WorldWideScience

Sample records for biomedicinethrough structured organization

  1. The National Center for Biomedical Ontology: Advancing Biomedicinethrough Structured Organization of Scientific Knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, Daniel L.; Lewis, Suzanna E.; Mungall, Chris J.; Misra,Sima; Westerfield, Monte; Ashburner, Michael; Sim, Ida; Chute,Christopher G.; Solbrig, Harold; Storey, Margaret-Anne; Smith, Barry; Day-Richter, John; Noy, Natalya F.; Musen, Mark A.

    2006-01-23

    The National Center for Biomedical Ontology (http://bioontology.org) is a consortium that comprises leading informaticians, biologists, clinicians, and ontologists funded by the NIH Roadmap to develop innovative technology and methods that allow scientists to record, manage, and disseminate biomedical information and knowledge in machine-processable form. The goals of the Center are: (1) to help unify the divergent and isolated efforts in ontology development by promoting high quality open-source, standards-based tools to create, manage, and use ontologies, (2) to create new software tools so that scientists can use ontologies to annotate and analyze biomedical data, (3) to provide a national resource for the ongoing evaluation, integration, and evolution of biomedical ontologies and associated tools and theories in the context of driving biomedical projects (DBPs), and (4) to disseminate the tools and resources of the Center and to identify, evaluate, and communicate best practices of ontology development to the biomedical community. The Center is working toward these objectives by providing tools to develop ontologies and to annotate experimental data, and by developing resources to integrate and relate existing ontologies as well as by creating repositories of biomedical data that are annotated using those ontologies. The Center is providing training workshops in ontology design, development, and usage, and is also pursuing research in ontology evaluation, quality, and use of ontologies to promote scientific discovery. Through the research activities within the Center, collaborations with the DBPs, and interactions with the biomedical community, our goal is to help scientists to work more effectively in the e-science paradigm, enhancing experiment design, experiment execution, data analysis, information synthesis, hypothesis generation and testing, and understand human disease.

  2. Structural aspects of agent organizations

    NARCIS (Netherlands)

    D. Grossi; F. Dignum

    2009-01-01

    In this chapter we investigate how organizations can be represented as graphs endowed with formal semantics. We distinguish different dimensions of organizations. Each of these dimensions leads to a different structure in the organizational graph. By giving the graphs a formal semantics in Descripti

  3. Managing mechanistic and organic structure in health care organizations.

    Science.gov (United States)

    Olden, Peter C

    2012-01-01

    Managers at all levels in a health care organization must organize work to achieve the organization's mission and goals. This requires managers to decide the organization structure, which involves dividing the work among jobs and departments and then coordinating them all toward the common purpose. Organization structure, which is reflected in an organization chart, may range on a continuum from very mechanistic to very organic. Managers must decide how mechanistic versus how organic to make the entire organization and each of its departments. To do this, managers should carefully consider 5 factors for the organization and for each individual department: external environment, goals, work production, size, and culture. Some factors may push toward more mechanistic structure, whereas others may push in the opposite direction toward more organic structure. Practical advice can help managers at all levels design appropriate structure for their departments and organization.

  4. Gender Structure and Spatial Organization

    Directory of Open Access Journals (Sweden)

    Minoosh Sadoughianzadeh

    2013-11-01

    Full Text Available As a contribution to the widespread debate on the “gender reading” of the “built environment,” this article aims to situate the subject in a new context, the Iranian society. To depict the subject, two distinct traditional architectures of the region, associated with their respective socio-spatial organizations, have been comparatively explored: the “Introvert” and “Extrovert.” These two almost ageless “Introvert” and “Extrovert” architectures, evolved through centuries in different geographical parts of the country, are spatial patterns aptly illustrating how the “gender structure” of each social organization has contributed to the formation of the relevant “physical space” and, further, how the specific “gender relationships” are pertinently structured within each one of the two types of the spaces. Based on a systematic approach and through concentration on the macro-socio-spatial organization, this article is to explore the gender/space associated variations within either of the social systems they belong to. This perspective is particularly instrumental in pinpointing the Introvert and Extrovert architectures in the context of their social organizations and carefully scrutinizing “gender” and “space” categories as systematically integrated variables.

  5. 16 CFR 0.9 - Organization structure.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Organization structure. 0.9 Section 0.9 Commercial Practices FEDERAL TRADE COMMISSION ORGANIZATION, PROCEDURES AND RULES OF PRACTICE ORGANIZATION § 0.9 Organization structure. The Federal Trade Commission comprises the following principal...

  6. The Design of Project Management Structural Organization

    OpenAIRE

    Dumitru Constantinescu; Cristian Etegan

    2007-01-01

    The relationships organization-suppliers-customers have recently known major changes in the structure of services and have made the organization develop its managerial and professional competencies in order to do projects. The qualified organization is the most trust-worthy in the process of doing a project. The participation of an organization in doing projects depends on a multitude of factors. Out of these factors, the structural organization comes forth, as it represents the variable with...

  7. Polymer Structure--Organic Aspects (Definitions).

    Science.gov (United States)

    Carraher, Charles E., Jr.; Seymour, Raymond B.

    1988-01-01

    Lists alphabetically the definitions of key organic-based terms used in characterizing the structure of polymers. Includes several common polymers, some of their uses and their respective structures. (CW)

  8. Structure and Structure-activity Relationship of Functional Organic Molecules

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    @@ Research theme The group is made up of junior scientists from the State Key Laboratory of Elemento-organic Chemistry, Nankai University.The scientists focus their studis on the structure and structure-activity relationship of functional organic molecules not only because it has been the basis of their research, but also because the functional study of organic compounds is now a major scientific issue for organic chemists around the world.

  9. Minerals with metal-organic framework structures

    Science.gov (United States)

    Huskić, Igor; Pekov, Igor V.; Krivovichev, Sergey V.; Friščić, Tomislav

    2016-01-01

    Metal-organic frameworks (MOFs) are an increasingly important family of advanced materials based on open, nanometer-scale metal-organic architectures, whose design and synthesis are based on the directed assembly of carefully designed subunits. We now demonstrate an unexpected link between mineralogy and MOF chemistry by discovering that the rare organic minerals stepanovite and zhemchuzhnikovite exhibit structures found in well-established magnetic and proton-conducting metal oxalate MOFs. Structures of stepanovite and zhemchuzhnikovite, exhibiting almost nanometer-wide and guest-filled apertures and channels, respectively, change the perspective of MOFs as exclusively artificial materials and represent, so far, unique examples of open framework architectures in organic minerals.

  10. Getting from Organ- to Part- Structure

    DEFF Research Database (Denmark)

    Andreasen, Mogens Myrup; Mortensen, Niels Henrik

    1997-01-01

    The paper gives definitions of organ and part and elaborate on the relations between organ, parts and production methods. The importance of the law of superimposed structures on part design is illustrated and a domain- and view concept is developed.The paper is a collective of overhead...

  11. Minerals with metal-organic framework structures

    Science.gov (United States)

    Huskić, Igor; Pekov, Igor V.; Krivovichev, Sergey V.; Friščić, Tomislav

    2016-01-01

    Metal-organic frameworks (MOFs) are an increasingly important family of advanced materials based on open, nanometer-scale metal-organic architectures, whose design and synthesis are based on the directed assembly of carefully designed subunits. We now demonstrate an unexpected link between mineralogy and MOF chemistry by discovering that the rare organic minerals stepanovite and zhemchuzhnikovite exhibit structures found in well-established magnetic and proton-conducting metal oxalate MOFs. Structures of stepanovite and zhemchuzhnikovite, exhibiting almost nanometer-wide and guest-filled apertures and channels, respectively, change the perspective of MOFs as exclusively artificial materials and represent, so far, unique examples of open framework architectures in organic minerals. PMID:27532051

  12. Unit 051 - Information Organization and Data Structure

    OpenAIRE

    055, CC in GIScience; Yeung, Albert K.

    2000-01-01

    This unit presents an overview of the terminology and concepts pertaining to information organization and data structure in the context of information science and management. The aim is to provide a general but articulate introduction to the principles and methods of information organization, with special reference to geographic information, that serves as a prerequisite for more advanced studies of data models and database in subsequent units.

  13. Growth of pseudomorphic structures through organic epitaxy

    International Nuclear Information System (INIS)

    The control of molecular orientation in thin solid film phases of organic semiconductors is a basic factor for the exploitation of their physical properties for optoelectronic devices. We compare structural and optical properties of thin films of the organic semiconductor α-quarterthiophene grown by molecular beam epitaxy on different organic substrates. We show how epitactic interactions, characteristic of the surface of organic crystals, can drive the orientation of the crystalline overlayer and the selection of specific polymorphs and new pseudomorphic phases. We identify a key role in this phenomenon played by the marked groove-like corrugations present in some organic crystal surfaces. Since different polymorphs possess rather different performance in terms of, e.g., charge carrier mobility, this strategy is demonstrated to allow for the growth of oriented phases with enhanced physical properties, while keeping the substrate at room temperature. These results provide useful guidelines for the design of technological substrates for organic epitaxy and they substantiate the adoption of an organic epitaxy approach for the fabrication of optoelectronic devices based on thin films of organic semiconductors.

  14. Band structure engineering in organic semiconductors

    Science.gov (United States)

    Schwarze, Martin; Tress, Wolfgang; Beyer, Beatrice; Gao, Feng; Scholz, Reinhard; Poelking, Carl; Ortstein, Katrin; Günther, Alrun A.; Kasemann, Daniel; Andrienko, Denis; Leo, Karl

    2016-06-01

    A key breakthrough in modern electronics was the introduction of band structure engineering, the design of almost arbitrary electronic potential structures by alloying different semiconductors to continuously tune the band gap and band-edge energies. Implementation of this approach in organic semiconductors has been hindered by strong localization of the electronic states in these materials. We show that the influence of so far largely ignored long-range Coulomb interactions provides a workaround. Photoelectron spectroscopy confirms that the ionization energies of crystalline organic semiconductors can be continuously tuned over a wide range by blending them with their halogenated derivatives. Correspondingly, the photovoltaic gap and open-circuit voltage of organic solar cells can be continuously tuned by the blending ratio of these donors.

  15. Band structure engineering in organic semiconductors.

    Science.gov (United States)

    Schwarze, Martin; Tress, Wolfgang; Beyer, Beatrice; Gao, Feng; Scholz, Reinhard; Poelking, Carl; Ortstein, Katrin; Günther, Alrun A; Kasemann, Daniel; Andrienko, Denis; Leo, Karl

    2016-06-17

    A key breakthrough in modern electronics was the introduction of band structure engineering, the design of almost arbitrary electronic potential structures by alloying different semiconductors to continuously tune the band gap and band-edge energies. Implementation of this approach in organic semiconductors has been hindered by strong localization of the electronic states in these materials. We show that the influence of so far largely ignored long-range Coulomb interactions provides a workaround. Photoelectron spectroscopy confirms that the ionization energies of crystalline organic semiconductors can be continuously tuned over a wide range by blending them with their halogenated derivatives. Correspondingly, the photovoltaic gap and open-circuit voltage of organic solar cells can be continuously tuned by the blending ratio of these donors. PMID:27313043

  16. Advanced Structural Characterization of Organic Thin Films

    DEFF Research Database (Denmark)

    Gu, Yun

    In this thesis, the structural characterizations of three organic film systems are described. Several X-ray based techniques have been utilized for the characterizations for different research goals. The structures of N,N',N-trioctyltriazatriangulenium (Oct3-TATA+) salts have been investigated...... by optical, surface and X-ray method. We describe the production of Langmuir-Blodgett film and how the absorption spectroscopy is a powerful tool to identify layer of monomer and dimer. X-ray refelctometry has been applied as a method for the study of the multilayer film and interface structure. A separation...... of small molecule and polymer layers is indicated by Flory- Huggins theory for the triisopropylsilylethynl pentacene (TIPS-PEN) and polystyrene blend films. In order to investigate the phase separated layers in the ink-jet printed films, we propose a method to measure diraction Bragg peaks by X...

  17. Virtuous organization: A structural equation modeling approach

    Directory of Open Access Journals (Sweden)

    Majid Zamahani

    2013-02-01

    Full Text Available For years, the idea of virtue was unfavorable among researchers and virtues were traditionally considered as culture-specific, relativistic and they were supposed to be associated with social conservatism, religious or moral dogmatism, and scientific irrelevance. Virtue and virtuousness have been recently considered seriously among organizational researchers. The proposed study of this paper examines the relationships between leadership, organizational culture, human resource, structure and processes, care for community and virtuous organization. Structural equation modeling is employed to investigate the effects of each variable on other components. The data used in this study consists of questionnaire responses from employees in Payam e Noor University in Yazd province. A total of 250 questionnaires were sent out and a total of 211 valid responses were received. Our results have revealed that all the five variables have positive and significant impacts on virtuous organization. Among the five variables, organizational culture has the most direct impact (0.80 and human resource has the most total impact (0.844 on virtuous organization.

  18. Tolerance and lymphoid organ structure and function

    Directory of Open Access Journals (Sweden)

    Bryna Elizabeth Burrell

    2011-12-01

    Full Text Available This issue of Frontiers in Immunologic Tolerance explores barriers to tolerance from a variety of views of cells, molecules, and processes of the immune system. Our laboratory has spent over a decade focused on the migration of the cells of the immune system, and dissecting the signals that determine how and where effector and suppressive regulatory T cells traffic from one site to another in order to reject or protect allografts. These studies have led us to a greater appreciation of the anatomic structure of the immune system, and the realization that the path taken by lymphocytes during the course of the immune response to implanted organs determines the final outcome. In particular, the structures, microanatomic domains, and the cells and molecules that lymphocytes encounter during their transit through blood, tissues, lymphatics, and secondary lymphoid organs are powerful determinants for whether tolerance is achieved. Thus, the understanding of complex cellular and molecular processes of tolerance will not come from 96-well plate immunology, but from an integrated understanding of the temporal and spatial changes that occur during the response to the allograft. The study of the precise positioning and movement of cells in lymphoid organs has been difficult since it is hard to visualize cells within their 3-dimensional setting; instead techniques have tended to be dominated by 2-dimensional renderings, although advanced confocal and 2-photon systems are changing this view. It is difficult to precisely modify key molecules and events in lymphoid organs, so that existing knockouts, transgenics, inhibitors, and activators have global and pleiotropic effects, rather than precise anatomically restricted influences. Lastly, there are no well-defined postal codes or tracking systems for leukocytes, so that while we can usually track cells from point A to point B, it is exponentially more difficult or even impossible to track them to point C and

  19. Structural analysis of hierarchically organized zeolites

    Science.gov (United States)

    Mitchell, Sharon; Pinar, Ana B.; Kenvin, Jeffrey; Crivelli, Paolo; Kärger, Jörg; Pérez-Ramírez, Javier

    2015-10-01

    Advances in materials synthesis bring about many opportunities for technological applications, but are often accompanied by unprecedented complexity. This is clearly illustrated by the case of hierarchically organized zeolite catalysts, a class of crystalline microporous solids that has been revolutionized by the engineering of multilevel pore architectures, which combine unique chemical functionality with efficient molecular transport. Three key attributes, the crystal, the pore and the active site structure, can be expected to dominate the design process. This review examines the adequacy of the palette of techniques applied to characterize these distinguishing features and their catalytic impact.

  20. Organic light emitting diodes with structured electrodes

    Science.gov (United States)

    Mao, Samuel S.; Liu, Gao; Johnson, Stephen G.

    2012-12-04

    A cathode that contain nanostructures that extend into the organic layer of an OLED has been described. The cathode can have an array of nanotubes or a layer of nanoclusters extending out from its surface. In another arrangement, the cathode is patterned and etched to form protruding nanostructures using a standard lithographic process. Various methods for fabricating these structures are provided, all of which are compatible with large-scale manufacturing. OLEDs made with these novel electrodes have greatly enhanced electron injection, have good environmental stability.

  1. Integral Design workshops: organization, structure and testing

    Directory of Open Access Journals (Sweden)

    Wim Zeiler

    2010-08-01

    Full Text Available The purpose of this paper is to achieve an understanding of design activities in the context of building design. The starting point is an overview of design research and design methodology. From the insights gained by this analysis of design in this specific context, we present an 'organization structure and design' workshop approach for collaborative multi-discipline design management. The workshops set-up, used to implement and to test the approach, are presented as well as the experiences of the participants. The project was done in close cooperation with the professional societies with in the Dutch building design field. More than one hundred experienced professionals participated in the workshops. The workshops have become part of the permanent professional training program Dutch architectural society.

  2. Organization structure. Main activities of the Division

    International Nuclear Information System (INIS)

    In this chapter the organization structure as well as main activities of the Division for radiation safety, NPP decommissioning and radioactive waste management are presented. This Division of the VUJE, a.s. consists of the following sections and departments: Section for economic and technical services; Section for radiation protection of employees; Department for management of emergency situations and risk assessment; Department for implementation of nuclear power facilities decommissioning and RAW management; Department for personnel and environmental dosimetry; Department for preparation of NPP decommissioning; Department for RAW treatment technologies; Department for chemical regimes and physico-chemical analyses; Department for management of nuclear power facilities decommissioning and RAW management. Main activities of this Division are presented.

  3. Matrix Organizational Structure and Its Effects Upon Education Organizations.

    Science.gov (United States)

    Yates, James R.

    Applying matrix organizational structure to the organization of special education services is the focus of this paper. Beginning with a list of ways in which educational organizations differ from business or military organizations, the author warns that educators must be cautious when transferring organizational structures from other disciplines…

  4. Structural Capability of an Organization toward Innovation Capability

    DEFF Research Database (Denmark)

    Nielsen, Susanne Balslev; Momeni, Mostafa

    2016-01-01

    competitive advantage in the organizations is the innovation capability. The innovation capability is associated with other organizational capabilities, and many organizations have focused on the need to identify innovation capabilities.This research focuses on recognition of the structural aspect...

  5. Organic superconductors with an incommensurate anion structure

    Directory of Open Access Journals (Sweden)

    Tadashi Kawamoto and Kazuo Takimiya

    2009-01-01

    Full Text Available Superconducting incommensurate organic composite crystals based on the methylenedithio-tetraselenafulvalene (MDT-TSF series donors, where the energy band filling deviates from the usual 3/4-filled, are reviewed. The incommensurate anion potential reconstructs the Fermi surface for both (MDT-TSF(AuI20.436 and (MDT-ST(I30.417 neither by the fundamental anion periodicity q nor by 2q, but by 3q, where MDT-ST is 5H-2-(1,3-dithiol-2-ylidene-1,3-diselena-4,6-dithiapentalene, and q is the reciprocal lattice vector of the anion lattice. The selection rule of the reconstructing vectors is associated with the magnitude of the incommensurate potential. The considerably large interlayer transfer integral and three-dimensional superconducting properties are due to the direct donor–donor interactions coming from the characteristic corrugated conducting sheet structure. The materials with high superconducting transition temperature, Tc, have large ratios of the observed cyclotron masses to the bare ones, which indicates that the strength of the many-body effect is the major determinant of Tc. (MDT-TS(AuI20.441 shows a metal–insulator transition at TMI=50 K, where MDT-TS is 5H-2-(1,3-diselenol-2-ylidene-1,3,4,6-tetrathiapentalene, and the insulating phase is an antiferromagnet with a high Néel temperature (TN=50 K and a high spin–flop field (Bsf=6.9 T. There is a possibility that this material is an incommensurate Mott insulator. Hydrostatic pressure suppresses the insulating state and induces superconductivity at Tc=3.2 K above 1.05 GPa, where Tc rises to the maximum, Tcmax=4.9 K at 1.27 GPa. This compound shows a usual temperature–pressure phase diagram, in which the superconducting phase borders on the antiferromagnetic insulating phase, despite the unusual band filling.

  6. Lexical and constructional organization of argument structure: a contrastive analysis

    DEFF Research Database (Denmark)

    Pedersen, Johan

    2009-01-01

    exclusive focus on lexicalization patterns. Contrastive analysis may provide insight into differing ways of organizing grammatical information. Construction grammar (CXG) suggests that clausal core information is organized by integrating at least two construction types: A) schematic constructions, B...... of constructional specificity at which the core information is organized. English (and presumably other Germanic languages to some extent) tends to organize principal clausal information in schematic argument structure constructions, lea­ving secondary information for lexical (verbal) specification. Spanish (and...... presumably other Romance languages to some extent) seems to organize principal clausal information lexically in verbal argument structure constructions, leaving secondary information for schematically organized specification....

  7. STRUCTURE OF WAVE FRONT AND ORGANIZATION CENTER IN EXCITABLE MEDIA

    Institute of Scientific and Technical Information of China (English)

    刘深泉

    2004-01-01

    With help of establishing the moving coordinate on the wave front surface and the perturbation analysis in the boundary layer, the structures of wave front and organization center in excitable media were studied. The eikonal equation of wave front surface and general equation of organization center were obtained. These eikonal equations reveal the wave front surfaces have structures of twisted scroll wave and Mobius band, the organization centers have structures of knotted and linked ring. These theoretical results not only explain the wave patterns of BZ ( Belousov-Zhabotinskii ) chemical reaction but also give several possibility structures of wave front surface and organization center in general excitable media.

  8. Novel Structuring Routines for Organic Photovoltaics

    OpenAIRE

    Meier, Robert

    2012-01-01

    Organic photovoltaic devices are promising candidates for a future energy production at low-costs. In the framework of this thesis, fundamental aspects of organic solar cells based on different blend systems were investigated. X-ray scattering revealed a strong dependency of the inner film morphology of such devices on the layer thickness and the film composition. Applying optical methods, an enhanced photochemical degradation of blend films upon UV-irradiation was observed if ...

  9. Metal Organic Frameworks: From Structure to Property

    OpenAIRE

    Bu, Fei

    2016-01-01

    Porous Materials are an important class of materials due to their large-scale industrial applications in gas adsorption, gas separation, heterogeneous catalysis and so on. Among many kinds of porous materials, metal organic frameworks (MOFs) have emerged as one of the favorites in the past fifteen years. MOFs are crystalline porous materials that are mainly made of inorganic metal containing units (secondary building units, also called SBUs), organic ligands and templates.Compared to commerci...

  10. Structural Barriers: Redesigning Schools to Create Learning Organizations

    Science.gov (United States)

    Randeree, Ebrahim

    2006-01-01

    Purpose: The purpose of this paper is to focus on schools and address the structural dimensions of the organization as well as the hierarchical design of information flows between stakeholders. The paper highlights current structural barriers to creating learning organizations. Design/methodology/approach: This paper utilizes a conceptual model.…

  11. Scale and structure of capitated physician organizations in California.

    Science.gov (United States)

    Rosenthal, M B; Frank, R G; Buchanan, J L; Epstein, A M

    2001-01-01

    Physician organizations in California broke new ground in the 1980s by accepting capitated contracts and taking on utilization management functions. In this paper we present new data that document the scale, structure, and vertical affiliations of physician organizations that accept capitation in California. We provide information on capitated enrollment, the share of revenue derived by physician organizations from capitation contracts, and the scope of risk sharing with health maintenance organizations (HMOs). Capitation contracts and risk sharing dominate payment arrangements with HMOs. Physician organizations appear to have responded to capitation by affiliating with hospitals and management companies, adopting hybrid organizational structures, and consolidating into larger entities.

  12. Interface Structure of MoO3 on Organic Semiconductors

    OpenAIRE

    White, Robin T.; Thibau, Emmanuel S.; Zheng-Hong Lu

    2016-01-01

    We have systematically studied interface structure formed by vapor-phase deposition of typical transition metal oxide MoO3 on organic semiconductors. Eight organic hole transport materials have been used in this study. Ultraviolet photoelectron spectroscopy and X-ray photoelectron spectroscopy are used to measure the evolution of the physical, chemical and electronic structure of the interfaces at various stages of MoO3 deposition on these organic semiconductor surfaces. For the interface phy...

  13. The Temporal Organization of Syllabic Structure

    Science.gov (United States)

    Shaw, Jason A.

    2010-01-01

    This dissertation develops analytical tools which enable rigorous evaluation of competing syllabic parses on the basis of temporal patterns in speech production data. The data come from the articulographic tracking of fleshpoints on target speech organs, e.g., tongue, lips, jaw, in experiments with native speakers of American English and Moroccan…

  14. [Classification of organisms and structuralism in biology].

    Science.gov (United States)

    Vasil'eva, L I

    2001-01-01

    Structuralism in biology is the oldest trend oriented to the search for natural "laws of forms" comparable with laws of growth of crystal, was revived at the end of 20th century on the basis of structuralist thought in socio-humanitarian sciences. The development of principal ideas of the linguistic structuralism in some aspects is similar to that of biological systematics, especially concerning the relationships between "system" and "evolution". However, apart from this general similarity, biological structuralism is strongly focused on familiar problems of the origin of diversity in nature. In their striving for the renovation of existing views, biological structuralists oppose the neo-darwinism emphasizing the existence of "law of forms", that are independent on heredity and genetic "determinism". The trend to develop so-called "rational taxonomy" is also characteristic of biological structuralism but this attempt failed being connected neither with Darwin's historicism nor with Plato's typology. PMID:11605547

  15. Virtuous organization: A structural equation modeling approach

    OpenAIRE

    Majid Zamahani; Ali Akbar Ahmadi; Mohammad Ali Sarlak; Hamideh Shekari

    2013-01-01

    For years, the idea of virtue was unfavorable among researchers and virtues were traditionally considered as culture-specific, relativistic and they were supposed to be associated with social conservatism, religious or moral dogmatism, and scientific irrelevance. Virtue and virtuousness have been recently considered seriously among organizational researchers. The proposed study of this paper examines the relationships between leadership, organizational culture, human resource, structure and p...

  16. Simulating Self-organization and Interference between Certain Hierarchical Structures.

    Science.gov (United States)

    Raczynski, Stanislaw

    2014-10-01

    A model of the dynamics and interactions between organizations with self-organizing hierarchical structures is presented for discrete events. The active objects of the model are individuals (people, organization members). The parameters of an individual are ability, corruption level, resources, and lust for power, among others. Three organizations are generated and interact with each other, attempting to gain more members and power. The individuals appear and disappear, due to a simple 'birth-and-death' process. If an individual disappears from the model, a corresponding reconfiguration in the hierarchical structure occurs. The organization's growth and macro-patterns are the result of the activities of the individuals. The aim of the simulation is to visualize the evolution of the organizations and the stability of the whole system. A 'steady state' for the model is rare; instead, in most parameter configurations, the model enters into oscillations.

  17. Structural hierarchy in flow-aligned hexagonally self-organized microphases with parallel polyelectrolytic structures

    NARCIS (Netherlands)

    Ruotsalainen, T; Torkkeli, M; Serimaa, R; Makela, T; Maki-Ontto, R; Ruokolainen, J; ten Brinke, G; Ikkala, O; Mäkelä, Tapio; Mäki-Ontto, Riikka

    2003-01-01

    We report a novel structural hierarchy where a flow-aligned hexagonal self-organized structure is combined with a polyelectrolytic self-organization on a smaller length scale and where the two structures are mutually parallel. Polystyrene-block-poly(4-vinylpyridine) (PS-block-P4VP) is selected with

  18. Structural organization of the mitochondrial respiratory chain.

    Science.gov (United States)

    Genova, Maria Luisa; Bianchi, Cristina; Lenaz, Giorgio

    2003-03-01

    Two models exist of the mitochondrial respiratory chain: the model of a random organization of the individual respiratory enzyme complexes and that of a super-complex assembly formed by stable association between the individual complexes. Recently Schägger, using digitonin solubilization and Blue Native PAGE produced new evidence of preferential associations, in particular a Complex I monomer with a Complex III dimer, and suggested a model of the respiratory chain (the respirasome) based on direct electron channelling between complexes. Discrimination between the two models is amenable to kinetic testing using flux control analysis. Experimental evidence obtained in beef heart SMP, according to the extension of the Metabolic Control Theory for pathways with metabolic channelling, showed that enzyme associations involving Complex I and Complex III take place in the respiratory chain while Complex IV seems to be randomly distributed, with cytochrome c behaving as a mobile component. Flux control analysis at anyone of the respiratory complexes involved in aerobic succinate oxidation indicated that Complex II and III are not functionally associated in a stable supercomplex. A critical appraisal of the solid-state model of the mitochondrial respiratory chain requires its reconciliation with previous biophysical and kinetic evidence that CoQ behaves as a homogeneous diffusible pool between all reducing enzyme and all oxidizing enzymes: the hypothesis can be advanced that both models (CoQ pool and supercomplexes) are true, by postulating that supercomplexes physiologically exist in equilibrium with isolated complexes depending on metabolic conditions of the cell.

  19. Organic bulk heterojunction photovoltaic structures: design, morphology and properties

    International Nuclear Information System (INIS)

    Main approaches to the design of organic bulk heterojunction photovoltaic structures are generalized and systematized. Novel photovoltaic materials based on fullerenes, organic dyes and related compounds, graphene, conjugated polymers and dendrimers are considered. The emphasis is placed on correlations between the chemical structure and properties of materials. The effect of morphology of the photoactive layer on the photovoltaic properties of devices is analyzed. Main methods of optimization of the photovoltaic properties are outlined. The bibliography includes 338 references

  20. Controlled structuration and functionalization of organic-inorganic hybrid materials

    International Nuclear Information System (INIS)

    Organic-inorganic hybrid materials obtained by sol-gel process are very interesting materials. Indeed, these materials have both the properties of the organic phase and those of the inorganic matrix. Two functionalization and structuration ways are presented here: 1)the meso-porous hybrid materials formed in presence of structuring surfactant and the lamellar hybrid materials obtained by auto-assembling. (O.M.)

  1. Near Surface Structure of Organic Semiconductor Tetracene Single Crystal

    Science.gov (United States)

    Wakabayashi, Yusuke; Morisaki, Hazuki; Kimura, Tsuyoshi; Miwa, Kazumoto; Koretsune, Takashi; Takeya, Jun

    2014-03-01

    Electric conduction in organic crystals is highly anisotropic because of the anisotropic molecular orbitals. Crystal structure governs the transfer through the overlap integral among the highest occupied (or lowest unoccupied) molecular orbitals. In case of organic devices, the place where electrons conduct is the interface. Therefore, the surface structure of organic single crystals is relevant. Surface relaxation of the structure of rubrene single crystal was firstly observed by means of surface x-ray diffraction a few years ago. This time we performed similar measurement on tetracene single crystal, whose molecular shape has large similarity with rubrene while the crystal structure is very different. Tetracene single crystal was grown by the physical vapor transport method, and the surface x-ray diffraction experiments were performed at BL-3A and 4C of the Photon Factory, KEK, Japan. Obtained electron density profile shows a large structural deformation at the surface layer of tetracene.

  2. Structural organization of DNA in chlorella viruses.

    Directory of Open Access Journals (Sweden)

    Timo Wulfmeyer

    Full Text Available Chlorella viruses have icosahedral capsids with an internal membrane enclosing their large dsDNA genomes and associated proteins. Their genomes are packaged in the particles with a predicted DNA density of ca. 0.2 bp nm(-3. Occasionally infection of an algal cell by an individual particle fails and the viral DNA is dynamically ejected from the capsid. This shows that the release of the DNA generates a force, which can aid in the transfer of the genome into the host in a successful infection. Imaging of ejected viral DNA indicates that it is intimately associated with proteins in a periodic fashion. The bulk of the protein particles detected by atomic force microscopy have a size of ∼60 kDa and two proteins (A278L and A282L of about this size are among 6 basic putative DNA binding proteins found in a proteomic analysis of DNA binding proteins packaged in the virion. A combination of fluorescence images of ejected DNA and a bioinformatics analysis of the DNA reveal periodic patterns in the viral DNA. The periodic distribution of GC rich regions in the genome provides potential binding sites for basic proteins. This DNA/protein aggregation could be responsible for the periodic concentration of fluorescently labeled DNA observed in ejected viral DNA. Collectively the data indicate that the large chlorella viruses have a DNA packaging strategy that differs from bacteriophages; it involves proteins and share similarities to that of chromatin structure in eukaryotes.

  3. Polymeric Thin Films for Organic Electronics: Properties and Adaptive Structures

    Directory of Open Access Journals (Sweden)

    Bruno Pignataro

    2013-03-01

    Full Text Available This review deals with the correlation between morphology, structure and performance of organic electronic devices including thin film transistors and solar cells. In particular, we report on solution processed devices going into the role of the 3D supramolecular organization in determining their electronic properties. A selection of case studies from recent literature are reviewed, relying on solution methods for organic thin-film deposition which allow fine control of the supramolecular aggregation of polymers confined at surfaces in nanoscopic layers. A special focus is given to issues exploiting morphological structures stemming from the intrinsic polymeric dynamic adaptation under non-equilibrium conditions.

  4. Demand structure and willingness to pay for organic dairy products

    DEFF Research Database (Denmark)

    Smed, Sinne

    2005-01-01

    This paper analyses if the introduction of a new and “low fat” organic variety of fluid milk has any effect on consumers’ valuation of organic milk in general and can rewind the stagnating trend in the demand for organic milk. In order to analyse this, the consumers’ purchasing structure...... was analysed and it was found that consumers first chose between different types of milk and secondly, decided of whether this milk was organic or conventional. Elasticities indicated a greater temporary flexibility in the demand structure and a permanent change of substitution patterns through...... the introduction of the new type of milk. The calculation of marginal Willingness to Pay show a temporary raise in consumers’ valuation of the organic quality attribute, but this was followed by a decline....

  5. Structural complexities in the active layers of organic electronics.

    Science.gov (United States)

    Lee, Stephanie S; Loo, Yueh-Lin

    2010-01-01

    The field of organic electronics has progressed rapidly in recent years. However, understanding the direct structure-function relationships between the morphology in electrically active layers and the performance of devices composed of these materials has proven difficult. The morphology of active layers in organic electronics is inherently complex, with heterogeneities existing across multiple length scales, from subnanometer to micron and millimeter range. A major challenge still facing the organic electronics community is understanding how the morphology across all of the length scales in active layers collectively determines the device performance of organic electronics. In this review we highlight experiments that have contributed to the elucidation of structure-function relationships in organic electronics and also point to areas in which knowledge of such relationships is still lacking. Such knowledge will lead to the ability to select active materials on the basis of their inherent properties for the fabrication of devices with prespecified characteristics.

  6. Structural Genomics of Minimal Organisms: Pipeline and Results

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung-Hou; Shin, Dong-Hae; Kim, Rosalind; Adams, Paul; Chandonia, John-Marc

    2007-09-14

    The initial objective of the Berkeley Structural Genomics Center was to obtain a near complete three-dimensional (3D) structural information of all soluble proteins of two minimal organisms, closely related pathogens Mycoplasma genitalium and M. pneumoniae. The former has fewer than 500 genes and the latter has fewer than 700 genes. A semiautomated structural genomics pipeline was set up from target selection, cloning, expression, purification, and ultimately structural determination. At the time of this writing, structural information of more than 93percent of all soluble proteins of M. genitalium is avail able. This chapter summarizes the approaches taken by the authors' center.

  7. Self-organization and coherent structures in plasmas and fluids

    DEFF Research Database (Denmark)

    Nielsen, A.H.; Juul Rasmussen, J.; Schmidt, M.R.

    1996-01-01

    momentum the development into propagating dipolar structures is observed. This development is discussed by employing self-organization principles. The detailed structures of the evolving dipoles depends on the initial condition. It seems that there are no unique dipolar solutions, but a large class of...... solutions is possible. However, it is argued that the gross properties of the dipoles do not depend critically on the detailed structure. The vortical structures are found to trap particles and convect them over distances much larger than the scale size of the structure. Two examples of trapping...

  8. E-learning and the Educational Organizations Structure Reengineering (EOSR

    Directory of Open Access Journals (Sweden)

    Osama Alshara

    2007-06-01

    Full Text Available There are many calls for innovative learning methods that utilize advanced technologies. However, we will raise fundamental questions that look deep into the future of the educational organization. Can the educational institute survive without adapting learning technologies? Would the educational institute succeed in adapting new learning technologies without changing its organizational structure and processes? We claim that the answer to both questions is no. Our research will present the need for edu-cational institutes to incorporate learning technologies and focuses on the demand for the educational organization structure reengineering as a basic requirement for the suc-cess of incorporating learning technologies. Our study ex-plores the faculty requirements and policies and procedures of educational institutes in the UAE.The paper concludes with some discussions on findings from a case study of the need of educational organization struc-ture reengineering as a basic requirement for incorporating learning technologies.

  9. The Structure and Profitability of Organic Field Corn Production

    OpenAIRE

    McBride, William D.; Greene, Catherine; Foreman, Linda

    2013-01-01

    Results from long-term experimental trials suggest that similar yields and lower costs are possible from organic compared with conventional field crop production, but there is little information about the relative costs and returns on commercial farms. This study examines the structure and profitability of field corn production using a nationwide survey of corn producers for 2010 that includes a targeted sample of organic growers. Propensity score matching was used to develop a sample of simi...

  10. Self-assembled hierarchically structured organic-inorganic composite systems.

    Science.gov (United States)

    Tritschler, Ulrich; Cölfen, Helmut

    2016-06-01

    Designing bio-inspired, multifunctional organic-inorganic composite materials is one of the most popular current research objectives. Due to the high complexity of biocomposite structures found in nacre and bone, for example, a one-pot scalable and versatile synthesis approach addressing structural key features of biominerals and affording bio-inspired, multifunctional organic-inorganic composites with advanced physical properties is highly challenging. This article reviews recent progress in synthesizing organic-inorganic composite materials via various self-assembly techniques and in this context highlights a recently developed bio-inspired synthesis concept for the fabrication of hierarchically structured, organic-inorganic composite materials. This one-step self-organization concept based on simultaneous liquid crystal formation of anisotropic inorganic nanoparticles and a functional liquid crystalline polymer turned out to be simple, fast, scalable and versatile, leading to various (multi-)functional composite materials, which exhibit hierarchical structuring over several length scales. Consequently, this synthesis approach is relevant for further progress and scientific breakthrough in the research field of bio-inspired and biomimetic materials. PMID:27175790

  11. Stochastic models for plant microtubule self-organization and structure.

    Science.gov (United States)

    Eren, Ezgi C; Dixit, Ram; Gautam, Natarajan

    2015-12-01

    One of the key enablers of shape and growth in plant cells is the cortical microtubule (CMT) system, which is a polymer array that forms an appropriately-structured scaffolding in each cell. Plant biologists have shown that stochastic dynamics and simple rules of interactions between CMTs can lead to a coaligned CMT array structure. However, the mechanisms and conditions that cause CMT arrays to become organized are not well understood. It is prohibitively time-consuming to use actual plants to study the effect of various genetic mutations and environmental conditions on CMT self-organization. In fact, even computer simulations with multiple replications are not fast enough due to the spatio-temporal complexity of the system. To redress this shortcoming, we develop analytical models and methods for expeditiously computing CMT system metrics that are related to self-organization and array structure. In particular, we formulate a mean-field model to derive sufficient conditions for the organization to occur. We show that growth-prone dynamics itself is sufficient to lead to organization in presence of interactions in the system. In addition, for such systems, we develop predictive methods for estimation of system metrics such as expected average length and number of CMTs over time, using a stochastic fluid-flow model, transient analysis, and approximation algorithms tailored to our problem. We illustrate the effectiveness of our approach through numerical test instances and discuss biological insights. PMID:25700800

  12. Self-organized structures in soft confined thin films

    Indian Academy of Sciences (India)

    Ashutosh Sharma

    2005-10-01

    We present a mini-review of our recent work on spontaneous, self-organized creation of mesostructures in soft materials like thin films of polymeric liquids and elastic solids. These very small scale, highly confined systems are inherently unstable and thus self-organize into ordered structures which can be exploited for MEMS, sensors, opto-electronic devices and a host of other nanotechnology applications. In particular, mesomechanics requires incorporation of intermolecular interactions and surface tension forces, which are usually inconsequential in classical macroscale mechanics. We point to some experiments and quasi-continuum simulations of self-organized structures in thin soft films which are germane not only to nanotechnology, but also to a spectrum of classical issues such as adhesion/debonding, wetting, coatings, tribology and membranes.

  13. Coevolution of the Organization and Structure of Prokaryotic Genomes.

    Science.gov (United States)

    Touchon, Marie; Rocha, Eduardo P C

    2016-01-01

    The cytoplasm of prokaryotes contains many molecular machines interacting directly with the chromosome. These vital interactions depend on the chromosome structure, as a molecule, and on the genome organization, as a unit of genetic information. Strong selection for the organization of the genetic elements implicated in these interactions drives replicon ploidy, gene distribution, operon conservation, and the formation of replication-associated traits. The genomes of prokaryotes are also very plastic with high rates of horizontal gene transfer and gene loss. The evolutionary conflicts between plasticity and organization lead to the formation of regions with high genetic diversity whose impact on chromosome structure is poorly understood. Prokaryotic genomes are remarkable documents of natural history because they carry the imprint of all of these selective and mutational forces. Their study allows a better understanding of molecular mechanisms, their impact on microbial evolution, and how they can be tinkered in synthetic biology. PMID:26729648

  14. Consumer knowledge structures with regards to organic foods

    DEFF Research Database (Denmark)

    Bredahl, Lone; Thøgersen, John; Dean, Moira;

    2004-01-01

    This paper presents results of an empirical study conducted among European consumers to explore consumer knowledge structures with regard to organic foods and to identify the beliefs and the attribute-to-value chains that discriminate best among different consumer segments. Using means-end chain......; through hierarchical value maps and through perceptual maps derived from correspondence analyses, both across stimuli. Results point to marked differences in knowledge structures concerning organic foods among consumer segments, both at product-knowledge level and at self-knowledge level. The exact values...... associated with self-relevant consequences do not appear to discriminate clearly among segments, however. Generally, organic origin has significant links to personal values among segments of adventurous, enthusiastic, hedonistic and eco-healthy food consumers while it appears a dysfunctional means...

  15. Structural diversity in serine derived homochiral metal organic frameworks

    Indian Academy of Sciences (India)

    Tanay Kundu; Rahul Banerjee

    2014-09-01

    Two new Zn(II) and Cd(II) based homochiral metal-organic frameworks (MOFs) [SerCdOAc and Zn(Ser)2] have been synthesized using pyridyl functionalized amino acid, viz., serine, as an organic linker. The SerCdOAc structure is three dimensional, while that of the Zn(Ser)2 is two dimensional. The polar voids of the corresponding MOFs are filled with solvent molecules (water in the case of SerCdOAc and methanol in the case of Zn(Ser)2). In both cases, metal centres, i.e., Zn(II) and Cd(II), are hexacoordinated. However, with a change in the solvent for synthesis, ligand coordinationmode and incorporation of additional coordinated anion resulted in a great change in the final MOF architecture. Herein, for the first time, we could achieve structural variety and synthesize MOFs composed of only metal ion and pyridyl functionalized amino acid linker.

  16. Statistical theory of structure formation: self-organization

    OpenAIRE

    Kim, Eun-Jin; Liu, Han-Li; Anderson, Johan

    2008-01-01

    We present the first prediction of the probability distribution function (PDF) for self-organization of shear flows modeled by a nonlinear diffusion equation with a stochastic forcing. A novel non-perturbative method based on a coherent structure is utilized for the prediction of the PDFs, revealing strong intermittency with exponential tails. Numerical simulations confirm these results. The predicted power spectra are also in a good agreement with simulation results. The results imply a sign...

  17. Organic and inorganic-organic thin film structures by molecular layer deposition: A review.

    Science.gov (United States)

    Sundberg, Pia; Karppinen, Maarit

    2014-01-01

    The possibility to deposit purely organic and hybrid inorganic-organic materials in a way parallel to the state-of-the-art gas-phase deposition method of inorganic thin films, i.e., atomic layer deposition (ALD), is currently experiencing a strongly growing interest. Like ALD in case of the inorganics, the emerging molecular layer deposition (MLD) technique for organic constituents can be employed to fabricate high-quality thin films and coatings with thickness and composition control on the molecular scale, even on complex three-dimensional structures. Moreover, by combining the two techniques, ALD and MLD, fundamentally new types of inorganic-organic hybrid materials can be produced. In this review article, we first describe the basic concepts regarding the MLD and ALD/MLD processes, followed by a comprehensive review of the various precursors and precursor pairs so far employed in these processes. Finally, we discuss the first proof-of-concept experiments in which the newly developed MLD and ALD/MLD processes are exploited to fabricate novel multilayer and nanostructure architectures by combining different inorganic, organic and hybrid material layers into on-demand designed mixtures, superlattices and nanolaminates, and employing new innovative nanotemplates or post-deposition treatments to, e.g., selectively decompose parts of the structure. Such layer-engineered and/or nanostructured hybrid materials with exciting combinations of functional properties hold great promise for high-end technological applications. PMID:25161845

  18. Organic and inorganic–organic thin film structures by molecular layer deposition: A review

    Directory of Open Access Journals (Sweden)

    Pia Sundberg

    2014-07-01

    Full Text Available The possibility to deposit purely organic and hybrid inorganic–organic materials in a way parallel to the state-of-the-art gas-phase deposition method of inorganic thin films, i.e., atomic layer deposition (ALD, is currently experiencing a strongly growing interest. Like ALD in case of the inorganics, the emerging molecular layer deposition (MLD technique for organic constituents can be employed to fabricate high-quality thin films and coatings with thickness and composition control on the molecular scale, even on complex three-dimensional structures. Moreover, by combining the two techniques, ALD and MLD, fundamentally new types of inorganic–organic hybrid materials can be produced. In this review article, we first describe the basic concepts regarding the MLD and ALD/MLD processes, followed by a comprehensive review of the various precursors and precursor pairs so far employed in these processes. Finally, we discuss the first proof-of-concept experiments in which the newly developed MLD and ALD/MLD processes are exploited to fabricate novel multilayer and nanostructure architectures by combining different inorganic, organic and hybrid material layers into on-demand designed mixtures, superlattices and nanolaminates, and employing new innovative nanotemplates or post-deposition treatments to, e.g., selectively decompose parts of the structure. Such layer-engineered and/or nanostructured hybrid materials with exciting combinations of functional properties hold great promise for high-end technological applications.

  19. Organic/metal interfaces. Electronic and structural properties

    Energy Technology Data Exchange (ETDEWEB)

    Duhm, Steffen

    2008-07-17

    This work addresses several important topics of the field of organic electronics. The focus lies on organic/metal interfaces, which exist in all organic electronic devices. Physical properties of such interfaces are crucial for device performance. Four main topics have been covered: (i) the impact of molecular orientation on the energy levels, (ii) energy level tuning with strong electron acceptors, (iii) the role of thermodynamic equilibrium at organic/ organic homo-interfaces and (iv) the correlation of interfacial electronic structure and bonding distance. To address these issues a broad experimental approach was necessary: mainly ultraviolet photoelectron spectroscopy was used, supported by X-ray photoelectron spectroscopy, metastable atom electron spectroscopy, X-ray diffraction and X-ray standing waves, to examine vacuum sublimed thin films of conjugated organic molecules (COMs) in ultrahigh vacuum. (i) A novel approach is presented to explain the phenomenon that the ionization energy in molecular assemblies is orientation dependent. It is demonstrated that this is due to a macroscopic impact of intramolecular dipoles on the ionization energy in molecular assemblies. Furthermore, the correlation of molecular orientation and conformation has been studied in detail for COMs on various substrates. (ii) A new approach was developed to tune hole injection barriers ({delta}{sub h}) at organic/metal interfaces by adsorbing a (sub-) monolayer of an organic electron acceptor on the metal electrode. Charge transfer from the metal to the acceptor leads to a chemisorbed layer, which reduces {delta}{sub h} to the COM overlayer. This concept was tested with three acceptors and a lowering of {delta}{sub h} of up to 1.2 eV could be observed. (iii) A transition from vacuum-level alignment to molecular level pinning at the homo-interface between a lying monolayer and standing multilayers of a COM was observed, which depended on the amount of a pre-deposited acceptor. The

  20. Application of organic geochemistry to detect signatures of organic matter in the Haughton impact structure

    Science.gov (United States)

    Parnell, John; Lee, Pascal; Osinski, Gordon R.; Cockell, Charles S.

    2005-12-01

    Organic geochemistry applied to samples of bedrock and surface sediment from the Haughton impact structure detects a range of signatures representing the impact event and the transfer of organic matter from the crater bedrock to its erosion products. The bedrock dolomite contains hydrocarbon-bearing fluid inclusions which were incorporated before the impact event. Comparison of biomarker data from the hydrocarbons in samples inside and outside of the crater show the thermal signature of an impact. The occurrence of hydrocarbon inclusions in hydrothermal mineral samples shows that organic matter was mobilized and migrated in the immediate aftermath of the impact. The hydrocarbon signature was then transferred from bedrock to the crater-fill lacustrine deposits and present-day sediments in the crater, including wind-blown detritus in snow/ice. Separate signatures are detected from modern microbial life in crater rock and sediment samples. Signatures in Haughton crater samples are readily detectable because they include hydrocarbons generated by the burial of organic matter. This type of organic matter is not expected in crater samples on other planets, but the Haughton data show that, using very high resolution detection of organic compounds, any signature of primitive life in the crater rocks could be transferred to surface detritus and so extend the sampling medium.

  1. Importance of structural makeup of biopolymers for organic contaminant sorption.

    Science.gov (United States)

    Wang, Xilong; Xing, Baoshan

    2007-05-15

    Sorption of pyrene, phenanthrene, naphthalene, and 1-naphthol by original (lignin, chitin, and cellulose) and coated biopolymers was examined. Organic carbon normalized distribution coefficients (Koc) of all compounds by the original biopolymers followed the order lignin > chitin > cellulose, in line with the order of their hydrophobicity. Hydrophobicity of structurally similar organic compounds is the main factor determining their ability to occupy sorption sites in biopolymers. Specific interactions (e.g., H-bonding) between 1-naphthol and chitin or cellulose increased its ability to occupy sorption sites. Lignin coating resulted in an increased Koc for phenanthrene (13.6 times for chitin and 6.9 times for cellulose) and 1-naphthol (6.0 times for chitin and 3.7 times for cellulose) relative to the acetone-treated chitin and cellulose. Also, these coated biopolymers had increased isotherm nonlinearity, due to the newly formed condensed domains. An increase in phenanthrene and 1-naphthol sorption by lignin-coated biopolymers as compared to chitin and cellulose was contributed by the newly created high-energy sites in condensed domains and coated lignin. Results of this study highlight the importance of the structural makeup of biopolymers in controlling the sorption of hydrophobic organic compounds.

  2. Structural Organization of Enzymes of the Phenylacetate Catabolic Hybrid Pathway

    Directory of Open Access Journals (Sweden)

    Andrey M. Grishin

    2015-06-01

    Full Text Available Aromatic compounds are the second most abundant class of molecules on the earth and frequent environmental pollutants. They are difficult to metabolize due to an inert chemical structure, and of all living organisms, only microbes have evolved biochemical pathways that can open an aromatic ring and catabolize thus formed organic molecules. In bacterial genomes, the phenylacetate (PA utilization pathway is abundant and represents the central route for degradation of a variety of organic compounds, whose degradation reactions converge at this pathway. The PA pathway is a hybrid pathway and combines the dual features of aerobic metabolism, i.e., usage of both oxygen to open the aromatic ring and of anaerobic metabolism—coenzyme A derivatization of PA. This allows the degradation process to be adapted to fluctuating oxygen conditions. In this review we focus on the structural and functional aspects of enzymes and their complexes involved in the PA degradation by the catabolic hybrid pathway. We discuss the ability of the central PaaABCE monooxygenase to reversibly oxygenate PA, the controlling mechanisms of epoxide concentration by the pathway enzymes, and the similarity of the PA utilization pathway to the benzoate utilization Box pathway and β-oxidation of fatty acids.

  3. Structural Organization of Enzymes of the Phenylacetate Catabolic Hybrid Pathway.

    Science.gov (United States)

    Grishin, Andrey M; Cygler, Miroslaw

    2015-06-12

    Aromatic compounds are the second most abundant class of molecules on the earth and frequent environmental pollutants. They are difficult to metabolize due to an inert chemical structure, and of all living organisms, only microbes have evolved biochemical pathways that can open an aromatic ring and catabolize thus formed organic molecules. In bacterial genomes, the phenylacetate (PA) utilization pathway is abundant and represents the central route for degradation of a variety of organic compounds, whose degradation reactions converge at this pathway. The PA pathway is a hybrid pathway and combines the dual features of aerobic metabolism, i.e., usage of both oxygen to open the aromatic ring and of anaerobic metabolism-coenzyme A derivatization of PA. This allows the degradation process to be adapted to fluctuating oxygen conditions. In this review we focus on the structural and functional aspects of enzymes and their complexes involved in the PA degradation by the catabolic hybrid pathway. We discuss the ability of the central PaaABCE monooxygenase to reversibly oxygenate PA, the controlling mechanisms of epoxide concentration by the pathway enzymes, and the similarity of the PA utilization pathway to the benzoate utilization Box pathway and β-oxidation of fatty acids.

  4. Organization, Structure and Activity of Proteins in Monolayers

    Energy Technology Data Exchange (ETDEWEB)

    Boucher,J.; Trudel, E.; Methot, M.; Desmeules, P.; Salesse, C.

    2007-01-01

    Many different processes take place at the cell membrane interface. Indeed, for instance, ligands bind membrane proteins which in turn activate peripheral membrane proteins, some of which are enzymes whose action is also located at the membrane interface. Native cell membranes are difficult to use to gain information on the activity of individual proteins at the membrane interface because of the large number of different proteins involved in membranous processes. Model membrane systems, such as monolayers at the air-water interface, have thus been extensively used during the last 50 years to reconstitute proteins and to gain information on their organization, structure and activity in membranes. In the present paper, we review the recent work we have performed with membrane and peripheral proteins as well as enzymes in monolayers at the air-water interface. We show that the structure and orientation of gramicidin has been determined by combining different methods. Furthermore, we demonstrate that the secondary structure of rhodopsin and bacteriorhodopsin is indistinguishable from that in native membranes when appropriate conditions are used. We also show that the kinetics and extent of monolayer binding of myristoylated recoverin is much faster than that of the nonmyristoylated form and that this binding is highly favored by the presence polyunsaturated phospholipids. Moreover, we show that the use of fragments of RPE65 allow determine which region of this protein is most likely involved in membrane binding. Monomolecular films were also used to further understand the hydrolysis of organized phospholipids by phospholipases A2 and C.

  5. Experimental investigation of multiple self-organized structures in plasma

    International Nuclear Information System (INIS)

    Complex space charge configuration emerges by self-organization in front of an electrode immersed in plasma when its potential is increased at a certain critical value. Consisting from a nucleus protected from the surrounding plasma by an electrical double layer, the complexity reveals an internal structure and behaviour which remind us primitive organisms. Thus the complexity is not static but stationary open system in which continuous decay is constantly compensated by substance and energy from the surrounding plasma. Endowed with a special kind of memory the complexity can work as an intelligent multifunctional system and consequently it is also able to perform innovations after selective interaction with an environment in evolution. Additionally, the complexity is able to replicate by division. (authors)

  6. Organic Light-Emitting Devices with Tandem Structure.

    Science.gov (United States)

    Chiba, Takayuki; Pu, Yong-Jin; Kido, Junji

    2016-06-01

    Tandem organic light-emitting devices (OLEDs) have attracted considerable attention for solid-state lighting and flat panel displays because their tandem architecture enables high efficiency and long operational lifetime simultaneously. In the tandem OLED structure, plural light-emitting units (LEUs) are stacked in series through a charge generation layer (CGL) and an electron injection layer (EIL). In this chapter, we focus on the key features of tandem OLEDs for high efficiency and long operational lifetimes. We also demonstrate the effect of the CGL comprising a Lewis acid, an n-type semiconductor metal oxide, and an organic electron-accepting material. We discuss the two types of EILs in tandem OLEDs: alkali metals containing n-type compounds and ultra-thin metals. Finally, we focus on the recent progress of the state-of-the-art solution-processed tandem OLEDs. PMID:27573273

  7. Structural templating of multiple polycrystalline layers in organic photovoltaic cells

    Energy Technology Data Exchange (ETDEWEB)

    Lassiter, Brian E; Lunt, Richard R; Renshaw, Kyle; Forrest, Stephen R.

    2010-09-01

    We demonstrate that organic photovoltaic cell performance is influenced by changes in the crystalline orientation of composite layer structures. A 1.5 nm thick self-organized, polycrystalline template layer of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) orients subsequently deposited layers of a diindenoperylene exciton blocking layer, and the donor, copper phthalocyanine (CuPc). Control over the crystalline orientation of the CuPc leads to changes in its frontier energy levels, absorption coefficient, and surface morphology, resulting in an increase of power conversion efficiency at 1 sun from 1.42 ± 0.04% to 2.19 ± 0.05% for a planar heterojunction and from 1.89 ± 0.05% to 2.49 ± 0.03% for a planar-mixed heterojunction.

  8. Structural templating of multiple polycrystalline layers in organic photovoltaic cells.

    Science.gov (United States)

    Lassiter, Brian E; Lunt, Richard R; Renshaw, C Kyle; Forrest, Stephen R

    2010-09-13

    We demonstrate that organic photovoltaic cell performance is influenced by changes in the crystalline orientation of composite layer structures. A 1.5 nm thick self-organized, polycrystalline template layer of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) orients subsequently deposited layers of a diindenoperylene exciton blocking layer, and the donor, copper phthalocyanine (CuPc). Control over the crystalline orientation of the CuPc leads to changes in its frontier energy levels, absorption coefficient, and surface morphology, resulting in an increase of power conversion efficiency at 1 sun from 1.42 ± 0.04% to 2.19 ± 0.05% for a planar heterojunction and from 1.89 ± 0.05% to 2.49 ± 0.03% for a planar-mixed heterojunction. PMID:21165074

  9. Study of organic solar cells with stacked bulk heterojunction structure

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xin-fang; XU Zheng; ZHAO Su-ling; ZHANG Fu-jun; LI Yan; WU Chun-yu; CHEN Yue-ning

    2008-01-01

    Organic solar cells with stacked bulk heterojunction(BHJ) are investigated based on conjugated polymer. By using the solution spin-coating method, Poly[2-methoxy, 5-(2'-ethyl-hexyloxy) -1,4-phenylene vinylene] (MEH-PPV) and ZnO nanoparticles (50 nm) are mixed as the optical sense layer. Ag is used as inter-layer to connect the upper BILl cell and the lower cell. The structures are ITO/PEDOT:PSS/MEH-PPV/Ag/MEH-PPV:ZnO/Al. The open circuit voltage (Voc) of a stacked cell is about 3.7 times of that of an individual organic solar cell (ITO/PEDOT:PSS/MEH-PPV/A1). The short circuit current (Jsc) of a stacked cell is increased by about 1.6 times of that of individual one.

  10. Emergence, self-organization and morphogenesis in biological structures.

    Science.gov (United States)

    Dobrescu, R; Purcarea, V I

    2011-01-01

    The paper discusses the connection between emergence, pattern formation and nonlinear dynamics, focusing on the similarity between discrete patterns and fractal structures, and then describes different solutions to model reaction-diffusion systems as representative processes in morphogenesis. A specific example is the diffusion limited aggregation growth process, illustrated by the simulation of the evolution of a bacterial colony that shows the roles of instability and sensitivity in non-equilibrium pattern formation. Based on this particular case, it is shown how self-organization could be achieved from non-organized agglomeration of separate entities, in a region of space. We conclude with some brief remarks about universality, predictability and long-term prospects for this field of research. PMID:21505578

  11. Lanthanides caged by the organic chelates; structural properties.

    Science.gov (United States)

    Smentek, Lidia

    2011-04-13

    The structure, in particular symmetry, geometry and morphology of organic chelates coordinated with the lanthanide ions are analyzed in the present review. This is the first part of a complete presentation of a theoretical description of the properties of systems, which are widely used in technology, but most of all, in molecular biology and medicine. The discussion is focused on the symmetry and geometry of the cages, since these features play a dominant role in the spectroscopic activity of the lanthanides caged by organic chelates. At the same time, the spectroscopic properties require more formal presentation in the language of Racah algebra, and deserve a separate analysis. In addition to the parent systems of DOTA, DOTP, EDTMP and CDTMP presented here, their modifications by various antennas are analyzed. The conclusions that have a strong impact upon the theory of the energy transfer and the sensitized luminescence of these systems are based on the results of numerical density functional theory calculations.

  12. Lanthanides caged by the organic chelates; structural properties

    Science.gov (United States)

    Smentek, Lidia

    2011-04-01

    The structure, in particular symmetry, geometry and morphology of organic chelates coordinated with the lanthanide ions are analyzed in the present review. This is the first part of a complete presentation of a theoretical description of the properties of systems, which are widely used in technology, but most of all, in molecular biology and medicine. The discussion is focused on the symmetry and geometry of the cages, since these features play a dominant role in the spectroscopic activity of the lanthanides caged by organic chelates. At the same time, the spectroscopic properties require more formal presentation in the language of Racah algebra, and deserve a separate analysis. In addition to the parent systems of DOTA, DOTP, EDTMP and CDTMP presented here, their modifications by various antennas are analyzed. The conclusions that have a strong impact upon the theory of the energy transfer and the sensitized luminescence of these systems are based on the results of numerical density functional theory calculations.

  13. Single-Walled Carbon-Nanotubes-Based Organic Memory Structures.

    Science.gov (United States)

    Fakher, Sundes; Nejm, Razan; Ayesh, Ahmad; Al-Ghaferi, Amal; Zeze, Dagou; Mabrook, Mohammed

    2016-01-01

    The electrical behaviour of organic memory structures, based on single-walled carbon-nanotubes (SWCNTs), metal-insulator-semiconductor (MIS) and thin film transistor (TFT) structures, using poly(methyl methacrylate) (PMMA) as the gate dielectric, are reported. The drain and source electrodes were fabricated by evaporating 50 nm gold, and the gate electrode was made from 50 nm-evaporated aluminium on a clean glass substrate. Thin films of SWCNTs, embedded within the insulating layer, were used as the floating gate. SWCNTs-based memory devices exhibited clear hysteresis in their electrical characteristics (capacitance-voltage (C-V) for MIS structures, as well as output and transfer characteristics for transistors). Both structures were shown to produce reliable and large memory windows by virtue of high capacity and reduced charge leakage. The hysteresis in the output and transfer characteristics, the shifts in the threshold voltage of the transfer characteristics, and the flat-band voltage shift in the MIS structures were attributed to the charging and discharging of the SWCNTs floating gate. Under an appropriate gate bias (1 s pulses), the floating gate is charged and discharged, resulting in significant threshold voltage shifts. Pulses as low as 1 V resulted in clear write and erase states. PMID:27598112

  14. Single-Walled Carbon-Nanotubes-Based Organic Memory Structures

    Directory of Open Access Journals (Sweden)

    Sundes Fakher

    2016-09-01

    Full Text Available The electrical behaviour of organic memory structures, based on single-walled carbon-nanotubes (SWCNTs, metal–insulator–semiconductor (MIS and thin film transistor (TFT structures, using poly(methyl methacrylate (PMMA as the gate dielectric, are reported. The drain and source electrodes were fabricated by evaporating 50 nm gold, and the gate electrode was made from 50 nm-evaporated aluminium on a clean glass substrate. Thin films of SWCNTs, embedded within the insulating layer, were used as the floating gate. SWCNTs-based memory devices exhibited clear hysteresis in their electrical characteristics (capacitance–voltage (C–V for MIS structures, as well as output and transfer characteristics for transistors. Both structures were shown to produce reliable and large memory windows by virtue of high capacity and reduced charge leakage. The hysteresis in the output and transfer characteristics, the shifts in the threshold voltage of the transfer characteristics, and the flat-band voltage shift in the MIS structures were attributed to the charging and discharging of the SWCNTs floating gate. Under an appropriate gate bias (1 s pulses, the floating gate is charged and discharged, resulting in significant threshold voltage shifts. Pulses as low as 1 V resulted in clear write and erase states.

  15. Modern electronic structure theory and applications in organic chemistry

    CERN Document Server

    Davidson, ER

    1997-01-01

    This volume focuses on the use of quantum theory to understand and explain experiments in organic chemistry. High level ab initio calculations, when properly performed, are useful in making quantitative distinctions between various possible interpretations of structures, reactions and spectra. Chemical reasoning based on simpler quantum models is, however, essential to enumerating the likely possibilities. The simpler models also often suggest the type of wave function likely to be involved in ground and excited states at various points along reaction paths. This preliminary understanding is n

  16. Similarities Between Biological and Social Networks in Their Structural Organization

    Science.gov (United States)

    Kahng, Byungnam; Lee, Deokjae; Kim, Pureun

    A branching tree is a tree that is generated through a multiplicative branching process starting from a root. A critical branching tree is a branching tree in which the mean branching number of each node is 1, so that the number of offspring neither decays to zero nor flourishes as the branching process goes on. Moreover, a scale-free branching tree is a branching tree in which the number of offspring is heterogeneous, and its distribution follows a power law. Here we examine three structures, two from biology (a phylogenetic tree and the skeletons of a yeast protein interaction network) and one from social science (a coauthorship network), and find that all these structures are scale-free critical branching trees. This suggests that evolutionary processes in such systems take place in bursts and in a self-organized manner.

  17. Improved interconnecting structure for a tandem organic light emitting diode

    International Nuclear Information System (INIS)

    Two-unit tandem organic light emitting diodes (OLEDs) employing two kinds of interconnecting structures, i.e. 5 nm lithium carbonate doped PTCDA (1:2 Li2CO3:PTCDA)/5 nm MoO3 and 5 nm Li2CO3 doped BCP (1:4 Li2CO3:BCP)/5 nm MoO3, have been fabricated, where PTCDA and BCP stand for 3, 4, 9, 10 perylenetetracarboxylic dianhydride and bathocuproine, respectively. Compared to the tandem OLED using the interconnecting structure of 5 nm 1:4 Li2CO3:BCP/5 nm MoO3, the one utilizing 5 nm 1:2 Li2CO3:PTCDA/5 nm MoO3 showed nearly same power efficiency and decreased operating voltage, mainly attributed to the higher electron conductivity of 1:2 Li2CO3:PTCDA relative to 1:4 Li2CO3:BCP. The charge generation and electron injection processes based on the interconnecting structure of 5 nm 1:2 Li2CO3:PTCDA/5 nm MoO3 were also discussed. We provide a simple and effective connecting structure to enhance the current conduction for tandem OLEDs

  18. Computational Design of Photovoltaic Materials with Self Organized Nano Structures

    Science.gov (United States)

    Sato, Kazunori; Katayama-Yoshida, Hiroshi

    2013-03-01

    Chalcopyrite and II-VI semiconductors, such as Cu(In, Ga)Se2, Cu2ZnSn(S, Se)4 and Cd(S, Te), are one of the most promising materials for low cost photovoltaic solar-cells. In this paper, based on first-principles calculations, we propose that self-organized nano-structures in these compounds will enhance the conversion efficiency. Our calculations are based on the KKR-CPA-LDA with the self-interaction correction. We also use VASP package for calculating mixing energy and effective interactions of the systems by using the cluster expansion method. For phase separating systems, we simulate nano-structure formation by using the Monte Carlo method. It is expected that the photo-generated electron-hole pairs are efficiently separated by the type-II interface and then effectively transferred along the quasi-one-dimensional structures. Moreover, we can expect multiplication of generated carriers due to the multi-exciton effects in nano-structures.

  19. Self-organizing wireless sensor networks for structural health monitoring

    Science.gov (United States)

    Basheer, Mohammed R.; Rao, Vittal S.; Derriso, Mark M.

    2003-07-01

    A smart sensor node has been developed which has (a) the ability to sense strain of the structure under observation, (b) process this raw sensor data in cooperation with its neighbors and (c) transmit the information to the end user. This network is designed to be self organizing in the sense of establishing and maintaining the inter node connectivity without the need for human intervention. For the envisioned application of structural health monitoring, wireless communication is the most practical solution for node interconnectivity not only because they eliminate interconnecting cables but also for their ability to establish communication links even in inaccessible regions. But wireless nework brings with it a number of issues such as interference, fault tolerant self organizing, multi-hop communication, energy effieiciency, routing and finally reliable operation in spite of massive complexity of the sysetm. This paper addresses the issue of fault tolerant self organiing in wireless sensor networks. We propose a new architecture called the Redundant Tree Network (RTN). RTN is a hierarchical network which exploits redundant links between nodes to provide reliability.

  20. Colorectal cancers mimic structural organization of normal colonic crypts.

    Directory of Open Access Journals (Sweden)

    Laura Cernat

    Full Text Available Colonic crypts are stereotypical structures with distinct stem cell, proliferating, and differentiating compartments. Colorectal cancers derive from colonic crypt epithelia but, in contrast, form morphologically disarrayed glands. In this study, we investigated to which extent colorectal cancers phenocopy colonic crypt architecture and thus preserve structural organization of the normal intestinal epithelium. A subset of colon cancers showed crypt-like compartments with high WNT activity and nuclear β-Catenin at the leading tumor edge, adjacent proliferation, and enhanced Cytokeratin 20 expression in most differentiated tumor epithelia of the tumor center. This architecture strongly depended on growth conditions, and was fully reproducible in mouse xenografts of cultured and primary colon cancer cells. Full crypt-like organization was associated with low tumor grade and was an independent prognostic marker of better survival in a collection of 221 colorectal cancers. Our findings suggest that full activation of preserved intestinal morphogenetic programs in colon cancer requires in vivo growth environments. Furthermore, crypt-like architecture was linked with less aggressive tumor biology, and may be useful to improve current colon cancer grading schemes.

  1. Syntheses, characterizations and crystal structures of three new organically templated or organically bonded zinc selenates

    International Nuclear Information System (INIS)

    Three new organically templated or organically bonded zinc selenates, namely, {H2bipy}Zn(SeO4)2(H2O)2 1 (bipy=4,4'-bipyridine), {H2pip}{Zn(SeO4)2(H2O)4}·2H2O 2 (pip=piprazine), and Zn(SeO4)(phen)(H2O)2 3 (phen=1,10-phenanthroline) have been synthesized by hydrothermal reactions. The structure of compound 1 features a 1D chain composed of [Zn(SeO4)2(H2O)2]2- anions. Compound 2 has a 2D layer structure built from {Zn(SeO4)2(H2O)4}2- anions that are cross-linked by doubly protonated piperazine cations via N-H···O hydrogen bonds. The structure of compound 3 contains a 1D chain of Zn(SeO4)(phen)(H2O)2, such chains are further interlinked by hydrogen bonds and π···π interactions to form a layer. The different roles the templates played have also been discussed

  2. Resolving detailed molecular structures in complex organic mixtures and modeling their secondary organic aerosol formation

    Science.gov (United States)

    Goodman-Rendall, Kevin A. S.; Zhuang, Yang R.; Amirav, Aviv; Chan, Arthur W. H.

    2016-03-01

    Characterization of unresolved complex mixtures (UCMs) remains an ongoing challenge towards developing detailed and accurate inputs for modeling secondary organic aerosol (SOA) formation. Traditional techniques based on gas chromatography/electron impact-mass spectrometry induce excessive fragmentation, making it difficult to speciate and quantify isomers precisely. The goal of this study is to identify individual organic isomers by gas chromatography/mass spectrometry with supersonic molecular beam (SMB-GC/MS, also known as GC/MS with Cold EI) and to incorporate speciated isomers into an SOA model that accounts for the specific structures elucidated. Two samples containing atmospherically relevant UCMs are analyzed. The relative isomer distributions exhibit remarkably consistent trends across a wide range of carbon numbers. Constitutional isomers of different alkanes are speciated and individually quantified as linear, branched - for the first time by position of branching - multiply branched, or unsaturated - by degree of ring substitution and number of rings. Relative amounts of exact molecular structures are used as input parameters in an SOA box model to study the effects of molecular structures on SOA yields and volatility evolution. Highly substituted cyclic, mono-substituted cyclic, and linear species have the highest SOA yields while branched alkanes formed the least SOA. The rate of functionalization of a representative UCM is found to be in agreement with current volatility basis set (VBS) parameterizations based on detailed knowledge of composition and known oxidation mechanisms, confirming the validity of VBS parameters currently used in air quality models.

  3. The structure of organic langmuir films on liquid metal surfaces

    International Nuclear Information System (INIS)

    Langmuir films (LFs) on water have long been studied for their interest for basic science and their numerous applications in chemistry, physics, materials science and biology. We present here A-resolution synchrotron X-ray studies of the structure of stearic acid LFs on a liquid mercury surface. At low coverage, ≥110 A2/mol, a 2D gas phase of flat-lying molecules is observed. At high coverage, ≤23 A2/mol, two different hexatic phases of standing-up molecules are observed. At intermediate coverage, 52≤A≤110 A2/mol, novel single- and double-layered phases of flat-lying molecular dimers are found, exhibiting a 1D in-layer order. Such flat-lying phases were not hitherto observed in any LF. Measurements on LFs of fatty acids of other chain lengths indicate that this structure is generic to chain molecules on mercury, although the existence of some of the flat-lying phases, and the observed phase sequence, depend on the chain length. Organic LFs on Hg, and in particular the new flat-lying phases, should provide a broader nano-structural tunability range for molecular electronic device construction than most solid-supported self-assembled monolayers used at present

  4. ORGANIZING SCENARIO VARIABLES BY APPLYING THE INTERPRETATIVE STRUCTURAL MODELING (ISM

    Directory of Open Access Journals (Sweden)

    Daniel Estima de Carvalho

    2009-10-01

    Full Text Available The scenario building method is a thought mode - taken to effect in an optimized, strategic manner - based on trends and uncertain events, concerning a large variety of potential results that may impact the future of an organization.In this study, the objective is to contribute towards a possible improvement in Godet and Schoemaker´s scenario preparation methods, by employing the Interpretative Structural Modeling (ISM as a tool for the analysis of variables.Given this is an exploratory theme, bibliographical research with tool definition and analysis, examples extraction from literature and a comparison exercise of referred methods, were undertaken.It was verified that ISM may substitute or complement the original tools for the analysis of variables of scenarios per Godet and Schoemaker’s methods, given the fact that it enables an in-depth analysis of relations between variables in a shorter period of time, facilitating both structuring and construction of possible scenarios.Key-words: Strategy. Future studies. Interpretative Structural Modeling.

  5. Nanoscale Structure Of Organic Matter Explain Its Recalcitrance To Degradation

    Science.gov (United States)

    Spagnol, M.; Salati, S.; Papa, G.; Tambone, F.; Adani, F.

    2009-04-01

    Recalcitrance can be defined as the natural resistance of organic matter (OM) to microbial and enzymatic deconstruction (Himmel et al., 2007). The nature of OM recalcitrance remained not completely understood and more studies need above all to elucidate the role of the chemical topography of the OM at nanometer scale. Hydrolytic enzymes responsible of OM degradation have a molecular weight of 20-25 kD, corresponding to a size of about 4 nm, hardly penetrate into micropores (i.e. the pore having a diameter humic acid, was isolated and studied. Laboratory simulated landfill considered organic fraction of municipal solid waste sampled at different stages of evolution from a full scale plant and incubated under anaerobic condition for one year. In addition the nano-scale structure of fossilized OM (leonardite, chair coal and graphite) was detected as used as model of recalcitrant OM. Nano-scale structures were detected by using meso and microporosity detection. In particular microporosity was determined by adsorption method using CO2 at 273 K and Non Local Density Functional Theory (NLDFT) method was applied to measure the CO2 adsorption isotherms. On the other hand mesoporosity was detected by using N2 adsorption method at 77 K. The BET (Brunauer-Emmett-Teller) equation and the BJH (Barret-Joyner-Halenda) equation were applied respectively to measure specific surface area and mesoporosity. Macromolecular composition of OM was investigated by using CP MAS 13NMR and wet chemical analyses. Results obtained showed how OM evolved increasing microporosity and decreasing meso porosity. This was the result of the preservation of recalcitrant OM versus degradation of the more labile fraction, suggesting that the more recalcitrant fraction was characterized by high microporosity. Another confirmation of these results comes from the analysis of the same OM after the removing of the labile fraction by acid hydrolysis to discover the core-OM, which was characterized by a higher

  6. Structure and function of vanadium compounds in living organisms.

    Science.gov (United States)

    Rehder, D

    1992-01-01

    Vanadium has been recognized as a metal of biological importance only recently. In this mini-review, its main functions uncovered during the past few years are addressed. These encompass (i) the regulation of phosphate metabolizing enzymes (which is exemplified for the inhibition of ribonucleases by vanadate), (ii) the halogenation of organic compounds by vanadate-dependent non-heme peroxidases from seaweeds, (iii) the reductive protonation of nitrogen (nitrogen fixation) by alternative, i.e. vanadium-containing, nitrogenases from N2-fixing bacteria, (iv) vanadium sequestering by sea squirts (ascidians), and (v) amavadine, a low molecular weight complex of V(IV) accumulated in the fly agaric and related toadstools. The function of vanadium, while still illusive in ascidians and toadstools, begins to be understood in vanadium-enzyme interaction. Investigations into the structure and function of model compounds play an increasingly important role in elucidating the biological significance of vanadium. PMID:1392470

  7. Organization and Structure of Branched Amphipathic Oligopeptide Bilayers.

    Science.gov (United States)

    Jia, Zhiguang; Whitaker, Susan K; Tomich, John M; Chen, Jianhan

    2016-09-27

    A class of self-assembling branched amphiphilic peptide capsules (BAPCs) was recently developed that could serve as a new drug delivery vehicle. BAPCs can encapsulate solutes up to ∼12 kDa during assembly, are unusually stable, and are readily taken up by cells with low cytotoxicity. Coarse-grained simulations have supported that BAPCs are defined by bilayers that resemble those formed by diacyl phospholipids. Here, atomistic simulations were performed to characterize the structure and organization of bilayers formed by three branched amphiphilic peptides (BAPs): bis(Ac-FLIVIGSII)-K-K4-CO-NH2, bis(Ac-CHA-LIVIGSII)-K-K4-CO-NH2, and bis(Ac-FLIVI)-K-K4-CO-NH2. The results show BAPs form a network of intra- and intermolecular backbone hydrogen bonds within the same leaflet in addition to hydrophobic side-chain interactions. The terminal residues of two leaflets form an interdigitation region locking two leaflets together. The phenyl groups in bis(Ac-FLIVIGSII)-K-K4-CO-NH2 and bis(Ac-FLIVI)-K-K4-CO-NH2 are tightly packed near the bilayer center but do not formed ordered structures with specific π-π stacking. Replacing phenyl groups with the cyclohexane side chain only slightly increases the level of disorder in bilayer structures and thus should not significantly affect the stability, consistent with experimental results on bis(Ac-CHA-LIVIGSII)-K-K4-CO-NH2 BAPCs. Self-assembly simulations further suggest that leaflet interdigitation likely occurs at early stages of BAPC formation. Atomistic simulations also reveal that the BAPC bilayers are highly permeable to water. This prediction was validated using fluorescence measurements of encapsulated self-quenching dye upon transferring BAPCs to buffers with different salt concentrations. Improved understanding of the organization and structure of BAPC bilayers at the atomic level will provide a basis for future rational modifications of BAP sequence to improve BAPC properties as a new class of delivery vehicle. PMID

  8. Chemical-Structural Changes of Organic Matter in a Semi-Arid Soil After Organic Amendment

    Institute of Scientific and Technical Information of China (English)

    C.NICOL(A)S; G.MASCIANDARO; T.HERN(A)NDEZ; C.GARCIA

    2012-01-01

    A 9-month incubation experiment using composted and non-composted amendments derived from vine pruning waste and sewage sludge was carried out to study the effects of the nature and stability of organic amendments on the structural composition of organic matter (OM) in a semi-arid soil. The changes of soil OM,both in the whole soil and in the extractable carbon with pyrophosphate,were evaluated by pyrolysis-gas chromatography and chemical analyses.By the end of the experiment,the soils amended with pruning waste exhibited less organic carbon loss than those receiving sewage sludge.The non-composted residues increased the aliphatic-pyrolytic products of the OM,both in the whole soil and also in the pyrophosphate extract,with the products derived from peptides and proteins being significantly higher.After 9 months,in the soils amended with pruning waste the relative abundance of phenolic-pyrolytic products derived from phenolic compounds,lignin and proteins in the whole soil tended to increase more than those in the soils amended with sewage sludge.However,the extractable OM with pyrophosphate in the soils amended with composted residues tended to have higher contents of these phenolic-pyrolytic products than that in non-composted ones.Thus,despite the stability of pruning waste,the composting of this material promoted the incorporation of phenolic compounds to the soil OM.The pyrolytic indices (furfural/pyrrole and aliphatic/aromatic ratios) showed the diminution of aliphatic compounds and the increase of aromatic compounds,indicating the stabilization of the OM in the amended soils after 9 months.In conclusion,the changes of soil OM depend on the nature and stability of the organic amendments,with composted vine pruning waste favouring humification.

  9. Adaptive symbiotic organisms search (SOS algorithm for structural design optimization

    Directory of Open Access Journals (Sweden)

    Ghanshyam G. Tejani

    2016-07-01

    Full Text Available The symbiotic organisms search (SOS algorithm is an effective metaheuristic developed in 2014, which mimics the symbiotic relationship among the living beings, such as mutualism, commensalism, and parasitism, to survive in the ecosystem. In this study, three modified versions of the SOS algorithm are proposed by introducing adaptive benefit factors in the basic SOS algorithm to improve its efficiency. The basic SOS algorithm only considers benefit factors, whereas the proposed variants of the SOS algorithm, consider effective combinations of adaptive benefit factors and benefit factors to study their competence to lay down a good balance between exploration and exploitation of the search space. The proposed algorithms are tested to suit its applications to the engineering structures subjected to dynamic excitation, which may lead to undesirable vibrations. Structure optimization problems become more challenging if the shape and size variables are taken into account along with the frequency. To check the feasibility and effectiveness of the proposed algorithms, six different planar and space trusses are subjected to experimental analysis. The results obtained using the proposed methods are compared with those obtained using other optimization methods well established in the literature. The results reveal that the adaptive SOS algorithm is more reliable and efficient than the basic SOS algorithm and other state-of-the-art algorithms.

  10. Structural order in additive processed bulk heterojunction organic solar cells

    Science.gov (United States)

    Rogers, James Thomas

    Considerable academic and industrial efforts have been dedicated to resolving scientific and technological issues associated with the fabrication of efficient plastic solar cells via solution deposition techniques. The most successful strategy used to generate solution processable devices implements a two component donor-acceptor type system composed of a (p-type) narrow bandgap conjugated polymer donor blended with a (n-type) fullerene acceptor. Due to the limited exciton diffusion lengths (~10 nm) inherent to these materials, efficient photoinduced charge generation requires heterojunction formation (i.e. donor/acceptor interfaces) in close proximity to the region of exciton generation. Maximal charge extraction therefore requires that donor and acceptor components form nanoscale phase separated percolating pathways to their respective electrodes. Devices exhibiting these structural characteristics are termed bulk heterojunction devices (BHJ). Although the BHJ architecture highlights the basic characteristics of functional donor-acceptor type organic solar cells, device optimization requires internal order within each phase and proper organization relative to the substrate in order to maximize charge transport efficiencies and minimize charge carrier recombination losses. The economic viability of BHJ solar cells hinges upon the minimization of processing costs; thus, commercially relevant processing techniques should generate optimal structural characteristics during film formation, eliminating the need for additional post deposition processing steps. Empirical optimization has shown that solution deposition using high boiling point additives (e.g. octanedithiol (ODT)) provides a simple and widely used fabrication method for maximizing the power conversion efficiencies of BHJ solar cells. This work will show using x-ray scattering that a small percentage of ODT (~2%) in chlorobenzene induces the nucleation of polymeric crystallites within 2 min of deposition

  11. Structural organization of the inactive X chromosome in the mouse.

    Science.gov (United States)

    Giorgetti, Luca; Lajoie, Bryan R; Carter, Ava C; Attia, Mikael; Zhan, Ye; Xu, Jin; Chen, Chong Jian; Kaplan, Noam; Chang, Howard Y; Heard, Edith; Dekker, Job

    2016-07-28

    X-chromosome inactivation (XCI) involves major reorganization of the X chromosome as it becomes silent and heterochromatic. During female mammalian development, XCI is triggered by upregulation of the non-coding Xist RNA from one of the two X chromosomes. Xist coats the chromosome in cis and induces silencing of almost all genes via its A-repeat region, although some genes (constitutive escapees) avoid silencing in most cell types, and others (facultative escapees) escape XCI only in specific contexts. A role for Xist in organizing the inactive X (Xi) chromosome has been proposed. Recent chromosome conformation capture approaches have revealed global loss of local structure on the Xi chromosome and formation of large mega-domains, separated by a region containing the DXZ4 macrosatellite. However, the molecular architecture of the Xi chromosome, in both the silent and expressed regions,remains unclear. Here we investigate the structure, chromatin accessibility and expression status of the mouse Xi chromosome in highly polymorphic clonal neural progenitors (NPCs) and embryonic stem cells. We demonstrate a crucial role for Xist and the DXZ4-containing boundary in shaping Xi chromosome structure using allele-specific genome-wide chromosome conformation capture (Hi-C) analysis, an assay for transposase-accessible chromatin with high throughput sequencing (ATAC-seq) and RNA sequencing. Deletion of the boundary disrupts mega-domain formation, and induction of Xist RNA initiates formation of the boundary and the loss of DNA accessibility. We also show that in NPCs, the Xi chromosome lacks active/inactive compartments and topologically associating domains (TADs), except around genes that escape XCI. Escapee gene clusters display TAD-like structures and retain DNA accessibility at promoter-proximal and CTCF-binding sites. Furthermore, altered patterns of facultative escape genes indifferent neural progenitor clones are associated with the presence of different TAD

  12. Structural organization of the inactive X chromosome in the mouse.

    Science.gov (United States)

    Giorgetti, Luca; Lajoie, Bryan R; Carter, Ava C; Attia, Mikael; Zhan, Ye; Xu, Jin; Chen, Chong Jian; Kaplan, Noam; Chang, Howard Y; Heard, Edith; Dekker, Job

    2016-07-28

    X-chromosome inactivation (XCI) involves major reorganization of the X chromosome as it becomes silent and heterochromatic. During female mammalian development, XCI is triggered by upregulation of the non-coding Xist RNA from one of the two X chromosomes. Xist coats the chromosome in cis and induces silencing of almost all genes via its A-repeat region, although some genes (constitutive escapees) avoid silencing in most cell types, and others (facultative escapees) escape XCI only in specific contexts. A role for Xist in organizing the inactive X (Xi) chromosome has been proposed. Recent chromosome conformation capture approaches have revealed global loss of local structure on the Xi chromosome and formation of large mega-domains, separated by a region containing the DXZ4 macrosatellite. However, the molecular architecture of the Xi chromosome, in both the silent and expressed regions,remains unclear. Here we investigate the structure, chromatin accessibility and expression status of the mouse Xi chromosome in highly polymorphic clonal neural progenitors (NPCs) and embryonic stem cells. We demonstrate a crucial role for Xist and the DXZ4-containing boundary in shaping Xi chromosome structure using allele-specific genome-wide chromosome conformation capture (Hi-C) analysis, an assay for transposase-accessible chromatin with high throughput sequencing (ATAC-seq) and RNA sequencing. Deletion of the boundary disrupts mega-domain formation, and induction of Xist RNA initiates formation of the boundary and the loss of DNA accessibility. We also show that in NPCs, the Xi chromosome lacks active/inactive compartments and topologically associating domains (TADs), except around genes that escape XCI. Escapee gene clusters display TAD-like structures and retain DNA accessibility at promoter-proximal and CTCF-binding sites. Furthermore, altered patterns of facultative escape genes indifferent neural progenitor clones are associated with the presence of different TAD

  13. Structure of vomeronasal organ (Jacobson organ) in male Camelus Domesticus Var. dromedaris persica.

    Science.gov (United States)

    Karimi, H; Mansoori Ale Hashem, R; Ardalani, G; Sadrkhanloo, R; Hayatgheibi, H

    2014-12-01

    The vomeronasal organ (VNO) is a tubular structure in the roof of nasal cavity. The important role of this organ is olfaction of sexual odour. In this study, position, anatomical structure and histology of VNO in Iranian camels (camelus domesticus var. dromedaris persica) were determined. Fourteen healthy male camel heads were collected from an industrial slaughterhouse in Tehran, Iran, for anatomical and histological studies (seven each). The length of VNO and width of dental pad and the number and width of palatine crests were measured. For anatomical studies, the mandible was removed, and maxilla and nasal cavity was cut longitudinally and transversely. For histological studies, the mandible was removed, and first 0.5 cm of initial part of VNO was cut. Then, nasal cavity was cut in some segments with 2 cm thickness. The width of VNO was 3.85 ± 0.31 cm and 1.57 ± 0.18 cm in front and distal parts, respectively. The length of VNO was 15.61 ± 0.59 cm. In histological examinations, VNO was surrounded by J-shape hyaline cartilage. The lining epithelium of lateral wall of VNO was originated from respiratory epithelium, while it had an olfactory epithelium origin in the medial wall. Lamina propria and tunica submucosa were a cavernous connective tissue with seromucous gland with abundant of serous secretory units. The lumen of VNO opens into nasal cavity. The presence of olfactory epithelium found in our study indicates an important role for VNO in pheromone perception and beginning of sexual behaviour. PMID:24611976

  14. Resonance energy transfer in self-organized organic/inorganic dendrite structures

    Science.gov (United States)

    Melnikau, D.; Savateeva, D.; Lesnyak, V.; Gaponik, N.; Fernández, Y. Núnez; Vasilevskiy, M. I.; Costa, M. F.; Mochalov, K. E.; Oleinikov, V.; Rakovich, Y. P.

    2013-09-01

    Hybrid materials formed by semiconductor quantum dots and J-aggregates of cyanine dyes provide a unique combination of enhanced absorption in inorganic constituents with large oscillator strength and extremely narrow exciton bands of the organic component. The optical properties of dendrite structures with fractal dimension 1.7-1.8, formed from J-aggregates integrated with CdTe quantum dots (QDs), have been investigated by photoluminescence spectroscopy and fluorescence lifetime imaging microscopy. Our results demonstrate that (i) J-aggregates are coupled to QDs by Förster-type resonant energy transfer and (ii) there are energy fluxes from the periphery to the centre of the structure, where the QD density is higher than in the periphery of the dendrite. Such an anisotropic energy transport can be only observed when dendrites are formed from QDs integrated with J-aggregates. These QD/J-aggregate hybrid systems can have applications in light harvesting systems and optical sensors with extended absorption spectra.

  15. Study on the local atomic structure of germanium in organic germanium compounds by EXAFS

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Organic germanium compounds have been extensively applied in medicine as tonics,In this paper,the local structures of two organic germanium compounds,carboxyethylgermanium sesquioxide and polymeric germanium glutamate,were determined by EXAFS.The structure parameters including coordination numbers and bond lengths were reported,and possible structure patterns were discussed.

  16. Automatic Structure Determination of Organic Molecules: Principle and Implementation of the LSD Program

    Institute of Scientific and Technical Information of China (English)

    NUZILLARD,Jean-Marc

    2003-01-01

    The LSD (Logic for Structure Determination) program generates organic molecular structures from 1D and 2D NMR data without resorting to chemical shift databases. Its use in the resolution of natural product structure determination problems has been already reported in the literature. This paper describes how data and structures are internally represented and processed by LSD to build solution structures.

  17. Perceptual Organization of Visual Structure Requires a Flexible Learning Mechanism

    Science.gov (United States)

    Aslin, Richard N.

    2011-01-01

    Bhatt and Quinn (2011) provide a compelling and comprehensive review of empirical evidence that supports the operation of principles of perceptual organization in young infants. They also have provided a comprehensive list of experiences that could serve to trigger the learning of at least some of these principles of perceptual organization, and…

  18. THE EXTENT OF CLONAL STRUCTURE IN DIFFERENT LYMPHOID ORGANS

    NARCIS (Netherlands)

    HERMANS, MHA; WUBBENA, A; KROESE, FGM; HUNT, SV; COWAN, R; OPSTELTEN, D

    1992-01-01

    To gain insight into the clonal organization of lymphoid organs, we studied the distribution in situ of donor-derived cells in near-physiological chimeras. We introduced RT7b fetal liver cells into nonirradiated congenic RT7a neonatal rats. The chimerism 6-20 wk after injection ranged from 0.3 to 20

  19. Giddens' "structuration," Luhmann's "self-organization," and the operationalization of the dynamics of meaning

    CERN Document Server

    Leydesdorff, Loet

    2009-01-01

    Luhmann's social systems theory and Giddens' structuration theory of action share an emphasis on reflexivity, but focus on meaning along a divide between inter-human communication and intentful action as two different systems of reference. Recombining these two theories, simulations of interaction, organization, and self-organization of intentional communication can be distinguished by using algorithms from the computation of anticipatory systems. The self-organizing and organizing layers remain rooted in the double contingency of the human encounter which provides the variation. Organization and self-organization of communication are reflexive upon and therefore reconstructive of each other. Using mutual information in three dimensions, the imprint of meaning processing in the modeling system on the historical organization of uncertainty in the modeled system can be measured. This is shown empirically in the case of intellectual organization as "structurating" structure in the textual domain of scientific ar...

  20. Making a Self-feeding Structure by Assembly of Digital Organs

    Science.gov (United States)

    Cussat-Blanc, Sylvain; Luga, Hervé; Duthen, Yves

    In Nature, the intrinsic cooperation between organism's parts is capital. Most living systems are composed of organs, functional units specialized for specific actions. In our last research, we developed an evolutionary model able to generate artificial organs. This paper deals with the assembly of organs. We show, through experimentation, the development of an artificial organism composed of four digital organs able to produce a self-feeding organism. This kind of structure has applications in the mophogenetic-engineering of future nano and bio robots.

  1. Organic Farm Structure by Category of Agricultural Use

    Directory of Open Access Journals (Sweden)

    Manuela Dora Orboi

    2015-10-01

    Full Text Available Organic production systems are based on specific and precise standards of production, pursuing the achievement of optimal agro-systems, easy to sustain in terms of social, environmental and economic. Organic production systems plays a dual social role, because, on the one hand provides for a specific market that is responding to consumer demand for organic products, and on the other hand delivers public goods, contributing to environmental protection, animal welfare and rural development. The main goal of organic agriculture is to optimize the health and productivity of interdependent communities of soil, plants, animals and humans, providing new guidance of agricultural diversification in a general context of protecting the environment and promoting the development of sustainable agriculture. In 2013, the continent with the largest organic cultivated surface was Australia / Oceania, over 17.3 million, up to 5 million hectares compared to 2011, followed by Europe with 11.4 mil. Ha, Latin America - 6.6 million ha, Asia - 3.4 million ha North America - 3.0 million ha and Africa - 1.2 million ha of the 43.1 million total hectares grown in organic management system, almost two thirds are permanent pastures (27 million hectares, followed by agricultural land area totaling 10.9 million ha (arable land - 7.7 million ha permanent crops - 3.2 million ha.

  2. Teachers' Organization of Participation Structures for Teaching Science with Computer Technology

    Science.gov (United States)

    Subramaniam, Karthigeyan

    2016-01-01

    This paper describes a qualitative study that investigated the nature of the participation structures and how the participation structures were organized by four science teachers when they constructed and communicated science content in their classrooms with computer technology. Participation structures focus on the activity structures and…

  3. Research on Structure Innovation of Agricultural Organization in China’s Southwestern Mountainous Regions

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Taking agricultural organization in China’s southwestern mountainous regions as research object,on the basis of analysis of the status quo of agricultural organization development in China’s southwestern mountainous regions,we use related theoretical knowledge on economics and organization science,we probe into the process of innovation and mechanism of action concerning the structure of agricultural organization in China’s southwestern mountainous regions over the past 30 years.Finally we draw several general conclusions regarding structure innovation of agricultural organization in China’s southwestern mountainous regions as follows:first,the structure innovation of agricultural organization,a gradual process,proceeds ceaselessly along with ongoing progress and development of agriculture,and in this process,farmers always play a fundamental role;second,the structure innovation of agricultural organization is affected by many factors,and government institutional arrangement and change in market conditions is undoubtedly the most critical factor;third,the probable evolving direction of structure innovation of agricultural organization includes internal differentiation of the same form of agricultural organization,association of different forms of agricultural organization,and emergence of other forms of agricultural organization.

  4. Self-organization of muscle cell structure and function.

    Directory of Open Access Journals (Sweden)

    Anna Grosberg

    2011-02-01

    Full Text Available The organization of muscle is the product of functional adaptation over several length scales spanning from the sarcomere to the muscle bundle. One possible strategy for solving this multiscale coupling problem is to physically constrain the muscle cells in microenvironments that potentiate the organization of their intracellular space. We hypothesized that boundary conditions in the extracellular space potentiate the organization of cytoskeletal scaffolds for directed sarcomeregenesis. We developed a quantitative model of how the cytoskeleton of neonatal rat ventricular myocytes organizes with respect to geometric cues in the extracellular matrix. Numerical results and in vitro assays to control myocyte shape indicated that distinct cytoskeletal architectures arise from two temporally-ordered, organizational processes: the interaction between actin fibers, premyofibrils and focal adhesions, as well as cooperative alignment and parallel bundling of nascent myofibrils. Our results suggest that a hierarchy of mechanisms regulate the self-organization of the contractile cytoskeleton and that a positive feedback loop is responsible for initiating the break in symmetry, potentiated by extracellular boundary conditions, is required to polarize the contractile cytoskeleton.

  5. Self-organization of muscle cell structure and function.

    Science.gov (United States)

    Grosberg, Anna; Kuo, Po-Ling; Guo, Chin-Lin; Geisse, Nicholas A; Bray, Mark-Anthony; Adams, William J; Sheehy, Sean P; Parker, Kevin Kit

    2011-02-01

    The organization of muscle is the product of functional adaptation over several length scales spanning from the sarcomere to the muscle bundle. One possible strategy for solving this multiscale coupling problem is to physically constrain the muscle cells in microenvironments that potentiate the organization of their intracellular space. We hypothesized that boundary conditions in the extracellular space potentiate the organization of cytoskeletal scaffolds for directed sarcomeregenesis. We developed a quantitative model of how the cytoskeleton of neonatal rat ventricular myocytes organizes with respect to geometric cues in the extracellular matrix. Numerical results and in vitro assays to control myocyte shape indicated that distinct cytoskeletal architectures arise from two temporally-ordered, organizational processes: the interaction between actin fibers, premyofibrils and focal adhesions, as well as cooperative alignment and parallel bundling of nascent myofibrils. Our results suggest that a hierarchy of mechanisms regulate the self-organization of the contractile cytoskeleton and that a positive feedback loop is responsible for initiating the break in symmetry, potentiated by extracellular boundary conditions, is required to polarize the contractile cytoskeleton.

  6. Interracial Friendship and Structural Diversity: Trends for Greek, Religious, and Ethnic Student Organizations

    Science.gov (United States)

    Park, Julie J.; Kim, Young K.

    2013-01-01

    This article examines how peer interactions in college organizations (Greek, ethnic, and religious) affect interracial friendships, including whether peer interaction in student organizations mediates the relationship between structural diversity and interracial friendship. Involvement in ethnic student organizations was non-significant;…

  7. Structure of the Buried Metal-Molecule Interface in Organic Thin Film Devices

    DEFF Research Database (Denmark)

    Hansen, Christian Rein; Sørensen, Thomas Just; Glyvradal, Magni;

    2009-01-01

    . By comparison of XR data for the five-layer Pb2+ arachidate LB film before and after vapor deposition of the Ti/Al top electrode, a detailed account of the structural damage to the organic film at the buried metal-molecule interface is obtained. We find that the organized structure of the two topmost LB layers...

  8. 47 CFR 90.1408 - Organization and structure of the 700 MHz public/private partnership.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Organization and structure of the 700 MHz public/private partnership. 90.1408 Section 90.1408 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Partnership § 90.1408 Organization and structure of the 700 MHz public/private partnership. (a) The Upper...

  9. Lewis acidic metal catalysed organic transformations by designed multi-component structures and assemblies

    Indian Academy of Sciences (India)

    Afsar Ali; Amit P Singh; Rajeev Gupta

    2010-05-01

    This paper presents the recent developments in designing multi-component structures including metal-organic frameworks containing Lewis acidic metal ions. The emphasis has been given to understand the design elements adopted to synthesize such structures bearing Lewis acidic metal ion. Further, few important Lewis acidic metal catalysed organic transformation reactions have been discussed demonstrating the importance of such materials for practical purposes.

  10. A Study on the Organization Structure of Third-party Logistics Enterprise Servicing for Manufacturing Enterprise

    OpenAIRE

    Xiaoye Zhou; Xiuyi Xie

    2009-01-01

    This paper introduces ways and advantages of third-party logistics enterprise servicing manufacturing enterprise, analyses supply-chain of manufacturing enterprise and further studies for the organization structure of third-party logistics enterprise servicing manufacturing enterprise, to seek to the enterprise organization structure which has the best combination in third-party logistics enterprise with manufacturing enterprise.

  11. 47 CFR 27.1308 - Organization and structure of the 700 MHz public/private partnership.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Organization and structure of the 700 MHz... Partnership § 27.1308 Organization and structure of the 700 MHz public/private partnership. (a) The Upper 700... the Upper 700 MHz D Block license shall also form the Operating Company, which must also be a...

  12. Spiral organization of periodic structures in the Lorenz–Stenflo system

    Science.gov (United States)

    Rech, Paulo C.

    2016-07-01

    This paper reports the existence of organized periodic structures embedded in chaotic regions of a parameter plane of the Lorenz–Stenflo system. More specifically, this work reports on spiral organization of periodic structures observed in the (σ, s) parameter plane of the Lorenz–Stenflo system.

  13. Design of control adaptability system model for TV media organization structure

    Institute of Scientific and Technical Information of China (English)

    WANG Dong-dong; WANG Ya-lin; MA Tao

    2008-01-01

    To resolve the control adaptability problem of TV media in complex competitive environment, a con-trol system model of TV media organization structure was designed. Based on the designed system model for TV media organization structure, the relations among the main factors of the system constitution, missions, organi-zing decision entity, and carrying bodies were analyzed. By means of applying multi-objective decision method and complex control system theory, and combining the integration model of TV media organization structure, the basic model was concluded and the corresponding parameters were designed. The current organization process of TV media is analyzed by this model, which comes to the adaptability appearance with different parameters. The results indicate that the model can estimate current TV media organization structure for the chain appearance of communications and the correlation between platforms and policy-making agencies.

  14. Approaches to Establishing the Chemical Structure of Extraterrestrial Organic Solids

    Science.gov (United States)

    Cody, G. D.; Alexander, C. M. OD.; Wirick, Susan

    2003-01-01

    The majority of extraterrestrial organic matter in carbonaceous chondrites resides in a chemically complex, insoluble and perhaps macromolecular phase. We have been applying a series of independent solid state NMR experiments that are designed to provide a self consistent chemical characterization of this complex material. To date we have thoroughly analyzed 8 organic residues from different meteorites, including a CR2 (EET92042), CIl(Orgueil), CM2 (Murchison), Tagish Lake, CM2 (AlH83100), CM2 (Cold Bokkefeld), CM2 (Mighei), CM3 (Y86720). In fig 1. (1)H to (13)C cross polarization NMR spectra of four of these are shown. Note that there exists an enormous range in chemistry exhibited in organic solid [evident by the breadth of the spectral features both in the aliphatic region (sp(sup 3)) and the aromatic region (sp(sup 2))]. There is also considerable differences in the carbon chemistry across the meteorite groups.

  15. INMARSAT - The International Maritime Satellite Organization: Origins and structure

    Science.gov (United States)

    Doyle, S. E.

    1977-01-01

    The third session of the International Conference on the Establishment of an International Maritime Satellite System established the International Maritime Satellite Organization (INMARSAT) in 1976. Its main functions are to improve maritime communications via satellite, thereby facilitating more efficient emergency communications, ship management, and maritime public correspondence services. INMARSAT's aims are similar to those of the Intergovernmental Maritime Consultative Organization (IMCO), the main United Nations organization dealing with maritime affairs. The specific functions of INMARSAT have been established by an Intersessional Working Group (IWG) which met three times between general conference meetings. Initial investment shares for the creation of INMARSAT were shared by the United States (17%), the United Kingdom (12%), the U.S.S.R. (11%), Norway (9.50%), Japan (8.45%), Italy (4.37%), and France (3.50%).

  16. IMPLEMENTATION OF GREEN IT IN ORGANIZATIONS: A STRUCTURATIONAL VIEW

    Directory of Open Access Journals (Sweden)

    Décio Bittencourt Dolci

    2015-08-01

    Full Text Available Environmental sustainability has become increasingly important to businesses as a response to the rapid depletion of natural resources. Information Technology (IT in particular represents a meaningful part of the environmental issues that society has been facing. Therefore, Green IT emerges as a way of combining available resources and sustainable and economic policies, thus, generating benefits for both the environment and businesses. The purpose of this paper, hence, is to explain the dynamics of Green IT implementation in organizations in light of the structurationist view of technology. We conducted a case study research based on the cases of three Brazilian companies interested in this movement. Results provide a better understanding of the relationship among technology, individuals, and organization institutional properties, thus enhancing the role played by IT teams in institutionalizing the environmental dimension of sustainability in organizations.

  17. Studies on the Structure Evolvement of Organic Agricultural Industry in Taiwan and its Influential Factors

    Institute of Scientific and Technical Information of China (English)

    Xin; XU; Zheng; ZHANG; Li; KONG

    2014-01-01

    In order to study the development of organic agriculture in Taiwan in recent years,and based on relevant agriculture,economic and social statistics,the general scale of organic agriculture and industrial structure were treated with statistic analysis. Results suggest that the general scale of organic agriculture in Taiwan grew rapidly from 2004 to 2011. The certified organic farmers grew by 140. 59%,and the area with organic plantation grew by 302. 40%. The industrial structure has changed significantly as vegetables have become the No. 1 organic crop instead of rice. Besides of the four major crops,organic plantation has played an increasingly important role. Essential factors influencing the great-leap-forward development include the general trend of agricultural industrial structure adjustment,proliferation of management system and strategic opportunities brought by economic cycles.

  18. Structural organization of mammalian prions as probed by limited proteolysis

    Science.gov (United States)

    The GPI- transgenic mouse model was used to study the structure of GPI- prions. We obtained valuable information about the structure of prions by performing limited proteolysis of the GPI- prions and analyzing the results by mass spectrometry and Western blot. This information coupled with previous ...

  19. Social Capital in Organizations - Beyond Structure and Metaphor

    DEFF Research Database (Denmark)

    Waldstrøm, Christian

    2003-01-01

    in future research before social capital can move definitively beyond being merely a metaphor for advantage. First, the unresolved issue of causality is a barrier in the study of social structure and social capital alike, and hampers both measuring scales and implications drawn from empirical research...... in each of the mentioned areas - separately and concurrently - in order to move beyond structure and metaphor....

  20. Organic structures design applications in optical and electronic devices

    CERN Document Server

    Chow, Tahsin J

    2014-01-01

    ""Presenting an overview of the syntheses and properties of organic molecules and their applications in optical and electronic devices, this book covers aspects concerning theoretical modeling for electron transfer, solution-processed micro- and nanomaterials, donor-acceptor cyclophanes, molecular motors, organogels, polyazaacenes, fluorogenic sensors based on calix[4]arenes, and organic light-emitting diodes. The publication of this book is timely because these topics have become very popular nowadays. The book is definitely an excellent reference for scientists working in these a

  1. The Communication of Meaning and the Structuration of Expectations: Giddens' "structuration theory" and Luhmann's "self-organization"

    OpenAIRE

    Leydesdorff, Loet

    2009-01-01

    The communication of meaning as different from (Shannon-type) information is central to Luhmann's social systems theory and Giddens' structuration theory of action. These theories share an emphasis on reflexivity, but focus on meaning along a divide between inter-human communication and intentful action as two different systems of reference. Recombining these two theories into a theory about the structuration of expectations, interactions, organization, and self-organization of intentional co...

  2. Organizational Structures and Data Use in Volunteer Monitoring Organizations (VMOs)

    Science.gov (United States)

    Laird, Shelby Gull; Nelson, Stacy A. C.; Stubbs, Harriett S.; James, April L.; Menius, Erika

    2012-01-01

    Complex environmental problems call for unique solutions to monitoring efforts alongside developing a more environmentally literate citizenry. Community-based monitoring (CBM) through the use of volunteer monitoring organizations helps to provide a part of the solution, particularly when CBM groups work with research scientists or government…

  3. Organizing innovation within incumbent firms: structure enabling strategic autonomy

    NARCIS (Netherlands)

    Looy, van Bart; Visscher, Klaasjan

    2011-01-01

    In this paper we will discuss how large established firms can be effective in organizing innovation alongside their current business. We examine the trajectory of an incumbent firm in the telecommunication industry – Alcatel – which has been successful in exploring and exploiting the promises of bro

  4. Research on Structure Innovation of Agricultural Organization in China's Southwestern Mountainous Regions

    OpenAIRE

    Du, Qiang; Luo, Min; Wang, Ping

    2012-01-01

    Taking agricultural organization in China's southwestern mountainous regions as research object, on the basis of analysis of the status quo of agricultural organization development in China's southwestern mountainous regions, we use related theoretical knowledge on economics and organization science, we probe into the process of innovation and mechanism of action concerning the structure of agricultural organization in China's southwestern mountainous regions over the past 30 years. Finally w...

  5. Structural elements and organization of the ancestral translational machinery

    Science.gov (United States)

    Rein, R.; Srinivasan, S.; McDonald, J.; Raghunathan, G.; Shibata, M.

    1987-09-01

    The molecular mechanisms underlying the primitive translational apparatus have been studied in light of present day protein biosynthesis. Using the structural information available from the contemporary system as a key to its function, both the structural necessities for an early adaptor and the multipoint recognition properties of such adaptors have been investigated. This was done by first critically examining the potential feasibility of right- and left-handed hairpin adaptor models. Second, a molecular model of the contemporary transpeptidation complex has been constructed in order to ascertain the structural requirements of the adaptor molecule needed for peptidyl transfer. Third, a model of the tRNATyr-tyrosyl tRNA synthetase complex including the positioning of the disordered region is proposed. This model is used to illustrate those required recognition properties of aminoacyl synthetase which lead to a perspective on the structure of the ancestor synthetase.

  6. Expert system for elucidation of structures of organic compounds——Structural generator of ESESOC-II

    Institute of Scientific and Technical Information of China (English)

    胡昌玉; 许禄

    1995-01-01

    An expert system for the elucidation of the structures of organic compounds--ESESOC-IIhas been designed. It is composed of three parts: spectroscopic data analysis, structure generator, and evaluation of the candidate structures. The heart of ESESOC is the structure generator, as an integral part, which accepts the specific types of information, e.g. molecular formulae, substructure constraints, and produces an exhaustive and irredundant list of candidate structures. The scheme for the structural generation is given, in which the depth-first search strategy is used to fill the bonding adjacency matrix (BAM) and a new method is introduced to remove the duplicates.

  7. Flexible organic solar cells including efficiency enhancing grating structures

    DEFF Research Database (Denmark)

    Oliveira Hansen, Roana Melina de; Liu, Yinghui; Madsen, Morten;

    2013-01-01

    In this work, a new method for the fabrication of organic solar cells containing functional light-trapping nanostructures on flexible substrates is presented. Polyimide is spin-coated on silicon support substrates, enabling standard micro- and nanotechnology fabrication techniques......, such as photolithography and electron-beam lithography, besides the steps required for the bulk-heterojunction organic solar cell fabrication. After the production steps, the solar cells on polyimide are peeled off the silicon support substrates, resulting in flexible devices containing nanostructures for light absorption...... enhancement. Since the solar cells avoid using brittle electrodes, the performance of the flexible devices is not affected by the peeling process. We have investigated three different nanostructured grating designs and conclude that gratings with a 500 nm pitch distance have the highest light...

  8. Molecular evolution, intracellular organization, and the quinary structure of proteins.

    OpenAIRE

    McConkey, E H

    1982-01-01

    High-resolution two-dimensional polyacrylamide gel electrophoresis shows that at least half of 370 denatured polypeptides from hamster cells and human cells are indistinguishable in terms of isoelectric points and molecular weights. Molecular evolution may have been more conservative for this set of proteins than sequence studies on soluble proteins have implied. This may be a consequence of complexities of intracellular organization and the numerous macromolecular interactions in which most ...

  9. Structural Changes of Japanese Firms: Strategy, organization, and behavior (Japanese)

    OpenAIRE

    Morikawa, Masayuki

    2012-01-01

    The purpose of this paper is to overview the characteristics of Japanese firms based on an original survey. Specifically, we analyze the changes in management strategy, corporate governance, internal organization, and business behavior of Japanese firms by comparing a survey conducted in the 1990s with a recent one using the same questionnaires. These surveys cover both listed and unlisted firms, which is an important advantage of this study. There are many stable characteristics: the longer ...

  10. Understanding Structure and Bonding of Multilayered Metal–Organic Nanostructures

    OpenAIRE

    Egger, D; Ruiz, V; Saidi, W.; Bučko, T.; Tkatchenko, A.; Zojer, E.

    2013-01-01

    For organic and hybrid electronic devices, the physicochemical properties of the contained interfaces play a dominant role. To disentangle the various interactions occurring at such heterointerfaces, we here model a complex, yet prototypical, three-component system consisting of a Cu–phthalocyanine (CuPc) film on a 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) monolayer adsorbed on Ag(111). The two encountered interfaces are similar, as in both cases there would be no bonding without ...

  11. Microbial biofilm structure and organic matter use in mediterranean streams

    OpenAIRE

    Romaní i Cornet, Anna M.; Amalfitano, Stefano; Artigas Alejo, Joan; Fazi, Stefano; Sabater, Sergi; Timoner Amer, Xisca; Ylla i Monfort, Irene; Zoppini, Annamaria

    2013-01-01

    River and stream biofilms in mediterranean fluvial ecosystems face both extreme seasonality as well as arrhythmic fluctuations. The hydrological extremes (droughts and floods) impose direct changes in water availability but also in the quantity and quality of organic matter and nutrients that sustain the microbial growth. This review analyzes how these ecological pulses might determine unique properties of biofilms developing in mediterranean streams. The paper brings together data from heter...

  12. Cluster-induced desorption from metal organic surfaces: Structural effects

    Energy Technology Data Exchange (ETDEWEB)

    Delcorte, A., E-mail: arnaud.delcorte@uclouvain.be [Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, 1 Croix du Sud, B-1348 Louvain-la-Neuve (Belgium); Hoecke, E. van; Restrepo, O.A. [Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, 1 Croix du Sud, B-1348 Louvain-la-Neuve (Belgium)

    2013-05-15

    Molecular dynamics (MD) simulations are used to model the 10 keV bombardment of Au-nanoparticle (NP)-covered polymeric samples by Ga, C{sub 60} and Au{sub 400} projectiles, at normal incidence. While the presence of the Au-NPs tends to enhance the organic material emission upon Ga and Au{sub 400} bombardment, as a result of increased projectile stopping, it strongly reduces the organic emission upon C{sub 60} bombardment because of the projectile reflection. Our results show that these trends are valid for kDa polymers (which can be emitted intact) as well as for virtually infinite length chains (which require fragmentation), but that the polymer sputtered mass is consistently >3 times larger in the case of the kDa molecules for all impact points and projectiles. Using a series of samples, it is also shown that embedding the Au-NPs in the organic material leads to completely different results, with, upon C{sub 60} bombardment, the largest sputtered masses observed for impacts above the NPs. For Au{sub 400} bombardment, the burial of the Au-NPs leads to comparatively lower sputtered masses. These new results demonstrate the complexity of the sputtering of nanostructured hybrid materials by cluster projectiles and suggest various artifacts that should complicate the analysis and depth profiling of such materials.

  13. Determination of organic crystal structures by X ray powder diffraction

    CERN Document Server

    McBride, L

    2000-01-01

    The crystal structure of Ibuprofen has been solved from synchrotron X-ray powder diffraction data using a genetic algorithm (GA). The performance of the GA is improved by incorporating prior chemical information in the form of hard limits on the values that can be taken by the flexible torsion angles within the molecule. Powder X-ray diffraction data were collected for the anti-convulsant compounds remacemide, remacemide nitrate and remacemide acetate at 130 K on BM 16 at the X-ray European Synchrotron Radiation Facility (ESRF) at Grenoble. High quality crystal structures were obtained using data collected to a resolution of typically 1.5 A. The structure determinations were performed using a simulated annealing (SA) method and constrained Rietveld refinements for the structures converged to chi sup 2 values of 1.64, 1.84 and 1.76 for the free base, nitrate and acetate respectively. The previously unknown crystal structure of the drug famotidine Form B has been solved using X-ray powder diffraction data colle...

  14. Self-organizing Knotted Magnetic Structures in Plasma

    CERN Document Server

    Smiet, C B; Thompson, A; Swearngin, J; Dalhuizen, J W; Bouwmeester, D

    2015-01-01

    We perform full-MHD simulations on various initially helical configurations and show that they reconfigure into a state where the magnetic field lines span nested toroidal surfaces. This relaxed configuration is not a Taylor state, as is often assumed for relaxing plasma, but a state where the Lorentz force is balanced by the hydrostatic pressure, which is lowest on the central ring of the nested tori. Furthermore, the structure is characterized by a spatially slowly varying rotational transform, which leads to the formation of a few magnetic islands at rational surfaces. We then obtain analytic expressions that approximate the global structure of the quasi-stable linked and knotted plasma configurations that emerge, using maps from $S^3$ to $S^2$ of which the Hopf fibration is a special case. The knotted plasma configurations have a highly localized magnetic energy density and retain their structure on time scales much longer than the Alfvenic time scale.

  15. Self-Organizing Knotted Magnetic Structures in Plasma.

    Science.gov (United States)

    Smiet, C B; Candelaresi, S; Thompson, A; Swearngin, J; Dalhuisen, J W; Bouwmeester, D

    2015-08-28

    We perform full-magnetohydrodynamics simulations on various initially helical configurations and show that they reconfigure into a state where the magnetic field lines span nested toroidal surfaces. This relaxed configuration is not a Taylor state, as is often assumed for relaxing plasma, but a state where the Lorentz force is balanced by the hydrostatic pressure, which is lowest on the central ring of the nested tori. Furthermore, the structure is characterized by a spatially slowly varying rotational transform, which leads to the formation of a few magnetic islands at rational surfaces. We then obtain analytic expressions that approximate the global structure of the quasistable linked and knotted plasma configurations that emerge, using maps from S^{3} to S^{2} of which the Hopf fibration is a special case. The knotted plasma configurations have a highly localized magnetic energy density and retain their structure on time scales much longer than the Alfvénic time scale. PMID:26371659

  16. Perceptual organization in computer vision - A review and a proposal for a classificatory structure

    Science.gov (United States)

    Sarkar, Sudeep; Boyer, Kim L.

    1993-01-01

    The evolution of perceptual organization in biological vision, and its necessity in advanced computer vision systems, arises from the characteristic that perception, the extraction of meaning from sensory input, is an intelligent process. This is particularly so for high order organisms and, analogically, for more sophisticated computational models. The role of perceptual organization in computer vision systems is explored. This is done from four vantage points. First, a brief history of perceptual organization research in both humans and computer vision is offered. Next, a classificatory structure in which to cast perceptual organization research to clarify both the nomenclature and the relationships among the many contributions is proposed. Thirdly, the perceptual organization work in computer vision in the context of this classificatory structure is reviewed. Finally, the array of computational techniques applied to perceptual organization problems in computer vision is surveyed.

  17. Microbial community structure affects marine dissolved organic matter composition

    Directory of Open Access Journals (Sweden)

    Elizabeth B Kujawinski

    2016-04-01

    Full Text Available Marine microbes are critical players in the global carbon cycle, affecting both the reduction of inorganic carbon and the remineralization of reduced organic compounds back to carbon dioxide. Members of microbial consortia all depend on marine dissolved organic matter (DOM and in turn, affect the molecules present in this heterogeneous pool. Our understanding of DOM produced by marine microbes is biased towards single species laboratory cultures or simplified field incubations, which exclude large phototrophs and protozoan grazers. Here we explore the interdependence of DOM composition and bacterial diversity in two mixed microbial consortia from coastal seawater: a whole water community and a <1.0-μm community dominated by heterotrophic bacteria. Each consortium was incubated with isotopically-labeled glucose for 9 days. Using stable-isotope probing techniques and electrospray ionization Fourier-transform ion cyclotron resonance mass spectrometry, we show that the presence of organisms larger than 1.0-μm is the dominant factor affecting bacterial diversity and low-molecular-weight (<1000 Da DOM composition over this experiment. In the <1.0-μm community, DOM composition was dominated by compounds with lipid and peptide character at all time points, confirmed by fragmentation spectra with peptide-containing neutral losses. In contrast, DOM composition in the whole water community was nearly identical to that in the initial coastal seawater. These differences in DOM composition persisted throughout the experiment despite shifts in bacterial diversity, underscoring an unappreciated role for larger microorganisms in constraining DOM composition in the marine environment.

  18. Structural Characterization and Toxicity Prediction of Some Organic Compounds

    Institute of Scientific and Technical Information of China (English)

    LIAO Li-Mia; LI Jian-Feng; WANG Bi

    2011-01-01

    A new molecular structural characterization(MSC)method called molecular vertexes correlative index(MVCI)was constructed in this paper.The index was used to describe the structures of 45 compounds and a quantitative structure-activity relationship(QSAR)model of toxicity(–lgEC50)was obtained through multiple linear regression(MLR)and stepwise multiple regression(SMR).The correlation coefficient(R)of the model was 0.912,and the standard deviation(SD)of the model was 0.525.The estimation stability and prediction ability of the model were strictly analyzed by both internal and external validations.The Leave-One-Out(LOO)Cross-Validation(CV)correlation coefficient(RCV)was 0.816 and the standard deviation(SDCV)was 0.739,respectively.For the external validation,the correlation coefficient(Rtest)was 0.905 and the standard deviation(SDtest)was 0.520,respectively.The results showed that the index was superior in molecular structural representation.The stability and predictability of the model were good.

  19. Structure Determination of Unknown Organic Liquids Using NMR and IR Spectroscopy: A General Chemistry Laboratory

    Science.gov (United States)

    Pavel, John T.; Hyde, Erin C.; Bruch, Martha D.

    2012-01-01

    This experiment introduced general chemistry students to the basic concepts of organic structures and to the power of spectroscopic methods for structure determination. Students employed a combination of IR and NMR spectroscopy to perform de novo structure determination of unknown alcohols, without being provided with a list of possible…

  20. The relationship between family orientation, organization context, organization structure and firm performance

    NARCIS (Netherlands)

    Meijaard, J.; Uhlaner, L.M.

    2004-01-01

    This study focuses on the prediction of three firm performance indicators, sales growth, innovation performance and profitability, on a sample of small and medium-sized firms in the Netherlands. Predictions from agency theory and the resource based view of organizations lead to alternate hypotheses

  1. Managing University IT Risks in Structured and Organized Environment

    Directory of Open Access Journals (Sweden)

    Sayef Sami Hassen

    2013-07-01

    Full Text Available In this digital era, most universities rely heavily on Information Technology (IT to process their information for better support of their visions and missions. However, with this reliance, IT is facing different types of risks under expansions and complexities as experienced by most universities these days. IT risk is not bounded to only information systems and security, but unbounded to encompass the risk to financial, strategic, technological, as well as reputational. All these types of risk are prevalent in universities and hence the need to implement an effective risk management process including but not limited to IT. The best opportunities for managing IT risks can be achieved through managing it within an integrated approach and not to be carried out separately from managing risks of the organization. Such approach ensures that IT is achieving the goals and objectives of the organization by providing a reasonable basis for strategic planning and improves decision making for top management based on risk management value. This study identifies the current implementation of risk management at one Malaysian university to face all risks. The main findings of this study are: (1 The majority of staff supports the fundamental objectives of risk management; (2 The necessity to improve and enhance some procedures of risk management at the university. This study provide recommendations and improvements in some procedures of risk management to increase the awareness of risk management among all the university staff.

  2. Structure of Solvent-Free Nanoparticle−Organic Hybrid Materials

    KAUST Repository

    Yu, Hsiu-Yu

    2010-11-16

    We derive the radial distribution function and the static structure factor for the particles in model nanoparticleorganic hybrid materials composed of nanoparticles and attached oligomeric chains in the absence of an intervening solvent. The assumption that the oligomers form an incompressible fluid of bead-chains attached to the particles that is at equilibrium for a given particle configuration allows us to apply a density functional theory for determining the equilibrium configuration of oligomers as well as the distribution function of the particles. A quasi-analytic solution is facilitated by a regular perturbation analysis valid when the oligomer radius of gyration R g is much greater than the particle radius a. The results show that the constraint that each particle carries its own share of the fluid attached to itself yields a static structure factor that approaches zero as the wavenumber approaches zero. This result indicates that each particle excludes exactly one other particle from its neighborhood. © 2010 American Chemical Society.

  3. Organization and structure of the mouse interleukin-2 gene.

    OpenAIRE

    Fuse, A; Fujita, T.; Yasumitsu, H; Kashima, N; Hasegawa, K; Taniguchi, T.

    1984-01-01

    We have cloned a chromosomal DNA segment which covers the entire sequence for the murine interleukin-2 gene and analysed the structure of the gene. The coding regions are separated into four blocks by three introns each of which is located similarly to the corresponding human gene. The exon sequences can be aligned perfectly with the previously cloned cDNA sequence. Of particular interests is the presence of sequences within the 5'-flanking region which are highly conserved between mouse and ...

  4. Transport anb Structural Properties of Aqueous Solutions of Organic Solvents.

    OpenAIRE

    Nieto Draghi, Carlos Eduardo

    2003-01-01

    Molecular Dynamics simulation technique has been used in this work to obtain equilibrium as well as transport properties of different aqueoussolutions. The peculiar behavior observed in pure water and its mixtures with other substances at different thermodynamic conditions, and the knowledge and understanding of the properties of these systems are the motivations of this work. We have made a direct connection between the local tetrahedral structure of water, created by the presence of hydroge...

  5. The Governance Structure and Performance of Agricultural Cooperative Economic Organizations in the Three Gorges Reservoir Area

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    On the basis of questionnaire survey results of 100 agricultural cooperative economic organizations in Three Gorges Reservoir Area,this article uses the structural equation modeling as analysis tool to conduct empirical analysis of the governance structure and performance of agricultural cooperative economic organizations. The results show that the ownership structure has the most critical impact on the performance of cooperative organizations,and the impact coefficient is as high as 0.92; the importance of oversight mechanism is basically equivalent to that of the council structure for cooperative organizations,and the impact coefficient is 0.87 and 0.86,respectively,second only to the ownership structure; the size of members’ quit capacity also has a very important impact on the performance of organizations,with impact coefficient of 0.74. Thus,the problems influencing the performance of organizations,in the current governance structure of agricultural cooperative economic organizations in Three Gorges Reservoir Area,are pointed out. Finally,corresponding countermeasures are put forward.

  6. Organization structure and the performance of hospital emergency services.

    Science.gov (United States)

    Georgopoulos, B S

    1985-07-01

    A comparative study of 30 hospital emergency departments (EDs) and nearly 1,500 individuals associated with them was conducted. Data were obtained from institutional records, physicians, patients, and other sources. The object was to investigate the relationship between the organization and performance of these health service systems. The study assessed the quality of medical care, the quality of nursing care, and the economic efficiency of hospital EDs. The results show substantial interinstitutional differences in these criteria. They also show a significant relationship between medical and nursing care, but not between the quality of care and economic efficiency. Differences in ED performance are related to medical staffing patterns, medical teaching affiliation, personnel training, scope of emergency services, number of patient visits processed, and hospital size and complexity. Not all of these variables, however, correlate positively with all three criteria of performance, nor are they equally important to each.

  7. Self-organization of punishment in structured populations

    CERN Document Server

    Perc, Matjaz

    2012-01-01

    Cooperation is crucial for the remarkable evolutionary success of the human species. Not surprisingly, some individuals are willing to bare additional costs in order to punish defectors. Current models assume that, once set, the fine and cost of punishment do not change over time. Here we show that relaxing this assumption by allowing players to adapt their sanctioning efforts in dependence on the success of cooperation can explain both, the spontaneous emergence of punishment, as well as its ability to deter defectors and those unwilling to punish them with globally negligible investments. By means of phase diagrams and the analysis of emerging spatial patterns, we demonstrate that adaptive punishment promotes public cooperation either through the invigoration of spatial reciprocity, the prevention of the emergence of cyclic dominance, or through the provision of competitive advantages to those that sanction antisocial behavior. Presented results indicate that the process of self-organization significantly e...

  8. Understanding Structure and Bonding of Multilayered Metal-Organic Nanostructures.

    Science.gov (United States)

    Egger, David A; Ruiz, Victor G; Saidi, Wissam A; Bučko, Tomáš; Tkatchenko, Alexandre; Zojer, Egbert

    2013-02-14

    For organic and hybrid electronic devices, the physicochemical properties of the contained interfaces play a dominant role. To disentangle the various interactions occurring at such heterointerfaces, we here model a complex, yet prototypical, three-component system consisting of a Cu-phthalocyanine (CuPc) film on a 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) monolayer adsorbed on Ag(111). The two encountered interfaces are similar, as in both cases there would be no bonding without van der Waals interactions. Still, they are also distinctly different, as only at the Ag(111)-PTCDA interface do massive charge-rearrangements occur. Using recently developed theoretical tools, we show that it has become possible to provide atomistic insight into the physical and chemical processes in this comparatively complex nanostructure distinguishing between interactions involving local rearrangements of the charge density and long-range van der Waals attraction. PMID:23447750

  9. Understanding Structure and Bonding of Multilayered Metal–Organic Nanostructures

    Science.gov (United States)

    2013-01-01

    For organic and hybrid electronic devices, the physicochemical properties of the contained interfaces play a dominant role. To disentangle the various interactions occurring at such heterointerfaces, we here model a complex, yet prototypical, three-component system consisting of a Cu–phthalocyanine (CuPc) film on a 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) monolayer adsorbed on Ag(111). The two encountered interfaces are similar, as in both cases there would be no bonding without van der Waals interactions. Still, they are also distinctly different, as only at the Ag(111)–PTCDA interface do massive charge-rearrangements occur. Using recently developed theoretical tools, we show that it has become possible to provide atomistic insight into the physical and chemical processes in this comparatively complex nanostructure distinguishing between interactions involving local rearrangements of the charge density and long-range van der Waals attraction. PMID:23447750

  10. Structure and organization of phospholipid/polysaccharide nanoparticles

    International Nuclear Information System (INIS)

    In recent years nanoparticles and microparticles composed of polymeric or lipid material have been proposed as drug carriers for improving the efficacy of encapsulated drugs. For the production of these systems different materials have been proposed, among them phospholipids and polysaccharides due to their biocompatibility, biodegradability, low cost and safety. We report here a morphological and structural investigation, performed using cryo-TEM, static light scattering and small angle neutron and x-ray scattering, on phospholipid/saccharide nanoparticles loaded with a lipophilic positively charged drug (tamoxifen citrate) used in breast cancer therapy. The lipid component was soybean lecithin; the saccharide one was chitosan that usually acts as an outer coating increasing vesicle stability. The microscopy and scattering data indicate the presence of two distinct nanoparticle families: uni-lamellar vesicles with average radius 90 A and multi-lamellar vesicles with average radius 440 A. In both families the inner core is occupied by the solvent. The presence of tamoxifen gives rise to a multi-lamellar structure of the lipid outer shell. It also induces a positive surface charge into the vesicles, repelling the positively charged chitosan molecules which therefore do not take part in nanoparticle formation

  11. Structure and organization of phospholipid/polysaccharide nanoparticles

    Science.gov (United States)

    Gerelli, Y.; Di Bari, M. T.; Deriu, A.; Cantù, L.; Colombo, P.; Como, C.; Motta, S.; Sonvico, F.; May, R.

    2008-03-01

    In recent years nanoparticles and microparticles composed of polymeric or lipid material have been proposed as drug carriers for improving the efficacy of encapsulated drugs. For the production of these systems different materials have been proposed, among them phospholipids and polysaccharides due to their biocompatibility, biodegradability, low cost and safety. We report here a morphological and structural investigation, performed using cryo-TEM, static light scattering and small angle neutron and x-ray scattering, on phospholipid/saccharide nanoparticles loaded with a lipophilic positively charged drug (tamoxifen citrate) used in breast cancer therapy. The lipid component was soybean lecithin; the saccharide one was chitosan that usually acts as an outer coating increasing vesicle stability. The microscopy and scattering data indicate the presence of two distinct nanoparticle families: uni-lamellar vesicles with average radius 90 Å and multi-lamellar vesicles with average radius 440 Å. In both families the inner core is occupied by the solvent. The presence of tamoxifen gives rise to a multi-lamellar structure of the lipid outer shell. It also induces a positive surface charge into the vesicles, repelling the positively charged chitosan molecules which therefore do not take part in nanoparticle formation.

  12. Structure and organization of phospholipid/polysaccharide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Gerelli, Y; Bari, M T Di; Deriu, A [Dipartimento di Fisica and CNISM, Universita degli Studi di Parma and CRS SOFT, INFM-CNR (Italy); Cantu, L [Dipartimento di Chimica, Biochimica e Biotecnologie per la Medicina-LITA, Universita di Milano (Italy); Colombo, P; Como, C; Motta, S; Sonvico, F [Dipartimento Farmaceutico, Universita degli Studi di Parma (Italy); May, R [Institut Laue-Langevin, Grenoble (France)], E-mail: Antonio.Deriu@fis.unipr.it

    2008-03-12

    In recent years nanoparticles and microparticles composed of polymeric or lipid material have been proposed as drug carriers for improving the efficacy of encapsulated drugs. For the production of these systems different materials have been proposed, among them phospholipids and polysaccharides due to their biocompatibility, biodegradability, low cost and safety. We report here a morphological and structural investigation, performed using cryo-TEM, static light scattering and small angle neutron and x-ray scattering, on phospholipid/saccharide nanoparticles loaded with a lipophilic positively charged drug (tamoxifen citrate) used in breast cancer therapy. The lipid component was soybean lecithin; the saccharide one was chitosan that usually acts as an outer coating increasing vesicle stability. The microscopy and scattering data indicate the presence of two distinct nanoparticle families: uni-lamellar vesicles with average radius 90 A and multi-lamellar vesicles with average radius 440 A. In both families the inner core is occupied by the solvent. The presence of tamoxifen gives rise to a multi-lamellar structure of the lipid outer shell. It also induces a positive surface charge into the vesicles, repelling the positively charged chitosan molecules which therefore do not take part in nanoparticle formation.

  13. Cleave to Leave : Structural Insights into the Dynamic Organization of the Nuclear Pore Complex

    NARCIS (Netherlands)

    Dokudovskaya, Svetlana; Veenhoff, Liesbeth M.; Rout, Michael P.

    2002-01-01

    A detailed understanding of the fine structure of the nuclear pore complex has remained elusive. Now, studies on a small protein domain have shed light on the dynamic organization of this massive assembly.

  14. Studies on structure and organization of calcium carbonate deposits in algae

    Digital Repository Service at National Institute of Oceanography (India)

    Kerkar, V.; Untawale, A.G.

    The structure and organization of calcium carbonate deposits is studied in species of Halimeda, Udotea, Neomeris (Chlorophyta) and Padina (Phaeophyta). It was found that in Halimeda aragonite deposition takes place outside the cell wall...

  15. Cloud motions on Venus - Global structure and organization

    Science.gov (United States)

    Limaye, S. S.; Suomi, V. E.

    1981-01-01

    Results on cloud motions on Venus obtained over a period of 3.5 days from Mariner 10 television images are presented. The implied atmosphere flow is almost zonal everywhere on the visible disk, and is in the same retrograde sense as the solid planet. Objective analysis of motions suggests the presence of jet cores (-130 m/s) and organized atmospheric waves. The longitudinal mean meridional profile of the zonal component of motion of the ultraviolet features shows presence of a midlatitude jet stream (-110 m/s). The mean zonal component is -97 m/s at the equator. The mean meridional motion at most latitudes is directed toward the pole in either hemisphere and is at least an order of magnitude smaller so that the flow is nearly zonal. A tentative conclusion from the limited coverage available from Mariner 10 is that at the level of ultraviolet features mean meridional circulation is the dominant mode of poleward angular momentum transfer as opposed to the eddy circulation.

  16. Self-organization of punishment in structured populations

    Science.gov (United States)

    Perc, Matjaž; Szolnoki, Attila

    2012-04-01

    Cooperation is crucial for the remarkable evolutionary success of the human species. Not surprisingly, some individuals are willing to bear additional costs in order to punish defectors. Current models assume that, once set, the fine and cost of punishment do not change over time. Here we show that relaxing this assumption by allowing players to adapt their sanctioning efforts in dependence on the success of cooperation can explain both the spontaneous emergence of punishment and its ability to deter defectors and those unwilling to punish them with globally negligible investments. By means of phase diagrams and the analysis of emerging spatial patterns, we demonstrate that adaptive punishment promotes public cooperation through the invigoration of spatial reciprocity, the prevention of the emergence of cyclic dominance, or the provision of competitive advantages to those that sanction antisocial behavior. The results presented indicate that the process of self-organization significantly elevates the effectiveness of punishment, and they reveal new mechanisms by means of which this fascinating and widespread social behavior could have evolved.

  17. Direct measurement of riverine particulate organic carbon age structure

    Science.gov (United States)

    Rosenheim, Brad E.; Galy, Valier

    2012-10-01

    Carbon cycling studies focusing on transport and transformation of terrigenous carbon sources toward marine sedimentary sinks necessitate separation of particulate organic carbon (OC) derived from many different sources and integrated by river systems. Much progress has been made on isolating and characterizing young biologically-formed OC that is still chemically intact, however quantification and characterization of old, refractory rock-bound OC has remained troublesome. Quantification of both endmembers of riverine OC is important to constrain exchanges linking biologic and geologic carbon cycles and regulating atmospheric CO2 and O2. Here, we constrain petrogenic OC proportions in suspended sediment from the headwaters of the Ganges River in Nepal through direct measurement using ramped pyrolysis radiocarbon analysis. The unique results apportion the biospheric and petrogenic fractions of bulk particulate OC and characterize biospheric OC residence time. Compared to the same treatment of POC from the lower Mississippi-Atchafalaya River system, contrast in age spectra of the Ganges tributary samples illustrates the difference between small mountainous river systems and large integrative ones in terms of the global carbon cycle.

  18. Organization of the ectodermal nervous structures in medusae: cubomedusae.

    Science.gov (United States)

    Eichinger, Justin M; Satterlie, Richard A

    2014-02-01

    At least two conducting systems are well documented in cubomedusae. A variably diffuse network of large neurons innervates the swim musculature and can be visualized immunohistochemically using antibodies against α- or β-tubulin. Despite the non-specificity of these antibodies, multiple lines of evidence suggest that staining highlights the primary motor networks. These networks exhibit unique neurite distributions among the muscle sheets in that network density is greatest in the perradial frenula, where neurites are oriented in parallel with radial muscle fibers. This highly innervated, buttress-like muscle sheet may serve a critical role in the cubomedusan mechanism of turning. In scyphomedusae, a second subumbrellar network immunoreactive to antibodies against the neuropeptide FMRFamide innervates the swim musculature, but it is absent in cubomedusae. Immunoreactivity to FMRFamide in cubomedusae is mostly limited to a small network of neurons in the pacemaker region of the rhopalia, the pedalial apex at the nerve ring junction, and a few neuron tracts in the nerve ring. However, FMRFamide-immunoreactive networks, as well as tubulin-immunoreactive networks, are nearly ubiquitous outside of the swim muscle sheets in the perradial smooth muscle bands, manubrium, pedalia, and tentacles. Here we describe in detail the peripheral nerve nets of box jellyfish on the basis of immunoreactivity to the antibodies above. Our results offer insight into how the peripheral nerve nets are organized to produce the complex swimming, feeding, and defensive behaviors observed in cubomedusae. PMID:24648206

  19. Microbial Mineralization of Soil Organic Matter: Role of Chemical Composition and Structural Organization

    Science.gov (United States)

    Khalaf, M. M. R.; Chilom, G.; Rice, J. A.

    2014-12-01

    The purpose of this study is to quantitatively assess the effect of organic matter self-assembly on its resistance to microbial mineralization. Humic acids isolated from leonardite, two peats and a mineral soil were used as organic matter samples because they provide a broad range of variability in terms of the origin and nature of their organic components. Using a solvent-based fractionation method, humic acid samples were disassembled into a humic-like component and a humic-lipid composite. The humic-lipid composite was further disassembled into an amphiphilic and a lipid component using an alkaline aqueous solution. Mixtures that reproduced the composition of self-assembled samples were prepared by mixing the solid individual fractions in the exact proportions that they were present in the original material. The original humic acids or their corresponding mixtures were added as the sole carbon source in separate aerobic cultures containing a microbial consortium isolated from a mineral soil. After incubation for 125 days mineralization of the self-assembled samples was shown to be higher by as much as 70% compared to their corresponding physical mixtures. The extent of mineralization of the self-assembled samples was not correlated to the material's chemical composition or hydrophobicity index obtained from their 13C solid-state NMR spectra. In contrast, mineralization of the physical mixtures and the individual fractions did vary with chemical composition and was accompanied by preferential mineralization of alkyl carbon. These results suggest the microbial mineralization of humic acids is related to their self-assembly.

  20. Metal-organic extended 2D structures: Fe-PTCDA on Au(111)

    OpenAIRE

    Álvarez, Lucía; Peláez, Samuel; Caillard, Renaud; Serena, Pedro A.; Martín-Gago, José A.; Méndez, Javier

    2010-01-01

    In this work we combine organic molecules of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) with iron atoms on an Au (111) substrate in ultra-high vacuum conditions at different temperatures. By means of scanning tunnelling microscopy (STM) we study the formation of stable 2D metal-organic structures. We show that at certain growth conditions (temperature, time and coverage) stable 'ladder-like' nanostructures are obtained. These are the result of connecting together two metal-organic c...

  1. Creating Structures for Network-Centric Warfare: Perspectives from Organization Theory

    OpenAIRE

    Sengupta, Kishore; Carl R. Jones

    1999-01-01

    1999 Command and Control Research and Technology Symposium (CCRTS), June 29 - July 1, 1999, U.S. Naval War College, Rhode Island Combat organizations are increasingly faced with the challenge to adapt to new and diverse engagements. The pace of change is being accelerated by advances in information technology. This article offers perspectives from organization theory that can serve as design principles for enabling combat organizations to adopt flexible structures to cope with cha...

  2. Structure and Morphology of Organic Semiconductor–Nanoparticle Hybrids Prepared by Soft Deposition

    OpenAIRE

    Banerjee, R.; Novák, J.; Drnec, J.; Yu, S.; Schreiber, F.; C. Frank; Girleanu, M.; Ersen, O.; Brinkmann, M.; Anger, F.; Lorch, C.; Dieterle, J; Gerlach, A.

    2015-01-01

    We present an extensive structural analysis of hybrid architectures prepared by the “soft” incorporation of gold nanoparticles (AuNPs) within an organic semiconductor matrix of diindenoperylene (DIP). Such “soft” or noninvasive deposition of nanoparticles within organic semiconducting host matrices not only minimizes the influence of the deposition process on the order and properties of the organic host molecules, but also offers additional control in the process of incorporation. The hybrid ...

  3. Structural and electronic properties of single molecules and organic layers on surfaces

    OpenAIRE

    Sotthewes, Kai

    2016-01-01

    Single molecules and organic layers on well-defined solid surfaces have attracted tremendous attention owing to their interesting physical and chemical properties. The ultimate utility of single molecules or self-assembled monolayers (SAMs) for potential applications is critically dependent on the structural, electronic and dynamic properties. Therefore is it important to study the structural and electronic properties as well as the dynamic processes of single molecules and organic layers on ...

  4. Automated torso organ segmentation from 3D CT images using structured perceptron and dual decomposition

    Science.gov (United States)

    Nimura, Yukitaka; Hayashi, Yuichiro; Kitasaka, Takayuki; Mori, Kensaku

    2015-03-01

    This paper presents a method for torso organ segmentation from abdominal CT images using structured perceptron and dual decomposition. A lot of methods have been proposed to enable automated extraction of organ regions from volumetric medical images. However, it is necessary to adjust empirical parameters of them to obtain precise organ regions. This paper proposes an organ segmentation method using structured output learning. Our method utilizes a graphical model and binary features which represent the relationship between voxel intensities and organ labels. Also we optimize the weights of the graphical model by structured perceptron and estimate the best organ label for a given image by dynamic programming and dual decomposition. The experimental result revealed that the proposed method can extract organ regions automatically using structured output learning. The error of organ label estimation was 4.4%. The DICE coefficients of left lung, right lung, heart, liver, spleen, pancreas, left kidney, right kidney, and gallbladder were 0.91, 0.95, 0.77, 0.81, 0.74, 0.08, 0.83, 0.84, and 0.03, respectively.

  5. Using Structure-Based Organic Chemistry Online Tutorials with Automated Correction for Student Practice and Review

    Science.gov (United States)

    O'Sullivan, Timothy P.; Hargaden, Gra´inne C.

    2014-01-01

    This article describes the development and implementation of an open-access organic chemistry question bank for online tutorials and assessments at University College Cork and Dublin Institute of Technology. SOCOT (structure-based organic chemistry online tutorials) may be used to supplement traditional small-group tutorials, thereby allowing…

  6. Body size and dispersal mode as key traits determining metacommunity structure of aquatic organisms

    NARCIS (Netherlands)

    De Bie, T.; De Meester, L.; Brendonck, L.; Martens, K.; Goddeeris, B.; Ercken, D.; Hampel, H.; Denys, L.; Vanhecke, L.; Van der Gucht, K.; Van Wichelen, J.; Vyverman, W.; Declerck, S.A.J.

    2012-01-01

    Relationships between traits of organisms and the structure of their metacommunities have so far mainly been explored with meta-analyses. We compared metacommunities of a wide variety of aquatic organism groups (12 groups, ranging from bacteria to fish) in the same set of 99 ponds to minimise biases

  7. Structuring the Administrative Organization of Local School Systems. Educational Research Service Circular No. 2.

    Science.gov (United States)

    American Association of School Administrators, Washington, DC.

    This paper is intended to assist school administrators in improving existing school organizations. It discusses the nature of organizations, provides indicators of reorganization timing, and discusses the task of reorganization. A matrix chart, used to analyze and compare different organizational structures, is provided with explanations.…

  8. The control structure of team-based organizations : A diagnostic model for empowerment

    NARCIS (Netherlands)

    Kuipers, Benjamin; de Witte, M.C.

    2005-01-01

    This article describes a diagnostic model for empowerment in team-based organizations that portrays four dimensions of the organization's control structure: the level of routine, the nature of expertise, the level of dependence and the line of command. The combined positions of the set of job regula

  9. Nanoencapsulation of Fullerenes in Organic Structures with Nonpolar Cavities

    Science.gov (United States)

    Murthy, C. N.

    2005-01-01

    The formation of supramolecular structures, assemblies, and arrays held together by weak intermolecular interactions and non-covalent binding mimicking natural processes has been used in applications being anticipated in nanotechnology, biotechnology and the emerging field of nanomedicine. Encapsulation of C60 fullerene by cyclic molecules like cyclodextrins and calixarenes has potential for a number of applications. Similarly, biomolecules like lysozyme also have been shown to encapsulate C60 fullerene. This poster article reports the recent trends and the results obtained in the nanoencapsulation of fullerenes by biomolecules containing nonpolar cavities. Lysozyme was chosen as the model biomolecule and it was observed that there is no covalent bond formed between the bimolecule and the C60 fullerene. This was confirmed from fluorescence energy transfer studies. UV Vis studies further supported this observation that it is possible to selectively remove the C60 fullerene from the nonpolar cavity. This behavior has potential in biomedical applications

  10. Internal structure analysis of particle-double network gels used in a gel organ replica

    Science.gov (United States)

    Abe, Mei; Arai, Masanori; Saito, Azusa; Sakai, Kazuyuki; Kawakami, Masaru; Furukawa, Hidemitsu

    2016-04-01

    In recent years, the fabrication of patient organ replicas using 3D printers has been attracting a great deal of attention in medical fields. However, the cost of these organ replicas is very high as it is necessary to employ very expensive 3D printers and printing materials. Here we present a new gel organ replica, of human kidney, fabricated with a conventional molding technique, using a particle-double network hydrogel (P-DN gel). The replica is transparent and has the feel of a real kidney. It is expected that gel organ replicas produced this way will be a useful tool for the education of trainee surgeons and clinical ultrasonography technologists. In addition to developing a gel organ replica, the internal structure of the P-DN gel used is also discussed. Because the P-DN gel has a complex structure comprised of two different types of network, it has not been possible to investigate them internally in detail. Gels have an inhomogeneous network structure. If it is able to get a more uniform structure, it is considered that this would lead to higher strength in the gel. In the present study we investigate the structure of P-DN gel, using the gel organ replica. We investigated the internal structure of P-DN gel using Scanning Microscopic Light Scattering (SMILS), a non-contacting and non-destructive.

  11. Applications of the Cambridge Structural Database in organic chemistry and crystal chemistry.

    Science.gov (United States)

    Allen, Frank H; Motherwell, W D Samuel

    2002-06-01

    The Cambridge Structural Database (CSD) and its associated software systems have formed the basis for more than 800 research applications in structural chemistry, crystallography and the life sciences. Relevant references, dating from the mid-1970s, and brief synopses of these papers are collected in a database, DBUse, which is freely available via the CCDC website. This database has been used to review research applications of the CSD in organic chemistry, including supramolecular applications, and in organic crystal chemistry. The review concentrates on applications that have been published since 1990 and covers a wide range of topics, including structure correlation, conformational analysis, hydrogen bonding and other intermolecular interactions, studies of crystal packing, extended structural motifs, crystal engineering and polymorphism, and crystal structure prediction. Applications of CSD information in studies of crystal structure precision, the determination of crystal structures from powder diffraction data, together with applications in chemical informatics, are also discussed.

  12. Molar crown inner structural organization in Javanese Homo erectus.

    Science.gov (United States)

    Zanolli, Clément

    2015-01-01

    This contribution investigates the inner organizational pattern (tooth tissue proportions and enamel-dentine junction morphology) of seven Homo erectus permanent molar crowns from the late Lower-early Middle Pleistocene Kabuh Formation of the Sangiran Dome (Central Java, Indonesia). The previous study of their external characteristics confirmed the degree of time-related structural reduction occurred in Javanese H. erectus, and also revealed a combination of nonmetric features which are rare in the Lower and early Middle Pleistocene dental record, but more frequently found in recent humans. In accordance with their outer occlusal morphology, the specimens exhibit a set of derived internal features, such as thick to hyperthick enamel, an incomplete expression of the crest patterns at the enamel-dentine junction (EDJ) level, a sharp EDJ topography. As a whole, these features differ from those expressed in some penecontemporaneous specimens/samples representing African H. erectus/ergaster and H. heidelbergensis, as well as in Neanderthals, but occur in recent human populations. Further research in virtual dental paleoanthropology to be developed at macroregional scale would clarify the polarity and intensity of the intermittent exchanges between continental and insular Southeast Asia around the Lower to Middle Pleistocene boundary, as well as should shed light on the still poorly understood longitudinal evolutionary dynamics across continental Asia. PMID:25209431

  13. Structure and Organization of the SWRL Drama and Public Speaking Program for 1972-73 Tryout.

    Science.gov (United States)

    Niedermeyer, Fred C.; And Others

    The structure and organization of the first four levels of the Southwest Regional Laboratory (SWRL) Drama and Public Speaking Program to be tried out in 1972-1973 are described in this paper. The program structure is defined in terms of skill, content, and assessment areas. Specific subareas of content are listed and are to be used to guide lesson…

  14. Near-unity mass accommodation coefficient of organic molecules of varying structure.

    Science.gov (United States)

    Julin, Jan; Winkler, Paul M; Donahue, Neil M; Wagner, Paul E; Riipinen, Ilona

    2014-10-21

    Atmospheric aerosol particles have a significant effect on global climate, air quality, and consequently human health. Condensation of organic vapors is a key process in the growth of nanometer-sized particles to climate relevant sizes. This growth is very sensitive to the mass accommodation coefficient α, a quantity describing the vapor uptake ability of the particles, but knowledge on α of atmospheric organics is lacking. In this work, we have determined α for four organic molecules with diverse structural properties: adipic acid, succinic acid, naphthalene, and nonane. The coefficients are studied using molecular dynamics simulations, complemented with expansion chamber measurements. Our results are consistent with α = 1 (indicating nearly perfect accommodation), regardless of the molecular structural properties, the phase state of the bulk condensed phase, or surface curvature. The results highlight the need for experimental techniques capable of resolving the internal structure of nanoparticles to better constrain the accommodation of atmospheric organics.

  15. Structural proteomics of minimal organisms: conservation ofprotein fold usage and evolutionary implications

    Energy Technology Data Exchange (ETDEWEB)

    Chandonia, John-Marc; Kim, Sung-Hou

    2006-03-15

    Background: Determining the complete repertoire of proteinstructures for all soluble, globular proteins in a single organism hasbeen one of the major goals of several structural genomics projects inrecent years. Results: We report that this goal has nearly been reachedfor several "minimal organisms"--parasites or symbionts with reducedgenomes--for which over 95 percent of the soluble, globular proteins maynow be assigned folds, overall 3-D backbone structures. We analyze thestructures of these proteins as they relate to cellular functions, andcompare conservation off old usage between functional categories. We alsocompare patterns in the conservation off olds among minimal organisms andthose observed between minimal organisms and other bacteria. Conclusion:We find that proteins performing essential cellular functions closelyrelated to transcription and translation exhibit a higher degree ofconservation in fold usage than proteins in other functional categories.Folds related to transcription and translation functional categories werealso over represented in minimal organisms compared to otherbacteria.

  16. The organization of heart services. Part Two: Structural alternatives for the successful heart services organization.

    Science.gov (United States)

    Ronning, P L; Beveridge, R N

    1994-01-01

    This article provides a framework of the various models currently available to form a heart institute that is designed to enhance the position of the providers with managed care and other third-party payers. Each model has components that are similar: Governance and management are provided by an advisory board or steering committee. The board is typically comprised of representatives of both the physicians and the hospital. Daily management is provided by a professional manager, such as an executive director. The ability of the model to locate, negotiate and enter into contracts for the providers is determined by the amount of integration of services provided by the participants. Each of the models discussed in sequence represents increasing integration; therefore, the cardiac IPO has more integration--particularly if it offers a new service such as capitation to the market--than the service-line approach. The ICHO has the most integration of the models presented. This form of organization will be addressed more completely in Part Four of this series. Part Three will discuss PHO models in-depth as well as address certain legal requirements that should be considered when developing a new, integrated PHO entity. PMID:10136759

  17. Studying of shale organic matter structure and pore space transformations during hydrocarbon generation

    Science.gov (United States)

    Giliazetdinova, Dina; Korost, Dmitry; Gerke, Kirill

    2016-04-01

    Due to the increased interest in the study of the structure, composition, and oil and gas potential of unconventional hydrocarbon resources, investigations of the transformation of the pore space of rocks and organic matter alterations during the generation of hydrocarbon fluids are getting attention again. Due to the conventional hydrocarbon resources decreasing, there will be a necessity to develop new unconventional hydrocarbon resources. Study of the conditions and processes of hydrocarbon generation, formation and transformation of the pore space in these rocks is pivotal to understand the mechanisms of oil formation and determine the optimal and cost effective ways for their industrial exploration. In this study, we focus on organic matter structure and its interaction with the pore space of shales during hydrocarbon generation and report some new results. Collected rock samples from Domanic horizon of South-Tatar arch were heated in the pyrolyzer to temperatures closely corresponding to different catagenesis stages. X-ray microtomography method and SEM were used to monitor changes in the morphology of the pore space and organic matter structure within studied shale rocks. By routine measurements we made sure that all samples (10 in total) had similar composition of organic and mineral phases. All samples in the collection were grouped according to initial structure and amount of organics and processed separately to: 1) study the influence of organic matter content on the changing morphology of the rock under thermal effects; 2) study the effect of initial structure on the primary migration processes for samples with similar organic matter content. An additional experiment was conducted to study the dynamics of changes in the structure of the pore space and prove the validity of our approach. At each stage of heating the morphology of altered rocks was characterized by formation of new pores and channels connecting primary voids. However, it was noted that

  18. An investigation on a production company via the scope of Mintzberg’s adhocratic organization structure

    Directory of Open Access Journals (Sweden)

    Kerem Toker

    2013-01-01

    Full Text Available Today, the importance of innovation for enterprises, increase each passing day. As a result of globalization, enterprises are under intense competitive pressure. They have to make innovation for increasing to market share or for protecting to it at least. Non-innovative firms lose their customers and their existence is face to threat from other innovative actors in the market. Therefore firms have to design their organization structure that encourage to innovation. Mintzberg’s adhocratic organization structure was investigated in this article.  Thus, its aim of this study leads to resemblance and diversity between theory and practice via of the theoretical knowledge.  As a result of study; high degree of similarity between the application and Mintzberg’s theory, which is related to adhocratic organization structure, has been identified.Keywords: Innovation, Organizational Structure, Mintzberg, Adhocracy, Media Sector

  19. Hydrophobic core/hydrophilic shell structured mesoporous silica nanospheres: enhanced adsorption of organic compounds from water.

    Science.gov (United States)

    Li, Shuru; Jiao, Xuan; Yang, Hengquan

    2013-01-29

    Inspired by the structure features of micelle, we attempt to synthesize a novel functionalized mesoporous silica nanosphere consisting of a hydrophobic core and a hydrophilic shell. The obtained solid materials were structurally confirmed by N(2) sorption, X-ray diffraction (XRD), and transmission electron microscopy (TEM). Their compositions were characterized by Fourier transfer infrared spectroscopy (FT-IR), solid state NMR, X-ray photoelectron spectroscopy (XPS), and elemental analysis. Its fundamental properties such as dispersibility in water or organic phase, wettability, and adsorption ability toward hydrophobic organics in water were investigated. It was revealed that these important properties could be facilely adjusted through varying structure and composition. In particular, these materials showed much better adsorption ability toward hydrophobic organic molecules in water than conventional monofunctionalized mesoporous materials, owing to possessing the hydrophobic/hydrophilic domain-segregated and hierarchically functionalized mesoporous structures. The intriguing properties would make mesoporous materials more accessible to many important applications, especially in aqueous systems.

  20. Investigation of Multilayer Organic Insulation Structure on Surface Flashover Properties and Mechanism in Vacuum

    Institute of Scientific and Technical Information of China (English)

    LI Shengtao; HUANG Qifeng

    2013-01-01

    In order to further investigate the surface flashover mechanism in vacuum,the surface flashover and electric field distribution of multilayer organic insulation structure are studied and developed based on the previous studies.The samples ofmultilayer organic insulation structure are prepared by inserting multilayer organic composite material with different relative permittivity between the electrode and the dielectric.Two multilayer organic insulation structures are prepared in this study.One is the cylindrical samples,the other is 45° samples.The impulse (1.2/50 μs) and DC flashover voltages in vacuum are tested,and the electric field distributions of two insulation structures are analyzed by ANSYS.It is found that these two insulation structure could effectively improve the surface flashover performance in vacuum.The results indicate that the highest impulse first flashover voltage of cylindrical samples reaches 65 kV and increases by 25% under impulse voltage.The highest first flashover voltage of/c samples reaches 81 kV and increases by 32% under impulse voltage.The results of electric field simulation demonstrate that different mechanisms exist between 45° insulation structure and cylindrical structure.

  1. Parameterizing liquid crystal variable retarder structural organization with a fractal-Born approximation model

    Science.gov (United States)

    Gladish, James C.; Duncan, Donald D.

    2016-05-01

    Liquid crystal variable retarders (LCVRs) are computer-controlled birefringent devices that contain nanometer-sized birefringent liquid crystals (LCs). These devices impart retardance effects through a global, uniform orientation change of the LCs, which is based on a user-defined drive voltage input. In other words, the LC structural organization dictates the device functionality. The LC structural organization also produces a spectral scatter component which exhibits an inverse power law dependence. We investigate LC structural organization by measuring the voltage-dependent LC spectral scattering signature with an integrating sphere and then relate this observable to a fractal-Born model based on the Born approximation and a Von Kármán spectrum. We obtain LCVR light scattering spectra at various drive voltages (i.e., different LC orientations) and then parameterize LCVR structural organization with voltage-dependent correlation lengths. The results can aid in determining performance characteristics of systems using LCVRs and can provide insight into interpreting structural organization measurements.

  2. The Impact of the Demand for Integration in the Large Multi-Business Unit Firm on the IT Organization Structure

    Science.gov (United States)

    Larson, Eric Christopher

    2012-01-01

    Large, multi-business unit firms are decentralizing their overall corporate structures. At the same time, the structures of their IT organizations are becoming more centralized. This is contrary to current wisdom that the IT organization structure will mimic the structure of the corporation, all else being equal. Because the general business…

  3. Studying the operation characteristics and structure of vertical channel copper-phthalocyanine organic semiconductor transistor

    Institute of Scientific and Technical Information of China (English)

    ZHU Min; SONG Ming-xin; GUI Tai-long; WANG Xuan; YIN Jing-hua; WANG Dong-xing; ZHAO Hong

    2005-01-01

    The creation of Au/CuPc/Al/CuPc/structure is a perpendicular type electricity found in the channel of organic static induction transistor. In the following we analyze transistor operation characteristics and machine structural relation. The results express that the transistor drives the voltage low and has no-saturation currentvoltage characteristics. Its operation characteristics are dependant on gate bias voltage and the construction of the aluminum electrode.The vertical channel of organic static induction transistor (OSIT) , with structure of Au/CuPc/Al/CuPc/Cu, has been determined. According to the test results, the relation of its operation characteristics and device structure was analyzed. The results show that this transistor has a low driving voltage and unsaturation Ⅰ-Ⅴ characteristics. Its operation characteristics are dependant on gate bias voltage and the structure of the aluminum electrode.

  4. Organic chemistry as a language and the implications of chemical linguistics for structural and retrosynthetic analyses.

    Science.gov (United States)

    Cadeddu, Andrea; Wylie, Elizabeth K; Jurczak, Janusz; Wampler-Doty, Matthew; Grzybowski, Bartosz A

    2014-07-28

    Methods of computational linguistics are used to demonstrate that a natural language such as English and organic chemistry have the same structure in terms of the frequency of, respectively, text fragments and molecular fragments. This quantitative correspondence suggests that it is possible to extend the methods of computational corpus linguistics to the analysis of organic molecules. It is shown that within organic molecules bonds that have highest information content are the ones that 1) define repeat/symmetry subunits and 2) in asymmetric molecules, define the loci of potential retrosynthetic disconnections. Linguistics-based analysis appears well-suited to the analysis of complex structural and reactivity patterns within organic molecules.

  5. Types of Complementarity, Combinative Organization Forms and Structural Heterogeneity: Beyond Discrete Structural Alternatives

    OpenAIRE

    Grandori, A.; FURNARI, S.

    2009-01-01

    In recent years, applied studies have shown widespread, profound and increasing heterogeneity across firms in terms of their strategy, organization arrangement and performance. This book investigates the diversity of business firms, offering a picture of the different organizational settings they adopt in their endeavour to cope with increasing competitive pressure.

  6. The role of the organization structure in the diffusion of innovations.

    Directory of Open Access Journals (Sweden)

    Carlos Sáenz-Royo

    Full Text Available Diffusion and adoption of innovations is a topic of increasing interest in economics, market research, and sociology. In this paper we investigate, through an agent based model, the dynamics of adoption of innovative proposals in different kinds of structures. We show that community structure plays an important role on the innovation diffusion, so that proposals are more likely to be accepted in homogeneous organizations. In addition, we show that the learning process of innovative technologies enhances their diffusion, thus resulting in an important ingredient when heterogeneous networks are considered. We also show that social pressure blocks the adoption process whatever the structure of the organization. These results may help to understand how different factors influence the diffusion and acceptance of innovative proposals in different communities and organizations.

  7. An Investigation on a Production Company via the Scope of Mintzberg’s Adhocratic Organization Structure

    Directory of Open Access Journals (Sweden)

    Yasin Cakirel

    2016-01-01

    Full Text Available Today, the importance of innovation for enterprises, increase each passing day. As a result of globalization, enterprises are under intense competitive pressure. They have to make innovation for increasing to market share or for protecting to it at least. Noninnovative firms lose their customers and their existence is face to threat from other innovative actors in the market. Therefore firms have to design their organization structure that encourage to innovation. Mintzberg’s adhocratic organization structure was investigated in this article. Thus, its aim of this study leads to resemblance and diversity between theory and practice via of the theoretical knowledge. As a result of study; high degree of similarity between the application and Mintzberg’s theory, which is related to adhocratic organization structure, has been identified.

  8. The role of the organization structure in the diffusion of innovations.

    Science.gov (United States)

    Sáenz-Royo, Carlos; Gracia-Lázaro, Carlos; Moreno, Yamir

    2015-01-01

    Diffusion and adoption of innovations is a topic of increasing interest in economics, market research, and sociology. In this paper we investigate, through an agent based model, the dynamics of adoption of innovative proposals in different kinds of structures. We show that community structure plays an important role on the innovation diffusion, so that proposals are more likely to be accepted in homogeneous organizations. In addition, we show that the learning process of innovative technologies enhances their diffusion, thus resulting in an important ingredient when heterogeneous networks are considered. We also show that social pressure blocks the adoption process whatever the structure of the organization. These results may help to understand how different factors influence the diffusion and acceptance of innovative proposals in different communities and organizations.

  9. Metal-organic extended 2D structures: Fe-PTCDA on Au(111).

    Science.gov (United States)

    Alvarez, Lucía; Peláez, Samuel; Caillard, Renaud; Serena, Pedro A; Martín-Gago, José A; Méndez, Javier

    2010-07-30

    In this work we combine organic molecules of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) with iron atoms on an Au (111) substrate in ultra-high vacuum conditions at different temperatures. By means of scanning tunnelling microscopy (STM) we study the formation of stable 2D metal-organic structures. We show that at certain growth conditions (temperature, time and coverage) stable 'ladder-like' nanostructures are obtained. These are the result of connecting together two metal-organic chains through PTCDA molecules placed perpendicularly, as rungs of a ladder. These structures, stable up to 450 K, can be extended in a 2D layer covering the entire surface and presenting different rotation domains. STM images at both polarities show a contrast reversal between the two molecules at the unit cell. By means of density functional theory (DFT) calculations, we confirm the stability of these structures and that their molecular orbitals are placed separately at the different molecules. PMID:20603531

  10. Metal-organic extended 2D structures: Fe-PTCDA on Au(111)

    International Nuclear Information System (INIS)

    In this work we combine organic molecules of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) with iron atoms on an Au (111) substrate in ultra-high vacuum conditions at different temperatures. By means of scanning tunnelling microscopy (STM) we study the formation of stable 2D metal-organic structures. We show that at certain growth conditions (temperature, time and coverage) stable 'ladder-like' nanostructures are obtained. These are the result of connecting together two metal-organic chains through PTCDA molecules placed perpendicularly, as rungs of a ladder. These structures, stable up to 450 K, can be extended in a 2D layer covering the entire surface and presenting different rotation domains. STM images at both polarities show a contrast reversal between the two molecules at the unit cell. By means of density functional theory (DFT) calculations, we confirm the stability of these structures and that their molecular orbitals are placed separately at the different molecules.

  11. Metal-organic frameworks: structure, properties, methods of synthesis and characterization

    Science.gov (United States)

    Butova, V. V.; Soldatov, M. A.; Guda, A. A.; Lomachenko, K. A.; Lamberti, C.

    2016-03-01

    This review deals with key methods of synthesis and characterization of metal-organic frameworks (MOFs). The modular structure affords a wide variety of MOFs with different active metal sites and organic linkers. These compounds represent a new stage of development of porous materials in which the pore size and the active site structure can be modified within wide limits. The set of experimental methods considered in this review is sufficient for studying the short-range and long-range order of the MOF crystal structure, determining the morphology of samples and elucidating the processes that occur at the active metal site in the course of chemical reactions. The interest in metal-organic frameworks results, first of all, from their numerous possible applications, ranging from gas separation and storage to chemical reactions within the pores. The bibliography includes 362 references.

  12. Correlating Molecular Structures with Transport Dynamics in High-Efficiency Small-Molecule Organic Photovoltaics.

    Science.gov (United States)

    Peng, Jiajun; Chen, Yani; Wu, Xiaohan; Zhang, Qian; Kan, Bin; Chen, Xiaoqing; Chen, Yongsheng; Huang, Jia; Liang, Ziqi

    2015-06-24

    Efficient charge transport is a key step toward high efficiency in small-molecule organic photovoltaics. Here we applied time-of-flight and organic field-effect transistor to complementarily study the influences of molecular structure, trap states, and molecular orientation on charge transport of small-molecule DRCN7T (D1) and its analogue DERHD7T (D2). It is revealed that, despite the subtle difference of the chemical structures, D1 exhibits higher charge mobility, the absence of shallow traps, and better photosensitivity than D2. Moreover, charge transport is favored in the out-of-plane structure within D1-based organic solar cells, while D2 prefers in-plane charge transport.

  13. Metal-organic extended 2D structures: Fe-PTCDA on Au(111)

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, Lucia; Caillard, Renaud; MartIn-Gago, Jose A; Mendez, Javier [Grupo ESISNA, Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas (CSIC), c/ Sor Juana Ines de la Cruz 3, Campus de Cantoblanco, E-28049 Madrid (Spain); Pelaez, Samuel; Serena, Pedro A, E-mail: jmendez@icmm.csic.es [Grupo de Teoria y Simulacion de Materiales, Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas (CSIC), c/ Sor Juana Ines de la Cruz 3, Campus de Cantoblanco, E-28049 Madrid (Spain)

    2010-07-30

    In this work we combine organic molecules of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) with iron atoms on an Au (111) substrate in ultra-high vacuum conditions at different temperatures. By means of scanning tunnelling microscopy (STM) we study the formation of stable 2D metal-organic structures. We show that at certain growth conditions (temperature, time and coverage) stable 'ladder-like' nanostructures are obtained. These are the result of connecting together two metal-organic chains through PTCDA molecules placed perpendicularly, as rungs of a ladder. These structures, stable up to 450 K, can be extended in a 2D layer covering the entire surface and presenting different rotation domains. STM images at both polarities show a contrast reversal between the two molecules at the unit cell. By means of density functional theory (DFT) calculations, we confirm the stability of these structures and that their molecular orbitals are placed separately at the different molecules.

  14. Family Structure as a Correlate of Organized Sport Participation among Youth.

    Directory of Open Access Journals (Sweden)

    Rachel McMillan

    Full Text Available Organized sport is one way that youth participate in physical activity. There are disparities in organized sport participation by family-related factors. The purpose of this study was to determine whether non-traditional family structure and physical custody arrangements are associated with organized sport participation in youth, and if so whether this relationship is mediated by socioeconomic status. Data were from the 2009-10 Health Behaviour in School-aged Children survey, a nationally representative cross-section of Canadian youth in grades 6-10 (N = 21,201. Information on family structure was derived from three survey items that asked participants the number of adults they lived with, their relationship to these adults, and if applicable, how often they visited another parent outside their home. Participants were asked whether or not they were currently involved in an organized sport. Logistic regression was used to compare the odds of organized sport participation according to family structure. Bootstrap-based mediation analysis was used to assess mediation by perceived family wealth. The results indicated that by comparison to traditional families, boys and girls from reconstituted families with irregular visitation of a second parent, reconstituted families with regular visitation of a second parent, single-parent families with irregular visitation of a second parent, and single-parent families with regular visitation of a second parent were less likely to participate in organized sport than those from traditional families, with odds ratios ranging from 0.48 (95% confidence interval: 0.38-0.61 to 0.78 (95% confidence interval: 0.56-1.08. The relationship between family structure and organized sport was significantly mediated by perceived family wealth, although the magnitude of the mediation was modest (ie, <20% change in effect estimate. In conclusion, youth living in both single-parent and reconstituted families experienced significant

  15. A German survey on structure and developments of anaerobic digestion in organic farming systems

    OpenAIRE

    Benjamin Blumenstein; Torsten Siegmeier; Carsten Bruckhaus; Victor Anspach; Detlev Möller

    2015-01-01

    Rising global energy needs and limited fossil fuel reserves have led to increased use of renewable energies. In Germany, this has entailed massive exploitation of agricultural biomass for biogas generation, associated with unsustainable farming practices. Organic agriculture not only reduces negative environmental impacts, organic farmers were also prime movers in anaerobic digestion (AD) in Germany. This study’s aim was to identify the structure, development, and characteristics of biogas pr...

  16. Synthesis, structure, and opto-electronic properties of organic-based nanoscale heterojunctions

    OpenAIRE

    Cimrová Vĕra; Rezek Bohuslav; Čermák Jan; Kromka Alexander; Ledinský Martin; Hubík Pavel; Mareš Jiří; Purkrt Adam; Fejfar Antonín; Kočka Jan

    2011-01-01

    Abstract Enormous research effort has been put into optimizing organic-based opto-electronic systems for efficient generation of free charge carriers. This optimization is mainly due to typically high dissociation energy (0.1-1 eV) and short diffusion length (10 nm) of excitons in organic materials. Inherently, interplay of microscopic structural, chemical, and opto-electronic properties plays crucial role. We show that employing and combining advanced scanning probe techniques can provide us...

  17. Confirmation of the Dimensional Adjustment Model of Organizational Structure in Municipal Sports Organizations

    Directory of Open Access Journals (Sweden)

    Sofia Nikolaidou

    2015-09-01

    Full Text Available The presence of municipal sport organizations indicates the priority, which is given from the local authority in the well-being of citizens. On the other hand, it constitutes the basis upon which sports are built in national level. The whole body of the organizations has an organizational structure. The organizational structure is a system of registration of employment and the relations that govern them. The basic dimensions are: concentration, complexity and formalization. The purpose of this study is to confirm or contradict the proposed, based on the literature, model of organizational structure in municipal sports organizations. The Sport Commission Organization Structure Survey questionnaire was used in order to conduct it. The participants were 100 Greek municipal sport organizations. Factor analysis detected four factors: departmentalization, concentration, specialization and formalization. The results confirmed partially the proposed model. The ‘Cronbach a’ was used to calculate the reliability factors ranged from .40 to .70. The confirmatory factor analysis was used to determine the adjustment or not to the new model in the data. Based on the model of the confirmatory factor analysis it is revealed that it was slightly acceptable. Finally, although there was a marginal confirmation of the new model, it appears that questions of this survey require further improvement.

  18. Structural characterization of wind-sheared turbulent flow using self-organized mapping

    Science.gov (United States)

    Scott, Nicholas V.; Handler, Robert A.

    2016-05-01

    A nonlinear cluster analysis algorithm is used to characterize the spatial structure of a wind-sheared turbulent flow obtained from the direct numerical simulation (DNS) of the three-dimensional temperature and momentum fields. The application of self-organizing mapping to DNS data for data reduction is utilized because of the dimensional similitude in structure between DNS data and remotely sensed hyperspectral and multispectral data where the technique has been used extensively. For the three Reynolds numbers of 150, 180, and 220 used in the DNS, self-organized mapping is successful in the extraction of boundary layer streaky structures from the turbulent temperature and momentum fields. In addition, it preserves the cross-wind scale structure of the streaks exhibited in both fields which loosely scale with the inverse of the Reynolds number. Self-organizing mapping of the along wind component of the helicity density shows a layer of the turbulence field which is spotty suggesting significant direct coupling between the large and small-scale turbulent structures. The spatial correlation of the temperature and momentum fields allows for the possibility of the remote extrapolation of the momentum structure from thermal structure.

  19. Implementation of submicrometric periodic surface structures toward improvement of organic-solar-cell performances

    Science.gov (United States)

    Cocoyer, C.; Rocha, L.; Sicot, L.; Geffroy, B.; de Bettignies, R.; Sentein, C.; Fiorini-Debuisschert, C.; Raimond, P.

    2006-03-01

    Submicrometric periodic patterning of an organic solar cell surface is investigated in order to optimize the photovoltaic conversion efficiency of the device. Patterning is achieved using a single-step all-optical technique based on photoinduced mass transport in azopolymer films. The polymer film with a structured surface is used as a substrate for an organic solar cell based on a copper phthalocyanine/C60 heterojunction. The effect of periodic patterning is investigated through the solar-cell optical-absorption properties and external quantum efficiency measurements. The possibility to increase the short circuit current density and the corresponding photovoltaic conversion efficiency is evidenced with one-dimensional periodic structures.

  20. Organic structure determination using 2-D NMR spectroscopy a problem-based approach

    CERN Document Server

    Simpson, Jeffrey H

    2011-01-01

    Organic Structure Determination Using 2-D NMR Spectroscopy: A Problem-Based Approach, Second Edition, provides an introduction to the use of two-dimensional (2-D) nuclear magnetic resonance (NMR) spectroscopy to determine organic structure. The book begins with a discussion of the NMR technique, while subsequent chapters cover instrumental considerations; data collection, processing, and plotting; chemical shifts; symmetry and topicity; through-bond effects; and through-space effects. The book also covers molecular dynamics; strategies for assigning resonances to atoms within a molecule; s

  1. Autonomy and structure can enhance motivation of volunteers in sport organizations.

    Science.gov (United States)

    Hsu, Wei Ting; Wu, Kou Hsien; Wang, Yi Ching; Hsiao, Chia Huei; Wu, Hui Chin

    2013-12-01

    The goal was better understanding of the motivational factors of volunteers in non-profit sport organizations. The roles of two factors provided by supervisors to their subordinates were examined: autonomy support, i.e., the encouragement of self-initiation and emphasis on choice rather than control, and structure, i.e., the introduction of order, definite procedures, and rules. 489 sport volunteers (289 men, 200 women; M age = 31.2 yr., SD = 7.4) were administered questionnaires assessing their perceived autonomy support, structure, and motivation. Regression analysis indicated that perceived autonomy support predicted motivation. Structure also mediated the effect of perceived autonomy support on motivation. Supervisors of sport organizations should provide adequate structure for their volunteers.

  2. Family Structure as a Correlate of Organized Sport Participation among Youth.

    Science.gov (United States)

    McMillan, Rachel; McIsaac, Michael; Janssen, Ian

    2016-01-01

    Organized sport is one way that youth participate in physical activity. There are disparities in organized sport participation by family-related factors. The purpose of this study was to determine whether non-traditional family structure and physical custody arrangements are associated with organized sport participation in youth, and if so whether this relationship is mediated by socioeconomic status. Data were from the 2009-10 Health Behaviour in School-aged Children survey, a nationally representative cross-section of Canadian youth in grades 6-10 (N = 21,201). Information on family structure was derived from three survey items that asked participants the number of adults they lived with, their relationship to these adults, and if applicable, how often they visited another parent outside their home. Participants were asked whether or not they were currently involved in an organized sport. Logistic regression was used to compare the odds of organized sport participation according to family structure. Bootstrap-based mediation analysis was used to assess mediation by perceived family wealth. The results indicated that by comparison to traditional families, boys and girls from reconstituted families with irregular visitation of a second parent, reconstituted families with regular visitation of a second parent, single-parent families with irregular visitation of a second parent, and single-parent families with regular visitation of a second parent were less likely to participate in organized sport than those from traditional families, with odds ratios ranging from 0.48 (95% confidence interval: 0.38-0.61) to 0.78 (95% confidence interval: 0.56-1.08). The relationship between family structure and organized sport was significantly mediated by perceived family wealth, although the magnitude of the mediation was modest (ie, sport participation that was partially mediated by perceived family wealth.

  3. Impact of Structures on Knowledge Contribution in Virtual Organizations: The Asian Case

    OpenAIRE

    Xi Zhang

    2011-01-01

    As multi-culture virtual teams become more prevalent in organizations, it becomes increasingly imperative to understand knowledge sharing dynamics. This paper uses Adaptive Structuration Theory extended to address proactive structuration as a foundation from which a model is developed to include aspects of knowledge sharing. Propositions are established, and evidence is provided based on a project involving 119 participants comprising 13 teams of nominally nine members. Each team was composed...

  4. Enhanced photoluminescence from self-organized rubrene single crystal surface structures

    Science.gov (United States)

    Stöhr, R. J.; Beirne, G. J.; Michler, P.; Scholz, R.; Wrachtrup, J.; Pflaum, J.

    2010-06-01

    We report on crystalline pyramidal structures grown via self-organization on the rubrene (001) surface. The analysis of their spectral response by means of photoluminescence with micrometer lateral resolution reveals an intensity enhancement on-top of the surface structures. As we demonstrate this intensity increase can be related to the excitation processes at the molecular level in combination with exciton confinement within the pyramids.

  5. Polyrhythmic Tapping: Examining the Effectiveness of the Strategy of Organizing Rhythmic Structures through Synthesis

    Science.gov (United States)

    Yokus, Hamit; Yokus, Tuba

    2015-01-01

    In this study the strategy of organizing rhythmic structures through synthesis is named, and defined, and its procedures are described. Its effectiveness for teaching the execution of 3:2, 4:3, 8:3, 5:4, and 3:5 polyrhythmic structures is examined and described. Pre-test and Post-test Control Group Design was employed to test the effectiveness of…

  6. Electrochemical properties of honeycomb-like structured HFBI self-organized membranes on HOPG electrodes.

    Science.gov (United States)

    Yamasaki, Ryota; Takatsuji, Yoshiyuki; Lienemann, Michael; Asakawa, Hitoshi; Fukuma, Takeshi; Linder, Markus; Haruyama, Tetsuya

    2014-11-01

    HFBI (derived from Trichoderma sp.) is a unique structural protein, which forms a self-organized monolayer at both air/water interface and water/solid interfaces in accurate two-dimensional ordered structures. We have taken advantage of the unique functionality of HFBI as a molecular carrier for preparation of ordered molecular phase on solid substrate surfaces. The HFBI molecular carrier can easily form ordered structures; however, the dense molecular layers form an electrochemical barrier between the electrode and solution phase. In this study, the electrochemical properties of HFBI self-organized membrane-covered electrodes were investigated. Wild-type HFBI has balanced positive and negative charges on its surface. Highly oriented pyrolytic graphite (HOPG) electrodes coated with HFBI molecules were investigated electrochemically. To improve the electrochemical properties of this HFBI-coated electrode, the two types of HFBI variants, with oppositely charged surfaces, were prepared genetically. All three types of HFBI-coated HOPG electrode perform electron transfer between the electrode and solution phase through the dense HFBI molecular layer. This is because the HFBI self-organized membrane has a honeycomb-like structure, with penetrating holes. In the cases of HFBI variants, the oppositely charged HFBI membrane phases shown opposite electrochemical behaviors in electrochemical impedance spectroscopy. HFBI is a molecule with a unique structure, and can easily form honeycomb-like structures on solid material surfaces such as electrodes. The molecular membrane phase can be used for electrochemical molecular interfaces.

  7. Water Dynamics and Its Role in Structural Hysteresis of Dissolved Organic Matter.

    Science.gov (United States)

    Conte, Pellegrino; Kucerik, Jiri

    2016-03-01

    Knowledge of structural dynamics of dissolved organic matter (DOM) is of paramount importance for understanding DOM stability and role in the fate of solubilized organic and inorganic compounds (e.g., nutrients and pollutants), either in soils or aquatic systems. In this study, fast field cycling (FFC) (1)H NMR relaxometry was applied to elucidate structural dynamics of terrestrial DOM, represented by two structurally contrasting DOM models such as Suwanee River (SRFA) and Pahokee peat (PPFA) fulvic acids purchased by the International Humic Substance Society. Measurement of NMR relaxation rate of water protons in heating-cooling cycles revealed structural hysteresis in both fulvic acids. In particular, structural hysteresis was related to the delay in re-establishing water network around fulvic molecules as a result of temperature fluctuations. The experiments revealed that the structural temperature dependency and hysteresis were more pronounced in SRFA than in PPFA. This was attributed to the larger content of hydrogel-like structure in SRFA stabilized, at a larger extent, by H-bonds between carboxylic and phenolic groups. Moreover, results supported the view that terrestrial DOM consist of a hydrophobic rigid core surrounded by progressively assembling amphiphilic and polar molecules, which form an elastic structure that can mediate reactivity of the whole DOM.

  8. Teachers' Organization of Participation Structures for Teaching Science with Computer Technology

    Science.gov (United States)

    Subramaniam, Karthigeyan

    2016-02-01

    This paper describes a qualitative study that investigated the nature of the participation structures and how the participation structures were organized by four science teachers when they constructed and communicated science content in their classrooms with computer technology. Participation structures focus on the activity structures and processes in social settings like classrooms thereby providing glimpses into the complex dynamics of teacher-students interactions, configurations, and conventions during collective meaning making and knowledge creation. Data included observations, interviews, and focus group interviews. Analysis revealed that the dominant participation structure evident within participants' instruction with computer technology was (Teacher) initiation-(Student and Teacher) response sequences-(Teacher) evaluate participation structure. Three key events characterized the how participants organized this participation structure in their classrooms: setting the stage for interactive instruction, the joint activity, and maintaining accountability. Implications include the following: (1) teacher educators need to tap into the knowledge base that underscores science teachers' learning to teach philosophies when computer technology is used in instruction. (2) Teacher educators need to emphasize the essential idea that learning and cognition is not situated within the computer technology but within the pedagogical practices, specifically the participation structures. (3) The pedagogical practices developed with the integration or with the use of computer technology underscored by the teachers' own knowledge of classroom contexts and curriculum needs to be the focus for how students learn science content with computer technology instead of just focusing on how computer technology solely supports students learning of science content.

  9. Teachers' Organization of Participation Structures for Teaching Science with Computer Technology

    Science.gov (United States)

    Subramaniam, Karthigeyan

    2016-08-01

    This paper describes a qualitative study that investigated the nature of the participation structures and how the participation structures were organized by four science teachers when they constructed and communicated science content in their classrooms with computer technology. Participation structures focus on the activity structures and processes in social settings like classrooms thereby providing glimpses into the complex dynamics of teacher-students interactions, configurations, and conventions during collective meaning making and knowledge creation. Data included observations, interviews, and focus group interviews. Analysis revealed that the dominant participation structure evident within participants' instruction with computer technology was ( Teacher) initiation-( Student and Teacher) response sequences-( Teacher) evaluate participation structure. Three key events characterized the how participants organized this participation structure in their classrooms: setting the stage for interactive instruction, the joint activity, and maintaining accountability. Implications include the following: (1) teacher educators need to tap into the knowledge base that underscores science teachers' learning to teach philosophies when computer technology is used in instruction. (2) Teacher educators need to emphasize the essential idea that learning and cognition is not situated within the computer technology but within the pedagogical practices, specifically the participation structures. (3) The pedagogical practices developed with the integration or with the use of computer technology underscored by the teachers' own knowledge of classroom contexts and curriculum needs to be the focus for how students learn science content with computer technology instead of just focusing on how computer technology solely supports students learning of science content.

  10. Relating chemical structure to the mechanical and electrical properties in organic crystalline semiconductors

    Science.gov (United States)

    Reyes-Martinez, Marcos; Crosby, Alfred; Briseno, Alejandro

    2015-03-01

    The study of the physical properties of organic single crystals (OSCs) has allowed the advent of a new generation of high-performance organic electronic devices. Despite the profound knowledge of the structural and electrical properties of OSCs, there is little research on their mechanical properties and the effects of strain on their electrical properties. This presentation brings new understanding of the intrinsic mechanical properties of organic semiconductors and the effect of deformation in charge transport phenomena. We utilize rubrene single crystals as model systems. Due to the limited dimensions of crystals and the associated handling difficulty, the wrinkling instability is chosen as a metrology tool for the in-plane elastic constants. To elucidate the effects of mechanical strain on charge transport, we take advantage of wrinkling as a unique way to strain the conducting channel of field-effect transistors in a non-destructive, reversible, and predictable manner and demonstrate the mechanical modulation of field-effect mobility. Our contributions are the first to quantitatively correlate the crystal structure and the mechanical properties of OSCs, as well as the first to study their electro-mechanical behavior. They also represent a significant step forward in structure-function relationships in organic semiconductors and lay the foundation for the effective use of organic semiconductors in mechanically demanding applications such as pressure sensors and electronic skins.

  11. Macrozoobenthic community structure in two Portuguese estuaries: Relationship with organic enrichment and nutrient gradients

    Science.gov (United States)

    Mucha, Ana Paula; Costa, Maria Helena

    1999-07-01

    The aim of this work consists in the study of the structural and functional aspects of the macrozoobenthic communities and their relationships with the organic enrichment and nutrient gradients in water and sediment. The study was carried out in two coastal ecosystems under strong anthropogenic pressure: the Sado estuary and the Aveiro Lagoon. Samples were collected at four stations between October 1994 and April 1995. The results obtained allowed us to state that spatial variability, both horizontal and vertical, was higher than the temporal variability. This was due to local hydrodynamism, organic load and granulometric structure of the sediment. Comparing the community structure at the different stations, it was possible to observe the existence of disturbance cases not directly related to organic enrichment gradients. The interpretation of the functional role of the macrozoobenthic communities at the water-sediment interface was based on the trophodynamic group classification. This approach allowed us to state that the sensitivity of different groups to organic enrichment, confirming the role of burrower subsurface-deposit feeders as opportunists associated with organic enrichment and, on the other hand, the influence of certain trophodynamic groups in the nutrient transfer processes, particularly the association between tube-builder omnivores and burrower carnivore and nitrate content in interstitial water.

  12. Fine structure of uterus and non-functioning paruterine organ in Orthoskrjabinia junlanae (Cestoda, Cyclophyllidea).

    Science.gov (United States)

    Korneva, Janetta V; Kornienko, Svetlana A; Jones, Malcolm K

    2016-06-01

    Some cyclophyllidean cestodes provide protection for their eggs in the external environment by providing them with additional protective layers around the egg membranes. In attempting to examine such adaptations, the microanatomy and fine structure of the uterus of pregravid and gravid proglottids of the cyclophyllidean cestode Orthoskrjabinia junlanae, a parasite of mammals that inhabit a terrestrial but moist environment, were studied. In the initial stages of uterine development, developing embryos locate freely in the lumen of a saccate uterus that later partitions into chambers. Each chamber that forms encloses several embryos. The chambers are surrounded by muscle cells that synthesize extracellular matrix actively. The paruterine organs consist of stacks of flattened long outgrowths of muscular cells, interspersed with small lipid droplets. In the gravid proglottids, the size of paruterine organ increases and consists of flattened basal and small rounded apical parts separated by constrictions. The fine structure of the organ wall remains the same: sparse nuclei and stacks of flattened cytoplasmic outgrowths but internal invaginations or lumen in the paruterine organ are absent. Completely developed eggs remain localized in the uterus. Based on the comparative morpho-functional analysis of uterine and paruterine organs and uterine capsules in cestodes, we conclude that these non-functioning paruterine organ in O. junlanae is an example of an atavism. We postulate that the life cycle of the parasite, which infects mammals living in wet habitats, where threats of desiccation of parasite ova is reduced, has favoured a reversion to a more ancestral form of uterine development. PMID:26997340

  13. Material structure-composite morphology-photovoltaic performance relationship for organic bulk heterojunction solar cells.

    Science.gov (United States)

    Troshin, Pavel A; Mukhacheva, Olga A; Goryachev, Andrey E; Dremova, Nadezhda N; Voylov, Dmitry; Ulbricht, Christoph; Egbe, Daniel A M; Sariciftci, Niyazi Serdar; Razumov, Vladimir F

    2012-10-01

    Conjugated PPV-PPE copolymer has been investigated in organic solar cells in combination with twelve different fullerene derivatives. It was shown that the length of solubilizing alkyl chains in the fullerene derivative structures correlates well with the performance of photovoltaic cells.

  14. Preparation of Ferrierite Zeolite Membranes in the Absence of Organic Structure-directing Agents

    Institute of Scientific and Technical Information of China (English)

    Xiao Hui SU; Gang LI; Rui Sen LIN; Eiichi KIKUCHI; Masahiko MATSUKATA

    2006-01-01

    Ferrierite zeolite membranes were prepared for the first time in the absence of organic structure-directing agents (SDA) on the surface of a porous α-alumina support. These membranes were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and pervaporation tests.

  15. Structural organization of surfactant aggregates in vacuo: a molecular dynamics and well-tempered metadynamics study.

    Science.gov (United States)

    Longhi, Giovanna; Fornili, Sandro L; Turco Liveri, Vincenzo

    2015-07-01

    Experimental investigations using mass spectrometry have established that surfactant molecules are able to form aggregates in the gas phase. However, there is no general consensus on the organization of these aggregates and how it depends on the aggregation number and surfactant molecular structure. In the present paper we investigate the structural organization of some surfactants in vacuo by molecular dynamics and well-tempered metadynamics simulations to widely explore the space of their possible conformations in vacuo. To study how the specific molecular features of such compounds affect their organization, we have considered as paradigmatic surfactants, the anionic single-chain sodium dodecyl sulfate (SDS), the anionic double-chain sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and the zwitterionic single-chain dodecyl phosphatidyl choline (DPC) within a wide aggregation number range (from 5 to 100). We observe that for low aggregation numbers the aggregates show in vacuo the typical structure of reverse micelles, while for large aggregation numbers a variety of globular aggregates occur that are characterized by the coexistence of interlaced domains formed by the polar or ionic heads and by the alkyl chains of the surfactants. Well-tempered metadynamics simulations allows us to confirm that the structural organizations obtained after 50 ns of molecular dynamics simulations are practically the equilibrium ones. Similarities and differences of surfactant aggregates in vacuo and in apolar media are also discussed. PMID:26050747

  16. Electronic structure of the quasi-one-dimensional organic conductor TTF-TCNQ

    DEFF Research Database (Denmark)

    Sing, M.; Schwingenschlögl, U.; Claessen, R.;

    2003-01-01

    We study the electronic structure of the quasi-one-dimensional organic conductor TTF-TCNQ by means of density-functional band theory, Hubbard model calculations, and angle-resolved photoelectron spectroscopy (ARPES). The experimental spectra reveal significant quantitative and qualitative...

  17. Structure of phase-separated ferroelectric/ semiconducting polymer blends for organic non-volatile memories

    NARCIS (Netherlands)

    Mcneill, C.R.; Asadi, K.; Watts, B.; Blom, P.W.M.; Leeuw, D.M. de

    2010-01-01

    The phase-separated structure of blends of the ferroelectric polymer P(VDF-TrFE) and the semiconducting polymer P3HT used in organic non-volatile memories is revealed with soft X-ray spectromicroscopy. These thin-film blends show a columnar morphology, with P3HT-rich columns enclosed in a continuous

  18. A Conceptual Framework of Corporate and Business Ethics across Organizations: Structures, Processes and Performance

    Science.gov (United States)

    Svensson, Goran; Wood, Greg

    2011-01-01

    Purpose: The objective of this paper is to introduce and describe a conceptual framework of corporate and business ethics across organizations in terms of ethical structures, ethical processes and ethical performance. Design/methodology/approach: A framework is outlined and positioned incorporating an ethical frame of reference in the field of…

  19. Ethnically Diverse Students' Knowledge Structures in First-Semester Organic Chemistry

    Science.gov (United States)

    Lopez, Enrique J.; Shavelson, Richard J.; Nandagopal, Kiruthiga; Szu, Evan; Penn, John

    2014-01-01

    Chemistry courses remain a challenge for many undergraduate students. In particular, first-semester organic chemistry has been labeled as a gatekeeper with high attrition rates, especially among students of color. Our study examines a key factor related to conceptual understanding in science and predictive of course outcomes-knowledge structures.…

  20. Modeling structure and flexibility of Candida antarctica lipase B in organic solvents

    Directory of Open Access Journals (Sweden)

    Pleiss Jürgen

    2008-02-01

    Full Text Available Abstract Background The structure and flexibility of Candida antarctica lipase B in water and five different organic solvent models was investigated using multiple molecular dynamics simulations to describe the effect of solvents on structure and dynamics. Interactions of the solvents with the protein and the distribution of water molecules at the protein surface were examined. Results The simulated structure was independent of the solvent, and had a low deviation from the crystal structure. However, the hydrophilic surface of CALB in non-polar solvents decreased by 10% in comparison to water, while the hydrophobic surface is slightly increased by 1%. There is a large influence on the flexibility depending on the dielectric constant of the solvent, with a high flexibility in water and a low flexibility in organic solvents. With decreasing dielectric constant, the number of surface bound water molecules significantly increased and a spanning water network with an increasing size was formed. Conclusion The reduced flexibility of Candida antarctica lipase B in organic solvents is caused by a spanning water network resulting from less mobile and slowly exchanging water molecules at the protein-surface. The reduced flexibility of Candida antarctica lipase B in organic solvent is not only caused by the interactions between solvent-protein, but mainly by the formation of a spanning water network.

  1. Hybrid organic-inorganic structured materials as single-site heterogeneous catalysts

    OpenAIRE

    Díaz Morales, Urbano Manuel; Boronat Zaragoza, Mercedes; Corma Canós, Avelino

    2012-01-01

    Catalyst selectivity is associated with well-defined homogeneous active sites. Transition metal complexes and organocatalysts are highly active and selective in the homogeneous phase, and their heterogenization by incorporating them into inorganic solid materials allows combining their excellent catalytic activity with improved separation, recovering and recycling properties. In this article, we present the structural characteristics and catalytic properties of hybrid organic inorganic materi...

  2. Anthraquinone with tailored structure for a nonaqueous metal-organic redox flow battery.

    Science.gov (United States)

    Wang, Wei; Xu, Wu; Cosimbescu, Lelia; Choi, Daiwon; Li, Liyu; Yang, Zhenguo

    2012-07-01

    A nonaqueous, hybrid metal-organic redox flow battery based on tailored anthraquinone structure is demonstrated to have an energy efficiency of ~82% and a specific discharge energy density similar to those of aqueous redox flow batteries, which is due to the significantly improved solubility of anthraquinone in supporting electrolytes. PMID:22641051

  3. Metal-Organic Frameworks with d-f Cyanide Bridges: Structural Diversity, Bonding Regime, and Magnetism

    NARCIS (Netherlands)

    M. Ferbinteanu; F. Cimpoesu; S. Tanase

    2015-01-01

    We present a selection of metal-organic frameworks based on d-f and f-f linkages, discussing their structural features and properties from experimental and theoretical viewpoints. We give an overview of our own synthetic and modeling methodologies, highlighting the complexity of the interdisciplinar

  4. Method for analyzing structural changes of flexible metal-organic frameworks induced by adsorbates

    NARCIS (Netherlands)

    D. Dubbeldam; R. Krishna; R.Q. Snurr

    2009-01-01

    Metal−organic frameworks (MOFs) have crystal structures that exhibit unusual flexibility. An extreme example is that of the "breathing MOF" MIL-53 that expands or shrinks to admit guest molecules like CO2 and water. We present a powerful simulation tool to quickly calculate unit cell shape and size

  5. High-Efficiency White Organic Light-Emitting Devices Based on Multiple Quantum-Well Structure

    Institute of Scientific and Technical Information of China (English)

    DUAN Yu; HOU Jing-Ying; WU Zhi-Jun; CHENG Gang; ZHAO Yi; LIU Shi-Yong

    2004-01-01

    @@ We report the white organic-light devices (WOLEDs) employing a multiple quantum-well (MQW) structure,which consist of alternate layers of 4,48-bis(2,28-diphenylvinyl)-1,18-biphenyl (DPVBi) and (DPVBi:Rubrene) as the potential barrier and the potential well, respectively. The results demonstrate that the MQW structure can prominently increase the performance of WOLEDs, the double quantum well device exhibits the efficiency up to 5.4 cd/A, and yields a peak luminance of 14206 cd/m2. It is also interesting to find that the MQW structure can enhance the colour stability of WOLEDs at different voltages.

  6. Molecular design chemical structure generation from the properties of pure organic compounds

    CERN Document Server

    Horvath, AL

    1992-01-01

    This book is a systematic presentation of the methods that have been developed for the interpretation of molecular modeling to the design of new chemicals. The main feature of the compilation is the co-ordination of the various scientific disciplines required for the generation of new compounds. The five chapters deal with such areas as structure and properties of organic compounds, relationships between structure and properties, and models for structure generation. The subject is covered in sufficient depth to provide readers with the necessary background to understand the modeling

  7. TERRITORIAL STRUCTURES AND THE POTENTIAL OF ROMANIA’S ORGANIC AGRICULTURAL HOLDINGS

    Directory of Open Access Journals (Sweden)

    Iulian ALECU

    2015-04-01

    Full Text Available The paper seeks to highlight the main issues that the implementation of organic agriculture in Romania has to face, at territorial and national level in regard to the situation of the vegetal and animal sector. The comparison of the percentages showed, on the one hand, a considerable organic potential at national level, and on the other hand, the necessity to embrace a different structure by means of organizational measures. The level of the used markers highlighted an increasing trend of organic agriculture, by means of the increase of the total area and of the areas in conversion. This can be achieved by increasing the average surface per holding and intensifying the average number of animals per organic agricultural holding, situations which at present, at national level, are associated with very noticeable variation forms.

  8. Long Range Modification of a Metal Surface Electronic Structure by an Organic Semiconductor

    Science.gov (United States)

    Wang, Jingying; Dougherty, Daniel

    2015-03-01

    In an organic spintronic device the interaction between electrode surface and organic semiconductor layer plays an important role in spin injection at this interface. The antiferromagnetic material Cr(001) is known to have a spin-polarized state near Fermi level that could potentially hybridize with organic molecules. Here we report our STM/STS study of electronic structure at interface between an organic semiconductor, PTCDA, and Cr(001) surface. The study shows that the surface state at Fermi level of Cr(001) can be broadened by PTCDA molecules deposited on the surface due to hybridization of PTCDA molecular orbital and conduction sp band of Cr(001). This indirect modification is not only localized at molecular adsorption sites, but also extends several nm to bare surrounding Cr(001) surface and decays with distance away from PTCDA molecules.

  9. Estimation of Formation Enthalpies of Organic Pollutants from a New Structural Group Contribution Method

    Institute of Scientific and Technical Information of China (English)

    Mehdi Bagheri; Afshin Bakhtiari; Masoume Jaberi

    2013-01-01

    Chemical stability and reactivity of organic pollutants is dependent to their formation enthalpies.The main objective of this study is to provide simple straightforward strategy for prediction of the formation enthalpies of wide range organic pollutants only from their structural functional groups.Using such an extended dataset comprising 1694 organic chemicals from 77 diverse material classes benefits the generalizability and reliability of the study.The new suggested collection of 12 functional groups and a simple linear regression lead to promising statistics of R2=0.958,Q2Loo =0.956,and δAEE=57 kJ·mol-1 for the whole dataset.Moreover,unknown experimental formation enthalpies for 27 organic pollutants are estimated by the presented approach.The resultant model needs no technical software/calculations,and thus can be easily applied by a non-specialist user.

  10. Performance Evaluation of Rural Cooperative Economic Organizations in Hunan Province Based on Structural Equation

    Institute of Scientific and Technical Information of China (English)

    Naman; YANG

    2015-01-01

    Using the method of structural equation and balanced scorecard,this paper establishes the evaluation indicators and evaluation model for the performance of 21 rural cooperative economic organizations in X City of Hunan Province,and analyzes the relationship between indicators and dimensions of performance evaluation indicators,in order to find the influencing factors,obstacles and successful experience concerning the development of rural cooperative economic organizations. According to model analysis and conclusions,this paper sets forth the recommendations for promoting the development of rural cooperative economic organizations in Hunan Province,in order to provide a scientific basis for the institutional design and mechanism innovation of rural cooperative economic organizations in Hunan Province.

  11. When hole extraction determines charge transfer across metal-organic-metal structure

    Science.gov (United States)

    Govor, L. V.; Reiter, G.; Parisi, J.

    2016-03-01

    We examined the charge transfer in metal-organic-metal structure, where the contact resistance of the extracting interface is larger than the resistance of the organic crystalline material and the resistance of the injecting interface. If direct tunneling (low voltage) and Fowler-Nordheim tunnelling (high voltage) across both interfaces take place, part of the injected holes remains located in the organic crystal because of the blocking action of the extracting interface, but not because of traps within the organic crystalline material (which was negligible). If Fowler-Nordheim tunneling across the injecting interface and direct tunneling across the extracting interface take place for high voltages, the latter leads to the deviation of the total current-voltage characteristic from the power law I∼ Vγ with γ>2 to Ohm's law with γ≃1.0 .

  12. "Structuration" by Intellectual Organization: The Configuration of Knowledge in Relations among Structural Components in Networks of Science

    CERN Document Server

    Leydesdorff, Loet

    2010-01-01

    Using aggregated journal-journal citation networks, the measurement of the knowledge base in empirical systems is factor-analyzed in two cases of interdisciplinary developments during the period 1995-2005: (i) the development of nanotechnology in the natural sciences and (ii) the development of communication studies as an interdiscipline between social psychology and political science. The results are compared with a case of stable development: the citation networks of core journals in chemistry. These citation networks are intellectually organized by networks of expectations in the knowledge base at the specialty (that is, above-journal) level. This "structuration" of structural components (over time) can be measured as configurational information. The latter is compared with the Shannon-type information generated in the interactions among structural components: the difference between these two measures provides us with a measure for the redundancy generated by the specification of a model in the knowledge b...

  13. Covalent organic frameworks: a materials platform for structural and functional designs

    Science.gov (United States)

    Huang, Ning; Wang, Ping; Jiang, Donglin

    2016-10-01

    Covalent organic frameworks (COFs) are a class of crystalline porous polymer that allows the atomically precise integration of organic units into extended structures with periodic skeletons and ordered nanopores. One important feature of COFs is that they are designable; that is, the geometry and dimensions of the building blocks can be controlled to direct the topological evolution of structural periodicity. The diversity of building blocks and covalent linkage topology schemes make COFs an emerging materials platform for structural control and functional design. Indeed, COF architectures offer confined molecular spaces for the interplay of photons, excitons, electrons, holes, ions and guest molecules, thereby exhibiting unique properties and functions. In this Review, we summarize the major progress in the field of COFs and recent achievements in developing new design principles and synthetic strategies. We highlight cutting-edge functional designs and identify fundamental issues that need to be addressed in conjunction with future research directions from chemistry, physics and materials perspectives.

  14. Laser Control of Self-Organization Process in Microscopic Region and Fabrication of Fine Microporous Structure

    Directory of Open Access Journals (Sweden)

    Yukimasa Matsumura

    2012-01-01

    Full Text Available We present a controlling technique of microporous structure by laser irradiation during self-organization process. Self-organization process is fabrication method of microstructure. Polymer solution was dropped on the substrate at high humid condition. Water in air appears dropping air temperature below the dew point. The honeycomb structure with regularly aligned pores on the film was fabricated by attaching water droplets onto the solution surface. We demonstrate that it was possible to prevent forming pores at the region of laser irradiation and flat surface was fabricated. We also demonstrated that a combination structure with two pore sizes and flat surface was produced by a single laser-pulse irradiation. Our method is a unique microfabrication processing technique that combines the advantages of bottom-up and top-down techniques. This method is a promising technique that can be applied to produce for photonic crystals, biological cell culturing, surface science and electronics fields, and so forth.

  15. Assessment of personality organization in couple relationships: factorial structure of the inventory of personality organization and incremental validity over neuroticism.

    Science.gov (United States)

    Verreault, Melissa; Sabourin, Stéphane; Lussier, Yvan; Normandin, Lina; Clarkin, John F

    2013-01-01

    Drawing on a sample of 372 French-Canadian couples, this study examined the factorial structure of a 20-item abbreviated version of the Inventory of Personality Organization (IPO) across a sample of couples and tested if identity diffusion, primitive defenses, and reality testing explain additional variance in couple distress when controlling for neuroticism. The IPO is based on Kernberg's conceptualization of personality organization (Kernberg, 1976 ). Gender differences were also studied through an examination of the value of both self-reported and partner-reported personality in the prediction of each partner's couple satisfaction. Results of confirmatory factor analyses indicated that the tripartite model of the short version of the IPO provided an acceptable fit and proved invariant when tested on couples. Actor-Partner Interdependence Model analyses (Kenny, Kashy, & Cook, 2006 ) showed that elevated neuroticism predicted higher endorsement of primitive defenses, which in turn predict couple dissatisfaction. There was also a direct, negative path from neuroticism to dyadic adjustment. Finally, self-reported neuroticism scores predicted high utilization of primitive defenses by the partner, and low partner-reported couple satisfaction. Furthermore, high self-reported utilization of primitive defenses predicted low couple satisfaction. PMID:22906020

  16. The Changing Needs for Higher Education Organizations Structure in Vietnam: Evidence from Japanese, Taiwanese, and Thai Universities

    Directory of Open Access Journals (Sweden)

    Minh-Quang Duong

    2013-02-01

    Full Text Available Organizational change is the process of changing the structure of the organization and the attitudes of members in the organization. During the last decade, both Vietnamese social and educational organizations have slowly changed in their organizational structure as a barrier to the development in the era of globalization and internationalization in Vietnam. This paper is an attempt to discuss the factors which affect Vietnamese higher educational organization. Discussions on the viewpoint of higher educational organization structure of Japan, Taiwan, and Thailand. Furthermore, this paper will contribute to improve educational management, and serve as a useful reference for future higher education’s school mergers.

  17. Ordered structures based on self-organized Au and CdSe nanoparticles

    International Nuclear Information System (INIS)

    Methods for obtaining cadmium selenide and gold nanoparticles have been developed. The sizes of the nanoparticles are determined and the morphology, structure, and chemical composition of these nanoparticles and their ensembles are studied by a complex of structural methods: electron diffraction, X-ray diffraction, energy-dispersive X-ray analysis, high-resolution transmission electron microscopy, and small-angle X-ray scattering. Gold nanoparticles are mainly spherical and have an average size of 10 nm. They are single-phase and have an fcc crystal structure. Samples of synthesized CdSe nanoparticles contain monodisperse spherical particles 12 nm in size with a wurtzite structure. The deposition of nanoparticles on a carbon substrate is accompanied by their self-organization into a closely packed two-dimensional structure with a pronounced texture in which all nanoparticles are oriented in the [001] direction perpendicularly to the carbon substrate plane.

  18. Metal–organic coordinated multilayer film formation: Quantitative analysis of composition and structure

    Energy Technology Data Exchange (ETDEWEB)

    Benson, Alexandra S.; Elinski, Meagan B.; Ohnsorg, Monica L.; Beaudoin, Christopher K.; Alexander, Kyle A.; Peaslee, Graham F.; DeYoung, Paul A.; Anderson, Mary E., E-mail: meanderson@hope.edu

    2015-09-01

    Metal–organic coordinated multilayers are self-assembled thin films fabricated by alternating solution–phase deposition of bifunctional organic molecules and metal ions. The multilayer film composed of α,ω-mercaptoalkanoic acid and Cu (II) has been the focus of fundamental and applied research with its robust reproducibility and seemingly simple hierarchical architecture. However, internal structure and composition have not been unambiguously established. The composition of films up to thirty layers thick was investigated using Rutherford backscattering spectrometry and particle induced X-ray emission. Findings show these films are copper enriched, elucidating a 2:1 ratio for the ion to molecule complexation at the metal–organic interface. Results also reveal that these films have an average layer density similar to literature values established for a self-assembled monolayer, indicating a robust and stable structure. The surface structures of multilayer films have been characterized by contact angle goniometry, ellipsometry, and scanning probe microscopy. A morphological transition is observed as film thickness increases from the first few foundational layers to films containing five or more layers. Surface roughness analysis quantifies this evolution as the film initially increases in roughness before obtaining a lower roughness comparable to the underlying gold substrate. Quantitative analysis of topographical structure and internal composition for metal–organic coordinated multilayers as a function of number of deposited layers has implications for their incorporation in the fields of photonics and nanolithography. - Highlights: • Layer-by-layer deposition is examined by scanning probe microscopy and ion beam analysis. • Film growth undergoes morphological evolution during foundational layer deposition. • Image analysis quantified surface features such as roughness, grain size, and coverage. • Molecular density of each film layer is found to

  19. Self-assembly of metal-organic coordination structures on surfaces

    Science.gov (United States)

    Dong, Lei; Gao, Zi'Ang; Lin, Nian

    2016-08-01

    Metal-organic coordination structures are materials comprising reticular metal centers and organic linkers in which the two constituents bind with each other via metal-ligand coordination interaction. The underlying chemistry is more than a century old but has attracted tremendous attention in the last two decades owing to the rapidly development of metal-organic (or porous coordination) frameworks. These metal-coordination materials exhibit extraordinarily versatile topologies and many potential applications. Since 2002, this traditionally three-dimensional chemistry has been extended to two-dimensional space, that is, to synthesize metal-organic coordination structures directly on solid surfaces. This endeavor has made possible a wide range of so-called surface-confined metal-organic networks (SMONs) whose topology, composition, property and function can be tailored by applying the principle of rational design. The coordination chemistry manifests unique characteristics at the surfaces, and in turn the surfaces provide additional control for design structures and properties that are inaccessible in three-dimensional space. In this review, our goal is to comprehensively cover the progress made in the last 15 years in this rapidly developing field. The review summarizes (1) the experimental and theoretical techniques used in this field including scanning tunneling microscopy and spectroscopy, low-energy electron diffraction, X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, density functional theory, and Monte Carlo and kinetic Monte Carlo simulation; (2) molecular ligands, metal atoms, substrates, and coordination motifs utilized for synthesizing SMON; (3) representative SMON structures with different topologies ranging from finite-size discrete clusters to one-dimensional chains, two-dimensional periodical frameworks and random networks; and (4) the properties and potential applications of SMONs. We conclude the review with some perspectives.

  20. Structural and functional rich club organization of the brain in children and adults.

    Directory of Open Access Journals (Sweden)

    David S Grayson

    Full Text Available Recent studies using Magnetic Resonance Imaging (MRI have proposed that the brain's white matter is organized as a rich club, whereby the most highly connected regions of the brain are also highly connected to each other. Here we use both functional and diffusion-weighted MRI in the human brain to investigate whether the rich club phenomena is present with functional connectivity, and how this organization relates to the structural phenomena. We also examine whether rich club regions serve to integrate information between distinct brain systems, and conclude with a brief investigation of the developmental trajectory of rich-club phenomena. In agreement with prior work, both adults and children showed robust structural rich club organization, comprising regions of the superior medial frontal/dACC, medial parietal/PCC, insula, and inferior temporal cortex. We also show that these regions were highly integrated across the brain's major networks. Functional brain networks were found to have rich club phenomena in a similar spatial layout, but a high level of segregation between systems. While no significant differences between adults and children were found structurally, adults showed significantly greater functional rich club organization. This difference appeared to be driven by a specific set of connections between superior parietal, insula, and supramarginal cortex. In sum, this work highlights the existence of both a structural and functional rich club in adult and child populations with some functional changes over development. It also offers a potential target in examining atypical network organization in common developmental brain disorders, such as ADHD and Autism.

  1. The interplay between habitat structure and chemical contaminants on biotic responses of benthic organisms.

    Science.gov (United States)

    Mayer-Pinto, Mariana; Matias, Miguel G; Coleman, Ross A

    2016-01-01

    Habitat structure influences the diversity and distribution of organisms, potentially affecting their response to disturbances by either affecting their 'susceptibility' or through the provision of resources that can mitigate impacts of disturbances. Chemical disturbances due to contamination are associated with decreases in diversity and functioning of systems and are also likely to increase due to coastal urbanisation. Understanding how habitat structure interacts with contaminants is essential to predict and therefore manage such effects, minimising their consequences to marine systems. Here, we manipulated two structurally different habitats and exposed them to different types of contaminants. The effects of contamination and habitat structure interacted, affecting species richness. More complex experimental habitats were colonized by a greater diversity of organisms than the less complex habitats. These differences disappeared, however, when habitats were exposed to contaminants, suggesting that contaminants can override effects of habitats structure at small spatial scales. These results provide insight into the complex ways that habitat structure and contamination interact and the need to incorporate evidence of biotic responses from individual disturbances to multiple stressors. Such effects need to be taken into account when designing and planning management and conservation strategies to natural systems. PMID:27168991

  2. Structure of sperm, spermatozeugmata and 'lateral organs' in the bivalve Arthritica (Galeommatoidea: Leptonidae)

    DEFF Research Database (Denmark)

    Jespersen, Åse; Lützen, Jørgen

    2009-01-01

    The position and structure of paired 'lateral organs' in the foot of Arthritica semen and Arthritica bifurca might indicate a chemosensory function. In both species part of the organ is also glandular. In A. semen the glandular epithelium is detached piecemeal and, probably by means of the foot......, is moved to and grafted upon the gills of the same individual. The transferred epithelia appear as disk-shaped actively secretory 'gill bodies' which, attached to the abfrontal side of the inner demibranch, replace the ordinary unciliated gill epithelium. The secretion is liberated into the suprabranchial...

  3. Estimation of carrier mobility at organic semiconductor/insulator interface using an asymmetric capacitive test structure

    Directory of Open Access Journals (Sweden)

    Rajesh Agarwal

    2016-04-01

    Full Text Available Mobility of carriers at the organic/insulator interface is crucial to the performance of organic thin film transistors. The present work describes estimation of mobility using admittance measurements performed on an asymmetric capacitive test structure. Besides the advantage of simplicity, it is shown that at low frequencies, the measured capacitance comes from a large area of channel making the capacitance-voltage characteristics insensitive to contact resistances. 2-D numerical simulation and experimental results obtained with Pentacene/Poly(4-vinyphenol system are presented to illustrate the operation and advantages of the proposed technique.

  4. Impact of organic and inorganic nanomaterials in the soil microbial community structure

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Veronica; Lopes, Isabel [Department of Biology, University of Aveiro, Campus Universitario de Santiago, P-3810-193 Aveiro (Portugal); CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Campus de Santiago 3810-193 Aveiro (Portugal); Rocha-Santos, Teresa [ISEIT/Viseu, Instituto Piaget, Estrada do Alto do Gaio, Galifonge, 3515-776 Lordosa, Viseu (Portugal); Santos, Ana L. [Department of Biology, University of Aveiro, Campus Universitario de Santiago, P-3810-193 Aveiro (Portugal); CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Campus de Santiago 3810-193 Aveiro (Portugal); Rasteiro, Graca M.; Antunes, Filipe [CIEPQPF, Department of Chemical Engineering, Faculty of Science and Technology, Polo II, University of Coimbra, 3030-290 Coimbra (Portugal); Goncalves, Fernando; Soares, Amadeu M.V.M.; Cunha, Angela; Almeida, Adelaide [Department of Biology, University of Aveiro, Campus Universitario de Santiago, P-3810-193 Aveiro (Portugal); CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Campus de Santiago 3810-193 Aveiro (Portugal); Gomes, Newton N.C.M., E-mail: gomesncm@ua.pt [Department of Biology, University of Aveiro, Campus Universitario de Santiago, P-3810-193 Aveiro (Portugal); CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Campus de Santiago 3810-193 Aveiro (Portugal); Pereira, Ruth [Department of Biology, Faculty of Science, University of Porto, Rua do Campo Alegre 4169-007 Porto (Portugal); CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Campus de Santiago 3810-193 Aveiro (Portugal)

    2012-05-01

    In this study the effect of organic and inorganic nanomaterials (NMs) on the structural diversity of the soil microbial community was investigated by Denaturing Gradient Gel Electrophoresis, after amplification with universal primers for the bacterial region V6-V8 of 16S rDNA. The polymers of carboxylmethyl-cellulose (CMC), of hydrophobically modified CMC (HM-CMC), and hydrophobically modified polyethylglycol (HM-PEG); the vesicles of sodium dodecyl sulphate/didodecyl dimethylammonium bromide (SDS/DDAB) and of monoolein/sodium oleate (Mo/NaO); titanium oxide (TiO{sub 2}), titanium silicon oxide (TiSiO{sub 4}), CdSe/ZnS quantum dots, gold nanorods, and Fe/Co magnetic fluid were the NMs tested. Soil samples were incubated, for a period of 30 days, after being spiked with NM suspensions previously characterized by Dynamic Light Scattering (DLS) or by an ultrahigh-resolution scanning electron microscope (SEM). The analysis of similarities (ANOSIM) of DGGE profiles showed that gold nanorods, TiO{sub 2}, CMC, HM-CMC, HM-PEG, and SDS/DDAB have significantly affected the structural diversity of the soil bacterial community. - Highlights: Black-Right-Pointing-Pointer Organic and inorganic nanomaterials on soil microbial community. Black-Right-Pointing-Pointer Structural diversity was investigated by Denaturing Gradient Gel Electrophoresis. Black-Right-Pointing-Pointer All the organic nanomaterials, TiO{sub 2} and gold nanorods significantly affected the structural diversity.

  5. Organizations

    DEFF Research Database (Denmark)

    Hatch, Mary Jo

    Most of us recognize that organizations are everywhere. You meet them on every street corner in the form of families and shops, study in them, work for them, buy from them, pay taxes to them. But have you given much thought to where they came from, what they are today, and what they might become...... and considers many more. Mary Jo Hatch introduces the concept of organizations by presenting definitions and ideas drawn from the a variety of subject areas including the physical sciences, economics, sociology, psychology, anthropology, literature, and the visual and performing arts. Drawing on examples from...... prehistory and everyday life, from the animal kingdom as well as from business, government, and other formal organizations, Hatch provides a lively and thought provoking introduction to the process of organization....

  6. Structural elucidation of active layers in organic electronic devices via NEXAFS

    Energy Technology Data Exchange (ETDEWEB)

    Loo, Y-L, E-mail: lloo@princeton.edu [Chemical and Biological Engineering Department, Princeton University, Princeton NJ 08544-5263 (United States)

    2010-11-15

    The electrically-active thin films within organic electronic devices are structurally complex; the details of which depend strongly on both inherent materials properties as well as processing history. Given structural heterogeneities within such electrically-active thin films can influence device characteristics dramatically, understanding - and ultimately, controlling - structural development is a necessary precursor to producing reliable and high-performance electronic devices. Highlighted herein are several examples from our laboratories in which synchrotron soft x-rays based near-edge x-ray absorption fine structure spectroscopy is used to elucidate (i) ensemble-average molecular orientation (ii) relative surface coverage and (iii) vertical compositional profile in such electrically-active thin films.

  7. Hierarchical pictorial structures for simultaneously localizing multiple organs in volumetric pre-scan CT

    Science.gov (United States)

    Montillo, Albert; Song, Qi; Das, Bipul; Yin, Zhye

    2015-03-01

    Parsing volumetric computed tomography (CT) into 10 or more salient organs simultaneously is a challenging task with many applications such as personalized scan planning and dose reporting. In the clinic, pre-scan data can come in the form of very low dose volumes acquired just prior to the primary scan or from an existing primary scan. To localize organs in such diverse data, we propose a new learning based framework that we call hierarchical pictorial structures (HPS) which builds multiple levels of models in a tree-like hierarchy that mirrors the natural decomposition of human anatomy from gross structures to finer structures. Each node of our hierarchical model learns (1) the local appearance and shape of structures, and (2) a generative global model that learns probabilistic, structural arrangement. Our main contribution is twofold. First we embed the pictorial structures approach in a hierarchical framework which reduces test time image interpretation and allows for the incorporation of additional geometric constraints that robustly guide model fitting in the presence of noise. Second we guide our HPS framework with the probabilistic cost maps extracted using random decision forests using volumetric 3D HOG features which makes our model fast to train and fast to apply to novel test data and posses a high degree of invariance to shape distortion and imaging artifacts. All steps require approximate 3 mins to compute and all organs are located with suitably high accuracy for our clinical applications such as personalized scan planning for radiation dose reduction. We assess our method using a database of volumetric CT scans from 81 subjects with widely varying age and pathology and with simulated ultra-low dose cadaver pre-scan data.

  8. Proton Conduction in Sulfonated Organic-Inorganic Hybrid Monoliths with Hierarchical Pore Structure.

    Science.gov (United States)

    von der Lehr, Martin; Seidler, Christopher F; Taffa, Dereje H; Wark, Michael; Smarsly, Bernd M; Marschall, Roland

    2016-09-28

    Porous organic-inorganic hybrid monoliths with hierarchical porosity exhibiting macro- and mesopores are prepared via sol-gel process under variation of the mesopore size. Organic moieties in the pore walls are incorporated by substituting up to 10% of the silicon precursor tetramethylorthosilicate with bisilylated benzene molecules. After functionalization with sulfonic acid groups, the resulting sulfonated hybrid monoliths featuring a bimodal pore structure are investigated regarding proton conduction depending on temperature and relative humidity. The hierarchical pore system and controlled mesopore design turn out to be crucial for sulfonation and proton conduction. These sulfonated hybrid hierarchical monoliths containing only 10% organic precursor exhibit higher proton conduction at different relative humidities than sulfonated periodic mesoporous organosilica made of 100% bisilylated precursors exhibiting solely mesopores, even with a lower concentration of sulfonic acid groups.

  9. Effects of organic enrichment on macrofauna community structure: an experimental approach

    Directory of Open Access Journals (Sweden)

    Rodrigo Riera

    2013-12-01

    Full Text Available The determination of the resilience of benthic assemblages is a capital issue for the off-shore aquaculture industry in its attempts to minimize environmental disturbances. Experimental studies are an important tool for the establishment of thresholds for macrofaunal assemblages inhabiting sandy seabeds. An experiment was conducted with three treatments (Control, 1x and 3x,in which organic load (fish pellets was added (1x (10 g of fish pellets and 3x (30 g. A reduction in abundance of individuals and species richness was found as between the control and organic-enriched treatments. Significant changes in assemblage structure were also found, mainly due to the decrease of the sensitive tanaid Apseudes talpa in organically-enriched treatments. AMBI and M-AMBI indices were calculated and a decrease of ecological status was observed in treatment 3x.

  10. Evolution of Organic Agriculture within Theoretical Frameworks of Structural Change and Transformation

    DEFF Research Database (Denmark)

    Rasmussen, Ole Horn

    it is possibly to draw a link to our initially discussion about definition of organic agriculture. The principles between conventional and organic agriculture differ. We have two kinds of rationalities. Exactly such approach is the methodological hard core in the works of Chayanov and we link to a tentative...... of agricultural structural change. We have three different but intertwined treadmills: a product-, land market- and credit treadmill. Our conclusion is that the greatest reason for the first two treadmills is the scarcity of land. The rule of scarcity is a fundamental rule and must be part of any agricultural...... agriculture. The two competing systems of technology operate with different principles. While in principle organic agriculture internalise conventional agriculture seeks to externalise cost into price. Besides, the external economy of conventional agriculture may be larger and create larger economic synergy...

  11. Buildup of multilayer structures of organic-inorganic hybrid ultra thin films by wet process

    International Nuclear Information System (INIS)

    Multilayer structures of alternate organic and inorganic semiconductors were fabricated by the wet processes that control thickness of each layer with nanometre level. Organic layers were deposited as electron-donor including poly(p-phenylene vinylene) by the layer-by-layer adsorption method. Inorganic layers composed of titanium oxide were fabricated as electron-acceptor by the surface sol-gel process. Clearly, periodic and uniform nanostructures were confirmed by glow discharge optical emission spectroscopy and transmission electron microscopy analyses. The multilayer exhibited a photovoltaic effect under illumination. The fabrication of those structures by wet process under room temperature and normal pressure will be one of the important methods in energy-saving nano-technology

  12. Fine structures of organic photovoltaic thin films probed by frequency-shift electrostatic force microscopy

    Science.gov (United States)

    Araki, Kento; Ie, Yutaka; Aso, Yoshio; Matsumoto, Takuya

    2016-07-01

    The localized charge and electrostatic properties of organic photovoltaic thin films are predominating factors for controlling energy conversion efficiency. The surface potential and electrostatic structures of organic photovoltaic thin films were investigated by frequency shift mode Kelvin force microscopy (KFM) and electrostatic force microscopy (EFM). The KFM images of a poly[2-methoxy-5-(3‧,7‧-dimethyloctyloxy)-1,4-phenylene vinylene]/phenyl-C61-butyric-acid-methyl ester (PCBM) blend thin film reveals that the PCBM domains precipitate as the topmost layer on the thin films. We find fine structures that were not observed in the topography and KFM images. The bias dependence of the EFM images suggests that the EFM contrast reflects the field-induced polarization, indicating the presence of charge trapping sites.

  13. Ion beam assisted deposition of organic molecules: a physical way to realize OLED structures

    Science.gov (United States)

    Moliton, André; Antony, Rémi; Troadec, David; Ratier, Bernard

    2000-05-01

    We demonstrate how the quantum efficiency of an organic light-emitting diode can be improved by a physical way based on the ion beam assisted deposition: the recombination current can be increased by an enhancement of the minority carrier injection while the total current can be decreased by generation of electron traps which reduced the majority current. The quantum efficiency of fluorescence can be also improved by a layer densification with a limitation of the nonradiative centers. As a result, the quantum efficiency of the structure ITO/Helium assisted Alq3/unassisted Alq3/Ca/Al is improved (by around a factor 10) in relation with a virgin structure.

  14. Report on the sixth blind test of organic crystal structure prediction methods

    OpenAIRE

    Cooper, R; others

    2016-01-01

    The sixth blind test of organic crystal structure prediction (CSP) methods has been held, with five target systems: a small nearly rigid molecule, a polymorphic former drug candidate, a chloride salt hydrate, a co-crystal and a bulky flexible molecule. This blind test has seen substantial growth in the number of participants, with the broad range of prediction methods giving a unique insight into the state of the art in the field. Significant progress has been seen in treating flexible molecu...

  15. Structure, organization and dynamics of a Sardinian sand dune plant community

    OpenAIRE

    Cusseddu, Valentina

    2016-01-01

    Coastal sand dunes have attracted the attention of plant ecologists for over a century, but have largely relied on correlations to explain striking dune plant community organization. We experimentally examined longstanding hypotheses that sand binding, interspecific interactions, abiotic factors and seedling recruitment are drivers of sand dune plant community structure in Sardinia, Italy. Removing foundation species from the fore, middle and back dune over 3 years led to erosion and habitat ...

  16. Polyacrylonitrile-derived polyconjugated ladder structures for high performance all-organic dielectric materials.

    Science.gov (United States)

    Liao, Xiaojian; Ding, Yichun; Chen, Linlin; Ye, Wan; Zhu, Jian; Fang, Hong; Hou, Haoqing

    2015-06-25

    A novel all-organic polyconjugated ladder structures-polyimide (PcLS-PI) composite was successfully synthesized, in which PcLS were derived from polyacrylonitrile (PAN). The PcLS-PI composite not only presents high dielectric performances of high dielectric permittivity, low dielectric loss, high electrical breakdown strength and high energy density, but also has excellent mechanical and thermal properties. PMID:26006760

  17. Novel Threadlike Structures May Be Present on the Large Animal Organ Surface: Evidence in Swine Model

    OpenAIRE

    Kyoung-Hee Bae; Sang Hyun Park; Byung-Cheon Lee; Min-Ho Nam; Ji Woong Yoon; Hee-Min Kwon; Seung Zhoo Yoon

    2013-01-01

    Background. The types of embryonic development probably provoke different paths of novel threadlike structure (NTS) development. The authors hypothesized that NTS may be easily observed on the surface of swine intestines by using trypan blue staining method and visualization under an optical microscope. Methods. General anesthesia was administered to 2 Yorkshire pigs. The abdominal walls of the pigs were carefully dissected along the medial alba. NTSs were identified on organ surfaces under a...

  18. Atypical depression in the structure of organic mental disorders (literature review)

    OpenAIRE

    Leonov S.F.; Shusterman T.Y.; Rokutov S.V.; Shornikov A.V.

    2014-01-01

    The review of literature presents current data on cli¬nical picture and diagnostics of atypical depression. Rubric “atypical depression” includes a variety of depressive states characterized by reactively caused changes of mood, sensitivity to interpersonal contacts, inverted vegetative and somatic symptoms such as increased appetite and hypersomnia. The article considers the place of atypical depression in the structure of organic mental disorders. Positions of foreign authors that produce a...

  19. Atypical depression in the structure of organic mental disorders (literature review).

    OpenAIRE

    Spirina, I. D.; Leonov, S. F.; Shusterman, T. Y.; Rokutov, S. V.; Shornikov, A. V.

    2014-01-01

    The review of literature presents current data on cli­nical picture and diagnostics of atypical depression. Rubric “atypical depression” includes a variety of depressive states characterized by reactively caused changes of mood, sensitivity to interpersonal contacts, inverted vegetative and somatic symptoms such as increased appetite and hypersomnia. The article considers the place of atypical depression in the structure of organic mental disorders. Positions of foreign authors that produce a...

  20. Controlled synthesis of organic nanophotonic materials with specific structures and compositions.

    Science.gov (United States)

    Cui, Qiu Hong; Zhao, Yong Sheng; Yao, Jiannian

    2014-10-29

    Organic nanomaterials have drawn great interest for their potential applications in high-speed miniaturized photonic integration due to their high photoluminescence quantum efficiency, structural processability, ultrafast photoresponse, and excellent property engineering. Based on the rational design on morphological and componential levels, a series of organic nanomaterials have been controllably synthesized in recent years, and their excitonic/photonic behaviors has been fine-tuned to steer the light flow for specific optical applications. This review presents a comprehensive summary of recent breakthroughs in the controlled synthesis of organic nanomaterials with specific structures and compositions, whose tunable photonic properties would provide a novel platform for multifunctional applications. First, we give a general overview of the tailored construction of novel nanostructures with various photonic properties. Then, we summarize the design and controllable synthesis of composite materials for the modulation of their functionalities. Subsequently, special emphasis is put on the fabrication of complex nanostructures towards wide applications in isolated photonic devices. We conclude with our personal viewpoints on the development directions in the novel design and controllable construction of organic nanomaterials for future applications in highly integrated photonic devices and chips.

  1. Structure and mechanical properties of selected protective systems in marine organisms.

    Science.gov (United States)

    Naleway, Steven E; Taylor, Jennifer R A; Porter, Michael M; Meyers, Marc A; McKittrick, Joanna

    2016-02-01

    Marine organisms have developed a wide variety of protective strategies to thrive in their native environments. These biological materials, although formed from simple biopolymer and biomineral constituents, take on many intricate and effective designs. The specific environmental conditions that shape all marine organisms have helped modify these materials into their current forms: complete hydration, and variation in hydrostatic pressure, temperature, salinity, as well as motion from currents and swells. These conditions vary throughout the ocean, being more consistent in the pelagic and deep benthic zones while experiencing more variability in the nearshore and shallows (e.g. intertidal zones, shallow bays and lagoons, salt marshes and mangrove forests). Of note, many marine organisms are capable of migrating between these zones. In this review, the basic building blocks of these structural biological materials and a variety of protective strategies in marine organisms are discussed with a focus on their structure and mechanical properties. Finally, the bioinspired potential of these biological materials is discussed. PMID:26652472

  2. Highly conductive transparent organic electrodes with multilayer structures for rigid and flexible optoelectronics.

    Science.gov (United States)

    Guo, Xiaoyang; Liu, Xingyuan; Lin, Fengyuan; Li, Hailing; Fan, Yi; Zhang, Nan

    2015-01-01

    Transparent electrodes are essential components for optoelectronic devices, such as touch panels, organic light-emitting diodes, and solar cells. Indium tin oxide (ITO) is widely used as transparent electrode in optoelectronic devices. ITO has high transparency and low resistance but contains expensive rare elements, and ITO-based devices have poor mechanical flexibility. Therefore, alternative transparent electrodes with excellent opto-electrical performance and mechanical flexibility will be greatly demanded. Here, organics are introduced into dielectric-metal-dielectric structures to construct the transparent electrodes on rigid and flexible substrates. We show that organic-metal-organic (OMO) electrodes have excellent opto-electrical properties (sheet resistance of below 10 Ω sq(-1) at 85% transmission), mechanical flexibility, thermal and environmental stabilities. The OMO-based polymer photovoltaic cells show performance comparable to that of devices based on ITO electrodes. This OMO multilayer structure can therefore be used to produce transparent electrodes suitable for use in a wide range of optoelectronic devices. PMID:26014889

  3. Unraveling the multiscale structural organization and connectivity of the human brain: the role of diffusion MRI

    Directory of Open Access Journals (Sweden)

    Matteo eBastiani

    2015-06-01

    Full Text Available The structural architecture and the anatomical connectivity of the human brain show different organizational principles at distinct spatial scales. Histological staining and light microscopy techniques have been widely used in classical neuroanatomical studies to unravel brain organization. Using such techniques is a laborious task performed on 2-dimensional histological sections by skilled anatomists possibly aided by semi-automated algorithms. With the recent advent of modern magnetic resonance imaging (MRI contrast mechanisms, cortical layers and columns can now be reliably identified and their structural properties quantified post mortem. These developments are allowing the investigation of neuroanatomical features of the brain at a spatial resolution that could be interfaced with that of histology. Diffusion MRI and tractography techniques, in particular, have been used to probe the architecture of both white and gray matter in three dimensions. Combined with mathematical network analysis, these techniques are increasingly influential in the investigation of the macro-, meso- and microscopic organization of brain connectivity and anatomy, both in vivo and ex vivo. Diffusion MRI-based techniques in combination with histology approaches can therefore support the endeavor of creating multimodal atlases that take into account the different spatial scales or levels on which the brain is organized. The aim of this review is to illustrate and discuss the structural architecture and the anatomical connectivity of the human brain at different spatial scales and how recently developed diffusion MRI techniques can help investigate these.

  4. Composite organic-inorganic butterfly scales: production of photonic structures with atomic layer deposition.

    Science.gov (United States)

    Gaillot, Davy P; Deparis, Olivier; Welch, Victoria; Wagner, Brent K; Vigneron, Jean Pol; Summers, Christopher J

    2008-09-01

    Recent advances in the photonics and optics industries have produced great demand for ever more sophisticated optical devices, such as photonic crystals. However, photonic crystals are notoriously difficult to manufacture. Increasingly, therefore, researchers have turned towards naturally occurring photonic structures for inspiration and a wide variety of elaborate techniques have been attempted to copy and harness biological processes to manufacture artificial photonic structures. Here, we describe a simple, direct process for producing an artificial photonic device by using a naturally occurring structure from the wings of the butterfly Papilio blumei as a template and low-temperature atomic layer deposition of TiO2 to create a faithful cast of the structure. The optical properties of the organic-inorganic diffraction structures produced are assessed by normal-incidence specular reflectance and found to be well described by multilayer computation method using a two-dimensional photonic crystal model. Depending on the structural integrity of the initially sealed scale, it was found possible not only to replicate the outer but also the inner and more complex surfaces of the structure, each resulting in distinct multicolor optical behavior as revealed by experimental and theoretical data. In this paper, we also explore tailoring the process to design composite skeleton architectures with desired optical properties and integrated multifunctional (mechanical, thermal, optical, fluidic) properties. PMID:18851080

  5. Self-organized structures in a superorganism: do ants “behave” like molecules?

    Science.gov (United States)

    Detrain, Claire; Deneubourg, Jean-Louis

    2006-09-01

    While the striking structures (e.g. nest architecture, trail networks) of insect societies may seem familiar to many of us, the understanding of pattern formation still constitutes a challenging problem. Over the last two decades, self-organization has dramatically changed our view on how collective decision-making and structures may emerge out of a population of ant workers having each their own individuality as well as a limited access to information. A variety of collective behaviour spontaneously outcome from multiple interactions between nestmates, even when there is no directing influence imposed by an external template, a pacemaker or a leader. By focussing this review on foraging structures, we show that ant societies display some properties which are usually considered in physico-chemical systems, as typical signatures of self-organization. We detail the key role played by feed-back loops, fluctuations, number of interacting units and sensitivity to environmental factors in the emergence of a structured collective behaviour. Nonetheless, going beyond simple analogies with non-living self-organized patterns, we stress on the specificities of social structures made of complex living units of which the biological features have been selected throughout the evolution depending on their adaptive value. In particular, we consider the ability of each ant individual to process information about environmental and social parameters, to accordingly tune its interactions with nestmates and ultimately to determine the final pattern emerging at the collective level. We emphasize on the parsimony and simplicity of behavioural rules at the individual level which allow an efficient processing of information, energy and matter within the whole colony.

  6. The strength of a calcified tissue depends in part on the molecular structure and organization of its constituent mineral crystals in their organic matrix

    Science.gov (United States)

    Landis, W. J.

    1995-01-01

    High-voltage electron-microscopic tomographic (3D) studies of the ultrastructural interaction between mineral and organic matrix in a variety of calcified tissues reveal different crystal structural and organizational features in association with their respective organic matrices. In brittle or weak pathologic or ectopic calcifications, including examples of osteogenesis imperfecta, calciphylaxis, calcergy, and dermatomyositis, hydroxyapatite crystals occur in various sizes and shapes and are oriented and aligned with respect to collagen in a manner which is distinct from that found in normal calcified tissues. A model of collagen-mineral interaction is proposed which may account for the observed crystal structures and organization. The results indicate that the ultimate strength, support, and other mechanical properties provided by a calcified tissue are dependent in part upon the molecular structure and arrangement of its constituent mineral crystals within their organic matrix.

  7. Structure transformations of endocrine system organs during adaptation to increased radioactivity

    International Nuclear Information System (INIS)

    It is well known that during ecological monitoring of contaminated territories registration of early abnormalities in an organism is hampered by man-caused influence of habitat. Under these circumstances study of both structural and functional changes in organs and tissues of rodents inhabiting radioactive contaminated territories is of great importance. Study of structural features of endocrine glands, hormones of which trigger the process of active adaptive changes in an organism, is very important in radioecological surveys. Basing on long-term study of voles we have determined that long-term living by rodents on the territories characterized by increased natural and artificial radioactivity (radium contaminated fields in the Komi Republic and 30-km zone of Chernobyl APS) substantially influences morpho-functional state of endocrine system organs, causing quantitative and qualitative changes. It is demonstrated that population processes modify biological consequences of small doze chronic ionizing radiation in habitat. We noticed the following: high heterogeneity of histological changes of thyroid gland and adrenal gland as a response to radioactive habitat contamination; disorder of interconnection among different links of endocrine system; dependence of radiation effects on gender, age, degree and character of radiation contamination of a habitat as well as duration of radioactive influence. We have got data on morphological characteristics of thyroid gland and adrenal gland during different phases of population amount of this kind of rodents. It was discovered that effectiveness of radiation influence is not the same during different periods of population cycle. Presence of voles on the territories characterized by increased radioactivity causes chronic tension of adrenal cortex (increasing of the organ mass, enlarging of thickness of zona fasciculata and zona reticularis). Destructive-necrotic processes combine with manifestation of reparative regeneration

  8. Structure transformations of endocrine system organs during adaptation to increased radioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Ermakova, O.V. [Institute of Biology, Komi Scientific Centre, Ural Division of Russian Academy of Sciences, Syktyvkar (Russian Federation)

    2004-07-01

    It is well known that during ecological monitoring of contaminated territories registration of early abnormalities in an organism is hampered by man-caused influence of habitat. Under these circumstances study of both structural and functional changes in organs and tissues of rodents inhabiting radioactive contaminated territories is of great importance. Study of structural features of endocrine glands, hormones of which trigger the process of active adaptive changes in an organism, is very important in radioecological surveys. Basing on long-term study of voles we have determined that long-term living by rodents on the territories characterized by increased natural and artificial radioactivity (radium contaminated fields in the Komi Republic and 30-km zone of Chernobyl APS) substantially influences morpho-functional state of endocrine system organs, causing quantitative and qualitative changes. It is demonstrated that population processes modify biological consequences of small doze chronic ionizing radiation in habitat. We noticed the following: high heterogeneity of histological changes of thyroid gland and adrenal gland as a response to radioactive habitat contamination; disorder of interconnection among different links of endocrine system; dependence of radiation effects on gender, age, degree and character of radiation contamination of a habitat as well as duration of radioactive influence. We have got data on morphological characteristics of thyroid gland and adrenal gland during different phases of population amount of this kind of rodents. It was discovered that effectiveness of radiation influence is not the same during different periods of population cycle. Presence of voles on the territories characterized by increased radioactivity causes chronic tension of adrenal cortex (increasing of the organ mass, enlarging of thickness of zona fasciculata and zona reticularis). Destructive-necrotic processes combine with manifestation of reparative regeneration

  9. The Structure of Neurexin 1[alpha] Reveals Features Promoting a Role as Synaptic Organizer

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Fang; Venugopal, Vandavasi; Murray, Beverly; Rudenko, Gabby (Michigan)

    2014-10-02

    {alpha}-Neurexins are essential synaptic adhesion molecules implicated in autism spectrum disorder and schizophrenia. The {alpha}-neurexin extracellular domain consists of six LNS domains interspersed by three EGF-like repeats and interacts with many different proteins in the synaptic cleft. To understand how {alpha}-neurexins might function as synaptic organizers, we solved the structure of the neurexin 1{alpha} extracellular domain (n1{alpha}) to 2.65 {angstrom}. The L-shaped molecule can be divided into a flexible repeat I (LNS1-EGF-A-LNS2), a rigid horseshoe-shaped repeat II (LNS3-EGF-B-LNS4) with structural similarity to so-called reelin repeats, and an extended repeat III (LNS5-EGF-B-LNS6) with controlled flexibility. A 2.95 {angstrom} structure of n1{alpha} carrying splice insert SS3 in LNS4 reveals that SS3 protrudes as a loop and does not alter the rigid arrangement of repeat II. The global architecture imposed by conserved structural features enables {alpha}-neurexins to recruit and organize proteins in distinct and variable ways, influenced by splicing, thereby promoting synaptic function.

  10. Structure Prediction Based on Hydrophobic to Hydrophilic Volume Ratios in Small Molecule Amphiphilic Organic Crystals

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The structure type for the crystal of 4,4'-bis-(2-hydroxy-ethoxyl)-biphenyl 1 has been predicted by using the previously developed interfacial model for small organic molecules. Based on the calculated hydrophobic to hydrophilic volume of 1, this model predicts the crystal structure to be of lamellar or bicontinuous type, which has been confirmed by the X-ray single-crystal structure analysis (C20H26O6, monoclinic, P21/c, a = 16.084(1), b = 6.0103(4), c = 9.6410(7)(A), β = 103.014(2)°, V = 908.1(1)(A)3, Z = 2, Dc = 1.325 g/cm3, F(000)=388, μ = 0.097 mm-1, MoKα radiation, λ = 0.71073 (A), R = 0.0382 and wR = 0.0882 with I > 2σ(I) for 7121 reflections collected, 1852 unique reflections and 170 parameters). As predicted, the hydrophobic and hydrophilic portions of 1 form in the lamellae. The same interfacial model is applied to other amphilphilic small molecule organic systems for structural type prediction.

  11. The electro-structural behaviour of yarn-like carbon nanotube fibres immersed in organic liquids

    Science.gov (United States)

    Terrones, Jeronimo; Windle, Alan H.; Elliott, James A.

    2014-10-01

    Yarn-like carbon nanotube (CNT) fibres are a hierarchically-structured material with a variety of promising applications such as high performance composites, sensors and actuators, smart textiles, and energy storage and transmission. However, in order to fully realize these possibilities, a more detailed understanding of their interactions with the environment is required. In this work, we describe a simplified representation of the hierarchical structure of the fibres from which several mathematical models are constructed to explain electro-structural interactions of fibres with organic liquids. A balance between the elastic and surface energies of the CNT bundle network in different media allows the determination of the maximum lengths that open junctions can sustain before collapsing to minimize the surface energy. This characteristic length correlates well with the increase of fibre resistance upon immersion in organic liquids. We also study the effect of charge accumulation in open interbundle junctions and derive expressions to describe experimental data on the non-ohmic electrical behaviour of fibres immersed in polar liquids. Our analyses suggest that the non-ohmic behaviour is caused by progressively shorter junctions collapsing as the voltage is increased. Since our models are not based on any property unique to carbon nanotubes, they should also be useful to describe other hierarchical structures.

  12. The electro-structural behaviour of yarn-like carbon nanotube fibres immersed in organic liquids

    International Nuclear Information System (INIS)

    Yarn-like carbon nanotube (CNT) fibres are a hierarchically-structured material with a variety of promising applications such as high performance composites, sensors and actuators, smart textiles, and energy storage and transmission. However, in order to fully realize these possibilities, a more detailed understanding of their interactions with the environment is required. In this work, we describe a simplified representation of the hierarchical structure of the fibres from which several mathematical models are constructed to explain electro-structural interactions of fibres with organic liquids. A balance between the elastic and surface energies of the CNT bundle network in different media allows the determination of the maximum lengths that open junctions can sustain before collapsing to minimize the surface energy. This characteristic length correlates well with the increase of fibre resistance upon immersion in organic liquids. We also study the effect of charge accumulation in open interbundle junctions and derive expressions to describe experimental data on the non-ohmic electrical behaviour of fibres immersed in polar liquids. Our analyses suggest that the non-ohmic behaviour is caused by progressively shorter junctions collapsing as the voltage is increased. Since our models are not based on any property unique to carbon nanotubes, they should also be useful to describe other hierarchical structures. (paper)

  13. Novel threadlike structures may be present on the large animal organ surface: evidence in Swine model.

    Science.gov (United States)

    Bae, Kyoung-Hee; Park, Sang Hyun; Lee, Byung-Cheon; Nam, Min-Ho; Yoon, Ji Woong; Kwon, Hee-Min; Yoon, Seung Zhoo

    2013-01-01

    Background. The types of embryonic development probably provoke different paths of novel threadlike structure (NTS) development. The authors hypothesized that NTS may be easily observed on the surface of swine intestines by using trypan blue staining method and visualization under an optical microscope. Methods. General anesthesia was administered to 2 Yorkshire pigs. The abdominal walls of the pigs were carefully dissected along the medial alba. NTSs were identified on organ surfaces under a stereoscopic microscope after trypan blue staining. Isolated NTS specimens obtained from the large intestine were subjected to 4',6-diamidino-2-phenylindole (DAPI) staining and observed using the polarized light microscopy to confirm whether the obtained structure fits the definition of NTS. Results. We found elastic, semitransparent threadlike structures (forming a network structure) that had a milky-white color in situ and in vivo in swine large intestines. The samples showed distinct extinction of polarized light at every 90 degrees, and nucleus was shown to be rod shaped by DAPI staining, indicating that they meet the criteria of NTS. Conclusion. We used a swine model to demonstrate that NTS may be present on large animal organ surfaces. Our results may permit similar studies by using human specimens. PMID:23762159

  14. Novel Threadlike Structures May Be Present on the Large Animal Organ Surface: Evidence in Swine Model

    Directory of Open Access Journals (Sweden)

    Kyoung-Hee Bae

    2013-01-01

    Full Text Available Background. The types of embryonic development probably provoke different paths of novel threadlike structure (NTS development. The authors hypothesized that NTS may be easily observed on the surface of swine intestines by using trypan blue staining method and visualization under an optical microscope. Methods. General anesthesia was administered to 2 Yorkshire pigs. The abdominal walls of the pigs were carefully dissected along the medial alba. NTSs were identified on organ surfaces under a stereoscopic microscope after trypan blue staining. Isolated NTS specimens obtained from the large intestine were subjected to 4′,6-diamidino-2-phenylindole (DAPI staining and observed using the polarized light microscopy to confirm whether the obtained structure fits the definition of NTS. Results. We found elastic, semitransparent threadlike structures (forming a network structure that had a milky-white color in situ and in vivo in swine large intestines. The samples showed distinct extinction of polarized light at every 90 degrees, and nucleus was shown to be rod shaped by DAPI staining, indicating that they meet the criteria of NTS. Conclusion. We used a swine model to demonstrate that NTS may be present on large animal organ surfaces. Our results may permit similar studies by using human specimens.

  15. Molecular crowding of collagen: a pathway to produce highly-organized collagenous structures.

    Science.gov (United States)

    Saeidi, Nima; Karmelek, Kathryn P; Paten, Jeffrey A; Zareian, Ramin; DiMasi, Elaine; Ruberti, Jeffrey W

    2012-10-01

    Collagen in vertebrate animals is often arranged in alternating lamellae or in bundles of aligned fibrils which are designed to withstand in vivo mechanical loads. The formation of these organized structures is thought to result from a complex, large-area integration of individual cell motion and locally-controlled synthesis of fibrillar arrays via cell-surface fibripositors (direct matrix printing). The difficulty of reproducing such a process in vitro has prevented tissue engineers from constructing clinically useful load-bearing connective tissue directly from collagen. However, we and others have taken the view that long-range organizational information is potentially encoded into the structure of the collagen molecule itself, allowing the control of fibril organization to extend far from cell (or bounding) surfaces. We here demonstrate a simple, fast, cell-free method capable of producing highly-organized, anistropic collagen fibrillar lamellae de novo which persist over relatively long-distances (tens to hundreds of microns). Our approach to nanoscale organizational control takes advantage of the intrinsic physiochemical properties of collagen molecules by inducing collagen association through molecular crowding and geometric confinement. To mimic biological tissues which comprise planar, aligned collagen lamellae (e.g. cornea, lamellar bone or annulus fibrosus), type I collagen was confined to a thin, planar geometry, concentrated through molecular crowding and polymerized. The resulting fibrillar lamellae show a striking resemblance to native load-bearing lamellae in that the fibrils are small, generally aligned in the plane of the confining space and change direction en masse throughout the thickness of the construct. The process of organizational control is consistent with embryonic development where the bounded planar cell sheets produced by fibroblasts suggest a similar confinement/concentration strategy. Such a simple approach to nanoscale

  16. Structural Analysis of Layered Polymer Crystals and Application to Photofunctional Materials Using Organic Intercalation

    Institute of Scientific and Technical Information of China (English)

    Shinya Oshita; Akikazu Matsumoto

    2005-01-01

    @@ 1Introduction We reported that layered polymer crystals are obtained by the topochemical polymerization of 1,3-diene monomers and provided as host material for organic intercalation[1]. For intercalation using various long-alkyl amines as the guest species, its reaction behavior, mechanism, characteristics, and potential to application have been clarified[2]. We also succeeded in the synthesis of several host layered polymer crystals with different tacticities and layer structures[3]. We describe here intercalation using various stereoregular poly(muconic acid)s (PMA) and n-alkylamines as the host and guest compounds, respectively. The reaction behavior and the layered structure of the obtained ammonium polymers are discussed from the viewpoint of stereochemical structure of the host polymers.

  17. Atypical depression in the structure of organic mental disorders (literature review

    Directory of Open Access Journals (Sweden)

    Leonov S.F.

    2014-09-01

    Full Text Available The review of literature presents current data on cli¬nical picture and diagnostics of atypical depression. Rubric “atypical depression” includes a variety of depressive states characterized by reactively caused changes of mood, sensitivity to interpersonal contacts, inverted vegetative and somatic symptoms such as increased appetite and hypersomnia. The article considers the place of atypical depression in the structure of organic mental disorders. Positions of foreign authors that produce atypical depression as a clinical entity in the structure of Bipolar affective disorder II type are represented, the views of other authors on the structure of atypical depression are considered. The analysis of national concept of non-circular depression is carried out. Questions of atypical affective conditions acquire special significance due to preparation of International Classification of Diseases of the 11th revision, because inclusion in it of Bipolar affective disorder II type, a manifestation of which is considered to be atypical depressions, is under discussion.

  18. Chlorine adlayer-templated growth of a hybrid inorganic-organic layered structure on Au(111)

    Science.gov (United States)

    Rzeźnicka, I. I.; Horino, H.; Yagyu, K.; Suzuki, T.; Kajimoto, S.; Fukumura, H.

    2016-10-01

    Growth of a hybrid inorganic-organic layered structure on the Au(111) surface using a one-step solution growth is reported. The hybrid structure is consist of 4,4‧-bipyridine [4,4‧-BiPyH2]2 + cations, Cl anions and Au adatoms, provided from substrate by means of the adsorbate-induced surface phase transition of a surface reconstruction. Its surface and bulk structures were characterized by scanning tunneling microscopy (STM), secondary ion mass spectrometry (SIMS), and Raman spectroscopy. STM results reveal growth of the first [4,4‧-BiPyH2]2 + layer on top of the p(√{ 3} ×√{ 3})" separators=", R 30 ° chlorine overlayer formed on the Au(111) surface. These two layers are found to provide a platform for a following three-dimensional growth facilitated by hydrogen bonding, aurophilic and π-π stacking interactions.

  19. A novel series of isoreticular metal organic frameworks: Realizing metastable structures by liquid phase epitaxy

    KAUST Repository

    Liu, Jinxuan

    2012-12-04

    A novel class of metal organic frameworks (MOFs) has been synthesized from Cu-acetate and dicarboxylic acids using liquid phase epitaxy. The SURMOF-2 isoreticular series exhibits P4 symmetry, for the longest linker a channel-size of 3 3 nm2 is obtained, one of the largest values reported for any MOF so far. High quality, ab-initio electronic structure calculations confirm the stability of a regular packing of (Cu++) 2-carboxylate paddle-wheel planes with P4 symmetry and reveal, that the SURMOF-2 structures are in fact metastable, with a fairly large activation barrier for the transition to the bulk MOF-2 structures exhibiting a lower, twofold (P2 or C2) symmetry. The theoretical calculations also allow identifying the mechanism for the low-temperature epitaxial growth process and to explain, why a synthesis of this highly interesting, new class of high-symmetry, metastable MOFs is not possible using the conventional solvothermal process.

  20. Evolution of self-organization in nano-structured PVD coatings under extreme tribological conditions

    International Nuclear Information System (INIS)

    Highlights: • The evolution of self-organization under extreme frictional conditions has been studied. • Comprehensive characterization of the tribo-films was made using various surface analytical techniques. • During the running-in stage, mullite tribo-ceramics predominate on the surface of the nano-multilayer coating, establishing a functional hierarchy within the layer of tribo-films. • It is possible to control tribo-film evolution during self-organization by means of an increase in structural complexity and the non-equilibrium state of the surface engineered layer. - Abstract: The evolution of the self-organization process where dissipative structures are formed under the extreme frictional conditions associated with high performance dry machining of hardened steels has been studied in detail. The emphasis was on the progressive studies of surface transformations within multilayer and monolayer TiAlCrSiYN-based PVD coatings during the running-in stage of wear when self-organization process occurs. The coating layer was characterized by high resolution electron energy-loss spectroscopy (HREELS). It is shown that the nano-multilayer coating possesses higher non-equilibrium structure in comparison to the monolayer. Comprehensive studies of the tribo-films (dissipative structures) formed on the friction surface were made using a number of advanced surface characterization techniques such as X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge structure (XANES). The data obtained for the tribo-films was combined with the detailed TEM studies of the structural and phase transformations within the underlying coating layer. This data was related to the micro-mechanical characteristics of the coating layer and its wear resistance. It was demonstrated that the evolution of the self-organization process is strongly controlled by the characteristics of the tribo-films formed at different stages of the wear process. Within running-in stage (after

  1. Evolution of self-organization in nano-structured PVD coatings under extreme tribological conditions

    Energy Technology Data Exchange (ETDEWEB)

    Fox-Rabinovich, G., E-mail: gfox@mcmaster.ca [Department of Mechanical Engineering, McMaster University, 1280 Main St. W., Hamilton, ON, Canada L8S 4L7 (Canada); Kovalev, A. [Surface Phenomena Researches Group, CNIICHERMET, 9/23, 2-nd Baumanskaya Street, Moscow 105005 (Russian Federation); Aguirre, M.H. [Laboratory of Advanced Microscopy, Institute of Nanoscience of Aragón, University of Zaragoza, 50018 Zaragoza (Spain); Yamamoto, K. [Materials Research Laboratory, Kobe Steel Ltd, 1-5-5 Takatsuda-dai, Nishi-ku, Kobe 651-2271, Hyogo (Japan); Veldhuis, S. [Department of Mechanical Engineering, McMaster University, 1280 Main St. W., Hamilton, ON, Canada L8S 4L7 (Canada); Gershman, I. [All-Russian Railway Research Institute, 10 Third Mytishchinskaya Street, Moscow 29851 (Russian Federation); Rashkovskiy, A. [Surface Phenomena Researches Group, CNIICHERMET, 9/23, 2-nd Baumanskaya Street, Moscow 105005 (Russian Federation); Endrino, J.L. [Albengoa Research, Energia Solar 1, Palmas Altas, Seville 41014 (Spain); Beake, B. [Micro Materials Limited, Willow House, Yale Business Village, Ellice Way, Wrexham LL13 7YL (United Kingdom); Dosbaeva, G. [Department of Mechanical Engineering, McMaster University, 1280 Main St. W., Hamilton, ON, Canada L8S 4L7 (Canada); Wainstein, D. [Surface Phenomena Researches Group, CNIICHERMET, 9/23, 2-nd Baumanskaya Street, Moscow 105005 (Russian Federation); Yuan, Junifeng; Bunting, J.W. [Department of Mechanical Engineering, McMaster University, 1280 Main St. W., Hamilton, ON, Canada L8S 4L7 (Canada)

    2014-04-01

    Highlights: • The evolution of self-organization under extreme frictional conditions has been studied. • Comprehensive characterization of the tribo-films was made using various surface analytical techniques. • During the running-in stage, mullite tribo-ceramics predominate on the surface of the nano-multilayer coating, establishing a functional hierarchy within the layer of tribo-films. • It is possible to control tribo-film evolution during self-organization by means of an increase in structural complexity and the non-equilibrium state of the surface engineered layer. - Abstract: The evolution of the self-organization process where dissipative structures are formed under the extreme frictional conditions associated with high performance dry machining of hardened steels has been studied in detail. The emphasis was on the progressive studies of surface transformations within multilayer and monolayer TiAlCrSiYN-based PVD coatings during the running-in stage of wear when self-organization process occurs. The coating layer was characterized by high resolution electron energy-loss spectroscopy (HREELS). It is shown that the nano-multilayer coating possesses higher non-equilibrium structure in comparison to the monolayer. Comprehensive studies of the tribo-films (dissipative structures) formed on the friction surface were made using a number of advanced surface characterization techniques such as X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge structure (XANES). The data obtained for the tribo-films was combined with the detailed TEM studies of the structural and phase transformations within the underlying coating layer. This data was related to the micro-mechanical characteristics of the coating layer and its wear resistance. It was demonstrated that the evolution of the self-organization process is strongly controlled by the characteristics of the tribo-films formed at different stages of the wear process. Within running-in stage (after

  2. Self-Organization of Urea-Based Oligomers from Structure to Function

    Institute of Scientific and Technical Information of China (English)

    G. Guichard

    2005-01-01

    @@ 1Introduction The remarkable and highly diverse biological activities exhibited by proteins rely on the unique capacity of these intrinsically flexible α-polypeptide chains to fold into well ordered and compact structures. The formation of protein tertiary and quaternary structures is attainable only with a small set of distinct secondary structural elements: i) sheets, ii) helices, and iii) turns.These fascinating structures have undoubtedly stimulated chemists to elaborate new synthetic oligomeric materials that could self-organize spontaneously but in a controlled fashion to form defined structural motifs.In the field of biomimetic chemistry, seminal work by several research groups has demonstrated that properties such as folding and structural diversity are not restricted to natural linear α-polypeptides but are shared by a number of aliphatic (e. g. β- and γ-peptides)[1-3] and aromatic[4] oligo-amides. The predictability of folding in these oligomeric strands can be integrated to develop molecules with function (e. g. in biology).Aknowledgements:

  3. Structural Organization of Insulin Fibrils Based on Polarized Raman Spectroscopy: Evaluation of Existing Models.

    Science.gov (United States)

    Sereda, Valentin; Sawaya, Michael R; Lednev, Igor K

    2015-09-01

    Many different proteins undergo misfolding and self-assemble into amyloid fibrils, resulting in a range of neurodegenerative diseases. The limitations of conventional methods of structural biology for fibril characterization have led to the use of polarized Raman spectroscopy for obtaining quantitative structural information regarding the organization of amyloid fibrils. Herein, we report the orientation of selected chemical groups and secondary structure elements in aligned insulin fibrils, including β-sheets, which possess a high level of orientation in the cross-β core, and α-helices in the disordered portions of the fibrils. Strong orientation of disulfide bonds in amyloid fibrils was also revealed, indicating their association with the fibril core. The determined orientation of chemical groups provides strong constraints for modeling the overall structure of amyloid fibrils, including the core and disordered parts. The developed methodology allows for the validation of structural models proposed in the literature for amyloid fibrils. Specifically, the polarized Raman data obtained herein strongly agreed with two insulin fibril models (Jiménez et al., Proc. Natl. Acad. Sci. U. S. A. 2002, 99, 9196-9201 and Ivanova et al., Proc. Natl. Acad. Sci. U. S. A. 2009, 106, 18990-18995) yet revealed significant qualitative and quantitative differences. This work demonstrates the great potential of polarized Raman spectroscopy for structural characterization of anisotropic biological species.

  4. "Just as the Structural Formula Does": Names, Diagrams, and the Structure of Organic Chemistry at the 1892 Geneva Nomenclature Congress.

    Science.gov (United States)

    Hepler-Smith, Evan

    2015-02-01

    At the Geneva Nomenclature Congress of 1892, some of the foremost organic chemists of the late nineteenth century crafted a novel relationship between chemical substances, chemical diagrams, and chemical names that has shaped practices of chemical representation ever since. During the 1880s, the French chemist Charles Friedel organised the nomenclature reform effort that culminated in the Geneva Congress; in the disorderly nomenclature of German synthetic chemistry, Friedel saw an opportunity to advance French national interests and his own pedagogical goals. Friedel and a group of close colleagues reconceived nomenclature as a unified field, in which all chemical names ought to relate clearly to one another and to the structure of the compounds they represented. The German chemist Adolf von Baeyer went a step farther, arguing for names that precisely and uniquely corresponded to the structural formula of each compound, tailored for use in chemical dictionaries and handbooks. Baeyer's vision prevailed at the Geneva Congress, which consequently codified rules for rigorously mapping structural formulas into names, resulting in names that faithfully represented the features of these diagrams but not always the chemical behaviour of the compounds themselves. This approach ultimately limited both the number of chemical compounds that the Geneva rules were able to encompass and the breadth of their application. However, the relationship between diagram and name established at the Geneva Congress became the foundation not only of subsequent systems of chemical nomenclature but of methods of organising information that have supported the modern chemical sciences.

  5. Quantitative structure-activity relationships (QSARs) for the transformation of organic micropollutants during oxidative water treatment.

    Science.gov (United States)

    Lee, Yunho; von Gunten, Urs

    2012-12-01

    Various oxidants such as chlorine, chlorine dioxide, ferrate(VI), ozone, and hydroxyl radicals can be applied for eliminating organic micropollutant by oxidative transformation during water treatment in systems such as drinking water, wastewater, and water reuse. Over the last decades, many second-order rate constants (k) have been determined for the reaction of these oxidants with model compounds and micropollutants. Good correlations (quantitative structure-activity relationships or QSARs) are often found between the k-values for an oxidation reaction of closely related compounds (i.e. having a common organic functional group) and substituent descriptor variables such as Hammett or Taft sigma constants. In this study, we developed QSARs for the oxidation of organic and some inorganic compounds and organic micropollutants transformation during oxidative water treatment. A number of 18 QSARs were developed based on overall 412 k-values for the reaction of chlorine, chlorine dioxide, ferrate, and ozone with organic compounds containing electron-rich moieties such as phenols, anilines, olefins, and amines. On average, 303 out of 412 (74%) k-values were predicted by these QSARs within a factor of 1/3-3 compared to the measured values. For HO(·) reactions, some principles and estimation methods of k-values (e.g. the Group Contribution Method) are discussed. The developed QSARs and the Group Contribution Method could be used to predict the k-values for various emerging organic micropollutants. As a demonstration, 39 out of 45 (87%) predicted k-values were found within a factor 1/3-3 compared to the measured values for the selected emerging micropollutants. Finally, it is discussed how the uncertainty in the predicted k-values using the QSARs affects the accuracy of prediction for micropollutant elimination during oxidative water treatment. PMID:22939392

  6. Effects of low dose acrylamide on the rat reproductive organs structure, fertility and gene integrity

    Institute of Scientific and Technical Information of China (English)

    Saleh Alkarim; Sufyan Elassouli; Soad Ali; Nasra Ayuob; Zaki Elassouli

    2015-01-01

    Objective:To assesses the effects of long term exposure to low dose of acrylamide (0.4 μg /g) in post-weaning Sprague-Dawley rats on the structure of the reproductive organ as well as DNA integrity. Methods:The histological changes in the male and female reproductive organs the morphological changes in sperms as well as the genotoxic effect of acrylamide were assessed. The effect acrylamide on pregnancy outcome was evaluated.Results:Testes of acrylamide-fed rats showed decreased number of seminiferous tubules containing mature sperms and degenerative changes in sperm germ cell layers. Some sperms of epididymal cauda showed head deformity. In female, acrylamide included cystic ovarian changes, degenerative changes of zona pelluida, granulosa cells and oocytes. Post implantation loss and decrease in the number of full term fetuses were detected. Resorption sites showed necrotic fetal tissue with vacuolation of amniotic cells.Conclusion:Acrylamide cause harmful effect on the reproductive organ structure, fertility and cause extensive DNA damage in peripheral blood lymphocytes.

  7. Evidence of a new form of self-organization in DBD Plasmas: the quincunx structure

    International Nuclear Information System (INIS)

    Self-organized, stable or dynamic, filamentary structures are known to form in dielectric barrier discharges (DBDs) operating in a glow regime. The common 'classical' understanding of stable filamentary structures in DBDs is that a glow-discharge filament forms at each half cycle of the sinusoidal applied voltage at the same spatial location along the dielectric surface. The 'memory' charges deposited by the previous filament on the dielectric surfaces are responsible for the ignition of a new discharge at the same location. On the other hand, the formation of a filamentary discharge at a given location inhibits discharge development in its vicinity because of charge spreading along the dielectric surface leading to a decrease in the gap voltage in this region. In this paper we show using experiments and models that another self-organized filamentary regime is possible and coexists with the 'classical' regime. In this regime, never reported before, discharge filaments at successive half cycles do not occur at the same location but are shifted by half a spatial period. We call this regime the 'quincunx' regime. We also show that the mechanisms of this regime may be responsible for some dynamical aspects of self-organization in DBDs. (fast track communication)

  8. Structural investigations of self-assembled monolayers for organic electronics: results from X-ray reflectivity.

    Science.gov (United States)

    Khassanov, Artoem; Steinrück, Hans-Georg; Schmaltz, Thomas; Magerl, Andreas; Halik, Marcus

    2015-07-21

    Self-assembled monolayers (SAMs) have been established as crucial interlayers and electronically active layers in organic electronic devices, such as organic light emitting diodes (OLEDs), organic photovoltaics (OPVs), organic thin film transistors (OTFTs), and nonvolatile memories (NVMs). The use of self-assembling functionalized organic molecules is beneficial due to mainly three advantages compared with common thin film deposition approaches. (1) Molecular self-assembly occurs with surface selectivity, determined by the interaction between the functional anchor group of the organic molecules and the target surface. (2) The film thickness of the resulting layers is perfectly controllable on the angstrom scale, due to the self-terminating film formation to only a single molecular layer. And finally, (3) the wide variability in the chemical structure of such molecules enables different SAM functionalities for devices, ranging from electrical insulation to charge storage to charge transport. The SAM approach can be further expanded by employing several functionalized molecules to create mixed SAMs with consequently mixed properties. The function of SAMs in devices depends not only on the chemical structure of the molecules but also on their final arrangement and orientation on the surface. A reliable and nondestructive in-depth characterization of SAMs on nonconductive oxide surfaces is still challenging because of the very small thickness and the impracticality of methods such as scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS). In this Account, we illustrate how X-ray reflectivity (XRR) provides analytical access to major questions of SAM composition, morphology, and even formation by means of investigations of pure and mixed SAMs based on phosphonic acids (PAs) of various chain structures on flat alumina (AlOx) surfaces. XRR is an analytical method that provides access to spatially averaged structural depth profiles over a relatively

  9. Synthesis, structure, and opto-electronic properties of organic-based nanoscale heterojunctions

    Science.gov (United States)

    Rezek, Bohuslav; Čermák, Jan; Kromka, Alexander; Ledinský, Martin; Hubík, Pavel; Mareš, Jiří J.; Purkrt, Adam; Cimrová, Vĕra; Fejfar, Antonín; Kočka, Jan

    2011-12-01

    Enormous research effort has been put into optimizing organic-based opto-electronic systems for efficient generation of free charge carriers. This optimization is mainly due to typically high dissociation energy (0.1-1 eV) and short diffusion length (10 nm) of excitons in organic materials. Inherently, interplay of microscopic structural, chemical, and opto-electronic properties plays crucial role. We show that employing and combining advanced scanning probe techniques can provide us significant insight into the correlation of these properties. By adjusting parameters of contact- and tapping-mode atomic force microscopy (AFM), we perform morphologic and mechanical characterizations (nanoshaving) of organic layers, measure their electrical conductivity by current-sensing AFM, and deduce work functions and surface photovoltage (SPV) effects by Kelvin force microscopy using high spatial resolution. These data are further correlated with local material composition detected using micro-Raman spectroscopy and with other electronic transport data. We demonstrate benefits of this multi-dimensional characterizations on (i) bulk heterojunction of fully organic composite films, indicating differences in blend quality and component segregation leading to local shunts of photovoltaic cell, and (ii) thin-film heterojunction of polypyrrole (PPy) electropolymerized on hydrogen-terminated diamond, indicating covalent bonding and transfer of charge carriers from PPy to diamond.

  10. Synthesis, structure, and opto-electronic properties of organic-based nanoscale heterojunctions

    Directory of Open Access Journals (Sweden)

    Cimrová Vĕra

    2011-01-01

    Full Text Available Abstract Enormous research effort has been put into optimizing organic-based opto-electronic systems for efficient generation of free charge carriers. This optimization is mainly due to typically high dissociation energy (0.1-1 eV and short diffusion length (10 nm of excitons in organic materials. Inherently, interplay of microscopic structural, chemical, and opto-electronic properties plays crucial role. We show that employing and combining advanced scanning probe techniques can provide us significant insight into the correlation of these properties. By adjusting parameters of contact- and tapping-mode atomic force microscopy (AFM, we perform morphologic and mechanical characterizations (nanoshaving of organic layers, measure their electrical conductivity by current-sensing AFM, and deduce work functions and surface photovoltage (SPV effects by Kelvin force microscopy using high spatial resolution. These data are further correlated with local material composition detected using micro-Raman spectroscopy and with other electronic transport data. We demonstrate benefits of this multi-dimensional characterizations on (i bulk heterojunction of fully organic composite films, indicating differences in blend quality and component segregation leading to local shunts of photovoltaic cell, and (ii thin-film heterojunction of polypyrrole (PPy electropolymerized on hydrogen-terminated diamond, indicating covalent bonding and transfer of charge carriers from PPy to diamond.

  11. Natural evolution inspired design of light trapping structure in thin film organic solar cells

    Science.gov (United States)

    Wang, Chen; Yu, Shuangcheng; Chen, Wei; Sun, Cheng

    2013-09-01

    Light trapping has been developed to effectively enhance the efficiency of the thin film solar cell by extending the pathlength for light interacting with the active materials. Searching for optimal light trapping design requires a delicate balance among all the competing physical processes, including light refraction, reflection, and absorption. The existing design methods mainly depend on engineers' intuition to predefine the topology of the light-trapping structure. However, these methods are not capable of handling the topological variation in reaching the optimal design. In this work, a systematic approach based on Genetic Algorithm is introduced to design the scattering pattern for effective light trapping. Inspired by natural evolution, this method can gradually improve the performance of light trapping structure through iterative procedures, producing the most favorable structure with minimized reflection and substantial enhancement in light absorption. Both slot waveguide based solar cell and a more realistic organic solar with a scattering layer consisting of nano-scale patterned front layer is optimized to maximize absorption by strongly coupling incident sun light into the localized photonic modes supported by the multilayer system. Rigorous coupled wave analysis (RCWA) is implemented to evaluate the absorbance. The optimized slot waveguide cell achieves a broadband absorption efficiency of 48.1% and more than 3-fold increase over the Yablonovitch limit and the optimized realistic organic cell exhibits nearly 50% average absorbance over the solar spectrum with short circuit current density five times larger than the control case using planar ITO layer.

  12. Zr-based metal-organic frameworks: design, synthesis, structure, and applications.

    Science.gov (United States)

    Bai, Yan; Dou, Yibo; Xie, Lin-Hua; Rutledge, William; Li, Jian-Rong; Zhou, Hong-Cai

    2016-04-21

    Among the large family of metal-organic frameworks (MOFs), Zr-based MOFs, which exhibit rich structure types, outstanding stability, intriguing properties and functions, are foreseen as one of the most promising MOF materials for practical applications. Although this specific type of MOF is still in its early stage of development, significant progress has been made in recent years. Herein, advances in Zr-MOFs since 2008 are summarized and reviewed from three aspects: design and synthesis, structure, and applications. Four synthesis strategies implemented in building and/or modifying Zr-MOFs as well as their scale-up preparation under green and industrially feasible conditions are illustrated first. Zr-MOFs with various structural types are then classified and discussed in terms of different Zr-based secondary building units and organic ligands. Finally, applications of Zr-MOFs in catalysis, molecule adsorption and separation, drug delivery, and fluorescence sensing, and as porous carriers are highlighted. Such a review based on a specific type of MOF is expected to provide guidance for the in-depth investigation of MOFs towards practical applications.

  13. Structural and electronic properties of thin organic heterointerfaces SnPc/PTCDA/Ag(111)

    Energy Technology Data Exchange (ETDEWEB)

    Haeming, Mark; Sauer, Christoph; Greif, Michael; Schoell, Achim [Universitaet Wuerzburg, Experimentelle Physik VII, Wuerzburg (Germany); Reinert, Friedrich [Universitaet Wuerzburg, Experimentelle Physik VII, Wuerzburg (Germany); KIT, Gemeinschaftslabor fuer Nanoanalytik, Karlsruhe (Germany)

    2011-07-01

    Knowledge about the structural and electronic properties of organic heterointerfaces is of vital importance for electronic devices based on organic semiconductors. Yet information about these systems is still scarce due to difficulties in preparing well defined interfaces. With tin-phtalocyanine (SnPc) deposited on a Ag(111) surface precovered by perylene-tetracarboxylic acid dianhydride (PTCDA) we present a well suited model system to gain insight into such heterointerfaces. Photoelectron spectroscopy (XPS and UPS) as well as near edge X-ray absorption fine structure (NEXAFS) studies are applied in order to gain both structural and electronic information. Distinct features in core-level and valence spectra allow us to unambiguously distinguish between both molecules. We show clear evidence that SnPc forms a flat lying wetting layer on top of PTCDA with a mainly physisorptive character. Moreover a rigid level shift of all spectroscopic SnPc features with respect to the homomolecular SnPc films is observed, similar to what is known for Schottky contacts, which corresponds to a change in work function. We demonstrate that the built-in electric field at the interface can be explained by the formation of an interface dipole, which extends over several adsorbate monolayers.

  14. Structure and applications of metal-organic framework based on cyanide and 3,5-dichloropyridine

    Science.gov (United States)

    Etaiw, Safaa El-din H.; El-bendary, Mohamed M.

    2013-06-01

    The reaction of the aqueous/acetonitrile solutions of K3[Cu(CN)4] and 3,5-dichloropyridine (3,5-dClpy), in the presence of Me3SnCl affords a new metal-organic framework (MOF), 3∞[(CuCN)2·(3,5-dClpy)2], 1. The structure of the MOF 1 was characterized by IR, UV-visible, TGA and X-ray single crystal analysis. The structure of MOF 1 consists of CuCN building blocks which are connected by CN group forming 1D-zig-zag chains. Each chain is bridged to another chain by hydrogen bonding organizing 2D-sheets. The structure of 1 is further close packed by hydrogen bonds, π-π stacking and lp-π interactions creating 3D-network. The emission spectra and the thermodynamic parameters from TGA of the MOF 1 were discussed. The MOF 1 was used as heterogeneous catalyst for the oxidative discoloration of methylene blue dye (MB) by dilute solution of hydrogen peroxide as oxidant. The in vitro cytotoxic activity has been evaluated against the human breast cancer cell lines MCF-7. The cytotoxic effect of the MOF 1 on the viability of MCF-7 cells was determined by MTT assay.

  15. Predicting total organic halide formation from drinking water chlorination using quantitative structure-property relationships.

    Science.gov (United States)

    Luilo, G B; Cabaniss, S E

    2011-10-01

    Chlorinating water which contains dissolved organic matter (DOM) produces disinfection byproducts, the majority of unknown structure. Hence, the total organic halide (TOX) measurement is used as a surrogate for toxic disinfection byproducts. This work derives a robust quantitative structure-property relationship (QSPR) for predicting the TOX formation potential of model compounds. Literature data for 49 compounds were used to train the QSPR in moles of chlorine per mole of compound (Cp) (mol-Cl/mol-Cp). The resulting QSPR has four descriptors, calibration [Formula: see text] of 0.72 and standard deviation of estimation of 0.43 mol-Cl/mol-Cp. Internal and external validation indicate that the QSPR has good predictive power and low bias (‰<‰1%). Applying this QSPR to predict TOX formation by DOM surrogates - tannic acid, two model fulvic acids and two agent-based model assemblages - gave a predicted TOX range of 136-184 µg-Cl/mg-C, consistent with experimental data for DOM, which ranged from 78 to 192 µg-Cl/mg-C. However, the limited structural variation in the training data may limit QSPR applicability; studies of more sulfur-containing compounds, heterocyclic compounds and high molecular weight compounds could lead to a more widely applicable QSPR.

  16. The brain imaging data structure, a format for organizing and describing outputs of neuroimaging experiments.

    Science.gov (United States)

    Gorgolewski, Krzysztof J; Auer, Tibor; Calhoun, Vince D; Craddock, R Cameron; Das, Samir; Duff, Eugene P; Flandin, Guillaume; Ghosh, Satrajit S; Glatard, Tristan; Halchenko, Yaroslav O; Handwerker, Daniel A; Hanke, Michael; Keator, David; Li, Xiangrui; Michael, Zachary; Maumet, Camille; Nichols, B Nolan; Nichols, Thomas E; Pellman, John; Poline, Jean-Baptiste; Rokem, Ariel; Schaefer, Gunnar; Sochat, Vanessa; Triplett, William; Turner, Jessica A; Varoquaux, Gaël; Poldrack, Russell A

    2016-01-01

    The development of magnetic resonance imaging (MRI) techniques has defined modern neuroimaging. Since its inception, tens of thousands of studies using techniques such as functional MRI and diffusion weighted imaging have allowed for the non-invasive study of the brain. Despite the fact that MRI is routinely used to obtain data for neuroscience research, there has been no widely adopted standard for organizing and describing the data collected in an imaging experiment. This renders sharing and reusing data (within or between labs) difficult if not impossible and unnecessarily complicates the application of automatic pipelines and quality assurance protocols. To solve this problem, we have developed the Brain Imaging Data Structure (BIDS), a standard for organizing and describing MRI datasets. The BIDS standard uses file formats compatible with existing software, unifies the majority of practices already common in the field, and captures the metadata necessary for most common data processing operations. PMID:27326542

  17. Materials for organic photovoltaics: insights from detailed structural models and molecular simulations

    Directory of Open Access Journals (Sweden)

    Po Riccardo

    2012-10-01

    Full Text Available This paper contains a brief discussion of the role of detailed structural and computational studies, within the general field of organic photovoltaics. We review some of our recent work on poly(3-butylthiophene (P3BT and on [6,6]phenyl-C61-butyric acid methyl ester (PCBM. The first is a prototypical hole-transporting material, whose crystal forms I.’ and II were solved by us through the combined use of powder Xray diffraction, electron diffraction and molecular modelling. PCBM is a widely used fullerene derivative with electron-transporting properties. It has a rich polymorphism, which to date remains largely unexplored. Our molecular dynamics simulations have revealed interesting features of its solid-state organization, including that in the amorphous phase.

  18. Probing the bonding and structures of metal-organic radicals with zero energy electrons

    Institute of Scientific and Technical Information of China (English)

    YANG DongSheng

    2012-01-01

    Metal-organic radicals are reactive and transient because of the existence of unpaired valence electrons,and thus the characterization of these open-shell systems is challenging.In our work,the radicals are synthesized by the reaction of bare metal atoms and organic ligands in a laser-vaporization supersonic molecular beam source and characterized with pulsed-field ionization zero electron kinetic energy (ZEKE) spectroscopy.The molecular beam ZEKE technique routinely yields sub-meV spectral resolution and is a powerful means to study the molecular bonding and structures.This account presents several examples of single-photon ZEKE spectroscopic applications in determining metal binding modes and molecular conformations.

  19. Molecular Dynamics of Structural Organization in Binary Fluids with Fixed Particles

    Institute of Scientific and Technical Information of China (English)

    唐彦立; 马余强

    2002-01-01

    We have numerically studied the structural organization in binary immiscible fluids with fixed particles. The particles that have a finite excluded volume and a selective affinity for one fluid component have a significant influence on the organization process, where the hydrodynamic flows induced by the interface motion are suppressed and the domain growth is slowed down at late stages. Two different cases with weak and strong preferential interactions are considered, and the results show that the particles in the former can be left in the unfavourable phase during the process but are permanently surrounded by the favourable phase in the latter. The study indicates that the system would develop into a dynamical steady state and the final domain size might be dependent not only on the number of particles but also on the preferential interaction strength.

  20. Distribution of transformed organic matter in structural units of loamy sandy soddy-podzolic soil

    Science.gov (United States)

    Kogut, B. M.; Yashin, M. A.; Semenov, V. M.; Avdeeva, T. N.; Markina, L. G.; Lukin, S. M.; Tarasov, S. I.

    2016-01-01

    The effect of land use types and fertilizing systems on the structural and aggregate composition of loamy sandy soddy-podzolic soil and the quantitative parameters of soil organic matter has been studied. The contribution of soil aggregates 2-1 mm in size to the total Corg reserve in the humus horizon is higher than the contributions of other aggregates by 1.3-4.2 times. Reliable correlations have been revealed between the contents of total (Corg), labile (Clab), and active (C0) organic matter in the soil. The proportion of C0 is 44-70% of Clab extractable by neutral sodium pyrophosphate solution. The contributions of each of the 2-1, 0.5-0.25, and humus horizon of loamy sandy soddy-podzolic soil, the active, slow, and passive pools contain 6-11, 34-65, and 26-94% of the total Corg, respectively.

  1. Lead and zinc in the structure of organic and mineral soil components

    Directory of Open Access Journals (Sweden)

    Larissa Kummer

    2013-04-01

    Full Text Available In addition to the more reactive forms, metals can occur in the structure of minerals, and the sum of all these forms defines their total contents in different soil fractions. The isomorphic substitution of heavy metals for example alters the dimensions of the unit cell and mineral size. This study proposed a method of chemical fractionation of heavy metals, using more powerful extraction methods, to remove the organic and different mineral phases completely. Soil samples were taken from eight soil profiles (0-10, 10-20 and 20-40 cm in a Pb mining and metallurgy area in Adrianópolis, Paraná, Brazil. The Pb and Zn concentrations were determined in the following fractions (complete phase removal in each sequential extraction: exchangeable; carbonates; organic matter; amorphous and crystalline Fe oxides; Al oxide, amorphous aluminosilicates and kaolinite; and residual fractions. The complete removal of organic matter and mineral phases in sequential extractions resulted in low participation of residual forms of Pb and Zn in the total concentrations of these metals in the soils: there was lower association of metals with primary and 2:1 minerals and refractory oxides. The powerful methods used here allow an identification of the complete metal-mineral associations, such as the occurrence of Pb and Zn in the structure of the minerals. The higher incidence of Zn than Pb in the structure of Fe oxides, due to isomorphic substitution, was attributed to a smaller difference between the ionic radius of Zn2+ and Fe3+.

  2. Core structures of haemosiderins deposited in various organs in β-thalassaemia/haemoglobin E disease

    International Nuclear Information System (INIS)

    Moessbauer spectra were recorded of tissue from β-thalassaemia/haemoglobin E spleen, liver, pancreas and heart and of crude haemosiderins (insoluble iron fraction) isolated from the organs. Iron in the crude haemosiderins from the spleen and heart remains paramagnetic below 4.2K indicating that the iron is in a non-crystalline form. Superparamagnetic behaviour of the crude haemosiderins from the pancreas and liver indicate the presence of ferrihydrite cores with some cores with a structure based on defect-goethite. (orig.)

  3. Core structures of haemosiderins deposited in various organs in β-thalassaemia/haemoglobin e disease

    Science.gov (United States)

    St. Pierre, T. G.; Tran, K. C.; Webb, J.; Macey, D. J.; Pootrakul, P.; Dickson, D. P. E.

    1992-04-01

    Mössbauer spectra were recorded of tissue from β-thalassaemia/haemoglobin E spleen, liver, pancreas and heart and of crude haemosiderins (insoluble iron fractions) isolated from the organs. Iron in the crude haemosiderins from the spleen and heart remains paramagnetic below 4.2K indicating that the iron is in a non-crystalline form. Superparamagnetic behaviour of the crude haemosiderins from the pancreas and liver indicate the presence of ferrihydrite cores with some cores with a structure based on defect-goethite.

  4. Leadership and leadership communication in a matrix structured organization : some critical factors

    OpenAIRE

    Røsdal, Trude

    2005-01-01

    This case study has shown how nearly every success and failure in the matrix structured Segment X was a result of leadership behaviour. If Project I was to be an unreserved success every leader on every level had to succeed in their efforts. After having interviewed employees and leaders, and observed several meetings the overall impression was of a well-functioning, mature matrix organization. However, it is not correct to say that Project I was an unreserved success. There were some areas w...

  5. Studies of the structure and properties of organic monolayers, multilayers and superlattices

    International Nuclear Information System (INIS)

    Organic monolayers and multilayers are both scientifically fascinating and technologically promising; they are, however, both complex systems and relatively inaccessible to experimental probes. In this progress report, we describe our x-ray diffraction studies, which have given us substantial new information about the structures and phase transitions in monolayers on the surface of water; our use of these monolayers as a unique probe of the dynamics of wetting and spreading; and our studies of monolayer mechanical properties using a simple but effective technique available to anyone using the Wilhelmy method to measure surface tension. 20 refs., 11 figs

  6. Studies on synthesis, growth, structural, optical properties of organic 8-hydroxyquinolinium succinate single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Thirumurugan, R., E-mail: singlecrystalxrd@gmail.com; Anitha, K., E-mail: singlecrystalxrd@gmail.com [School of Physics, Madurai Kamaraj University, Madurai-625021 (India)

    2014-04-24

    8-hydroxyquinolinium succinate (8HQSU), an organic material has been synthesized and single crystals were grown by employing the technique of slow evaporation. The structure of the grown crystal was elucidated by using single crystal X-ray diffraction analysis. 8HQSU crystal belongs to the monoclinic crystallographic system with non-centro symmetric space group of P2{sub 1}. FT-IR spectral investigation has been carried out to identify the various functional groups present in the grown crystal. UV–vis spectral studies reveal that 8HQSU crystals are transparent in the entire visible region and the cut-off wavelength has been found to be 220nm.

  7. Amplified spontaneous emission in an organic semiconductor multilayer waveguide structure including a highly conductive transparent electrode

    Science.gov (United States)

    Reufer, M.; Feldmann, J.; Rudati, P.; Ruhl, A.; Müller, D.; Meerholz, K.; Karnutsch, C.; Gerken, M.; Lemmer, U.

    2005-05-01

    We demonstrate that the amplified spontaneous emission (ASE) threshold in multilayer waveguide structures suitable for the use in future organic injection lasers can be drastically reduced by inserting a crosslinked hole transport layer (HTL) between a highly conductive indium tin oxide (ITO) electrode and the polymer emission layer. While no ASE is observed when the active layer material is directly spincoated onto the ITO electrode, it can be completely restored upon insertion of a 300-nm-thick HTL. This observation is attributed to reduced attenuation of the waveguided mode enabling the ASE process and is theoretically confirmed by calculations of the mode intensity fraction propagating in the absorptive ITO electrode.

  8. Defect-driven interfacial electronic structures at an organic/metal-oxide semiconductor heterojunction.

    Science.gov (United States)

    Winget, Paul; Schirra, Laura K; Cornil, David; Li, Hong; Coropceanu, Veaceslav; Ndione, Paul F; Sigdel, Ajaya K; Ginley, David S; Berry, Joseph J; Shim, Jaewon; Kim, Hyungchui; Kippelen, Bernard; Brédas, Jean-Luc; Monti, Oliver L A

    2014-07-16

    The electronic structure of the hybrid interface between ZnO and the prototypical organic semiconductor PTCDI is investigated via a combination of ultraviolet and X-ray photoelectron spectroscopy (UPS/XPS) and density functional theory (DFT) calculations. The interfacial electronic interactions lead to a large interface dipole due to substantial charge transfer from ZnO to 3,4,9,10-perylenetetracarboxylicdiimide (PTCDI), which can be properly described only when accounting for surface defects that confer ZnO its n-type properties. PMID:24830796

  9. Structure-Property Relations in Polymer:Fullerene Blends for Organic Solar Cells.

    Science.gov (United States)

    Banerji, Natalie

    2016-01-01

    Organic solar cells consist of thin films combining an electron donor (often a conjugated polymer) with an electron acceptor (often a fullerene derivative), in a blend commonly referred to as bulk heterojunction material. Charge separation between the donor and the acceptor leads to the generation of carriers, which can be extracted from photovoltaic devices in the form of photocurrent. The generation mechanism of free, extractable charges has caused a lot of controversial discussion in literature. Our research has shown that all the steps involved in charge generation are strongly dependent on the arrangement of the donor and the acceptor (i.e. the structure) of the bulk heterojunction. PMID:27561613

  10. A novel series of isoreticular metal organic frameworks: realizing metastable structures by liquid phase epitaxy

    OpenAIRE

    Liu, Jinxuan; Lukose, Binit; Shekhah, Osama; Arslan, Hasan Kemal; Weidler, Peter; Gliemann, Hartmut; Bräse, Stefan; Grosjean, Sylvain; Godt, Adelheid; Feng, Xinliang; Müllen, Klaus; Magdau, Ioan-Bogdan; Heine, Thomas; Wöll, Christof

    2012-01-01

    A novel class of metal organic frameworks (MOFs) has been synthesized from Cu-acetate and dicarboxylic acids using liquid phase epitaxy. The SURMOF-2 isoreticular series exhibits P4 symmetry, for the longest linker a channel-size of 3 × 3 nm2 is obtained, one of the largest values reported for any MOF so far. High quality, ab-initio electronic structure calculations confirm the stability of a regular packing of (Cu++)2- carboxylate paddle-wheel planes with P4 symmetry and reveal, that the SUR...

  11. Effect of Molecular Structure on Stability of Organic Nanoparticles Formed by Bodipy Dimers.

    Science.gov (United States)

    Lin, Wenhai; Zhang, Wei; Sun, Tingting; Gu, Jingkai; Xie, Zhigang; Jing, Xiabin

    2016-09-20

    The objective was to evaluate the stability of organic nanoparticles made from Bodipy dimers. Bodipy dimers with different length of linkers were synthesized via multicomponent Passerini reaction, and could form the fluorescent nanoparticles (FNPs) through nanoprecipitation. Bodipy-dimers FNPs with long chain linker indicated better stability in biological condition than those with short one as revealed by changes of diameter and size distribution. The FNPs possessed high physical homogeneity and low cytotoxicity. The molecular structure dependent stability was also validated by confocal laser scanning microscope based on the dissociation-induced fluorescence recovering. Importantly, stable FNPs also could be used to load hydrophobic cargoes and deliver them into cytoplasm. We believe this systematic study between structure and stability might open new opportunities for designing stable nanoparticles for various applications. PMID:27571251

  12. Structure-directing role of graphene in the synthesis of metal-organic framework nanowire.

    Science.gov (United States)

    Jahan, Maryam; Bao, Qiaoliang; Yang, Jia-Xiang; Loh, Kian Ping

    2010-10-20

    Graphene can be decorated with functional groups on either side of its basal plane, giving rise to a bifunctional nanoscale building block that can undergo face-to-face assembly. We demonstrate that benzoic acid-functionalized graphene (BFG) can act as a structure-directing template in influencing the crystal growth of metal-organic framework (MOF). BFG is also incorporated into MOF as framework linker. Because of the high density of carboxylic groups on benzoic acid-functionalized graphene, an unusual MOF nanowire that grows in the [220] direction was synthesized. The diameter of the nanowire correlates closely with the lateral dimensions of the BFG. The intercalation of graphene in MOF imparts new electrical properties such as photoelectric transport in the otherwise insulating MOF. The results point to the possibility of using functionalized graphene to synthesize a wide range of structural motifs in MOF with adjustable metrics and properties.

  13. Synthesis and Crystal Structure of a Magnesium Metal-organic Framework

    Institute of Scientific and Technical Information of China (English)

    WU Zhao-Feng; FENG Mei-Ling; HU Bing; HUANG Xiao-Ying; ZHAO Yu-Bao

    2011-01-01

    A magnesium metal organic framework, [N-H2(CH3)2][-N(CH3)4][Mgs(bpdc)3(O2CH)6]· 3H2O (1, bpdcH2 = 4,4'-biphenyldicarboxylic acid), has been solvothermally synthesized and structurally characterized. 1 crystallizes in the trigonal system, space group R-3, with a = 11.3427(3), c = 41.5662(18) A, V = 4631.3(3) A^3, Z = 3 and the final R = 0.0457. Its structure features a pillared-layered three-dimensional network with 8.21 A cavities, in which cationic [NH2(CH3)2]^+ or [N(CH3)4]^+ and lattice water molecules are located. Thermal stability of the title compound has also been investigated.

  14. Synthesis, structure, and masnetic properties of two novel lanthanide-organic frameworks

    Institute of Scientific and Technical Information of China (English)

    LI XiuHua; FANG Ming; ZHAO Bin

    2009-01-01

    Two novel metal-organic frameworks,{[Eu(phen)(NDA)1.5(H2O)]}n ((1);NDA = 2,6-naphthalenedicarboxylate ions,phen=1,10-phenanthroline) and {[Gd(phen)(NDA)1.5].0.5H2NDA}n (2),have been synthesized under hydrothermal conditions.The structure analyses of 1 and 2 reveal that the two compounds belong to the triclinic system with space group P-1.Compound 1 features a 2D lattice structure while compound 2 displays a novel 3D architecture.The two frameworks were further characterized by elemental analyses,luminescent spectrua,and variable-temperature magnetic susceptibilities.The investigation of luminescent property reveals that 1 exhibits characteristic red emission of Eu2+.Magnetic investigation suggests that the ferromagnetic coupling exists between adjacent Gd3+ in compound 2.

  15. Synthesis, structure, and magnetic properties of two novel lanthanide-organic frameworks

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Two novel metal-organic frameworks, {[Eu(phen)(NDA)1.5(H2O)]}n ((1); NDA = 2,6-naphthalenedicarboxylate ions, phen = 1,10-phenanthroline) and {[Gd(phen)(NDA)1.5]·0.5H2NDA}n (2), have been synthesized under hydrothermal conditions. The structure analyses of 1 and 2 reveal that the two compounds belong to the triclinic system with space group P-1. Compound 1 features a 2D lattice structure while compound 2 displays a novel 3D architecture. The two frameworks were further characterized by elemental analyses, luminescent spectrua, and variable-temperature magnetic susceptibilities. The investigation of lumi-nescent property reveals that 1 exhibits characteristic red emission of Eu3+. Magnetic investigation suggests that the ferromagnetic coupling exists between adjacent Gd3+ in compound 2.

  16. Self-organizing biochemical cycle in dynamic feedback with soil structure

    Science.gov (United States)

    Vasilyeva, Nadezda; Vladimirov, Artem; Smirnov, Alexander; Matveev, Sergey; Tyrtyshnikov, Evgeniy; Yudina, Anna; Milanovskiy, Evgeniy; Shein, Evgeniy

    2016-04-01

    In the present study we perform bifurcation analysis of a physically-based mathematical model of self-organized structures in soil (Vasilyeva et al., 2015). The state variables in this model included microbial biomass, two organic matter types, oxygen, carbon dioxide, water content and capillary pore size. According to our previous experimental studies, organic matter affinity to water is an important property affecting soil structure. Therefore, organic matter wettability was taken as principle distinction between organic matter types in this model. It considers general known biological feedbacks with soil physical properties formulated as a system of parabolic type non-linear partial differential equations with elements of discrete modeling for water and pore formation. The model shows complex behavior, involving emergence of temporal and spatial irregular auto-oscillations from initially homogeneous distributions. The energy of external impact on a system was defined by a constant oxygen level on the boundary. Non-linear as opposed to linear oxygen diffusion gives possibility of modeling anaerobic micro-zones formation (organic matter conservation mechanism). For the current study we also introduced population competition of three different types of microorganisms according to their mobility/feeding (diffusive, moving and fungal growth). The strongly non-linear system was solved and parameterized by time-optimized algorithm combining explicit and implicit (matrix form of Thomas algorithm) methods considering the time for execution of the evaluated time-step according to accuracy control. The integral flux of the CO2 state variable was used as a macroscopic parameter to describe system as a whole and validation was carried out on temperature series of moisture dependence for soil heterotrophic respiration data. Thus, soil heterotrophic respiration can be naturally modeled as an integral result of complex dynamics on microscale, arising from biological processes

  17. Understanding device-structure-induced variations in open-circuit voltage for organic photovoltaics.

    Science.gov (United States)

    Wang, Zhiping; Uemura, Yu; Zhou, Ying; Miyadera, Tetsuhiko; Azumi, Reiko; Yoshida, Yuji; Chikamatsu, Masayuki

    2015-05-27

    We investigate the structural influences on the device performance, especially on open-circuit voltage (V(OC)) in squaraine (SQ)/fullerene (C60) bilayer cells. Simply changing the SQ thickness could lead to 40% variation in V(OC) from 0.62 to 0.86 V. The ionization potential (IP) of SQ films and recombination at the anode surface as well as donor/acceptor (D/A) interface sensitively vary with film thicknesses, which account for the shifts in V(OC). The anode recombination can be effectively suppressed by preventing direct contact between C60 and the anode with a buffer layer, delivering an elevated V(OC). Through polarized infrared-multiple-angle incidence resolution spectroscopy measurement, the molecular structure of SQ films is found to gradually evolve from lying-down on indium-tin oxide substrates with noncentrosymmetric orientation at low thicknesses to random structure at high thicknesses. The different molecular orientation may yield different strengths of electronic coupling, which affects the charge-carrier recombination and thus V(OC). Moreover, the oriented SQ films would spontaneously compose aligned dipole moments at the D/A interface because of the strong dipolar effects in SQ molecules identified by density functional theory calculations, whereas no aligned interfacial dipole moment exists in the random structure. The resulting interfacial dipole moments would form an electric field at the D/A interface, leading to variations in the IP and thus impacting V(OC). Our findings demonstrate that V(OC) in organic photovoltaic cells is critically associated with the molecular orientation that affects the charge-carrier recombination and interfacial dipole alignment, which should be seriously taken into consideration for the design of organic molecules and optimization of the cell efficiency.

  18. Using operational and defined fractions to assess soil organic matter stabilization and structure

    Science.gov (United States)

    Horwath, W. R.

    2015-12-01

    Studies on soil organic matter (SOM) began with alkaline solvents revealing a dark colored substance that could be isolated under low pH. Further studies revealed fulvic and humic acids and humin fractions leading to theories on functional groups and metal-clay bridging mechanisms. The fate of isotopes in these fractions revealed soil carbon pools with varying turnover rates with half the soil carbon (C) in humin and acid hydrolyzed fractions over 1000 years old. These results are the basis of the three pool conceptual framework used in many biogeochemical models. Theories on the role of functional groups and compound classes further elaborated concepts on physical (aggregates) and chemical mechanisms of C stabilization. With the advance of analytical instrumentation, the operational fractions were further defined to the compound and molecular levels. These studies confirmed the majority of soil C is microbially derived. Our observation that all microbial groups contributed nonselectively to soil C maintenance independent of mineralogy suggests that compound characteristics within integrated structures are more important than the source of individual compounds for stabilizing soil C. In dissolved organic C floccing studies using Near Edge X-ray Fine Structure analysis, we found that aromatic compounds interacted first with Fe, however, the majority of direct bonds to Fe were polysaccharides, reinforcing that an integrative chemical structure rather than direct bonds imparted stability in organo-metal interactions. Using a novel differential scanning calorimeter coupled to an isotope ratio mass spectrometer setup, we confirmed that the presence of clays (independent of clay type) increased the microbial utilization of calcium stabilized high versus low temperature compounds, asserting that higher temperature compounds (i.e., phenolics) are likely less tightly bound by clay minerals. The integration of operational and defined fractions of SOM remains a legitimate

  19. Near-complete structural characterization of phosphatidylcholines using electron impact excitation of ions from organics.

    Science.gov (United States)

    Campbell, J Larry; Baba, Takashi

    2015-06-01

    Although lipids are critical components of many cellular assemblies and biological pathways, accurate descriptions of their molecular structures remain difficult to obtain. Many benchtop characterization methods require arduous and time-consuming procedures, and multiple assays are required whenever a new structural feature is probed. Here, we describe a new mass-spectrometry-based workflow for enhanced structural lipidomics that, in a single experiment, can yield almost complete structural information for a given glycerophospholipid (GPL) species. This includes the lipid's sum (Brutto) composition from the accurate mass measured for the intact lipid ion and the characteristic headgroup fragment, the regioisomer composition from fragment ions unique to the sn-1 and sn-2 positions, and the positions of carbon-carbon double bonds in the lipid acyl chains. Here, lipid ions are fragmented using electron impact excitation of ions from organics (EIEIO)--a technique where the singly charged lipid ions are irradiated by an electron beam, producing diagnostic product ions. We have evaluated this methodology on various lipid standards, as well as on a biological extract, to demonstrate this new method's utility.

  20. Analysis of the Molecules Structure and Vertical Electron Affinity of Organic Gas Impact on Electric Strength

    Science.gov (United States)

    Jiao, Juntao; Xiao, Dengming; Zhao, Xiaoling; Deng, Yunkun

    2016-05-01

    It is necessary to find an efficient selection method to pre-analyze the gas electric strength from the perspective of molecule structure and the properties for finding the alternative gases to sulphur hexafluoride (SF6). As the properties of gas are determined by the gas molecule structure, the research on the relationship between the gas molecule structure and the electric strength can contribute to the gas pre-screening and new gas development. In this paper, we calculated the vertical electron affinity, molecule orbits distribution and orbits energy of gas molecules by the means of density functional theory (DFT) for the typical structures of organic gases and compared their electric strengths. By this method, we find part of the key properties of the molecule which are related to the electric strength, including the vertical electron affinity, the lowest unoccupied molecule orbit (LUMO) energy, molecule orbits distribution and negative-ion system energy. We also listed some molecule groups such as unsaturated carbons double bonds (C=C) and carbonitrile bonds (C≡N) which have high electric strength theoretically by this method. supported by National Natural Science Foundation of China (Nos. 51177101 and 51337006)

  1. Roll-to-roll embedded conductive structures integrated into organic photovoltaic devices

    Science.gov (United States)

    van de Wiel, H. J.; Galagan, Y.; van Lammeren, T. J.; de Riet, J. F. J.; Gilot, J.; Nagelkerke, M. G. M.; Lelieveld, R. H. C. A. T.; Shanmugam, S.; Pagudala, A.; Hui, D.; Groen, W. A.

    2013-12-01

    Highly conductive screen printed metallic (silver) structures (current collecting grids) combined with poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) are a viable replacement for indium tin oxide (ITO) and inkjet printed silver as transparent electrode materials. To provide successful integration into organic photovoltaic (OPV) devices, screen printed silver current collecting grids should be embedded into a substrate to avoid topology issues. In this study micron-thick conductive structures are embedded and integrated into OPV devices. The embedded structures are produced roll-to-roll with optimized process settings and materials. Topology measurements show that the embedded grids are well suited for integration into OPV devices since the surface is almost without spikes and has low surface roughness. JV measurements of OPV devices with embedded structures on a polyethylene terephthalate/silicon nitride (PET/SiN) substrate show an efficiency of 2.15%, which is significantly higher than identical flexible devices with ITO (1.02%) and inkjet printed silver (1.48%). The use of embedded screen printed silver instead of ITO and inkjet printed silver in OPV devices will allow for higher efficiency devices which can be produced with larger design and process freedom.

  2. Roll-to-roll embedded conductive structures integrated into organic photovoltaic devices

    International Nuclear Information System (INIS)

    Highly conductive screen printed metallic (silver) structures (current collecting grids) combined with poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) are a viable replacement for indium tin oxide (ITO) and inkjet printed silver as transparent electrode materials. To provide successful integration into organic photovoltaic (OPV) devices, screen printed silver current collecting grids should be embedded into a substrate to avoid topology issues. In this study micron-thick conductive structures are embedded and integrated into OPV devices. The embedded structures are produced roll-to-roll with optimized process settings and materials. Topology measurements show that the embedded grids are well suited for integration into OPV devices since the surface is almost without spikes and has low surface roughness. JV measurements of OPV devices with embedded structures on a polyethylene terephthalate/silicon nitride (PET/SiN) substrate show an efficiency of 2.15%, which is significantly higher than identical flexible devices with ITO (1.02%) and inkjet printed silver (1.48%). The use of embedded screen printed silver instead of ITO and inkjet printed silver in OPV devices will allow for higher efficiency devices which can be produced with larger design and process freedom. (paper)

  3. Organizing for Competitiveness – Structural and Process Characteristics of Organizational Design

    Directory of Open Access Journals (Sweden)

    Tomislav Hernaus

    2013-12-01

    Full Text Available An emerging multidimensional approach to organizational design outlines the need for the alignment of relevant structural and process characteristics of organizations. However, neither the interaction of these characteristics nor their role and importance for organizational competitiveness is properly examined in the literature. Therefore, the main goal of this paper is to investigate the relationship between the structural and process characteristics of organizational design to determine how and to what extent these characteristics contribute to achieving a competitive advantage. The field survey was conducted on a cross-sectional sample of 134 Croatian companies. The research findings outlined the need for a new organizational design approach that emphasizes both the vertical and horizontal dimensions of design solutions. This paper contributes to previous research by showing that organizational design represents a source of competitive advantage only if structural and process characteristics are commonly designed. In addition, we confirmed that although structural characteristics are usually more often addressed, it is process characteristics that make a difference.

  4. Structure of the organic crystallite unit in coal as determined by X-ray diffraction

    Institute of Scientific and Technical Information of China (English)

    Song Dangyu; Yang Cunbei; Zhang Xiaokui; Su Xianbo; Zhang Xiaodong

    2011-01-01

    X-ray diffraction (XRD) was used to study the structure of the organic crystallite unit (La,Lc,d002) in coals collected from Henan and Shanxi Provinces,XRD patterns of coal were collected in a step-scan mode (0.1 °/step) over an angular range of 2-90° (2θ),allowing 8 s at each step.The structure of the crystallite unit was determined from the Scherrer equation and peak parameters deduced from whole pattern fitting.The results show that the structure of the crystallite unit in coal is mainly controlled by the coal rank.As the coal rank increases the average diameter of a coal crystallite unit (La) increases,the interlayer spacing (d002) decreases slightly,and the average height of a coal crystallite unit (Lc) increases at first but then decreases.A new diffraction peak from the crystallite unit in coal was found at a low scattering angle in the XRD pattern (2-10°).This suggests a structure with an inter-layer spacing from 1.9 to 2.8 nm exists in coal crystallites.

  5. Megacomplex organization of the oxidative phosphorylation system by structural analysis of respiratory supercomplexes from potato.

    Science.gov (United States)

    Bultema, Jelle B; Braun, Hans-Peter; Boekema, Egbert J; Kouril, Roman

    2009-01-01

    The individual protein complexes of the oxidative phosphorylation system (OXPHOS complexes I to V) specifically interact and form defined supramolecular structures, the so-called "respiratory supercomplexes". Some supercomplexes appear to associate into larger structures, or megacomplexes, such as a string of dimeric ATP synthase (complex V(2)). A row-like organization of OXPHOS complexes I, III and IV into respiratory strings has also been proposed. These transient strings cannot be purified after detergent solubilization. Hence the shape and composition of the respiratory string was approached by an extensive structural characterization of all its possible building blocks, which are the supercomplexes. About 400,000 molecular projections of supercomplexes from potato mitochondria were processed by single particle electron microscopy. We obtained two-dimensional projection maps of at least five different supercomplexes, including the supercomplex I+III(2), III(2)+IV(1), V(2), I+III(2)+IV(1) and I(2)+III(2) in different types of position. From these maps the relative position of the individual complexes in the largest unit, the I(2)+III(2)+IV(2) supercomplex, could be determined in a coherent way. The maps also show that the I+III(2)+IV(1) supercomplex, or respirasome, differs from its counterpart in bovine mitochondria. The new structural features allow us to propose a consistent model of the respiratory string, composed of repeating I(2)+III(2)+IV(2) units, which is in agreement with dimensions observed in former freeze-fracture electron microscopy data.

  6. Analysis of the Molecules Structure and Vertical Electron Affinity of Organic Gas Impact on Electric Strength

    Institute of Scientific and Technical Information of China (English)

    JIAO Juntao; XIAO Dengming; ZHAO Xiaoling; DENG Yunkun

    2016-01-01

    It is necessary to find an efficient selection method to pre-analyze the gas electric strength from the perspective of molecule structure and the properties for finding the alternative gases to sulphur hexafluoride (SF6).As the properties of gas are determined by the gas molecule structure,the research on the relationship between the gas molecule structure and the electric strength can contribute to the gas pre-screening and new gas development.In this paper,we calculated the vertical electron affinity,molecule orbits distribution and orbits energy of gas molecules by the means of density functional theory (DFT) for the typical structures of organic gases and compared their electric strengths.By this method,we find part of the key properties of the molecule which are related to the electric strength,including the vertical electron affinity,the lowest unoccupied molecule orbit (LUMO) energy,molecule orbits distribution and negativeion system energy.We also listed some molecule groups such as unsaturated carbons double bonds (C=C) and carbonitrile bonds (C≡N) which have high electric strength theoretically by this method.

  7. Structure and composition of organic reefs and carbonate mud mounds: concepts and categories

    Science.gov (United States)

    Riding, Robert

    2002-07-01

    Defined here as 'essentially in place calcareous deposits created by sessile organisms', Organic Reefs are diverse and complex structures with a long geological history. Their classification has been the subject of fierce debate, often characterized by reliance on subjective features such as wave-resistance and qualitative attempts to discriminate between 'first' and 'second class' reefs. In contrast, emphasis is here placed on the objective characteristic of the type of sedimentary support, which largely determines the sedimentary composition of the deposit. Constructional and depositional processes result in three principal sedimentary components: matrix (M), essentially in place skeletons (S) and cavity/ cement (C), whose proportions can be represented on MSC triangular plots. Separately or together, these components also provide the structural support for the reef. On these compositional and structural bases, three main categories of Organic Reef are recognized: Matrix-supported reefs (Agglutinated Microbial Reefs, Cluster Reefs, Segment Reefs), Skeleton-supported reefs (Frame Reefs), Cement-supported reefs (Cement Reefs). Agglutinated Microbial Reefs: possess laminated, clotted, or aphanitic fabrics created by microbial trapping of particulate sediment; in place skeletons and large primary cavities are rare; early cementation may provide added support; topographic relief is limited by the need for currents to provide sediment to accreting surfaces. Cluster Reefs: skeletal reefs in which essentially in place skeletons are adjacent, but not in contact, resulting in matrix support; characterized by relatively high matrix/skeleton ratios and low volumes of extra-skeletal early cement. Sediment trapping is an important corollary of skeletal growth and Cluster Reef organisms are tolerant of loose sediment. Absence of framework limits the topographic relief that Cluster Reefs can attain relative to spatial extent, and may permit bedding to develop within the reef

  8. New double graded structure for enhanced performance in white organic light emitting diode

    Energy Technology Data Exchange (ETDEWEB)

    Peng Yu Chen [Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung, 80424 Taiwan (China); Herng Yih Ueng, E-mail: hueng@ee.nsysu.edu.t [Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung, 80424 Taiwan (China); Yokoyama, Meiso [Department of Electronic Engineering, I-Shou University, Kaohsiung County, Taiwan (China)

    2010-10-15

    This study presents a new design that uses a combination of a graded hole transport layer (GH) structure and a gradually doped emissive layer (GE) structure as a double graded (DG) structure to improve the electrical and optical performance of white organic light-emitting diodes (WOLEDs). The proposed structure is ITO/m-MTDATA (15 nm)/NPB (15 nm)/NPB: 25% BAlq (15 nm)/NPB: 50% BAlq (15 nm)/BAlq: 0.5% Rubrene (10 nm)/BAlq: 1% Rubrene (10 nm)/BAlq: 1.5% Rubrene (10 nm)/Alq{sub 3} (20 nm)/LiF (0.5 nm)/Al (200 nm). (m-MTDATA: 4,4',4'' -tris(3-methylphenylphenylamino)triphenylamine; NPB: N,N'-diphenyl-N,N'-bis(1-naphthyl-phenyl)-(1,1'-biphenyl)-4,4'-diamine; BAlq: aluminum (III) bis(2-methyl-8-quinolinato) 4-phenylphenolate; Rubrene: 5,6,11,12-tetraphenylnaphthacene; Alq{sub 3}: tris-(8-hydroxyquinoline) aluminum). By using this structure, the best performance of the WOLED is obtained at a luminous efficiency at 11.8 cd/A and the turn-on voltage of 100 cd/m{sup 2} at 4.6 V. The DG structure can eliminate the discrete interface, and degrade surplus holes, the electron-hole pairs are efficiently injected and balanced recombination in the emissive layer, thus the spectra are unchanged under various drive currents and quenching effects can be significantly suppressed. Those advantages can enhance efficiency and are immune to drive current density variations.

  9. Influence of organic modification on the structure and properties of polyurethane/sepiolite nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Chen Hongxiang, E-mail: chenhx_916@hotmail.com [Hubei Key Laboratory of Coal Conversion and New Carbon Material, College of Chemical Engineering and Technology, Wuhan University of Science and Technology, 947 Heping Road, 430081 Wuhan, Hubei (China); Zeng Danlin [Hubei Key Laboratory of Coal Conversion and New Carbon Material, College of Chemical Engineering and Technology, Wuhan University of Science and Technology, 947 Heping Road, 430081 Wuhan, Hubei (China); Xiao Xiaoqin [College of Machinery and Automation, Wuhan University of Science and Technology, 430081 Wuhan (China); Zheng Maosheng [Institute of Condensed Physics and Materials, Northwest University, 710069 Xi' an (China); Ke Changmei; Li Yanjun [Hubei Key Laboratory of Coal Conversion and New Carbon Material, College of Chemical Engineering and Technology, Wuhan University of Science and Technology, 947 Heping Road, 430081 Wuhan, Hubei (China)

    2011-01-25

    Research highlights: {yields} KH550 was the best among the three organic modifiers by comparing tensile properties, water resistance and swelling rate. {yields} FTIR revealed the strong interaction between KH550-Sp and the PU matrix. {yields} TEM revealed the compatibility of KH550-Sp and PU was improved. {yields} SEM confirmed the good dispersion of KH550-Sp in PU matrix. - Abstract: The polyurethane (PU) nanocomposites were prepared using organomodified sepiolite (organo-Sp) by in situ polymerization method. The clay was modified with three different organic modifiers such as {gamma}-aminopropyltriethoxylsilane (KH550), hexadecyltrimethylammonium bromide (CTAB) and lauric acid (LA). The morphology and the dispersion of organo-Sp in polyurethane were characterized by scanning electron microscope, transmission electron microscope and Fourier transform infrared spectroscopy. The influence of organo-Sp on the tensile properties, water resistance and swelling rate of polyurethane composites was studied. The results showed the properties and structure of polyurethane nanocomposites were related to the kind of organic modifier.

  10. Molecular structures of five adducts assembled from p-dimethylaminobenzaldehyde and organic acids

    Science.gov (United States)

    Jin, Shouwen; Wang, Lanqing; Liu, Hui; Liu, Li; Zhang, Huan; Wang, Daqi; Li, Minghui; Guo, Jianzhong; Guo, Ming

    2016-07-01

    Five adducts 1-5 derived from p-dimethylaminobenzaldehyde have been prepared and characterized by X-ray diffraction analysis, IR, mp, and elemental analysis. Of the five adducts two are organic salts (1, and 2) and the other three (3-5) are cocrystals. In salts 1, and 2, the L molecules are protonated. The supramolecular architectures of the adducts 1-5 involve extensive intermolecular N-H⋯O, O-H⋯O, O-H⋯S, and C-H⋯O hydrogen bonds as well as other non-covalent interactions. The role of weak and strong non-covalent interactions in the crystal packing is ascertained. The complexes displayed 2D/3D framework structure for the synergistic effect of the various non-covalent interactions. The results presented herein tell that the strength and directionality of the N-H⋯O, O-H⋯O, and O-H⋯S hydrogen bonds between organic acids and p-dimethylaminobenzaldehyde are sufficient to bring about the formation of binary cocrystals or organic salts.

  11. Influence of organic modification on the structure and properties of polyurethane/sepiolite nanocomposites

    International Nuclear Information System (INIS)

    Research highlights: → KH550 was the best among the three organic modifiers by comparing tensile properties, water resistance and swelling rate. → FTIR revealed the strong interaction between KH550-Sp and the PU matrix. → TEM revealed the compatibility of KH550-Sp and PU was improved. → SEM confirmed the good dispersion of KH550-Sp in PU matrix. - Abstract: The polyurethane (PU) nanocomposites were prepared using organomodified sepiolite (organo-Sp) by in situ polymerization method. The clay was modified with three different organic modifiers such as γ-aminopropyltriethoxylsilane (KH550), hexadecyltrimethylammonium bromide (CTAB) and lauric acid (LA). The morphology and the dispersion of organo-Sp in polyurethane were characterized by scanning electron microscope, transmission electron microscope and Fourier transform infrared spectroscopy. The influence of organo-Sp on the tensile properties, water resistance and swelling rate of polyurethane composites was studied. The results showed the properties and structure of polyurethane nanocomposites were related to the kind of organic modifier.

  12. Recent Advances in Organic Photovoltaics: Device Structure and Optical Engineering Optimization on the Nanoscale.

    Science.gov (United States)

    Luo, Guoping; Ren, Xingang; Zhang, Su; Wu, Hongbin; Choy, Wallace C H; He, Zhicai; Cao, Yong

    2016-03-23

    Organic photovoltaic (OPV) devices, which can directly convert absorbed sunlight to electricity, are stacked thin films of tens to hundreds of nanometers. They have emerged as a promising candidate for affordable, clean, and renewable energy. In the past few years, a rapid increase has been seen in the power conversion efficiency of OPV devices toward 10% and above, through comprehensive optimizations via novel photoactive donor and acceptor materials, control of thin-film morphology on the nanoscale, device structure developments, and interfacial and optical engineering. The intrinsic problems of short exciton diffusion length and low carrier mobility in organic semiconductors creates a challenge for OPV designs for achieving optically thick and electrically thin device structures to achieve sufficient light absorption and efficient electron/hole extraction. Recent advances in the field of OPV devices are reviewed, with a focus on the progress in device architecture and optical engineering approaches that lead to improved electrical and optical characteristics in OPV devices. Successful strategies are highlighted for light wave distribution, modulation, and absorption promotion inside the active layer of OPV devices by incorporating periodic nanopatterns/nanostructures or incorporating metallic nanomaterials and nanostructures.

  13. Neutron reflectrometry reveals the internal structure of natural organic matter deposited onto an aluminum oxide

    Energy Technology Data Exchange (ETDEWEB)

    Mayes, Melanie [ORNL; Jagadamma, Sindhu [ORNL; Ambaye, Haile Arena [ORNL; Petridis, Loukas [ORNL; Lauter, Valeria [ORNL

    2013-01-01

    Organic carbon (OC) stabilization in soils plays a significant role in the global C cycle, therefore understanding the structure and function of the OC soil mineral interface is of high importance. To study the interface, films of simple OC compounds and natural organic matter (NOM) were deposited onto a soil mineral analogue (Al2O3) using spin coating and were exposed to humidity. The thickness, density and structure of the films were studied using a depth-sensitive, nano-scale technique of neutron reflectometry. A single homogenous layer was observed when NOM and glucose (GL) were adsorbed onto Al2O3. However, when stearic acid (SA) was added to either NOM or GL, separate layers attributed to SA and either NOM or GL were detected. The formation of distinct, immiscible layers is due to insolubility of SA with NOM and GL. In contrast, GL and NOM are both water-soluble, and therefore soluble with each other, forming a homogenous layer on the mineral surface. Our results suggest that the extent of complex layering formed on the OC mineral interface may depend on the relative solubility of the compounds.

  14. Interactions between radionuclides and organic colloids. Structure and reactivity of humic compounds

    International Nuclear Information System (INIS)

    Humic compounds are the main organic colloids present in natural waters. These compounds can significantly modify the speciation of metals and control their properties, like migration, toxicity or bio-availability. It is thus important to study their speciation in conditions representative to those encountered in the natural environment. The aim of this work is to analyze the reactivity of these humic compounds. Two spectroscopic techniques have been used: the time-resolution laser spectro-fluorimetry, limited to the study of fluorescent elements, and the electro-spray source mass spectroscopy which requires the development of specific protocols for all elements of the periodic classification system. Europium, a fluorescent element analogue to trivalent actinides, has been chosen as test-metal for the intercomparison of both spectroscopic techniques. The first technique has permitted to determine the inorganic and organic speciation (spectra and lifetime of europium hydroxides and carbonates, and constants of interaction with humic acids, respectively). The limitations of this technique in the study of inorganic speciation has been evidenced. Humic compounds have a badly defined structure. The use of high-resolution mass spectroscopy has permitted to propose in a direct and experimental way, a molecular structure of aquatic fulvic acids in agreement with their known physico-chemical properties. (J.S.)

  15. Structure Characterization and Properties of Metal-Surfactant Complexes Dispersed in Organic Solvents.

    Science.gov (United States)

    de la Iglesia, Pablo; Jaeger, Vance W; Xi, Yuyin; Pfaendtner, Jim; Pozzo, Lilo D

    2015-08-25

    This work describes the synthesis and characterization of metal-surfactant complexes. Dioctyl sulfosuccinate and dodecylbenzenesulfonate are associated with multivalent aluminum, iron, and vanadium ions using an ion exchange reaction. The metal complexes are dispersible in various organic solvents. In solvents with low polarity, the complexes form "inverse" macromolecular structures with multiple metal ions. In contrast, in alcohols, the complex size is reduced, showing a more disperse conformation. The metal and surfactant ions are still strongly bonded to each other in all the solvents probed. Small-angle X-ray and neutron scattering (SAXS and SANS) are used to characterize the structures. Simultaneous fitting of neutron and X-ray scattering spectra is performed in order to obtain an accurate description of the system. Scattering results are also validated by performing molecular dynamics (MD) simulations. The conductive and electrochemical properties of the complexes in solution are also evaluated. The dispersion of metal-organic complexes significantly increases electric conductivity, and some metal ions in the core of the complexes are shown to be electrochemically active in apolar solvents.

  16. Role of α-Helical Structure in Organic Solvent-Activated Homodimer of Elastase Strain K

    Directory of Open Access Journals (Sweden)

    Chee Fah Wong

    2011-09-01

    Full Text Available Recombinant elastase strain K overexpressed from E. coli KRX/pCon2(3 was purified to homogeneity by a combination of hydrophobic interaction chromatography and ion exchange chromatography, with a final yield of 48% and a 25-fold increase in specific activity. The purified protein had exhibited a first ever reported homodimer size of 65 kDa by SDS-PAGE and MALDI-TOF, a size which is totally distinct from that of typically reported 33 kDa monomer from P. aeruginosa. The organic solvent stability experiment had demonstrated a stability pattern which completely opposed the rules laid out in previous reports in which activity stability and enhancement were observed in hydrophilic organic solvents such as DMSO, methanol, ethanol and 1-propanol. The high stability and enhancement of the enzyme in hydrophilic solvents were explained from the view of alteration in secondary structures. Elastinolytic activation and stability were observed in 25 and 50% of methanol, respectively, despite slight reduction in α-helical structure caused upon the addition of the solvent. Further characterization experiments had postulated great stability and enhancement of elastase strain K in broad range of temperatures, pHs, metal ions, surfactants, denaturing agents and substrate specificity, indicating its potential application in detergent formulation.

  17. Recent Advances in Organic Photovoltaics: Device Structure and Optical Engineering Optimization on the Nanoscale.

    Science.gov (United States)

    Luo, Guoping; Ren, Xingang; Zhang, Su; Wu, Hongbin; Choy, Wallace C H; He, Zhicai; Cao, Yong

    2016-03-23

    Organic photovoltaic (OPV) devices, which can directly convert absorbed sunlight to electricity, are stacked thin films of tens to hundreds of nanometers. They have emerged as a promising candidate for affordable, clean, and renewable energy. In the past few years, a rapid increase has been seen in the power conversion efficiency of OPV devices toward 10% and above, through comprehensive optimizations via novel photoactive donor and acceptor materials, control of thin-film morphology on the nanoscale, device structure developments, and interfacial and optical engineering. The intrinsic problems of short exciton diffusion length and low carrier mobility in organic semiconductors creates a challenge for OPV designs for achieving optically thick and electrically thin device structures to achieve sufficient light absorption and efficient electron/hole extraction. Recent advances in the field of OPV devices are reviewed, with a focus on the progress in device architecture and optical engineering approaches that lead to improved electrical and optical characteristics in OPV devices. Successful strategies are highlighted for light wave distribution, modulation, and absorption promotion inside the active layer of OPV devices by incorporating periodic nanopatterns/nanostructures or incorporating metallic nanomaterials and nanostructures. PMID:26856789

  18. Structuralization of Ca(2+)-Based Metal-Organic Frameworks Prepared via Coordination Replication of Calcium Carbonate.

    Science.gov (United States)

    Sumida, Kenji; Hu, Ming; Furukawa, Shuhei; Kitagawa, Susumu

    2016-04-01

    The emergence of metal-organic frameworks (MOFs) as potential candidates to supplant existing adsorbent types in real-world applications has led to an explosive growth in the number of compounds available to researchers, as well as in the diversity of the metal salts and organic linkers from which they are derived. In this context, the use of carbonate-based precursors as metal sources is of interest due to their abundance in mineral deposits and their reaction chemistry with acids, resulting in just water and carbon dioxide as side products. Here, we have explored the use of calcium carbonate as a metal source and demonstrate its versatility as a precursor to several known frameworks, as well as a new flexible compound based on the 2,5-dihydroxybenzoquinone (H2dhbq) linker, Ca(dhbq)(H2O)2. Furthermore, inspired by the ubiquity and unique structures of biomineralized forms of calcium carbonate, we also present examples of the preparation of superstructures of Ca-based MOFs via the coordination replication technique. In all, the results confirm the suitability of carbonate-based metal sources for the preparation of MOFs and further expand upon the growing scope of coordination replication as a convenient strategy for the preparation of structuralized materials. PMID:27002690

  19. Report on the sixth blind test of organic crystal structure prediction methods.

    Science.gov (United States)

    Reilly, Anthony M; Cooper, Richard I; Adjiman, Claire S; Bhattacharya, Saswata; Boese, A Daniel; Brandenburg, Jan Gerit; Bygrave, Peter J; Bylsma, Rita; Campbell, Josh E; Car, Roberto; Case, David H; Chadha, Renu; Cole, Jason C; Cosburn, Katherine; Cuppen, Herma M; Curtis, Farren; Day, Graeme M; DiStasio, Robert A; Dzyabchenko, Alexander; van Eijck, Bouke P; Elking, Dennis M; van den Ende, Joost A; Facelli, Julio C; Ferraro, Marta B; Fusti-Molnar, Laszlo; Gatsiou, Christina Anna; Gee, Thomas S; de Gelder, René; Ghiringhelli, Luca M; Goto, Hitoshi; Grimme, Stefan; Guo, Rui; Hofmann, Detlef W M; Hoja, Johannes; Hylton, Rebecca K; Iuzzolino, Luca; Jankiewicz, Wojciech; de Jong, Daniël T; Kendrick, John; de Klerk, Niek J J; Ko, Hsin Yu; Kuleshova, Liudmila N; Li, Xiayue; Lohani, Sanjaya; Leusen, Frank J J; Lund, Albert M; Lv, Jian; Ma, Yanming; Marom, Noa; Masunov, Artëm E; McCabe, Patrick; McMahon, David P; Meekes, Hugo; Metz, Michael P; Misquitta, Alston J; Mohamed, Sharmarke; Monserrat, Bartomeu; Needs, Richard J; Neumann, Marcus A; Nyman, Jonas; Obata, Shigeaki; Oberhofer, Harald; Oganov, Artem R; Orendt, Anita M; Pagola, Gabriel I; Pantelides, Constantinos C; Pickard, Chris J; Podeszwa, Rafal; Price, Louise S; Price, Sarah L; Pulido, Angeles; Read, Murray G; Reuter, Karsten; Schneider, Elia; Schober, Christoph; Shields, Gregory P; Singh, Pawanpreet; Sugden, Isaac J; Szalewicz, Krzysztof; Taylor, Christopher R; Tkatchenko, Alexandre; Tuckerman, Mark E; Vacarro, Francesca; Vasileiadis, Manolis; Vazquez-Mayagoitia, Alvaro; Vogt, Leslie; Wang, Yanchao; Watson, Rona E; de Wijs, Gilles A; Yang, Jack; Zhu, Qiang; Groom, Colin R

    2016-08-01

    The sixth blind test of organic crystal structure prediction (CSP) methods has been held, with five target systems: a small nearly rigid molecule, a polymorphic former drug candidate, a chloride salt hydrate, a co-crystal and a bulky flexible molecule. This blind test has seen substantial growth in the number of participants, with the broad range of prediction methods giving a unique insight into the state of the art in the field. Significant progress has been seen in treating flexible molecules, usage of hierarchical approaches to ranking structures, the application of density-functional approximations, and the establishment of new workflows and `best practices' for performing CSP calculations. All of the targets, apart from a single potentially disordered Z' = 2 polymorph of the drug candidate, were predicted by at least one submission. Despite many remaining challenges, it is clear that CSP methods are becoming more applicable to a wider range of real systems, including salts, hydrates and larger flexible molecules. The results also highlight the potential for CSP calculations to complement and augment experimental studies of organic solid forms. PMID:27484368

  20. Simvastatin and artesunate impact the structural organization of adult Schistosoma mansoni in hypercholesterolemic mice.

    Science.gov (United States)

    Alencar, Alba Cristina Miranda de Barros; Santos, Thais da Silva; Neves, Renata Heisler; Lopes Torres, Eduardo José; Nogueira-Neto, José Firmino; Machado-Silva, José Roberto

    2016-08-01

    Experimental data have shown that simvastatin and artesunate possess activity against Schistosoma mansoni worms in mice fed standard chow. However, little is known regarding the roles of these drugs in mice fed high-fat chow. We have extended past studies by measuring the effects of these drugs on the structural organization of adult schistosomes in hypercholesterolemic mice. For this purpose, mice were gavaged with either simvastatin or artesunate at nine weeks post-infection and were euthanized by cervical dislocation at two weeks post-treatment. Adult worms were then collected and examined by conventional light microscopy, morphometry and confocal laser scanning microscopy. Plasma total cholesterol and worm reduction rates were significantly increased in mice fed high-fat chow compared with their respective control groups. Simvastatin and artesunate caused changes in the tegument, tubercles, and reproductive system (testicular lobes, vitelline glands and ovarian cells), particularly when administered to mice fed high-fat chow. In particular, the tegument and tubercles were significantly thinner in artesunate-treated worms in mice fed high-fat chow compared with mice fed standard chow. This study thus demonstrated that simvastatin and artesunate have several novel effects on the structural organization of adult worms. Together, these results show, for the first time, that simvastatin and artesunate display antischistosomal activity in hypercholesterolemic mice. PMID:27228897

  1. Report on the sixth blind test of organic crystal structure prediction methods.

    Science.gov (United States)

    Reilly, Anthony M; Cooper, Richard I; Adjiman, Claire S; Bhattacharya, Saswata; Boese, A Daniel; Brandenburg, Jan Gerit; Bygrave, Peter J; Bylsma, Rita; Campbell, Josh E; Car, Roberto; Case, David H; Chadha, Renu; Cole, Jason C; Cosburn, Katherine; Cuppen, Herma M; Curtis, Farren; Day, Graeme M; DiStasio, Robert A; Dzyabchenko, Alexander; van Eijck, Bouke P; Elking, Dennis M; van den Ende, Joost A; Facelli, Julio C; Ferraro, Marta B; Fusti-Molnar, Laszlo; Gatsiou, Christina Anna; Gee, Thomas S; de Gelder, René; Ghiringhelli, Luca M; Goto, Hitoshi; Grimme, Stefan; Guo, Rui; Hofmann, Detlef W M; Hoja, Johannes; Hylton, Rebecca K; Iuzzolino, Luca; Jankiewicz, Wojciech; de Jong, Daniël T; Kendrick, John; de Klerk, Niek J J; Ko, Hsin Yu; Kuleshova, Liudmila N; Li, Xiayue; Lohani, Sanjaya; Leusen, Frank J J; Lund, Albert M; Lv, Jian; Ma, Yanming; Marom, Noa; Masunov, Artëm E; McCabe, Patrick; McMahon, David P; Meekes, Hugo; Metz, Michael P; Misquitta, Alston J; Mohamed, Sharmarke; Monserrat, Bartomeu; Needs, Richard J; Neumann, Marcus A; Nyman, Jonas; Obata, Shigeaki; Oberhofer, Harald; Oganov, Artem R; Orendt, Anita M; Pagola, Gabriel I; Pantelides, Constantinos C; Pickard, Chris J; Podeszwa, Rafal; Price, Louise S; Price, Sarah L; Pulido, Angeles; Read, Murray G; Reuter, Karsten; Schneider, Elia; Schober, Christoph; Shields, Gregory P; Singh, Pawanpreet; Sugden, Isaac J; Szalewicz, Krzysztof; Taylor, Christopher R; Tkatchenko, Alexandre; Tuckerman, Mark E; Vacarro, Francesca; Vasileiadis, Manolis; Vazquez-Mayagoitia, Alvaro; Vogt, Leslie; Wang, Yanchao; Watson, Rona E; de Wijs, Gilles A; Yang, Jack; Zhu, Qiang; Groom, Colin R

    2016-08-01

    The sixth blind test of organic crystal structure prediction (CSP) methods has been held, with five target systems: a small nearly rigid molecule, a polymorphic former drug candidate, a chloride salt hydrate, a co-crystal and a bulky flexible molecule. This blind test has seen substantial growth in the number of participants, with the broad range of prediction methods giving a unique insight into the state of the art in the field. Significant progress has been seen in treating flexible molecules, usage of hierarchical approaches to ranking structures, the application of density-functional approximations, and the establishment of new workflows and `best practices' for performing CSP calculations. All of the targets, apart from a single potentially disordered Z' = 2 polymorph of the drug candidate, were predicted by at least one submission. Despite many remaining challenges, it is clear that CSP methods are becoming more applicable to a wider range of real systems, including salts, hydrates and larger flexible molecules. The results also highlight the potential for CSP calculations to complement and augment experimental studies of organic solid forms.

  2. Organic-inorganic semiconductor hybrid systems. Structure, morphology, and electronic properties

    Energy Technology Data Exchange (ETDEWEB)

    El Helou, Mira

    2012-08-22

    This dissertation addresses the preparation and characterization of hybrid semiconducting systems combining organic with inorganic materials. Characterization methods used included to determine the structure, morphology, and thermal stability comprised X-ray diffraction (XRD), atomic force microscopy (AFM), thermal desorption spectroscopy (TDS), and X-ray photoelectron spectroscopy (XPS). One organic-inorganic semiconducting system was pentacene (C{sub 22}H{sub 14}) and zinc oxide. This interface was investigated in detail for pentacene on an oxygen-terminated zinc oxide surface, i.e. ZnO(000 anti 1). An extended study on the promising p-n junction was carried out for pentacene on ZnO with different orientations which exhibit different chemical and structural characteristics: ZnO(000 anti 1), ZnO(0001), and ZnO(10 anti 10). Moreover, the organic crystal structure of pentacene was selectively tuned by carefully choosing the substrate temperature. This defined interface with a physisorbed pentacene layer on ZnO was characterized by optical absorption which depends on the temperature of the measured system, the pentacene film thickness, and the molecular orientation and packing. The high quality of the pentacene films allowed in one case to characterize the Davydov splitting by linear polarized light focused on a single crystallite. Another subject in the field of organic-inorganic hybrid materials comprised conjugated dithiols used as self-assembled monolayers (SAMs) for immobilizing semiconducting CdS nanoparticles (NPs) on Au substrates. It was demonstrated that an appropriate selection and preparation of the conjugated SAMs is crucial for building up a light-addressable potentiometric sensor with a sufficient efficiency. An optimized electron transfer was achieved with SAMs of long range ordering, high stability, and adequate conductivity. This was examined for different linkers and was best for stilbenedithiol immobilized in solution at higher temperatures. Due

  3. Conventionalisation of organic farming practices: from structural criteria towards an assessment based on organic principles. A review

    OpenAIRE

    Darnhofer, Ika; Lindenthal, Thomas; Bartel-Kratochvil, Ruth; Zollitsch, Werner

    2010-01-01

    International audience Organic farming is widely perceived as being more environmentally friendly than conventional farming. As a form of sustainable agriculture, it receives substantial support from policy for its contribution to environmental protection as well as the provision of amenities such as biodiversity and cultural landscapes. Consumers are attracted to organic foods as they are produced without synthetic chemicals and comply with higher animal welfare standards. Although organi...

  4. Evaluation of planning dose accuracy in case of radiation treatment on inhomogeneous organ structure

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chan Yong; Lee, Jae Hee; Kwak, Yong Kook; Ha, Min Yong [Dept. of Radiation Oncology, Seoul National University Hospital, Seoul (Korea, Republic of)

    2013-09-15

    We are to find out the difference of calculated dose of treatment planning system (TPS) and measured dose in case of inhomogeneous organ structure. Inhomogeneous phantom is made with solid water phantom and cork plate. CT image of inhomogeneous phantom is acquired. Treatment plan is made with TPS (Pinnacle3 9.2. Royal Philips Electronics, Netherlands) and calculated dose of point of interest is acquired. Treatment plan was delivered in the inhomogeneous phantom by ARTISTE (Siemens AG, Germany) measured dose of each point of interest is obtained with Gafchromic EBT2 film (International Specialty Products, US) in the gap between solid water phantom or cork plate. To simulate lung cancer radiation treatment, artificial tumor target of paraffin is inserted in the cork volume of inhomogeneous phantom. Calculated dose and measured dose are acquired as above. In case of inhomogeneous phantom experiment, dose difference of calculated dose and measured dose is about -8.5% at solid water phantom-cork gap and about -7% lower in measured dose at cork-solid water phantom gap. In case of inhomogeneous phantom inserted paraffin target experiment, dose difference is about 5% lower in measured dose at cork-paraffin gap. There is no significant difference at same material gap in both experiments. Radiation dose at the gap between two organs with different electron density is significantly lower than calculated dose with TPS. Therefore, we must be aware of dose calculation error in TPS and great care is suggested in case of radiation treatment planning on inhomogeneous organ structure.

  5. Exact matrix treatment of an osmotic ensemble model of adsorption and pressure induced structural transitions in metal organic frameworks.

    Science.gov (United States)

    Dunne, Lawrence J; Manos, George

    2016-03-14

    Here we present an exactly treated quasi-one dimensional statistical mechanical osmotic ensemble model of pressure and adsorption induced breathing structural transformations of metal-organic frameworks (MOFs). The treatment uses a transfer matrix method. The model successfully reproduces the gas and pressure induced structural changes which are observed experimentally in MOFs. The model treatment presented here is a significant step towards analytical statistical mechanical treatments of flexible metal-organic frameworks.

  6. INTRODUCING THE ORGANIZING STRUCTURES OF MANAGEMENT WITH MARKETING ORIENTATION ON ENTERPRISE OF THE BRANCHES TO DIFFICULT INDUSTRY OF THE UKRAINE

    OpenAIRE

    Hussarov, O.; Antipceva, O.

    2010-01-01

    The article is devoted the theoretical and practical aspects of organization of marketing activity on an industrial enterprise. Authors are expose failings in the field of organization of marketing activity on the enterprises of industries of heavy industry and suggestions are developed on their liquidation by the gradual passing to the computer-integrated marketings structures.

  7. Factor Structure of the Primary Scales of the Inventory of Personality Organization in a Nonclinical Sample Using Exploratory Structural Equation Modeling

    Science.gov (United States)

    Ellison, William D.; Levy, Kenneth N.

    2012-01-01

    Using exploratory structural equation modeling and multiple regression, we examined the factor structure and criterion relations of the primary scales of the Inventory of Personality Organization (IPO; Kernberg & Clarkin, 1995) in a nonclinical sample. Participants (N = 1,260) completed the IPO and measures of self-concept clarity, defenses,…

  8. Explaining the Relationship between Organizational Structure and Dimensions of Learning Organizations (Case study: Education Organization in Boroojerd County and the Related Departments

    Directory of Open Access Journals (Sweden)

    Javad Mehrabi

    2013-04-01

    Full Text Available The present survey has been conducted to explain the relationship between organizational structure and dimensions of learning organizations. It was conducted using descriptive-field method. The statistical population included employees of Education Organization in Borujerd County and the related departments. Sample volume was selected through random sampling method and was equal to 140 persons using Morgan table. Validity of the questionnaire was confirmed through content validity by professors and the clear-sighted. Its reliability was measured using pre-test and calculating Cronbach alpha. Pierson correlation coefficient, Friedman test and bi-nominal test using SPSS software were used for data analysis. Results of Pierson correlation coefficient test show there is a significant and negative relationship between organizational structure and fulfillment degree of learning organizations. This relationship is significant about all dimensions of learning organization. Given to results of Friedman test, the most important dimension of learning organizations is the component of team learning based on the viewpoint of employees of the Education Organization. According to results of bi-nominal test, there is only one variable in the statistical population and that is mental models. Also according to results of correlation coefficient matrix of research variables team learning and shared vision have the highest correlation.

  9. 网络信息组织中超文本链接的优化%Optimization of Hyperlink Structure in Network Information Organization

    Institute of Scientific and Technical Information of China (English)

    黄晓斌

    2003-01-01

    The article analyzes the structures and types of Web page hyperlinks, describes their characteristics and functions, and discusses how to optimize hyperlink structure in network information organization.

  10. Scanning probe microscopy investigation of self-organized perylenetetracarboxdiimide nanostructures at surfaces: structural and electronic properties.

    Science.gov (United States)

    Palermo, Vincenzo; Liscio, Andrea; Gentilini, Desirée; Nolde, Fabian; Müllen, Klaus; Samorì, Paolo

    2007-01-01

    A scanning probe microscopy investigation of the self-organization and local electronic properties of spin-coated ultrathin films of N-alkyl substituted perylenetetracarboxdiimide (PDI) is described. By carefully balancing the interplay between molecule-molecule and molecule-substrate interactions, PDI is able to form highly ordered supramolecular architectures on flat surfaces from solution. On an electrically insulating yet highly polar surface (mica) PDI forms strongly anisotropic architectures with needlelike structures with lengths of up to a few micrometers. On a conductive yet apolar surface (highly oriented pyrolytic graphite), the competition between the strong molecule-substrate interactions and the intermolecular forces leads to the generation of more disordered structures. The local electronic properties of these architectures are studied by Kelvin probe force microscopy by estimating their surface potential (SP). Quantitative measurements of the SP are obtained by analyzing the experimentally estimated SP data with a computational model, which discriminates between the intrinsic SP and the effect of long-range tip-surface interactions. The SP of PDI aggregates depends on the structural order at the supramolecular level. Narrow needles of constant width reveal identical SPs independent of length. Wider needles with a polydisperse width distribution exhibit a greater SP.

  11. Seamless metal-clad fiber-reinforced organic matrix composite structures and process for their manufacture

    Science.gov (United States)

    Bluck, Raymond M. (Inventor); Bush, Harold G. (Inventor); Johnson, Robert R. (Inventor)

    1990-01-01

    A metallic outer sleeve is provided which is capable of enveloping a hollow metallic inner member having continuous reinforcing fibers attached to the distal end thereof. The inner member is then introduced into outer sleeve until inner member is completely enveloped by outer sleeve. A liquid matrix member is then injected into space between inner member and outer sleeve. A pressurized heat transfer medium is flowed through the inside of inner member, thereby forming a fiber reinforced matrix composite material. The wall thicknesses of both inner member and outer sleeve are then reduced to the appropriate size by chemical etching, to adjust the thermal expansion coefficient of the metal-clad composite structure to the desired value. thereby forming a fiber reinforced matrix composite material. The wall thicknesses of both inner member and outer sleeve are then reduced to the appropriate size by chemical etching, to adjust the thermal expansion coefficient of the metal-clad composite structure to the desired value. The novelty of this invention resides in the development of a efficient method of producing seamless metal clad fiber reinforced organic matrix composite structures.

  12. Altered topological organization of white matter structural networks in patients with neuromyelitis optica.

    Directory of Open Access Journals (Sweden)

    Yaou Liu

    Full Text Available OBJECTIVE: To investigate the topological alterations of the whole-brain white-matter (WM structural networks in patients with neuromyelitis optica (NMO. METHODS: The present study involved 26 NMO patients and 26 age- and sex-matched healthy controls. WM structural connectivity in each participant was imaged with diffusion-weighted MRI and represented in terms of a connectivity matrix using deterministic tractography method. Graph theory-based analyses were then performed for the characterization of brain network properties. A multiple linear regression analysis was performed on each network metric between the NMO and control groups. RESULTS: The NMO patients exhibited abnormal small-world network properties, as indicated by increased normalized characteristic path length, increased normalized clustering and increased small-worldness. Furthermore, largely similar hub distributions of the WM structural networks were observed between NMO patients and healthy controls. However, regional efficiency in several brain areas of NMO patients was significantly reduced, which were mainly distributed in the default-mode, sensorimotor and visual systems. Furthermore, we have observed increased regional efficiency in a few brain regions such as the orbital parts of the superior and middle frontal and fusiform gyri. CONCLUSION: Although the NMO patients in this study had no discernible white matter T2 lesions in the brain, we hypothesize that the disrupted topological organization of WM networks provides additional evidence for subtle, widespread cerebral WM pathology in NMO.

  13. Reversible Structural Swell-Shrink and Recoverable Optical Properties in Hybrid Inorganic-Organic Perovskite.

    Science.gov (United States)

    Zhang, Yupeng; Wang, Yusheng; Xu, Zai-Quan; Liu, Jingying; Song, Jingchao; Xue, Yunzhou; Wang, Ziyu; Zheng, Jialu; Jiang, Liangcong; Zheng, Changxi; Huang, Fuzhi; Sun, Baoquan; Cheng, Yi-Bing; Bao, Qiaoliang

    2016-07-26

    Ion migration in hybrid organic-inorganic perovskites has been suggested to be an important factor for many unusual behaviors in perovskite-based optoelectronics, such as current-voltage hysteresis, low-frequency giant dielectric response, and the switchable photovoltaic effect. However, the role played by ion migration in the photoelectric conversion process of perovskites is still unclear. In this work, we provide microscale insights into the influence of ion migration on the microstructure, stability, and light-matter interaction in perovskite micro/nanowires by using spatially resolved optical characterization techniques. We observed that ion migration, especially the migration of MA(+) ions, will induce a reversible structural swell-shrink in perovskites and recoverably affect the reflective index, quantum efficiency, light-harvesting, and photoelectric properties. The maximum ion migration quantity in perovskites was as high as approximately 30%, resulting in lattice swell or shrink of approximately 4.4%. Meanwhile, the evidence shows that ion migration in perovskites could gradually accelerate the aging of perovskites because of lattice distortion in the reversible structural swell-shrink process. Knowledge regarding reversible structural swell-shrink and recoverable optical properties may shed light on the development of optoelectronic and converse piezoelectric devices based on perovskites. PMID:27386731

  14. A novel series of isoreticular metal organic frameworks: realizing metastable structures by liquid phase epitaxy

    Science.gov (United States)

    Liu, Jinxuan; Lukose, Binit; Shekhah, Osama; Arslan, Hasan Kemal; Weidler, Peter; Gliemann, Hartmut; Bräse, Stefan; Grosjean, Sylvain; Godt, Adelheid; Feng, Xinliang; Müllen, Klaus; Magdau, Ioan-Bogdan; Heine, Thomas; Wöll, Christof

    2012-01-01

    A novel class of metal organic frameworks (MOFs) has been synthesized from Cu-acetate and dicarboxylic acids using liquid phase epitaxy. The SURMOF-2 isoreticular series exhibits P4 symmetry, for the longest linker a channel-size of 3 × 3 nm2 is obtained, one of the largest values reported for any MOF so far. High quality, ab-initio electronic structure calculations confirm the stability of a regular packing of (Cu++)2- carboxylate paddle-wheel planes with P4 symmetry and reveal, that the SURMOF-2 structures are in fact metastable, with a fairly large activation barrier for the transition to the bulk MOF-2 structures exhibiting a lower, twofold (P2 or C2) symmetry. The theoretical calculations also allow identifying the mechanism for the low-temperature epitaxial growth process and to explain, why a synthesis of this highly interesting, new class of high-symmetry, metastable MOFs is not possible using the conventional solvothermal process. PMID:23213357

  15. Seeking and Sharing Knowledge Using Social Media in an Organization: The Impact of Social Influence, Organization Structure and Social Capital

    Science.gov (United States)

    Schutz, Douglas M.

    2013-01-01

    The prolific use of social media tools such as blogs and wikis is leading several organizations to adopt these tools. However, success of social media depends on its use by employees to share and seek knowledge. Based on a unique data set obtained from a large multi-national corporation, I examined three different aspects of knowledge seeking and…

  16. Structuring Job Related Information on the Intranet: An Experimental Comparison of Task vs. an Organization-Based Approach

    Science.gov (United States)

    Cozijn, Reinier; Maes, Alfons; Schackman, Didie; Ummelen, Nicole

    2007-01-01

    In this article, we present a usability experiment in which participants were asked to make intensive use of information on an intranet in order to execute job-related tasks. Participants had to work with one of two versions of an intranet: one with an organization-based hyperlink structure, and one with a task-based hyperlink structure.…

  17. Key Problems in Organizing and Structuring University Research in Vietnam: The Lack of an Effective Research "Behaviour Formalization" System

    Science.gov (United States)

    Nguyen, Huong Thi Lan; Meek, Vincent Lynn

    2016-01-01

    Structure and organization seems to be at the root of many of the questions raised about institutional behaviour; however, with respect to research on university capacity building, few studies have examined research organizational problems, particularly in developing countries. This study investigates academic reactions to the structure and…

  18. Organization of the rabbit vitreous body : Lamellae, Cloquet's channel and a novel structure, the 'alae canalis Cloqueti'

    NARCIS (Netherlands)

    Los, LI; van Luyn, MJA; Nieuwenhuis, P

    1999-01-01

    Even though the rabbit is a frequently used animal model for studies on Vitreous function and pathobiology, data on the structural organization of the rabbit Vitreous are scarce. The aim of the present study is to give a detailed description of rabbit vitreous structure in order to provide a basis f

  19. Bimolecular crystals with an intercalated structure improve poly(p-phenylenevinylene)-based organic photovoltaic cells.

    Science.gov (United States)

    Lim, Kyung-Geun; Park, Jun-Mo; Mangold, Hannah; Laquai, Frédéric; Choi, Tae-Lim; Lee, Tae-Woo

    2015-01-01

    The exciton dissociation, recombination, and charge transport of bulk heterojunction organic photovoltaic cells (OPVs) is influenced strongly by the nanomorphology of the blend, such as the grain size and the molecular packing. Although it is well known that polymers based on amorphous poly(p-phenylenevinylene) (PPV) have a fundamental limit to their efficiency because of low carrier mobility, which leads to increased recombination and unbalanced charge extraction, herein, we demonstrate that the issue can be overcome by forming bimolecular crystals of an amorphous PPV-based polymer:phenyl-C61 -butyric acid methyl ester (PCBM) intercalated structure. We used amorphous poly(2,5-dioctyloxy-p-phenylene vinylene-alt-2',5'-thienylene vinylene) (PPVTV), which has a simple chemical structure. A reasonably high power conversion efficiency (∼3.5 %) was obtained, although the material has an intrinsically amorphous structure and a relatively large band gap (2.0 eV). We demonstrate a correlation between a well-ordered bimolecular crystal of PPVTV:PCBM and an improved hole mobility of a PPVTV:PCBM film compared to a pristine PPVTV film by using 2 D grazing incidence XRD and space-charge-limited current measurements. Furthermore, we show that the bimolecular crystal structure in high-performance OPVs is related to an optimum molecular packing, which is influenced by the PPVTV:PCBM blending ratio, side-chain length, and molecular weight of the PPVTV polymer. Improved charge transport in PPVTV:PCBM bimolecular crystals leads to a fast sweep out of charges and thus suppression of nongeminate recombination under the operating conditions.

  20. Structural Design Principle of Small-Molecule Organic Semiconductors for Metal-Free, Visible-Light-Promoted Photocatalysis.

    Science.gov (United States)

    Wang, Lei; Huang, Wei; Li, Run; Gehrig, Dominik; Blom, Paul W M; Landfester, Katharina; Zhang, Kai A I

    2016-08-01

    Herein, we report on the structural design principle of small-molecule organic semiconductors as metal-free, pure organic and visible light-active photocatalysts. Two series of electron-donor and acceptor-type organic semiconductor molecules were synthesized to meet crucial requirements, such as 1) absorption range in the visible region, 2) sufficient photoredox potential, and 3) long lifetime of photogenerated excitons. The photocatalytic activity was demonstrated in the intermolecular C-H functionalization of electron-rich heteroaromates with malonate derivatives. A mechanistic study of the light-induced electron transport between the organic photocatalyst, substrate, and the sacrificial agent are described. With their tunable absorption range and defined energy-band structure, the small-molecule organic semiconductors could offer a new class of metal-free and visible light-active photocatalysts for chemical reactions.

  1. Electronic structure of planar-quasicycled organic molecules with intramolecular hydrogen bond

    Directory of Open Access Journals (Sweden)

    ALEXEI N. PANKRATOV

    2007-03-01

    Full Text Available By means of the HF/6-311G(d,p method, the electronic structure of the series of organic molecules, among which are malonaldehyde, acetylacetone, thiomalonaldehyde,’the derivatives of aniline 2-XC6H4NH2, phenol 2-XC6H4OH, benzenethiol 2-XC6H4SH (X = CHO, COOH, COO-, NO, NO2, OH, OCH3, SH, SCH3, F, Cl, Br, 8-hydroxyquinoline, 8-mercaptoquinoline, tropolone, has been studied. The intramolecular hydrogen bond (IHB has been established to lead to a local electron redistribution in quasicycle, and primarily to the electron density transfer between the direct IHB participants – from the hydrogen atom toward the proton-aceptor atom. On forming the IHB of the S–H···O type, the electron density in general decreases on the sulphohydryl hydrogen atom and increases on the sulphur atom.

  2. Tuning the Interfacial Electronic Structure at Organic Heterojunctions by Chemical Design.

    Science.gov (United States)

    Mothy, Sébastien; Guillaume, Maxime; Idé, Julien; Castet, Frédéric; Ducasse, Laurent; Cornil, Jérôme; Beljonne, David

    2012-09-01

    Quantum-chemical techniques are applied to assess the electronic structure at donor/acceptor heterojunctions of interest for organic solar cells. We show that electrostatic effects at the interface of model 1D stacks profoundly modify the energy landscape explored by charge carriers in the photoconversion process and that these can be tuned by chemical design. When fullerene C60 molecules are used as acceptors and unsubstituted oligothiophenes or pentacene are used as donors, the uncompensated quadrupolar electric field at the interface provides the driving force for splitting of the charge-transfer states into free charges. This quadrupolar field can be either enhanced by switching from a C60 to a perylene-tetracarboxylic-dianhydride (PTCDA) acceptor or suppressed by grafting electron-withdrawing groups on the donor. PMID:26292117

  3. Experimental and modelling study of organization phenomena in dielectric barrier discharges with structurally inhomogeneous wood substrates

    Science.gov (United States)

    Levasseur, O.; Profili, J.; Gangwar, R. K.; Naudé, N.; Clergereaux, R.; Gherardi, N.; Stafford, L.

    2014-10-01

    The spatial organization of dielectric barrier discharges operating at atmospheric pressure in the presence of complex wood substrates was analysed using optical imaging, current-voltage (I-V) characteristics, and optical emission spectroscopy combined with a collisional-radiative model to extract the average electron energy. The structural inhomogeneities of selected wood species produced non-uniform light emission patterns while maintaining homogeneous-like I-V characteristics and spatially uniform average electron energy. Based on a simple electrical model of the discharge, this localization was ascribed, at least partially, to a spatial modulation of the relative dielectric permittivity on ‘early’ versus ‘late’ wood affecting the local voltage applied to the gas, and thus the local discharge current.

  4. Thienoacene-fused pentalenes: Syntheses, structures, physical properties and applications for organic field-effect transistors

    KAUST Repository

    Dai, Gaole

    2014-11-27

    Three soluble and stable thienoacene-fused pentalene derivatives (1-3) with different π-conjugation lengths were synthesized. X-ray crystallographic analysis and density functional theory (DFT) calculations revealed their unique geometric and electronic structures due to the interaction between the aromatic thienoacene units and antiaromatic pentalene moiety. As a result, they all possess a small energy gap and show amphoteric redox behaviour. Time dependent (TD) DFT calculations were used to explain their unique electronic absorption spectra. These new compounds exhibited good thermal stability and ordered packing in solid state and thus their applications in organic field-effect transistors (OFETs) were also investigated. The highest field-effect hole mobility of 0.016, 0.036 and 0.001 cm2 V-1 s-1 was achieved for solution-processed thin films of 1-3, respectively.

  5. Spin Frustration in an Organic Radical Ion Salt Based on a Kagome-Coupled Chain Structure.

    Science.gov (United States)

    Postulka, Lars; Winter, Stephen M; Mihailov, Adam G; Mailman, Aaron; Assoud, Abdeljalil; Robertson, Craig M; Wolf, Bernd; Lang, Michael; Oakley, Richard T

    2016-08-31

    Electro-oxidation of the quinoidal bisdithiazole BT in dichloroethane in the presence of [Bu4N][GaBr4] affords the 1:1 radical ion salt [BT][GaBr4], crystals of which belong to the trigonal space group P3. The packing pattern of the radical cations provides a rare example of an organic kagome basket structure, with S = 1/2 radical ion chains located at the triangular corners of a trihexagonal lattice. Magnetic measurements over a wide temperature range from 30 mK to 300 K suggest strongly frustrated AFM interactions on the scale of J/kb ∼ 30 K, but reveal no anomalies that would be associated with magnetic order. These observations are discussed in terms of the symmetry allowed magnetic interactions within and between the frustrated layers.

  6. On the inference of function from structure using biomechanical modelling and simulation of extinct organisms.

    Science.gov (United States)

    Hutchinson, John R

    2012-02-23

    Biomechanical modelling and simulation techniques offer some hope for unravelling the complex inter-relationships of structure and function perhaps even for extinct organisms, but have their limitations owing to this complexity and the many unknown parameters for fossil taxa. Validation and sensitivity analysis are two indispensable approaches for quantifying the accuracy and reliability of such models or simulations. But there are other subtleties in biomechanical modelling that include investigator judgements about the level of simplicity versus complexity in model design or how uncertainty and subjectivity are dealt with. Furthermore, investigator attitudes toward models encompass a broad spectrum between extreme credulity and nihilism, influencing how modelling is conducted and perceived. Fundamentally, more data and more testing of methodology are required for the field to mature and build confidence in its inferences. PMID:21666064

  7. Structural organization of water-based ferrofluids with sterical stabilization as revealed by SANS

    Energy Technology Data Exchange (ETDEWEB)

    Balasoiu, M. [Institute of Space Sciences, Bucharest (Romania) and Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna (Russian Federation)]. E-mail: balasoiumaria@yahoo.com; Avdeev, M.V. [Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna (Russian Federation); Lomonosov Moscow State University (Russian Federation); Aksenov, V.L. [Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna (Russian Federation); Lomonosov Moscow State University (Russian Federation); Hasegan, D. [Institute of Space Sciences, Bucharest (Romania); Garamus, V.M. [GKSS Research Centre, Geesthacht (Germany); Schreyer, A. [GKSS Research Centre, Geesthacht (Germany); Bica, D. [Center for Fundamental and Advanced Technical Research, Timisoara (Romania); Vekas, L. [Center for Fundamental and Advanced Technical Research, Timisoara (Romania)

    2006-05-15

    Small-angle neutron scattering (SANS) with contrast variation is applied to reveal structural organization of a water-based ferrofluid where magnetite nanoparticles are sterically stabilized by the double layer of dodecylbenzenesulphonic acid (DBS). The contrast is changed by the use of different ratios between light and heavy water in the carrier. The modified basic functions are introduced and determined following the analysis of the shape scattering from the colloidal particles in the fluid. Three types of particles are detected, which are presumably initial particles (size {approx}20 nm), secondary fractal aggregates (size >250 nm) and micelles of DBS (size {approx}5 nm). The found effective match point (35% of D{sub 2}O) gives the 26 vol% content of magnetite in the initial particles.

  8. Structural Characterization and Infrared and Electrical Properties of the New Inorganic-Organic Hybrid Compound

    Directory of Open Access Journals (Sweden)

    A. Oueslati

    2013-01-01

    Full Text Available New inorganic-organic hybrid [(C3H74N]2Hg2Cl6 compound was obtained and characterised by single-crystal X-ray diffraction, infrared, and impedance spectroscopy. The latter crystallizes in the monoclinic system (space group C 2/c, with the following unit cell dimensions: (1 Å, (6 Å, (2 Å, and (2. Besides, its structure was solved using 84860 independent reflections leading to . Electrical properties of the material were studied using impedance spectroscopic technique at different temperatures in the frequency range of 209 Hz to 5 MHz. Detailed analysis of the impedance spectrum suggested that the electrical properties of the material are strongly temperature-dependent. The Nyquist plots clearly showed the presence of bulk and grain boundary effect in the compound.

  9. Non-targeted Explorations in the Compositional and Structural Space of Natural Organic Matter

    Science.gov (United States)

    Hertkorn, N.; Schmitt-Kopplin, P.; Perdue, E. M.

    2009-05-01

    Natural organic matter (NOM) occurs in soils, freshwater and marine environments, in the atmosphere and in the form of prebiotic organic matter and represents an exceedingly complex mixture of organic compounds that collectively exhibits a nearly continuous range of properties (size-reactivity continuum). The fate NOM in the bio- and geosphere is governed according to the rather fundamental restraints of thermodynamics and kinetics. In these intricate materials, the "classical" signatures of the (geogenic or ultimately biogenic) precursor molecules, like lipids, glycans, proteins and natural products have been attenuated, often beyond recognition, during a succession of biotic and abiotic (e.g. photo- and redox chemistry) reactions. Because of this loss of biochemical signature, these materials can be designated non- repetitive complex systems. The most informative, "bottom-up" approach to molecularly characterize these complex materials necessarily relies upon spectroscopic methods which translate high-precision frequency measurements into very significant molecular-level information. Frequencies can be measured with an accuracy of 15 digits. This extent of accuracy in frequency measurements translates directly into high resolution, itself a very useful and even indispensable feature to produce information-rich data with sufficient resolution to overcome the otherwise common and detrimental effects of intrinsic averaging, which deteriorate spectral resolution to the degree of a bulk-type characterization rather than to a molecular resolution analysis. High-precision frequency measurements, which can be translated into isotope-specific molecular resolution detail of unprecedented significance and richness, define the core of the two most influential methods of organic structural spectroscopy for the investigation of complex materials, namely NMR spectroscopy (provide unsurpassed insight into close-range molecular order to assess the structural space) and FTICR mass

  10. Guest driven structural transformation studies of a luminescent metal-organic framework

    Indian Academy of Sciences (India)

    Biplab Manna; Shweta Singh; Sujit K Ghosh

    2014-09-01

    A two-dimensional (2D) porous metal-organic framework (MOF) [{Zn2(L)4(OTf)4}.2(DCM).xG] (1 ⊃ G) (OTf = trifluoro methane sulfonate, DCM = Dichloromethane, L (1, 4-bis (4-pyridyl)-2, 3-diaza-1, 3-butadiene) synthesized at room temperature. Free guests DCM were encapsulated in the pores of the MOF. On air drying the MOF loses free DCM molecules and changed its structure in a crystal to crystal manner to produce compound 1 [{Zn(L)2(OTf)2}.XG](1). This guest-induced breathing of the framework was also supported from PXRD patterns. Solid state photoluminescence properties of the dynamicMOF were studied at room temperature.

  11. Synthesis and structure of new carbohydrate metal-organic frameworks and inclusion complexes

    Science.gov (United States)

    Sha, Jing-Quan; Wu, Lian-He; Li, Shu-Xian; Yang, Xiao-Ning; Zhang, Yu; Zhang, Qian-Nan; Zhu, Pei-Pei

    2015-12-01

    Two new metal-organic framework compounds based on natural β-cyclodextrin molecules (β-CD) and alkali metals (Na+/K+) were synthesized and characterized by elemental analyses, IR, XPRD and 1HNMR. Single-crystal X-ray diffraction analysis reveals that compounds 1 and 2 possess the bowl-like pore and the "8" type double channels configuration. Due to the [blow + channel] double configuration, 5-Fluorouracil (5-FU) and Quercetin inclusion complexes of compound 1 are studied, and the results show that the two kinds of drug with different structure and size can be included into the compound at the same time, which is expected to become a new type of multi-functional green crystalline solid material.

  12. Synthesis and Crystal Structure of a Novel Zincophosphite Containing Two-dimensional Inorganic-organic Network

    Institute of Scientific and Technical Information of China (English)

    YANG,Ya-Li(杨雅莉); LI,Niu(李牛); XIANG,Shou-He(项寿鹤)

    2004-01-01

    A novel 1,6-hexamethylenediamine-zincophosphite has been synthesized hydrothermally.Its single-crystal structure refinement has shown the zincophosphite with the composition(CH2)6[Zn(HPO3)2]2-,Mr=343.55.It crystallizes in monoclinic,space group C2/c(No.15),a=2.2391nm,b=0.8695nm,c=0.7919nm,β=101.062(6)°,V=1.513nm3,Dc=1.508kg/m3,Z=4,F(000)=712,μ=1.849mm-1,R1=0.0416,Wr2=0.1023.This phase exhibits infinite inorganic chains of vertex-linked ZnO4 and HPO3.Via the electrostatic attraction,1,6-hexamethylenediamine cations and inorganic chains construct a novel interesting two-dimensional inorganic-organic network.

  13. Bio-Inspired electro-photonic structure for organic and dye sensitized solar cells

    Science.gov (United States)

    Lopez, Rene

    2011-03-01

    A major challenge in solar cell technology dwells in achieving an efficient absorption of photons with an effective carrier extraction. In all cases, light absorption considerations call for thicker modules while carrier transport would benefit from thinner ones. This dichotomy is a fundamental problem limiting the efficiencies of most photovoltaics. One pathway to overcome this problem is to decouple light absorption from carrier collection. We present solutions to this problem applying bio-inspired nanostructures to two different types of systems: organic photovoltaic (OPV) and dye sensitized solar cells (DSSC). For OPV devices based on poly-3-hexylthiophene:[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM), we describe a 2-D photonic crystal geometry that enhances the absorption of polymer-fullerene photonic cells ~ 20 % relative to conventional planar cells. Remarkably, the photonic crystal cell offers the possibility to increase photocurrents by improvements in optical absorption and carrier extraction simultaneously, and particularly through the excitation of photonic resonant modes near the band edge of organic PV materials. We also present an optical method to extract charge transport lengths from device photoactive layers. For DSSCs we introduce a new structural motif for the photoanode in which the traditional random nanoparticle oxide network is replaced by vertically aligned bundles of oxide nanocrystals. We have used a pulsed laser deposition system to ablate titanium oxide targets to obtain the porous and vertically aligned structures for enhanced photoelectrochemical performance. Absorption studies show that in optimized structures for titanium oxide, there is a 1.4 times enhancement of surface area compared to the best sol-gel films, Incident-Photon-Conversion-Efficiency values are better than 3 times thicker sol-gel films, and ~ 92 % Absorbed-Photon-Conversion-Efficiency values have been observed when sensitizing with the N3 dye (Ru(dcbpyH)2

  14. A randomly nano-structured scattering layer for transparent organic light emitting diodes

    Science.gov (United States)

    Huh, Jin Woo; Shin, Jin-Wook; Cho, Doo-Hee; Moon, Jaehyun; Joo, Chul Woong; Park, Seung Koo; Hwang, Joohyun; Cho, Nam Sung; Lee, Jonghee; Han, Jun-Han; Chu, Hye Yong; Lee, Jeong-Ik

    2014-08-01

    A random scattering layer (RSL) consisting of a random nano-structure (RNS) and a high refractive index planarization layer (HRI PL) is suggested and demonstrated as an efficient internal light-extracting layer for transparent organic light emitting diodes (TOLEDs). By introducing the RSL, a remarkable enhancement of 40% and 46% in external quantum efficiency (EQE) and luminous efficacy (LE) was achieved without causing deterioration in the transmittance. Additionally, with the use of the RSL, the viewing angle dependency of EL spectra was reduced to a marginal degree. The results were interpreted as the stronger influence of the scattering effect over the microcavity. The RSL can be applied widely in TOLEDs as an effective light-extracting layer for extracting the waveguide mode of confined light at the indium tin oxide (ITO)/OLED stack without introducing spectral changes in TOLEDs.A random scattering layer (RSL) consisting of a random nano-structure (RNS) and a high refractive index planarization layer (HRI PL) is suggested and demonstrated as an efficient internal light-extracting layer for transparent organic light emitting diodes (TOLEDs). By introducing the RSL, a remarkable enhancement of 40% and 46% in external quantum efficiency (EQE) and luminous efficacy (LE) was achieved without causing deterioration in the transmittance. Additionally, with the use of the RSL, the viewing angle dependency of EL spectra was reduced to a marginal degree. The results were interpreted as the stronger influence of the scattering effect over the microcavity. The RSL can be applied widely in TOLEDs as an effective light-extracting layer for extracting the waveguide mode of confined light at the indium tin oxide (ITO)/OLED stack without introducing spectral changes in TOLEDs. Electronic supplementary information (ESI) available: Simulation results of total (bottom and top) radiance of TOLEDs with the RSL depending on HTL and ETL thicknesses. See DOI: 10.1039/c4nr01520g

  15. Periodic surface structures on titanium self-organized upon double femtosecond pulse exposures

    Energy Technology Data Exchange (ETDEWEB)

    Gemini, Laura, E-mail: gemini@fzu.cz [Advanced Research Center for Beam Science, Institute for Chemical Research, Kyoto University Uji, Kyoto 611-0011 (Japan); Department of Physics, Graduate School of Science, Kyoto University, 606-8502 Kyoto (Japan); FNSPE, Czech Technical University in Prague, Brehova 7, 11519 Prague (Czech Republic); HiLASE Centre, Institute of Physics, ASCR, Za Radnicí 828, 25241 Dolní Břežany (Czech Republic); Hashida, Masaki; Miyasaka, Yasuhiro; Inoue, Shunsuke [Advanced Research Center for Beam Science, Institute for Chemical Research, Kyoto University Uji, Kyoto 611-0011 (Japan); Department of Physics, Graduate School of Science, Kyoto University, 606-8502 Kyoto (Japan); Limpouch, Jiri [FNSPE, Czech Technical University in Prague, Brehova 7, 11519 Prague (Czech Republic); Mocek, Tomas [HiLASE Centre, Institute of Physics, ASCR, Za Radnicí 828, 25241 Dolní Břežany (Czech Republic); Sakabe, Shuji [Advanced Research Center for Beam Science, Institute for Chemical Research, Kyoto University Uji, Kyoto 611-0011 (Japan); Department of Physics, Graduate School of Science, Kyoto University, 606-8502 Kyoto (Japan)

    2015-05-01

    Highlights: • LIPSS self-formed on Ti surface upon irradiations by 25 double pulses. • A surface plasma density variation leads to a variation of LIPSS features. • Data from double pulse irradiations well agree with the parametric decay model. • Results confirm the formation of surface plasma during the ultra-short interaction. • Results support once again the validity of the parametric decay model. - Abstract: Laser induced periodic surface structures (LIPSS) self-organized on Ti surface after irradiations by femtosecond laser beam composed by double pulses with a fixed time delay of 160 fs. The fluence of the first pulse (F{sub PP}), responsible for surface plasma formation, was varied in the range 10–50 mJ cm{sup −2} and always kept below the LIPSS formation threshold fluence (F{sub LIPSS}) on Ti for 50-single-shots exposure. The fluence of the delayed pulse (F{sub LP}), responsible for LIPSS self-organization, was varied in the range 60–150 mJ cm{sup −2} and always kept above F{sub LIPSS}. Regardless the specific fluence F{sub LP} of the delayed pulse, the interspace of the grating structures increases with the increase of F{sub PP}, that is an increase of the surface plasma density. This tendency suggests that a variation of the surface plasma density, due to a variation of F{sub PP}, actually leads to a modification of the grating features. Moreover, we observed that the LIPSS periodicities after double pulse exposures are in quite good agreement with data on LIPSS periodicities after single 160 fs pulse irradiations on Ti surface and with the curve predicted by the parametric decay model. This experimental result suggests that the preformed plasma might be produced in the rising edge of the temporal profile of the laser pulse.

  16. High Resolution Imaging of Defect Structures in Polymer and Organic Molecular Crystals

    Science.gov (United States)

    Martin, David

    2003-03-01

    We have been developing techniques for the low dose High Resolution Electron Microscopy (HREM) imaging of defect structures in polymer and organic molecular crystals. We have examined a variety of technologically important materials systems including rigid-rod polymers, poly(imides), poly(diacetylenes), poly(bisthiazoles), poly(bisoxazoles), and aromatic polyamides such as poly(paraphenylene terephthalamide) (PPTA or Kevlar(R)) and poly(metaphenylene diisophthalamide) (MPDI or Nomex(R)). These studies have made it possible for us to image the molecular reorganization in the vicinity of dislocations, surfaces, and grain boundaries. We have also learned about the micromechanisms of lattice bending and twisting. Most recently we have been examining the microstructure of pentacene, a highly-crystalline conjugated organic small molecule that is of interest for making flexible electronic devices such as thin-film transistors. We have also been examing the utility of low voltage techniques using a table-top sized electron microscope that operates near 5 kV.

  17. Primary structure of the human follistatin precursor and its genomic organization

    International Nuclear Information System (INIS)

    Follistatin is a single-chain gonadal protein that specifically inhibits follicle-stimulating hormone release. By use of the recently characterized porcine follistatin cDNA as a probe to screen a human testis cDNA library and a genomic library, the structure of the complete human follistatin precursor as well as its genomic organization have been determined. Three of eight cDNA clones that were sequenced predicted a precursor with 344 amino acids, whereas the remaining five cDNA clones encoded a 317 amino acid precursor, resulting from alternative splicing of the precursor mRNA. Mature follistatins contain four contiguous domains that are encoded by precisely separated exons; three of the domains are highly similar to each other, as well as to human epidermal growth factor and human pancreatic secretory trypsin inhibitor. The genomic organization of the human follistatin is similar to that of the human epidermal growth factor gene and thus supports the notion of exon shuffling during evolution

  18. Beyond static structures: Putting forth REMD as a tool to solve problems in computational organic chemistry.

    Science.gov (United States)

    Petraglia, Riccardo; Nicolaï, Adrien; Wodrich, Matthew D; Ceriotti, Michele; Corminboeuf, Clemence

    2016-01-01

    Computational studies of organic systems are frequently limited to static pictures that closely align with textbook style presentations of reaction mechanisms and isomerization processes. Of course, in reality chemical systems are dynamic entities where a multitude of molecular conformations exists on incredibly complex potential energy surfaces (PES). Here, we borrow a computational technique originally conceived to be used in the context of biological simulations, together with empirical force fields, and apply it to organic chemical problems. Replica-exchange molecular dynamics (REMD) permits thorough exploration of the PES. We combined REMD with density functional tight binding (DFTB), thereby establishing the level of accuracy necessary to analyze small molecular systems. Through the study of four prototypical problems: isomer identification, reaction mechanisms, temperature-dependent rotational processes, and catalysis, we reveal new insights and chemistry that likely would be missed using static electronic structure computations. The REMD-DFTB methodology at the heart of this study is powered by i-PI, which efficiently handles the interface between the DFTB and REMD codes.

  19. Organic compounds containing methoxy and cyanoacrylic acid: Synthesis, characterization, crystal structures, and theoretical studies

    Energy Technology Data Exchange (ETDEWEB)

    Khalaji, A. D., E-mail: alidkhalaji@yahoo.com [Golestan University, Department of Chemistry, Faculty of Science (Iran, Islamic Republic of); Maddahi, E. [Iran University of Science & Technology, Ms.C Educated, Department of Chemistry (Iran, Islamic Republic of); Dusek, M.; Fejfarova, K. [Institute of Physics of the ASCR, v.v.i. (Czech Republic); Chow, T. J. [Academia Sinica, Institute of Chemistry (China)

    2015-12-15

    Metal-free organic compounds 24-SC ((E)-2-cyano-3-(2,4-dimethoxyphenyl)acrylic acid) and 34-SC ((E)-2-cyano-3-(3,4-dimethoxyphenyl)acrylic acid), containing methoxy groups as a donor and the acrylic acid as an acceptor were synthesized and characterized by CHN, FT-IR, UV-Vis, {sup 1}H-NMR and single crystal X-ray diffraction and used as photosensitizers for the application of dye-sensitized solar cells (DSSC). The sensitizing characteristics of them were evaluated. Both compounds contain the natural molecule, its anionic form and the piperidinium cation and they differ by number of these molecules in the asymmetric unit. To get further insight into the effect of molecular structure on the performance of DSSC, their geometry and energies of HOMO and LUMO were optimized by density functional theory calculation at the B3LYP/6-31G(d) level with Gaussian 03. Overall conversion efficiencies of 0.78 under full sunlight irradiation are obtained for DSSCs based on the new metal-free organic dyes 24-SC and 34-SC.

  20. Interface properties and electronic structure of PCPDTBT - a promising polymer for organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Ayguel, Umut; Petraki, Fotini; Hintz, Holger; Peisert, Heiko; Chasse, Thomas [Institute of Physical and Theoretical Chemistry, University of Tuebingen (Germany)

    2010-07-01

    Mankind's energy demand is steadily increasing. Novel techniques for environmental friendly energy conversion are therefore a challenging task. Organic solar cells based on donor-acceptor blends present a quite new approach, which posses a large market potential although their efficiency is rather low compared to their inorganic counterparts. In polymer based ''bulk heterojunction''-type solar cells so-called ''low bandgap'' materials are promising donor components in active layers. Low optical bandgap conjugated polymers may improve the efficiency of organic photovoltaic devices by increasing the absorption in the visible and near infrared region of the solar spectrum and by optimizing the offset of the LUMO (lowest unoccupied molecular orbital) energy levels of the donor and acceptor. A potential candidate in this context is Poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b'] dithiophene)-alt-4,7(2,1,3-benzothiadiazole)] (PCPDTBT). We study the electronic structure and interface properties to gold and ITO of PCPDTBT by X-ray and UV photoemission spectroscopies (XPS, UPS) as well as X-ray absorption spectroscopy (XAS). The energy level alignment points to charge transfer processes across the interface. In addition, strong chemical interactions occur which may have consequences for interface properties in devices.

  1. Anatomical structure of Trapa natans L. submerged organs in context of the species ecology

    Directory of Open Access Journals (Sweden)

    Olena M. Nedukha

    2015-05-01

    Full Text Available The results of anatomical study of submerged organs of Trapa natans (water chestnut in budding-flowering stage are presented. The plants were collected along the shore of the Rusanivsky channel (left shore of Dnepr River, in Kiev. The light and laser scanning confocal microscopy were used. Anatomical structure of the submerged secondary roots, the submerged dissected leaves and stem had the signs that are typical for submerged organs of some hydrophytes. But, the roots are characterized by the peculiarity, they were photosynthesizing. Chloroplasts are revealed in root core cells. The middle number of chloroplasts in one parenchyma cell of submerged leaf was four times more than in one core cell of root. The fluorescence intensity of leaf chloroplasts was also more than that in root or stem chloroplasts. The very developed aerenchyma was characterized for roots and submerged stem in comparison with the submerged dissected leaves, in which an aerenchyma was weak developed and it was presented by very small air space between the cells of inner layer in parenchyma.

  2. Crosslinked copolyazoles with a zwitterionic structure for organic solvent resistant membranes

    KAUST Repository

    Chisca, Stefan

    2015-01-01

    The preparation of crosslinked membranes with a zwitterionic structure based on a facile reaction between a newly synthesized copolyazole with free OH groups and (3-glycidyloxypropyl)trimethoxysilane (GPTMS) is reported. The new OH-functionalized copolyazole is soluble in common organic solvents, such as tetrahydrofuran (THF), dimethylsulfoxide (DMSO), N,N′-dimethylformamide (DMF) and N-methyl-2-pyrrolidone (NMP) and can be easily processed by phase inversion. After crosslinking with GPTMS, the membranes acquire high solvent resistance. We show the membrane performance and the influence of the crosslinking reaction conditions on the thermal stability, surface polarity, pore morphology, and solvent resistance. By using UV-spectroscopy we monitored the solvent resistance of the membranes in four aggressive solvents (THF, DMSO, DMF and NMP) for 30 days. After this time, only minor changes (less than 2%) were detected for membranes subjected to a crosslinking reaction for 6 hours or longer. Our data suggest that the novel crosslinked membranes can be used for industrial applications in wide harsh environments in the presence of organic solvents.

  3. Electronic structure of ultra thin organic hetero-interfaces - SnPc/PTCDA/Ag(111)

    Energy Technology Data Exchange (ETDEWEB)

    Schoell, Achim; Haeming, Marc; Greif, Michael; Wiessner, Michael [Universitaet Wuerzburg, Experimentelle Physik VII, D-97074 Wuerzburg (Germany); Reinert, Friedrich [Universitaet Wuerzburg, Experimentelle Physik VII, D-97074 Wuerzburg (Germany); Karlsruhe Institute of Technology, Gemeinschaftslabor fuer Nanoanalytik, D-76021 Karlsruhe (Germany)

    2010-07-01

    While the interfaces of molecules to a substrate have been studied extensively, knowledge about the interface between different molecular compounds is still relatively scarce. This is to some extend caused by the fact that these interfaces, which are of great relevance for opto-electronic devices consisting out of multiple organic compounds, are more complicated to access experimentally. Structurally well defined model systems, which allow for a systematic and detailed investigation of the interface characteristics, are thus of great importance. In this work we provide data from x-ray absorption and photoelectron spectroscopy on the organic heterolayer system tin-phthalocyanine (SnPc)/perylen-tetracarboxylicacid dianhydride (PTCDA). We show, that SnPc, prepared on a Ag(111) surface precovered by a monolayer of PTCDA, forms a well defined interface with a closed first layer of flat lying molecules. Moreover, the bonding of the SnPc molecules to the PTCDA interlayer is clearly non-covalent and a detailed inspection of the valence spectra shows that the respective molecular signatures can be distinguished well. The SnPc/PTCDA/Ag(111) system is thus well-suited for further investigations employing complicated techniques.

  4. Primary structure of the human follistatin precursor and its genomic organization

    Energy Technology Data Exchange (ETDEWEB)

    Shimasaki, Shunichi; Koga, Makoto; Esch, F.; Cooksey, K.; Mercado, M.; Koba, A.; Ueno, Naoto; Ying, Shaoyao; Ling, N.; Guillemin, R. (Salk Institute, La Jolla, CA (USA))

    1988-06-01

    Follistatin is a single-chain gonadal protein that specifically inhibits follicle-stimulating hormone release. By use of the recently characterized porcine follistatin cDNA as a probe to screen a human testis cDNA library and a genomic library, the structure of the complete human follistatin precursor as well as its genomic organization have been determined. Three of eight cDNA clones that were sequenced predicted a precursor with 344 amino acids, whereas the remaining five cDNA clones encoded a 317 amino acid precursor, resulting from alternative splicing of the precursor mRNA. Mature follistatins contain four contiguous domains that are encoded by precisely separated exons; three of the domains are highly similar to each other, as well as to human epidermal growth factor and human pancreatic secretory trypsin inhibitor. The genomic organization of the human follistatin is similar to that of the human epidermal growth factor gene and thus supports the notion of exon shuffling during evolution.

  5. Exploring how organic matter controls structural transformations in natural aquatic nanocolloidal dispersions.

    Science.gov (United States)

    King, Stephen M; Jarvie, Helen P

    2012-07-01

    The response of the dispersion nanostructure of surface river bed sediment to the controlled removal and readdition of natural organic matter (NOM), in the absence and presence of background electrolyte, was examined using the technique of small-angle neutron scattering (SANS). Partial NOM removal induced aggregation of the mineral particles, but more extensive NOM removal restored colloidal stability. When peat humic acid (PHA) was added to a NOM-deficient sediment concentration-related structural transformations were observed: at 255 mg/L PHA aggregation of the nanocolloid was actually enhanced, but at 380 mg/L PHA disaggregation and colloidal stability were promoted. The addition of 2 mM CaCl(2) induced mild aggregation in the native sediment but not in sediments with added PHA, suggesting that the native NOM and the PHA respond differently to changes in ionic strength. A first attempt at using SANS to directly characterize the thickness and coverage of an adsorbed PHA layer in a natural nanocolloid is also presented. The results are discussed in the context of a hierarchical aquatic colloidal nanostructure, and the implications for contemporary studies of the role of dissolved organic carbon (DOC) in sustaining the transport of colloidal iron in upland catchments.

  6. INSTITUTIONAL STRUCTURE DEVELOMENT IN THE FIELD OF ORGANIC FARMING IN TURKEY

    OpenAIRE

    KARAARSLAN, VİLDAN

    2014-01-01

    Practices in the field of organic farming have been carried out within the scope of legal framework since 2003. In Turkey, organic farming activities are conducted under the auspices of Department of Good Agriculture Practices and Organic Farming of the General Directorate of Plant Production of the Ministry of Food Agriculture and Livestock. There are Organic Farming Committee and Organic Farming National Guidance Committee. Besides, there are Organic Farming Units in 81 Provincial Directora...

  7. Angular Dependence of the Sharply Directed Emission in Organic Light Emitting Diodes with a Microcavity Structure

    Science.gov (United States)

    Juang, Fuh-Shyang; Laih, Li-Hong; Lin, Chia-Ju; Hsu, Yu-Jen

    2002-04-01

    An optical microcavity structure was used in organic light emitting diodes. We succeeded in fabricating a device with sharply directed emission vertical to an emission surface. The device shows green emission (bright green) at normal position which turns red (bright red) at the 30° position. The angular dependences of the electroluminescence and the emission patterns versus viewing angle in the microcavity OLED were studied. The resonance wavelength λ decreases with viewing angle. The emission peak at 490 nm is directed vertically to the device surface more sharply than that at 632 nm. The microcavity structure shows non-Lambertian emission. The spectra appear more blue off-axis and the intensity of the green-like emission decreases rapidly with increasing viewing angle. A significantly narrow linewidth of 7.4 nm in the 0° direction for the 490 nm peak was observed. The full-widths at half maximum (FWHM) of the green-like spectra are much smaller than those of the red-like ones, indicating better cavity quality.

  8. Spatial organization and correlation properties quantify structural changes on mesoscale of parenchymatous plant tissue

    International Nuclear Information System (INIS)

    The study of plant tissue parenchyma's intercellular air spaces contributes to the understanding of anatomy and physiology. This is challenging due to difficulty in making direct measurements of the pore space and the complex mosaic of parenchymatous tissue. The architectural complexity of pore space has shown that single geometrical measurements are not sufficient for characterization. The inhomogeneity of distribution depends not only on the percentage content of phase, but also on how the phase fills the space. The lacunarity morphometric, as multiscale measure, provides information about the distribution of gaps that correspond to degree of spatial organization in parenchyma. Additionally, modern theories have suggested strategies, where the focus has shifted from the study of averages and histograms to the study of patterns in data fluctuations. Detrended fluctuation analysis provides information on the correlation properties of the parenchyma at different spatial scales. The aim is to quantify (with the aid of the aforementioned metrics), the mesostructural changes—that occur from one cycle of freezing and thawing—in the void phase of pome fruit parenchymatous tissue, acquired with X-ray microcomputed tomography. Complex systems methods provide numerical indices and detailed insights regarding the freezing-induced modifications upon the arrangement of cells and voids. These structural changes have the potential to lead to physiological disorders. The work can further stimulate interest for the analysis of internal plant tissue structures coupled with other physico-chemical processes or phenomena

  9. Synthesis, crystal structure, spectroscopic, thermal and dielectric properties of a novel semi-organic pentachloroantimonate (III)

    Science.gov (United States)

    Lahbib, Ikram; Rzaigui, Mohamed; Smirani, Wajda

    2016-09-01

    A new organic-inorganic hybrid material of formula (C10H15N2F)5(SbCl5)5.2H2O was synthesized and characterized by X-Ray diffraction analysis. It crystallizes in the monoclinic space group P21/c with the following unit cell parameters a = 15.819(4) Å, b = 17.685(3) Å, c = 30.529(4) Å, Z = 4 and V = 8540(3) Å3. The examination of the structure shows that the three-dimensional frameworks are produced by Nsbnd H⋯Cl, Nsbnd H⋯O, Csbnd H⋯Cl and Nsbnd H⋯F, Csbnd H⋯F hydrogen bonding and Cl⋯Cl interactions. IR, Raman and UV-Visible spectroscopies were also used to characterize this compound. In addition, the fluorescent properties of this compound have been investigated in the liquid state at room temperature. Differential scanning calorimetry (DSC) has revealed a structural phase transition of the order-disorder type around 370 K. Dielectric investigations revealed a step-wise change of the electric permittivity at Ttr characteristic of the crystal in the high-temperature phase. The evolution of dielectric constant as a function of temperature of the sample has been investigated in order to determine some related parameters. Measurements of AC conductivity as a function of frequency at different temperatures indicated a hopping conduction mechanism and/or reorientational motion.

  10. Electronic Structure of Fullerene Acceptors in Organic Bulk-Heterojunctions: A Combined EPR and DFT Study.

    Science.gov (United States)

    Mardis, Kristy L; Webb, Jeremy N; Holloway, Tarita; Niklas, Jens; Poluektov, Oleg G

    2015-12-01

    Organic photovoltaic (OPV) devices are a promising alternative energy source. Attempts to improve their performance have focused on the optimization of electron-donating polymers, while electron-accepting fullerenes have received less attention. Here, we report an electronic structure study of the widely used soluble fullerene derivatives PC61BM and PC71BM in their singly reduced state, that are generated in the polymer:fullerene blends upon light-induced charge separation. Density functional theory (DFT) calculations characterize the electronic structures of the fullerene radical anions through spin density distributions and magnetic resonance parameters. The good agreement of the calculated magnetic resonance parameters with those determined experimentally by advanced electron paramagnetic resonance (EPR) allows the validation of the DFT calculations. Thus, for the first time, the complete set of magnetic resonance parameters including directions of the principal g-tensor axes were determined. For both molecules, no spin density is present on the PCBM side chain, and the axis of the largest g-value lies along the PCBM molecular axis. While the spin density distribution is largely uniform for PC61BM, it is not evenly distributed for PC71BM. PMID:26569578

  11. Spatial organization and correlation properties quantify structural changes on mesoscale of parenchymatous plant tissue

    Science.gov (United States)

    Valous, N. A.; Delgado, A.; Drakakis, K.; Sun, D.-W.

    2014-02-01

    The study of plant tissue parenchyma's intercellular air spaces contributes to the understanding of anatomy and physiology. This is challenging due to difficulty in making direct measurements of the pore space and the complex mosaic of parenchymatous tissue. The architectural complexity of pore space has shown that single geometrical measurements are not sufficient for characterization. The inhomogeneity of distribution depends not only on the percentage content of phase, but also on how the phase fills the space. The lacunarity morphometric, as multiscale measure, provides information about the distribution of gaps that correspond to degree of spatial organization in parenchyma. Additionally, modern theories have suggested strategies, where the focus has shifted from the study of averages and histograms to the study of patterns in data fluctuations. Detrended fluctuation analysis provides information on the correlation properties of the parenchyma at different spatial scales. The aim is to quantify (with the aid of the aforementioned metrics), the mesostructural changes—that occur from one cycle of freezing and thawing—in the void phase of pome fruit parenchymatous tissue, acquired with X-ray microcomputed tomography. Complex systems methods provide numerical indices and detailed insights regarding the freezing-induced modifications upon the arrangement of cells and voids. These structural changes have the potential to lead to physiological disorders. The work can further stimulate interest for the analysis of internal plant tissue structures coupled with other physico-chemical processes or phenomena.

  12. Hydrothermal Synthesis, Crystal Structure and Luminescent Properties of an Organically Templated 2-D Uranyl Sulfate

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    An organically templated 2-D uranyl sulfate, {(C2H8N)[(UO2)Cl(SO4)(H2O)]}n 1, has been hydrothermally synthesized . The crystal and molecular structures have been determined by X-ray crystallography method and spectral techniques. 1 belongs to mono- clinic, space group P21/c with a = 8.3545(17), b = 10.550(2), c = 12.370(3)(A), β = 102.64(3)°, V = 1063.9(4)(A)3, Mr = 464.64, Dc = 2.901 g/cm3, F(000) = 836, μ = 15.710 mm-1, Z = 4, the final R = 0.0286 and wR = 0.0685 for 10164 observed reflections with I > 2σ(I). 1 presents a two-dimensional layer-like structure constructed from infinite anionic [(UO2)Cl(H2O)(SO4)]- layers with [C2H8N]+ cations balancing the charge and a number of intermolecular hydrogen bonds (C-H…O and O-H…Cl) existing in the solid state. The fluorescence properties of 1 have also been discussed.

  13. Electronic Structure of Fullerene Acceptors in Organic Bulk-Heterojunctions. A Combined EPR and DFT Study

    Energy Technology Data Exchange (ETDEWEB)

    Mardis, Kristy L. [Chicago State Univ., IL (United States); Webb, J. [Chicago State Univ., IL (United States); Holloway, Tarita [Chicago State Univ., IL (United States); Niklas, Jens [Argonne National Lab. (ANL), Argonne, IL (United States); Poluektov, Oleg G. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-11-16

    Organic photovoltaic (OPV) devices are a promising alternative energy source. Attempts to improve their performance have focused on the optimization of electron-donating polymers, while electron-accepting fullerenes have received less attention. Here, we report an electronic structure study of the widely used soluble fullerene derivatives PC61BM and PC71BM in their singly reduced state, that are generated in the polymer:fullerene blends upon light-induced charge separation. Density functional theory (DFT) calculations characterize the electronic structures of the fullerene radical anions through spin density distributions and magnetic resonance parameters. The good agreement of the calculated magnetic resonance parameters with those determined experimentally by advanced electron paramagnetic resonance (EPR) allows the validation of the DFT calculations. Thus, for the first time, the complete set of magnetic resonance parameters including directions of the principal g-tensor axes were determined. For both molecules, no spin density is present on the PCBM side chain, and the axis of the largest g-value lies along the PCBM molecular axis. While the spin density distribution is largely uniform for PC61BM, it is not evenly distributed for PC71BM.

  14. Structural basis for integration of GluD receptors within synaptic organizer complexes.

    Science.gov (United States)

    Elegheert, Jonathan; Kakegawa, Wataru; Clay, Jordan E; Shanks, Natalie F; Behiels, Ester; Matsuda, Keiko; Kohda, Kazuhisa; Miura, Eriko; Rossmann, Maxim; Mitakidis, Nikolaos; Motohashi, Junko; Chang, Veronica T; Siebold, Christian; Greger, Ingo H; Nakagawa, Terunaga; Yuzaki, Michisuke; Aricescu, A Radu

    2016-07-15

    Ionotropic glutamate receptor (iGluR) family members are integrated into supramolecular complexes that modulate their location and function at excitatory synapses. However, a lack of structural information beyond isolated receptors or fragments thereof currently limits the mechanistic understanding of physiological iGluR signaling. Here, we report structural and functional analyses of the prototypical molecular bridge linking postsynaptic iGluR δ2 (GluD2) and presynaptic β-neurexin 1 (β-NRX1) via Cbln1, a C1q-like synaptic organizer. We show how Cbln1 hexamers "anchor" GluD2 amino-terminal domain dimers to monomeric β-NRX1. This arrangement promotes synaptogenesis and is essential for D: -serine-dependent GluD2 signaling in vivo, which underlies long-term depression of cerebellar parallel fiber-Purkinje cell (PF-PC) synapses and motor coordination in developing mice. These results lead to a model where protein and small-molecule ligands synergistically control synaptic iGluR function. PMID:27418511

  15. Structural analysis of organic films by electron diffraction at high and low energy

    Science.gov (United States)

    Stevens, Michael Richard

    This dissertation concerns the importance of electron diffraction as a structural tool in the analysis of organic crystalline materials, focusing on those specimens for which X-ray analysis is insufficient. It extends the range of knowledge needed for solving common problems that occur in such analysis: sample preparation, damage processes, extraction of crystallographic phases, and specimen irregularities. This research reports the first direct measurement of electron beam damage in transmission for beam energies below the carbon-K edge and in part extends the research of Howie, Isaacson, Fryer, and others. Here, it is confirmed that a correlation exists between the carbon-K shell ionization and the damage cross section by direct measurement of spot fading in transmission at beam energies ranging from 200eV to 1000eV. The threshold in damage was directly measured confirming the hypothesis linking K shell ionization to damage in the aromatic specimens; however, for the aliphatic specimens, the threshold effects were not as significant, indicating the importance of other damage processes which are explained. Calculations based on the experimental data show a region of beam energy which may be utilized to image single molecules, in contradiction to previous theory. Utilizing energy filtering, Kohler mode, cryo-microscopy, and standard low-dose techniques, the structures of two organic specimens which could not be solved by X-ray are solved by electron diffraction. These specimens exhibited high sensitivity to the electron beam and were thought good candidates for the project. The first is a Diacetylene polymer 1,2 bis (10,12 tricosadiynoyl)-sn-glycero-3phosphocholine (DC89PC) with a large unit cell, here only a partial structure solution was possible by Direct Methods (DM) phasing and chemical modeling. The full solution will require new sample preparation techniques. Film bending was observed directly, and the resulting effects to the diffraction data are explained

  16. Do differences in food web structure between organic and conventional farms affect the ecosystem service of pest control?

    Science.gov (United States)

    Macfadyen, Sarina; Gibson, Rachel; Polaszek, Andrew; Morris, Rebecca J; Craze, Paul G; Planqué, Robert; Symondson, William O C; Memmott, Jane

    2009-03-01

    While many studies have demonstrated that organic farms support greater levels of biodiversity, it is not known whether this translates into better provision of ecosystem services. Here we use a food-web approach to analyse the community structure and function at the whole-farm scale. Quantitative food webs from 10 replicate pairs of organic and conventional farms showed that organic farms have significantly more species at three trophic levels (plant, herbivore and parasitoid) and significantly different network structure. Herbivores on organic farms were attacked by more parasitoid species on organic farms than on conventional farms. However, differences in network structure did not translate into differences in robustness to simulated species loss and we found no difference in percentage parasitism (natural pest control) across a variety of host species. Furthermore, a manipulative field experiment demonstrated that the higher species richness of parasitoids on the organic farms did not increase mortality of a novel herbivore used to bioassay ecosystem service. The explanation for these differences is likely to include inherent differences in management strategies and landscape structure between the two farming systems.

  17. Insight into sodium silicate glass structural organization by multinuclear NMR combined with first-principles calculations

    International Nuclear Information System (INIS)

    Short and medium range order of silica and sodium silicate glasses have been investigated from a quantitative analysis of 29Si MAS NMR and 23Na, 17O MQMAS NMR spectra. The method described enables the extraction of the underlying 17O NMR parameter distributions of bridging oxygens (BOs) and non-bridging oxygens (NBOs), and yields site populations which are confirmed by 29Si NMR data. The extracted NMR parameter distributions and their variations with respect to the glass chemical composition can then be analyzed in terms of local structural features (bond angles and bond lengths, coordination numbers) with the help of molecular dynamics simulations combined with first-principles calculations of NMR parameters. Correlations of relevant structural parameters with 23Na, 29Si and 17O NMR interactions (isotropic chemical shift δ(iso), quadrupolar coupling constant C(Q) and quadrupolar asymmetry parameter ηQ are re-examined and their applicability is discussed. These data offer better insights into the structural organization of the glass network, including both chemical and topological disorder. Adding sodium to pure silica significantly diminishes the Si-O-Si bond angles and leads to a longer mean Si-O bond length with a slight decrease of the mean Na-O bond length. Moreover, the present data are in favor of a homogeneous distribution of Na around both oxygen species in the silicate network. Finally, our approach was found to be sensitive enough to investigate the effect of addition of a small quantity of molybdenum oxide (about 1 mol%) on the 17O MAS spectrum, opening new possibilities for investigating the Mo environment in silicate glasses. (authors)

  18. Structural properties of dissolved organic carbon in deep horizons of an arable soil.

    Science.gov (United States)

    Lavaud, A.; Croué, Jp; Berwick, L.; Steffens, M.; Chabbi, A.

    2010-05-01

    The objective of this work is to quantity the DOC that percolates in deep horizons of an arable soil, and to characterize the structural properties of the main fractions. The study was conducted on the long term observatory for environmental research- biogeochemical cycles and biodiversity Lusignan site-France. DOC collected using lysimeter plates inserted to a depth of 105 cm was fractionated into 3 fractions using the two column array of XAD-8 and XAD-4 resins. The HPO (hydrophobic) fraction (i.e. humic substances) isolated from the XAD-8 resin, the TPH (Transphilic) fraction from the XAD-4 resin and the HPI (hydrophilic) fraction which corresponds to the DOC that does not adsorbed onto the two resins under the acid condition used (pH 2). DOM adsorbed onto the resins is recovered with a 75%/25% acetonitrile/water mixture and lyophilized. The hydrophilic fraction is purified according the protocol proposed by Aiken and Leenheer (1993). The isolated fractions were subjected to several characterization tools: UV/Vis, fluorescence EEM, HPSEC/UV/DOC, 13C NMR, 14C dating, FT-IR, pyrolysis, thermochemolysis and MSSV GC/MS. The DOC content ranged from 1 to 2.5 mg / L between winter and the middle of spring and then to 4-5 mg / L in summer time. For all isolated fractions HPSEC analyses indicated the predominance of low molecular structures with a low aromatic character. Fluorescence EEM confirmed the non-humic character of the DOM. 13C-NMR spectra showed that the aromatic character decreased from HPO to TPH, and HPI character. Molecular size follows the same trend. HPI DOM was found to be strongly enriched in carboxyl groups. The 14C concentration of the HPO fraction corresponds to an apparent calibrated age around AD 1500. For the same fraction isolated from the 0 - 30 cm horizon, the measured 14C concentration 131.9 pMC corresponds to that in the atmosphere around AD 1978. Significant input of terpenoid derived organic matter was confirmed in the HPO fraction of DOC

  19. Organization structure as a moderator of the relationship between procedural justice, interactional justice, perceived organizational support, and supervisory trust.

    Science.gov (United States)

    Ambrose, Maureen L; Schminke, Marshall

    2003-04-01

    Organizational justice researchers recognize the important role organization context plays in justice perceptions, yet few studies systematically examine contextual variables. This article examines how 1 aspect of context--organizational structure--affects the relationship between justice perceptions and 2 types of social exchange relationships, organizational and supervisory. The authors suggest that under different structural conditions, procedural and interactional justice will play differentially important roles in determining the quality of organizational social exchange (as evidenced by perceived organizational support [POS]) and supervisory social exchange (as evidenced by supervisory trust). In particular, the authors hypothesized that the relationship between procedural justice and POS would be stronger in mechanistic organizations and that the relationship between interactional justice and supervisory trust would be stronger in organic organizations. The authors' results support these hypotheses.

  20. Structural stability of coprecipitated natural organic matter and ferric iron under reducing conditions

    Science.gov (United States)

    Henneberry, Yumiko K.; Kraus, Tamara E.C.; Nico, Peter S.; Horwath, William R.

    2012-01-01

    The objective was to assess the interaction of Fe coprecipitated with dissolved organic matter (DOM) and its effect on Fe (hydr)oxide crystallinity and DOM retention under abiotic reducing conditions. A Fe-based coagulant was reacted with DOM from an agricultural drain and the resulting precipitate (floc) was exposed to S(-II) and Fe(II). Solution concentrations of Fe(II/III) and DOM were monitored, floc crystallinity was determined using X-ray diffraction, and the composition and distribution of functional groups were assessed using scanning transmission X-ray microscopy (STXM) and near edge X-ray absorption fine structure (NEXAFS) spectroscopy. Results indicate coprecipitation of Fe(III) with DOM forms a non-crystalline floc that withstands crystallization regardless of change in pH, Fe:DOM ratio and type of reductant added. There was no evidence that exposure to reducing conditions led to release of DOM from the floc, indicating that coprecipitation with complex natural DOM in aquatic environments may stabilize Fe (hydr)oxides against crystallization upon reaction with reduced species and lead to long term sequestration of the DOM. STXM analysis identified spatially distinct regions with remarkable functional group purity, contrary to the model of DOM as a relatively uniform complex polymer lacking identifiable organic compounds. Polysaccharide-like OM was strongly and directly correlated with the presence of Fe but showed different Fe binding strength depending on the presence of carboxylic acid functional groups, whereas amide and aromatic functional groups were inversely correlated with Fe content.

  1. Response of Organ Structure and Physiology to Autotetraploidization in Early Development of Energy Willow Salix viminalis.

    Science.gov (United States)

    Dudits, Dénes; Török, Katalin; Cseri, András; Paul, Kenny; Nagy, Anna V; Nagy, Bettina; Sass, László; Ferenc, Györgyi; Vankova, Radomira; Dobrev, Petre; Vass, Imre; Ayaydin, Ferhan

    2016-03-01

    The biomass productivity of the energy willow Salix viminalis as a short-rotation woody crop depends on organ structure and functions that are under the control of genome size. Colchicine treatment of axillary buds resulted in a set of autotetraploid S. viminalis var. Energo genotypes (polyploid Energo [PP-E]; 2n = 4x = 76) with variation in the green pixel-based shoot surface area. In cases where increased shoot biomass was observed, it was primarily derived from larger leaf size and wider stem diameter. Autotetraploidy slowed primary growth and increased shoot diameter (a parameter of secondary growth). The duplicated genome size enlarged bark and wood layers in twigs sampled in the field. The PP-E plants developed wider leaves with thicker midrib and enlarged palisade parenchyma cells. Autotetraploid leaves contained significantly increased amounts of active gibberellins, cytokinins, salicylic acid, and jasmonate compared with diploid individuals. Greater net photosynthetic CO2 uptake was detected in leaves of PP-E plants with increased chlorophyll and carotenoid contents. Improved photosynthetic functions in tetraploids were also shown by more efficient electron transport rates of photosystems I and II. Autotetraploidization increased the biomass of the root system of PP-E plants relative to diploids. Sections of tetraploid roots showed thickening with enlarged cortex cells. Elevated amounts of indole acetic acid, active cytokinins, active gibberellin, and salicylic acid were detected in the root tips of these plants. The presented variation in traits of tetraploid willow genotypes provides a basis to use autopolyploidization as a chromosome engineering technique to alter the organ development of energy plants in order to improve biomass productivity. PMID:26729798

  2. Controlling hierarchical structures in organic solar cell using π- π interactions and their analysis using SANS and PSoXS

    International Nuclear Information System (INIS)

    Controlling the morphology of bulk-heterojunction (BHJ) films in organic photovoltaics (OPVs) is critical in overcoming inherent drawbacks (short exciton diffusion length and low charge mobility) of organic materials and achieving optimal device efficiency. Taking into account the energy conversion process, it is important to understand the hierarchical structure in organic solar cells ranging from molecule-scale and domain-scale to device-scale structure to realize efficient charge separation, transfer, and extraction. However, most of research has so far focused on the domain-level structure such as crystallinity, domain size, and domain orientation because there lacks methods to control hierarchical structures and systematic studies on it. In the present study, we report a new approach to control hierarchical structures in organic solar cells, which was characterized by PSoXS and SANS and their relationship with device performance. We could induce highly anisotropic P3HT crystalline structures (P3HT nanowires), which were grown in a direction of pi-pi stack, facilitating charge transport, through adding poor solvents for P3HT. In addition, the anisotropy of P3HT nanowire was controlled by utilizing additives which have different affinity with PCBM. By employing controlled P3HT nanowires having different anisotropy and following thermal annealing process, we could control the molecular orientation of P3HT at PCBM interfaces (molecular-scale), domain sizes of P3HT and PCBM (domain-scale) and network structures (device-scale). Based on our new method, we could effectively control the hierarchical structures of organic solar cells with an overall view on the relationship between multiscale nanostructure and device performance.

  3. Structural Basis by Which Alternative Splicing Modulates the Organizer Activity of FGF8 in the Brain

    Energy Technology Data Exchange (ETDEWEB)

    Olsen,S.; Li, J.; Eliseenkova, A.; Ibrahimi, O.; Lao, Z.; Zhang, F.; Linhardt, R.; Joyner, A.; Mohammadi, M.

    2006-01-01

    Two of the four human FGF8 splice isoforms, FGF8a and FGF8b, are expressed in the mid-hindbrain region during development. Although the only difference between these isoforms is the presence of an additional 11 amino acids at the N terminus of FGF8b, these isoforms possess remarkably different abilities to pattern the midbrain and anterior hindbrain. To reveal the structural basis by which alternative splicing modulates the organizing activity of FGF8, we solved the crystal structure of FGF8b in complex with the 'c' splice isoform of FGF receptor 2 (FGFR2c). Using surface plasmon resonance (SPR), we also characterized the receptor-binding specificity of FGF8a and FGF8b, the 'b' isoform of FGF17 (FGF17b), and FGF18. The FGF8b-FGFR2c structure shows that alternative splicing permits a single additional contact between phenylalanine 32 (F32) of FGF8b and a hydrophobic groove within Ig domain 3 of the receptor that is also present in FGFR1c, FGFR3c, and FGFR4. Consistent with the structure, mutation of F32 to alanine reduces the affinity of FGF8b toward all these receptors to levels characteristic of FGF8a. More importantly, analysis of the mid-hindbrain patterning ability of the FGF8b{sup F32A} mutant in chick embryos and murine midbrain explants shows that this mutation functionally converts FGF8b to FGF8a. Moreover, our data suggest that the intermediate receptor-binding affinities of FGF17b and FGF18, relative to FGF8a and FGF8b, also account for the distinct patterning abilities of these two ligands. We also show that the mode of FGF8 receptor-binding specificity is distinct from that of other FGFs and provide the first biochemical evidence for a physiological FGF8b-FGFR1c interaction during mid-hindbrain development. Consistent with the indispensable role of FGF8 in embryonic development, we show that the FGF8 mode of receptor binding appeared as early as in nematodes and has been preserved throughout evolution.

  4. Structural basis by which alternative splicing modulates the organizer activity of FGF8 in the brain

    Science.gov (United States)

    Olsen, Shaun K.; Li, James Y.H.; Bromleigh, Carrie; Eliseenkova, Anna V.; Ibrahimi, Omar A.; Lao, Zhimin; Zhang, Fuming; Linhardt, Robert J.; Joyner, Alexandra L.; Mohammadi, Moosa

    2006-01-01

    Two of the four human FGF8 splice isoforms, FGF8a and FGF8b, are expressed in the mid-hindbrain region during development. Although the only difference between these isoforms is the presence of an additional 11 amino acids at the N terminus of FGF8b, these isoforms possess remarkably different abilities to pattern the midbrain and anterior hindbrain. To reveal the structural basis by which alternative splicing modulates the organizing activity of FGF8, we solved the crystal structure of FGF8b in complex with the “c” splice isoform of FGF receptor 2 (FGFR2c). Using surface plasmon resonance (SPR), we also characterized the receptor-binding specificity of FGF8a and FGF8b, the “b” isoform of FGF17 (FGF17b), and FGF18. The FGF8b-FGFR2c structure shows that alternative splicing permits a single additional contact between phenylalanine 32 (F32) of FGF8b and a hydrophobic groove within Ig domain 3 of the receptor that is also present in FGFR1c, FGFR3c, and FGFR4. Consistent with the structure, mutation of F32 to alanine reduces the affinity of FGF8b toward all these receptors to levels characteristic of FGF8a. More importantly, analysis of the mid-hindbrain patterning ability of the FGF8bF32A mutant in chick embryos and murine midbrain explants shows that this mutation functionally converts FGF8b to FGF8a. Moreover, our data suggest that the intermediate receptor-binding affinities of FGF17b and FGF18, relative to FGF8a and FGF8b, also account for the distinct patterning abilities of these two ligands. We also show that the mode of FGF8 receptor-binding specificity is distinct from that of other FGFs and provide the first biochemical evidence for a physiological FGF8b-FGFR1c interaction during mid-hindbrain development. Consistent with the indispensable role of FGF8 in embryonic development, we show that the FGF8 mode of receptor binding appeared as early as in nematodes and has been preserved throughout evolution. PMID:16384934

  5. Linking temperature sensitivity of soil organic matter decomposition to its molecular structure, accessibility, and microbial physiology.

    Science.gov (United States)

    Wagai, Rota; Kishimoto-Mo, Ayaka W; Yonemura, Seiichiro; Shirato, Yasuhito; Hiradate, Syuntaro; Yagasaki, Yasumi

    2013-04-01

    Temperature sensitivity of soil organic matter (SOM) decomposition may have a significant impact on global warming. Enzyme-kinetic hypothesis suggests that decomposition of low-quality substrate (recalcitrant molecular structure) requires higher activation energy and thus has greater temperature sensitivity than that of high-quality, labile substrate. Supporting evidence, however, relies largely on indirect indices of substrate quality. Furthermore, the enzyme-substrate reactions that drive decomposition may be regulated by microbial physiology and/or constrained by protective effects of soil mineral matrix. We thus tested the kinetic hypothesis by directly assessing the carbon molecular structure of low-density fraction (LF) which represents readily accessible, mineral-free SOM pool. Using five mineral soil samples of contrasting SOM concentrations, we conducted 30-days incubations (15, 25, and 35 °C) to measure microbial respiration and quantified easily soluble C as well as microbial biomass C pools before and after the incubations. Carbon structure of LFs (<1.6 and 1.6-1.8 g cm(-3) ) and bulk soil was measured by solid-state (13) C-NMR. Decomposition Q10 was significantly correlated with the abundance of aromatic plus alkyl-C relative to O-alkyl-C groups in LFs but not in bulk soil fraction or with the indirect C quality indices based on microbial respiration or biomass. The warming did not significantly change the concentration of biomass C or the three types of soluble C despite two- to three-fold increase in respiration. Thus, enhanced microbial maintenance respiration (reduced C-use efficiency) especially in the soils rich in recalcitrant LF might lead to the apparent equilibrium between SOM solubilization and microbial C uptake. Our results showed physical fractionation coupled with direct assessment of molecular structure as an effective approach and supported the enzyme-kinetic interpretation of widely observed C quality-temperature relationship for

  6. Structural measurements of polymer-fullerene blend films for organic photovoltaics

    Science.gov (United States)

    Delongchamp, Dean

    2011-03-01

    Organic photovoltaic (OPV) technology has the potential to greatly lower the cost of solar cell fabrication by enabling ink-based deposition of active layers. In bulk heterojunction (BHJ) OPV devices, the power conversion efficiency critically depends on the distribution of the polymer absorber and the fullerene electron acceptor (e.g., the blend morphology). I will describe measurement methods to probe the structure of OPV devices, with a focus on the morphology of the BHJ layer. For example, the vertical distribution of absorber and electron acceptor in BHJ films follows segregation behavior similar to that of miscible polymer blends. The top (air) interface becomes rich in the polymer absorber, whereas the bottom interface composition depends on the substrate surface energy. Thin film transistors fabricated from BHJs can therefore exhibit ambipolar or hole-only transport depending on the dielectric, because of different interfacial segregation. We extend these results to practical photovoltaic devices by comparing BHJs cast upon hole transport layers that have similar work functions but different surface energies. This study includes the application of variable angle spectroscopic ellipsometry (VASE) to BHJ films, and emphasizes the importance of absorber anisotropy and vertical heterogeneity in the optical model. Additional results will describe the nanometer-scale structure in the BHJ interior. The application of solid-state nuclear magnetic resonance (SS-NMR) can reveal details about the segregation of absorber and acceptor in a BHJ film. Nanoscale BHJ morphology information can also be collected using tomographic transmission electron microscopy (TEM). Together these measurements allow us to reveal a detailed picture of BHJ morphology, explain how the morphology originates from materials and processing choices, and relate the morphology to device performance and stability.

  7. Quantitative Structure--Activity Relationship (QSAR) for the Oxidation of Trace Organic Contaminants by Sulfate Radical.

    Science.gov (United States)

    Xiao, Ruiyang; Ye, Tiantian; Wei, Zongsu; Luo, Shuang; Yang, Zhihui; Spinney, Richard

    2015-11-17

    The sulfate radical anion (SO4•–) based oxidation of trace organic contaminants (TrOCs) has recently received great attention due to its high reactivity and low selectivity. In this study, a meta-analysis was conducted to better understand the role of functional groups on the reactivity between SO4•– and TrOCs. The results indicate that compounds in which electron transfer and addition channels dominate tend to exhibit a faster second-order rate constants (kSO4•–) than that of H–atom abstraction, corroborating the SO4•– reactivity and mechanisms observed in the individual studies. Then, a quantitative structure activity relationship (QSAR) model was developed using a sequential approach with constitutional, geometrical, electrostatic, and quantum chemical descriptors. Two descriptors, ELUMO and EHOMO energy gap (ELUMO–EHOMO) and the ratio of oxygen atoms to carbon atoms (#O:C), were found to mechanistically and statistically affect kSO4•– to a great extent with the standardized QSAR model: ln kSO4•– = 26.8–3.97 × #O:C – 0.746 × (ELUMO–EHOMO). In addition, the correlation analysis indicates that there is no dominant reaction channel for SO4•– reactions with various structurally diverse compounds. Our QSAR model provides a robust predictive tool for estimating emerging micropollutants removal using SO4•– during wastewater treatment processes. PMID:26451961

  8. Comparative organization of the claustrum: what does structure tell us about function?

    Directory of Open Access Journals (Sweden)

    Joan S Baizer

    2014-07-01

    Full Text Available The claustrum is a subcortical nucleus present in all placental mammals. Many anatomical studies have shown that its inputs are predominantly from the cerebral cortex and its outputs are back to the cortex. This connectivity thus suggests that the claustrum serves to amplify or facilitate information processing in the cerebral cortex. The size and the complexity of the cerebral cortex change dramatically over evolution. Rodents are lissencephalic, with few cortical areas, while many primates have a greatly expanded cortex and many cortical areas. This evolutionary diversity in the cerebral cortex raises several questions about the claustrum. Does its volume expand in coordination with the expansion of cortex and does it acquire new functions related to the new cortical functions? We have examined the organization of the claustrum in animals with large brains, including great apes and cetaceans. Our data suggest that the claustrum is not always a continuous structure. In monkeys and gorillas there are a few isolated islands of cells near the main body of the nucleus. In cetaceans, however, there are many isolated cell islands. These data suggest constraints on the possible function of the claustrum. Some authors propose that the claustrum has a more global role in perception or consciousness that requires intraclaustral integration of information. These theories postulate mechanisms like gap junctions between claustral cells or a syncytium to mediate intraclaustral processing. The presence of discontinuities in the structure of the claustrum, present but minimal in primates, but dramatically clear in cetaceans, argues against the proposed mechanisms of intraclaustral processing of information. The best interpretation of function, then, is that each functional subdivision of the claustrum simply contributes to the function of its cortical partner.

  9. Analysis of self-organized In(Ga)As quantum structures with the scanning transmission electron microscope

    International Nuclear Information System (INIS)

    Aim of this thesis was to apply the analytical methods of the scanning transmission electron microscopy to the study of self-organized In(Ga)As quantum structures. With the imaging methods Z contrast and bright field (position resolutions in the subnanometer range) and especially with the possibilities of the quantitative chemical EELS analysis of the scanning transmission electron microscope (STEM) fundamental questions concerning morphology and chemical properties of self-organized quantum structures should be answered. By the high position resolution of the STEM among others essentail morphological and structural parameters in the growth behaviour of ''dot in a well'' (DWell) structures and of vertically correlated quantum dots (QDs) could be analyzed. For the optimization of DWell structures samples were studied, the nominal InAs-QD growth position was directedly varied within the embedding InGaAs quantum wells. The STEM offers in connection with the EELS method a large potential for the chemical analysis of quantum structures. Studied was a sample series of self-organized InGaAs/GaAs structures on GaAs substrate, the stress of which was changed by varying the Ga content of the INGaAs material between 2.4 % and 4.3 %

  10. Bimetallic nanoalloys in heterogeneous catalysis of industrially important reactions: synergistic effects and structural organization of active components

    International Nuclear Information System (INIS)

    The review is concerned with correlations between the synergistic effects and structural organization of the surface of bimetallic alloys that are used as active components of catalysts for selective hydrogenation of organic compounds and for CO oxidation in hydrogen-rich mixtures. Studies on the preparation of novel highly efficient catalysts using modern theoretical approaches, computer-assisted molecular design and original synthetic procedures are considered. It is shown that introduction of the second metal into the monometallic catalyst and subsequent formation of alloy particles with modified structure of the surface and near-surface layers leads to nonadditive enhancement of catalytic activity and/or selectivity. The bibliography includes 203 references

  11. THE INFLUENCE OF THE INTEGRATED MODEL OF SOCIAL STRATIFICATION STRUCTURE ON THE PUBLIC PARTICIPATING NON-PROFIT ORGANIZATIONS

    Directory of Open Access Journals (Sweden)

    Yu-Tien Huang

    2013-01-01

    Full Text Available The main body of social stratification structure in Taiwan is transformed with social mobility. By transforming the social stratification structure, the function of non-profit organizations is operating steadily. How does people’s awareness of social strata directly or indirectly influence the operation of non-profit organizations? How do non-profit organizations and governments respond to the transformation of social stratum compositions? And how promotion and policy marketing could guide the general public to be attentive and participate in the operations of non-profit organizations? These questions require in-depth investigation. This study bases on the experiments and concepts of fairness measurement in information integration theory to comprehend the integrated model of social stratification in the public. By means of analyzing the awareness and orientation of the public to the constitution of social stratification which lead the public to identify themselves with the visions of non-profit organizations and the motion of participating non-profit matters to provide the interrelated recommendations of proceeding non-profit matters to non-profit organizations and the government. Comparing the cognitive algebraic functions of input information and outcome information of various groups in the social strata, the only difference is that if the input information is education background and the outcome information profession prestige. Empirically, non-profit organizations promoting and encouraging people to engage in occupational aid related activities could find different methods available.

  12. Polymer-ultrathin graphite sheet-polymer composite structured flexible nonvolatile bistable organic memory devices

    Energy Technology Data Exchange (ETDEWEB)

    Son, Dong Ick; Park, Dong Hee; Choi, Won Kook [Future Convergence Research Division, Korea Institute of Science and Technology, Cheongryang, PO Box 131, Seoul 130-650 (Korea, Republic of); Shim, Jae Ho; Jung, Jae Hun; Kim, Tae Whan [Division of Electronics and Computer Engineering, Hanyang University, 17 Haengdang dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Lee, Jung Min; Park, Won Il, E-mail: wkchoi@kist.re.kr [Department of Materials Science and Engineering, Hanyang University, 17 Haengdang dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of)

    2011-07-22

    We present data, which were obtained before bending and after bending, for the electrical bistabilities, memory stabilities, and memory mechanisms of three-layer structured flexible bistable organic memory (BOM) devices, which were fabricated utilizing the ultrathin graphite sheets (UGS) sandwiched between insulating poly(methylmethacrylate) (PMMA) polymer layers. The UGS were formed by transferring UGS (about 30 layers) and using a simple spin-coating technique. Transmission electron microscopy (TEM) measurements were performed to investigate the microstructural properties of the PMMA/UGS/PMMA films. Current-voltage (I-V) measurements were carried out to investigate the electrical properties of the BOM devices containing the UGS embedded in the PMMA polymer. Current-time (I-t) and current-cycle measurements under flat and bent conditions were performed to investigate the memory stabilities of the BOM devices. The memory characteristics of the BOM maintained similar device efficiencies after bending and were stable during repeated bendings of the BOM devices. The mechanisms for these characteristics of the fabricated BOM are described on the basis of the I-V results.

  13. Efficient Hybrid White Organic Light-Emitting Diodes for Application of Triplet Harvesting with Simple Structure

    CERN Document Server

    Hwang, Kyo Min; Lee, Sungkyu; Yoo, Han Kyu; Baek, Hyun Jung; Kim, Jwajin; Yoon, Seung Soo; Kim, Young Kwan

    2016-01-01

    In this study, we fabricated hybrid white organic light-emitting diodes (WOLEDs) based on triplet harvesting with simple structure. All the hole transporting material and host in emitting layer (EML) of devices were utilized with same material by using N,N'-di-1-naphthalenyl-N,N'-diphenyl-[1,1':4',1":4",1"'-quaterphenyl]-4,4"'-diamine (4P-NPD) which were known to be blue fluorescent material. Simple hybrid WOLEDs were fabricated three color with blue fluorescent and green, red phosphorescent materials. We was investigated the effect of triplet harvesting (TH) by exciton generation zone on simple hybrid WOLEDs. Characteristic of simple hybrid WOLEDs were dominant hole mobility, therefore exciton generation zone was expected in EML. Additionally, we was optimization thickness of hole transporting layer and electron transporting layer was fabricated a simple hybrid WOLEDs. Simple hybrid WOLED exhibits maximum luminous efficiency of 29.3 cd/A and maximum external quantum efficiency of 11.2%. Commission Internatio...

  14. Self-organizing numerical models of transient processes in water supply hydraulic structures of energy industries

    Directory of Open Access Journals (Sweden)

    N.V. Arefyev

    2013-10-01

    Full Text Available Currently, there is an increase of diversity in the design of complex hydraulic structures. Thus there is a need to establish adequate mathematical models and software with complete description of processes. These models should be focused on certain classes of problems, which statements may change during the simulation. So, in our opinion, so-called self-organizing simulation models are perspective, they adapt to changes in the operating practice of the objects that require rapid adjustments in the boundary conditions and the field of simulation. Results of development of self-adapting complexes of numerical models, permitting calculation of complex water passageway systems with varying flow regime on separate parts (discharge; movement on the dry bottom, provided hydraulic head in free-flow downstream tunnel etc.. Presented system traces the movement of modeling area boundaries (when filling and dumping water passage sections and chooses the appropriate boundary condition with changing flow regime on the border of modelling area of the flow (free-flowing weir – drowned weir.Given results of numerical simulation of real systems make it possible to consider proposed approach as efficient.

  15. Altered modular organization of structural cortical networks in children with autism.

    Directory of Open Access Journals (Sweden)

    Feng Shi

    Full Text Available Autism is a complex developmental disability that characterized by deficits in social interaction, language skills, repetitive stereotyped behaviors and restricted interests. Although great heterogeneity exists, previous findings suggest that autism has atypical brain connectivity patterns and disrupted small-world network properties. However, the organizational alterations in the autistic brain network are still poorly understood. We explored possible organizational alterations of 49 autistic children and 51 typically developing controls, by investigating their brain network metrics that are constructed upon cortical thickness correlations. Three modules were identified in controls, including cortical regions associated with brain functions of executive strategic, spatial/auditory/visual, and self-reference/episodic memory. There are also three modules found in autistic children with similar patterns. Compared with controls, autism demonstrates significantly reduced gross network modularity, and a larger number of inter-module connections. However, the autistic brain network demonstrates increased intra- and inter-module connectivity in brain regions including middle frontal gyrus, inferior parietal gyrus, and cingulate, suggesting one underlying compensatory mechanism associated with brain functions of self-reference and episodic memory. Results also show that there is increased correlation strength between regions inside frontal lobe, as well as impaired correlation strength between frontotemporal and frontoparietal regions. This alteration of correlation strength may contribute to the organization alteration of network structures in autistic brains.

  16. Structured Interview of Personality Organization (STIPO): preliminary psychometrics in a clinical sample.

    Science.gov (United States)

    Stern, Barry L; Caligor, Eve; Clarkin, John F; Critchfield, Kenneth L; Horz, Susanne; MacCornack, Verna; Lenzenweger, Mark F; Kernberg, Otto F

    2010-01-01

    In this article, we describe the development and preliminary psychometric properties of the Structured Interview of Personality Organization (STIPO), a semistructured interview designed for the dimensional assessment of identity, primitive defenses, and reality testing, the three primary content domains in the model of personality health and disorder elaborated by Kernberg (1984; Kernberg & Caligor, 2005). Results of this investigation, conducted in a clinical sample representing a broad range of personality pathology, indicate that identity and primitive defenses as operationalized in the STIPO are internally consistent and that interrater reliability for all 3 content domains is adequate. Validity findings suggest that the assessment of one's sense of self and significant others (Identity) is predictive of measures of positive and negative affect, whereas the maladaptive ways in which the subject uses his or her objects for purposes of regulating one's self experience (Primitive Defenses) is predictive of measures of aggression and personality disorder traits associated with cluster B personality disorders. We discuss implications of these findings in terms of the theory-driven and trait-based assessment of personality pathology. PMID:20013454

  17. Structure and logical organization of current studies in track and field sports

    Directory of Open Access Journals (Sweden)

    Bobrovnik V.I.

    2014-02-01

    Full Text Available Purpose: to develop a system of assessment and prediction of technical skill athletes-athletes. Material : the study involved 450 athletes qualifications. Results : in the process of preparing members of the Ukrainian national team implemented a system of assessment of mental state. It includes: a set of informative indicators biomechanical laws and their changes; biomechanical model of motor actions; technology operational biomechanical modeling, changes in the functional state of the viscoelastic properties of skeletal muscle vestibulomotornoy system and speed- force readiness, evaluation and prediction of physical condition of athletes qualified. And complex pedagogical tests and scorecards. For the evaluation of the functional state of the autonomic nervous, cardiovascular system, external respiration system by analyzing the electrocardiogram, heart rate variability, the definition of autonomic balance, state of the myocardium, cardiac arrhythmias, spirometric studies, system performance evaluation of the athlete in extreme conditions by identifying the type and properties of temperament, level of personal anxiety and psychological evaluation reliability athletes. Conclusions : the structure and logical organization of modern studies of different primary focus, based on the assessment of technical skills, physical fitness, functional and mental state of highly skilled athletes.

  18. A genome-wide survey of switchgrass genome structure and organization.

    Directory of Open Access Journals (Sweden)

    Manoj K Sharma

    Full Text Available The perennial grass, switchgrass (Panicum virgatum L., is a promising bioenergy crop and the target of whole genome sequencing. We constructed two bacterial artificial chromosome (BAC libraries from the AP13 clone of switchgrass to gain insight into the genome structure and organization, initiate functional and comparative genomic studies, and assist with genome assembly. Together representing 16 haploid genome equivalents of switchgrass, each library comprises 101,376 clones with average insert sizes of 144 (HindIII-generated and 110 kb (BstYI-generated. A total of 330,297 high quality BAC-end sequences (BES were generated, accounting for 263.2 Mbp (16.4% of the switchgrass genome. Analysis of the BES identified 279,099 known repetitive elements, >50,000 SSRs, and 2,528 novel repeat elements, named switchgrass repetitive elements (SREs. Comparative mapping of 47 full-length BAC sequences and 330K BES revealed high levels of synteny with the grass genomes sorghum, rice, maize, and Brachypodium. Our data indicate that the sorghum genome has retained larger microsyntenous regions with switchgrass besides high gene order conservation with rice. The resources generated in this effort will be useful for a broad range of applications.

  19. Structural organization of large and very-large scales in turbulent pipe flow simulation

    Science.gov (United States)

    Baltzer, Jon; Adrian, Ronald; Wu, Xiaohua

    2012-11-01

    The physical structures of velocity are examined in a recent DNS of fully developed incompressible turbulent pipe flow at ReD = 24 580 (R+ = 684 . 8) with a periodic domain length of 30 pipe radii R (Wu, Baltzer, & Adrian, J. Fluid Mech., 2012). In this simulation, the long motions of negative velocity fluctuation correspond to large fractions of energy present at very long streamwise wavelengths (>= 3 R). We study how long motions are composed of smaller motions. We characterize the spatial arrangements of very large scale motions (VLSMs) and find that they possess dominant helix angles (azimuthal inclinations relative to streamwise) that are revealed by 2D and 3D two-point spatial correlations of velocity. The correlations also reveal that the shorter, large scale motions (LSMs) that concatenate to comprise the VLSMs are themselves more streamwise aligned. We show that the largest VLSMs possess a form similar to roll cells and that they appear to play an important role in organizing the flow, while smaller scales of motion are necessary to create the strong streaks of velocity fluctuation that characterize the flow. Supported by NSF Award CBET-0933848.

  20. C{sub 60}-dyad aggregates: Self-organized structures in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Guskova, O. A., E-mail: guskova@ipfdd.de, E-mail: s.raovaranasi@uq.edu.au; Varanasi, S. R., E-mail: guskova@ipfdd.de, E-mail: s.raovaranasi@uq.edu.au [Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Straße 6, Dresden D-01069 (Germany); Sommer, J.-U. [Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Straße 6, Dresden D-01069 (Germany); Institut für Theoretische Physik, Technische Universität Dresden, Zellescher Weg 17, Dresden D-01069 (Germany)

    2014-10-14

    Extensive full-atomistic molecular dynamics simulations are performed to study the self-organization of C{sub 60}-fullerene dyad molecules in water, namely phenyl-C{sub 61}-butyric acid methyl ester and fulleropyrrolidines, which have two elements of ordering, the hydrophobic fullerene cage and the hydrophilic/ionic group. While pristine fullerene or phenyl-C{sub 61}-butyric acid methyl ester forms spherical droplets in order to minimize the surface tension, the amphiphilic nature of charged solute molecules leads to the formation of supramolecular assemblies having cylindrical shape driven by charge repulsion between the ionic groups located on the surface of the aggregates. We show that formation of non-spherical micelles is the geometrical consequence if the fullerene derivatives are considered as surfactants where the ionized groups are only hydrophilic unit. The agglomeration behavior of fullerenes is evaluated by determining sizes of the clusters, solvent accessible surface areas, and shape parameters. By changing the size of the counterions from chloride over iodide to perchlorate we find a thickening of the cylinder-like structures which can be explained by stronger condensation of larger ions and thus partial screening of the charge repulsion on the cluster surface. The reason for the size dependence of counterion condensation is the formation of a stronger hydration shell in case of small ions which in turn are repelled from the fullerene aggregates. Simulations are also in good agreement with the experimentally observed morphologies of decorated C{sub 60}-nanoparticles.

  1. Ab Initio Assessment of the Structural and Optoelectronic Properties of Organic-ZnO Nanoclusters.

    Science.gov (United States)

    Kumar, Pushpendra; Pal, Suman Kalyan

    2015-10-01

    Structural, electronic, and optical properties of a new coumarin dye, zinc oxide (ZnO) nanoclusters of varying sizes, and their complexes have been investigated using density functional theory (DFT). The band gap of oxide nanoclusters varies with size validating quantum confinement effect in small particles. Energy level diagrams of dye, ZnO nanoclusters, and redox electrolyte are in favor of efficient electron injection from dye to nanocluster and regeneration of the ionized dye. The adsorption of the organic dye to nanocluster is tested for anchoring through three different functional groups (cyano, carbonyl, and hydroxyl) of the dye. We have compared simulated absorption spectra of the dye, nanoclusters, and dye functionalized nanoclusters and discussed the matching with the solar irradiance spectrum. A strong new band appeared in the low energy side of the absorption spectra for dye adsorbed nanoclusters. Frontier molecular orbital calculations reveal that the first absorption band of dye-ZnO complexes is charge transfer (CT) in character. Excitation of this band leads to direct electron transfer to the conduction band (CB) of the nanocluster, making dye-ZnO complexes suitable for type II DSSCs as well. PMID:26348781

  2. How habitat-modifying organisms structure the food web of two coastal ecosystems.

    Science.gov (United States)

    van der Zee, Els M; Angelini, Christine; Govers, Laura L; Christianen, Marjolijn J A; Altieri, Andrew H; van der Reijden, Karin J; Silliman, Brian R; van de Koppel, Johan; van der Geest, Matthijs; van Gils, Jan A; van der Veer, Henk W; Piersma, Theunis; de Ruiter, Peter C; Olff, Han; van der Heide, Tjisse

    2016-03-16

    The diversity and structure of ecosystems has been found to depend both on trophic interactions in food webs and on other species interactions such as habitat modification and mutualism that form non-trophic interaction networks. However, quantification of the dependencies between these two main interaction networks has remained elusive. In this study, we assessed how habitat-modifying organisms affect basic food web properties by conducting in-depth empirical investigations of two ecosystems: North American temperate fringing marshes and West African tropical seagrass meadows. Results reveal that habitat-modifying species, through non-trophic facilitation rather than their trophic role, enhance species richness across multiple trophic levels, increase the number of interactions per species (link density), but decrease the realized fraction of all possible links within the food web (connectance). Compared to the trophic role of the most highly connected species, we found this non-trophic effects to be more important for species richness and of more or similar importance for link density and connectance. Our findings demonstrate that food webs can be fundamentally shaped by interactions outside the trophic network, yet intrinsic to the species participating in it. Better integration of non-trophic interactions in food web analyses may therefore strongly contribute to their explanatory and predictive capacity. PMID:26962135

  3. Molecular organization of the nanoscale surface structures of the dragonfly Hemianax papuensis wing epicuticle.

    Directory of Open Access Journals (Sweden)

    Elena P Ivanova

    Full Text Available The molecular organization of the epicuticle (the outermost layer of insect wings is vital in the formation of the nanoscale surface patterns that are responsible for bestowing remarkable functional properties. Using a combination of spectroscopic and chromatographic techniques, including Synchrotron-sourced Fourier-transform infrared microspectroscopy (FTIR, x-ray photoelectron spectroscopy (XPS depth profiling and gas chromatography-mass spectrometry (GCMS, we have identified the chemical components that constitute the nanoscale structures on the surface of the wings of the dragonfly, Hemianax papuensis. The major components were identified to be fatty acids, predominantly hexadecanoic acid and octadecanoic acid, and n-alkanes with even numbered carbon chains ranging from C14 to C30. The data obtained from XPS depth profiling, in conjunction with that obtained from GCMS analyses, enabled the location of particular classes of compounds to different regions within the epicuticle. Hexadecanoic acid was found to be a major component of the outer region of the epicuticle, which forms the surface nanostructures, and was also detected in deeper layers along with octadecanoic acid. Aliphatic compounds were detected throughout the epicuticle, and these appeared to form a third discrete layer that was separate from both the inner and outer epicuticles, which has never previously been reported.

  4. Research Update: Mechanical properties of metal-organic frameworks – Influence of structure and chemical bonding

    Directory of Open Access Journals (Sweden)

    Wei Li

    2014-12-01

    Full Text Available Metal-organic frameworks (MOFs, a young family of functional materials, have been attracting considerable attention from the chemistry, materials science, and physics communities. In the light of their potential applications in industry and technology, the fundamental mechanical properties of MOFs, which are of critical importance for manufacturing, processing, and performance, need to be addressed and understood. It has been widely accepted that the framework topology, which describes the overall connectivity pattern of the MOF building units, is of vital importance for the mechanical properties. However, recent advances in the area of MOF mechanics reveal that chemistry plays a major role as well. From the viewpoint of materials science, a deep understanding of the influence of chemical effects on MOF mechanics is not only highly desirable for the development of novel functional materials with targeted mechanical response, but also for a better understanding of important properties such as structural flexibility and framework breathing. The present work discusses the intrinsic connection between chemical effects and the mechanical behavior of MOFs through a number of prototypical examples.

  5. Organic light emitting diodes (OLEDS) and OLED-based structurally integrated optical sensors

    International Nuclear Information System (INIS)

    doping was also discussed. Stretched exponential analysis also generates calibration curves with higher sensitivity, which is preferred from the operational point of view. The work of enhanced integration was shown in chapter 7 with a polymer photodetector, which enables the preferred operation mode, decay time measurement, due to fast reponse (<20 μs). Device thickness was enlarged for maximum absorption of the PL, which was realized by slow spincoating rate and shorter spincoating time. Film prepared this way shows more crystalline order by Raman spectra, probably due to slow evaporation. This also ensures charge transport is not affected even with a thick film as indicated in the response time. Combination of OLEDs and polymer photodetectors present opportunities for solution processed all-organic sensors, which enables cheap processing at large scale. Future development can focus on monolithically integration of OLEDs and organic photodetectors (OPD) on the same substrate at a small scale, which could be enabled by inkjet printing. As OLED and OPD technologies continue to advance, small-sized, flexible and all-organic structurally integrated sensor platforms will become true in the near future.

  6. Organic light emitting diodes (OLEDS) and OLED-based structurally integrated optical sensors

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Yuankun [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    rate due to microheterogeneity. Effect of TiO2 doping was also discussed. Stretched exponential analysis also generates calibration curves with higher sensitivity, which is preferred from the operational point of view. The work of enhanced integration was shown in chapter 7 with a polymer photodetector, which enables the preferred operation mode, decay time measurement, due to fast reponse (<20 μs). Device thickness was enlarged for maximum absorption of the PL, which was realized by slow spincoating rate and shorter spincoating time. Film prepared this way shows more crystalline order by Raman spectra, probably due to slow evaporation. This also ensures charge transport is not affected even with a thick film as indicated in the response time. Combination of OLEDs and polymer photodetectors present opportunities for solution processed all-organic sensors, which enables cheap processing at large scale. Future development can focus on monolithically integration of OLEDs and organic photodetectors (OPD) on the same substrate at a small scale, which could be enabled by inkjet printing. As OLED and OPD technologies continue to advance, small-sized, flexible and all-organic structurally integrated sensor platforms will become true in the near future.

  7. Organic light emitting diodes (OLEDS) and OLED-based structurally integrated optical sensors

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Yuankun

    2010-05-16

    microheterogeneity. Effect of TiO{sub 2} doping was also discussed. Stretched exponential analysis also generates calibration curves with higher sensitivity, which is preferred from the operational point of view. The work of enhanced integration was shown in chapter 7 with a polymer photodetector, which enables the preferred operation mode, decay time measurement, due to fast reponse (<20 {mu}s). Device thickness was enlarged for maximum absorption of the PL, which was realized by slow spincoating rate and shorter spincoating time. Film prepared this way shows more crystalline order by Raman spectra, probably due to slow evaporation. This also ensures charge transport is not affected even with a thick film as indicated in the response time. Combination of OLEDs and polymer photodetectors present opportunities for solution processed all-organic sensors, which enables cheap processing at large scale. Future development can focus on monolithically integration of OLEDs and organic photodetectors (OPD) on the same substrate at a small scale, which could be enabled by inkjet printing. As OLED and OPD technologies continue to advance, small-sized, flexible and all-organic structurally integrated sensor platforms will become true in the near future.

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

    International Nuclear Information System (INIS)

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

  9. Obligation for the reporting of events and internal organization structure for information of the authorities by the utility

    International Nuclear Information System (INIS)

    The obligation of the utilities for the reporting of events to the authorities responsible for nuclear regulation and safety of the public is shown in this report. As an example the nuclear power plants of PreussenElektra Brokdorf and Stade are taken. The internal organization structure and the ways of communication to the authorities are discribed. Furthermore, the outlook and structure of the report which is used for alarm and information of the authorities is shown. (orig.)

  10. The Impact of Structural Empowerment on Organizational Citizenship Behavior-Organization and Job Performance: A Mediating Role of Burnout

    OpenAIRE

    Hina Jaffery; Hassan Farooq

    2015-01-01

    The banking sector employees are usually exposed to potential job burnout which impacts their employee performance. This study examined the impact of structural empowerment on organizational citizenship behavior-organization (henceforth, OCBO) and job performance and further examined the mediating effect of job burnout in the relationships of structural empowerment, OCBO and job performance. In this study, data from 282 employees was taken from four banks: both public and private sectors. Two...

  11. Patterns of capital structure and dividend policy in Pakistani corporate sector and their impact on organization performance

    OpenAIRE

    Hunjra, Ahmed Imran; Bilal, Muhammad; Shafi, Haroon; Ullah, Ikram; Rehman, Kashif-Ur-

    2010-01-01

    The purpose of this study is to determine the patterns of capital structure decisions and dividend policy as well as their level of application in Pakistani corporate sector and also to check the impact of capital structure and dividend policy on organization performance. A total of ninety one questionnaires were distributed in different companies but seventy three filled were received and sixty one were processed for the analysis. The potential respondents were finance executives and financi...

  12. Influence of commercially available polyimide and formation conditions on the performance and structure of asymmetric polyimide organic solvent nanofiltration membranes

    OpenAIRE

    Lopes, Mafalda Pessoa

    2009-01-01

    This work covers experimental and theoretical research related to the impact of the polymer structure of commercially available polyimide and polyetherimides as well as the formation conditions on the performance and structure of polyimide Organic Solvent Nanofiltration membranes. The influence in some membrane formation parameters such as polymer choice, solvent system composition, chemical crosslinking, solubility, humidity and coagulation bath temperature on the performance of PI membra...

  13. Associations between soil bacterial community structure and nutrient cycling functions in long-term organic farm soils following cover crop and organic fertilizer amendment.

    Science.gov (United States)

    Fernandez, Adria L; Sheaffer, Craig C; Wyse, Donald L; Staley, Christopher; Gould, Trevor J; Sadowsky, Michael J

    2016-10-01

    Agricultural management practices can produce changes in soil microbial populations whose functions are crucial to crop production and may be detectable using high-throughput sequencing of bacterial 16S rRNA. To apply sequencing-derived bacterial community structure data to on-farm decision-making will require a better understanding of the complex associations between soil microbial community structure and soil function. Here 16S rRNA sequencing was used to profile soil bacterial communities following application of cover crops and organic fertilizer treatments in certified organic field cropping systems. Amendment treatments were hairy vetch (Vicia villosa), winter rye (Secale cereale), oilseed radish (Raphanus sativus), buckwheat (Fagopyrum esculentum), beef manure, pelleted poultry manure, Sustane(®) 8-2-4, and a no-amendment control. Enzyme activities, net N mineralization, soil respiration, and soil physicochemical properties including nutrient levels, organic matter (OM) and pH were measured. Relationships between these functional and physicochemical parameters and soil bacterial community structure were assessed using multivariate methods including redundancy analysis, discriminant analysis, and Bayesian inference. Several cover crops and fertilizers affected soil functions including N-acetyl-β-d-glucosaminidase and β-glucosidase activity. Effects, however, were not consistent across locations and sampling timepoints. Correlations were observed among functional parameters and relative abundances of individual bacterial families and phyla. Bayesian analysis inferred no directional relationships between functional activities, bacterial families, and physicochemical parameters. Soil functional profiles were more strongly predicted by location than by treatment, and differences were largely explained by soil physicochemical parameters. Composition of soil bacterial communities was predictive of soil functional profiles. Differences in soil function were

  14. Associations between soil bacterial community structure and nutrient cycling functions in long-term organic farm soils following cover crop and organic fertilizer amendment.

    Science.gov (United States)

    Fernandez, Adria L; Sheaffer, Craig C; Wyse, Donald L; Staley, Christopher; Gould, Trevor J; Sadowsky, Michael J

    2016-10-01

    Agricultural management practices can produce changes in soil microbial populations whose functions are crucial to crop production and may be detectable using high-throughput sequencing of bacterial 16S rRNA. To apply sequencing-derived bacterial community structure data to on-farm decision-making will require a better understanding of the complex associations between soil microbial community structure and soil function. Here 16S rRNA sequencing was used to profile soil bacterial communities following application of cover crops and organic fertilizer treatments in certified organic field cropping systems. Amendment treatments were hairy vetch (Vicia villosa), winter rye (Secale cereale), oilseed radish (Raphanus sativus), buckwheat (Fagopyrum esculentum), beef manure, pelleted poultry manure, Sustane(®) 8-2-4, and a no-amendment control. Enzyme activities, net N mineralization, soil respiration, and soil physicochemical properties including nutrient levels, organic matter (OM) and pH were measured. Relationships between these functional and physicochemical parameters and soil bacterial community structure were assessed using multivariate methods including redundancy analysis, discriminant analysis, and Bayesian inference. Several cover crops and fertilizers affected soil functions including N-acetyl-β-d-glucosaminidase and β-glucosidase activity. Effects, however, were not consistent across locations and sampling timepoints. Correlations were observed among functional parameters and relative abundances of individual bacterial families and phyla. Bayesian analysis inferred no directional relationships between functional activities, bacterial families, and physicochemical parameters. Soil functional profiles were more strongly predicted by location than by treatment, and differences were largely explained by soil physicochemical parameters. Composition of soil bacterial communities was predictive of soil functional profiles. Differences in soil function were

  15. A First-Principles Study on the Structural and Electronic Properties of Sn-Based Organic-Inorganic Halide Perovskites

    Science.gov (United States)

    Ma, Zi-Qian; Pan, Hui; Wong, Pak Kin

    2016-08-01

    Organic-inorganic halide perovskites have attracted increasing interest on solar-energy harvesting because of their outstanding electronic properties. In this work, we systematically investigate the structural and electronic properties of Sn-based hybrid perovskites MASnX3 and FASnX3 (X = I, Br) based on density-functional-theory calculations. We find that their electronic properties strongly depend on the organic molecules, halide atoms, and structures. We show that there is a general rule to predict the band gap of the Sn-based hybrid perovskite: its band gap increases as the size of halide atom decreases as well as that of organic molecule increase. The band gap of high temperature phase (cubic structure) is smaller than that of low temperature phase (orthorhombic structure). The band gap of tetragonal structure (medium-temperature phase) may be larger or smaller than that of cubic phase, depending on the orientation of the molecule. Tunable band gap within a range of 0.73-1.53 eV can be achieved by choosing halide atom and organic molecule, and controlling structure. We further show that carrier effective mass also reduces as the size of halide atom increases and that of molecule decreases. By comparing with Pb-based hybrid perovskites, the Sn-based systems show enhanced visible-light absorption and carrier mobility due to narrowed band gap and reduced carrier effective mass. These Sn-based organic-inorganic halide perovskites may find applications in solar energy harvesting with improved performance.

  16. A First-Principles Study on the Structural and Electronic Properties of Sn-Based Organic-Inorganic Halide Perovskites

    Science.gov (United States)

    Ma, Zi-Qian; Pan, Hui; Wong, Pak Kin

    2016-11-01

    Organic-inorganic halide perovskites have attracted increasing interest on solar-energy harvesting because of their outstanding electronic properties. In this work, we systematically investigate the structural and electronic properties of Sn-based hybrid perovskites MASnX3 and FASnX3 (X = I, Br) based on density-functional-theory calculations. We find that their electronic properties strongly depend on the organic molecules, halide atoms, and structures. We show that there is a general rule to predict the band gap of the Sn-based hybrid perovskite: its band gap increases as the size of halide atom decreases as well as that of organic molecule increase. The band gap of high temperature phase (cubic structure) is smaller than that of low temperature phase (orthorhombic structure). The band gap of tetragonal structure (medium-temperature phase) may be larger or smaller than that of cubic phase, depending on the orientation of the molecule. Tunable band gap within a range of 0.73-1.53 eV can be achieved by choosing halide atom and organic molecule, and controlling structure. We further show that carrier effective mass also reduces as the size of halide atom increases and that of molecule decreases. By comparing with Pb-based hybrid perovskites, the Sn-based systems show enhanced visible-light absorption and carrier mobility due to narrowed band gap and reduced carrier effective mass. These Sn-based organic-inorganic halide perovskites may find applications in solar energy harvesting with improved performance.

  17. Polar organic compounds in pore waters of the Chesapeake Bay impact structure, Eyreville core hole: Character of the dissolved organic carbon and comparison with drilling fluids

    Science.gov (United States)

    Rostad, C.E.; Sanford, W.E.

    2009-01-01

    Pore waters from the Chesapeake Bay impact structure cores recovered at Eyreville Farm, Northampton County, Virginia, were analyzed to characterize the dissolved organic carbon. After squeezing or centrifuging, a small volume of pore water, 100 ??L, was taken for analysis by electrospray ionization-mass spectrometry. Porewater samples were analyzed directly without filtration or fractionation, in positive and negative mode, for polar organic compounds. Spectra in both modes were dominated by low-molecular-weight ions. Negative mode had clusters of ions differing by -60 daltons, possibly due to increasing concentrations of inorganic salts. The numberaverage molecular weight and weight-average molecular weight values for the pore waters from the Chesapeake Bay impact structure are higher than those reported for other aquatic sources of natural dissolved organic carbon as determined by electrospray ionization-mass spectrometry. In order to address the question of whether drilling mud fluids may have contaminated the pore waters during sample collection, spectra from the pore waters were compared to spectra from drilling mud fluids. Ions indicative of drilling mud fluids were not found in spectra from the pore waters, indicating there was no detectable contamination, and highlighting the usefulness of this analytical technique for detecting potential contamination during sample collection. ?? 2009 The Geological Society of America.

  18. Drift-Diffusion Modeling of the Effects of Structural Disorder and Carrier Mobility on the Performance of Organic Photovoltaic Devices

    Science.gov (United States)

    Finck, Benjamin Y.; Schwartz, Benjamin J.

    2015-09-01

    We probe the effects of structural disorder on the performance of organic photovoltaic (OPV) devices via drift-diffusion modeling. We utilize ensembles of spatially disordered one-dimensional mobility profiles to approximate the three-dimensional structural disorder present in actual devices. Each replica in our ensemble approximates one high-conductivity pathway through the three-dimensional network(s) present in a polymer-based bulk heterojunction solar cell, so that the ensemble-averaged behavior provides a good approximation to a full three-dimensional structurally disordered device. Our calculations show that the short-circuit current, fill factor, and power conversion efficiency of simulated devices are all negatively impacted by the inclusion of structural disorder, but that the open-circuit voltage is nearly impervious to structural defects. This is in contrast to energetic disorder, where previous studies found that spatial variation in the energy in OPV active layers causes a decrease in the open-circuit voltage. We also show that structural disorder causes the greatest detriment to device performance for feature sizes between 2 and 10 nm. Since this is on the same length scale as the fullerene crystallites in experimental devices, it suggests both that controlling structural disorder is critical to the performance of OPV devices and that the effects of structural disorder should be included in future drift-diffusion modeling studies of organic solar cells.

  19. Structure and genome organization of AFV2, a novel archaeal lipothrixvirus with unusual terminal and core structures

    DEFF Research Database (Denmark)

    Häring, Monika; Vestergaard, Gisle Alberg; Brügger, Kim;

    2005-01-01

    A novel filamentous virus, AFV2, from the hyperthermophilic archaeal genus Acidianus shows structural similarity to lipothrixviruses but differs from them in its unusual terminal and core structures. The double-stranded DNA genome contains 31,787 bp and carries eight open reading frames homologous...

  20. Mineralization of organic matter in gray forest soil and typical chernozem with degraded structure due to physical impacts

    Science.gov (United States)

    Semenov, V. M.; Zhuravlev, N. S.; Tulina, A. S.

    2015-10-01

    The dynamics of the organic matter mineralization in the gray forest soil and typical chernozem with structure disturbed by physical impacts (grinding and extraction of water-soluble substances) were studied in two long-term experiments at the constant temperature and moisture. The grinding of soil to particles of organic matter, along with a short-term increase in the C-CO2 production. The dispersion of the soils with water and leaching of water-soluble organic matter resulted in the significant decrease of the content of potentially mineralizable organic matter in the soils. The physical disturbance caused changes in the ratio of easily mineralizable ( k 1 > 0.1, day-1) and difficultly mineralizable (0.01 > k 3 > 0.001, day-1) fractions in the active pool of soil organic matter. The results of the studies show that the destruction of the structural-aggregate status is one of the reasons for the active soil organic matter depletion and, as a consequence, for the degradation of the properties inherent to the undisturbed soils.

  1. Consistent responses of the microbial community structure to organic farming along the middle and lower reaches of the Yangtze River

    Science.gov (United States)

    Wang, Wenhui; Wang, Hui; Feng, Youzhi; Wang, Lei; Xiao, Xingji; Xi, Yunguan; Luo, Xue; Sun, Ruibo; Ye, Xianfeng; Huang, Yan; Zhang, Zhengguang; Cui, Zhongli

    2016-01-01

    Soil microorganisms play a crucial role in the biogeochemical cycling of nutrient elements and maintaining soil health. We aimed to investigate the response of bacteria communities to organic farming over different crops (rice, tea and vegetable) along the middle and lower reaches of the Yangtze River of China. Compared with conventional farming, organic farming significantly increased soil nutrients, soil enzyme activities, and bacterial richness and diversity. A Venn diagram and principal component analysis revealed that the soils with 3 different crops under organic farming have more number and percent of shared OTUs (operational taxonomic units), and shared a highly similar microbial community structure. Under organic farming, several predominant guilds and major bacterial lineages (Rhizobiales, Thiotrichaceae, Micromonosporaceae, Desulfurellaceae and Myxococcales) contributing to nutrient (C, N, S and P) cycling were enriched, whereas the relative abundances of acid and alkali resistant microorganisms (Acidobacteriaceae and Sporolactobacillaceae) were increased under conventional farming practices. Our results indicated that, for all three crops, organic farming have a more stable microflora and the uniformity of the bacterial community structure. Organic agriculture significantly increased the abundance of some nutrition-related bacteria, while reducing some of the abundance of acid and alkali resistant bacteria. PMID:27725750

  2. Introducing Bond-Line Organic Structures in High School Biology: An Activity that Incorporates Pleasant-Smelling Molecules

    Science.gov (United States)

    Rios, Andro C.; French, Gerald

    2011-01-01

    Chemical education occurs in settings other than just the chemistry classroom. High school biology courses are frequently where students are introduced to organic molecules and their importance to cellular chemistry. However, structural representations are often intimidating because students have not been introduced to the language. As part of a…

  3. Organizational Structure, Authority and Protest: The Case of Union Organizing in the United States, 1990-2001

    Science.gov (United States)

    Martin, Andrew W.

    2007-01-01

    Robert Michels' famous "iron law of oligarchy" has come under criticism from scholars that question assumptions regarding the concentration of power within social movement organizations (SMOs). Despite such concerns, Michels' broader interests in organizational structure and power continue to be relevant for analyzing the goals and strategies of…

  4. Structure and organization of Marchantia polymorpha chloroplast genome. I. Cloning and gene identification.

    Science.gov (United States)

    Ohyama, K; Fukuzawa, H; Kohchi, T; Sano, T; Sano, S; Shirai, H; Umesono, K; Shiki, Y; Takeuchi, M; Chang, Z

    1988-09-20

    We have determined the complete nucleotide sequence of chloroplast DNA from a liverwort, Marchantia polymorpha, using a clone bank of chloroplast DNA fragments. The circular genome consists of 121,024 base-pairs and includes two large inverted repeats (IRA and IRB, each 10,058 base-pairs), a large single-copy region (LSC, 81,095 base-pairs), and a small single-copy region (SSC, 19,813 base-pairs). The nucleotide sequence was analysed with a computer to deduce the entire gene organization, assuming the universal genetic code and the presence of introns in the coding sequences. We detected 136 possible genes. 103 gene products of which are related to known stable RNA or protein molecules. Stable RNA genes for four species of ribosomal RNA and 32 species of tRNA were located, although one of the tRNA genes may be defective. Twenty genes encoding polypeptides involved in photosynthesis and electron transport were identified by comparison with known chloroplast genes. Twenty-five open reading frames (ORFs) show structural similarities to Escherichia coli RNA polymerase subunits, 19 ribosomal proteins and two related proteins. Seven ORFs are comparable with human mitochondrial NADH dehydrogenase genes. A computer-aided homology search predicted possible chloroplast homologues of bacterial proteins; two ORFs for bacterial 4Fe-4S-type ferredoxin, two for distinct subunits of a protein-dependent transport system, one ORF for a component of nitrogenase, and one for an antenna protein of a light-harvesting complex. The other 33 ORFs, consisting of 29 to 2136 codons, remain to be identified, but some of them seem to be conserved in evolution. Detailed information on gene identification is presented in the accompanying papers. We postulated that there were 22 introns in 20 genes (8 tRNA genes and 12 ORFs), which may be classified into the groups I and II found in fungal mitochondrial genes. The structural gene for ribosomal protein S12 is trans-split on the opposite DNA strand

  5. The influence of fibrous elastomer structure and porosity on matrix organization.

    Directory of Open Access Journals (Sweden)

    Jamie L Ifkovits

    Full Text Available Fibrous scaffolds are finding wide use in the field of tissue engineering, as they can be designed to mimic many native tissue properties and structures (e.g., cardiac tissue, meniscus. The influence of fiber alignment and scaffold architecture on cellular interactions and matrix organization was the focus of this study. Three scaffolds were fabricated from the photocrosslinkable elastomer poly(glycerol sebacate (PGS, with changes in fiber alignment (non-aligned (NA versus aligned (AL and the introduction of a PEO sacrificial polymer population to the AL scaffold (composite (CO. PEO removal led to an increase in scaffold porosity and maintenance of scaffold anisotropy, as evident through visualization, mechanical testing, and mass loss studies. Hydrated scaffolds possessed moduli that ranged between ∼3-240 kPa, failing within the range of properties (<300 kPa appropriate for soft tissue engineering. CO scaffolds were completely degraded as early as 16 days, whereas NA and AL scaffolds had ∼90% mass loss after 21 days when monitored in vitro. Neonatal cardiomyocytes, used as a representative cell type, that were seeded onto the scaffolds maintained their viability and aligned along the surface of the AL and CO fibers. When implanted subcutaneously in rats, a model that is commonly used to investigate in vivo tissue responses to biomaterials, CO scaffolds were completely integrated at 2 weeks, whereas ∼13% and ∼16% of the NA and AL scaffolds, respectively remained acellular. However, all scaffolds were completely populated with cells at 4 weeks post-implantation. Polarized light microscopy was used to evaluate the collagen elaboration and orientation within the scaffold. An increase in the amount of collagen was observed for CO scaffolds and enhanced alignment of the nascent collagen was observed for AL and CO scaffolds compared to NA scaffolds. Thus, these results indicate that the scaffold architecture and porosity are important

  6. Organization and Finance of China's Health Sector: Historical Antecedents for Macroeconomic Structural Adjustment.

    Science.gov (United States)

    Li, Hui; Hilsenrath, Peter

    2016-01-01

    China has exploded onto the world economy over the past few decades and is undergoing rapid transformation toward relatively more services. The health sector is an important part of this transition. This article provides a historical account of the development of health care in China since 1949. It also focuses on health insurance and macroeconomic structural adjustment to less saving and more consumption. In particular, the question of how health insurance impacts precautionary savings is considered. Multivariate analysis using data from 1990 to 2012 is employed. The household savings rate is the dependent variable in 3 models segmented for rural and urban populations. Independent variables include out-of-pocket health expenditures, health insurance payouts, housing expenditure, education expenditure, and consumption as a share of gross domestic product (GDP). Out-of-pocket health expenditures were positively correlated with household savings rates. But health insurance remains weak, and increased payouts by health insurers have not been associated with lower levels of household savings so far. Housing was positively correlated, whereas education had a negative association with savings rates. This latter finding was unexpected. Perhaps education is perceived as investment and a substitute for savings. China's shift toward a more service-oriented economy includes growing dependence on the health sector. Better health insurance is an important part of this evolution. The organization and finance of health care is integrally linked with macroeconomic policy in an environment constrained by prevailing institutional convention. Problems of agency relationships, professional hegemony, and special interest politics feature prominently, as they do elsewhere. China also has a dual approach to medicine relying heavily on providers of traditional Chinese medicine. Both of these segments will take part in China's evolution, adding another layer of complexity to policy. PMID

  7. Distribution and structure of internal secretory reservoirs on the vegetative organs of Inula helenium L. (Asteraceae

    Directory of Open Access Journals (Sweden)

    Aneta Sulborska

    2012-12-01

    Full Text Available The aim of the study was to investigate the structure and topography of endogenous secretory tissues of Inula helenium L. By using light and electron microscopy, morphological and anatomical observations of stems, leaves and rhizomes were made. It was shown that in the stems secretory cavities were situated in the vicinity of phloem and xylem bundles. The number of the reservoirs reached its maximum value (34 at shoot flowerig termination, whereas the cavities with the largest diameter were observed at full flowering stage (44.6 µm. In the leaf petioles and midribs, the reservoirs also accompanied the vascular bundles, and their number and size increased along with the growth of the assimilation organs. Observations of the cross sections of the rhizomes revealed the presence of several rings of secretory reservoirs. The measurements of the cavities showed that as a rule the reservoirs with a larger dimension were located in the phelloderm, whereas the smallest ones in the xylem area. The secretory cavities located in the stems and leaves developed by schizogenesis, whereas the rhizome reservoirs were probably formed schizolisygenously. The cells lining the reservoirs formed a one - four-layered epithelium. Observed in TEM, the secretory cells of the mature cavities located in the rhizomes were characterised by the presence of a large central vacuole, whereas the protoplast was largely degraded. Fibrous elements of osmophilic secretion and numerous different coloured vesicles could be distinguished in it. The cell walls formed, from the side of the reservoir lumen, ingrowths into the interior of the epithelial cells. Between the cell wall and the plasmalemma of the glandular cells, a brighter periplasmatic zone with secretory vesicles was observed.

  8. Effects of aneuploidy on genome structure, expression, and interphase organization in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Bruno Huettel

    2008-10-01

    Full Text Available Aneuploidy refers to losses and/or gains of individual chromosomes from the normal chromosome set. The resulting gene dosage imbalance has a noticeable affect on the phenotype, as illustrated by aneuploid syndromes, including Down syndrome in humans, and by human solid tumor cells, which are highly aneuploid. Although the phenotypic manifestations of aneuploidy are usually apparent, information about the underlying alterations in structure, expression, and interphase organization of unbalanced chromosome sets is still sparse. Plants generally tolerate aneuploidy better than animals, and, through colchicine treatment and breeding strategies, it is possible to obtain inbred sibling plants with different numbers of chromosomes. This possibility, combined with the genetic and genomics tools available for Arabidopsis thaliana, provides a powerful means to assess systematically the molecular and cytological consequences of aberrant numbers of specific chromosomes. Here, we report on the generation of Arabidopsis plants in which chromosome 5 is present in triplicate. We compare the global transcript profiles of normal diploids and chromosome 5 trisomics, and assess genome integrity using array comparative genome hybridization. We use live cell imaging to determine the interphase 3D arrangement of transgene-encoded fluorescent tags on chromosome 5 in trisomic and triploid plants. The results indicate that trisomy 5 disrupts gene expression throughout the genome and supports the production and/or retention of truncated copies of chromosome 5. Although trisomy 5 does not grossly distort the interphase arrangement of fluorescent-tagged sites on chromosome 5, it may somewhat enhance associations between transgene alleles. Our analysis reveals the complex genomic changes that can occur in aneuploids and underscores the importance of using multiple experimental approaches to investigate how chromosome numerical changes condition abnormal phenotypes and

  9. Organization and Finance of China's Health Sector: Historical Antecedents for Macroeconomic Structural Adjustment.

    Science.gov (United States)

    Li, Hui; Hilsenrath, Peter

    2016-01-01

    China has exploded onto the world economy over the past few decades and is undergoing rapid transformation toward relatively more services. The health sector is an important part of this transition. This article provides a historical account of the development of health care in China since 1949. It also focuses on health insurance and macroeconomic structural adjustment to less saving and more consumption. In particular, the question of how health insurance impacts precautionary savings is considered. Multivariate analysis using data from 1990 to 2012 is employed. The household savings rate is the dependent variable in 3 models segmented for rural and urban populations. Independent variables include out-of-pocket health expenditures, health insurance payouts, housing expenditure, education expenditure, and consumption as a share of gross domestic product (GDP). Out-of-pocket health expenditures were positively correlated with household savings rates. But health insurance remains weak, and increased payouts by health insurers have not been associated with lower levels of household savings so far. Housing was positively correlated, whereas education had a negative association with savings rates. This latter finding was unexpected. Perhaps education is perceived as investment and a substitute for savings. China's shift toward a more service-oriented economy includes growing dependence on the health sector. Better health insurance is an important part of this evolution. The organization and finance of health care is integrally linked with macroeconomic policy in an environment constrained by prevailing institutional convention. Problems of agency relationships, professional hegemony, and special interest politics feature prominently, as they do elsewhere. China also has a dual approach to medicine relying heavily on providers of traditional Chinese medicine. Both of these segments will take part in China's evolution, adding another layer of complexity to policy.

  10. Synthesis, crystal structure and properties of inorganic-organic hybrid polymers based on 8-hydroxylquinoline-5-sulfonic acid

    Institute of Scientific and Technical Information of China (English)

    WANG Ying; XUE Ming; XU JiaNing; ZHU GuangShan; QIU ShiLun

    2009-01-01

    Two new inorganic-organic hybrid polymers, Mn(QS)(H_2O) (1) and Co(QS)(H_2O)2 (2) (H2QS=8-hydroxylquinoline-5-sulfonic acid), based on 8-hydroxylquinoline-5-sulfonate ligand, have been synthesized under solvothermal conditions and their structures were solved by single-crystal X-ray diffraction analysis. Compound 1 is a three-dimensional open framework with rutile topology structure, and compound 2 is a three-dimensional supramolecular structure. These compounds were characterized by powder XRD, infrared spectroscopy, thermogravimetric analysis, fluorescence properties and magnetism properties.

  11. Synthesis,crystal structure and properties of inorganic-organic hybrid polymers based on 8-hydroxylquinoline-5-sulfonic acid

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Two new inorganic-organic hybrid polymers, Mn(QS)(H2O) (1) and Co(QS)(H2O)2 (2) (H2QS=8-hydroxyl-quinoline-5-sulfonic acid), based on 8-hydroxylquinoline-5-sulfonate ligand, have been synthesized under solvothermal conditions and their structures were solved by single-crystal X-ray diffraction analysis. Compound 1 is a three-dimensional open framework with rutile topology structure, and compound 2 is a three-dimensional supramolecular structure. These compounds were characterized by powder XRD, infrared spectroscopy, thermogravimetric analysis, fluorescence properties and magnetism properties.

  12. Structure-activity relationships to estimate the effective Henry's law coefficients of organics of atmospheric interest

    OpenAIRE

    Raventos-Duran, T.; M. Camredon; R. Valorso; B. Aumont

    2010-01-01

    The Henry's law coefficient is a key property needed to address the multiphase behaviour of organics in the atmosphere. Methods that can reliably predict the values for the vast number of organic compounds of atmospheric interest are therefore required. The effective Henry's law coefficient H* in air-water systems at 298 K was compiled from literature for 488 organic compounds bearing functional groups of atmospheric relevance. This data set was used to assess the reliabili...

  13. Structure-activity relationships to estimate the effective Henry's law constants of organics of atmospheric interest

    OpenAIRE

    Raventos-Duran, T.; M. Camredon; R. Valorso; C. Mouchel-Vallon; Aumont, B.

    2010-01-01

    The Henry's law constant is a key property needed to address the multiphase behaviour of organics in the atmosphere. Methods that can reliably predict the values for the vast number of organic compounds of atmospheric interest are therefore required. The effective Henry's law constant H* in air-water systems at 298 K was compiled from literature for 488 organic compounds bearing functional groups of atmospheric relevance. This data set was used to ass...

  14. Efficiency enhancement due to self-organization of nano-structures in Cd(S, Te) solar cell material

    Science.gov (United States)

    Sato, Kazunori; Katayama-Yoshida, Hiroshi

    2014-03-01

    CdTe is one of the most important solar cell materials. Its energy gap is 1.44 eV, which is ideal for solar cell application. So far, conversion efficiency of 18.3 percent has been realized, but it is lower than the Shockley-Queisser limit. In this paper, we propose computational materials design for enhancing conversion efficiency by using self-organization in Cd(Te, S) alloy semiconductor. Firstly, we performed cluster expansion of total energy of the Cd(Te, S) system and simulated self-organization of nano-structures in Cd(Te, S) by using Monte Carlo method. It is found that layered structure becomes stable by applying strain during the crystal growth. The electronic structure of the self-organized layered structure was calculated by using the hybrid method (HSE06) implemented in the VASP code to derive optical absorption coefficient. By using the calculated absorption coefficient the efficiency limit was derived based on the Shockley-Queisser theory. It is shown that the efficiency limit does not change so much due to the nano-structure formation. However, our calculation shows spatial separation between photo-generated electrons and holes. This might enhance the efficiency due to the suppression of recombination.

  15. Photoluminescence polarization anisotropy for studying long-range structural ordering within semiconductor multi-atomic alloys and organic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Prutskij, T.; Percino, J. [Instituto de Ciencias, BUAP, Privada 17 Norte, No 3417, col. San Miguel Huyeotlipan, 72050, Puebla, Pue. (Mexico); Orlova, T. [Department of Chemical and Biochemical Engineering, University of Notre Dame, Notre Dame, IN (United States); Vavilova, L. [Ioffe Physical-Technical Institute, 26 Polytekhnicheskaya, St Petersburg 194021, Russian Federation (Russian Federation)

    2013-12-04

    Long-range structural ordering within multi-component semiconductor alloys and organic crystals leads to significant optical anisotropy and, in particular, to anisotropy of the photoluminescence (PL) emission. The PL emission of ternary and quaternary semiconductor alloys is polarized if there is some amount of the atomic ordering within the crystal structure. We analyze the polarization of the PL emission from the quaternary GaInAsP semiconductor alloy grown by Liquid Phase Epitaxy (LPE) and conclude that it could be caused by low degree atomic ordering within the crystal structure together with the thermal biaxial strain due to difference between the thermal expansion coefficients of the layer and the substrate. We also study the state of polarization of the PL from organic crystals in order to identify different features of the crystal PL spectrum.

  16. Highly Efficient Nondoped Organic Light Emitting Diodes Based on Thermally Activated Delayed Fluorescence Emitter with Quantum-Well Structure.

    Science.gov (United States)

    Meng, Lingqiang; Wang, Hui; Wei, Xiaofang; Liu, Jianjun; Chen, Yongzhen; Kong, Xiangbin; Lv, Xiaopeng; Wang, Pengfei; Wang, Ying

    2016-08-17

    Highly efficiency nondoped thermally activated delayed fluorescence (TADF) organic light emitting diodes (OLEDs) with multiquantum wells structure were demonstrated. By using an emitting layer with seven quantum wells, the nondoped TADF OLEDs exhibit high efficiency with EQE of 22.6%, a current efficiency of 69 cd/A, and a power efficiency of 50 lm/W, which are higher than those of the conventional doped OLED and among the best of the TADF OLEDs. The high performance of the devices can be ascribed to effective confinement of the charges and excitons in the emission layer by the quantum well structure. The emission layer with multiquantum well structure is demonstrated to be cost effective for highly efficient nondoped TADF OLEDs and holds great potential for organic electronics.

  17. The structure of the nasal chemosensory system in squamate reptiles. 2. Lubricatory capacity of the vomeronasal organ

    Indian Academy of Sciences (India)

    Susan J Rehorek; Bruce T Firth; Mark N Hutchinson

    2000-06-01

    The vomeronasal organ is a poorly understood accessory olfactory organ, present in many tetrapods. In mammals, amphibians and lepidosaurian reptiles, it is an encapsulated structure with a central, fluid-filled lumen. The morphology of the lubricatory system of the vomeronasal organ (the source of this fluid) varies among classes, being either intrinsic (mammalian and caecilian amphibian vomeronasal glands) or extrinsic (anuran and urodele nasal glands). In the few squamate reptiles thus far examined, there are no submucosal vomeronasal glands. In this study, we examined the vomeronasal organs of several species of Australian squamates using histological, histochemical and ultrastructural techniques, with the goal of determining the morphology of the lubricatory system in the vomeronasal organ. Histochemically, the fluid within the vomeronasal organ of all squamates is mucoserous, though it is uncertain whether mucous and serous constituents constitute separate components. The vomeronasal organ produces few secretory granules intrinsically, implying an extrinsic source for the luminal fluid. Of three possible candidates, the Harderian gland is the most likely extrinsic source of this secretion.

  18. Self-Organization of Temporal Structures — A Possible Solution for the Intervention Problem

    Science.gov (United States)

    von Lucadou, Walter

    2006-10-01

    -local correlations. The structure of the data, however, allows the conclusion, that all observed correlations can be considered as entanglement-correlations. The number of entanglement-correlations was significantly higher for the highly motivated group (data set 2) than for the unselected group of the exhibition participants (data set 3). The latter, however, where not completely unsuccessful: A subgroup who showed "innovative" behavior also showed significant entanglement-correlations. It could further be shown, that the structure of the matrix of entanglement-correlations is not stable in time and changes if the experiment is repeated. In comparison with previous correlation-experiments, no decline of the effect size was observed. These results are in agreement with the predictions of the "Weak Quantum Theory (WQT)" and the "Model of Pragmatic Information (MPI)". These models interpret the measured correlations as entanglement-correlations within a self-organizing, organizationally closed, psycho-physical system that exist during a certain time-interval (as long as the system is active). The entanglement-correlations cannot be considered as a causal influence (in the sense of a PK-Influence) and thus are called "micro-synchronicity". After a short introduction (1.), the question is discussed how non-local correlations can be created in psycho-physical systems (2.). In chapter (3.) the description of the experimental setting is given and the apparatus (4.) and randomness test of the random event generator (5.) are described. Additionally, an overview of the structure of the data is given (6.) and the analysis methods are described (7.). In chapter (8.) the experimental hypotheses are formulated and the results are reported (9.). After the discussion of the results (10.) the conclusions (11).) of the study are presented.

  19. Study on organization transform of public organizations based on organization structure%基于组织结构的公共部门组织变革研究

    Institute of Scientific and Technical Information of China (English)

    汪朗峰; 伏玉林

    2013-01-01

    通过组织变革来提高组织收益是公共部门机构改革的重要课题.已有文献表明,因为无法描述组织的结构特征和公共事务的差异性,组织变革的研究正面临瓶颈.本文根据公共事务发生地区性和职能性特征,构建了描述公共事务多重多任务特征的概率模型,用于分析公共部门的组织结构特征,并从组织收益提高视角研究了组织变革.研究结果表明,基于公共部门组织结构进行的组织变革可以明显提高组织收益.相关结果可以为公共部门的机构改革提供组织变革方面的参考.%It' s an important subject for bureaucracy reform of public sectors to improve the organization' s gain through organizational structure change. Previous studies cannot give efficient methods for organization structure change because they cannot describe the organizational structure features and differences of public affairs. This paper described multiple & the multi-task features of public affairs, presented organizational structures of the public sector based on the probabilistic model, and optimized organizational structures by organizational gains. Mathematical analysis result shows that the organizations gains can be improved significantly based on the organizational structure change in the public sector. Results can be provided for reference to the organizational structure change for bureaucracy reform of public sector.

  20. Amorphous oxide alloys as interfacial layers with broadly tunable electronic structures for organic photovoltaic cells.

    Science.gov (United States)

    Zhou, Nanjia; Kim, Myung-Gil; Loser, Stephen; Smith, Jeremy; Yoshida, Hiroyuki; Guo, Xugang; Song, Charles; Jin, Hosub; Chen, Zhihua; Yoon, Seok Min; Freeman, Arthur J; Chang, Robert P H; Facchetti, Antonio; Marks, Tobin J

    2015-06-30

    In diverse classes of organic optoelectronic devices, controlling charge injection, extraction, and blocking across organic semiconductor-inorganic electrode interfaces is crucial for enhancing quantum efficiency and output voltage. To this end, the strategy of inserting engineered interfacial layers (IFLs) between electrical contacts and organic semiconductors has significantly advanced organic light-emitting diode and organic thin film transistor performance. For organic photovoltaic (OPV) devices, an electronically flexible IFL design strategy to incrementally tune energy level matching between the inorganic electrode system and the organic photoactive components without varying the surface chemistry would permit OPV cells to adapt to ever-changing generations of photoactive materials. Here we report the implementation of chemically/environmentally robust, low-temperature solution-processed amorphous transparent semiconducting oxide alloys, In-Ga-O and Ga-Zn-Sn-O, as IFLs for inverted OPVs. Continuous variation of the IFL compositions tunes the conduction band minima over a broad range, affording optimized OPV power conversion efficiencies for multiple classes of organic active layer materials and establishing clear correlations between IFL/photoactive layer energetics and device performance.

  1. Capturing neon - the first experimental structure of neon trapped within a metal-organic environment.

    Science.gov (United States)

    Wood, Peter A; Sarjeant, Amy A; Yakovenko, Andrey A; Ward, Suzanna C; Groom, Colin R

    2016-08-21

    Despite being the fifth most abundant element in the atmosphere, neon has never been observed in an organic or metal-organic environment. This study shows the adsorption of this highly unreactive element within such an environment and reveals the first crystallographic observation of an interaction between neon and a transition metal.

  2. Capturing neon - the first experimental structure of neon trapped within a metal-organic environment.

    Science.gov (United States)

    Wood, Peter A; Sarjeant, Amy A; Yakovenko, Andrey A; Ward, Suzanna C; Groom, Colin R

    2016-08-21

    Despite being the fifth most abundant element in the atmosphere, neon has never been observed in an organic or metal-organic environment. This study shows the adsorption of this highly unreactive element within such an environment and reveals the first crystallographic observation of an interaction between neon and a transition metal. PMID:27452474

  3. Soil microbial community structure and target organisms under different fumigation treatments

    Science.gov (United States)

    Several high-value crop producers in California rely heavily on soil fumigants to control key diseases, nematodes, weeds and volunteer crops. Fumigants with broad biocidal activity can affect both target and non-target soil organisms. The ability of non-target soil organisms to recover after fumigat...

  4. Influence of molecular structure on the laser-induced plasma emission of the explosive RDX and organic polymers.

    Science.gov (United States)

    De Lucia, Frank C; Gottfried, Jennifer L

    2013-10-01

    A series of organic polymers and the military explosive cyclotrimethylenetrinitramine (RDX) were studied using the light emission from a femtosecond laser-induced plasma under an argon atmosphere. The relationship between the molecular structure and plasma emission was established by using the percentages of the atomic species (C, H, N, O) and bond types (C-C, C═C, C-N, and C≡N) in combination with the atomic/molecular emission intensities and decay rates. In contrast to previous studies of organic explosives in which C2 was primarily formed by recombination, for the organic materials in this study the percentage of C-C (and C═C) bonds was strongly correlated to the molecular C2 emission. Time-resolved emission spectra were collected to determine the lifetimes of the atomic and molecular species in the plasma. Observed differences in decay rates were attributed to the differences in both the molecular structure of the organic polymers or RDX and the chemical reactions that occur within the plasma. These differences could potentially be exploited to improve the discrimination of explosive residues on organic substrates with laser-induced breakdown spectroscopy.

  5. The impact of drying on structure of sedimentary organic matter in wetlands: Probing with native and amended polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Wang, Zucheng; Liu, Zhanfei; Liu, Min; Xu, Kehui; Mayer, Lawrence M

    2016-10-15

    Wetland sediments undergo dry-wet cycles that may change their structural properties and affect geochemical behavior of associated organic compounds. In this study, we examined the effect of drying on particle size distributions and the rapid (24h) sorption reactions of polycyclic aromatic hydrocarbons (PAHs) with salt marsh sediments in Nueces Delta, South Texas. Drying reduced the fraction of fine particles in organically richer sediments, indicating structural rearrangement of organic matter and mineral aggregates. Among the 16 EPA priority PAHs examined, dried sediment preferentially released 1.0-7.5% of phenanthrene, fluoranthene and pyrene to added seawater (solid: water mass ratio of 1/100) - significantly greater than release from sediments maintained in the wet state. On the other hand, drying also increased the affinity of sedimentary organic matter (SOM) for experimentally amended (deuterated) phenanthrene relative to continually wet sediments. Further, deuterated phenanthrene was even more effectively retained when it was added to wet sediment that was subsequently dried and rewetted. These apparently contradictory results can be reconciled and explained by SOM having a heterogeneous distribution of hydrophobic and hydrophilic zones - e.g., a zonal model. We propose that drying changed the orientation of amphiphilic SOM, exposing hydrophobic zones and promoting the release of some of their native PAHs to water. Freshly amended PAHs were only able to penetrate into the surface hydrophobic zone and/or deeper but rapidly accessible ("kinetic") zone in wet sediments due to the brief adsorption contact time. Subsequent drying presumably then induced structural changes in SOM that isolated these amended PAHs in sites inaccessible to water exchange in the next rewetting. These results provide insights into structural changes of SOM upon drying, and help predict the fate of compounds such as organic contaminants during drought/flood oscillations.

  6. Megacomplex organization of the oxidative phosphorylation system by structural analysis of respiratory supercomplexes from potato

    NARCIS (Netherlands)

    Bultema, Jelle B.; Braun, Hans-Peter; Boekema, Egbert J.; Kouril, Roman; Kouřil, Roman

    2009-01-01

    The individual protein complexes of the oxidative phosphorylation system (OXPHOS complexes 1 to V) specifically interact and form defined supramolecular structures, the so-called "respiratory supercomplexes". Some supercomplexes appear to associate into larger structures, or megacomplexes, such as a

  7. Electronic structure of self-organized InAs/GaAs quantum dots bounded by {136} facets

    International Nuclear Information System (INIS)

    Recent experiments indicate that the shape of self-organized InAs quantum dots grown on GaAs [001] is an elongated pyramid with bounding facets corresponding to a family of four {136} planes. This structure, which possesses C2v symmetry, is quite different from square-base pyramidal or lens geometries, which have been assumed in previous electronic structure calculations for this system. In this paper, we consider theoretically the influence of the {136} shape on the electronic structure and optical properties of the quantum dots. We present a valence force-field calculation of the inhomogeneous strain and incorporate the results into an eight band k(vector sign)·p(vector sign) electronic structure calculation. The size dependence of the electronic structure is calculated and compared to experimental photoluminescence spectra. The effects of perturbations on the {136} shape are also considered. Calculations based on the {136} shape give good agreement with the observed level structure and optical polarization properties of self-organized InAs/GaAs quantum dots. (c) 2000 The American Physical Society

  8. The Impact of Structural Empowerment on Organizational Citizenship Behavior-Organization and Job Performance: A Mediating Role of Burnout

    Directory of Open Access Journals (Sweden)

    Hina Jaffery

    2015-10-01

    Full Text Available The banking sector employees are usually exposed to potential job burnout which impacts their employee performance. This study examined the impact of structural empowerment on organizational citizenship behavior-organization (henceforth, OCBO and job performance and further examined the mediating effect of job burnout in the relationships of structural empowerment, OCBO and job performance. In this study, data from 282 employees was taken from four banks: both public and private sectors. Two stage sampling technique was carried out to collect data. In the first stage probability cluster sampling and in the second stage convenience sampling was used. Different data analysis techniques like correlation, regression analysis, were used to test the four hypotheses of the study. Findings show that there are strong positive relationships of structural empowerment with OCBO and job performance. It has also proved that job burnout strongly mediates the relationship of structural empowerment and organizational citizenship-behavior (OCBO and weakly mediates the relationship between structural empowerment and job performance. The findings would help the HR executives of the organizations to formulate future development to combat the burnout and ensure effective overall performance of employees through structurally empowering them.

  9. Management-induced Soil Structure Degradation: Organic Matter Depletion and Tillage

    OpenAIRE

    Kay, B.D.; Munkholm, L.J.

    2004-01-01

    Soil structure is an important element of soil quality since changes in structural characteristics can cause changes in the ability of soil to fulfil different functions and services. Emphasis in this chapter is placed on the role of soil structure in biological productivity of agroecosystems. Combinations of management practices in which the extent of the degradation of soil structure caused by one practice is balanced or exceeded by the extent of regeneration by other practices will help su...

  10. Optical nonlinearity and structural phase-transition observation of organic dye-doped polymer silica hybrid material.

    Science.gov (United States)

    Xu, L; Hou, Z; Liu, L; Xu, Z; Wang, W; Li, F; Ye, M

    1999-10-01

    The optical nonlinearity of organic dye-doped poly(methyl methacrylate) (PMMA)-silica-gel hybrid material was investigated by second-harmonic-generation measurement. We found that incorporation of in situ polymerized solgel precursors into the organic dye-doped PMMA significantly improved the nonlinear optical stability of the system. However, improvement of thermal stability occurred only when a sufficient amount of silica gel was incorporated. A structural phase transition from pure polymer to a hybrid system was found near a 10-mol.% silica-gel concentration. The optimum polymer/tetraethoxysilane molar ratio is 2:1 to 1:1. PMID:18079805

  11. Comparison of Structural and Electrochemical Properties of V2O5 Thin Films Prepared by Organic/Inorganic Precursors

    International Nuclear Information System (INIS)

    Vanadium pentoxide thin films were produced from organic and inorganic precursors by sol gel dip-coating method. Fourier transform infrared spectroscopy and UV Vis spectroscopy were made to figure out structural properties of the films. Electrochemical properties were investigated by cyclic voltammetry. The shape of the curves was in agreement with a typical diffusion controlled cyclic voltammograms of amorphous V2O5 films for a reversible lithium ion intercalation/deintercalation process showing yellow–green–blue multi-electrochromism. V2O5 films, synthesized from organic precursor, indicated lower band gap energy, higher charge capacity as well as homogeneous and low granule size compared to inorganic route

  12. THE STORY OF STRUCTURAL ADJUSTMENT PROGRAMME IN NIGERIA FROM THE PERSPECTIVE OF THE ORGANIZED LABOUR

    Directory of Open Access Journals (Sweden)

    NWAGBARA, EUCHARIA NWABUGO

    2011-10-01

    Full Text Available The process of achieving the set objectives of structural adjustment programme (SAP produced adverse social effects that put to question the sincerity of purpose of the SAP policy designers and implementers. To be able to generate conclusions concerning how the politics of enhancing the “well-being” of the people via SAP played out in the Nigerian society, in terms of how well the programme served the intended purpose, questions have to be asked, and responses elicited. Earlier attempts at appraising the SAP were geared toward examining the successes or failures of the adjusting countries in implementing the policies. Such appraisal gave rise to concern on the issue of good governance as a necessary and inevitable prerequisite of effective economic reform. At the same time, not much effort was made at ascertaining the social fallouts of the entire reform process. Even when the outburst of public outcry within the adjusting countries necessitated the recognition of the importance of the social dimension of SAP, little effort was made at understanding the problem from the perspective of the aggrieved populace. What we see is a proliferation of World Bank sponsored studies on the issue that hardly take cognizance of the people‟s feelings. Thus the findings of such studies cannot be said to be representative of the views of all the stakeholders. This paper attempts to fill this gap by examining organized labour‟s/interest groups‟ response to SAP from the lens of the public sector workers and why they reacted the way they did toward the entire process. A sample of 357 respondents was randomly selected from university teachers, students and other public servants within Calabar metropolis. The findings, which were described in simple percentages, show significant relationship between economic hardship, repressive attitude of government, political uncertainty and interest groups‟ protests against SAP. The author recommends the provision of

  13. Aberrant Global and Regional Topological Organization of the Fractional Anisotropy-weighted Brain Structural Networks in Major Depressive Disorder

    Institute of Scientific and Technical Information of China (English)

    Jian-Huai Chen; Zhi-Jian Yao; Jiao-Long Qin; Rui Yan; Ling-Ling Hua; Qing Lu

    2016-01-01

    Background:Most previous neuroimaging studies have focused on the structural and functional abnormalities of local brain regions in major depressive disorder (MDD).Moreover,the exactly topological organization of networks underlying MDD remains unclear.This study examined the aberrant global and regional topological patterns of the brain white matter networks in MDD patients.Methods:The diffusion tensor imaging data were obtained from 27 patients with MDD and 40 healthy controls.The brain fractional anisotropy-weighted structural networks were constructed,and the global network and regional nodal metrics of the networks were explored by the complex network theory.Results:Compared with the healthy controls,the brain structural network of MDD patients showed an intact small-world topology,but significantly abnormal global network topological organization and regional nodal characteristic of the network in MDD were found.Our findings also indicated that the brain structural networks in MDD patients become a less strongly integrated network with a reduced central role of some key brain regions.Conclusions:All these resulted in a less optimal topological organization of networks underlying MDD patients,including an impaired capability of local information processing,reduced centrality of some brain regions and limited capacity to integrate information across different regions.Thus,these global network and regional node-level aberrations might contribute to understanding the pathogenesis of MDD from the view of the brain network.

  14. The communication of meaning and the structuration of expectations: Giddens' "structuration theory" and Luhmann's "self-organization"

    NARCIS (Netherlands)

    L. Leydesdorff

    2010-01-01

    The communication of meaning as distinct from (Shannon-type) information is central to Luhmann's social systems theory and Giddens' structuration theory of action. These theories share an emphasis on reflexivity, but focus on meaning along a divide between interhuman communication and intentful acti

  15. High Performance Work Systems as an Enabling Structure for Self-organized Learning Processes

    OpenAIRE

    Thomas Wallner; Martin Menrad

    2012-01-01

    High Performance Work Systems (HPWSs) as a new way of organizing work in general and of production work in particular provide an environment, where self-organized learning processes are enabled and fostered. In an extensive research project in 2 major Austrian manufacturing companies we currently investigate the applicability and the effects of HPWS including issues of learning and knowledge management. In this contribution we present the results of the first phase of this project discussing ...

  16. Structure-performance correlations in vapor phase deposited self-assembled nanodielectrics for organic field-effect transistors.

    Science.gov (United States)

    DiBenedetto, Sara A; Frattarelli, David L; Facchetti, Antonio; Ratner, Mark A; Marks, Tobin J

    2009-08-12

    Organic field-effect transistor (OFETs) are fabricated using thin, vapor-deposited films of both the gate dielectric (vapor-deposited self-assembled nanodielectric, v-SAND) and the organic semiconductor. The nanoscopic self-assembled gate dielectrics are structurally organized via molecular precursor hydrogen-bonding interactions, followed by planarization with a vapor-deposited inorganic SiO(x) film. It is shown here that the metal-insulator-semiconductor (MIS) and OFET device electrical properties are sensitive to the v-SAND molecular dipolar orientation. In addition, alternating (organic/inorganic/organic/...) and nonalternating (1 organic layer + 1 inorganic layer) v-SAND microstructural arrangements are investigated, and the microstructures are correlated with MIS and OFET device characteristics. Films with alternating microstructures have larger capacitances than nonalternating films of the same thickness. However, they also have larger leakage currents, associated with the enhanced polarization of well-ordered dipolar films. For pentacene OFETs, the largest mobilities (approximately 3 cm(2)/(V s)) are associated with the high-capacitance nonalternating microstructure, and the lowest mobilities (approximately 0.5 cm(2)/(V s)) are associated with the alternating microstructure. v-SAND gated ambient-stable, n-type organic semiconductors show the opposite trends, where slightly greater OFET performance is observed with the lower-capacitance gate dielectric. For the p-type and one of the n-type v-SAND-based OFETs, the performance (under vacuum and ambient) is comparable to, or surpasses, that of previously reported devices using conventional SiO(2) as the gate dielectric. More importantly, the devices fabricated here operate at far lower voltages. These results indicate that v-SAND dielectrics are promising for future flexible organic electronics requiring low-temperature, solvent-free deposition conditions.

  17. Synthesis, crystal structures and properties of lanthanide-organic frameworks based benzene carboxylates with two/three-dimensional structure

    International Nuclear Information System (INIS)

    A series of lanthanide coordination polymers, {[Dy3(1,3-BDC)4(NO3)(phen)3]·2H2O}n (1), {[Dy2(1,3-BDC)3(H2O)2]·H2O}n (2), {[Ln4(1,3-BDC)6(DMF)(H2O)4]·DMF·2H2O}n (Ln=Tb (3), Ho (4), Er (5), 1,3-H2BDC=1,3-benzenedicarboxylate, phen=1,10-phenanthroline, DMF=N,N-dimethylformamide), have been synthesized and characterized. In coordination polymer 1, each Dy3+ ion is connected to its neighboring Dy3+ ion through bridging carboxyl oxygen atoms of the 1,3-BDC2− ligands to form a new three-dimensional open-framework structure which the Schläfli symbol of {64·82}2{66}. In coordination polymer 2, center metal dysprosium ions are interlaced and connected through bridging carboxyl oxygen atoms to form an infinite helix chain. Two helix chains are linked through the 1,3-BDC2− ligand to give rise to the two-dimensional layered structure. Coordination polymers 3–5 are isomorphous, which displays a (3,4)-connected net with the point symbol of {42·63·8}{42·6}. The solid-state photoluminescence properties and lifetimes of the Dy (1 and 2) and Tb (3) coordination polymers have been measured at room temperature. Highlights: ► Five lanthanide coordination polymers based on 1,3-H2BDC were obtained. ► The polymers were structurally characterized by single-crystal X-ray diffraction. ► Coordination polymers 1–5 display different topological structures. ► They show characteristic emissions of lanthanide ions in the solid state.

  18. sp(2)-sp(3) diboranes: astounding structural variability and mild sources of nucleophilic boron for organic synthesis.

    Science.gov (United States)

    Dewhurst, Rian D; Neeve, Emily C; Braunschweig, Holger; Marder, Todd B

    2015-06-14

    Despite the widespread use of organoborane reagents in organic synthesis and catalysis, a major challenge still remains: very few boron-centered nucleophiles exist for the direct construction of B-C bonds. Perhaps the most promising emerging solution to this problem is the use of sp(2)-sp(3) diboranes, in which one boron atom of a conventional diborane(4) is quaternised by either a neutral or anionic nucleophile. These compounds, either isolated or generated in situ, serve as relatively mild and convenient sources of the boryl anion [BR2](-) for use in organic synthesis and have already proven their efficacy in metal-free as well as metal-catalysed borylation reactions. This Feature article documents the history of sp(2)-sp(3) diborane synthesis, their properties and surprising structural variability, and their burgeoning utility in organic synthesis.

  19. Comparative SAXS and DSC study on stratum corneum structural organization in an epidermal cell culture model (ROC)

    DEFF Research Database (Denmark)

    Kuntsche, Judith; Herre, Angela; Fahr, Alfred;

    2013-01-01

    barrier similar to that of human stratum corneum is, however, a prerequisite. In this study, the stratum corneum lipid organization in an epidermal cell culture model based on rat epidermal keratinocytes (REK organotypic culture, ROC) was investigated by small-angle X-ray scattering (SAXS) in dependence......Cell cultured skin equivalents present an alternative for dermatological in vitro evaluations of drugs and excipients as they provide the advantage of availability, lower variability and higher assay robustness compared to native skin. For penetration/permeation studies, an adequate stratum corneum...... and SC lipid organization. Cultivation for 21days resulted in further minor changes in the structural organization of ROC SC. The SAXS patterns of ROC SC had overall large similarities with that of human SC and point to the presence of a long periodicity phase with a repeat distance of about 122Å, e...

  20. CONJUNCTIVE STRUCTURES IN THE POSITION OF NEWSPAPER HEADLINES AND THEIR COMMUNICATIVE ORGANIZATION (ON THE BASIS OF ARABIC PRESS

    Directory of Open Access Journals (Sweden)

    Sabinina Elena Aleksandrovna

    2013-02-01

    Full Text Available The language of modern Arabic press is developing extensively, which manifests itself in the special syntactical structure of headlines. The article describes the communicative organization of conjunctive structures in the position of modern Arabic newspaper headlines. The academic novelty of the paper lies in the topic of Arabic newspaper headlines, which hasn’t received adequate scientific attention in native Arab studies yet. Besides, the conjunctive coordinating structures selected for research are analyzed not formally, but in the context of actual division of the sentence. The article considers the structural peculiarities of conjunctive headlines and the functions of word order, coordinating conjunction and punctuation marks in their communicative division. The results of the study show that Arabic conjunctive headlines have a multilevel communicative structure, where word order plays a big role in the formation of communicative organization of such constructions. A special emphasis is placed on the functions of punctuation marks in the delivery of non-verbal context of situation. The study of the examined phenomenon enables not only to clarify the peculiarities of syntactic models of Arabic coordinating headlines, but also makes a weighty contribution to the description of syntax of written texts in modern Arabic.

  1. CONJUNCTIVE STRUCTURES IN THE POSITION OF NEWSPAPER HEADLINES AND THEIR COMMUNICATIVE ORGANIZATION (ON THE BASIS OF ARABIC PRESS

    Directory of Open Access Journals (Sweden)

    Елена Александровна Сабинина

    2013-04-01

    Full Text Available The language of modern Arabic press is developing extensively, which manifests itself in the special syntactical structure of headlines. The article describes the communicative organization of conjunctive structures in the position of modern Arabic newspaper headlines. The academic novelty of the paper lies in the topic of Arabic newspaper headlines, which hasn’t received adequate scientific attention in native Arab studies yet. Besides, the conjunctive coordinating structures selected for research are analyzed not formally, but in the context of actual division of the sentence. The article considers the structural peculiarities of conjunctive headlines and the functions of word order, coordinating conjunction and punctuation marks in their communicative division. The results of the study show that Arabic conjunctive headlines have a multilevel communicative structure, where word order plays a big role in the formation of communicative organization of such constructions. A special emphasis is placed on the functions of punctuation marks in the delivery of non-verbal context of situation. The study of the examined phenomenon enables not only to clarify the peculiarities of syntactic models of Arabic coordinating headlines, but also makes a weighty contribution to the description of syntax of written texts in modern Arabic.DOI: http://dx.doi.org/10.12731/2218-7405-2013-2-31

  2. MOLECULAR DYNAMICS SIMULATION OF SELF-ORGANIZED STRUCTURE IN MICRO-PHASE SEPARATION OF NANO-SCALE FILM

    Institute of Scientific and Technical Information of China (English)

    Dexiang Tang; Wei Ge; Jinghai Li

    2004-01-01

    Self-organization in thin micro-films has shown potential for the production of microelements with specific structures and functions; however, little is known about its mechanism of formation. A 2-D molecular dynamics (MD)simulation on this process is carried out in this paper for films between two parallel walls (substrates) under different initial conditions. The films consist of two immiscible components (A and B). The simulation results in alternative columns perpendicular to the walls, which are rich either in A or in B molecules, respectively, apparently owing to their different interactions with the walls. The characteristic breadths of the columns depend on the distance between the two walls. By providing microscopic details of the self-organization processes and the resulted structures, MD simulation proves itself as a unique way for analyzing the dynamics of thin films.

  3. Control of electrochemical signals from quantum dots conjugated to organic materials by using DNA structure in an analog logic gate.

    Science.gov (United States)

    Chen, Qi; Yoo, Si-Youl; Chung, Yong-Ho; Lee, Ji-Young; Min, Junhong; Choi, Jeong-Woo

    2016-10-01

    Various bio-logic gates have been studied intensively to overcome the rigidity of single-function silicon-based logic devices arising from combinations of various gates. Here, a simple control tool using electrochemical signals from quantum dots (QDs) was constructed using DNA and organic materials for multiple logic functions. The electrochemical redox current generated from QDs was controlled by the DNA structure. DNA structure, in turn, was dependent on the components (organic materials) and the input signal (pH). Independent electrochemical signals from two different logic units containing QDs were merged into a single analog-type logic gate, which was controlled by two inputs. We applied this electrochemical biodevice to a simple logic system and achieved various logic functions from the controlled pH input sets. This could be further improved by choosing QDs, ionic conditions, or DNA sequences. This research provides a feasible method for fabricating an artificial intelligence system. PMID:27116705

  4. Preparation and Annealing-Induced Structural Transition of Self-Organized Nanostripes on the Electropolished Aluminium Surface

    Institute of Scientific and Technical Information of China (English)

    郭柱; 侯士敏; 申自勇; 赵兴钰; 刘惟敏; 薛增泉

    2002-01-01

    Self-organized nanostripe patterns with a wavelength of l00nm and an amplitude of 4 - 5nm were formed Seon the surface of high-purity aluminium by electropolishing. The thermal stability of the nanostripe patterns was investigated experimentally by using a needle-sensor atomic force microscope in an ultra-high vacuum after annealing the sample in a high vacuum. We found that the originally highly ordered nanostripe structures transformed into many domains separated by various boundaries, and different nanostripe patterns formed, the belt-like boundaries especially formed "cross" patterns on the surface. We also found that the vacuum annealing had the tendency to efface the nanostripe structures.

  5. Layered inorganic-organic hybrid with talc-like structure for cation removal at the solid/liquid interface

    Energy Technology Data Exchange (ETDEWEB)

    Badshah, Syed [Institute of Chemistry, University of Campinas, UNICAMP, P.O. Box 6154, 13084-971 Campinas, SP (Brazil); Airoldi, Claudio, E-mail: airoldi@iqm.unicamp.br [Institute of Chemistry, University of Campinas, UNICAMP, P.O. Box 6154, 13084-971 Campinas, SP (Brazil)

    2013-01-20

    Graphical abstract: A lamellar inorganic-organic hybrid with talc-like structure has been synthesized through a single sol-gel step. Highlights: Black-Right-Pointing-Pointer New silylating agent isolated from acrylamide includes basic centers attached to enlarged chain. Black-Right-Pointing-Pointer Lamellar inorganic-organic talc-like structure has been synthesized through a single sol-gel step. Black-Right-Pointing-Pointer High basal distance accommodates the pendant chain in the cavities only in inclined disposition. Black-Right-Pointing-Pointer The pendant chain sorbs spontaneously and favorable cations as demonstrated by thermodynamic data. - Abstract: A new silylating agent N-((3-(3-(trimethoxysilyl)propylthio)propanamido)methyl)acrylamide synthesized from the reaction of N,N-methylenebisacrylamide and 3-mercaptopropyltrimethoxysilane yielded layered inorganic-organic talc-like magnesium phyllosilicate through the sol-gel process. Elemental analysis data based on sulfur demonstrated incorporation of 2.70 mmol g{sup -1} of organic moiety inside the lamellar cavities and the X-ray diffraction patterns confirmed the talc-like structure with a basal distance of 2.11 nm. Infrared spectroscopy, {sup 13}C and {sup 29}Si NMR in the solid state are in agreement with the presence of organic chains covalently bonded to the inorganic lamellar framework, as also supported by the presence of T{sup n} silicon species. Nitrogen, oxygen and sulfur basic centers sorb divalent lead, copper and cobalt cations with maximum capacity of 5.30, 3.82 and 1.60 mmol g{sup -1}. The thermodynamic data for cation/basic center interactions at the solid/liquid interface were determined through calorimetric titration with exothermic enthalpy, negative Gibbs energy and positive entropy, as expected for spontaneous and favorable reaction conditions.

  6. Optimizing The Organic/Inorganic Barrier Structure For Flexible Plastic Substrate Encapsulation

    OpenAIRE

    Yi-Chiuan Lin; Quoc-Khoa Le; Li-Wei Lai; Ren-Mao Liao; Ming-Shin Jeng; Day-Shan Liu

    2012-01-01

    A multilayered barrier structure stacked with organosilicon and silicon oxide (SiOx) films consecutively prepared using plasma-enhanced chemical vapor deposition (PECVD) was developed to encapsulate flexible plastic substrate. The evolution on the residual internal stress, structural quality of the organosilicon/SiOx multilayered structure as well as its adhesion to the substrate were found to correlate closely with the thickness of the inset organosilicon layer. Due to the signif...

  7. Synergetic effect of organic cores and inorganic shells for core/shell structured composite abrasives for chemical mechanical planarization

    International Nuclear Information System (INIS)

    Highlights: • The damage-free polishing mechanism of core/shell composite abrasive was explored. • The organic core is help to decrease surface roughness and mechanical damages. • The inorganic shell is in favor of improving material removal rate. • The enhanced CMP behavior is due to the synergistic effect between core and shell. - Abstract: Core/shell structured organic/inorganic composite microspheres has an important potential application in efficient and damage-free chemical mechanical planarization/polishing (CMP) as a kind of novel abrasive due to its uniform non-rigid mechanical property. However, the synergistic effect of material removal between organic cores and inorganic shells of composite abrasives is ambiguous. In this work, oxide-CMP performances of various slurries, containing polystyrene (PS) spheres, solid abrasives (SiO2 or CeO2), mixed abrasives ((PS + SiO2) or (PS + CeO2)), core/shell composites (PS/SiO2 or PS/CeO2), were investigated by atomic force microscopy. Experiment results indicated that the surfaces polished by composite abrasives exhibited lower surface roughness, fewer scratches as well as lower topographical variations than those by other type of abrasives. The core/shell structure of composite abrasives plays an important role in improving CMP behavior. Moreover, the organic cores are mainly beneficial to decrease surface roughness and mechanical damages, and the inorganic shells are in favor of improving material removal rate

  8. Progress and perspectives of quantitative structure-activity relationships used for ecological risk assessment of toxic organic compounds

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Structure-activity relationship (SAR) and quantitative structure-activity relationship (QSAR), collec- tively referred to as (Q)SARs, play an important role in ecological risk assessment (ERA) of organic chemicals. (Q)SARs can fill the data gap for physical-chemical, environmental behavioral and ecotoxicological parameters of organic compounds; they can decrease experimental expenses and reduce the extent of experimental testing (especially animal testing); they can also be used to assess the uncertainty of the experimental data. With the development for several decades, (Q)SARs in envi- ronmental sciences show three features: application orientation, multidisciplinary integration, and in- telligence. Progress of (Q)SAR technology for ERA of toxic organic compounds, including endpoint selection and mathematic methods for establishing simple, transparent, easily interpretable and portable (Q)SAR models, is reviewed. The recent development on defining application domains and diagnosing outliers is summarized. Model characterization with respect to goodness-of-fit, stability and predictive power is specially presented. The purpose of the review is to promote the development of (Q)SARs orientated to ERA of organic chemicals.

  9. 3D bioprinting matrices with controlled pore structure and release function guide in vitro self-organization of sweat gland

    Science.gov (United States)

    Liu, Nanbo; Huang, Sha; Yao, Bin; Xie, Jiangfan; Wu, Xu; Fu, Xiaobing

    2016-01-01

    3D bioprinting matrices are novel platforms for tissue regeneration. Tissue self-organization is a critical process during regeneration that implies the features of organogenesis. However, it is not clear from the current evidences whether 3D printed construct plays a role in guiding tissue self-organization in vitro. Based on our previous study, we bioprinted a 3D matrix as the restrictive niche for direct sweat gland differentiation of epidermal progenitors by different pore structure (300-μm or 400-μm nozzle diameters printed) and reported a long-term gradual transition of differentiated cells into glandular morphogenesis occurs within the 3D construct in vitro. At the initial 14-day culture, an accelerated cell differentiation was achieved with inductive cues released along with gelatin reduction. After protein release completed, the 3D construct guide the self-organized formation of sweat gland tissues, which is similar to that of the natural developmental process. However, glandular morphogenesis was only observed in 300-μm–printed constructs. In the absence of 3D architectural support, glandular morphogenesis was not occurred. This striking finding made us to identify a previously unknown role of the 3D-printed structure in glandular tissue regeneration, and this self-organizing strategy can be applied to forming other tissues in vitro. PMID:27694985

  10. Synergetic effect of organic cores and inorganic shells for core/shell structured composite abrasives for chemical mechanical planarization

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yang, E-mail: cy.jpu@126.com [School of Materials Science and Engineering, Changzhou University, Changzhou, Jiangsu 213164 (China); Li, Zhina [School of Materials Science and Engineering, Changzhou University, Changzhou, Jiangsu 213164 (China); Miao, Naiming [School of Mechanical Engineering, Changzhou University, Changzhou, Jiangsu 213016 (China)

    2014-09-30

    Highlights: • The damage-free polishing mechanism of core/shell composite abrasive was explored. • The organic core is help to decrease surface roughness and mechanical damages. • The inorganic shell is in favor of improving material removal rate. • The enhanced CMP behavior is due to the synergistic effect between core and shell. - Abstract: Core/shell structured organic/inorganic composite microspheres has an important potential application in efficient and damage-free chemical mechanical planarization/polishing (CMP) as a kind of novel abrasive due to its uniform non-rigid mechanical property. However, the synergistic effect of material removal between organic cores and inorganic shells of composite abrasives is ambiguous. In this work, oxide-CMP performances of various slurries, containing polystyrene (PS) spheres, solid abrasives (SiO{sub 2} or CeO{sub 2}), mixed abrasives ((PS + SiO{sub 2}) or (PS + CeO{sub 2})), core/shell composites (PS/SiO{sub 2} or PS/CeO{sub 2}), were investigated by atomic force microscopy. Experiment results indicated that the surfaces polished by composite abrasives exhibited lower surface roughness, fewer scratches as well as lower topographical variations than those by other type of abrasives. The core/shell structure of composite abrasives plays an important role in improving CMP behavior. Moreover, the organic cores are mainly beneficial to decrease surface roughness and mechanical damages, and the inorganic shells are in favor of improving material removal rate.

  11. Progress and perspectives of quantitative structure-activity relationships used for ecological risk assessment of toxic organic compounds

    Institute of Scientific and Technical Information of China (English)

    CHEN JingWen; LI XueHua; YU HaiYing; WANG YaNan; QIAO XianLiang

    2008-01-01

    Structure-activity relationship (SAR) and quantitative structure-activity relationship (QSAR), collec-tively referred to as (Q)SARs, play an important role in ecological risk assessment (ERA) of organic chemicals. (Q)SARs can fill the data gap for physical-chemical, environmental behavioral and ecotoxicological parameters of organic compounds; they can decrease experimental expenses and reduce the extent of experimental testing (especially animal testing); they can also be used to assess the uncertainty of the experimental data. With the development for several decades, (Q)SARs in envi-ronmental sciences show three features: application orientation, multidisciplinary integration, and in-telligence. Progress of (Q)SAR technology for ERA of toxic organic compounds, including endpoint selection and mathematic methods for establishing simple, transparent, easily interpretable and portable (Q)SAR models, is reviewed. The recent development on defining application domains and diagnosing outliers is summarized. Model characterization with respect to goodness-of-fit, stability and predictive power is specially presented. The purpose of the review is to promote the development of (Q)SARs orientated to ERA of organic chemicals.

  12. A comparative study of the structural organization of spheres derived from the adult human subventricular zone and glioblastoma biopsies

    Energy Technology Data Exchange (ETDEWEB)

    Vik-Mo, Einar Osland, E-mail: e.o.vik-mo@medisin.uio.no [Vilhelm Magnus Laboratory for Neurosurgical Research, Institute for Surgical Research, Oslo University Hospital, Oslo (Norway); Department of Neurosurgery, Oslo University Hospital, Oslo (Norway); Sandberg, Cecilie [Vilhelm Magnus Laboratory for Neurosurgical Research, Institute for Surgical Research, Oslo University Hospital, Oslo (Norway); Joel, Mrinal [Vilhelm Magnus Laboratory for Neurosurgical Research, Institute for Surgical Research, Oslo University Hospital, Oslo (Norway); Department of Physiology, Institute of Basic Medical Sciences, University of Oslo (Norway); Stangeland, Biljana [Vilhelm Magnus Laboratory for Neurosurgical Research, Institute for Surgical Research, Oslo University Hospital, Oslo (Norway); Watanabe, Yasuhiro [Division of Neurology, Department of Brain and Neurosciences, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago 683-8504 (Japan); Mackay-Sim, Alan [National Centre for Adult Stem Cell Research, Eskitis Institute for Cell and Molecular Therapies, Griffith University, Brisbane, QLD 4111 (Australia); Moe, Morten Carstens [Center for Eye Research, Department of Ophthalmology, Oslo University Hospital, Oslo (Norway); Murrell, Wayne [Vilhelm Magnus Laboratory for Neurosurgical Research, Institute for Surgical Research, Oslo University Hospital, Oslo (Norway); Langmoen, Iver Arne [Vilhelm Magnus Laboratory for Neurosurgical Research, Institute for Surgical Research, Oslo University Hospital, Oslo (Norway); Department of Neurosurgery, Oslo University Hospital, Oslo (Norway)

    2011-04-15

    Sphere forming assays have been useful to enrich for stem like cells in a range of tumors. The robustness of this system contrasts the difficulties in defining a stem cell population based on cell surface markers. We have undertaken a study to describe the cellular and organizational composition of tumorspheres, directly comparing these to neurospheres derived from the adult human subventricular zone (SVZ). Primary cell cultures from brain tumors were found to contain variable fractions of cells positive for tumor stem cell markers (CD133 (2-93%)/SSEA1 (3-15%)/CXCR4 (1-72%)). All cultures produced tumors upon xenografting. Tumorspheres contained a heterogeneous population of cells, but were structurally organized with stem cell markers present at the core of spheres, with markers of more mature glial progenitors and astrocytes at more peripheral location. Ultrastructural studies showed that tumorspheres contained a higher fraction of electron dense cells in the core than the periphery (36% and 19%, respectively). Neurospheres also contained a heterogeneous cell population, but did not have an organization similar to tumorspheres. Although tumorspheres clearly display irregular and neoplastic cells, they establish an organized structure with an outward gradient of differentiation. We suggest that this organization is central in maintaining the tumor stem cell pool.

  13. Estimation and Prediction of Bioconcentration Factors of Nonionic Organic Chemicals in Fish by Electrotopological State Indices and Structural Parameter

    Institute of Scientific and Technical Information of China (English)

    FENG Chang-Jun; YANG Wei-Hua; MU Lai-Long

    2008-01-01

    Based on the characteristics of atom types, Hall's electrotopological state indices (En) are calculated for 165 nonionic organic compounds. On the basis of the characteristics of substituent and conjugated matrix, a novel molecular structure parameter (G) is defined and calcu- lated for 165 molecules in this paper. En and G show good structural selectivity for organic molecules. G, a satisfactory relationship between bioconcentration factor (BCF) and En, is expressed as: lgBCF = -0.283 + 1.246G + 0.079E42 + 0.351E9 - 0.063E17 (n' = 122, R = 0.967, F = 425.636, s = 0.394), which could provide estimation and prediction for the lgBCF of nonionic organic chemicals. Furthermore, the model is examined to validate overall robustness with Jackknife tests, and the independent variables in model do not exist cross correlation with VIF. All these regression results show that the new parameter G and electrotopological state index have good rationality and efficiency. It is concluded that the En and G will be used widely in quantitative structure-property/activity relationship (QSPR/QSAR) research.

  14. Synthesis,structure and luminescence properties of metal-organic frameworks based on benzo-bis(imidazole)

    Institute of Scientific and Technical Information of China (English)

    YIN XinBo; SONG YuNa; WANG Yang; ZHANG LiJuan; LI QiaoWei

    2014-01-01

    Metal-organic frameworks(MOFs)constructed from conjugated organic ligands are candidates for hybrid photoactive materials with potential applications.Compared to that from the ligands only,the intensity and wavelength of the luminescence could be tuned after they were incorporated in extended framework.In this report,by using an organic ligand with azolate moiety,benzo-bis(imidazole)(H2BBI),we synthesized two new MOF structures.Framework 1([Co(H2BBI)(DMSO)2Cl2]n,DMSO=dimethyl sulfoxide),constructed from tetrahedral Co(II)and H2BBI,exhibits zigzag 1D structure.Meanwhile,framework 2([Cu2(H2BBI)3(DMSO)6(NO3)4]n),a layered structure with hcb topology,was assembled from tetragonal pyramidal Cu(II)and H2BBI.Furthermore,2 exhibits strong luminescence emission(ex=280 nm).A blue shift of 40 nm(from 359 nm to 319 nm)was observed in framework 2 compared to the free ligand,which could be explained by the ligand-to-metal charge transfer in the network.

  15. Soil structure and microbial activity dynamics in 20-month field-incubated organic-amended soils

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Schjønning, Per; Møldrup, Per;

    2014-01-01

    to determine compressive strength. During incubation, the amount of WDC depended on soil carbon content while the trends correlated with moisture content. Organic amendment only yielded modest decreases (mean of 14% across all sampling times and soils) in WDC, but it was sufficient to stimulate the...... microbial community (65–100% increase in FDA). Incubation led to significant macroaggregate formation (>2 mm) for all soils. Friability and strength of newly-formed aggregates were negatively correlated with clay content and carbon content, respectively. Soil workability was best for the kaolinite-rich soil...... and poorest for the smectite-rich soil; for illitic soils, workability increased with increasing organic carbon content. Organic amendment decreased the compression susceptibility of intact, incubated samples at smaller stress values (<200 kPa)....

  16. Optimizing The Organic/Inorganic Barrier Structure For Flexible Plastic Substrate Encapsulation

    Directory of Open Access Journals (Sweden)

    Yi-Chiuan Lin

    2012-07-01

    Full Text Available A multilayered barrier structure stacked with organosilicon and silicon oxide (SiOx films consecutively prepared using plasma-enhanced chemical vapor deposition (PECVD was developed to encapsulate flexible plastic substrate. The evolution on the residual internal stress, structural quality of the organosilicon/SiOx multilayered structure as well as its adhesion to the substrate were found to correlate closely with the thickness of the inset organosilicon layer. Due to the significant discrepancy in the thermal expansion coefficient between the substrate and SiOx film, the thickness of the organosilicon layer deposited onto the substrate and SiOx film thus was crucial to optimize the barrier property of the organosilicon/SiOx structure. The organosilicon/SiOx barrier structure possessed a lowest residual compressive stress and quality adhesion to the substrate was achieved from engineering the organosilicon layer thickness in the multilayered structure. The relaxation of the residual internal stress in the barrier structure led to a dense SiOx film as a consequence of the enhancement in the Si-O-Si networks and thereby resulted in the reduction of the water vapor permeation. Accordingly, a water vapor transmission rate (WVTR below 1 × 10-2 g/m2 /day being potential for the application on the flexible optoelectronic device packaging was achievable from the 3-pairs organosilicon/SiOx multilayered structure deposited onto the polyethylene terephthalate (PET substrate.

  17. Interfacial Structures and Properties of Organic Materials for Biosensors: An Overview

    Directory of Open Access Journals (Sweden)

    Yan Zhou

    2012-11-01

    Full Text Available The capabilities of biosensors for bio-environmental monitoring have profound influences on medical, pharmaceutical, and environmental applications. This paper provides an overview on the background and applications of the state-of-the-art biosensors. Different types of biosensors are summarized and sensing mechanisms are discussed. A review of organic materials used in biosensors is given. Specifically, this review focuses on self-assembled monolayers (SAM due to their high sensitivity and high versatility. The kinetics, chemistry, and the immobilization strategies of biomolecules are discussed. Other representative organic materials, such as graphene, carbon nanotubes (CNTs, and conductive polymers are also introduced in this review.

  18. High Performance Work Systems as an Enabling Structure for Self-organized Learning Processes

    Directory of Open Access Journals (Sweden)

    Thomas Wallner

    2012-11-01

    Full Text Available High Performance Work Systems (HPWSs as a new way of organizing work in general and of production work in particular provide an environment, where self-organized learning processes are enabled and fostered. In an extensive research project in 2 major Austrian manufacturing companies we currently investigate the applicability and the effects of HPWS including issues of learning and knowledge management. In this contribution we present the results of the first phase of this project discussing early empirical findings of an exploratory nature.

  19. Integrated Bioenergy and Food Production—A German Survey on Structure and Developments of Anaerobic Digestion in Organic Farming Systems

    Directory of Open Access Journals (Sweden)

    Benjamin Blumenstein

    2015-08-01

    Full Text Available Rising global energy needs and limited fossil fuel reserves have led to increased use of renewable energies. In Germany, this has entailed massive exploitation of agricultural biomass for biogas generation, associated with unsustainable farming practices. Organic agriculture not only reduces negative environmental impacts, organic farmers were also prime movers in anaerobic digestion (AD in Germany. This study’s aim was to identify the structure, development, and characteristics of biogas production associated with organic farming systems in order to estimate further development, as well as energetic and associated agronomic potentials. Surveys were conducted among organic farms with AD technology. 144 biogas plants could be included in the analysis. Total installed electrical capacity was 30.8 MWel, accounting for only 0.8% of the total installed electrical capacity in the German biogas sector. Recently, larger plant types (>250 kWel with increased use of (also purchased energy crops have emerged. Farmers noticed increases in yields (22% on average and quality of cash crops in arable farming through integrated biogas production. In conclusion, although the share of AD in organic farming is relatively small it can provide various complementary socio-ecological benefits such as the enhancement of food output through digestate fertilization without additional need for land, while simultaneously reducing greenhouse gas emissions from livestock manures and soils. However, to achieve this eco-functional intensification, AD systems and their management have to be well adapted to farm size and production focus and based primarily on residue biomass.

  20. 3D fluorescence-based characterization of dissolved organic matter components and their impact on soil-structure stability indices

    Science.gov (United States)

    Levy, Guy; Lordian, Anna; Borisover, Mikhail

    2010-05-01

    Stable soil aggregates and structure are usually associated with increased levels of soil organic matter. A significant fraction of the latter is comprised of humic substances (HS). Opposing findings on the contribution of HS to both stabilization and increased dispersivity of soil aggregates have been reported; these findings could be related to the heterogeneity in the chemical composition of the HS. The objectives of this research were: (i) to characterize the compositional heterogeneity of HS and dissolved organic matter (DOM) in soil solutions, (ii) to evaluate the relations between general soil properties (e.g., organic matter, clay and calcium carbonate content, cation exchange capacity) and concentration and composition of DOM and HS in soil solution, and (iii) to examine the relationships between properties associated with soil structure such as aggregate stability and hydraulic conductivity and the composition of DOM and HS. The composition of HS and DOM in aqueous extracts, obtained from samples collected from cultivated fields of four Israeli soils (loamy sand, loam, sandy clay and clay), was characterized and quantified using 3D fluorescence (and UV-absorption) spectroscopy together with parallel factor analysis (PARAFAC) supported by dissolved organic carbon (DOC) measurements. Variability in the HS/DOM composition was obtained by including soils with a different history of irrigation, i.e. irrigated by fresh water and by treated wastewater. PARAFAC analysis provided scores proportional to concentrations of three major fluorescent DOM components, two were considered to represent HS and the third to represent proteinous matter (containing tryptophan). Soil structure had been characterized by saturated hydraulic conductivity and an index for aggregate stability. PARAFAC analysis demonstrated that concentrations of fluorescent DOM components in aqueous extracts were influenced by the type of water used for irrigation. This influence was distinctly