water. (13)C liquid-state NMR results indicated that PVP and SDS interacted with probucol in water. Their broad signals suggested that the surface interaction of the probucol nanocrystal with PVP and SDS stabilized the suspension. In addition, a freeze-dried sample of the suspension was studied by (13)C solid-state NMR and powder X-ray diffraction experiments, which confirmed the presence of the probucol nanocrystals. The combination of the in situ solid-state, solid-state, and liquid-state NMR measurement results provided molecular-level insights about the role of intermolecular interactions in the design of nanoformulations. PMID:22138607

  11. Linking molecular level chemistry to macroscopic combustion behavior for nano-energetic materials with halogen containing oxides

    Science.gov (United States)

    Farley, Cory W.; Pantoya, Michelle L.; Losada, Martin; Chaudhuri, Santanu

    2013-08-01

    Coupling molecular scale reaction kinetics with macroscopic combustion behavior is critical to understanding the influences of intermediate chemistry on energy propagation, yet bridging this multi-scale gap is challenging. This study integrates ab initio quantum chemical calculations and condensed phase density functional theory to elucidate factors contributing to experimentally measured high flame speeds (i.e., >900 m/s) associated with halogen based energetic composites, such as aluminum (Al) and iodine pentoxide (I2O5). Experiments show a direct correlation between apparent activation energy and flame speed suggesting that flame speed is directly influenced by chemical kinetics. Toward this end, the first principle simulations resolve key exothermic surface and intermediate chemistries contributing toward the kinetics that promote high flame speeds. Linking molecular level exothermicity to macroscopic experimental investigations provides insight into the unique role of the alumina oxide shell passivating aluminum particles. In the case of Al reacting with I2O5, the alumina shell promotes exothermic surface chemistries that reduce activation energy and increase flame speed. This finding is in contrast to Al reaction with metal oxides that show the alumina shell does not participate exothermically in the reaction.

  12. Comb-linked, cavity ring-down spectroscopy for measurements of molecular transition frequencies at the kHz-level.

    Science.gov (United States)

    Truong, G-W; Long, D A; Cygan, A; Lisak, D; van Zee, R D; Hodges, J T

    2013-03-01

    We present a low uncertainty measurement technique for determining molecular transition frequencies. This approach is complementary to sub-Doppler saturation spectroscopies and is expected to enable new frequency measurements for a wide variety of molecular species with uncertainties at the kHz-level. The technique involves measurements of Doppler broadened lines using cavity ring-down spectroscopy whereby the probe laser is actively locked to the ring-down cavity and the spectrum frequencies are linked directly to an optical frequency comb that is referenced to an atomic frequency standard. As a demonstration we have measured the transition frequency of the (30012) ? (00001) P14e line of CO2 near 1.57 ?m with a combined standard uncertainty of ~9 kHz. This technique exhibits exceptional promise for measurements of transition frequencies and pressure shifting parameters of many weak absorbers, and indicates the potential for substantially improved measurements when compared to those obtained with conventional spectroscopic methods. PMID:23485285

  13. 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.Tcnicas de encapsulamento, como "spray-drying" e formao de complexos por incluso com ciclodextrinas, vm sendo avaliadas para viabilizar a adio de carotenides em sistemas hidroflicos e aumentar a sua estabilidade durante o processamento e estocagem. Portanto, o objetivo do presente trabalho foi obter licopeno encapsulado na forma de p, utilizando processos de "spray-drying" ou de incluso molecular com beta -ciclodextrina (CD seguido de liofilizao. A eficincia do encapsulamento utilizando "spray-drying" variou de 94 a 96% e o rendimento mdio foi de 51%, com as microcpsulas apresentando indentaes superficiais, porm sem falhas ou aberturas na superfcie. A formao de complexo licopeno- beta -CD ocorreu apenas quando utilizada razo molar de 1:4, e estruturas irregulares de diferentes tamanhos que eventualmente formaram agregados, similares s da beta -CD, foram observadas aps liofilizao. O licopeno no complexado neste processo ficou em torno de 50%. A pureza do licopeno (% rea do all-trans-licopeno aumentou de 96,4 para 98,1% aps o encapsulamento, enquanto que a pureza do licopeno diminuiu de 97,7 para 91,3% aps complexao e liofilizao. Os dois processos de secagem resultaram em ps rosa claro, secos e com bom fluxo.

  14. 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 Tcnicas de encapsulamento, como "spray-drying" e formao de complexos por incluso com ciclodextrinas, vm sendo avaliadas para viabilizar a adio de carotenides em sistemas hidroflicos e aumentar a sua estabilidade durante o processamento e estocagem. Portanto, o objetivo do presente trabalho [...] foi obter licopeno encapsulado na forma de p, utilizando processos de "spray-drying" ou de incluso molecular com beta -ciclodextrina (CD) seguido de liofilizao. A eficincia do encapsulamento utilizando "spray-drying" variou de 94 a 96% e o rendimento mdio foi de 51%, com as microcpsulas apresentando indentaes superficiais, porm sem falhas ou aberturas na superfcie. A formao de complexo licopeno- beta -CD ocorreu apenas quando utilizada razo molar de 1:4, e estruturas irregulares de diferentes tamanhos que eventualmente formaram agregados, similares s da beta -CD, foram observadas aps liofilizao. O licopeno no complexado neste processo ficou em torno de 50%. A pureza do licopeno (% rea do all-trans-licopeno) aumentou de 96,4 para 98,1% aps o encapsulamento, enquanto que a pureza do licopeno diminuiu de 97,7 para 91,3% aps complexao e liofilizao. Os dois processos de secagem resultaram em ps 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.

  15. 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

  16. Site-scale process integration and utility optimization with multi-level energy requirement definition

    International Nuclear Information System (INIS)

    Highlights: • A methodology for energy efficiency of large-scale chemical plants is developed. • A multi-level data extraction for energy requirement definition is introduced. • The practice of total site integration with the combination of levels is shown. • The suitable utilities are integrated and optimized for different proposals. • A Pareto analysis is performed to find the optimum combination of levels. - Abstract: This study presents a methodology based on process integration techniques to improve the energy efficiency of a large-scale chemical plant. The key to the approach is to represent the energy requirements with different heat transfer interfaces. Considering difficulties of data extraction for a large-scale plant, a multi-level data extraction scheme is introduced based on different heat transfer interfaces and includes five levels of growing complexity: black-box, grey-box, white-box, simple-model and detailed-model analysis. A combination of these levels instead of a single definition for the energy requirement has been applied on an industrial case study. Different steps of the approach are explained in detail and their potential are highlighted. The Single Process Integration (SPI) and Total Site Integration (TSI) has been performed and revealed that a higher potential of heat recovery could be driven through the TSI. The optimized site utility integration together with heat recovery improvement scenarios have considerably increased the energy saving potential in our case study. A multi-objective optimization has also been performed to find the optimum combination of units with different energy requirement levels. In conclusion, results from our case study have indicated that using a combination of different energy requirement levels will reduce the required modification of the actual site configuration

  17. Decision Processes During Development of Molecular Biomarkers for Gonadal Phenotypic Sex

    Science.gov (United States)

    Molecular biomarkers for determination of gonadal phenotypic sex in the Japanese medaka (Oryzias latipes), will serve as a case study. The medaka has unique features that aid in the development of appropriate molecular biomarkers of gonad phenotype, a) genetic sex can be determin...

  18. Teaching the Process of Molecular Phylogeny and Systematics: A Multi-Part Inquiry-Based Exercise

    Science.gov (United States)

    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

  19. Neighborhood-level social processes and substantiated cases of child maltreatment.

    Science.gov (United States)

    Molnar, Beth E; Goerge, Robert M; Gilsanz, Paola; Hill, Andrea; Subramanian, S V; Holton, John K; Duncan, Dustin T; Beatriz, Elizabeth D; Beardslee, William R

    2016-01-01

    Child maltreatment is a preventable public health problem. Research has demonstrated that neighborhood structural factors (e.g. poverty, crime) can influence the proportion of a neighborhood's children who are victims of maltreatment. A newer strategy is the identification of potentially modifiable social processes at the neighborhood level that can also influence maltreatment. Toward this end, this study examines neighborhood-level data (maltreatment cases substantiated by Illinois' child protection agency, 1995-2005, social processes measured by the Project on Human Development in Chicago Neighborhoods, U.S. Census data, proportions of neighborhoods on public assistance, and crime data) that were linked across clusters of contiguous, relatively homogenous Chicago, IL census tracts with respect to racial/ethnic and socioeconomic composition. Our analysis-an ecological-level, repeated cross-sectional design utilizing random-intercept logit models-with a sensitivity analysis using spatial models to control for spatial autocorrelation-revealed consistent associations between neighborhood social processes and maltreatment. Neighborhoods higher in collective efficacy, intergenerational closure, and social networks, and lower in disorder had lower proportions of neglect, physical abuse, and sexual abuse substantiated cases, controlling for differences in structural factors. Higher collective efficacy and social network size also predicted a lower proportion of substance-exposed infants. This research indicates that strategies to mobilize neighborhood-level protective factors may decrease child maltreatment more effectively than individual and family-focused efforts alone. PMID:26684963

  20. Two-years' experience in processing high-level waste at West Valley

    International Nuclear Information System (INIS)

    The U.S. Department of Energy is charged with the solidification of high-level liquid waste remaining from nuclear fuel reprocessing activities that were conducted at West Valley, New York, between 1966 and 1972. Before the high-level waste (HLW) can be vitrified, it must be volume reduced by removing the low-level waste (LLW) fraction. During the past 2 yr, West Valley has successfully processed approximately half of the 600,000 gal of high-level radioactive waste stored in an underground storage tank. Processing involves the removal of the 137Cs from the HLW by ion exchange, evaporation to concentrate the effluent to a predetermined salt concentration, and finally cementation in 71-gal square drums. This produces a class C LLW form that meets the waste form criteria specified in the U.S. Nuclear Regulatory Commission's (NRC's) 1983 Branch Technical Position. The waste produced is stored onsite awaiting final disposition. This paper describes the very successful experience gained over the past 2 yr in processing HLW at West Valley, major operational problems and resolutions thereof, results of the long-term destructive evaluation program of actual product drums, and the product characteristics

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

    Directory of Open Access Journals (Sweden)

    P.K. Bhaba

    2007-01-01

    Full Text Available Level control is very important for the successful operation of most chemical and biochemical industries since it is through the proper control of flows and levels that the desired production rates and inventories can be achieved. The aim of this study was the development and real time implementation of a Wiener Model based PI Controller (WMPIC for a conical tank level process. The conical tank level process exhibits severe static non-linear behavior and dynamic characteristics. Here, a WMPIC structure was developed by the way of compensating the process static non-linearity. Tuning rules suggested by PadmaSree-Srinivas-Chidambaram (2004 and Ziegler-Nichols (1942 were considered here for designing the controller. The real time implementation results of wiener model based PI controller were compared with those obtained using a conventional Linear PI Controller (LPIC. The performance of these controllers was analyzed in terms of Integral Square Error (ISE criterion. In addition to this, the robustness of the controllers was also analyzed.

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

    Science.gov (United States)

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

    Level control is very important for the successful operation of most chemical and biochemical industries since it is through the proper control of flows and levels that the desired production rates and inventories can be achieved. The aim of this study was the development and real time implementation of a Wiener Model based PI Controller (WMPIC) for a conical tank level process. The conical tank level process exhibits severe static non-linear behavior and dynamic characteristics. Here, a WMPIC structure was developed by the way of compensating the process static non-linearity. Tuning rules suggested by PadmaSree-Srinivas-Chidambaram (2004) and Ziegler-Nichols (1942) were considered here for designing the controller. The real time implementation results of wiener model based PI controller were compared with those obtained using a conventional Linear PI Controller (LPIC). The performance of these controllers was analyzed in terms of Integral Square Error (ISE) criterion. In addition to this, the robustness of the controllers was also analyzed.

  3. Evaluation of an Improved Branch-Site Likelihood Method for Detecting Positive Selection at the Molecular Level

    DEFF Research Database (Denmark)

    Zhang, Jianzhi; Nielsen, Rasmus; Yang, Ziheng

    2005-01-01

    Detecting positive Darwinian selection at the DNA sequence level has been a subject of considerable interest. However, positive selection is difficult to detect because it often operates episodically on a few amino acid sites, and the signal may be masked by negative selection. Several methods have...... been developed to test positive selection that acts on given branches (branch methods) or on a subset of sites (site methods). Recently, Yang, Z., and R. Nielsen (2002. Codon-substitution models for detecting molecular adaptation at individual sites along specific lineages. Mol. Biol. Evol. 19......:908-917) developed likelihood ratio tests (LRTs) based on branch-site models to detect positive selection that affects a small number of sites along prespecified lineages. However, computer simulations suggested that the tests were sensitive to the model assumptions and were unable to distinguish between relaxation...

  4. Comparison of surface vacuum ultraviolet emissions with resonance level number densities. II. Rare-gas plasmas and Ar-molecular gas mixtures

    International Nuclear Information System (INIS)

    Vacuum ultraviolet (VUV) emissions from excited plasma species can play a variety of roles in processing plasmas, including damaging the surface properties of materials used in semiconductor processing. Depending on their wavelength, VUV photons can easily transmit thin upper dielectric layers and affect the electrical characteristics of the devices. Despite their importance, measuring VUV fluxes is complicated by the fact that few materials transmit at VUV wavelengths, and both detectors and windows are easily damaged by plasma exposure. The authors have previously reported on measuring VUV fluxes in pure argon plasmas by monitoring the concentrations of Ar(3p54s) resonance atoms that produce the VUV emissions using noninvasive optical emission spectroscopy in the visible/near-infrared wavelength range [Boffard et al., J. Vac. Sci. Technol., A 32, 021304 (2014)]. Here, the authors extend this technique to other rare-gases (Ne, Kr, and Xe) and argon-molecular gas plasmas (Ar/H2, Ar/O2, and Ar/N2). Results of a model for VUV emissions that couples radiation trapping and the measured rare-gas resonance level densities are compared to measurements made with both a calibrated VUV photodiode and a sodium salicylate fluorescence detection scheme. In these more complicated gas mixtures, VUV emissions from a variety of sources beyond the principal resonance levels of the rare gases are found to contribute to the total VUV flux

  5. Comparison of surface vacuum ultraviolet emissions with resonance level number densities. II. Rare-gas plasmas and Ar-molecular gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Boffard, John B., E-mail: jboffard@wisc.edu; Lin, Chun C. [Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States); Wang, Shicong; Wendt, Amy E. [Department of Electrical and Computer Engineering, University of Wisconsin, Madison, Wisconsin 53706 (United States); Culver, Cody [Materials Science Program, University of Wisconsin, Madison, Wisconsin 53706 (United States); Radovanov, Svetlana; Persing, Harold [Applied Materials Inc., Gloucester, Massachusetts 01939 (United States)

    2015-03-15

    Vacuum ultraviolet (VUV) emissions from excited plasma species can play a variety of roles in processing plasmas, including damaging the surface properties of materials used in semiconductor processing. Depending on their wavelength, VUV photons can easily transmit thin upper dielectric layers and affect the electrical characteristics of the devices. Despite their importance, measuring VUV fluxes is complicated by the fact that few materials transmit at VUV wavelengths, and both detectors and windows are easily damaged by plasma exposure. The authors have previously reported on measuring VUV fluxes in pure argon plasmas by monitoring the concentrations of Ar(3p{sup 5}4s) resonance atoms that produce the VUV emissions using noninvasive optical emission spectroscopy in the visible/near-infrared wavelength range [Boffard et al., J. Vac. Sci. Technol., A 32, 021304 (2014)]. Here, the authors extend this technique to other rare-gases (Ne, Kr, and Xe) and argon-molecular gas plasmas (Ar/H{sub 2}, Ar/O{sub 2}, and Ar/N{sub 2}). Results of a model for VUV emissions that couples radiation trapping and the measured rare-gas resonance level densities are compared to measurements made with both a calibrated VUV photodiode and a sodium salicylate fluorescence detection scheme. In these more complicated gas mixtures, VUV emissions from a variety of sources beyond the principal resonance levels of the rare gases are found to contribute to the total VUV flux.

  6. 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.

  7. 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.

  8. 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.

  9. Convergent Evolution of Hemoglobin Function in High-Altitude Andean Waterfowl Involves Limited Parallelism at the Molecular Sequence Level.

    Science.gov (United States)

    Natarajan, Chandrasekhar; Projecto-Garcia, Joana; Moriyama, Hideaki; Weber, Roy E; Muoz-Fuentes, Violeta; Green, Andy J; Kopuchian, Cecilia; Tubaro, Pablo L; Alza, Luis; Bulgarella, Mariana; Smith, Matthew M; Wilson, Robert E; Fago, Angela; McCracken, Kevin G; Storz, Jay F

    2015-12-01

    A fundamental question in evolutionary genetics concerns the extent to which adaptive phenotypic convergence is attributable to convergent or parallel changes at the molecular sequence level. Here we report a comparative analysis of hemoglobin (Hb) function in eight phylogenetically replicated pairs of high- and low-altitude waterfowl taxa to test for convergence in the oxygenation properties of Hb, and to assess the extent to which convergence in biochemical phenotype is attributable to repeated amino acid replacements. Functional experiments on native Hb variants and protein engineering experiments based on site-directed mutagenesis revealed the phenotypic effects of specific amino acid replacements that were responsible for convergent increases in Hb-O2 affinity in multiple high-altitude taxa. In six of the eight taxon pairs, high-altitude taxa evolved derived increases in Hb-O2 affinity that were caused by a combination of unique replacements, parallel replacements (involving identical-by-state variants with independent mutational origins in different lineages), and collateral replacements (involving shared, identical-by-descent variants derived via introgressive hybridization). In genome scans of nucleotide differentiation involving high- and low-altitude populations of three separate species, function-altering amino acid polymorphisms in the globin genes emerged as highly significant outliers, providing independent evidence for adaptive divergence in Hb function. The experimental results demonstrate that convergent changes in protein function can occur through multiple historical paths, and can involve multiple possible mutations. Most cases of convergence in Hb function did not involve parallel substitutions and most parallel substitutions did not affect Hb-O2 affinity, indicating that the repeatability of phenotypic evolution does not require parallelism at the molecular level. PMID:26637114

  10. 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.

  11. Region based route planning - Multi-abstraction route planning based on intermediate level vision processing

    Science.gov (United States)

    Doshi, Rajkumar S.; Lam, Raymond; White, James E.

    1989-01-01

    Intermediate and high level processing operations are performed on vision data for the organization of images into more meaningful, higher-level topological representations by means of a region-based route planner (RBRP). The RBRP operates in terrain scenarios where some or most of the terrain is occluded, proceeding without a priori maps on the basis of two-dimensional representations and gradient-and-roughness information. Route planning is accomplished by three successive abstractions and yields a detailed point-by-point path by searching only within the boundaries of relatively small regions.

  12. Aging of theory of mind: the influence of educational level and cognitive processing.

    Science.gov (United States)

    Li, Xiaoming; Wang, Kai; Wang, Fan; Tao, Qian; Xie, Yu; Cheng, Qi

    2013-01-01

    Previous studies of theory of mind (ToM) in old age have provided mixed results. We predicted that educational level and cognitive processing are two factors influencing the pattern of the aging of ToM. To test this hypothesis, a younger group who received higher education (mean age 20.46 years), an older group with an education level equal to that of the young group (mean age 76.29 years), and an older group with less education (mean age 73.52 years) were recruited. ToM tasks included the following tests: the second-order false-belief task, the faux-pas task, the eyes test, and tests of fundamental aspects of cognitive function that included two background tests (memory span and processing speed) and three subcomponents of executive function (inhibition, updating, and shifting). We found that the younger group and the older group with equally high education outperformed the older group with less education in false-belief and faux-pas tasks. However, there was no significant difference between the two former groups. The three groups of participants performed equivalently in the eyes test as well as in control tasks (false-belief control question, faux-pas control question, faux-pas control story, and Eyes Test control task). The younger group outperformed the other two groups in the cognitive processing tasks. Mediation analyses showed that difficulties in inhibition, memory span, and processing speed mediated the age differences in false-belief reasoning. Also, the variables of inhibition, updating, memory span, and processing speed mediated age-related variance in faux-pas. Discussion focused on the links between ToM aging, educational level, and cognitive processing. Supported by Chinese National Natural Science Foundation (number: 30870766) and Anhui Province Natural Science Foundation (number: 11040606M166). PMID:22515730

  13. Molecular-level insight into unusual low pressure CO2 affinity in pillared metal-organic frameworks.

    Science.gov (United States)

    Burtch, Nicholas C; Jasuja, Himanshu; Dubbeldam, David; Walton, Krista S

    2013-05-15

    Fundamental insight into how low pressure adsorption properties are affected by chemical functionalization is critical to the development of next-generation porous materials for postcombustion CO2 capture. In this work, we present a systematic approach to understanding low pressure CO2 affinity in isostructural metal-organic frameworks (MOFs) using molecular simulations and apply it to obtain quantitative, molecular-level insight into interesting experimental low pressure adsorption trends in a series of pillared MOFs. Our experimental results show that increasing the number of nonpolar functional groups on the benzene dicarboxylate (BDC) linker in the pillared DMOF-1 [Zn2(BDC)2(DABCO)] structure is an effective way to tune the CO2 Henry's coefficient in this isostructural series. These findings are contrary to the common scenario where polar functional groups induce the greatest increase in low pressure affinity through polarization of the CO2 molecule. Instead, MOFs in this isostructural series containing nitro, hydroxyl, fluorine, chlorine, and bromine functional groups result in little increase to the low pressure CO2 affinity. Strong agreement between simulated and experimental Henry's coefficient values is obtained from simulations on representative structures, and a powerful yet simple approach involving the analysis of the simulated heats of adsorption, adsorbate density distributions, and minimum energy 0 K binding sites is presented to elucidate the intermolecular interactions governing these interesting trends. Through a combined experimental and simulation approach, we demonstrate how subtle, structure-specific differences in CO2 affinity induced by functionalization can be understood at the molecular-level through classical simulations. This work also illustrates how structure-property relationships resulting from chemical functionalization can be very specific to the topology and electrostatic environment in the structure of interest. Given the excellent agreement between experiments and simulation, predicted CO2 selectivities over N2, CH4, and CO are also investigated to demonstrate that methyl groups also provide the greatest increase in CO2 selectivity relative to the other functional groups. These results indicate that methyl ligand functionalization may be a promising approach for creating both water stable and CO2 selective variations of other MOFs for various industrial applications. PMID:23635306

  14. Supportless electrochemical sensor based on molecularly imprinted polymer modified nanoporous microrod for determination of dopamine at trace level.

    Science.gov (United States)

    Li, Yingchun; Song, Han; Zhang, Lu; Zuo, Peng; Ye, Bang-Ce; Yao, Jun; Chen, Wen

    2016-04-15

    In this work, we developed a novel freestanding metallic microrod as working electrode for highly sensitive and selective electrochemical detection of trace dopamine (DA). The electrode was facilely fabricated via first dealloying smooth Au-Ag alloy microrod (AMR) into nanoporous Au-Ag alloy microrod (NPAMR) and further modifying with electro-polymerized molecularly imprinted polymer (MIP). Influencing factors during electro-polymerization process including pH value and molar ratio of monomer to template molecule were optimized. Under the optimal conditions, a linear range from 210(-13) to 210(-8)M for measuring DA was obtained with an ultralow detection limit of 7.6310(-14)M (S/N=3). In addition, the MIP-modified electrode (MIP/NPAMR) was successfully employed to test DA in serum and brain samples. PMID:26630285

  15. A risk governance approach for high-level waste in Belgium: A process appraisal

    Energy Technology Data Exchange (ETDEWEB)

    Laes, Erik (Flemish Inst. for Technological Research (VITO)/Univ. of Antwerp, Div. Transition Energy and Environment, Mol (Belgium)), e-mail: erik.laes@vito.be; Eggermont, Gilbert (Free Univ. of Brussels (VUB), Brussels (Belgium)); Bombaerts, Gunter ((Belgium))

    2010-09-15

    The Belgian nuclear waste management organisation (NIRAS-ONDRAF) has recently started up a public debate on the strategic waste management options for the intermediate- and high-level radioactive waste (cat. B and C waste). This public debate takes place in the context of a (mandatory) strategic environmental impact assessment (SEA) procedure. The paper proposes a critical investigation of four interrelated aspects of this procedure from the point of view of 'good governance': assessment of the remaining uncertainties, guardianship of the democratic process, the organisation of expertise and the interpretation of transgenerational ethics and distributive justice in the new crisis context of globalization and failure of electricity liberalisation. We argue that - in spite of the overall soundness of the geological disposal option - many uncertainties remain: a new technical concept needs to be demonstrated and international financial management needs to be organised. On the process side we argue that although NIRAS-ONDRAF can take up a role as initiator of a public participation process, it can hardly act as a guardian of this process. The debate must be lifted above the local level, opened up to new actors with an active role of the safety authorities and guarded by a non-involved organisation. A condition for success is the creation of critical awareness and the capacity to manage controversy in future with critical expertise. Referring to the RISCOM model for transparent risk communication, we suggest some improvements to the process that is currently taking place

  16. A risk governance approach for high-level waste in Belgium: A process appraisal

    International Nuclear Information System (INIS)

    The Belgian nuclear waste management organisation (NIRAS-ONDRAF) has recently started up a public debate on the strategic waste management options for the intermediate- and high-level radioactive waste (cat. B and C waste). This public debate takes place in the context of a (mandatory) strategic environmental impact assessment (SEA) procedure. The paper proposes a critical investigation of four interrelated aspects of this procedure from the point of view of 'good governance': assessment of the remaining uncertainties, guardianship of the democratic process, the organisation of expertise and the interpretation of transgenerational ethics and distributive justice in the new crisis context of globalization and failure of electricity liberalisation. We argue that - in spite of the overall soundness of the geological disposal option - many uncertainties remain: a new technical concept needs to be demonstrated and international financial management needs to be organised. On the process side we argue that although NIRAS-ONDRAF can take up a role as initiator of a public participation process, it can hardly act as a guardian of this process. The debate must be lifted above the local level, opened up to new actors with an active role of the safety authorities and guarded by a non-involved organisation. A condition for success is the creation of critical awareness and the capacity to manage controversy in future with critical expertise. Referring to the RISCOM model for transparent risk communication, we suggest some improvements to the process that is currently taking place

  17. 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.

  18. An analytical hierarchy process for decision making of high-level-waste management

    International Nuclear Information System (INIS)

    To prove the existence value of nuclear technology for the world of post cold war, demonstration of safe rad-waste disposal is essential. High-level-waste (HLW) certainly is the key issue to be resolved. To assist a rational and persuasive process on various disposal options, an Analytical Hierarchy Process (AHP) for the decision making of HLW management is presented. The basic theory and rationale are discussed, and applications are shown to illustrate the usefulness of the AHP. The authors wish that the AHP can provide a better direction for the current doomed situations of Taiwan nuclear industry, and to exchange with other countries for sharing experiences on the HLW management

  19. Simulations of light induced processes in water based on ab initio path integrals molecular dynamics. II. Photoionization

    Science.gov (United States)

    Svoboda, Ond?ej; On?k, Milan; Slav?ek, Petr

    2011-10-01

    We have applied ab initio based reflection principle to simulate photoelectron spectra of small water clusters, ranging from monomer to octamer. The role of quantum and thermal effects on the structure of the water photoelectron spectra is discussed within the ab initio path integral molecular dynamics (PIMD) framework. We have used the PIMD method with up to 40 beads to sample the ground state quantum distribution at temperature T = 180 K. We have thoroughly tested the performance of various density functionals (B3LYP, BHandHLYP, M06HF, BNL, LC-?PBE, and CAM-B3LYP) for the ionization process description. The benchmarking based on a comparison of simulated photoelectron spectra to experimental data and high level equation-of-motion ionization potential coupled clusters with singles and doubles calculations has singled out the BHandHLYP and LC-?PBE functionals as the most reliable ones for simulations of light induced processes in water. The good performance of the density functional theory functionals to model the water photoelectron spectra also reflects their ability to reliably describe open shell excited states. The width of the photoelectron spectrum converges quickly with the cluster size as it is controlled by specific interactions of local character. The peak position is, on the other hand, defined by long-range non-specific solvent effects; it therefore only slowly converges to the corresponding bulk value. We are able to reproduce the experimental valence photoelectron spectrum of liquid water within the combined model of the water octamer embedded in a polarizable dielectric continuum. We demonstrate that including the long-range polarization and the state-specific treatment of the solvent response are needed for a reliable liquid water ionization description.

  20. 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 and population demography. (author)