Cooperative and submolecular dissipation mechanisms of sliding friction in complex organic systems.

Science.gov (United States)

Knorr, Daniel B; Gray, Tomoko O; Overney, René M

2008-08-21

Energy dissipation in single asperity sliding friction was directly linked to submolecular modes of mobility by intrinsic friction analysis, involving time-temperature superposition along with thermodynamic stress and reaction rate models. Thereby, polystyrene served as a representative tribological sample for organic and amorphous complex systems. This study reveals the significance of surface and subsurface (alpha-, beta-, and gamma-) relaxational modes, which couple under appropriate external conditions (load, temperature, and rate) with shear induced disturbances, and thus gives rise to material specific frictional dissipation. At low pressures and temperatures below the glass transition point, the phenyl pendant side groups of polystyrene, known for their preferential orientation at the free surface, were noticed to be the primary channel for dissipation of kinetic sliding-energy. While this process was found to be truly enthalpic (activation energy of 8 kcalmol), energy dissipation was shown to possess both enthalpic and cooperative entropic contributions above the loading capacity of the surface phenyl groups (9.9 kcalmol) or above the glass transition. Apparent Arrhenius activation energies of frictional dissipation of 22 and 90 kcalmol, respectively, and cooperative contributions up to 80% were found. As such, this study highlights issues critical to organic lubricant design, i.e., the intrinsic enthalpic activation barriers of mobile linker groups, the evaluation of cooperative mobility phenomena, and critical tribological parameters to access or avoid coupling between shear disturbances and molecular actuators.

The necessity of strengthening the cooperation between tissue banks and organ transplant organizations at national, regional, and international levels.

Science.gov (United States)

Morales Pedraza, Jorge

2013-12-01

The donation of tissues and organs increases significantly when tissue banks and organ transplant organizations work together in the procurement of organs and tissues at donor sources (hospitals, coroners system, organ procurement agencies, and funeral homes, among others). To achieve this important goal, national competent health authorities should considered the establishment of a mechanism that promote the widest possible cooperation between tissue banks and organ transplant organizations with hospitals, research medical institutions, universities, and other medical institutions and facilities. One of the issues that can facilitate this cooperation is the establishment of a coding and traceability system that could identify all tissues and organs used in transplant activities carried out in any country. The promotion of national, regional, and international cooperation between tissue banks and organ transplant organizations would enable the sharing of relevant information that could be important for medical practice and scientific studies carried out by many countries, particularly for those countries with a weak health care system.

Exciton confinement in organic dendrimer quantum wells for opto-electronic applications

Science.gov (United States)

Lupton, J. M.; Samuel, I. D. W.; Burn, P. L.; Mukamel, S.

2002-01-01

Organic dendrimers are a fascinating new class of materials for opto-electronic applications. We present coupled electronic oscillator calculations on novel nanoscale conjugated dendrimers for use in organic light-emitting diodes. Strong confinement of excitations at the center of the dendrimers is observed, which accounts for the dependence of intermolecular interactions and charge transport on the degree of branching of the dendrimer. The calculated absorption spectra are in excellent agreement with the measured data and show that benzene rings are shared between excitations on the linear segments of the hyperbranched molecules. The coupled electronic oscillator approach is ideally suited to treat large dendritic molecules.

Hormonal mechanisms of cooperative behaviour

Science.gov (United States)

Soares, Marta C.; Bshary, Redouan; Fusani, Leonida; Goymann, Wolfgang; Hau, Michaela; Hirschenhauser, Katharina; Oliveira, Rui F.

2010-01-01

Research on the diversity, evolution and stability of cooperative behaviour has generated a considerable body of work. As concepts simplify the real world, theoretical solutions are typically also simple. Real behaviour, in contrast, is often much more diverse. Such diversity, which is increasingly acknowledged to help in stabilizing cooperative outcomes, warrants detailed research about the proximate mechanisms underlying decision-making. Our aim here is to focus on the potential role of neuroendocrine mechanisms on the regulation of the expression of cooperative behaviour in vertebrates. We first provide a brief introduction into the neuroendocrine basis of social behaviour. We then evaluate how hormones may influence known cognitive modules that are involved in decision-making processes that may lead to cooperative behaviour. Based on this evaluation, we will discuss specific examples of how hormones may contribute to the variability of cooperative behaviour at three different levels: (i) within an individual; (ii) between individuals and (iii) between species. We hope that these ideas spur increased research on the behavioural endocrinology of cooperation. PMID:20679116

Electronic Processes at Organic−Organic Interfaces: Insight from Modeling and Implications for Opto-electronic Devices †

KAUST Repository

Beljonne, David; Cornil, Jérôme; Muccioli, Luca; Zannoni, Claudio; Brédas, Jean-Luc; Castet, Frédéric

2011-01-01

We report on the recent progress achieved in modeling the electronic processes that take place at interfaces between π-conjugated materials in organic opto-electronic devices. First, we provide a critical overview of the current computational

Theory of Regression Apple Professional Cooperation Organization Research

OpenAIRE

Ouyang Bin

2013-01-01

In view of the enterprise ecological apple manor a variety of problems of existence, put forward to the enterprise management transformation, achieve enterprise, collective, individual integrated operation management and the use of regression mathematical model on apple professional cooperation organization analysis. Through the example, Apple professional economic cooperation organization innovation model of the input output ratio than the rural economic cooperation organization is much high...

Optoelectronics of Molecules and Polymers

CERN Document Server

Moliton, André

2006-01-01

Optoelectronic devices are being developed at an extraordinary rate. Organic light emitting diodes, photovoltaic devices and electro-optical modulators are pivotal to the future of displays, photosensors and solar cells, and communication technologies. This book details the theories underlying the relevant mechanisms in organic materials and covers, at a basic level, how the organic components are made. The first part of this book introduces the fundamental theories used to detail ordered solids and localised energy levels. The methods used to determine energy levels in perfectly ordered molecular and macromolecular systems are discussed, making sure that the effects of quasi-particles are not missed. The function of excitons and their transfer between two molecules are studied, and the problems associated with interfaces and charge injection into resistive media are presented. The second part details technological aspects such as the fabrication of devices based on organic materials by dry etching. The princ...

Is cooperation viable in mobile organisms? Simple Walk Away rule favors the evolution of cooperation in groups

Science.gov (United States)

Aktipis, C. Athena

2011-01-01

The evolution of cooperation through partner choice mechanisms is often thought to involve relatively complex cognitive abilities. Using agent-based simulations I model a simple partner choice rule, the ‘Walk Away’ rule, where individuals stay in groups that provide higher returns (by virtue of having more cooperators), and ‘Walk Away’ from groups providing low returns. Implementing this conditional movement rule in a public goods game leads to a number of interesting findings: 1) cooperators have a selective advantage when thresholds are high, corresponding to low tolerance for defectors, 2) high thresholds lead to high initial rates of movement and low final rates of movement (after selection), and 3) as cooperation is selected, the population undergoes a spatial transition from high migration (and a many small and ephemeral groups) to low migration (and large and stable groups). These results suggest that the very simple ‘Walk Away’ rule of leaving uncooperative groups can favor the evolution of cooperation, and that cooperation can evolve in populations in which individuals are able to move in response to local social conditions. A diverse array of organisms are able to leave degraded physical or social environments. The ubiquitous nature of conditional movement suggests that ‘Walk Away’ dynamics may play an important role in the evolution of social behavior in both cognitively complex and cognitively simple organisms. PMID:21666771

Fully coupled opto-electronic modelling of organic solar cells

Energy Technology Data Exchange (ETDEWEB)

Reinke, Nils A.; Haeusermann, Roger; Huber, Evelyne; Moos, Michael [ZHAW, Institute of Comp. Physics (Germany); Flatz, Thomas [Fluxim AG (Switzerland); Ruhstaller, Beat [ZHAW, Institute of Comp. Physics (Germany); Fluxim AG (Switzerland)

2009-07-01

Record solar power conversion efficiencies of up to 5.5 % for single junction organic solar cells (OSC) are encouraging but still inferior to values of inorganic solar cells. For further progress, a detailed analysis of the mechanisms that limit the external quantum efficiency is crucial. It is widely believed that the device physics of OSCs can be reduced to the processes, which take place at the donor/acceptor-interface. Neglecting transport, trapping and ejection of charge carriers at the electrodes raises the question of the universality of such a simplification. In this study we present a fully coupled opto-electronic simulator, which calculates the spatial and spectral photon flux density inside the OSC, the formation of the charge transfer state and its dissociation into free charge carriers. Our simulator solves the drift- diffusion equations for the generated charge carriers as well as their ejection at the electrodes. Our results are in good agreement with both steady-state and transient OSC characteristics. We address the influence of physical quantities such as the optical properties, film-thicknesses, the recombination rate and charge carrier mobilities on performance figures. For instance the short circuit current can be enhanced by 15% to 25% when using a silver instead of an aluminium cathode. Our simulations lead to rules of thumb, which help to optimise a given OSC structure.

Optoelectronic Mounting Structure

Science.gov (United States)

Anderson, Gene R.; Armendariz, Marcelino G.; Baca, Johnny R. F.; Bryan, Robert P.; Carson, Richard F.; Chu, Dahwey; Duckett, III, Edwin B.; McCormick, Frederick B.; Peterson, David W.; Peterson, Gary D.; Reber, Cathleen A.; Reysen, Bill H.

2004-10-05

An optoelectronic mounting structure is provided that may be used in conjunction with an optical transmitter, receiver or transceiver module. The mounting structure may be a flexible printed circuit board. Thermal vias or heat pipes in the head region may transmit heat from the mounting structure to the heat spreader. The heat spreader may provide mechanical rigidity or stiffness to the heat region. In another embodiment, an electrical contact and ground plane may pass along a surface of the head region so as to provide an electrical contact path to the optoelectronic devices and limit electromagnetic interference. In yet another embodiment, a window may be formed in the head region of the mounting structure so as to provide access to the heat spreader. Optoelectronic devices may be adapted to the heat spreader in such a manner that the devices are accessible through the window in the mounting structure.

Recommendations for Optimizing Internal Management Mechanism of Farmers’ Specialized Cooperatives

Institute of Scientific and Technical Information of China (English)

Jingxiao; CHEN

2016-01-01

Based on the survey of 38 farmers’ specialized cooperatives in Hubei Province,this paper analyzed existing problems in internal management mechanism of cooperatives,including widespread problem of centralized control,imperfect supervision mechanism,lack of effective incentive mechanism,insufficient specialized personnel,and limited participation of cooperative members in management. It elaborated causes for these problems from the perspective of practice. Finally,it came up with recommendations for optimizing farmers’ specialized cooperatives: building democratic decision making mechanism with coordination of cooperative members and able personnel,establishing supervision mechanism suitable for self demands,improving internal incentive mechanism,establishing talent introduction and cultivation mechanism in proper time,and strengthening internal member management of cooperatives.

Mild Conditions for Deuteration of Primary and Secondary Arylamines for the Synthesis of Deuterated Optoelectronic Organic Molecules

Directory of Open Access Journals (Sweden)

Anwen M. Krause-Heuer

2014-11-01

Full Text Available Deuterated arylamines demonstrate great potential for use in optoelectronic devices, but their widespread utility requires a method for large-scale synthesis. The incorporation of these deuterated materials into optoelectronic devices also provides the opportunity for studies of the functioning device using neutron reflectometry based on the difference in the scattering length density between protonated and deuterated compounds. Here we report mild deuteration conditions utilising standard laboratory glassware for the deuteration of: diphenylamine, N-phenylnaphthylamine, N-phenyl-o-phenylenediamine and 1-naphthylamine (via H/D exchange in D2O at 80 °C, catalysed by Pt/C and Pd/C. These conditions were not successful in the deuteration of triphenylamine or N,N-dimethylaniline, suggesting that these mild conditions are not suitable for the deuteration of tertiary arylamines, but are likely to be applicable for the deuteration of other primary and secondary arylamines. The deuterated arylamines can then be used for synthesis of larger organic molecules or polymers with optoelectronic applications.

Five Rules for the Evolution of Cooperation

Science.gov (United States)

Nowak, Martin A.

2006-12-01

Cooperation is needed for evolution to construct new levels of organization. Genomes, cells, multicellular organisms, social insects, and human society are all based on cooperation. Cooperation means that selfish replicators forgo some of their reproductive potential to help one another. But natural selection implies competition and therefore opposes cooperation unless a specific mechanism is at work. Here I discuss five mechanisms for the evolution of cooperation: kin selection, direct reciprocity, indirect reciprocity, network reciprocity, and group selection. For each mechanism, a simple rule is derived that specifies whether natural selection can lead to cooperation.

Optoelectronic properties of four azobenzene-based iminopyridine ligands for photovoltaic application

Directory of Open Access Journals (Sweden)

Aziz El alamy

2017-11-01

Full Text Available Because of organic π-conjugated materials’ optoelectronic properties and potential applications in a wide range of electronic and optoelectronic devices, such as organic solar cells, these materials, including both polymers and oligomers, have been widely studied in recent years. This work reposts a theoretical study using the DFT method on four azobenzene-based iminopyridines. The theoretical ground-state geometry, electronic structure and optoelectronic parameters (highest occupied molecular orbital (HOMO, lowest unoccupied molecular orbital (LUMO energy levels, open-circuit voltage (Voc and oscillator strengths (O.S of the studied molecules were obtained using the density functional theory (DFT and time-dependent (TDDFT approaches. The effects of the structure length and substituents on the geometric and optoelectronic properties of these materials are discussed to investigate the relationship between the molecular structure and the optoelectronic properties. The results of this study are consistent with the experimental ones and suggest that these materials as good candidates for use in photovoltaic devices. Keywords: π-conjugated materials, azobenzene, optoelectronic properties, DFT calculations, HOMO-LUMO gap

Cooperation and Conflict: a Law and Economics Analysis of Meta-Organizations

NARCIS (Netherlands)

M. Kerk (Maximilian)

2017-01-01

markdownabstractOver the second part of the twentieth century inter-firm cooperations have become an increasingly popular phenomenon. These inter-firm cooperations often play out in the form of meta-organizations, which are organizations that are composed of the cooperating organizations. This

Fragility and cooperativity concepts in hydrogen-bonded organic glasses

International Nuclear Information System (INIS)

Delpouve, N.; Vuillequez, A.; Saiter, A.; Youssef, B.; Saiter, J.M.

2012-01-01

Molecular dynamics at the glass transition of three lactose/oil glassy systems have been investigated according to the cooperativity and fragility approaches. From Donth's approach, the cooperativity length is estimated by modulated temperature calorimetric measurements. Results reveal that modification of the disaccharide by oil leads to increase the disorder degree in the lactose, the size of the cooperative domains and the fragility index. These particular hydrogen-bonded organic glasses follow the general tendency observed on organic and inorganic polymers: the higher the cooperativity length, the higher the value of the fragility index at T g .

Photonic Structure-Integrated Two-Dimensional Material Optoelectronics

Directory of Open Access Journals (Sweden)

Tianjiao Wang

2016-12-01

Full Text Available The rapid development and unique properties of two-dimensional (2D materials, such as graphene, phosphorene and transition metal dichalcogenides enable them to become intriguing candidates for future optoelectronic applications. To maximize the potential of 2D material-based optoelectronics, various photonic structures are integrated to form photonic structure/2D material hybrid systems so that the device performance can be manipulated in controllable ways. Here, we first introduce the photocurrent-generation mechanisms of 2D material-based optoelectronics and their performance. We then offer an overview and evaluation of the state-of-the-art of hybrid systems, where 2D material optoelectronics are integrated with photonic structures, especially plasmonic nanostructures, photonic waveguides and crystals. By combining with those photonic structures, the performance of 2D material optoelectronics can be further enhanced, and on the other side, a high-performance modulator can be achieved by electrostatically tuning 2D materials. Finally, 2D material-based photodetector can also become an efficient probe to learn the light-matter interactions of photonic structures. Those hybrid systems combine the advantages of 2D materials and photonic structures, providing further capacity for high-performance optoelectronics.

Recent advances in flexible and wearable organic optoelectronic devices

Science.gov (United States)

Zhu, Hong; Shen, Yang; Li, Yanqing; Tang, Jianxin

2018-01-01

Flexible and wearable optoelectronic devices have been developing to a new stage due to their unique capacity for the possibility of a variety of wearable intelligent electronics, including bendable smartphones, foldable touch screens and antennas, paper-like displays, and curved and flexible solid-state lighting devices. Before extensive commercial applications, some issues still have to be solved for flexible and wearable optoelectronic devices. In this regard, this review concludes the newly emerging flexible substrate materials, transparent conductive electrodes, device architectures and light manipulation methods. Examples of these components applied for various kinds of devices are also summarized. Finally, perspectives about the bright future of flexible and wearable electronic devices are proposed. Project supported by the Ministry of Science and Technology of China (No. 2016YFB0400700).

11 CFR 114.7 - Membership organizations, cooperatives, or corporations without capital stock.

Science.gov (United States)

2010-01-01

... organizational structure. (j) A membership organization, including a trade association, cooperative, or... 11 Federal Elections 1 2010-01-01 2010-01-01 false Membership organizations, cooperatives, or... CORPORATE AND LABOR ORGANIZATION ACTIVITY § 114.7 Membership organizations, cooperatives, or corporations...

Fragility and cooperativity concepts in hydrogen-bonded organic glasses

Energy Technology Data Exchange (ETDEWEB)

Delpouve, N., E-mail: delpouve.nicolas@gmail.com [AMME-LECAP EA 4528 International Laboratory, University of Rouen, Avenue de l' Universite BP 12, 76801 Saint Etienne du Rouvray (France); Vuillequez, A.; Saiter, A.; Youssef, B.; Saiter, J.M. [AMME-LECAP EA 4528 International Laboratory, University of Rouen, Avenue de l' Universite BP 12, 76801 Saint Etienne du Rouvray (France)

2012-09-01

Molecular dynamics at the glass transition of three lactose/oil glassy systems have been investigated according to the cooperativity and fragility approaches. From Donth's approach, the cooperativity length is estimated by modulated temperature calorimetric measurements. Results reveal that modification of the disaccharide by oil leads to increase the disorder degree in the lactose, the size of the cooperative domains and the fragility index. These particular hydrogen-bonded organic glasses follow the general tendency observed on organic and inorganic polymers: the higher the cooperativity length, the higher the value of the fragility index at T{sub g}.

Rotator side chains trigger cooperative transition for shape and function memory effect in organic semiconductors.

Science.gov (United States)

Chung, Hyunjoong; Dudenko, Dmytro; Zhang, Fengjiao; D'Avino, Gabriele; Ruzié, Christian; Richard, Audrey; Schweicher, Guillaume; Cornil, Jérôme; Beljonne, David; Geerts, Yves; Diao, Ying

2018-01-18

Martensitic transition is a solid-state phase transition involving cooperative movement of atoms, mostly studied in metallurgy. The main characteristics are low transition barrier, ultrafast kinetics, and structural reversibility. They are rarely observed in molecular crystals, and hence the origin and mechanism are largely unexplored. Here we report the discovery of martensitic transition in single crystals of two different organic semiconductors. In situ microscopy, single-crystal X-ray diffraction, Raman and nuclear magnetic resonance spectroscopy, and molecular simulations combined indicate that the rotating bulky side chains trigger cooperative transition. Cooperativity enables shape memory effect in single crystals and function memory effect in thin film transistors. We establish a molecular design rule to trigger martensitic transition in organic semiconductors, showing promise for designing next-generation smart multifunctional materials.

26 CFR 1.501(e)-1 - Cooperative hospital service organizations.

Science.gov (United States)

2010-04-01

... operates laundry services for its patron-hospitals. This cooperative organization does not meet the requirements of this paragraph because it performs laundry services not specified in this paragraph. (d) Patron... 26 Internal Revenue 7 2010-04-01 2010-04-01 true Cooperative hospital service organizations. 1.501...

Integrated silicon optoelectronics

CERN Document Server

Zimmermann, Horst

2000-01-01

'Integrated Silicon Optoelectronics'assembles optoelectronics and microelectronics The book concentrates on silicon as the major basis of modern semiconductor devices and circuits Starting from the basics of optical emission and absorption and from the device physics of photodetectors, the aspects of the integration of photodetectors in modern bipolar, CMOS, and BiCMOS technologies are discussed Detailed descriptions of fabrication technologies and applications of optoelectronic integrated circuits are included The book, furthermore, contains a review of the state of research on eagerly expected silicon light emitters In order to cover the topic of the book comprehensively, integrated waveguides, gratings, and optoelectronic power devices are included in addition Numerous elaborate illustrations promote an easy comprehension 'Integrated Silicon Optoelectronics'will be of value to engineers, physicists, and scientists in industry and at universities The book is also recommendable for graduate students speciali...

Study of Mechanisms for Development and Strengthening of Water User Cooperatives (Case Study of Aras River Basin: Application of AHP Method

Directory of Open Access Journals (Sweden)

Rohallah maghabl

2014-06-01

Full Text Available Water user cooperatives were formed due to consideration to people's empowerment and participation in water investment and management. The purpose of this study was to investigate the mechanisms of development and strengthening of water user cooperatives in the Aras River Basin. The study population consisted of the management board members of the water user cooperatives in the Aras Basin in the year 2012. Respondents were selected by purposeful stratified sampling method. Having the data collected by interviews and questionnaires, the Analytic Hierarchy Process (through the software Expert Choice 11 was used to prioritize mechanisms for the development and strengthening of water user cooperatives. Based on the final weights, criterias including supportive strategies, education - extension, policy, communications and legal mechanisms, were prioritized, respectively. The results of the sensitivity analysis showed that sub-criterias including reallocation of credit to change the traditional irrigation to drip and sprinkler irrigation, holding extension and educational courses purposed at promoting farmers’knowledge about their responsibilities for the formation and management of water user cooperatives collaborated with the department of Jihad Agricultural Organization (JKO, the department of Cooperatives and Regional Water Organization; credit and investment provision to improve the processing and package industries, modeling appropriate cropping systems based on the area capacity were the most influential sub-criterias in developing and strengthening water user cooperatives.

Electronic Processes at Organic−Organic Interfaces: Insight from Modeling and Implications for Opto-electronic Devices †

KAUST Repository

Beljonne, David

2011-02-08

We report on the recent progress achieved in modeling the electronic processes that take place at interfaces between π-conjugated materials in organic opto-electronic devices. First, we provide a critical overview of the current computational techniques used to assess the morphology of organic: organic heterojunctions; we highlight the compromises that are necessary to handle large systems and multiple time scales while preserving the atomistic details required for subsequent computations of the electronic and optical properties. We then review some recent theoretical advances in describing the ground-state electronic structure at heterojunctions between donor and acceptor materials and highlight the role played by charge-transfer and long-range polarization effects. Finally, we discuss the modeling of the excited-state electronic structure at organic:organic interfaces, which is a key aspect in the understanding of the dynamics of photoinduced electron-transfer processes. © 2010 American Chemical Society.

Efficient Mechanisms of Cooperation between Non-Governmental Organisations and Public Authorities

Directory of Open Access Journals (Sweden)

Rucsandra FILLOREANU

2015-09-01

Full Text Available This paper aims to present to the wide public a success story concerning the efficient cooperation between the civil society as a whole (citizens, NGOs, stake holders and public administration authorities. The success consists in using and strengthening dialogue measures within the collaboration of the two actors. The research is based on a study case. This was run through an EU funded project - “Efficient mechanisms of cooperation with public authorities”. The goal of the project was to increase the capacity of non-governmental organizations to cooperate with the public administration institutions. In order to reach the proposed aim there have been organized a series of theoretical and practical training courses, roundtable discussions and study-visits. Through this manner it has been encouraged and practiced the structured dialog on public agenda issues between the representatives of the local and national authorities and the active citizens. The outputs of the project consist in one Public Consultation Guide elaborated on the basis of good practices acknowledged through the project and two local citizens` initiatives on local public administration matters that have been brought into the public attention of the decision-making actors. Active citizenship, structured dialogue between civil society and state actors, developed tools for effective advocacy and lobby that are part of the success story that we intend to present through this study case.

Japan's prospects in the Shanghai cooperation organization

OpenAIRE

Nurgaliev, Marat

2009-01-01

At the present stage, the Shanghai Cooperation Organization (SCO) is arousing great interest in the international community. The leading actors in international relations, such as the U.S., Japan, and the European countries, are keeping a careful watch over the organization's development. The interest of these countries is mainly related to the lack of information about the SCO's actual activity and the organization's real essence. The leaders of the SCO member states constantly assure everyo...

South-South cooperation as a mechanism to strengthen public ...

African Journals Online (AJOL)

South-South cooperation as a mechanism to strengthen public health services in Africa: ... PROMOTING ACCESS TO AFRICAN RESEARCH ... Implementation of new models of development cooperation have been on the increase ... health system strengthening, aid effectiveness, sustainable development goals, Africa ...

Optoelectronics circuits manual

CERN Document Server

Marston, R M

2013-01-01

Optoelectronics Circuits Manual covers the basic principles and characteristics of the best known types of optoelectronic devices, as well as the practical applications of many of these optoelectronic devices. The book describes LED display circuits and LED dot- and bar-graph circuits and discusses the applications of seven-segment displays, light-sensitive devices, optocouplers, and a variety of brightness control techniques. The text also tackles infrared light-beam alarms and multichannel remote control systems. The book provides practical user information and circuitry and illustrations.

New Development of Membrane Base Optoelectronic Devices

Directory of Open Access Journals (Sweden)

Leon Hamui

2017-12-01

Full Text Available It is known that one factor that affects the operation of optoelectronic devices is the effective protection of the semiconductor materials against environmental conditions. The permeation of atmospheric oxygen and water molecules into the device structure induces degradation of the electrodes and the semiconductor. As a result, in this communication we report the fabrication of semiconductor membranes consisting of Magnesium Phthalocyanine-allene (MgPc-allene particles dispersed in Nylon 11 films. These membranes combine polymer properties with organic semiconductors properties and also provide a barrier effect for the atmospheric gas molecules. They were prepared by high vacuum evaporation and followed by thermal relaxation technique. For the characterization of the obtained membranes, Fourier-transform infrared spectroscopy (FT-IR, scanning electron microscopy (SEM, and energy dispersive spectroscopy (EDS were used to determine the chemical and microstructural properties. UV-ViS, null ellipsometry, and visible photoluminescence (PL at room temperature were used to characterize the optoelectronic properties. These results were compared with those obtained for the organic semiconductors: MgPc-allene thin films. Additionally, semiconductor membranes devices have been prepared, and a study of the device electronic transport properties was conducted by measuring electrical current density-voltage (J-V characteristics by four point probes with different wavelengths. The resistance properties against different environmental molecules are enhanced, maintaining their semiconductor functionality that makes them candidates for optoelectronic applications.

Design and Control of Cooperativity in Spin-Crossover in Metal–Organic Complexes: A Theoretical Overview

Directory of Open Access Journals (Sweden)

Hrishit Banerjee

2017-07-01

Full Text Available Metal organic complexes consisting of transition metal centers linked by organic ligands, may show bistability which enables the system to be observed in two different electronic states depending on external condition. One of the spectacular examples of molecular bistability is the spin-crossover phenomena. Spin-Crossover (SCO describes the phenomena in which the transition metal ion in the complex under the influence of external stimuli may show a crossover between a low-spin and high-spin state. For applications in memory devices, it is desirable to make the SCO phenomena cooperative, which may happen with associated hysteresis effect. In this respect, compounds with extended solid state structures containing metal ions connected by organic spacer linkers like linear polymers, coordination network solids are preferred candidates over isolated molecules or molecular assemblies. The microscopic understanding, design and control of mechanism driving cooperativity, however, are challenging. In this review we discuss the recent theoretical progress in this direction.

Co-operation and Self-Organization

Directory of Open Access Journals (Sweden)

Christian Fuchs

2008-07-01

structures. This today culminates in global problems such as the ecological crisis, high risk technologies, poverty, unemployment, wars, armed conflicts, terrorism, etc. In order to solve these problems our social systems need re-design in terms of ecological sustainability, alliance technology, participatory economy, participatory democracy, and participatory culture. Participation is an integrated notion that is based on co-operation, selfdetermination, and inclusion in multiple dimensions. A system can be considered as participatory if power in the system is distributed in such a way that all members and concerned individuals can own the system co-operatively and can produce, decide and live in the system co-operatively. Participation is frequently understood in the very narrow sense of concerned people taking somehow part in decision processes. Such an understanding is limited to the political dimension and says nothing about the scope and dimension of participation. There are several dimensions of participation in a social system or in society: producing, owning, consuming (economic dimension, deciding, goal-setting, evaluating (political dimension, forming knowledge/norms/values/images/visions, communicating, networking, self-realizing (cultural dimension. Participation in each of these ten dimensions can be low, medium or high/full. The participation matrix describes the degree of participation in an organization/society with the help of the three dimensions of economy, politics and culture and an analysis of the scope of participation (economic, political, cultural.

A proposed new mechanism for research and development co-operation

International Nuclear Information System (INIS)

Dolan, T.

2001-01-01

Scientists in developing countries sometimes lack knowledge of recent developments, co-operation with advanced countries, and government appreciation of the importance and quality of their work. The present IAEA mechanisms like CRPs and TC projects are very helpful but do not fully meet R and D co-operation needs of these scientists. A new complementary mechanism of co-operation among the Member States is proposed that would utilize IAEA services through a suitable agreement. The IAEA could help to evaluate joint R and D proposals, to provide an example legal agreement, to monitor progress, to disseminate the results, and, in some cases, to administer joint funds. This new mechanism would be similar to ITER, but on a smaller scale, and applicable to all fields of nuclear R and D. (author)

An optoelectronic integrated device including a laser and its driving circuit

Energy Technology Data Exchange (ETDEWEB)

Matsueda, H.; Nakano, H.; Tanaka, T.P.

1984-10-01

A monolithic optoelectronic integrated circuit (OEIC) including a laser diode, photomonitor and driving and detecting circuits has been fabricated on a semi-insulating GaAs substrate. The OEIC has a horizontal integrating structure which is suitable for realising high-density multifunctional devices. The fabricating process and the static and dynamic characteristics of the optical and electronic elements are described. The preliminary results of the co-operative operation of the laser and its driving circuit are also presented.

An active cooperation-aware spectrum allocation mechanism for body sensor networks.

Science.gov (United States)

Jiang, Fu; Guo, Ying; Peng, Jun; Hu, Jiankun

2015-01-28

A cognitive radio-based spectrum allocation scheme using an active cooperative-aware mechanism is proposed in this paper. The scheme ensures that the primary user and secondary users cooperate actively for their own benefits. The primary user releases some spectrum resources to secondary users to actively stimulate them to actively join the cooperative transmission of the primary user, and secondary users help the primary user to relay data in return, as well as its self-data transmission at the same time. The Stackelberg game is used to evenly and jointly optimize the utilities of both the primary and secondary users. Simulation results show that the proposed active cooperation-aware mechanism could improve the body sensor network performance.

Cooperation mechanisms of the EU renewable energy directive and flexible mechanisms of the Kyoto Protocol: comparison and lessons learnt. Working paper

Energy Technology Data Exchange (ETDEWEB)

Frieden, Dorian; Tuerk, Andreas; Steiner, Daniel

2013-07-15

This working paper discusses similarities and differences between the cooperation mechanisms of the EU renewable energy directive (RES directive) and the flexible mechanisms of the Kyoto Protocol. The cooperation mechanisms allow the (virtual) trade of renewable energy and were introduced with the RES directive to provide Member States (MS) with greater flexibility to achieve their national targets for renewable energy sources (RES). A similar kind of flexibility is known from the flexible mechanisms of the Kyoto Protocol which aim at the cost efficient achievement of emission reduction targets. Lessons learned from the Kyoto mechanisms may allow conclusions to be drawn on the design and implementation of the renewable energy cooperation mechanisms. This paper first gives an overview of the cooperation mechanisms regarding their potential, advantages and disadvantages, barriers and preconditions. This is followed by a brief explanation of and a systematic comparison with the flexible mechanisms of the Kyoto Protocol – Joint Implementation (JI); Clean Development Mechanism (CDM); and International Emissions Trading (IET). A gamut of factors influenced the success of the Kyoto mechanisms in general and in specific national contexts. Therefore, it is not possible to directly transfer past experiences with the Kyoto mechanisms to the capability of specific nations to make use of the renewable energy cooperation mechanisms. A comparison of specific features, such as the mechanism type (transfer, project-based, support scheme), price building and specific barriers can, however, help anticipate the possible dynamics and challenges of the cooperation mechanisms. Experiences with the Kyoto mechanisms show that predictions based on supply-demand analysis were valid only to a limited extent and that specific factors such as institutional capacity constraints or legal uncertainties delayed or prevented the use of the mechanisms in some cases. Similarly, for the cooperation

Influence of Molecular Conformations and Microstructure on the Optoelectronic Properties of Conjugated Polymers

KAUST Repository

Botiz, Ioan; Stingelin, Natalie

2014-01-01

It is increasingly obvious that the molecular conformations and the long-range arrangement that conjugated polymers can adopt under various experimental conditions in bulk, solutions or thin films, significantly impact their resulting optoelectronic properties. As a consequence, the functionalities and efficiencies of resulting organic devices, such as field-effect transistors, light-emitting diodes, or photovoltaic cells, also dramatically change due to the close structure/property relationship. A range of structure/optoelectronic properties relationships have been investigated over the last few years using various experimental and theoretical methods, and, further, interesting correlations are continuously revealed by the scientific community. In this review, we discuss the latest findings related to the structure/optoelectronic properties interrelationships that exist in organic devices fabricated with conjugated polymers in terms of charge mobility, absorption, photoluminescence, as well as photovoltaic properties. © 2014 by the authors.

Influence of Molecular Conformations and Microstructure on the Optoelectronic Properties of Conjugated Polymers

Directory of Open Access Journals (Sweden)

Ioan Botiz

2014-03-01

Full Text Available It is increasingly obvious that the molecular conformations and the long-range arrangement that conjugated polymers can adopt under various experimental conditions in bulk, solutions or thin films, significantly impact their resulting optoelectronic properties. As a consequence, the functionalities and efficiencies of resulting organic devices, such as field-effect transistors, light-emitting diodes, or photovoltaic cells, also dramatically change due to the close structure/property relationship. A range of structure/optoelectronic properties relationships have been investigated over the last few years using various experimental and theoretical methods, and, further, interesting correlations are continuously revealed by the scientific community. In this review, we discuss the latest findings related to the structure/optoelectronic properties interrelationships that exist in organic devices fabricated with conjugated polymers in terms of charge mobility, absorption, photoluminescence, as well as photovoltaic properties.

Influence of Molecular Conformations and Microstructure on the Optoelectronic Properties of Conjugated Polymers

KAUST Repository

Botiz, Ioan

2014-03-19

It is increasingly obvious that the molecular conformations and the long-range arrangement that conjugated polymers can adopt under various experimental conditions in bulk, solutions or thin films, significantly impact their resulting optoelectronic properties. As a consequence, the functionalities and efficiencies of resulting organic devices, such as field-effect transistors, light-emitting diodes, or photovoltaic cells, also dramatically change due to the close structure/property relationship. A range of structure/optoelectronic properties relationships have been investigated over the last few years using various experimental and theoretical methods, and, further, interesting correlations are continuously revealed by the scientific community. In this review, we discuss the latest findings related to the structure/optoelectronic properties interrelationships that exist in organic devices fabricated with conjugated polymers in terms of charge mobility, absorption, photoluminescence, as well as photovoltaic properties. © 2014 by the authors.

Opto-electronic devices from block copolymers and their oligomers.

NARCIS (Netherlands)

Hadziioannou, G

1997-01-01

This paper presents research activities towards the development of polymer materials and devices for optoelectronics, An approach to controlling the conjugation length and transferring the luminescence properties of organic molecules to polymers through black copolymers containing well-defined

An Active Cooperation-Aware Spectrum Allocation Mechanism for Body Sensor Networks

Directory of Open Access Journals (Sweden)

Fu Jiang

2015-01-01

Full Text Available A cognitive radio-based spectrum allocation scheme using an active cooperative-aware mechanism is proposed in this paper. The scheme ensures that the primary user and secondary users cooperate actively for their own benefits. The primary user releases some spectrum resources to secondary users to actively stimulate them to actively join the cooperative transmission of the primary user, and secondary users help the primary user to relay data in return, as well as its self-data transmission at the same time. The Stackelberg game is used to evenly and jointly optimize the utilities of both the primary and secondary users. Simulation results show that the proposed active cooperation-aware mechanism could improve the body sensor network performance.

Lessons from a cooperative, bacterial-animal association: the Vibrio fischeri-Euprymna scolopes light organ symbiosis.

Science.gov (United States)

Ruby, E G

1996-01-01

Although the study of microbe-host interactions has been traditionally dominated by an interest in pathogenic associations, there is an increasing awareness of the importance of cooperative symbiotic interactions in the biology of many bacteria and their animal and plant hosts. This review examines a model system for the study of such symbioses, the light organ association between the bobtail squid Euprymna scolopes and the marine luminous bacterium Vibrio fischeri. Specifically, the initiation, establishment, and persistence of the benign bacterial infection of the juvenile host light organ are described, as are efforts to understand the mechanisms underlying this specific colonization program. Using molecular genetic techniques, mutant strains of V. fischeri have been constructed that are defective at specific stages of the development of the association. Some of the lessons that these mutants have begun to teach us about the complex and long-term nature of this cooperative venture are summarized.

Telemedicine optoelectronic biomedical data processing system

Science.gov (United States)

Prosolovska, Vita V.

2010-08-01

The telemedicine optoelectronic biomedical data processing system is created to share medical information for the control of health rights and timely and rapid response to crisis. The system includes the main blocks: bioprocessor, analog-digital converter biomedical images, optoelectronic module for image processing, optoelectronic module for parallel recording and storage of biomedical imaging and matrix screen display of biomedical images. Rated temporal characteristics of the blocks defined by a particular triggering optoelectronic couple in analog-digital converters and time imaging for matrix screen. The element base for hardware implementation of the developed matrix screen is integrated optoelectronic couples produced by selective epitaxy.

Cooperative catalysis by silica-supported organic functional groups

OpenAIRE

Margelefsky, Eric L.; Zeidan, Ryan K.; Davis, Mark E.

2008-01-01

Hybrid inorganic–organic materials comprising organic functional groups tethered from silica surfaces are versatile, heterogeneous catalysts. Recent advances have led to the preparation of silica materials containing multiple, different functional groups that can show cooperative catalysis; that is, these functional groups can act together to provide catalytic activity and selectivity superior to what can be obtained from either monofunctional materials or homogeneous catalysts. This tutorial...

Interface Engineering and Morphology Study of Thin Film Organic-Inorganic Halide Perovskite Optoelectronic Devices

Science.gov (United States)

Meng, Lei

significantly improved compared with cells made with organic layers. Degradation mechanisms were investigated and important guidelines were derived for future device design with a view to achieving both highly efficient and stable solar devices. Organometal halide based perovskite material has great optoelectronic proprieties, for example, shallow traps, benign grain boundaries and high diffusion length. The perovskite LEDs show pure electroluminescence (EL) with narrow full width at half maximum (FWHM), which is an advantage for display, lighting or lasing applications. In chapter five, perovskite LEDs are demonstrated employing solution processed charge injection layers with a quantum efficiency of 1.16% with a very low driving voltage.

The Self-Organized Archive: SPASE, PDS and Archive Cooperatives

Science.gov (United States)

King, T. A.; Hughes, J. S.; Roberts, D. A.; Walker, R. J.; Joy, S. P.

2005-05-01

Information systems with high quality metadata enable uses and services which often go beyond the original purpose. There are two types of metadata: annotations which are items that comment on or describe the content of a resource and identification attributes which describe the external properties of the resource itself. For example, annotations may indicate which columns are present in a table of data, whereas an identification attribute would indicate source of the table, such as the observatory, instrument, organization, and data type. When the identification attributes are collected and used as the basis of a search engine, a user can constrain on an attribute, the archive can then self-organize around the constraint, presenting the user with a particular view of the archive. In an archive cooperative where each participating data system or archive may have its own metadata standards, providing a multi-system search engine requires that individual archive metadata be mapped to a broad based standard. To explore how cooperative archives can form a larger self-organized archive we will show how the Space Physics Archive Search and Extract (SPASE) data model will allow different systems to create a cooperative and will use Planetary Data System (PDS) plus existing space physics activities as a demonstration.

Organic 'Plastic' Optoelectronic Devices

International Nuclear Information System (INIS)

Sariciftci, N.S.

2006-01-01

Recent developments on conjugated polymer based photovoltaic diodes and photoactive organic field effect transistors (photOFETs) are discussed. The photophysics of such devices is based on the photoinduced charge transfer from donor type semiconducting conjugated polymers onto acceptor type conjugated polymers or acceptor molecules such as Buckminsterfullerene, C 6 0. Potentially interesting applications include sensitization of the photoconductivity and photovoltaic phenomena as well as photoresponsive organic field effect transistors (photOFETs). Furthermore, organic polymeric/inorganic nanoparticle based 'hybrid' solar cells will be discussed. This talk gives an overview of materials' aspect, charge-transport, and device physics of organic diodes and field-effect transistors. Furthermore, due to the compatibility of carbon/hydrogen based organic semiconductors with organic biomolecules and living cells there can be a great opportunity to integrate such organic semiconductor devices (biOFETs) with the living organisms. In general the largely independent bio/lifesciences and information technology of today, can be thus bridged in an advanced cybernetic approach using organic semiconductor devices embedded in bio-lifesciences. This field of bio-organic electronic devices is proposed to be an important mission of organic semiconductor devices

Design options for cooperation mechanisms under the new European renewable energy directive

International Nuclear Information System (INIS)

Klessmann, Corinna; Lamers, Patrick; Ragwitz, Mario; Resch, Gustav

2010-01-01

In June 2009, a new EU directive on the promotion of renewable energy sources (RES) entered into effect. The directive 2009/28/EC, provides for three cooperation mechanisms that will allow member states to achieve their national RES target in cooperation with other member states: statistical transfer, joint projects, and joint support schemes. This article analyses the pros and cons of the three mechanisms and explores design options for their implementation through strategic and economic questions: How to counterbalance the major drawbacks of each mechanism? How to reflect a balance of costs and benefits between the involved member states? The analysis identifies a number of design options that respond to these questions, e.g. long term contracts to ensure sufficient flexibility for statistical transfers, a coordinated, standardised joint project approach to increase transparency in the European market, and a stepwise harmonisation of joint support schemes that is based on a cost-effective accounting approach. One conclusion is that the three cooperation mechanisms are closely interlinked. One can consider their relation to be a gradual transition from member state cooperation under fully closed national support systems in case of statistical transfers, to cooperation under fully open national support systems in a joint support scheme.

Conditional dissociation as a punishment mechanism in the evolution of cooperation

Science.gov (United States)

Qu, Xinglong; Zhou, Changli; Cao, Zhigang; Yang, Xiaoguang

2016-05-01

Recent studies show that conditional dissociation, a.k.a. post-interaction partner-refusal, can promote the emergence and stability of cooperation. However, in most of these studies, players' strategies are restricted to pure ones, which is obviously inconsistent with many biological and economic situations. Another concern with line of these studies is that conditional dissociation is often combined with other mechanisms. These mechanisms may favor cooperation per se, leaving it unclear whether conditional dissociation is indeed a key factor. In this paper, we study a clean model, pruning all the factors other than conditional dissociation that may favor cooperation. We find that conditional dissociation, which could be viewed as a variant of peer punishment, does promote cooperation, no matter whether mixed strategies are allowed or not. This confirms the previous findings in the literature. In addition, compared with the pure strategy scenario, cooperators are less competitive when mixed strategies are allowed. Our main finding is supported by both the numerical simulations and the theoretical analysis of Neutrally Stable Strategy. We also find that cooperative behavior is favored when waiting time and/or the population's lifespan are longer.

Optoelectronic Devices Advanced Simulation and Analysis

CERN Document Server

Piprek, Joachim

2005-01-01

Optoelectronic devices transform electrical signals into optical signals and vice versa by utilizing the sophisticated interaction of electrons and light within micro- and nano-scale semiconductor structures. Advanced software tools for design and analysis of such devices have been developed in recent years. However, the large variety of materials, devices, physical mechanisms, and modeling approaches often makes it difficult to select appropriate theoretical models or software packages. This book presents a review of devices and advanced simulation approaches written by leading researchers and software developers. It is intended for scientists and device engineers in optoelectronics, who are interested in using advanced software tools. Each chapter includes the theoretical background as well as practical simulation results that help to better understand internal device physics. The software packages used in the book are available to the public, on a commercial or noncommercial basis, so that the interested r...

A Cross-Layer Cooperation Mechanism of Wireless Networks Based on Game Theory

OpenAIRE

Chunsheng, Cui; Yongjian, Yang; Liping, Huang

2014-01-01

To meet the wireless network congestion control problem, we give a definition of congestion degree classification and propose a mechanism of directed cooperative path net, guided by the wireless network’s cross-layer design methods and node cooperation principles. Considering the virtual collision and “starved” phenomenon in congested networks, the QRD mechanism and channel competition mechanism QPCG are proposed, with introducing the game theory into the cross-layer design. Simulation result...

78 FR 42084 - Cooperative Agreement to Support the World Trade Organization's Standards and Trade Development...

Science.gov (United States)

2013-07-15

...] Cooperative Agreement to Support the World Trade Organization's Standards and Trade Development Facility... The STDF is a unique global partnership established by the Food and Agriculture Organization, World... cooperative agreement in fiscal year 2013 (FY 2013) to the World Trade Organization's (WTO) Standards and...

Tuning the optoelectronic properties of amorphous MoOx films by reactive sputtering

DEFF Research Database (Denmark)

Fernandes Cauduro, André Luis; Fabrim, Zacarias Eduardo; Ahmadpour, Mehrad

2015-01-01

In this letter, we report on the effect of oxygen partial pressure and sputtering power on amorphous DC-sputtered MoOx films. We observe abrupt changes in the optoelectronic properties of the reported films by increasing the oxygen partial pressure from 1.00 ? 10?3 mbar to 1.37 ? 10?3 mbar during...... significantly the microstructure of the studied films. The presence of states within the band gap due to the lack of oxygen is the most probable mechanism for generat- ing a change in electrical conductivity as well as optical absorption in DC-sputtered MoOx. The large tuning range of the optoelectronic...... properties in these films holds strong promise for their implementation in optoelectronic devices....

Two-Dimensional CH₃NH₃PbI₃ Perovskite: Synthesis and Optoelectronic Application.

Science.gov (United States)

Liu, Jingying; Xue, Yunzhou; Wang, Ziyu; Xu, Zai-Quan; Zheng, Changxi; Weber, Bent; Song, Jingchao; Wang, Yusheng; Lu, Yuerui; Zhang, Yupeng; Bao, Qiaoliang

2016-03-22

Hybrid organic-inorganic perovskite materials have received substantial research attention due to their impressively high performance in photovoltaic devices. As one of the oldest functional materials, it is intriguing to explore the optoelectronic properties in perovskite after reducing it into a few atomic layers in which two-dimensional (2D) confinement may get involved. In this work, we report a combined solution process and vapor-phase conversion method to synthesize 2D hybrid organic-inorganic perovskite (i.e., CH3NH3PbI3) nanocrystals as thin as a single unit cell (∼1.3 nm). High-quality 2D perovskite crystals have triangle and hexagonal shapes, exhibiting tunable photoluminescence while the thickness or composition is changed. Due to the high quantum efficiency and excellent photoelectric properties in 2D perovskites, a high-performance photodetector was demonstrated, in which the current can be enhanced significantly by shining 405 and 532 nm lasers, showing photoresponsivities of 22 and 12 AW(-1) with a voltage bias of 1 V, respectively. The excellent optoelectronic properties make 2D perovskites building blocks to construct 2D heterostructures for wider optoelectronic applications.

Study on Cooperative Mechanism of Prefabricated Producers Based on Evolutionary Game Theory

Directory of Open Access Journals (Sweden)

Tongyao Feng

2017-01-01

Full Text Available Good cooperation mechanism is an important guarantee for the advancement of industrialization construction. To strengthen the partnership between producers, we analyze the behavior evolution trend of both parties using an evolutionary game theory. Based on the original model, the mechanism of coordination and cooperation between prefabricated producers is explained under the condition of punishment and incentive. The results indicate that stable evolutionary strategies exist under both cooperation and noncooperation, and the evolutionary results are influenced by the initial proportion of both decision-making processes. The government can support the production enterprises to establish a solid partnership through effective punishment and incentive mechanisms to reduce the initial cost in the supply chain of prefabricated construction, resulting in a win-win situation.

Crystalline Molybdenum Oxide Thin-Films for Application as Interfacial Layers in Optoelectronic Devices

DEFF Research Database (Denmark)

Fernandes Cauduro, André Luis; dos Reis, Roberto; Chen, Gong

2017-01-01

The ability to control the interfacial properties in metal-oxide thin films through surface defect engineering is vital to fine-tune their optoelectronic properties and thus their integration in novel optoelectronic devices. This is exemplified in photovoltaic devices based on organic, inorganic...... or hybrid technologies, where precise control of the charge transport properties through the interfacial layer is highly important for improving device performance. In this work, we study the effects of in situ annealing in nearly stoichiometric MoOx (x ∼ 3.0) thin-films deposited by reactive sputtering. We...... with structural characterizations, this work addresses a novel method for tuning, and correlating, the optoelectronic properties and microstructure of device-relevant MoOx layers....

Functional Patterns in International Organizations for University Cooperation in Latin America and the Caribbean

Science.gov (United States)

Lopez, Daniel A.; Lopez, Daniel C.; Andrade, Lorenzo I.; Lopez, Boris A.

2011-01-01

This study analyzes the coverage, organizational patterns, problems and trends of international organizations for university cooperation in Latin America and the Caribbean. More than 30 international organizations for cooperation currently operating in Latin America and the Caribbean were identified. Two groups of institutions with more than 60%…

78 FR 49756 - Notification of a Cooperative Agreement Award to the World Health Organization

Science.gov (United States)

2013-08-15

...: Notification of a sole source Cooperative Agreement Award to the World Health Organization for a grant titled... World Health Organization (WHO) as soon as possible, and any confirmed smallpox case would generate an... DEPARTMENT OF HEALTH AND HUMAN SERVICES Notification of a Cooperative Agreement Award to the World...

Semiconductor opto-electronics

CERN Document Server

Moss, TS; Ellis, B

1972-01-01

Semiconductor Opto-Electronics focuses on opto-electronics, covering the basic physical phenomena and device behavior that arise from the interaction between electromagnetic radiation and electrons in a solid. The first nine chapters of this book are devoted to theoretical topics, discussing the interaction of electromagnetic waves with solids, dispersion theory and absorption processes, magneto-optical effects, and non-linear phenomena. Theories of photo-effects and photo-detectors are treated in detail, including the theories of radiation generation and the behavior of semiconductor lasers a

Electron beam and mechanical lithographies as enabling factors for organic-based device fabrication

International Nuclear Information System (INIS)

Visconti, P.; Pisignano, D.; Della Torre, A.; Persano, L.; Maruccio, G.; Biasco, A.; Cingolani, R.; Rinaldi, R.

2005-01-01

Organic-based photonics and molecular electronics are attracting an increasing interest in modern science. The realization of high-resolution master structures by electron beam lithography (EBL) and their transfer to different organic functional materials by mechanical lithographies allow to fully exploit the wide flexibility of molecular systems for opto- and nanoelectronic devices. Planar nanojunctions, consisting of two metallic electrodes separated by an insulating medium, permit to test the molecular conduction properties. Since the typical size of a biomolecule is of the order of a few nanometer, hybrid molecular electronic (HME) devices need metallic electrodes separated by a nanometer-scale channel. Conversely, photonic applications often require 100 nm to 1 μm features on large areas. In this work, we report on the fabrication of both large-area periodic master structures with resolution down to 200 nm, and planar metallic electrodes with sub-10 nm separation obtained by EBL followed by metal electroplating deposition. The fabricated 3-terminal bio-nanodevices show a transistor-like behaviour with a maximum voltage gain of 0.76. Moreover, we developed a number of mechanical patterning methods, including soft hot embossing, rapid prototyping, sub-micrometer fluidics, high- and room-temperature nanoimprinting, to fabricate planar nanostructures on both biomolecular and organic materials. These allowed us a high-fidelity pattern transfer up to 100-nm scale resolution, without reducing the emission yields of light-emitting organics, thus opening the way to the one-step realization of organic-based confined optoelectronic devices

Case Writing Projects in Co-Operation with Companies and Organizations

OpenAIRE

Bengtsson, Lars; Asplund, Carl-Johan

2008-01-01

The purpose of this paper is to present the process and evaluation of case writing projects in co-operation with companies and organizations in a course for engineering students. The case writing projects could provide an illustration and example framework for working with companies in constructing cases. Normally cases are constructed for teaching purposes in higher education. However, in order to get closer co-operation and more interest from the companies the authors encouraged the student...

Exfoliating and Dispersing Few-Layered Graphene in Low-Boiling-Point Organic Solvents towards Solution-Processed Optoelectronic Device Applications.

Science.gov (United States)

Zhang, Lu; Miao, Zhongshuo; Hao, Zhen; Liu, Jun

2016-05-06

With normal organic surfactants, graphene can only be dispersed in water and cannot be dispersed in low-boiling-point organic solvents, which hampers its application in solution-processed organic optoelectronic devices. Herein, we report the exfoliation of graphite into graphene in low-boiling-point organic solvents, for example, methanol and acetone, by using edge-carboxylated graphene quantum dots (ECGQD) as the surfactant. The great capability of ECGQD for graphene dispersion is due to its ultralarge π-conjugated unit that allows tight adhesion on the graphene surface through strong π-π interactions, its edge-carboxylated structure that diminishes the steric effects of the oxygen-containing functional groups on the basal plane of ECGQD, and its abundance of carboxylic acid groups for solubility. The graphene dispersion in methanol enables the application of graphene:ECGQD as a cathode interlayer in polymer solar cells (PSCs). Moreover, the PSC device performance of graphene:ECGQD is better than that of Ca, the state-of-the-art cathode interlayer material. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Cellulose Nanofibers for Optoelectronic Conversion and Energy Storage

Directory of Open Access Journals (Sweden)

Yongfeng Luo

2014-01-01

Full Text Available Cellulose widely exists in plant tissues. Due to the large pores between the cellulose units, the regular paper is nontransparent that cannot be used in the optoelectronic devices. But some chemical and physical methods such as 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO oxidation can be used to improve the pores scale between the cellulose units to reach nanometer level. The cellulose nanofibers (CNFs have good mechanical strength, flexibility, thermostability, and low thermal expansion. The paper made of these nanofibers represent a kind of novel nanostructured material with ultrahigh transparency, ultrahigh haze, conductivity, biodegradable, reproducible, low pollution, environment friendly and so on. These advantages make the novel nanostructured paper apply in the optoelectronic device possible, such as electronics energy storage devices. This kind of paper is considered most likely to replace traditional materials like plastics and glass, which is attracting widespread attention, and the related research has also been reported. The purpose of this paper is to review CNFs which are applied in optoelectronic conversion and energy storage.

Cooperation Mechanisms To Achieve Eu Renewable Targets

DEFF Research Database (Denmark)

Klinge Jacobsen, Henrik; Pade, Lise-Lotte; Schröder, Sascha Thorsten

2014-01-01

targets. Furthermore, countries might find themselves competing for investment in a market with limited capital available. In both cases, the cost-efficiency of the renewable support policies is reduced compared to a coordinated solution. Barriers for joint support such as network regulation regarding......There are considerable benefits from cooperating among member states on meeting the 2020 renewable energy sources (RES) targets. Today countries are supporting investments in renewable energy by many different types of support schemes and with different levels of support. The EU has opened...... for cooperation mechanisms such as joint support schemes for promoting renewable energy to meet the 2020 targets. The potential coordination benefits, with more efficient localisation and composition of renewable investment, can be achieved by creating new areas/sub-segments of renewable technologies where...

Investigation, study and practice of optoelectronic MOOCs

Science.gov (United States)

Shi, Jianhua; Liu, Wei; Lei, Bing; Yao, Tianfu; Fu, Sihua

2017-08-01

MOOC(Massive Open Online Course) is a new teaching model that has been springing up since 2012. The typical characters are short teaching video, massive learners, flexible place and time to study, etc. Although MOOC is very popular now, opto-electronic MOOCs are not much enough to meet the need of online learners. In this paper, the phylogeny, the current situation and the characters of MOOC were described, the most famous MOOCs' websites, such as Udacity, Coursera, edX, Chinese College MOOC, xuetangx, were introduced, the opto-electronic MOOCs come from these famous MOOCs' website were investigated extensively and studied deeply, the "Application of Opto-electronic Technology MOOC" which was established by our group is introduced, and some conclusions are obtained. These conclusions can give some suggestions to the online learners who are interested in opto-electronic and the teachers who are teaching the opto-electronic curriculums. The preparation of "Opto-electronic Technology MOOC" is described in short.

Optoelectronic properties of a novel fluorene derivative for organic light-emitting diode

Energy Technology Data Exchange (ETDEWEB)

Yu, Junsheng; Lou, Shuangling; Qian, Jincheng; Jiang, Yadong [University of Electronic Science and Technology of China (UESTC), State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, Chengdu (China); Zhang, Qing [Shanghai Jiaotong University, Department of Polymer Science, School of Chemistry and Chemical Technology, Shanghai (China)

2009-03-15

We report the optoelectronic properties of a novel fluorene derivative of 6,6'-(9H-fluoren-9,9-diyl)bis(2,3-bis (9,9-dihexyl-9H-fluoren-2-yl)quinoxaline) (BFLBBFLYQ) used for organic light-emitting diode. UV-Vis absorption, photoluminescence (PL) and electroluminescence (EL) spectra of BFLBBFLYQ and the blend doped with N,N'-biphenyl-N,N'-bis-(3-methylphenyl)-1,1'-biphenyl-4,4'-di- amine (TPD) in solid state and in solution were investigated. The results showed that BFLBBFLYQ had a PL peak at 451 nm in solid and solution states and an EL peak at 483 nm with a broad emission band, resulting from fluorenone defects. Exciplex emission was observed in BFLBBFLYQ-TPD blend solid state with a green emission peaking at 530 nm. Also the blend in solution showed solvatochromism in polarity solvent upon UV irradiation. A new absorption band appeared at around 470 nm of BFLBBFLYQ-TPD blend in chloroform solution, and disappeared when diluted in absorption spectrum. Meanwhile, a low energy emission band from 530 to 580 nm appeared and increased with material concentration and UV irradiation time. (orig.)

Responsibility, administration and social balance in the cooperative companies

Directory of Open Access Journals (Sweden)

Juan Luis Alfonso Alemán

2013-12-01

Full Text Available The Declaration of Values and Cooperative Principles approved in the General Assembly of the International Cooperative Alliance (ACI, taken place in Manchester in 1995 he responds to the demands that it demands the modern cooperative, amid an environment that he/she forces to the consolidation of their cooperative identity. In this declaration the seven principles that govern the operation of all the organizations that you/they conform the cooperative, included movement the Cuban Agricultural Cooperatives settle down, however it is valid to clarify that in the Cuban case our Legislation outlines eleven principles that in a way or another coincides in its content with the seven settled down by the ACI. The execution of these principles demands from the cooperatives an instrument or evaluation mechanism that it considers so much its economic aspects as social. In their great one our majority organizations has instruments of economic administration that are shared by other managerial forms in many cases and they don't respond neither they contribute to the establishment of the cooperative ideal, to the consolidation of its true identity. It is for it that the cooperatives, in spite of its already grateful history and existence, they lack specifically in many places of mechanisms and administration methodologies cooperative.

Benefits and organization of cooperative research for fisheries management

NARCIS (Netherlands)

Johnson, T.R.; Densen, van W.L.T.

2007-01-01

Drawing on research in the northeastern USA and northwestern Europe, a description is given of how cooperative research is organized and a statement made of how involving fishers in research can contribute to better fisheries management. The focus is on improving stock assessments through the

Comprehensive study of the influence of different environments on degradation processes in F8BT: Correlating optoelectronic properties with Raman measurements

International Nuclear Information System (INIS)

Linde, Sivan; Shikler, Rafi

2013-01-01

There is a growing interest in conjugated polymers from both industrial and academic points of views. The reasons are their tunable optoelectronic properties, ease of production, and excellent mechanical properties. However, the ease with which their optoelectronic properties are tunable make devices based on them prone to fast degradation and therefore, short life time. The issue of degradation of organic based optoelectronic devices is the topic of many ongoing researches. However, much less attention is given to degradation processes of the individual components of the devices and their dependence on the environmental conditions. In this work, we report on the degradation of a film of a polyfluorene block copolymer F8BT that is used in a variety of optoelectronic devices under different environments: Sun exposure, heating, and UV exposure in inert and ambient conditions. Degradation was observed in most of the optoelectronic properties of the film. Topographic measurements did not show observable changes of the film morphology following degradation. However, Raman spectroscopy measurements show changes that indicate degradation in one of the building blocks of the copolymer that is associated with electron's conduction. The absolute value of the correlation coefficient between the decrease in the Raman signal and the decrease in the optoelectronic properties is larger than 0.95 under sun exposure it is larger than 0.8 under all other ambient exposures and smaller than 0.65 under inert conditions. These results support the assumption that Oxygen, not necessarily through photo-oxidation, and also water play an important role in the degradation process and indicate the part of the polymer that is most susceptible to degradation

A business process model as a starting point for tight cooperation among organizations

Directory of Open Access Journals (Sweden)

O. Mysliveček

2006-01-01

Full Text Available Outsourcing and other kinds of tight cooperation among organizations are more and more necessary for success on all markets (markets of high technology products are particularly influenced. Thus it is important for companies to be able to effectively set up all kinds of cooperation. A business process model (BPM is a suitable starting point for this future cooperation. In this paper the process of setting up such cooperation is outlined, as well as why it is important for business success. 

Deformable paper origami optoelectronic devices

KAUST Repository

He, Jr-Hau

2017-01-19

Deformable optoelectronic devices are provided, including photodetectors, photodiodes, and photovoltaic cells. The devices can be made on a variety of paper substrates, and can include a plurality of fold segments in the paper substrate creating a deformable pattern. Thin electrode layers and semiconductor nanowire layers can be attached to the substrate, creating the optoelectronic device. The devices can be highly deformable, e.g. capable of undergoing strains of 500% or more, bending angles of 25° or more, and/or twist angles of 270° or more. Methods of making the deformable optoelectronic devices and methods of using, e.g. as a photodetector, are also provided.

Hydrogen-Bonded Organic Semiconductor Micro- And Nanocrystals: From Colloidal Syntheses to (Opto-)Electronic Devices

Science.gov (United States)

2014-01-01

Organic pigments such as indigos, quinacridones, and phthalocyanines are widely produced industrially as colorants for everyday products as various as cosmetics and printing inks. Herein we introduce a general procedure to transform commercially available insoluble microcrystalline pigment powders into colloidal solutions of variously sized and shaped semiconductor micro- and nanocrystals. The synthesis is based on the transformation of the pigments into soluble dyes by introducing transient protecting groups on the secondary amine moieties, followed by controlled deprotection in solution. Three deprotection methods are demonstrated: thermal cleavage, acid-catalyzed deprotection, and amine-induced deprotection. During these processes, ligands are introduced to afford colloidal stability and to provide dedicated surface functionality and for size and shape control. The resulting micro- and nanocrystals exhibit a wide range of optical absorption and photoluminescence over spectral regions from the visible to the near-infrared. Due to excellent colloidal solubility offered by the ligands, the achieved organic nanocrystals are suitable for solution processing of (opto)electronic devices. As examples, phthalocyanine nanowire transistors as well as quinacridone nanocrystal photodetectors, with photoresponsivity values by far outperforming those of vacuum deposited reference samples, are demonstrated. The high responsivity is enabled by photoinduced charge transfer between the nanocrystals and the directly attached electron-accepting vitamin B2 ligands. The semiconducting nanocrystals described here offer a cheap, nontoxic, and environmentally friendly alternative to inorganic nanocrystals as well as a new paradigm for obtaining organic semiconductor materials from commercial colorants. PMID:25253644

Cooperation prevails when individuals adjust their social ties.

Directory of Open Access Journals (Sweden)

Francisco C Santos

2006-10-01

Full Text Available Conventional evolutionary game theory predicts that natural selection favours the selfish and strong even though cooperative interactions thrive at all levels of organization in living systems. Recent investigations demonstrated that a limiting factor for the evolution of cooperative interactions is the way in which they are organized, cooperators becoming evolutionarily competitive whenever individuals are constrained to interact with few others along the edges of networks with low average connectivity. Despite this insight, the conundrum of cooperation remains since recent empirical data shows that real networks exhibit typically high average connectivity and associated single-to-broad-scale heterogeneity. Here, a computational model is constructed in which individuals are able to self-organize both their strategy and their social ties throughout evolution, based exclusively on their self-interest. We show that the entangled evolution of individual strategy and network structure constitutes a key mechanism for the sustainability of cooperation in social networks. For a given average connectivity of the population, there is a critical value for the ratio W between the time scales associated with the evolution of strategy and of structure above which cooperators wipe out defectors. Moreover, the emerging social networks exhibit an overall heterogeneity that accounts very well for the diversity of patterns recently found in acquired data on social networks. Finally, heterogeneity is found to become maximal when W reaches its critical value. These results show that simple topological dynamics reflecting the individual capacity for self-organization of social ties can produce realistic networks of high average connectivity with associated single-to-broad-scale heterogeneity. On the other hand, they show that cooperation cannot evolve as a result of "social viscosity" alone in heterogeneous networks with high average connectivity, requiring the

Understanding the Slow Transient Optoelectronic Response of Hybrid Organic-Inorganic Halide Perovskites

Science.gov (United States)

Jacobs, Daniel Louis

Hybrid organic-inorganic halide perovskites, particularly methylammonium lead triiodide (MAPbI3), have emerged within the past decade as an exciting class of photovoltaic materials. In less than ten years, MAPbI3-based photovoltaic devices have seen unprecedented performance growth, with photoconversion efficiency increasing from 3% to over 22%, making it competitive with traditional high-efficiency solar cells. Furthermore, the fabrication of MAPbI3 devices utilize low-temperature solution processing, which could facilitate ultra low cost manufacturing. However, MAPbI3 suffers from significant instabilities under working conditions that have limited their applications outside of the laboratory. The instability of the MAPbI3 material can be generalized as a complex, slow transient optoelectronic response (STOR). The mechanism of the generalized STOR is dependent on the native defects of MAPbI3, but detailed understanding of the material defect properties is complicated by the complex ionic bonding of MAPbI3. Furthermore, characterization of the intrinsic material's response is complicated by the diverse approach to material processing and device architecture across laboratories around the world. In order to understand and mitigate the significant problems of MAPbI3 devices, a new approach focused on the material response, rather than the full device response, must be pursued. This dissertation highlights the work to analyze and mitigate the STOR intrinsic to MAPbI3. An experimental platform was developed based on lateral interdigitated electrode (IDE) arrays capable of monitoring the current and photoluminescence response simultaneously. By correlating the dynamics of the current and photoluminescence (PL) responses, both charge trapping and ion migration mechanisms were identified to contribute to the STOR. Next, a novel fabrication technique is introduced that is capable of reliably depositing MAPbI3 thin films with grain sizes at least an order of magnitude

Terahertz optoelectronics with surface plasmon polariton diode.

Science.gov (United States)

Vinnakota, Raj K; Genov, Dentcho A

2014-05-09

The field of plasmonics has experience a renaissance in recent years by providing a large variety of new physical effects and applications. Surface plasmon polaritons, i.e. the collective electron oscillations at the interface of a metal/semiconductor and a dielectric, may bridge the gap between electronic and photonic devices, provided a fast switching mechanism is identified. Here, we demonstrate a surface plasmon-polariton diode (SPPD) an optoelectronic switch that can operate at exceedingly large signal modulation rates. The SPPD uses heavily doped p-n junction where surface plasmon polaritons propagate at the interface between n and p-type GaAs and can be switched by an external voltage. The devices can operate at transmission modulation higher than 98% and depending on the doping and applied voltage can achieve switching rates of up to 1 THz. The proposed switch is compatible with the current semiconductor fabrication techniques and could lead to nanoscale semiconductor-based optoelectronics.

Modeling cooperating micro-organisms in antibiotic environment.

Science.gov (United States)

Book, Gilad; Ingham, Colin; Ariel, Gil

2017-01-01

Recent experiments with the bacteria Paenibacillus vortex reveal a remarkable strategy enabling it to cope with antibiotics by cooperating with a different bacterium-Escherichia coli. While P. vortex is a highly effective swarmer, it is sensitive to the antibiotic ampicillin. On the other hand, E. coli can degrade ampicillin but is non-motile when grown on high agar percentages. The two bacterial species form a shared colony in which E. coli is transported by P. vortex and E. coli detoxifies the ampicillin. The paper presents a simplified model, consisting of coupled reaction-diffusion equations, describing the development of ring patterns in the shared colony. Our results demonstrate some of the possible cooperative movement strategies bacteria utilize in order to survive harsh conditions. In addition, we explore the behavior of mixed colonies under new conditions such as antibiotic gradients, synchronization between colonies and possible dynamics of a 3-species system including P. vortex, E. coli and a carbon producing algae that provides nutrients under illuminated, nutrient poor conditions. The derived model was able to simulate an asymmetric relationship between two or three micro-organisms where cooperation is required for survival. Computationally, in order to avoid numerical artifacts due to symmetries within the discretizing grid, the model was solved using a second order Vectorizable Random Lattices method, which is developed as a finite volume scheme on a random grid.

Modeling cooperating micro-organisms in antibiotic environment.

Directory of Open Access Journals (Sweden)

Gilad Book

Full Text Available Recent experiments with the bacteria Paenibacillus vortex reveal a remarkable strategy enabling it to cope with antibiotics by cooperating with a different bacterium-Escherichia coli. While P. vortex is a highly effective swarmer, it is sensitive to the antibiotic ampicillin. On the other hand, E. coli can degrade ampicillin but is non-motile when grown on high agar percentages. The two bacterial species form a shared colony in which E. coli is transported by P. vortex and E. coli detoxifies the ampicillin. The paper presents a simplified model, consisting of coupled reaction-diffusion equations, describing the development of ring patterns in the shared colony. Our results demonstrate some of the possible cooperative movement strategies bacteria utilize in order to survive harsh conditions. In addition, we explore the behavior of mixed colonies under new conditions such as antibiotic gradients, synchronization between colonies and possible dynamics of a 3-species system including P. vortex, E. coli and a carbon producing algae that provides nutrients under illuminated, nutrient poor conditions. The derived model was able to simulate an asymmetric relationship between two or three micro-organisms where cooperation is required for survival. Computationally, in order to avoid numerical artifacts due to symmetries within the discretizing grid, the model was solved using a second order Vectorizable Random Lattices method, which is developed as a finite volume scheme on a random grid.

EPA's Role with the Organization for Economic Cooperation and Development (OECD)

Science.gov (United States)

The Organization for Economic Cooperation and Development (OECD) brings together the governments of countries committed to democracy and the market economy from around the world to support sustainable economic growth.

Volunteering as Red Queen Mechanism for Cooperation in Public Goods Games

Science.gov (United States)

Hauert, Christoph; De Monte, Silvia; Hofbauer, Josef; Sigmund, Karl

2002-05-01

The evolution of cooperation among nonrelated individuals is one of the fundamental problems in biology and social sciences. Reciprocal altruism fails to provide a solution if interactions are not repeated often enough or groups are too large. Punishment and reward can be very effective but require that defectors can be traced and identified. Here we present a simple but effective mechanism operating under full anonymity. Optional participation can foil exploiters and overcome the social dilemma. In voluntary public goods interactions, cooperators and defectors will coexist. We show that this result holds under very diverse assumptions on population structure and adaptation mechanisms, leading usually not to an equilibrium but to an unending cycle of adjustments (a Red Queen type of evolution). Thus, voluntary participation offers an escape hatch out of some social traps. Cooperation can subsist in sizable groups even if interactions are not repeated, defectors remain anonymous, players have no memory, and assortment is purely random.

Interplay between cooperation-enhancing mechanisms in evolutionary games with tag-mediated interactions

Science.gov (United States)

Hadzibeganovic, Tarik; Stauffer, Dietrich; Han, Xiao-Pu

2018-04-01

Cooperation is fundamental for the long-term survival of biological, social, and technological networks. Previously, mechanisms for the enhancement of cooperation, such as network reciprocity, have largely been studied in isolation and with often inconclusive findings. Here, we present an evolutionary, multiagent-based, and spatially explicit computer model to specifically address the interactive interplay between such mechanisms. We systematically investigate the effects of phenotypic diversity, network structure, and rewards on cooperative behavior emerging in a population of reproducing artificial decision makers playing tag-mediated evolutionary games. Cooperative interactions are rewarded such that both the benefits of recipients and costs of donators are affected by the reward size. The reward size is determined by the number of cooperative acts occurring within a given reward time frame. Our computational experiments reveal that small reward frames promote unconditional cooperation in populations with both low and high diversity, whereas large reward frames lead to cycles of conditional and unconditional strategies at high but not at low diversity. Moreover, an interaction between rewards and spatial structure shows that relative to small reward frames, there is a strong difference between the frequency of conditional cooperators populating rewired versus non-rewired networks when the reward frame is large. Notably, in a less diverse population, the total number of defections is comparable across different network topologies, whereas in more diverse environments defections become more frequent in a regularly structured than in a rewired, small-world network of contacts. Acknowledging the importance of such interaction effects in social dilemmas will have inevitable consequences for the future design of cooperation-enhancing protocols in large-scale, distributed, and decentralized systems such as peer-to-peer networks.

Optoelectronic line transmission an introduction to fibre optics

CERN Document Server

Tricker, Raymond L

2013-01-01

Optoelectronic Line Transmission: An Introduction to Fibre Optics presents a basic introduction as well as a background reference manual on fiber optic transmission. The book discusses the basic principles of optical line transmission; the advantages and disadvantages of optical fibers and optoelectronic signalling; the practical applications of optoelectronics; and the future of optoelectronics. The text also describes the theories of optical line transmission; fibers and cables for optical transmission; transmitters including light-emitting diodes and lasers; and receivers including photodi

Origin of the Substitution Mechanism for the Binding of Organic Ligands on the Surface of CsPbBr3 Perovskite Nanocubes.

Science.gov (United States)

Ravi, Vikash Kumar; Santra, Pralay K; Joshi, Niharika; Chugh, Jeetender; Singh, Sachin Kumar; Rensmo, Håkan; Ghosh, Prasenjit; Nag, Angshuman

2017-10-19

Optoelectronic properties of CsPbBr 3 perovskite nanocubes (NCs) depend strongly on the interaction of the organic passivating molecules with the inorganic crystal. To understand this interaction, we employed a combination of synchrotron-based X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR) spectroscopy, and first-principles density functional theory (DFT)-based calculations. Variable energy XPS elucidated the internal structure of the inorganic part in a layer-by-layer fashion, whereas NMR characterized the organic ligands. Our experimental results confirm that oleylammonium ions act as capping ligands by substituting Cs + ions from the surface of CsPbBr 3 NCs. DFT calculations shows that the substitution mechanism does not require much energy for surface reconstruction and, in contrast, stabilizes the nanocrystal by the formation of three hydrogen bonds between the -NH 3 + moiety of oleylammonium and surrounding Br - on the surface of NCs. This substitution mechanism and its origin are in stark contrast to the usual adsorption of organic ligands on the surface of typical NCs.

Light box for investigation of characteristics of optoelectronics detectors

Science.gov (United States)

Szreder, Agnieszka; Mazikowski, Adam

2017-09-01

In this paper, a light box for investigation of characteristics of optoelectronic detectors is described. The light box consists of an illumination device, an optical power sensor and a mechanical enclosure. The illumination device is based on four types of high-power light emitting diodes (LED): white light, red, green and blue. The illumination level can be varied for each LED independently by the driver and is measured by optical power sensor. The mechanical enclosure provides stable mounting points for the illumination device, sensor and the examined detector and protects the system from external light, which would otherwise strongly influence the measurement results. Uniformity of illumination distribution provided by the light box for all colors is good, making the measurement results less dependent on the position of the examined detector. The response of optoelectronic detectors can be investigated using the developed light box for each LED separately or for any combination of up to four LED types. As the red, green and blue LEDs are rather narrow bandwidth sources, spectral response of different detectors can be examined for these wavelength ranges. The described light box can be used for different applications. Its primary use is in a student laboratory setup for investigation of characteristics of optoelectronic detectors. Moreover, it can also be used in various colorimetric or photographic applications. Finally, it will be used as a part of demonstrations from the fields of vision and color, performed during science fairs and outreach activities increasing awareness of optics and photonics.

Russia and the Shanghai Cooperation Organization: Some Elements of Strategy

Directory of Open Access Journals (Sweden)

Mikhail Konarovsky

2016-12-01

Full Text Available The new geopolitical reality that resulted from the dissolution of the USSR created the conditions for the establishment of the Shanghai Cooperation Organisation (SCO in 2001. The successful settlement of border issues between Russia and Kazakhstan, Kirgizstan and Tajikistan as well as with China also facilitated the process. With Uzbekistan joining the “Shanghai Five,” a new regional organization emerged. The SCO’s priorities were in the security sphere and the fight against the proliferation of drugs, illegal migration and organized crime, given the requirements of the times and the specific regional situation (including that in Afghanistan. As one of the active founders, Russia has always taken a leading role in the SCO’s organizational, political and legal formation, including setting specific trends and forms of cooperation, taking common measures, and holding events. During its presidency in 2008–2009 and 2014–2015, Moscow made additional efforts to strengthen cooperation among the SCO members in meeting new regional security challenges and to agree on coordinated positions on the key issues on the international and regional agenda. To increase the SCO’s credibility and political significance, Moscow emphasized its expansion, particularly with regard to the Eurasian Economic Union and the Silk Road Economic Belt. With global political and economic development growing more complicated, in order to revitalize Russia’s role in the SCO it is necessary to strengthen cooperation with China. The strategic character of bilateral relations reaffirmed at the Russian-Chinese summit in the summer of 2016 set a solid foundation.

Study on optoelectronic properties of Spiro-CN for developing an efficient OLED

Science.gov (United States)

Mishra, Ashok Kumar

2018-05-01

There are a class of organic molecules and polymers which exhibit semiconductor behavior because of nearly free conjugate π-electrons. Hopping of these electrons in molecules forms different excited singlet and triplet states named as excitons. Some of these organic molecules can be set to emit photons by triplet-singlet excitonic transition via a process called Thermally Activated Delayed Fluorescence (TADF) which is exploited for designing the Organic Light Emitting diode (OLED.) Spiro-CN (spirobifluorene skeletons) Spiro is one of these reported noble metal-free TADF molecules which offers unique optical and electronic properties arising from the efficient transition and reverse intersystem crossing between the lowest singlet (S) and triplet (T) excited states. Its ability to harvest triplet excitons for fluorescence through facilitated reverse intersystem crossing (T→S) could directly impact their properties and performances, which is attractive for a wide variety of low-cost optoelectronic device. In the present study, the Spiro-CN compounds have been taken up for the investigation of various optoelectronic properties including the thermally activated delayed fluorescence (TADF) by using the Koopmans Method and Density Functional Theory. The present study discusses the utility of the Spiro-CN organic semiconductor as a suitable TADF material essential for developing an efficient Organic Light Emitting Diode (OLED).

Lasers and optoelectronics fundamentals, devices and applications

CERN Document Server

Maini, Anil K

2013-01-01

With emphasis on the physical and engineering principles, this book provides a comprehensive and highly accessible treatment of modern lasers and optoelectronics. Divided into four parts, it explains laser fundamentals, types of lasers, laser electronics & optoelectronics, and laser applications, covering each of the topics in their entirety, from basic fundamentals to advanced concepts. Key features include: exploration of technological and application-related aspects of lasers and optoelectronics, detailing both existing and emerging applications in industry, medical diag

Optimal Contract Design for Cooperative Relay Incentive Mechanism under Moral Hazard

Directory of Open Access Journals (Sweden)

Nan Zhao

2015-01-01

Full Text Available Cooperative relay can effectively improve spectrum efficiency by exploiting the spatial diversity in the wireless networks. However, wireless nodes may acquire different network information with various users’ location and mobility, channels’ conditions, and other factors, which results in asymmetric information between the source and the relay nodes (RNs. In this paper, the relay incentive mechanism between relay nodes and the source is investigated under the asymmetric information. By modelling multiuser cooperative relay as a labour market, a contract model with moral hazard for relay incentive is proposed. To effectively incentivize the potential RNs to participate in cooperative relay, the optimization problems are formulated to maximize the source’s utility while meeting the feasible conditions under both symmetric and asymmetric information scenarios. Numerical simulation results demonstrate the effectiveness of the proposed contract design scheme for cooperative relay.

Regional cooperation on nuclear safety

International Nuclear Information System (INIS)

Kato, W.Y.; Chen, J.H.; Kim, D.H.; Simmons, R.B.V.; Surguri, S.

1985-01-01

A review has been conducted of a number of multi-national and bilateral arrangements between governments and between utility-sponsored organizations which provide the framework for international cooperation in the field of nuclear safety. These arrangements include the routine exchange operational data, experiences, technical reports and regulatory data, provision of special assistance when requested, collaboration in safety research, and the holding of international conferences and seminars. Areas which may be better suited for cooperation on a regional basis are identified. These areas include: exchange of operational data and experience, sharing of emergency planning information, and collaboration in safety research. Mechanisms to initiate regional cooperation in these areas are suggested

An Electronic Structure Approach to Charge Transfer and Transport in Molecular Building Blocks for Organic Optoelectronics

Science.gov (United States)

Hendrickson, Heidi Phillips

A fundamental understanding of charge separation in organic materials is necessary for the rational design of optoelectronic devices suited for renewable energy applications and requires a combination of theoretical, computational, and experimental methods. Density functional theory (DFT) and time-dependent (TD)DFT are cost effective ab-initio approaches for calculating fundamental properties of large molecular systems, however conventional DFT methods have been known to fail in accurately characterizing frontier orbital gaps and charge transfer states in molecular systems. In this dissertation, these shortcomings are addressed by implementing an optimally-tuned range-separated hybrid (OT-RSH) functional approach within DFT and TDDFT. The first part of this thesis presents the way in which RSH-DFT addresses the shortcomings in conventional DFT. Environmentally-corrected RSH-DFT frontier orbital energies are shown to correspond to thin film measurements for a set of organic semiconducting molecules. Likewise, the improved RSH-TDDFT description of charge transfer excitations is benchmarked using a model ethene dimer and silsesquioxane molecules. In the second part of this thesis, RSH-DFT is applied to chromophore-functionalized silsesquioxanes, which are currently investigated as candidates for building blocks in optoelectronic applications. RSH-DFT provides insight into the nature of absorptive and emissive states in silsesquioxanes. While absorption primarily involves transitions localized on one chromophore, charge transfer between chromophores and between chromophore and silsesquioxane cage have been identified. The RSH-DFT approach, including a protocol accounting for complex environmental effects on charge transfer energies, was tested and validated against experimental measurements. The third part of this thesis addresses quantum transport through nano-scale junctions. The ability to quantify a molecular junction via spectroscopic methods is crucial to their

Transferable, conductive TiO{sub 2} nanotube membranes for optoelectronics

Energy Technology Data Exchange (ETDEWEB)

Liu, Guohua [School of Energy and Environment, Anhui University of Technology, Maanshan 243002 (China); Department of Micro and Nano Systems Technology, Vestfold University College, Horten 3184 (Norway); Chen, Ting [School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275 (China); Sun, Yunlan; Chen, Guang [School of Energy and Environment, Anhui University of Technology, Maanshan 243002 (China); Wang, Kaiying, E-mail: Kaiying.Wang@hbv.no [Department of Micro and Nano Systems Technology, Vestfold University College, Horten 3184 (Norway)

2014-08-30

Graphical abstract: An optoelectronic device with vertical architecture offers straight conducting filaments for electron transportation. - Highlights: • Highly porous TiO{sub 2} nanotube membranes are prepared by two-step anodization. • An optoelectronic device is integrated with photocurrent transportation along the nanotube axial. • Straight conducting nano-filaments are beneficial for electron transportation. • Photoconductive performances are demonstrated under front/back-illumination. - Abstract: We report a facile approach for preparing free-standing and crystalline TiO{sub 2} nanotube membranes (TNMs) by taking advantage of differential mechanical stress between two anodic layers. The membrane exhibits visible light transmittance (∼40%) and UV absorption (∼99%) with good flexibility, which is favorable to integrate with substrates in optoelectronics. A sandwich-type device is assembled through stacking the membrane and substrates. The dependence of current-perpendicular-to-membrane vs applied voltage shows a remarkable photoconductive performance for both front and back illumination. The photocurrent value increases ∼2 or 3 orders magnitude under UV light radiation as compared to that in darkness. The photoresponse is arisen from high internal gain caused by hole trapping along the nanotube walls. This work is crucial for understanding intrinsic optical properties of nanostructured membranes.

Optical and Optoelectronic Property Analysis of Nanomaterials inside Transmission Electron Microscope.

Science.gov (United States)

Fernando, Joseph F S; Zhang, Chao; Firestein, Konstantin L; Golberg, Dmitri

2017-12-01

In situ transmission electron microscopy (TEM) allows one to investigate nanostructures at high spatial resolution in response to external stimuli, such as heat, electrical current, mechanical force and light. This review exclusively focuses on the optical, optoelectronic and photocatalytic studies inside TEM. With the development of TEMs and specialized TEM holders that include in situ illumination and light collection optics, it is possible to perform optical spectroscopies and diverse optoelectronic experiments inside TEM with simultaneous high resolution imaging of nanostructures. Optical TEM holders combining the capability of a scanning tunneling microscopy probe have enabled nanomaterial bending/stretching and electrical measurements in tandem with illumination. Hence, deep insights into the optoelectronic property versus true structure and its dynamics could be established at the nanometer-range precision thus evaluating the suitability of a nanostructure for advanced light driven technologies. This report highlights systems for in situ illumination of TEM samples and recent research work based on the relevant methods, including nanomaterial cathodoluminescence, photoluminescence, photocatalysis, photodeposition, photoconductivity and piezophototronics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Organic Synthetic Advanced Materials for Optoelectronic and Energy Applications (at National Taipei University of Technology)

Energy Technology Data Exchange (ETDEWEB)

Yen, Hung-Ju [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Chemistry Division

2016-11-14

These slides cover Hung-Ju Yen's recent work in the synthesis and structural design of functional materials, which were further used for optoelectronic and energy applications, such as lithium ion battery, solar cell, LED, electrochromic, and fuel cells. This was for a job interview at National Taipei University of Technology. The following topics are detailed: current challenges for lithium-ion batteries; graphene, graphene oxide and nanographene; nanographenes with various functional groups; fine tune d-spacing through organic synthesis: varying functional group; schematic view of LIBs; nanographenes as LIB anode; rate performance (charging-discharging); electrochromic technology; electrochromic materials; advantages of triphenylamine; requirement of electrochromic materials for practical applications; low driving voltage and long cycle life; increasing the electroactive sites by multi-step synthetic procedures; synthetic route to starburst triarylamine-based polyamide; electrochromism ranging from visible to NIR region; transmissive to black electrochromism; RGB and CMY electrochromism.

Organic Synthetic Advanced Materials for Optoelectronic and Energy Applications (at Center for Condensed Matter Sciences)

Energy Technology Data Exchange (ETDEWEB)

Yen, Hung-Ju [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Chemistry Division

2016-11-14

These slides cover Hung-Ju Yen's recent work in the synthesis and structural design of functional materials, which were further used for optoelectronic and energy applications, such as lithium ion battery, solar cell, LED, electrochromic, and fuel cells. This was for a job interview at Center for Condensed Matter Sciences. The following topics are detailed: current challenges for lithium-ion batteries; graphene, graphene oxide and nanographene; nanographenes with various functional groups; fine tune d-spacing through organic synthesis: varying functional group; schematic view of LIBs; nanographenes as LIB anode; rate performance (charging-discharging); electrochromic technology; electrochromic materials; advantages of triphenylamine; requirement of electrochromic materials for practical applications; low driving voltage and long cycle life; increasing the electroactive sites by multi-step synthetic procedures; synthetic route to starburst triarylamine-based polyamide; electrochromism ranging from visible to NIR region; transmissive to black electrochromism; RGB and CMY electrochromism.

Organic Synthetic Advanced Materials for Optoelectronic and Energy Applications (at National Sun Yat-sen University) 

Energy Technology Data Exchange (ETDEWEB)

Yen, Hung-Ju [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Chemistry Division

2016-11-14

These slides cover Hung-Ju Yen's recent work in the synthesis and structural design of functional materials, which were further used for optoelectronic and energy applications, such as lithium ion battery, solar cell, LED, electrochromic, and fuel cells. This was for a job interview at National Sun Yat-sen University. The following topics are detailed: current challenges for lithium-ion batteries; graphene, graphene oxide and nanographene; nanographenes with various functional groups; fine tune d-spacing through organic synthesis: varying functional group; schematic view of LIBs; nanographenes as LIB anode; rate performance (charging-discharging); electrochromic technology; electrochromic materials; advantages of triphenylamine; requirement of electrochromic materials for practical applications; low driving voltage and long cycle life; increasing the electroactive sites by multi-step synthetic procedures; synthetic route to starburst triarylamine-based polyamide; electrochromism ranging from visible to NIR region; transmissive to black electrochromism; RGB and CMY electrochromism.

Radiation effects in optoelectronic devices

International Nuclear Information System (INIS)

Barnes, C.E.; Wiczer, J.J.

1984-05-01

Purpose of this report is to provide not only a summary of radiation damage studies at Sandia National Laboratories, but also of those in the literature on the components of optoelectronic systems: light emitting diodes (LEDs), laser diodes, photodetectors, optical fibers, and optical isolators. This review of radiation damage in optoelectronic components is structured according to device type. In each section, a brief discussion of those device properties relevant to radiation effects is given

Temperature-Induced Lattice Relaxation of Perovskite Crystal Enhances Optoelectronic Properties and Solar Cell Performance

KAUST Repository

Banavoth, Murali; Yengel, Emre; Peng, Wei; Chen, Zhijie; Alias, Mohd Sharizal; Alarousu, Erkki; Ooi, Boon S.; Burlakov, Victor; Goriely, Alain; Eddaoudi, Mohamed; Bakr, Osman; Mohammed, Omar F.

2016-01-01

Hybrid organic-inorganic perovskite crystals have recently become one of the most important classes of photoactive materials in the solar cell and optoelectronic communities. Albeit improvements have focused on state-of-the-art technology including

SEARCH OF MECHANISMS AND FORMS OF COOPERATION INTERACTION IN CHAINS OF DELIVERIES

Directory of Open Access Journals (Sweden)

Arseny V. Brykin

2015-01-01

Full Text Available In article features of development of the Russian model of mixed economy and integration of the private, public and state beginnings, and also conditions of financial and economic uncertainty which introduced the additional, difficult operated risks and problems to domestic industrial production are considered. According to the author, in modern conditions, considering external calls and threats, and also internal risks, coordination in cooperation communications is of particular importance. Exactly here the greatest extent of development of cooperation communications and tools of an innovative paradigm of development of business is required. The author gives examples of mechanisms and forms of cooperation interaction in chains of deliveries and offers coordination options in cooperation communications in the conditions of an economic crisis. 

Cooperation-Controlled Learning for Explicit Class Structure in Self-Organizing Maps

Science.gov (United States)

Kamimura, Ryotaro

2014-01-01

We attempt to demonstrate the effectiveness of multiple points of view toward neural networks. By restricting ourselves to two points of view of a neuron, we propose a new type of information-theoretic method called “cooperation-controlled learning.” In this method, individual and collective neurons are distinguished from one another, and we suppose that the characteristics of individual and collective neurons are different. To implement individual and collective neurons, we prepare two networks, namely, cooperative and uncooperative networks. The roles of these networks and the roles of individual and collective neurons are controlled by the cooperation parameter. As the parameter is increased, the role of cooperative networks becomes more important in learning, and the characteristics of collective neurons become more dominant. On the other hand, when the parameter is small, individual neurons play a more important role. We applied the method to the automobile and housing data from the machine learning database and examined whether explicit class boundaries could be obtained. Experimental results showed that cooperation-controlled learning, in particular taking into account information on input units, could be used to produce clearer class structure than conventional self-organizing maps. PMID:25309950

Cooperation-Controlled Learning for Explicit Class Structure in Self-Organizing Maps

Directory of Open Access Journals (Sweden)

Ryotaro Kamimura

2014-01-01

Full Text Available We attempt to demonstrate the effectiveness of multiple points of view toward neural networks. By restricting ourselves to two points of view of a neuron, we propose a new type of information-theoretic method called “cooperation-controlled learning.” In this method, individual and collective neurons are distinguished from one another, and we suppose that the characteristics of individual and collective neurons are different. To implement individual and collective neurons, we prepare two networks, namely, cooperative and uncooperative networks. The roles of these networks and the roles of individual and collective neurons are controlled by the cooperation parameter. As the parameter is increased, the role of cooperative networks becomes more important in learning, and the characteristics of collective neurons become more dominant. On the other hand, when the parameter is small, individual neurons play a more important role. We applied the method to the automobile and housing data from the machine learning database and examined whether explicit class boundaries could be obtained. Experimental results showed that cooperation-controlled learning, in particular taking into account information on input units, could be used to produce clearer class structure than conventional self-organizing maps.

Genetic architecture promotes the evolution and maintenance of cooperation.

Directory of Open Access Journals (Sweden)

Antoine Frénoy

Full Text Available When cooperation has a direct cost and an indirect benefit, a selfish behavior is more likely to be selected for than an altruistic one. Kin and group selection do provide evolutionary explanations for the stability of cooperation in nature, but we still lack the full understanding of the genomic mechanisms that can prevent cheater invasion. In our study we used Aevol, an agent-based, in silico genomic platform to evolve populations of digital organisms that compete, reproduce, and cooperate by secreting a public good for tens of thousands of generations. We found that cooperating individuals may share a phenotype, defined as the amount of public good produced, but have very different abilities to resist cheater invasion. To understand the underlying genetic differences between cooperator types, we performed bio-inspired genomics analyses of our digital organisms by recording and comparing the locations of metabolic and secretion genes, as well as the relevant promoters and terminators. Association between metabolic and secretion genes (promoter sharing, overlap via frame shift or sense-antisense encoding was characteristic for populations with robust cooperation and was more likely to evolve when secretion was costly. In mutational analysis experiments, we demonstrated the potential evolutionary consequences of the genetic association by performing a large number of mutations and measuring their phenotypic and fitness effects. The non-cooperating mutants arising from the individuals with genetic association were more likely to have metabolic deleterious mutations that eventually lead to selection eliminating such mutants from the population due to the accompanying fitness decrease. Effectively, cooperation evolved to be protected and robust to mutations through entangled genetic architecture. Our results confirm the importance of second-order selection on evolutionary outcomes, uncover an important genetic mechanism for the evolution and

International co-operation

International Nuclear Information System (INIS)

1998-01-01

In this part the are reviewed: Co-operation with IAEA; Participation of the Slovakia on the 41 st session of the General Conference; The comprehensive Nuclear-Test-Ban Treaty Organization; Co-operation with the Organization for Economic Co-operation and Development; co-operation with the European Commission; Fulfillment of obligations resulting from the international contracting documents

Beyond Donor-Acceptor (D-A) Approach: Structure-Optoelectronic Properties-Organic Photovoltaic Performance Correlation in New D-A1 -D-A2 Low-Bandgap Conjugated Polymers.

Science.gov (United States)

Chochos, Christos L; Drakopoulou, Sofia; Katsouras, Athanasios; Squeo, Benedetta M; Sprau, Christian; Colsmann, Alexander; Gregoriou, Vasilis G; Cando, Alex-Palma; Allard, Sybille; Scherf, Ullrich; Gasparini, Nicola; Kazerouni, Negar; Ameri, Tayebeh; Brabec, Christoph J; Avgeropoulos, Apostolos

2017-04-01

Low-bandgap near-infrared polymers are usually synthesized using the common donor-acceptor (D-A) approach. However, recently polymer chemists are introducing more complex chemical concepts for better fine tuning of their optoelectronic properties. Usually these studies are limited to one or two polymer examples in each case study so far, though. In this study, the dependence of optoelectronic and macroscopic (device performance) properties in a series of six new D-A 1 -D-A 2 low bandgap semiconducting polymers is reported for the first time. Correlation between the chemical structure of single-component polymer films and their optoelectronic properties has been achieved in terms of absorption maxima, optical bandgap, ionization potential, and electron affinity. Preliminary organic photovoltaic results based on blends of the D-A 1 -D-A 2 polymers as the electron donor mixed with the fullerene derivative [6,6]-phenyl-C 71 -butyric acid methyl ester demonstrate power conversion efficiencies close to 4% with short-circuit current densities (J sc ) of around 11 mA cm -2 , high fill factors up to 0.70, and high open-circuit voltages (V oc s) of 0.70 V. All the devices are fabricated in an inverted architecture with the photoactive layer processed in air with doctor blade technique, showing the compatibility with roll-to-roll large-scale manufacturing processes. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ultrafast Graphene Photonics and Optoelectronics

Science.gov (United States)

2017-04-14

AFRL-AFOSR-JP-TR-2017-0032 Ultrafast Graphene Photonics and Optoelectronics Kuang-Hsiung Wu National Chiao Tung University Final Report 04/14/2017...DATES COVERED (From - To) 18 Apr 2013 to 17 Apr 2016 4. TITLE AND SUBTITLE Ultrafast Graphene Photonics and Optoelectronics 5a.  CONTRACT NUMBER 5b...Prescribed by ANSI Std. Z39.18 Final Report for AOARD Grant FA2386-13-1-4022 “Ultrafast Graphene Photonics and Optoelectronics” Date May 23th, 2016

Organization and mechanization of maintenance operations at NPPs with the WWER type reactors

International Nuclear Information System (INIS)

Titov, A.A.

1983-01-01

The structure of capital investments defining organization and mechanization of maintepance operations at NPPs with the WWER type reactors is analyzed. The trends in development of optimum decisions for organization and mechanization of repair obs at NPPs being designed taking into account the prospects of nuclear powep enginerning development, the system of NPP maintenance servicing, as well as the structure of repair-productive capacities are discussed. On the basis of the analysis of the data obtained in designing the Zaporozhskaya NPP it is shown that the capital investments for organizing and mechanization of maintenance operations at the unified NPP site with four WWER-1000 reactors reach nearly 18 roubles/kW. A conclusion is drawn that at present the design of an NPP with the WWER-1000 reactor totally meets the requirements of realization of periodic maintenance operations. It is advisable to cooperate the NPP management with that of a thermal power station from the viewpoint of using manpower, which would improve the operating conditions and labour productivity of workers engaged in repair and, consequently, reduce the capital investments and repair expenditures

Optoelectronics technologies for Virtual Reality systems

Science.gov (United States)

Piszczek, Marek; Maciejewski, Marcin; Pomianek, Mateusz; Szustakowski, Mieczysław

2017-08-01

Solutions in the field of virtual reality are very strongly associated with optoelectronic technologies. This applies to both process design and operation of VR applications. Technologies such as 360 cameras and 3D scanners significantly improve the design work. What is more, HMD displays with high field of view or optoelectronic Motion Capture systems and 3D cameras guarantee an extraordinary experience in immersive VR applications. This article reviews selected technologies from the perspective of their use in a broadly defined process of creating and implementing solutions for virtual reality. There is also the ability to create, modify and adapt new approaches that show team own work (SteamVR tracker). Most of the introduced examples are effectively used by authors to create different VR applications. The use of optoelectronic technology in virtual reality is presented in terms of design and operation of the system as well as referring to specific applications. Designers and users of VR systems should take a close look on new optoelectronics solutions, as they can significantly contribute to increased work efficiency and offer completely new opportunities for virtual world reception.

Study of various n-type organic semiconductors on ultraviolet detective and electroluminescent properties of optoelectronic integrated device

Science.gov (United States)

Deng, Chaoxu; Shao, Bingyao; Zhao, Dan; Zhou, Dianli; Yu, Junsheng

2017-11-01

Organic optoelectronic integrated device (OID) with both ultraviolet (UV) detective and electroluminescent (EL) properties was fabricated by using a thermally activated delayed fluorescence (TADF) semiconductor of (4s, 6s)-2,4,5,6-tetra(9H-carbazol-9-yl)isophthalonitrile (4CzIPN) as an emitter. The effect of five kinds of n-type organic semiconductors (OSCs) on the enhancement of UV detective and EL properties of OID was systematically studied. The result shows that two orders of magnitude in UV detectivity from 109 to 1011 Jones and 3.3 folds of luminance from 2499 to 8233 cd m-2 could be achieved. The result shows that not only the difference of lowest unoccupied molecular orbital (LUMO) between active layer and OSC but also the variety of electron mobility have a significant effect on the UV detective and EL performance through adjusting electron injection/transport. Additionally, the optimized OSC thickness is beneficial to confine the leaking of holes from the active layer to cathode, leading to the decrease of dark current for high detective performance. This work provides a useful method on broadening OSC material selection and device architecture construction for the realization of high performance OID.

Volunteering as Red Queen mechanism for cooperation in public goods games

DEFF Research Database (Denmark)

Hauert, C.; De Monte, Silvia; Hofbauer, J.

2002-01-01

The evolution of cooperation among nonrelated individuals is one of the fundamental problems in biology and social sciences. Reciprocal altruism fails to provide a solution if interactions are not repeated often enough or groups are too large. Punishment and reward can be very effective but require...... that defectors can be traced and identified. Here we present a simple but effective mechanism operating under full anonymity. Optional participation can foil exploiters and overcome the social dilemma. In voluntary public goods interactions, cooperators and defectors will coexist. We show that this result holds...

Studies on the optoelectronic properties of the thermally evaporated tin-doped indium oxide nanostructures

Energy Technology Data Exchange (ETDEWEB)

Pan, Ko-Ying [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan, ROC (China); Lin, Liang-Da [Institute of Materials Science and Nanotechnology, Chinese Culture University, Taipei 111, Taiwan, ROC (China); Chang, Li-Wei [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan, ROC (China); Shih, Han C., E-mail: hcshih@mx.nthu.edu.tw [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan, ROC (China); Institute of Materials Science and Nanotechnology, Chinese Culture University, Taipei 111, Taiwan, ROC (China)

2013-05-15

Indium oxide (In{sub 2}O{sub 3}) nanorods, nanotowers and tin-doped (Sn:In = 1:100) indium oxide (ITO) nanorods have been fabricated by thermal evaporation. The morphology, microstructure and chemical composition of these three nanoproducts are characterized by FE-SEM, HRTEM and XPS. To further investigate the optoelectronic properties, the I–V curves and cathodoluminescence (CL) spectra are measured. The electrical resistivity of In{sub 2}O{sub 3} nanorods, nanotowers and ITO nanorods are 1.32 kΩ, 0.65 kΩ and 0.063 kΩ, respectively. CL spectra of these three nanoproducts clearly indicate that tin-doped (Sn:In = 1:100) indium oxide (ITO) nanorods cause a blue shift. No doubt ITO nanorods obtain the highest performance among these three nanoproducts, and this also means that Sn-doped In{sub 2}O{sub 3} nanostructures would be the best way to enhance the optoelectronic properties. Additionally, the growing mechanism and the optoelectronic properties of these three nanostructures are discussed. This study is beneficial to the applications of In{sub 2}O{sub 3} nanorods, nanotowers and ITO nanorods in optoelectronic nanodevices.

New Cooperative Mechanisms of Low Energy Nuclear Reactions Using Superlow Energy External Fields

OpenAIRE

Gareev, F. A.; Zhidkova, I. E.

2005-01-01

We proposed a new mechanism of LENR: cooperative processes in whole system - nuclei+atoms+condensed matter can occur at smaller threshold then corresponding ones on free constituents. The cooperative processes can be induced and enhanced by low energy external fields. The excess heat is the emission of internal energy and transmutations at LENR are the result of redistribution inner energy of whole system.

States, Social Capital and Cooperation

DEFF Research Database (Denmark)

Anthony, Denise L.; Campbell, John L.

2011-01-01

This paper reflects on Elinor Ostrom’s classic book, Governing the Commons, and much work in sociology, political science and organization studies that has appeared since its publication. We do so in order to expand our understanding of the conditions under which cooperation occurs resulting...... in the production of collective goods. We explore two issues that were underdeveloped in her book that have subsequently received much attention. First, we discuss how states can facilitate cooperative behavior short of coercively imposing it on actors. Second, we discuss how social capital can facilitate...... or undermine cooperative behavior. In both cases we focus on the important mechanisms by which each one contributes to the development of cooperative behavior and collective goods. We conclude by extending our arguments to a brief analysis of one of the world’s newest and largest collective goods...

Innovative Mechanism of Rural Organization Based on Self-Organization

Institute of Scientific and Technical Information of China (English)

2011-01-01

The paper analyzes the basic situation of the formation of innovative rural organizations with the form of self-organization;reveals the features of self-organization,including the four aspects of openness of rural organization,innovation of rural organization far away from equilibrium,the non-linear response mechanism of rural organization innovation and the random rise and fall of rural organization innovation.The evolution mechanism of rural organization innovation is revealed according to the growth stage,the ideal stage,the decline and the fall stage.The paper probes into the basic restriction mechanism of the self-organization evaluation of rural organization from three aspects,including target recognition,path dependence and knowledge sharing.The basic measures on cultivating the innovative mechanism of rural organization are put forward.Firstly,constructing the dissipative structure of rural organization innovation;secondly,cultivating the dynamic study capability of rural organization innovation system;thirdly,selecting the step-by-step evolution strategy of rural organization innovation system.

Architecture for self-organizing, co-operative and robust building automation systems

NARCIS (Netherlands)

Bernier, F.; Ploennigs, J.; Pesch, D.; Lesecq, S.; Basten, T.; Boubekeur, M.; Denteneer, T.J.J.; Oltmanns, F.; Lehmann, M.; Mai, Linh Tuan; Mc Gibney, A.; Rea, S.; Pacull, F.; Guyon-Gardeux, C.; Ducreux, L.F.; Thior, S.; Hendriks, M.; Verriet, J.H.; Fedor, S.

2013-01-01

This paper provides an overview of the architecture for self-organizing, co-operative and robust Building Automation Systems (BAS) proposed by the EC funded FP7 SCUBA1 project. We describe the current situation in monitoring and control systems and outline the typical stakeholders involved in the

Architecture for self-organizing, co-operative and robust Building Automation Systems

NARCIS (Netherlands)

Bernier, F.; Ploennigs, J.; Pesch, D.; Lesecq, S.; Basten, T.; Boubekeur, M.; Denteneer, D.; Oltmanns, F.; Bonnard, F.; Lehmann, M.; Mai, T.L.; McGibney, A.; Rea, S.; Pacull, F.; Guyon-Gardeux, C.; Ducreux, L.F.; Thior, S.; Hendriks, M.; Verriet, J.; Fedor, S.

2013-01-01

This paper provides an overview of the architecture for self-organizing, co-operative and robust Building Automation Systems (BAS) proposed by the EC funded FP7 SCUBA1 project. We describe the current situation in monitoring and control systems and outline the typical stakeholders involved in the

The Texts of the Agency's Co-operation Agreements with Regional Intergovernmental Organizations

International Nuclear Information System (INIS)

1969-01-01

The text of the Agency's agreement for co-operation with the Organization of African Unity (OAU) is reproduced in this document for the information of all Members. The agreement entered into force on 26 March 1969

Optoelectronic pH Meter: Further Details

Science.gov (United States)

Jeevarajan, Antony S.; Anderson, Mejody M.; Macatangay, Ariel V.

2009-01-01

A collection of documents provides further detailed information about an optoelectronic instrument that measures the pH of an aqueous cell-culture medium to within 0.1 unit in the range from 6.5 to 7.5. The instrument at an earlier stage of development was reported in Optoelectronic Instrument Monitors pH in a Culture Medium (MSC-23107), NASA Tech Briefs, Vol. 28, No. 9 (September 2004), page 4a. To recapitulate: The instrument includes a quartz cuvette through which the medium flows as it is circulated through a bioreactor. The medium contains some phenol red, which is an organic pH-indicator dye. The cuvette sits between a light source and a photodetector. [The light source in the earlier version comprised red (625 nm) and green (558 nm) light-emitting diodes (LEDs); the light source in the present version comprises a single green- (560 nm)-or-red (623 nm) LED.] The red and green are repeatedly flashed in alternation. The responses of the photodiode to the green and red are processed electronically to obtain the ratio between the amounts of green and red light transmitted through the medium. The optical absorbance of the phenol red in the green light varies as a known function of pH. Hence, the pH of the medium can be calculated from the aforesaid ratio.

An introduction to optoelectronic sensors

CERN Document Server

Tajani, Antonella; Cutolo, Antonello

2009-01-01

This invaluable book offers a comprehensive overview of the technologies and applications of optoelectronic sensors. Based on the R&D experience of more than 70 engineers and scientists, highly representative of the Italian academic and industrial community in this area, this book provides a broad and accurate description of the state-of-the-art optoelectronic technologies for sensing. The most innovative approaches, such as the use of photonic crystals, squeezed states of light and microresonators for sensing, are considered. Application areas range from environment to medicine and healthcare

Tissue organization by cadherin adhesion molecules: dynamic molecular and cellular mechanisms of morphogenetic regulation

Science.gov (United States)

Niessen, Carien M.; Leckband, Deborah; Yap, Alpha S.

2013-01-01

This review addresses the cellular and molecular mechanisms of cadherin-based tissue morphogenesis. Tissue physiology is profoundly influenced by the distinctive organizations of cells in organs and tissues. In metazoa, adhesion receptors of the classical cadherin family play important roles in establishing and maintaining such tissue organization. Indeed, it is apparent that cadherins participate in a range of morphogenetic events that range from support of tissue integrity to dynamic cellular rearrangements. A comprehensive understanding of cadherin-based morphogenesis must then define the molecular and cellular mechanisms that support these distinct cadherin biologies. Here we focus on four key mechanistic elements: the molecular basis for adhesion through cadherin ectodomains; the regulation of cadherin expression at the cell surface; cooperation between cadherins and the actin cytoskeleton; and regulation by cell signaling. We discuss current progress and outline issues for further research in these fields. PMID:21527735

Pi-pi Stacking Mediated Cooperative Mechanism for Human Cytochrome P450 3A4

Directory of Open Access Journals (Sweden)

Botao Fa

2015-04-01

Full Text Available Human Cytochrome P450 3A4 (CYP3A4 is an important member of the cytochrome P450 superfamily with responsibility for metabolizing ~50% of clinical drugs. Experimental evidence showed that CYP3A4 can adopt multiple substrates in its active site to form a cooperative binding model, accelerating substrate metabolism efficiency. In the current study, we constructed both normal and cooperative binding models of human CYP3A4 with antifungal drug ketoconazoles (KLN. Molecular dynamics simulation and free energy calculation were then carried out to study the cooperative binding mechanism. Our simulation showed that the second KLN in the cooperative binding model had a positive impact on the first one binding in the active site by two significant pi-pi stacking interactions. The first one was formed by Phe215, functioning to position the first KLN in a favorable orientation in the active site for further metabolism reactions. The second one was contributed by Phe304. This pi-pi stacking was enhanced in the cooperative binding model by the parallel conformation between the aromatic rings in Phe304 and the dioxolan moiety of the first KLN. These findings can provide an atomic insight into the cooperative binding in CYP3A4, revealing a novel pi-pi stacking mechanism for drug-drug interactions.

Choosing the cooperative option

Energy Technology Data Exchange (ETDEWEB)

English, G. (National Rural Electric Cooperative Association (United States))

1999-06-01

Cooperatives do not ask to be exempted from the law. They do ask that laws and regulations be designed to allow them to meet the needs of their consumer-owners in accordance with cooperative principles, at a time that the marginal consumers being abandoned by for-profit utilities may be ready to gravitate toward cooperatives. The cooperative principles are worth reviewing because they explain the focus on the consumer and the cooperative concept of service: cooperatives are voluntary organizations, open to all persons able to use their services and willing to accept the responsibilities of membership; cooperatives are democratic organizations controlled by their members, who actively participate in setting policies and making decisions, the elected representatives are accountable to the membership; members contribute equitably to, and democratically control, the capital of their cooperative; cooperatives are autonomous, self-help organizations controlled by their members, if they enter into agreements with other organizations, including governments, they do so on terms that ensure democratic control by their members and maintain their cooperative autonomy; cooperatives provide education and training for their members, elected representatives, managers, and employees so they can contribute effectively to the development of their cooperatives, they inform the general public, particularly young people and opinion leaders, about the nature and benefits of cooperation; cooperatives serve their members most effectively and strength the cooperative movement by working together through local, national, regional, and international structures; and while focusing on member needs, cooperatives work for the sustainable development of their communities through policies accepted by their members.

Problems of systems dataware using optoelectronic measuring means of linear displacement

Science.gov (United States)

Bazykin, S. N.; Bazykina, N. A.; Samohina, K. S.

2017-10-01

Problems of the dataware of the systems with the use of optoelectronic means of the linear displacement are considered in the article. The classification of the known physical effects, realized by the means of information-measuring systems, is given. The organized analysis of information flows in technical systems from the standpoint of determination of inaccuracies of measurement and management was conducted. In spite of achieved successes in automation of machine-building and instruments-building equipment in the field of dataware of the technical systems, there are unresolved problems, concerning the qualitative aspect of the production process. It was shown that the given problem can be solved using optoelectronic lazer information-measuring systems. Such information-measuring systems are capable of not only executing the measuring functions, but also solving the problems of management and control during processing, thereby guaranteeing the quality of final products.

Cooperative Enhancement Mechanisms of Low Energy Nuclear Reactions Using Superlow Energy External Fields

OpenAIRE

Gareev, F. A.; Zhidkova, I. E.

2006-01-01

We proposed a new mechanism of LENR: cooperative processes in whole system - nuclei+atoms+condensed matter can occur at smaller threshold energies then corresponding ones on free constituents. The cooperative processes can be induced and enhanced by low energy external fields. The excess heat is the emission of internal energy and transmutations at LENR are the result of redistribution inner energy of whole system.

Cooperative Learning in a Soil Mechanics Course at Undergraduate Level

Science.gov (United States)

Pinho-Lopes, M.; Macedo, J.; Bonito, F.

2011-01-01

The implementation of the Bologna Process enforced a significant change on traditional learning models, which were focused mainly on the transmission of knowledge. The results obtained in a first attempt at implementation of a cooperative learning model in the Soil Mechanics I course of the Department of Civil Engineering of the University of…

Size-tunable band alignment and optoelectronic properties of transition metal dichalcogenide van der Waals heterostructures

Science.gov (United States)

Zhao, Yipeng; Yu, Wangbing; Ouyang, Gang

2018-01-01

2D transition metal dichalcogenide (TMDC)-based heterostructures exhibit several fascinating properties that can address the emerging market of energy conversion and storage devices. Current achievements show that the vertical stacked TMDC heterostructures can form type II band alignment and possess significant optoelectronic properties. However, a detailed analytical understanding of how to quantify the band alignment and band offset as well as the optimized power conversion efficiency (PCE) is still lacking. Herein, we propose an analytical model to exhibit the PCEs of TMDC van der Waals (vdW) heterostructures and explore the intrinsic mechanism of photovoltaic conversion based on the detailed balance principle and atomic-bond-relaxation correlation mechanism. We find that the PCE of monolayer MoS2/WSe2 can be up to 1.70%, and that of the MoS2/WSe2 vdW heterostructures increases with thickness, owing to increasing optical absorption. Moreover, the results are validated by comparing them with the available evidence, providing realistic efficiency targets and design principles. Highlights • Both electronic and optoelectronic models are developed for vertical stacked MoS2/WSe2 heterostructures. • The underlying mechanism on size effect of electronic and optoelectronic properties for vertical stacked MoS2/WSe2 heterostructures is clarified. • The macroscopically measurable quantities and the microscopical bond identities are connected.

State and regional systems of accounting for and control of nuclear materials cooperation between international, regional and states safeguards organizations: An evolving issue

International Nuclear Information System (INIS)

Fernández Moreno, Sonia

2011-01-01

Cooperation between the IAEA, States and regional organizations is increasingly important to ensure effective accountancy and control of nuclear material in peaceful uses. The IAEA, SAGSI2 and institutions such INMM3 and ESARDA4 have recognized the relevance and the evolving role that SSAC5 and regional organizations play to this aim. In this context, it is important to take steps to ensure the effectiveness of the system and the optimal level of relationship between these organizations so as to maximize the benefits for each party, particularly in those cases where well developed systems exist. Moreover, expansion of nuclear energy requires concerted efforts towards building competence in safeguards in all relevant States. This is also important with respect to other aspects of nonproliferation. In this scenario there is agreement on the need to have effective state organizations that fulfill international safeguards and other security obligations. However, the roles and duties of SSAC and the possible scope of cooperation between the IAEA and SSAC are still under evolution. This paper discusses possible ways and means to build competence in safeguards and how the international community could be more proactive in establishing a framework including the various dimensions of the cooperation in safeguards and other security matters between all parties concerned. The establishment of a forum and a network of interested parties under the auspice of interested organizations could be one mechanism to exchange best practices and experiences. (authors)

Curriculum design and German student exchange for Sino-German Bachelor program majored in optoelectronics engineering

Science.gov (United States)

Zheng, Jihong; Fuhrmann, Thomas; Xu, Boqing; Schreiner, Rupert; Jia, Hongzhi; Zhang, Wei; Wang, Ning; Seebauer, Gudrun; Zhu, Jiyan

2017-08-01

Different higher education backgrounds in China and Germany led to challenges in the curriculum design at the beginning of our cooperative bachelor program in Optoelectronics Engineering. We see challenges in different subject requirements from both sides and in the German language requirements for Chinese students. The curriculum was optimized according to the ASIIN criteria, which makes it acceptable and understandable by both countries. German students are integrated into the Chinese class and get the same lectures like their Chinese colleagues. Intercultural and curriculum challenges are successfully solved. The results are summarized to provide an example for other similar international programs.

Cooperative Control of Active Power Filters in Power Systems without Mutual Communication

Czech Academy of Sciences Publication Activity Database

Tlustý, J.; Škramlík, Jiří; Švec, J.; Valouch, Viktor

2010-01-01

Roč. 2010, č. 517184 (2010), s. 1-13 ISSN 1024-123X R&D Projects: GA AV ČR IAA200760703 Institutional research plan: CEZ:AV0Z20570509 Keywords : active power filter * power system * wireless cooperation Subject RIV: JA - Electronics ; Optoelectronics, Electric al Engineering Impact factor: 0.689, year: 2010 http://www.hindawi.com/journals/mpe/2010/517184.html

Non-cooperative planning theory

CERN Document Server

Bogetoft, Peter

1994-01-01

Planning in a general sense is concerned with the design of communication and decision making mechanisms in organizations where information and choice are decentralized. Non-cooperative planning theory as it is developed in this book treats the incentive aspects hereof. It stresses how strategic behavior and opportunism may impede planning, and how this can be coped with via the organization of communication and decision making, the design of information and control systems, and the development of incentive schemes. In particular, the book contains a thorough investigation of incentive provision in information production.

Microfluidic optoelectronic sensor for salivary diagnostics of stomach cancer.

Science.gov (United States)

Zilberman, Yael; Sonkusale, Sameer R

2015-05-15

We present a microfluidic optoelectronic sensor for saliva diagnostics with a potential application for non-invasive early diagnosis of stomach cancer. Stomach cancer is the second most common cause of cancer-related deaths in the world. The primary identified cause is infection by a gram-negative bacterium Helicobacter pylori. These bacteria secrete the enzyme urease that converts urea into carbon dioxide (CO2) and ammonia (NH3), leading to their elevated levels in breath and body fluids. The proposed optoelectronic sensor will detect clinically relevant levels of CO2 and NH3 in saliva that can potentially be used for early diagnosis of stomach cancer. The sensor is composed of the embedded in a microfluidic device array of microwells filled with ion-exchange polymer microbeads doped with various organic dyes. The optical response of this unique highly diverse sensor is monitored over a broad spectrum, which provides a platform for cross-reactive sensitivity and allows detection of CO2 and NH3 in saliva at ppm levels. Copyright © 2014 Elsevier B.V. All rights reserved.

Dual-scale topology optoelectronic processor.

Science.gov (United States)

Marsden, G C; Krishnamoorthy, A V; Esener, S C; Lee, S H

1991-12-15

The dual-scale topology optoelectronic processor (D-STOP) is a parallel optoelectronic architecture for matrix algebraic processing. The architecture can be used for matrix-vector multiplication and two types of vector outer product. The computations are performed electronically, which allows multiplication and summation concepts in linear algebra to be generalized to various nonlinear or symbolic operations. This generalization permits the application of D-STOP to many computational problems. The architecture uses a minimum number of optical transmitters, which thereby reduces fabrication requirements while maintaining area-efficient electronics. The necessary optical interconnections are space invariant, minimizing space-bandwidth requirements.

FABRICATION, MORPHOLOGICAL AND OPTOELECTRONIC ...

African Journals Online (AJOL)

2014-12-31

Dec 31, 2014 ... porous silicon has better optoelectronic properties than bulk .... Measurement: The morphological properties of PS layer such as nanocrystalline size, the .... excess carrier removal by internal recombination and diffusion.

The effect of heterogeneous defectors on the evolution of public cooperation

Science.gov (United States)

Chen, Tong; Hu, Xuezhi; Wang, Yongjie; Wang, Le

2018-06-01

In recent years,more and more private capital join the construction of cultural facilities and the organization of cultural activities in China. Actually, the organization of cultural activities by crowd-funding mechanism is a kind of multi-player game. Not all players who donate different amount of money are real cooperators. In fact, some cunning defectors may donate a little money to avoid the gossip and punishment. This part of people are very tricky. They could be seen as heterogeneous defectors. The role of heterogeneous defectors is investigated in cooperative behaviors of complex social network. Numerical results show that heterogeneous defectors could be a buffer for maintaining the public pool when synergy factor is low in public goods game (PGG). It is relatively easy to be cooperators for heterogeneous defectors when synergy factor is high in PGG. To better improve cooperation, punishment towards heterogeneous defectors and complete defectors is introduced. We are glad to find that when the defectors' loss is equal to or larger than the altruistic cooperators' punishment cost, the mechanism could make great effect. In addition, the role of heterogeneous defectors depends on the relationship between the punishment cost and the defectors' loss.

Innovative Mechanism of Rural Organization Based on Self-Organization

OpenAIRE

Wang, Xing jin; Gao, Bing

2011-01-01

The paper analyzes the basic situation for the formation of innovative rural organizations with the form of self-organization; revels the features of self-organization, including the four aspects of openness of rural organization, innovation of rural organization is far away from equilibrium, the non-linear response mechanism of rural organization innovation and the random rise and fall of rural organization innovation. The evolution mechanism of rural organization innovation is reveled accor...

International cooperation

International Nuclear Information System (INIS)

1996-01-01

In 1995, Nuclear Regulatory Authority of the Slovak Republic (NRA SR) ensured foreign cooperation particularly in the frame of the Slovak Republic is membership in the IAEA, as well as cooperation with the Nuclear Energy Agency of the Organization for Economic Cooperation and Development (OECD NEA), cooperation with European Union in the frame of PHARE programmes, and intergovernmental cooperation and cooperation among nuclear regulatory authorities. With respect to an international importance, prestige and a wide-scope possibilities of a technical assistance , either a direct one (expert assessments, technology supplies, work placement, scientific trips, training courses) or indirect one (participation at various conferences, seminars, technical committees, etc), the most important cooperation with the IAEA in Vienna. In 1994, the Slovak Republic, was elected to the Board Governors, the represent the group of Eastern European countries. The Slovak Government entrusted the NRA SR's Chairman with representing the Slovak Republic in the Board of Governors. Owing to a good name of Slovakia was elected to the one of two Vice-Chairmen of the Board of Governors at the 882-nd session on the Board. IAEA approved and developed 8 national projects for Slovakia in 1995. Generally, IAEA is contracting scientific contracts with research institutes, nuclear power plants and other organizations. Slovak organizations used these contracts as complementary funding of their tasks. In 1995, there were 12 scientific contracts in progress, or approved respectively. Other international activities of the NRA SR, international co-operations as well as foreign affairs are reported

Perovskite Materials: Solar Cell and Optoelectronic Applications

Energy Technology Data Exchange (ETDEWEB)

Yang, Bin [ORNL; Geohegan, David B [ORNL; Xiao, Kai [ORNL

2017-01-01

Hybrid organometallic trihalide perovskites are promising candidates in the applications for next-generation, high-performance, low-cost optoelectronic devices, including photovoltaics, light emitting diodes, and photodetectors. Particularly, the solar cells based on this type of materials have reached 22% lab scale power conversion efficiency in only about seven years, comparable to the other thin film photovoltaic technologies. Hybrid perovskite materials not only exhibit superior optoelectronic properties, but also show many interesting physical properties such as ion migration and defect physics, which may allow the exploration of more device functionalities. In this article, the fundamental understanding of the interrelationships between crystal structure, electronic structure, and material properties is discussed. Various chemical synthesis and processing methods for superior device performance in solar cells and optoelectronic devices are reviewed.

Mechanics of bioinspired imaging systems

Directory of Open Access Journals (Sweden)

Zhengwei Li

2016-01-01

Full Text Available Imaging systems in nature have attracted a lot of research interest due to their superior optical and imaging characteristics. Recent advancements in materials science, mechanics, and stretchable electronics have led to successful development of bioinspired cameras that resemble the structures and functions of biological light-sensing organs. In this review, we discuss some recent progresses in mechanics of bioinspired imaging systems, including tunable hemispherical eyeball camera and artificial compound eye camera. The mechanics models and results reviewed in this article can provide efficient tools for design and optimization of such systems, as well as other related optoelectronic systems that combine rigid elements with soft substrates.

Surface tension driven aggregation of organic nanowires via lab in a droplet.

Science.gov (United States)

Gu, Jianmin; Yin, Baipeng; Fu, Shaoyan; Feng, Man; Zhang, Ziming; Dong, Haiyun; Gao, Faming; Zhao, Yong Sheng

2018-06-05

Directing the architecture of complex organic nanostructures is desirable and still remains a challenge in areas of materials science due to their structure-dependent collective optoelectronic properties. Herein, we demonstrate a simple and versatile solution strategy that allows surface tension to drive low-dimensional nanostructures to aggregate into complex structures via a lab in a droplet technique. By selecting a suitable combination of a solvent and an anti-solvent with controllable surface tension difference, the droplets can be automatically cracked into micro-droplets, which provides an aggregation force directed toward the centre of the droplet to drive the low-dimensional building blocks to form the special aggregations during the self-assembly process. This synthetic strategy has been shown to be universal for organic materials, which is beneficial for further optimizing the optoelectronic properties. These results contribute to gaining an insightful understanding on the detailed growth mechanism of complex organic nanostructures and greatly promoting the development of organic nanophotonics.

Recent Advance in Organic Spintronics and Magnetic Field Effect

Science.gov (United States)

Valy Vardeny, Z.

2013-03-01

In this talk several important advances in the field of Organic Spintronics and magnetic field effect (MFE) of organic films and optoelectronic devices that have occurred during the past two years from the Utah group will be surveyed and discussed. (i) Organic Spintronics: We demonstrated spin organic light emitting diode (spin-OLED) using two FM injecting electrodes, where the electroluminescence depends on the mutual orientation of the electrode magnetization directions. This development has opened up research studies into organic spin-valves (OSV) in the space-charge limited current regime. (ii) Magnetic field effect: We demonstrated that the photoinduced absorption spectrum in organic films (where current is not involved) show pronounced MFE. This unravels the underlying mechanism of the MFE in organic devices, to be more in agreement with the field of MFE in Biochemistry. (iii) Spin effects in organic optoelectronic devices: We demonstrated that certain spin 1/2 radical additives to donor-acceptor blends substantially enhance the power conversion efficiency of organic photovoltaic (OPV) solar cells. This effect shows that studies of spin response and MFE in OPV devices are promising. In collaboration with T. Nguyen, E. Ehrenfreund, B. Gautam, Y. Zhang and T. Basel. Supported by the DOE grant 04ER46109 ; NSF Grant # DMR-1104495 and MSF-MRSEC program DMR-1121252 [2,3].

Cooperation Agreement. The text of the Cooperation Agreement between the International Atomic Energy Agency and the ITER International Fusion Energy Organization

International Nuclear Information System (INIS)

2009-01-01

The text of the Cooperation Agreement between the International Atomic Energy Agency and the ITER International Fusion Energy Organization is reproduced herein for the information of all Members. The Agreement entered into force on 13 October 2008 pursuant to Article 8

Cooperation Agreement. The Text of the Cooperation Agreement between the International Atomic Energy Agency and the ITER International Fusion Energy Organization

International Nuclear Information System (INIS)

2009-01-01

The text of the Cooperation Agreement between the International Atomic Energy Agency and the ITER International Fusion Energy Organization is reproduced herein for the information of all Members. The Agreement entered into force on 13 October 2008 pursuant to Article 8

A whole-process progressive training mode to foster optoelectronic students' innovative practical ability

Science.gov (United States)

Zhong, Hairong; Xu, Wei; Hu, Haojun; Duan, Chengfang

2017-08-01

This article analyzes the features of fostering optoelectronic students' innovative practical ability based on the knowledge structure of optoelectronic disciplines, which not only reveals the common law of cultivating students' innovative practical ability, but also considers the characteristics of the major: (1) The basic theory is difficult, and the close combination of science and technology is obvious; (2)With the integration of optics, mechanics, electronics and computer, the system technology is comprehensive; (3) It has both leading-edge theory and practical applications, so the benefit of cultivating optoelectronic students is high ; (4) The equipment is precise and the practice is costly. Considering the concept and structural characteristics of innovative and practical ability, and adhering to the idea of running practice through the whole process, we put forward the construction of three-dimensional innovation and practice platform which consists of "Synthetically Teaching Laboratory + Innovation Practice Base + Scientific Research Laboratory + Major Practice Base + Joint Teaching and Training Base", and meanwhile build a whole-process progressive training mode to foster optoelectronic students' innovative practical ability, following the process of "basic experimental skills training - professional experimental skills training - system design - innovative practice - scientific research project training - expanded training - graduation project": (1) To create an in - class practical ability cultivation environment that has distinctive characteristics of the major, with the teaching laboratory as the basic platform; (2) To create an extra-curricular innovation practice activities cultivation environment that is closely linked to the practical application, with the innovation practice base as a platform for improvement; (3) To create an innovation practice training cultivation environment that leads the development of cutting-edge, with the scientific

International co-operation

International Nuclear Information System (INIS)

Klinda, J.; Lieskovska, Z.

1998-01-01

Within the Union Nations (UN) framework, the Slovak Republic participated in following activities on environment protection co-operation: UN European Economic Commission, UN Industrial Development Organization, UN Development Programme, UN Human Habitat Organization, UN Environment Programme, and UN Commission on Sustainable Development. Relevant activities of the Slovak Republic in these co-operations as well as in European Union and OECD activities are reviewed. International conventions and other forms of multilateral co-operation, bilateral co-operation, and international programmes and projects in which the Slovak Republic took participate are presented

Cooperation of Russian and EU technical support organizations

International Nuclear Information System (INIS)

Kuznetsov, M.V.; Kozlov, Vl.V.; Kapralov, E.Yu.

2007-01-01

Since 1992, the fruitful collaboration of the Russian and Western-European technical support organizations (TSOs) is being continued due to the support of the European Commission. There are two main areas of activities. The first one is more of methodological assistance and enhancing RF TSOs capabilities to support Rostekhnadzor decision making process. Experience and knowledge acquired in this area projects increase RF TSOs capabilities regarding a wide spectrum of safety related issues assessment, in particular safety analyses, reactor vessel embrittlement, application of 'leak before break' concept, severe accident and accident management, fire risk evaluation, etc. The second area is focused on licensing related assessments of EC financed on site assistance projects (modernisations). This area projects promote implementation in Russia a licensing process based on a technical dialogue between operator and regulator as well contributes to transfer of Western practice in assessment of NPPs modernization. The improvement of managerial, scientific and technical capabilities of RF TSO experts may be considered as noteworthy and practical result of the TSOs cooperation. The continuation of such modality of RF and EU TSOs cooperation will be a good basis to cope with present and future challenges faced by TSOs in enhancing nuclear safety. (author)

The Shanghai Cooperation Organization: Should the U.S. be Concerned?

Science.gov (United States)

2013-03-01

Cooperation Organization and the Central Asian States, Thesis for Master of Arts in China-U.S. Relations (University of Hawaii at Hilo , December 2007...Clinton reinforced U.S. desires to coordinate with the SCO (among other Asian regional institutions) at a January 2010 conference in Hawaii . 101F102...Hillary Rodham Clinton, Hillary Rodham, “Remarks on Regional Architecture in Asia: Principles and Priorities,” Hawaii , Department of State, January 12

Wonder of nanotechnology quantum optoelectronic devices and applications

CERN Document Server

Razeghi, Manijeh; von Klitzing, Klaus

2013-01-01

When you look closely, Nature is nanotechnology at its finest. From a single cell, a factory all by itself, to complex systems, such as the nervous system or the human eye, each is composed of specialized nanostructures that exist to perform a specific function. This same beauty can be mirrored when we interact with the tiny physical world that is the realm of quantum mechanics.The Wonder of Nanotechnology: Quantum Optoelectronic Devices and Applications, edited by Manijeh Razeghi, Leo Esaki, and Klaus von Klitzing focuses on the application of nanotechnology to modern semiconductor optoelectr

Joint effects of asymmetric payoff and reciprocity mechanisms on collective cooperation in water sharing interactions: a game theoretic perspective.

Directory of Open Access Journals (Sweden)

Cho Nam Ng

Full Text Available Common-pool resource (CPR dilemmas distinguish themselves from general public good problems by encompassing both social and physical features. This paper examines how a physical mechanism, namely asymmetric payoff; and a social mechanism, reciprocity; simultaneously affect collective cooperation in theoretical water sharing interactions. We present an iterative N-person game theoretic model to investigate the joint effects of these two mechanisms in a linear fully connected river system under three information assumptions. From a simple evolutionary perspective, this paper quantitatively addresses the conditions for Nash Equilibrium in which collective cooperation might be established. The results suggest that direct reciprocity increases every actor's motivation to contribute to the collective good of the river system. Meanwhile, various upstream and downstream actors manifest individual disparities as a result of the direct reciprocity and asymmetric payoff mechanisms. More specifically, the downstream actors are less willing to cooperate unless there is a high probability that long-term interactions are ensured; however, a greater level of asymmetries is likely to increase upstream actors' incentives to cooperate even though the interactions could quickly end. The upstream actors also display weak sensitivity to an increase in the total number of actors, which generally results in a reduction in the other actors' motivation for cooperation. It is also shown that the indirect reciprocity mechanism relaxes the overall conditions for cooperative Nash Equilibrium.

Cooperative motion of intrinsic and actuated semiflexible swimmers

NARCIS (Netherlands)

Llopis, I.; Pagonabarraga, I.; Lagomarsino, M.C.; Lowe, C.P.

2013-01-01

We examine the phenomenon of hydrodynamic-induced cooperativity for pairs of flagellated micro-organism swimmers, of which spermatozoa cells are an example. We consider semiflexible swimmers, where inextensible filaments are driven by an internal intrinsic force and torque-free mechanism (intrinsic

Optoelectronic properties of CC2TA towards a good TADF material

Science.gov (United States)

Mishra, Ashok Kumar

2018-05-01

2,4-bis{f3-(9H-carbazol-9-yl)-9H-carbazol-9-yl}-6-phenyl-1,3,5-triazine (CC2TA) is a triazine derivatives in which the acceptor phenyltriazine unit is used as the central skeleton and donor bicarbazole units are bonded to both ends of the skeleton. Molecular orbital calculations exhibit that the HOMO and LUMO are locally allocated chiefly in the bicarbazole and phenyltriazine units, respectively. There are a class of organic molecules and polymers which exhibit semiconductor behavior because of nearly free conjugate π-electrons. Hopping of these electrons in molecules forms different excited singlet and triplet states named as excitons. Some of these organic molecules can be set to emit photons by triplet-singlet excitonic transition via a process called Thermally Activated Delayed Fluorescence (TADF) which is exploited for designing the Organic Light Emitting diode (OLED.) CC2TA is one of these reported noble metal-free TADF molecules which offers unique opto electronic properties arising from the reverse intersystem crossing between the lowest singlet (S) and triplet (T) excited states. Its ability to harvest triplet excitons for fluorescence through facilitated reverse intersystem crossing (T→S) could directly impact their properties and performances, which is attractive for a wide variety of low-cost optoelectronic device. In the present study, the CC2TA compounds have been taken up for the investigation of various optoelectronic properties including the thermally activated delayed fluorescence (TADF) by using the Koopmans Method and Density Functional Theory. The present study discusses the utility of the CC2TA organic semiconductor as a suitable TADF material essential for developing an efficient Organic Light Emitting Diode (OLED).

Optoelectronic lessons as an interdisciplinary lecture

Science.gov (United States)

Wu, Dan; Wu, Maocheng; Gu, Jihua

2017-08-01

It is noticed that more and more students in college are passionately curious about the optoelectronic technology, since optoelectronic technology has advanced extremely quickly during the last five years and its applications could be found in a lot of domains. The students who are interested in this area may have different educational backgrounds and their majors cover science, engineering, literature and social science, etc. Our course "History of the Optoelectronic Technology" is set up as an interdisciplinary lecture of the "liberal education" at our university, and is available for all students with different academic backgrounds from any departments of our university. The main purpose of the course is to show the interesting and colorful historical aspects of the development of this technology, so that the students from different departments could absorb the academic nourishment they wanted. There are little complex derivations of physical formulas through the whole lecture, but there are still some difficulties about the lecture which is discussed in this paper.

Inertia in Cooperative Remodeling

OpenAIRE

Nilsson, Jerker

1997-01-01

Which organization model is appropriate for a cooperative enterprise depends on the prerequisites in its business environment. When conditions are changing, the firm must adapt itself. The entry of Sweden, Finland, and Austria into the European Union led to radical changes for agricultural cooperation, especially for Swedish cooperatives since agricultural policy was not allowed a transitional period. After two years, Swedish cooperatives have still not adapted their organization model despit...

Collective punishment is more effective than collective reward for promoting cooperation

Science.gov (United States)

Gao, Lei; Wang, Zhen; Pansini, Riccardo; Li, Yao-Tang; Wang, Rui-Wu

2015-12-01

Collective punishment and reward are usually regarded as two potential mechanisms to explain the evolution of cooperation. Both scenarios, however, seem problematic to understand cooperative behavior, because they can raise the second-order free-rider problem and many organisms are not able to discriminate less cooperating individuals. Even though they have been proved to increase cooperation, there has been a debate about which one being more effective. To address this issue, we resort to the N-player evolutionary snowdrift game (NESG), where a collective punishment/reward mechanism is added by allowing some players to display punishment/reward towards all remaining players. By means of numerous simulations and analyses, we find that collective punishment is more effective in promoting cooperation for a relatively high initial frequency of cooperation or for a relatively small group. When the intensity of punishment exceeds a certain threshold, a stable state of full cooperation emerges for both small and large groups. In contrast, such state does not appear for large groups playing a NESG with reward mechanism. In the case of mutualistic interactions, finally, our results show the new payoff with collective punishment/reward can lead to the coexistence of cooperators and defectors when discrimination between these two is not possible.

Studies on the mechanism of functional cooperativity between progesterone and estrogen receptors.

Science.gov (United States)

Bradshaw, M S; Tsai, S Y; Leng, X H; Dobson, A D; Conneely, O M; O'Malley, B W; Tsai, M J

1991-09-05

Steroid response elements (SREs) cooperate with many different cis-acting elements including NF-1 sites, CACCC boxes, and other SREs to induce target gene expression (Schule, R., Muller, M., Otsuka-Murakami, H., and Renkawitz, R. (1988) Nature 332, 87-90; Strahle, U., Schmid, W., and Schutz, G. (1988) EMBO J. 7, 3389-3395). Induction of gene expression can be additive or synergistic with respect to the level of activation by either transactivators. Two mechanisms have been proposed for how synergism occurs: 1) cooperative binding of transcriptional activators to DNA or 2) simultaneous interaction of individually bound activators with a common target protein. We have shown previously that cooperative binding of receptors is important for synergism between two progesterone response elements (PREs). Here we showed that an estrogen response element (ERE) and a PRE can also functionally cooperate and this synergism between an ERE and a PRE is not contributed by cooperative DNA binding. Furthermore, we have demonstrated that the activation domains of the progesterone receptor (PR) (C1Act) are required for synergism between two PREs and sufficient for confirming cooperative binding. However these two activation domains of PR are not sufficient for synergism between an ERE and a PRE. Additional regions within the NH2-terminal and COOH-terminal domains are also required for synergistic interaction between two heterologous SREs.

Co-operation agreement between the European Organization for Nuclear Research (CERN) and the Government of People's Republic of Bangladesh concerning Education, Scientific and Technical Co-operation in High-Energy Physics

CERN Document Server

2014-01-01

Co-operation agreement between the European Organization for Nuclear Research (CERN) and the Government of People's Republic of Bangladesh concerning Education, Scientific and Technical Co-operation in High-Energy Physics

Cooperation Agreement between the European Organization for Nuclear Research (CERN) and The Qatar Foundation for Education, Science and Community Development concerning Scientific and Technical Co-operation in High Energy Physics

CERN Document Server

2016-01-01

Cooperation Agreement between the European Organization for Nuclear Research (CERN) and The Qatar Foundation for Education, Science and Community Development concerning Scientific and Technical Co-operation in High Energy Physics

Cooperation Agreement. The Text of the Cooperation Agreement between the International Atomic Energy Agency and the ITER International Fusion Energy Organization

International Nuclear Information System (INIS)

2009-01-01

The text of the Cooperation Agreement between the International Atomic Energy Agency and the ITER International Fusion Energy Organization is reproduced herein for the information of all Members. The Agreement entered into force on 13 October 2008 pursuant to Article 8 [fr

Cooperation Agreement. The Text of the Cooperation Agreement between the International Atomic Energy Agency and the ITER International Fusion Energy Organization

International Nuclear Information System (INIS)

2009-01-01

The text of the Cooperation Agreement between the International Atomic Energy Agency and the ITER International Fusion Energy Organization is reproduced herein for the information of all Members. The Agreement entered into force on 13 October 2008 pursuant to Article 8 [es

Stereoscopic construction and practice of optoelectronic technology textbook

Science.gov (United States)

Zhou, Zigang; Zhang, Jinlong; Wang, Huili; Yang, Yongjia; Han, Yanling

2017-08-01

It is a professional degree course textbook for the Nation-class Specialty—Optoelectronic Information Science and Engineering, and it is also an engineering practice textbook for the cultivation of photoelectric excellent engineers. The book seeks to comprehensively introduce the theoretical and applied basis of optoelectronic technology, and it's closely linked to the current development of optoelectronic industry frontier and made up of following core contents, including the laser source, the light's transmission, modulation, detection, imaging and display. At the same time, it also embodies the features of the source of laser, the transmission of the waveguide, the electronic means and the optical processing methods.

International cooperation for operating safety

International Nuclear Information System (INIS)

Dupuis, M.C.

1989-03-01

The international-cooperation organization in nuclear safety domain is discussed. The nuclear energy Direction Committee is helped by the Security Committee for Nuclear Power Plants in the cooperation between security organizations of member countries and in the safety and nuclear activity regulations. The importance of the cooperation between experts in human being and engine problems is underlined. The applied methods, exchange activities and activity analysis, and the cooperation of the Nuclear Energy Agency and international organizations is analysed [fr

Active Learning and Cooperative Learning in the Organic Chemistry Lecture Class

Science.gov (United States)

Paulson, Donald R.

1999-08-01

Faculty in the physical sciences are one of the academic groups least receptive to the use of active learning strategies and cooperative learning in their classrooms. This is particularly so in traditional lecture classes. It is the objective of this paper to show how effective these techniques can be in improving student performance in classes. The use of active learning strategies and cooperative learning groups in my organic chemistry lecture classes has increased the overall pass rate in my classes by an astounding 20-30% over the traditional lecture mode. This has been accomplished without any reduction in "standards". The actual methods employed are presented as well as a discussion of how I came to radically change the way I teach my classes.

The Cooperative Organization And Rural Passenger Transportation: An Approach to Community Development.

Science.gov (United States)

Stommes, Eileen S.

The need for passenger transportation is widely recognized by rural communities. Shrinking federal funding has led many communities and human service agencies to experiment with innovative approaches to provide transportation services. One such approach is the use of cooperative organizations to provide needed services. A study conducted by the…

The Texts of the Agency's Co-operation Agreements with Regional Intergovernmental Organizations

International Nuclear Information System (INIS)

1961-01-01

The texts of the Agency's agreements for co-operation with the regional inter-governmental organizations listed below, together with the respective protocols authenticating them, are reproduced in this document in the order in which the agreements entered into force, for the information of all Members of the Agency

The Texts of the Agency's Co-operation Agreements with Regional Intergovernmental Organizations

Energy Technology Data Exchange (ETDEWEB)

NONE

1961-02-07

The texts of the Agency's agreements for co-operation with the regional inter-governmental organizations listed below, together with the respective protocols authenticating them, are reproduced in this document in the order in which the agreements entered into force, for the information of all Members of the Agency.

The Texts of the Agency's Co-operation Agreements with Regional Intergovernmental Organizations

International Nuclear Information System (INIS)

1961-01-01

The texts of the Agency's agreements for co-operation with the regional inter-governmental organizations listed below, together with the respective protocols authenticating them, are reproduced in this document in the order in which the agreements entered into force, for the information of all Members of the Agency [es

Perspectives in optoelectronics

National Research Council Canada - National Science Library

Jha, Sudhanshu S

1995-01-01

..., optoelectronics is playing a major role in both applied as well as basic sciences. In years to come, i t is destined to change the face of information technology and robotics, involving optical sensing and control, information storage, signal and image processing, communications, and computing. Because of the possibility of using large bandwidths availa...

Terahertz optoelectronics in graphene

International Nuclear Information System (INIS)

Otsuji, Taiichi

2016-01-01

Graphene has attracted considerable attention due to its extraordinary carrier transport, optoelectronic, and plasmonic properties originated from its gapless and linear energy spectra enabling various functionalities with extremely high quantum efficiencies that could never be obtained in any existing materials. This paper reviews recent advances in graphene optoelectronics particularly focused on the physics and device functionalities in the terahertz (THz) electromagnetic spectral range. Optical response of graphene is characterized by its optical conductivity and nonequilibrium carrier energy relaxation dynamics, enabling amplification of THz radiation when it is optically or electrically pumped. Current-injection THz lasing has been realized very recently. Graphene plasmon polaritons can greatly enhance the THz light and graphene matter interaction, enabling giant enhancement in detector responsivity as well as amplifier/laser gain. Graphene-based van der Waals heterostructures could give more interesting and energy-efficient functionalities. (author)

Insulating materials for optoelectronics

International Nuclear Information System (INIS)

Agullo-Lopez, F.

1990-01-01

Optoelectronics is an interdisciplinary field. Basic functions of an optoelectronic system include the generator of the optical signal, its transmission and handling and, finally, its detection, storage and display. A large variety of semiconductor and insulating materials are used or are being considered to perform those functions. The authors focus on insulating materials, mostly oxides. For signal generation, tunable solid state lasers, either vibronic or those based oon colour centres are briefly described, and their main operating parameters summarized. Reference is made to some developments on fiber and waveguide lasers. Relevant physical features of the silica fibres used for low-loss, long-band, optical transmission are reviewed, as well as present efforts to further reduce attenuation in the mid-infrared range. Particular attention is paid to photorefractive materials (LiNbO 3 , BGO, BSO, etc.), which are being investigated

Effect of annealing over optoelectronic properties of graphene based transparent electrodes

Energy Technology Data Exchange (ETDEWEB)

Yadav, Shriniwas, E-mail: sniwas89@gmail.com; Kaur, Inderpreet, E-mail: inderpreety@yahoo.co.in [Academy of Scientific and Innovative Research- Central Scientific Instruments Organisation (AcSIR-CSIO), Sector-30C, Chandigarh (India); Council of Scientific and Industrial Research- Central Scientific Instruments Organisation (CSIR-CSIO), Sector-30C, Chandigarh (India)

2016-04-13

Graphene, an atom–thick two dimensional graphitic material have led various fundamental breakthroughs in the field of science and technology. Due to their exceptional optical, physical and electrical properties, graphene based transparent electrodes have shown several applications in organic light emitting diodes, solar cells and thin film transistors. Here, we are presenting effect of annealing over optoelectronic properties of graphene based transparent electrodes. Graphene based transparent electrodes have been prepared by wet chemical approach over glass substrates. After fabrication, these electrodes tested for optical transmittance in visible region. Sheet resistance was measured using four probe method. Effect of thermal annealing at 200 °C was studied over optical and electrical performance of these electrodes. Optoelectronic performance was judged from ratio of direct current conductivity to optical conductivity (σ{sub dc}/σ{sub opt}) as a figure of merit for transparent conductors. The fabricated electrodes display good optical and electrical properties. Such electrodes can be alternatives for doped metal oxide based transparent electrodes.

Effect of annealing over optoelectronic properties of graphene based transparent electrodes

Science.gov (United States)

Yadav, Shriniwas; Kaur, Inderpreet

2016-04-01

Graphene, an atom-thick two dimensional graphitic material have led various fundamental breakthroughs in the field of science and technology. Due to their exceptional optical, physical and electrical properties, graphene based transparent electrodes have shown several applications in organic light emitting diodes, solar cells and thin film transistors. Here, we are presenting effect of annealing over optoelectronic properties of graphene based transparent electrodes. Graphene based transparent electrodes have been prepared by wet chemical approach over glass substrates. After fabrication, these electrodes tested for optical transmittance in visible region. Sheet resistance was measured using four probe method. Effect of thermal annealing at 200 °C was studied over optical and electrical performance of these electrodes. Optoelectronic performance was judged from ratio of direct current conductivity to optical conductivity (σdc/σopt) as a figure of merit for transparent conductors. The fabricated electrodes display good optical and electrical properties. Such electrodes can be alternatives for doped metal oxide based transparent electrodes.

Design of a dual-axis optoelectronic level for precision angle measurements

International Nuclear Information System (INIS)

Fan, Kuang-Chao; Wang, Tsung-Han; Lin, Sheng-Yi; Liu, Yen-Chih

2011-01-01

The accuracy of machine tools is mainly determined by angular errors during linear motion according to the well-known Abbe principle. Precision angle measurement is important to precision machines. This paper presents the theory and experiments of a new dual-axis optoelectronic level with low cost and high precision. The system adopts a commercial DVD pickup head as the angle sensor in association with the double-layer pendulum mechanism for two-axis swings, respectively. In data processing with a microprocessor, the measured angles of both axes can be displayed on an LCD or exported to an external PC. Calibrated by a triple-beam laser angular interferometer, the error of the dual-axis optoelectronic level is better than ±0.7 arcsec in the measuring range of ±30 arcsec, and the settling time is within 0.5 s. Experiments show the applicability to the inspection of precision machines

State-of-the-art photodetectors for optoelectronic integration at telecommunication wavelength

Directory of Open Access Journals (Sweden)

Eng Png Ching

2015-01-01

Full Text Available Photodetectors hold a critical position in optoelectronic integrated circuits, and they convert light into electricity. Over the past decades, high-performance photodetectors (PDs have been aggressively pursued to enable high-speed, large-bandwidth, and low-noise communication applications. Various material systems have been explored and different structures designed to improve photodetection capability as well as compatibility with CMOS circuits. In this paper, we review state-of-theart photodetection technologies in the telecommunications spectrum based on different material systems, including traditional semiconductors such as InGaAs, Si, Ge and HgCdTe, as well as recently developed systems such as low-dimensional materials (e.g. graphene, carbon nanotube, etc. and noble metal plasmons. The corresponding material properties, fundamental mechanisms, fabrication, theoretical modelling and performance of the typical PDs are presented, including the emerging directions and perspectives of the PDs for optoelectronic integration applications are discussed.

Thermally evaporated mechanically hard tin oxide thin films for opto-electronic apllications

Energy Technology Data Exchange (ETDEWEB)

Tripathy, Sumanta K.; Rajeswari, V. P. [Centre for Nano Science and Technology, GVP College of Engineering (Autonomous), Visakhapatnam- 530048 (India)

2014-01-28

Tungsten doped tin oxide (WTO) and Molybdenum doped tin oxide (MoTO) thin film were deposited on corn glass by thermal evaporation method. The films were annealed at 350°C for one hour. Structural analysis using Xray diffraction data shows both the films are polycrystalline in nature with monoclinic structure of tin oxide, Sn{sub 3}O{sub 4}, corresponding to JCPDS card number 01-078-6064. SEM photograph showed that both the films have spherical grains with size in the range of 20–30 nm. Compositional analysis was carried out using EDS which reveals the presence of Sn, O and the dopant Mo/W only thereby indicating the absence of any secondary phase in the films. The films are found to contain nearly 6 wt% of Mo, 8 wt% of W as dopants respectively. The transmission pattern for both the films in the spectral range 200 – 2000 nm shows that W doping gives a transparency of nearly 80% from 380 nm onwards while Mo doping has less transparency of 39% at 380nm. Film hardness measurement using Triboscope shows a film hardness of about 9–10 GPa for both the films. It indicates that W or M doping in tin oxide provides the films the added advantage of withstanding the mechanical wear and tear due to environmental fluctuations By optimizing the optical and electrical properties, W/Mo doped tin oxide films may be explored as window layers in opto-electronic applications such as solar cells.

Thermally evaporated mechanically hard tin oxide thin films for opto-electronic apllications

International Nuclear Information System (INIS)

Tripathy, Sumanta K.; Rajeswari, V. P.

2014-01-01

Tungsten doped tin oxide (WTO) and Molybdenum doped tin oxide (MoTO) thin film were deposited on corn glass by thermal evaporation method. The films were annealed at 350°C for one hour. Structural analysis using Xray diffraction data shows both the films are polycrystalline in nature with monoclinic structure of tin oxide, Sn 3 O 4 , corresponding to JCPDS card number 01-078-6064. SEM photograph showed that both the films have spherical grains with size in the range of 20–30 nm. Compositional analysis was carried out using EDS which reveals the presence of Sn, O and the dopant Mo/W only thereby indicating the absence of any secondary phase in the films. The films are found to contain nearly 6 wt% of Mo, 8 wt% of W as dopants respectively. The transmission pattern for both the films in the spectral range 200 – 2000 nm shows that W doping gives a transparency of nearly 80% from 380 nm onwards while Mo doping has less transparency of 39% at 380nm. Film hardness measurement using Triboscope shows a film hardness of about 9–10 GPa for both the films. It indicates that W or M doping in tin oxide provides the films the added advantage of withstanding the mechanical wear and tear due to environmental fluctuations By optimizing the optical and electrical properties, W/Mo doped tin oxide films may be explored as window layers in opto-electronic applications such as solar cells

New cooperative mechanisms of low-energy nuclear reactions using super low-energy external field

International Nuclear Information System (INIS)

Gareev, F.A.; Zhidkova, I.E.

2006-01-01

We propose a new mechanism of LENR: cooperative processes in the whole system, nuclei + atoms + condensed matter, can occur at a smaller threshold energies than the corresponding ones on free constituents. The cooperative processes can be induced and enhanced by low-energy external fields. The excess heat is the emission of internal energy and transmutations at LENR are the result of redistribution of inner energy of the whole system. (author)

New Cooperative Mechanisms of Low-Energy Nuclear Reactions Using Super Low-Energy External Field

Science.gov (United States)

Gareev, F. A.; Zhidkova, I. E.

We propose a new mechanism of LENR: cooperative processes in the whole system, nuclei + atoms + condensed matter, can occur at a smaller threshold energies than the corresponding ones on free constituents. The cooperative processes can be induced and enhanced by low-energy external fields. The excess heat is the emission of internal energy and transmutations at LENR are the result of redistribution of inner energy of the whole system.

Temperature-Dependent Electric Field Poling Effects in CH3NH3PbI3 Optoelectronic Devices.

Science.gov (United States)

Zhang, Chuang; Sun, Dali; Liu, Xiaojie; Sheng, Chuan-Xiang; Vardeny, Zeev Valy

2017-04-06

Organo-lead halide perovskites show excellent optoelectronic properties; however, the unexpected inconsistency in forward-backward I-V characteristics remains a problem for fabricating solar panels. Here we have investigated the reasons behind this "hysteresis" by following the changes in photocurrent and photoluminescence under electric field poling in transverse CH 3 NH 3 PbI 3 -based devices from 300 to 10 K. We found that the hysteresis disappears at cryogenic temperatures, indicating the "freeze-out" of the ionic diffusion contribution. When the same device is cooled under continuous poling, the built-in electric field from ion accumulation brings significant photovoltaic effect even at 10 K. From the change of photoluminescence upon polling, we found a second dipole-related mechanism which enhances radiative recombination upon the alignment of the organic cations. The ionic origin of hysteresis was also verified by applying a magnetic field to affect the ion diffusion. These findings reveal the coexistence of ionic and dipole-related mechanisms for the hysteresis in hybrid perovskites.

Visit of H.E. Dr Abdolrahim Gavahi, Secretary General, Economic Cooperation Organization, Islamic Republic of Iran

CERN Multimedia

Patrice Loïez

2001-01-01

Photo 01: L.to r. Prof. Galileo Violini, Head, UNESCO Office, Teheran; Mr Jan van der Boon, CERN Director of Administration; H.E. Dr Abdolrahim Gavahi, Secretary General, Economic Cooperation Organization, Islamic Republic of Iran (signing the Guest Book); Dr John Ellis, CERN Adviser for Non-Member State Relations and Dr Behzad Alipour Tehrany Photo 02: Mr Jan van der Boon, CERN Director of Administration (left) and Dr John Ellis, CERN Adviser for Non-Member State Relations (right) on the occasion of the visit of H.E. Dr Abdolrahim Gavahi, Secretary General, Economic Cooperation Organization, Islamic Republic of Iran.

Transparent Electrodes for Efficient Optoelectronics

KAUST Repository

Morales-Masis, Monica

2017-03-30

With the development of new generations of optoelectronic devices that combine high performance and novel functionalities (e.g., flexibility/bendability, adaptability, semi or full transparency), several classes of transparent electrodes have been developed in recent years. These range from optimized transparent conductive oxides (TCOs), which are historically the most commonly used transparent electrodes, to new electrodes made from nano- and 2D materials (e.g., metal nanowire networks and graphene), and to hybrid electrodes that integrate TCOs or dielectrics with nanowires, metal grids, or ultrathin metal films. Here, the most relevant transparent electrodes developed to date are introduced, their fundamental properties are described, and their materials are classified according to specific application requirements in high efficiency solar cells and flexible organic light-emitting diodes (OLEDs). This information serves as a guideline for selecting and developing appropriate transparent electrodes according to intended application requirements and functionality.

Transparent Electrodes for Efficient Optoelectronics

KAUST Repository

Morales-Masis, Monica; De Wolf, Stefaan; Woods-Robinson, Rachel; Ager, Joel W.; Ballif, Christophe

2017-01-01

With the development of new generations of optoelectronic devices that combine high performance and novel functionalities (e.g., flexibility/bendability, adaptability, semi or full transparency), several classes of transparent electrodes have been developed in recent years. These range from optimized transparent conductive oxides (TCOs), which are historically the most commonly used transparent electrodes, to new electrodes made from nano- and 2D materials (e.g., metal nanowire networks and graphene), and to hybrid electrodes that integrate TCOs or dielectrics with nanowires, metal grids, or ultrathin metal films. Here, the most relevant transparent electrodes developed to date are introduced, their fundamental properties are described, and their materials are classified according to specific application requirements in high efficiency solar cells and flexible organic light-emitting diodes (OLEDs). This information serves as a guideline for selecting and developing appropriate transparent electrodes according to intended application requirements and functionality.

Mid-infrared Semiconductor Optoelectronics

CERN Document Server

Krier, Anthony

2006-01-01

The practical realisation of optoelectronic devices operating in the 2–10 µm (mid-infrared) wavelength range offers potential applications in a variety of areas from environmental gas monitoring around oil rigs and landfill sites to the detection of pharmaceuticals, particularly narcotics. In addition, an atmospheric transmission window exists between 3 µm and 5 µm that enables free-space optical communications, thermal imaging applications and the development of infrared measures for "homeland security". Consequently, the mid-infrared is very attractive for the development of sensitive optical sensor instrumentation. Unfortunately, the nature of the likely applications dictates stringent requirements in terms of laser operation, miniaturisation and cost that are difficult to meet. Many of the necessary improvements are linked to a better ability to fabricate and to understand the optoelectronic properties of suitable high-quality epitaxial materials and device structures. Substantial progress in these m...

Monolithic optoelectronic integrated broadband optical receiver with graphene photodetectors

Directory of Open Access Journals (Sweden)

Cheng Chuantong

2017-07-01

Full Text Available Optical receivers with potentially high operation bandwidth and low cost have received considerable interest due to rapidly growing data traffic and potential Tb/s optical interconnect requirements. Experimental realization of 65 GHz optical signal detection and 262 GHz intrinsic operation speed reveals the significance role of graphene photodetectors (PDs in optical interconnect domains. In this work, a novel complementary metal oxide semiconductor post-backend process has been developed for integrating graphene PDs onto silicon integrated circuit chips. A prototype monolithic optoelectronic integrated optical receiver has been successfully demonstrated for the first time. Moreover, this is a firstly reported broadband optical receiver benefiting from natural broadband light absorption features of graphene material. This work is a perfect exhibition of the concept of monolithic optoelectronic integration and will pave way to monolithically integrated graphene optoelectronic devices with silicon ICs for three-dimensional optoelectronic integrated circuit chips.

Monolithic optoelectronic integrated broadband optical receiver with graphene photodetectors

Science.gov (United States)

Cheng, Chuantong; Huang, Beiju; Mao, Xurui; Zhang, Zanyun; Zhang, Zan; Geng, Zhaoxin; Xue, Ping; Chen, Hongda

2017-07-01

Optical receivers with potentially high operation bandwidth and low cost have received considerable interest due to rapidly growing data traffic and potential Tb/s optical interconnect requirements. Experimental realization of 65 GHz optical signal detection and 262 GHz intrinsic operation speed reveals the significance role of graphene photodetectors (PDs) in optical interconnect domains. In this work, a novel complementary metal oxide semiconductor post-backend process has been developed for integrating graphene PDs onto silicon integrated circuit chips. A prototype monolithic optoelectronic integrated optical receiver has been successfully demonstrated for the first time. Moreover, this is a firstly reported broadband optical receiver benefiting from natural broadband light absorption features of graphene material. This work is a perfect exhibition of the concept of monolithic optoelectronic integration and will pave way to monolithically integrated graphene optoelectronic devices with silicon ICs for three-dimensional optoelectronic integrated circuit chips.

RIR-MAPLE deposition of conjugated polymers and hybrid nanocomposites for application to optoelectronic devices

International Nuclear Information System (INIS)

Stiff-Roberts, Adrienne D.; Pate, Ryan; McCormick, Ryan; Lantz, Kevin R.

2012-01-01

Resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) is a variation of pulsed laser deposition that is useful for organic-based thin films because it reduces material degradation by selective absorption of infrared radiation in the host matrix. A unique emulsion-based RIR-MAPLE approach has been developed that reduces substrate exposure to solvents and provides controlled and repeatable organic thin film deposition. In order to establish emulsion-based RIR-MAPLE as a preferred deposition technique for conjugated polymer or hybrid nanocomposite optoelectronic devices, studies have been conducted to demonstrate the value added by the approach in comparison to traditional solution-based deposition techniques, and this work will be reviewed. The control of hybrid nanocomposite thin film deposition, and the photoconductivity in such materials deposited using emulsion-based RIR-MAPLE, will also be reviewed. The overall result of these studies is the demonstration of emulsion-based RIR-MAPLE as a viable option for the fabrication of conjugated polymer and hybrid nanocomposite optoelectronic devices that could yield improved device performance.

Promoting cooperation by preventing exploitation: The role of network structure

Science.gov (United States)

Utkovski, Zoran; Stojkoski, Viktor; Basnarkov, Lasko; Kocarev, Ljupco

2017-08-01

A growing body of empirical evidence indicates that social and cooperative behavior can be affected by cognitive and neurological factors, suggesting the existence of state-based decision-making mechanisms that may have emerged by evolution. Motivated by these observations, we propose a simple mechanism of anonymous network interactions identified as a form of generalized reciprocity—a concept organized around the premise "help anyone if helped by someone'—and study its dynamics on random graphs. In the presence of such a mechanism, the evolution of cooperation is related to the dynamics of the levels of investments (i.e., probabilities of cooperation) of the individual nodes engaging in interactions. We demonstrate that the propensity for cooperation is determined by a network centrality measure here referred to as neighborhood importance index and discuss relevant implications to natural and artificial systems. To address the robustness of the state-based strategies to an invasion of defectors, we additionally provide an analysis which redefines the results for the case when a fraction of the nodes behave as unconditional defectors.

The Korean Peninsula Energy Development Organization : implications for Northeast Asian regional security co-operation?

International Nuclear Information System (INIS)

Snyder, S.

2000-01-01

This paper identifies opportunities for co-operation on regional development and security in the North Pacific region. The Korean Peninsula Energy Development Organization (KEDO) was created in 1993 during bilateral negotiations between the United States and the Democratic People's Republic of Korea (US-DPRK) over North Korea's alleged nuclear weapons program. The negotiations resulted in an agreement to freeze North Korea's known nuclear weapons program in return for the construction of two proliferation-resistant 100 MWe light water reactors (LWR) in North Korea, and the provision of 500,000 tons of heavy fuel oil per year until the completion of the LWR construction as compensation for lost energy production capacity resulting from the shutting down of North Korea's nuclear reactors. The author described the activities of KEDO and examined its internal dynamics. The unique circumstances that produced the Agreed Framework and KEDO in response to a major international crisis of the nuclear program in the DPRK were also highlighted along with the US-DPRK bilateral agreement and the multilateral institution involving the United States, South Korea, Japan and the European Union. Financial support from Australia and Canada was discussed along with the mechanism for engaging North Korea in regularized interaction and technical cooperation. It was concluded that KEDO's record of successes and failures is mixed. The energy security issue has been identified as an area that could result in conflict among Northeast Asian countries which are increasingly dependent on oil supplies from the Middle East. In response, numerous multilateral financing mechanisms have been developed to promote joint business opportunities that exploit natural gas resources in the Russian Far East to address Japanese, Korean and Chinese energy needs. 35 refs

CuPc/C60 heterojunction thin film optoelectronic devices

International Nuclear Information System (INIS)

Murtaza, Imran; Karimov, Khasan S.; Qazi, Ibrahim

2010-01-01

The optoelectronic properties of heterojunction thin film devices with ITO/CuPc/C 60 /Al structure have been investigated by analyzing their current-voltage characteristics, optical absorption and photocurrent. In this organic photovoltaic device, CuPc acts as an optically active layer, C 60 as an electron-transporting layer and ITO and Al as electrodes. It is observed that, under illumination, excitons are formed, which subsequently drift towards the interface with C 60 , where an internal electric field is present. The excitons that reach the interface are subsequently dissociated into free charge carriers due to the electric field present at the interface. The experimental results show that in this device the total current density is a function of injected carriers at the electrode-organic semiconductor surface, the leakage current through the organic layer and collected photogenerated current that results from the effective dissociation of excitons. (semiconductor devices)

Advanced educational program in optoelectronics for undergraduates and graduates in electronics

Science.gov (United States)

Vladescu, Marian; Schiopu, Paul

2015-02-01

The optoelectronics education included in electronics curricula at Faculty of Electronics, Telecommunications and Information Technology of "Politehnica" University of Bucharest started in early '90s, and evolved constantly since then, trying to address the growing demand of engineers with a complex optoelectronics profile and to meet the increased requirements of microelectronics, optoelectronics, and lately nanotechnologies. Our goal is to provide a high level of theoretical background combined with advanced experimental tools in laboratories, and also with simulation platforms. That's why we propose an advanced educational program in optoelectronics for both grades of our study program, bachelor and master.

Issues related to cooperative implementation mechanisms

International Nuclear Information System (INIS)

1998-01-01

This note by the secretariat seeks to focus discussions on some key issues regarding the design and functioning of the three new mechanisms, such as issues concerning mandates, cross-cutting as well as issues concerning individual mechanisms. The note addresses each mechanism separately in view of different origins, approaches, participants and possible applications. Reference is, however, made to similarities among the mechanisms, in particular where coordination of work on methodological and institutional issues and inter-institutional collaboration are concerned. The note suggests, in its concluding part, elements of a work programme up to and, to some extent, beyond COP 4. It draws upon the views submitted by Parties (document FCCC/SB/1998/MISC.1), contains reflections by the secretariat and builds on its consultations with other organizations having activities, under way or planned, that could contribute to the design or operation of the mechanisms. (au)

Modification of the optoelectronic properties of two-dimensional MoS2 crystals by ultraviolet-ozone treatment

Science.gov (United States)

Yang, Hae In; Park, Seonyoung; Choi, Woong

2018-06-01

We report the modification of the optoelectronic properties of mechanically-exfoliated single layer MoS2 by ultraviolet-ozone exposure. Photoluminescence emission of pristine MoS2 monotonically decreased and eventually quenched as ultraviolet-ozone exposure time increased from 0 to 10 min. The reduction of photoluminescence emission accompanied reduction of Raman modes, suggesting structural degradation in ultraviolet-ozone exposed MoS2. Analysis with X-ray photoelectron spectroscopy revealed that the formation of Ssbnd O and Mosbnd O bonding increases with ultraviolet-ozone exposure time. Measurement of electrical transport properties of MoS2 in a bottom-gate thin-film transistor configuration suggested the presence of insulating MoO3 after ultraviolet-ozone exposure. These results demonstrate that ultraviolet-ozone exposure can significantly influence the optoelectronic properties of single layer MoS2, providing important implications on the application of MoS2 and other two-dimensional materials into optoelectronic devices.

Features of the piezo-phototronic effect on optoelectronic devices based on wurtzite semiconductor nanowires.

Science.gov (United States)

Yang, Qing; Wu, Yuanpeng; Liu, Ying; Pan, Caofeng; Wang, Zhong Lin

2014-02-21

The piezo-phototronic effect, a three way coupling effect of piezoelectric, semiconductor and photonic properties in non-central symmetric semiconductor materials, utilizing the piezo-potential as a "gate" voltage to tune the charge transport/generation/recombination and modulate the performance of optoelectronic devices, has formed a new field and attracted lots of interest recently. The mechanism was verified in various optoelectronic devices such as light emitting diodes (LEDs), photodetectors and solar cells etc. The fast development and dramatic increasing interest in the piezo-phototronic field not only demonstrate the way the piezo-phototronic effects work, but also indicate the strong need for further research in the physical mechanism and potential applications. Furthermore, it is important to distinguish the contribution of the piezo-phototronic effect from other factors induced by external strain such as piezoresistance, band shifting or contact area change, which also affect the carrier behaviour and device performance. In this perspective, we review our recent progress on piezo-phototronics and especially focus on pointing out the features of piezo-phototronic effect in four aspects: I-V characteristics; c-axis orientation; influence of illumination; and modulation of carrier behaviour. Finally we proposed several criteria for describing the contribution made by the piezo-phototronic effect to the performance of optoelectronic devices. This systematic analysis and comparison will not only help give an in-depth understanding of the piezo-phototronic effect, but also work as guide for the design of devices in related areas.

Reframing cooperation: Challenges in overcoming tensions between professional services and volunteer organizations providing parenting support in immigrant communities

NARCIS (Netherlands)

Ponzoni, E.

2015-01-01

Volunteer organizations can potentially partner with mainstream professional services to provide better parenting support to immigrant parents. This qualitative study of cooperation between professional agencies and volunteer organizations known as migrant volunteer and community organizations

Integrated optoelectronic materials and circuits for optical interconnects

International Nuclear Information System (INIS)

Hutcheson, L.D.

1988-01-01

Conventional interconnect and switching technology is rapidly becoming a critical issue in the realization of systems using high speed silicon and GaAs based technologies. In recent years clock speeds and on-chip density for VLSI/VHSIC technology has made packaging these high speed chips extremely difficult. A strong case can be made for using optical interconnects for on-chip/on-wafer, chip-to-chip and board-to-board high speed communications. GaAs integrated optoelectronic circuits (IOC's) are being developed in a number of laboratories for performing Input/Output functions at all levels. In this paper integrated optoelectronic materials, electronics and optoelectronic devices are presented. IOC's are examined from the standpoint of what it takes to fabricate the devices and what performance can be expected

Nano crystals for Electronic and Optoelectronic Applications

International Nuclear Information System (INIS)

Zhu, T.; Cloutier, S.G.; Ivanov, I; Knappenberger Jr, K.L.; Robel, I.; Zhang, F

2012-01-01

Electronic and optoelectronic devices, from computers and smart cell phones to solar cells, have become a part of our life. Currently, devices with featured circuits of 45 nm in size can be fabricated for commercial use. However, further development based on traditional semiconductor is hindered by the increasing thermal issues and the manufacturing cost. During the last decade, nano crystals have been widely adopted in various electronic and optoelectronic applications. They provide alternative options in terms of ease of processing, low cost, better flexibility, and superior electronic/optoelectronic properties. By taking advantage of solution-processing, self-assembly, and surface engineering, nano crystals could serve as new building blocks for low-cost manufacturing of flexible and large area devices. Tunable electronic structures combined with small exciton binding energy, high luminescence efficiency, and low thermal conductivity make nano crystals extremely attractive for FET, memory device, solar cell, solid-state lighting/display, photodetector, and lasing applications. Efforts to harness the nano crystal quantum tunability have led to the successful demonstration of many prototype devices, raising the public awareness to the wide range of solutions that nano technology can provide for an efficient energy economy. This special issue aims to provide the readers with the latest achievements of nano crystals in electronic and optoelectronic applications, including the synthesis and engineering of nano crystals towards the applications and the corresponding device fabrication, characterization and computer modeling.

Electronic and optoelectronic materials and devices inspired by nature

Science.gov (United States)

Meredith, P.; Bettinger, C. J.; Irimia-Vladu, M.; Mostert, A. B.; Schwenn, P. E.

2013-03-01

Inorganic semiconductors permeate virtually every sphere of modern human existence. Micro-fabricated memory elements, processors, sensors, circuit elements, lasers, displays, detectors, etc are ubiquitous. However, the dawn of the 21st century has brought with it immense new challenges, and indeed opportunities—some of which require a paradigm shift in the way we think about resource use and disposal, which in turn directly impacts our ongoing relationship with inorganic semiconductors such as silicon and gallium arsenide. Furthermore, advances in fields such as nano-medicine and bioelectronics, and the impending revolution of the ‘ubiquitous sensor network’, all require new functional materials which are bio-compatible, cheap, have minimal embedded manufacturing energy plus extremely low power consumption, and are mechanically robust and flexible for integration with tissues, building structures, fabrics and all manner of hosts. In this short review article we summarize current progress in creating materials with such properties. We focus primarily on organic and bio-organic electronic and optoelectronic systems derived from or inspired by nature, and outline the complex charge transport and photo-physics which control their behaviour. We also introduce the concept of electrical devices based upon ion or proton flow (‘ionics and protonics’) and focus particularly on their role as a signal interface with biological systems. Finally, we highlight recent advances in creating working devices, some of which have bio-inspired architectures, and summarize the current issues, challenges and potential solutions. This is a rich new playground for the modern materials physicist.

Quantum dot optoelectronic devices: lasers, photodetectors and solar cells

International Nuclear Information System (INIS)

Wu, Jiang; Chen, Siming; Seeds, Alwyn; Liu, Huiyun

2015-01-01

Nanometre-scale semiconductor devices have been envisioned as next-generation technologies with high integration and functionality. Quantum dots, or the so-called ‘artificial atoms’, exhibit unique properties due to their quantum confinement in all 3D. These unique properties have brought to light the great potential of quantum dots in optoelectronic applications. Numerous efforts worldwide have been devoted to these promising nanomaterials for next-generation optoelectronic devices, such as lasers, photodetectors, amplifiers, and solar cells, with the emphasis on improving performance and functionality. Through the development in optoelectronic devices based on quantum dots over the last two decades, quantum dot devices with exceptional performance surpassing previous devices are evidenced. This review describes recent developments in quantum dot optoelectronic devices over the last few years. The paper will highlight the major progress made in 1.3 μm quantum dot lasers, quantum dot infrared photodetectors, and quantum dot solar cells. (topical review)

OMNI: An optoelectronic multichannel network interface based on hybrid CMOS-SEED technology

Science.gov (United States)

Pinkston, Timothy M.

1996-11-01

This paper presents a hybrid CMOS-SEED multiprocessor network interface smart pixel design that implements a reservation-based channel control protocol for collisionless concurrent access to multiple optical interprocessor communication channels. An asynchronous optical token is used as the arbitration mechanism for reservation control instead of slotted access. This work demonstrates that complex network protocol functions can be implemented using optoelectronic smart pixel technology.

The MOVPE growth mechanism of catalyst-free self-organized GaN columns in H2 and N2 carrier gases

Science.gov (United States)

Wang, Xue; Jahn, Uwe; Ledig, Johannes; Wehmann, Hergo-H.; Mandl, Martin; Straßburg, Martin; Waag, Andreas

2013-12-01

Columnar structures of III-V semiconductors recently attract considerable attention because of their potential applications in novel optoelectronic and electronic devices. In the present study, the mechanisms for the growth of catalyst-free self-organized GaN columns on sapphire substrate by metal organic vapor phase epitaxy have been thoroughly investigated. The growth behaviours are strongly affected by the choice of carrier gas. If pure nitrogen is used, Ga droplets are able to accumulate on the top of columns during growth, and they are converted into a high quality GaN layer during the cool down phase due to nitridation. Hydrogen as the carrier gas can improve the optical quality of the overall GaN columns substantially, and in addition increase the vertical growth rate. In this case, no indication of Ga droplets could be detected. Furthermore, silane doping during the growth promotes the vertical growth in both cases either pure nitrogen or pure hydrogen as the carrier gas.

Integrated Optoelectronic Networks for Application-Driven Multicore Computing

Science.gov (United States)

2017-05-08

AFRL-AFOSR-VA-TR-2017-0102 Integrated Optoelectronic Networks for Application- Driven Multicore Computing Sudeep Pasricha COLORADO STATE UNIVERSITY...AND SUBTITLE Integrated Optoelectronic Networks for Application-Driven Multicore Computing 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA9550-13-1-0110 5c...and supportive materials with innovative architectural designs that integrate these components according to system-wide application needs. 15

Exceptional Optoelectronic Properties of Hydrogenated Bilayer Silicene

Directory of Open Access Journals (Sweden)

Bing Huang

2014-05-01

Full Text Available Silicon is arguably the best electronic material, but it is not a good optoelectronic material. By employing first-principles calculations and the cluster-expansion approach, we discover that hydrogenated bilayer silicene (BS shows promising potential as a new kind of optoelectronic material. Most significantly, hydrogenation converts the intrinsic BS, a strongly indirect semiconductor, into a direct-gap semiconductor with a widely tunable band gap. At low hydrogen concentrations, four ground states of single- and double-sided hydrogenated BS are characterized by dipole-allowed direct (or quasidirect band gaps in the desirable range from 1 to 1.5 eV, suitable for solar applications. At high hydrogen concentrations, three well-ordered double-sided hydrogenated BS structures exhibit direct (or quasidirect band gaps in the color range of red, green, and blue, affording white light-emitting diodes. Our findings open opportunities to search for new silicon-based light-absorption and light-emitting materials for earth-abundant, high-efficiency, optoelectronic applications.

Analysis of optoelectronic strategic planning in Taiwan by artificial intelligence portfolio tool

Science.gov (United States)

Chang, Rang-Seng

1992-05-01

Taiwan ROC has achieved significant advances in the optoelectronic industry with some Taiwan products ranked high in the world market and technology. Six segmentations of optoelectronic were planned. Each one was divided into several strategic items, design artificial intelligent portfolio tool (AIPT) to analyze the optoelectronic strategic planning in Taiwan. The portfolio is designed to provoke strategic thinking intelligently. This computer- generated strategy should be selected and modified by the individual. Some strategies for the development of the Taiwan optoelectronic industry also are discussed in this paper.

Exploration on the training mode of application-oriented talents majoring in optoelectronic information

Science.gov (United States)

Lv, Hao; Liu, Aimei; Zhang, Shengyi; Xiao, Yongjun

2017-08-01

The optoelectronic information major is a strong theoretical and practical specialty. In view of the problems existing in the application-oriented talents training in the optoelectronic information specialty. Five aspects of the talent cultivation plan, the teaching staff, the teaching content, the practical teaching and the scientific research on the training mode of application-oriented talents majoring in optoelectronic information are putted forward. It is beneficial to the specialty construction of optoelectronic information industry which become close to the development of enterprises, and the depth of the integration of school and enterprise service regional economic optoelectronic information high-end skilled personnel base.

Cooperation induces other cooperation: Fruiting bodies promote the evolution of macrocysts in Dictyostelium discoideum.

Science.gov (United States)

Shibasaki, Shota; Shirokawa, Yuka; Shimada, Masakazu

2017-05-21

Biological studies of the evolution of cooperation are challenging because this process is vulnerable to cheating. Many mechanisms, including kin discrimination, spatial structure, or by-products of self-interested behaviors, can explain this evolution. Here we propose that the evolution of cooperation can be induced by other cooperation. To test this idea, we used a model organism Dictyostelium discoideum because it exhibits two cooperative dormant phases, the fruiting body and the macrocyst. In both phases, the same chemoattractant, cyclic AMP (cAMP), is used to collect cells. This common feature led us to hypothesize that the evolution of macrocyst formation would be induced by coexistence with fruiting bodies. Before forming a mathematical model, we confirmed that macrocysts coexisted with fruiting bodies, at least under laboratory conditions. Next, we analyzed our evolutionary game theory-based model to investigate whether coexistence with fruiting bodies would stabilize macrocyst formation. The model suggests that macrocyst formation represents an evolutionarily stable strategy and a global invader strategy under this coexistence, but is unstable if the model ignores the fruiting body formation. This result indicates that the evolution of macrocyst formation and maintenance is attributable to coexistence with fruiting bodies. Therefore, macrocyst evolution can be considered as an example of evolution of cooperation induced by other cooperation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Organic ferroelectric opto-electronic memories

NARCIS (Netherlands)

Asadi, K.; Li, M.; Blom, P.W.M.; Kemerink, M.; Leeuw, D.M. de

2011-01-01

Memory is a prerequisite for many electronic devices. Organic non-volatile memory devices based on ferroelectricity are a promising approach towards the development of a low-cost memory technology based on a simple cross-bar array. In this review article we discuss the latest developments in this

A User Cooperation Stimulating Strategy Based on Cooperative Game Theory in Cooperative Relay Networks

Directory of Open Access Journals (Sweden)

Ping Zhang

2009-01-01

Full Text Available This paper proposes a user cooperation stimulating strategy among rational users. The strategy is based on cooperative game theory and enacted in the context of cooperative relay networks. Using the pricing-based mechanism, the system is modeled initially with two nodes and a Base Station (BS. Within this framework, each node is treated as a rational decision maker. To this end, each node can decide whether to cooperate and how to cooperate. Cooperative game theory assists in providing an optimal system utility and provides fairness among users. Under different cooperative forwarding modes, certain questions are carefully investigated, including “what is each node's best reaction to maximize its utility?” and “what is the optimal reimbursement to encourage cooperation?” Simulation results show that the nodes benefit from the proposed cooperation stimulating strategy in terms of utility and thus justify the fairness between each user.

A User Cooperation Stimulating Strategy Based on Cooperative Game Theory in Cooperative Relay Networks

Directory of Open Access Journals (Sweden)

Jiang Fan

2009-01-01

Full Text Available This paper proposes a user cooperation stimulating strategy among rational users. The strategy is based on cooperative game theory and enacted in the context of cooperative relay networks. Using the pricing-based mechanism, the system is modeled initially with two nodes and a Base Station (BS. Within this framework, each node is treated as a rational decision maker. To this end, each node can decide whether to cooperate and how to cooperate. Cooperative game theory assists in providing an optimal system utility and provides fairness among users. Under different cooperative forwarding modes, certain questions are carefully investigated, including "what is each node's best reaction to maximize its utility?" and "what is the optimal reimbursement to encourage cooperation?" Simulation results show that the nodes benefit from the proposed cooperation stimulating strategy in terms of utility and thus justify the fairness between each user.

76 FR 44592 - Cooperative Agreement With the World Health Organization Department of Food Safety and Zoonoses...

Science.gov (United States)

2011-07-26

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2011-N-0010] Cooperative Agreement With the World Health Organization Department of Food Safety and Zoonoses in Support of... agreement with the World Health Organization. The document published stating that the total funding...

Progress on Crystal Growth of Two-Dimensional Semiconductors for Optoelectronic Applications

Directory of Open Access Journals (Sweden)

Bingqi Sun

2018-06-01

Full Text Available Two-dimensional (2D semiconductors are thought to belong to the most promising candidates for future nanoelectronic applications, due to their unique advantages and capability in continuing the downscaling of complementary metal–oxide–semiconductor (CMOS devices while retaining decent mobility. Recently, optoelectronic devices based on novel synthetic 2D semiconductors have been reported, exhibiting comparable performance to the traditional solid-state devices. This review briefly describes the development of the growth of 2D crystals for applications in optoelectronics, including photodetectors, light-emitting diodes (LEDs, and solar cells. Such atomically thin materials with promising optoelectronic properties are very attractive for future advanced transparent optoelectronics as well as flexible and wearable/portable electronic devices.

Fracton pairing mechanism for unconventional superconductors: Self-assembling organic polymers and copper-oxide compounds

DEFF Research Database (Denmark)

Milovanov, A.V.; Juul Rasmussen, J.

2002-01-01

Self-assembling organic polymers and copper-oxide compounds are two classes of unconventional superconductors, whose challenging behavior does not comply with the traditional picture of Bardeen-Cooper-Schrieffer (BCS) superconductivity in regular crystals. In this paper, we propose a theoretical...... or holes) exchange fracton excitations, quantum oscillations of fractal lattices that mimic the complex microscopic organization of the unconventional superconductors. For the copper oxides, the superconducting transition temperature T-c as predicted by the fracton mechanism is of the order of similar to......150 K. We suggest that the marginal ingredient of the high-temperature superconducting phase is provided by fracton coupled holes that condensate in the conducting copper-oxygen planes owing to the intrinsic field-effect-transistor configuration of the cuprate compounds. For the gate...

Deformable paper origami optoelectronic devices

KAUST Repository

He, Jr-Hau; Lin, Chun-Ho

2017-01-01

Deformable optoelectronic devices are provided, including photodetectors, photodiodes, and photovoltaic cells. The devices can be made on a variety of paper substrates, and can include a plurality of fold segments in the paper substrate creating a

Network Partnership Diplomatic Mechanism: The New Path in Sino-Russian Cooperation - On the Sino-Russian Joint Dominance of BRICS Governance Mechanism

Directory of Open Access Journals (Sweden)

Zhijie Cheng

2014-01-01

Full Text Available 成志杰 王 宛 【内容提要】中俄合作是将来一定时期内国际格局变革与发展的决定性力量。但是，中俄关系存在典型的“二律背反”情结：既借重又怀疑,既合作又防范。处理两国关系，除了原有的双边机制外，中俄还可以通过网状伙伴外交机制进行多边机制下的合作。网状伙伴外交机制主要是指中俄在各个相关多边机制内的互动合作，是双方彼此需要、彼此借重，有效处理双边关系，共同应对国际事务的灵活机制。它具有自身的逻辑。加强和深化中俄合作并不意味着中俄要结盟。网状伙伴外交机制的提出更多是中俄合作的新路径，对于缓解中俄关系中竞争与博弈困境、促进相关国际机制发展等具有重要的意义。金砖国家应该建立金砖国家治理型机制。它需要一个主导性力量中心进行推动。网状伙伴外交机制有利于塑造金砖国家机制的主导性力量中心——中俄联合主导，它是金砖国家治理型机制的内涵之一。中俄联合主导将会在金砖国家机制发展中发挥引领作用。 Sino-Russian cooperation will become an important force in reforming and developing the international system in the near future. However, Sino-Russian relations are complicated since the two countries maintain a guarded attitude towards each other even while cooperating extensively. In addition to furthering bilateral relations, China and Russia can also choose to cooperate through multilateral network mechanisms. This provides opportunities for flexible and strategic cooperation and coordination between the two countries. Strengthening and deepening the Sino-Russian cooperation does not imply forming an actual alliance. The network partnership diplomatic mechanism could play an important role in alleviating competition and mistrust between China and Russia, promoting the development of relevant international

16 CFR 703.3 - Mechanism organization.

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Mechanism organization. 703.3 Section 703.3 Commercial Practices FEDERAL TRADE COMMISSION RULES, REGULATIONS, STATEMENTS AND INTERPRETATIONS UNDER THE... § 703.3 Mechanism organization. (a) The Mechanism shall be funded and competently staffed at a level...

Kazakhstan's Chairmanship of the Organization for Security and Cooperation in Europe: An Assessment

Directory of Open Access Journals (Sweden)

- Shirin Akiner

2011-06-01

Full Text Available Massive international comment and analysis was devoted to the Kazakhstan's Chairmanship in the Organization for Security and Cooperation in Europe (OSCE. No previous candidate for this office received such treatment. Kazakhstan's agenda of aims and objectives included important issues. During the year several steps were taken towards implementing Kazakhstan's agenda.

Integrated optoelectronic oscillator.

Science.gov (United States)

Tang, Jian; Hao, Tengfei; Li, Wei; Domenech, David; Baños, Rocio; Muñoz, Pascual; Zhu, Ninghua; Capmany, José; Li, Ming

2018-04-30

With the rapid development of the modern communication systems, radar and wireless services, microwave signal with high-frequency, high-spectral-purity and frequency tunability as well as microwave generator with light weight, compact size, power-efficient and low cost are increasingly demanded. Integrated microwave photonics (IMWP) is regarded as a prospective way to meet these demands by hybridizing the microwave circuits and the photonics circuits on chip. In this article, we propose and experimentally demonstrate an integrated optoelectronic oscillator (IOEO). All of the devices needed in the optoelectronic oscillation loop circuit are monolithically integrated on chip within size of 5×6cm 2 . By tuning the injection current to 44 mA, the output frequency of the proposed IOEO is located at 7.30 GHz with phase noise value of -91 dBc/Hz@1MHz. When the injection current is increased to 65 mA, the output frequency can be changed to 8.87 GHz with phase noise value of -92 dBc/Hz@1MHz. Both of the oscillation frequency can be slightly tuned within 20 MHz around the center oscillation frequency by tuning the injection current. The method about improving the performance of IOEO is carefully discussed at the end of in this article.

Evolution of Cooperation in Adaptive Social Networks

Science.gov (United States)

Segbroeck, Sven Van; Santos, Francisco C.; Traulsen, Arne; Lenaerts, Tom; Pacheco, Jorge M.

Humans are organized in societies, a phenomenon that would never have been possible without the evolution of cooperative behavior. Several mechanisms that foster this evolution have been unraveled over the years, with population structure as a prominent promoter of cooperation. Modern networks of exchange and cooperation are, however, becoming increasingly volatile, and less and less based on long-term stable structure. Here, we address how this change of paradigm aspects the evolution of cooperation. We discuss analytical and numerical models in which individuals can break social ties and create new ones. Interactions are modeled as two-player dilemmas of cooperation. Once a link between two individuals has formed, the productivity of this link is evaluated. Links can be broken off at different rates. This individual capacity of forming new links or severing inconvenient ones can effectively change the nature of the game. We address random formation of new links and local linking rules as well as different individual capacities to maintain social interactions. We conclude by discussing how adaptive social networks can become an important step towards more realistic models of cultural dynamics.

Parallel optoelectronic trinary signed-digit division

Science.gov (United States)

Alam, Mohammad S.

1999-03-01

The trinary signed-digit (TSD) number system has been found to be very useful for parallel addition and subtraction of any arbitrary length operands in constant time. Using the TSD addition and multiplication modules as the basic building blocks, we develop an efficient algorithm for performing parallel TSD division in constant time. The proposed division technique uses one TSD subtraction and two TSD multiplication steps. An optoelectronic correlator based architecture is suggested for implementation of the proposed TSD division algorithm, which fully exploits the parallelism and high processing speed of optics. An efficient spatial encoding scheme is used to ensure better utilization of space bandwidth product of the spatial light modulators used in the optoelectronic implementation.

Light sensors based on organic phototransistors with absorption-enhancing nanoparticles

DEFF Research Database (Denmark)

Runge Walther, Anders; Linnet, Jes; Albrektsen, Ole

Organic semiconductors (OSCs) exhibit promising electronic and optical properties applicable in photo-sensing devices. Previous studies have found that thiophene-based semiconductors are suitable as the active layer in organic optoelectronic devices such as light-sensing transistors [1]. The abil......Organic semiconductors (OSCs) exhibit promising electronic and optical properties applicable in photo-sensing devices. Previous studies have found that thiophene-based semiconductors are suitable as the active layer in organic optoelectronic devices such as light-sensing transistors [1...

Cooperatives as Entrants

OpenAIRE

Richard J. Sexton; Terri A. Sexton

1987-01-01

A potential shortcoming of game-theoretic models in industrial organization is their failure to consider consumers as players. We introduce a customer coalition --- a cooperative -- as a potential entrant and compare the cooperative entry threat with that posed by the usual for-profit entrant. We identify four fundamental distinctions between cooperative and for-profit entrants and demonstrate that the strategic interplay between a cooperative and an incumbent firm may differ markedly from th...

Barriers and Critical Success Factors for the Implementation of Cooperation Mechanisms

DEFF Research Database (Denmark)

Hansen, Lise-Lotte Pade; Klinge Jacobsen, Henrik

This document reports activities and results of Task 3.1 of the Intelligent Energy Europe supported project RES4Less. This work is the initial analyses and survey of barriers for implementing cooperation mechanisms in the EU countries. This work builds on earlier Intelligent Energy Europe projects...... also shared and enriched by comments from other members of the RES4Less Team during internal meetings of the project....

Off Shore wind energy – Case study of cooperation mechanisms design

DEFF Research Database (Denmark)

Klinge Jacobsen, Henrik; Hansen, Lise-Lotte Pade; Jansen, Jaap

2012-01-01

This document reports activities and results of Task 3.3 of the Intelligent Energy Europe supported project RES4Less. This work is the initial analyses and survey of barriers for implementing cooperation mechanisms in the EU countries. This work builds on earlier Intelligent Energy Europe projects...... also shared and enriched by comments from other members of the RES4Less Team during internal meetings of the project....

78 FR 49757 - Notification of an Expansion to the Cooperative Agreement Award to the World Health Organization

Science.gov (United States)

2013-08-15

... Award to the World Health Organization AGENCY: Biomedical Advanced Research and Development Authority... requires notification to World Health Organization (WHO) as soon as possible, and any confirmed smallpox... Services (HHS). ACTION: Notification of an expansion to the Cooperative Agreement Award to the World Health...

Electronic and optoelectronic materials and devices inspired by nature

International Nuclear Information System (INIS)

Meredith, P; Schwenn, P E; Bettinger, C J; Irimia-Vladu, M; Mostert, A B

2013-01-01

Inorganic semiconductors permeate virtually every sphere of modern human existence. Micro-fabricated memory elements, processors, sensors, circuit elements, lasers, displays, detectors, etc are ubiquitous. However, the dawn of the 21st century has brought with it immense new challenges, and indeed opportunities—some of which require a paradigm shift in the way we think about resource use and disposal, which in turn directly impacts our ongoing relationship with inorganic semiconductors such as silicon and gallium arsenide. Furthermore, advances in fields such as nano-medicine and bioelectronics, and the impending revolution of the ‘ubiquitous sensor network’, all require new functional materials which are bio-compatible, cheap, have minimal embedded manufacturing energy plus extremely low power consumption, and are mechanically robust and flexible for integration with tissues, building structures, fabrics and all manner of hosts. In this short review article we summarize current progress in creating materials with such properties. We focus primarily on organic and bio-organic electronic and optoelectronic systems derived from or inspired by nature, and outline the complex charge transport and photo-physics which control their behaviour. We also introduce the concept of electrical devices based upon ion or proton flow (‘ionics and protonics’) and focus particularly on their role as a signal interface with biological systems. Finally, we highlight recent advances in creating working devices, some of which have bio-inspired architectures, and summarize the current issues, challenges and potential solutions. This is a rich new playground for the modern materials physicist. (review article)

Regional Cooperation Agreement for Asia and the Pacific (RCA). A mechanism for nuclear technology transfer

International Nuclear Information System (INIS)

Bin Muslim, N.

1993-01-01

The paper presents the regional cooperation programs of the IAEA which have as purpose to promote the applications of peaceful uses of atomic energy and to transfer technology to the developing countries. The paper focusses on the (RCA) program for Asia and the Pacific, it is considered the most important mechanism for genuine technology transfer. The annex no 1 lists the full text of the Regional Cooperative Agreement for Research, Development and Training Related to Nuclear Science and Technology, 1987 (13 articles). The annex no.3 lists also the full text of the African Regional Cooperative Agreement for Research, Development and training Related to Nuclear Science and Technology (14 articles). 11 refs., 17 tabs

Cooperative organic mine avoidance path planning

Science.gov (United States)

McCubbin, Christopher B.; Piatko, Christine D.; Peterson, Adam V.; Donnald, Creighton R.; Cohen, David

2005-06-01

The JHU/APL Path Planning team has developed path planning techniques to look for paths that balance the utility and risk associated with different routes through a minefield. Extending on previous years' efforts, we investigated real-world Naval mine avoidance requirements and developed a tactical decision aid (TDA) that satisfies those requirements. APL has developed new mine path planning techniques using graph based and genetic algorithms which quickly produce near-minimum risk paths for complicated fitness functions incorporating risk, path length, ship kinematics, and naval doctrine. The TDA user interface, a Java Swing application that obtains data via Corba interfaces to path planning databases, allows the operator to explore a fusion of historic and in situ mine field data, control the path planner, and display the planning results. To provide a context for the minefield data, the user interface also renders data from the Digital Nautical Chart database, a database created by the National Geospatial-Intelligence Agency containing charts of the world's ports and coastal regions. This TDA has been developed in conjunction with the COMID (Cooperative Organic Mine Defense) system. This paper presents a description of the algorithms, architecture, and application produced.

Mechano-chemical degradation of flexible electrodes for optoelectronic device applications

International Nuclear Information System (INIS)

Bejitual, T.S.; Morris, N.J.; Cronin, S.D.; Cairns, D.R.; Sierros, K.A.

2013-01-01

The electrical, optical, and structural integrity of flexible transparent electrodes is of paramount importance in the design and fabrication of optoelectronic devices such as organic light emitting diodes, liquid crystal displays, touch panels, solar cells, and solid-state lighting. The electrodes may corrode due to acid-containing pressure sensitive adhesives present in the device stacks. In addition, structural failure may occur due to external applied loading. The combined action and further accumulation of both repeated mechanical loading and corrosion can aggravate the loss of functionality of the electrodes. In this study we investigate, using the design of experimental methods, the effects of corrosion, applied mechanical strain, film thickness, and number of bending cycles on the electrical and structural integrity of indium tin oxide (ITO) and carbon nanotube (CNT) films both coated on polyethylene terephthalate (PET) substrates. In situ electrical resistance measurements suggest that fatigue-corrosion is found to be the most critical failure mode for the ITO-based coatings. For example, the change in ITO electrical resistance increase under fatigue-corrosion (1% strain, 150,000 cycles) is 5.8 times higher than that of fatigue mode alone. On the other hand, a minimum change in electrical resistance of the CNT-based electrodes is found when applying the same conditions. - Highlights: • Combined mechano-chemical effects on electrode durability. • CNT-based electrodes outperform ITO counterparts. • Importance of combined fatigue and corrosion action on device reliability

Mechano-chemical degradation of flexible electrodes for optoelectronic device applications

Energy Technology Data Exchange (ETDEWEB)

Bejitual, T.S.; Morris, N.J.; Cronin, S.D.; Cairns, D.R.; Sierros, K.A., E-mail: kostas.sierros@mail.wvu.edu

2013-12-31

The electrical, optical, and structural integrity of flexible transparent electrodes is of paramount importance in the design and fabrication of optoelectronic devices such as organic light emitting diodes, liquid crystal displays, touch panels, solar cells, and solid-state lighting. The electrodes may corrode due to acid-containing pressure sensitive adhesives present in the device stacks. In addition, structural failure may occur due to external applied loading. The combined action and further accumulation of both repeated mechanical loading and corrosion can aggravate the loss of functionality of the electrodes. In this study we investigate, using the design of experimental methods, the effects of corrosion, applied mechanical strain, film thickness, and number of bending cycles on the electrical and structural integrity of indium tin oxide (ITO) and carbon nanotube (CNT) films both coated on polyethylene terephthalate (PET) substrates. In situ electrical resistance measurements suggest that fatigue-corrosion is found to be the most critical failure mode for the ITO-based coatings. For example, the change in ITO electrical resistance increase under fatigue-corrosion (1% strain, 150,000 cycles) is 5.8 times higher than that of fatigue mode alone. On the other hand, a minimum change in electrical resistance of the CNT-based electrodes is found when applying the same conditions. - Highlights: • Combined mechano-chemical effects on electrode durability. • CNT-based electrodes outperform ITO counterparts. • Importance of combined fatigue and corrosion action on device reliability.

Organic High Electron Mobility Transistors Realized by 2D Electron Gas.

Science.gov (United States)

Zhang, Panlong; Wang, Haibo; Yan, Donghang

2017-09-01

A key breakthrough in inorganic modern electronics is the energy-band engineering that plays important role to improve device performance or develop novel functional devices. A typical application is high electron mobility transistors (HEMTs), which utilizes 2D electron gas (2DEG) as transport channel and exhibits very high electron mobility over traditional field-effect transistors (FETs). Recently, organic electronics have made very rapid progress and the band transport model is demonstrated to be more suitable for explaining carrier behavior in high-mobility crystalline organic materials. Therefore, there emerges a chance for applying energy-band engineering in organic semiconductors to tailor their optoelectronic properties. Here, the idea of energy-band engineering is introduced and a novel device configuration is constructed, i.e., using quantum well structures as active layers in organic FETs, to realize organic 2DEG. Under the control of gate voltage, electron carriers are accumulated and confined at quantized energy levels, and show efficient 2D transport. The electron mobility is up to 10 cm 2 V -1 s -1 , and the operation mechanisms of organic HEMTs are also argued. Our results demonstrate the validity of tailoring optoelectronic properties of organic semiconductors by energy-band engineering, offering a promising way for the step forward of organic electronics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The level of influence of trust, commitment, cooperation, and power in the interorganizational relationships of Brazilian credit cooperatives

Directory of Open Access Journals (Sweden)

Denise Maria Martins

Full Text Available Abstract This article aims to analyze the level of influence of trust, commitment, cooperation, and power in the interrelationships of individual credit cooperatives and their central organization in Brazil. The quantitative and descriptive research was developed in unique credit unions linked to the Central Bank of Brazil and the Organization of Brazilian Cooperatives. The data were analyzed using structural equation modeling, with the estimation through partial least squares. The results obtained for the coefficients of determination (R2 of the endogenous latent variables confirmed the assumptions found in the theoretical models of Morgan and Hunt (1994 and Coote, Forrest, and Tam (2003. Statistical significance was also found in the relationships between power and trust, commitment and cooperation, trust and commitment, trust and cooperation, and power and commitment. However, in this study the relationship between power and commitment characterized the significance and was positive between the individual credit cooperatives and their central organization. This is in line with the understanding that power is the solution to resolving conflicts. The research identifies how the constructs of trust, commitment, cooperation, and power show relevance to the alignment of relations between individual credit cooperatives and their central organization.

New Optoelectronic Technology Simplified for Organic Light Emitting Diode (OLED

Directory of Open Access Journals (Sweden)

Andre F. S. Guedes

2014-06-01

Full Text Available The development of Organic Light Emitting Diode (OLED, using an optically transparent substrate material and organic semiconductor materials, has been widely utilized by the electronic industry when producing new technological products. The OLED are the base Poly (3,4-ethylenedioxythiophene, PEDOT, and Polyaniline, PANI, were deposited in Indium Tin Oxide, ITO, and characterized by UV-Visible Spectroscopy (UV-Vis, Optical Parameters (OP and Scanning Electron Microscopy (SEM. In addition, the thin film obtained by the deposition of PANI, prepared in perchloric acid solution, was identified through PANI-X1. The result obtained by UV-Vis has demonstrated that the Quartz/ITO/PEDOT/PANI-X1 layer does not have displacement of absorption for wavelengths greaters after spin-coating and electrodeposition. Thus, the spectral irradiance of the OLED informed the irradiance of 100 W/m2, and this result, compared with the standard Light Emitting Diode (LED, has indicated that the OLED has higher irradiance. After 1000 hours of electrical OLED tests, the appearance of nanoparticles visible for images by SEM, to the migration process of organic semiconductor materials, was present, then. Still, similar to the phenomenon of electromigration observed in connections and interconnections of microelectronic devices, the results have revealed a new mechanism of migration, which raises the passage of electric current in OLED.

Research on the application of optoelectronics to nuclear power plants

International Nuclear Information System (INIS)

Shirosaki, Hidekazu; Mitsuda, Hiromichi; Kurata, Toshikazu; Soramoto, Seiki; Maekawa, Tatsuyuki.

1995-01-01

Optoelectronics, which is based on technologies such as laser diodes and optical fibers, is approaching the realm of practical application in the fields of optical fiber communications and compact disks etc,. In addition, laser enrichment, a type of uranium enrichment technique used in the nuclear field, can also be regarded as a product of optoelectronics. Application of optoelectronics in a wide range of fields is likely to continue in the future, and research is being conducted on coherent optical communication, optical integrated circuits, optical computers and other subjects in hopes of attaining practical application of these technologies in the future. On the other hand, digital control equipment and other related devices have been installed and data transfer using optical fibers has been implemented on a partial basis at nuclear power plants, and optoelectronics is anticipated to be applied on an even broader scale in the future, thereby creating the potential for improving plant reliability. In this research, we conducted an investigative study of technologies relating to optoelectronics, and proposed a remote monitoring system for manually operated valves that employs optical switches. Moreover, we conducted theoretical verification tests on the proposed system and carried out a feasibility study relating to application to nuclear power plants. As a result, the proposed system was found to be effective, and confirmed to have the potential of realization as a valve switching monitoring system. (author)

Applications of confocal laser scanning microscopy in research into organic semiconductor thin films

DEFF Research Database (Denmark)

Schiek, Manuela; Balzer, Frank

2014-01-01

At the center of opto-electronic devices are thin layers of organic semiconductors, which need to be sandwiched between planar electrodes. With the growing demand for opto-electronic devices now and in the future, new electrode materials are needed to meet the requirements of organic semiconductors...

Industrial Buyer-Supplier Cooperation

DEFF Research Database (Denmark)

Olsen, Rasmus Friis

The dissertation considers industrial buyer-supplier cooperation from a systems and management perspective. The purpose is to discuss and elaborate on the buying company’s choice of cooperation strategy (governance mechanism). It is stated that no single governance mechanism will be the best in all...

Meeting report on the ASM Conference on Mechanisms of Interbacterial Cooperation and Competition.

Science.gov (United States)

Lories, Bram; Parijs, Ilse; Foster, Kevin R; Steenackers, Hans P

2017-08-14

The ASM Conference on Mechanisms of Interbacterial Cooperation and Competition was held in Washington DC, from 1 to 4 March 2017. The conference provided an international forum for sociomicrobiologists from different disciplines to present and discuss new findings. The meeting covered a wide range of topics, spanning molecular mechanisms, ecology, evolution, computation and manipulation of interbacterial interactions, and encompassed social communities in medicine, the natural environment, and industry. This report summarizes the presentations and emerging themes. Copyright © 2017 American Society for Microbiology.

Solution growth of single crystal methylammonium lead halide perovskite nanostructures for optoelectronic and photovoltaic applications.

Science.gov (United States)

Fu, Yongping; Meng, Fei; Rowley, Matthew B; Thompson, Blaise J; Shearer, Melinda J; Ma, Dewei; Hamers, Robert J; Wright, John C; Jin, Song

2015-05-06

Understanding crystal growth and improving material quality is important for improving semiconductors for electronic, optoelectronic, and photovoltaic applications. Amidst the surging interest in solar cells based on hybrid organic-inorganic lead halide perovskites and the exciting progress in device performance, improved understanding and better control of the crystal growth of these perovskites could further boost their optoelectronic and photovoltaic performance. Here, we report new insights on the crystal growth of the perovskite materials, especially crystalline nanostructures. Specifically, single crystal nanowires, nanorods, and nanoplates of methylammonium lead halide perovskites (CH3NH3PbI3 and CH3NH3PbBr3) are successfully grown via a dissolution-recrystallization pathway in a solution synthesis from lead iodide (or lead acetate) films coated on substrates. These single crystal nanostructures display strong room-temperature photoluminescence and long carrier lifetime. We also report that a solid-liquid interfacial conversion reaction can create a highly crystalline, nanostructured MAPbI3 film with micrometer grain size and high surface coverage that enables photovoltaic devices with a power conversion efficiency of 10.6%. These results suggest that single-crystal perovskite nanostructures provide improved photophysical properties that are important for fundamental studies and future applications in nanoscale optoelectronic and photonic devices.

Optoelectronic interconnects for 3D wafer stacks

Science.gov (United States)

Ludwig, David; Carson, John C.; Lome, Louis S.

1996-01-01

Wafer and chip stacking are envisioned as means of providing increased processing power within the small confines of a three-dimensional structure. Optoelectronic devices can play an important role in these dense 3-D processing electronic packages in two ways. In pure electronic processing, optoelectronics can provide a method for increasing the number of input/output communication channels within the layers of the 3-D chip stack. Non-free space communication links allow the density of highly parallel input/output ports to increase dramatically over typical edge bus connections. In hybrid processors, where electronics and optics play a role in defining the computational algorithm, free space communication links are typically utilized for, among other reasons, the increased network link complexity which can be achieved. Free space optical interconnections provide bandwidths and interconnection complexity unobtainable in pure electrical interconnections. Stacked 3-D architectures can provide the electronics real estate and structure to deal with the increased bandwidth and global information provided by free space optical communications. This paper will provide definitions and examples of 3-D stacked architectures in optoelectronics processors. The benefits and issues of these technologies will be discussed.

International cooperation during radiological emergencies. NRC program guidance for the provision of technical advice to foreign counterpart organizations

International Nuclear Information System (INIS)

Senseney, R.

1986-04-01

This report defines the scope, application, and limits of the technical cooperation the Nuclear Regulatory Commission (NRC) would provide, upon request, to a foreign regulatory agency in a nuclear emergency. It outlines the basis for such cooperation, offers a model written agreement, and describes recent cases of NRC assistance. It also identifies non-NRC sources of emergency advisory assistance available to foreign organizations

Amorphous electron-accepting materials for organic optoelectronics

NARCIS (Netherlands)

Ganesan, P.

2007-01-01

The importance of organic materials for use in electronic devices such as OLEDs, OFETs and photovoltaic cells has increased significantly over the past decade. Organic materials have been attractive candidates for such electronic devices because of their compatibility with high-throughput,

Seeing smells: development of an optoelectronic nose

Directory of Open Access Journals (Sweden)

Kenneth S. Suslick

2007-06-01

Full Text Available The development of an array of chemically-responsive dyes on a porous membrane and in its use as a general sensor for odors and volatile organic compounds (VOCs is reviewed. These colorimetric sensor arrays (CSA act as an "optoelectronic nose" by using an array of multiple dyes whose color changes are based on the full range of intermolecular interactions. The CSA is digitally imaged before and after exposure and the resulting difference map provides a digital fingerprint for any VOC or mixture of odorants. The result is an enormous increase in discriminatory power among odorants compared to prior electronic nose technologies. For the detection of biologically important analytes, including amines, carboxylic acids, and thiols, high sensitivities (ppbv have been demonstrated. The array is essentially non-responsive to changes in humidity due to the hydrophobicity of the dyes and membrane.

Optoelectronic switch matrix as a look-up table for residue arithmetic.

Science.gov (United States)

Macdonald, R I

1987-10-01

The use of optoelectronic matrix switches to perform look-up table functions in residue arithmetic processors is proposed. In this application, switchable detector arrays give the advantage of a greatly reduced requirement for optical sources by comparison with previous optoelectronic residue processors.

PREFACE: 2nd International School and Conference Saint-Petersburg OPEN on Optoelectronics, Photonics, Engineering and Nanostructures (SPbOPEN2015)

Science.gov (United States)

2015-11-01

The 2nd International School and Conference ''Saint Petersburg OPEN 2015'' on Optoelectronics, Photonics, Engineering and Nanostructures was held on April 6 - 8, 2015 at St. Petersburg Academic University. The School and Conference included a series of invited talks given by leading professors with the aim to introduce young scientists with actual problems and major advances in physics and technology. The keynote speakers were Mikhail V. Maximov (Ioffe Physico-Technical Institute RAS, Russia) Vladimir G. Dubrovskii (St. Petersburg Academic University and St. Petersburg State University, Russia) Anton Yu. Egorov (JSC Connector Optics, Russia) Victor V. Luchinin (St. Petersburg State Electrotechnical University, Russia) Vladislav E. Bugrov (St. Petersburg University of Internet Technologies, Mechanics and Optics, Russia) Vitali A. Schukin (VI Systems, Germany) Yuri P. Svirko (University of Eastern Finland, Finland) During the poster session all undergraduate and graduate students attending the conference presented their works. A sufficiently large number of participants, with more than 170 student attendees from all over the world, allowed the Conference to provide a fertile ground for fruitful discussions between the young scientists as well as to become a perfect platform for valuable discussions between student authors and highly experienced scientists. The best student papers, which were selected by the Program Committee and by the invited speakers basing on the theses and their poster presentation, were awarded with diplomas of the conference - see the photos. This year ''Saint Petersburg OPEN 2015'' is organized by St. Petersburg Academic University in cooperation with Peter the Great St. Petersburg Polytechnic University. The School and Conference is supported by Russian Science Foundation, SPIE (The International Society for Optics and Photonics), OSA (The Optical Society) and by Skolkovo Foundation. It is a continuation of the annual schools and seminars for

Global Organization of Innovation and Cooperability in Brazilian Multinationals

Directory of Open Access Journals (Sweden)

Priscila Rezende da Costa

2017-04-01

Full Text Available Understanding the dissipation of innovations is necessary to develop them, as a company on its own does not have all the capabilities that it needs. On the contrary, they are increasingly spread over internal and external contexts, and are not developed in isolation. Most of the time, they depend on interactive, innovative processes in a global context. The aim of this study is to evaluate how the global organizational structure of innovation affects the dynamic capability of cooperation (cooperability in Brazilian multinationals (BMNs. To achieve this goal, we conducted a survey of BMNs, and a final sample of 60 companies answered a structured questionnaire. We performed statistical tests such as Factor Analysis, Cronbach's Alpha, Multiple Regression and Hierarchical Cluster, and cross-analysis of quantitative results that enabled us to create a Cooperability Model, that is, a model of local, international and global development for a dynamic capability of cooperation in BMNs. The results show that technological strengths of foreign subsidiaries and the reverse transfer of their capabilities to the parent company and technology partners affect the dynamics of cooperation in BMNs (inputs and results of cooperability. Furthermore, we detected an inverse relationship between the autonomy of foreign subsidiaries and the dynamic of cooperation in BMNs.

How mutation alters the evolutionary dynamics of cooperation on networks

Science.gov (United States)

Ichinose, Genki; Satotani, Yoshiki; Sayama, Hiroki

2018-05-01

Cooperation is ubiquitous at every level of living organisms. It is known that spatial (network) structure is a viable mechanism for cooperation to evolve. A recently proposed numerical metric, average gradient of selection (AGoS), a useful tool for interpreting and visualizing evolutionary dynamics on networks, allows simulation results to be visualized on a one-dimensional phase space. However, stochastic mutation of strategies was not considered in the analysis of AGoS. Here we extend AGoS so that it can analyze the evolution of cooperation where mutation may alter strategies of individuals on networks. We show that our extended AGoS correctly visualizes the final states of cooperation with mutation in the individual-based simulations. Our analyses revealed that mutation always has a negative effect on the evolution of cooperation regardless of the payoff functions, fraction of cooperators, and network structures. Moreover, we found that scale-free networks are the most vulnerable to mutation and thus the dynamics of cooperation are altered from bistability to coexistence on those networks, undergoing an imperfect pitchfork bifurcation.

International co-operation

International Nuclear Information System (INIS)

1997-01-01

In 1996, Nuclear Regulatory Authority of the Slovak Republic (NRA SR) ensured the Slovak Republic (SR) obligations with relation to the international agreements and with the SR membership in the IAEA.International co-operation has been ensured on the basis of the bilateral international agreements. With the Ministry of Foreign Affairs co-operation, the SR fulfilled its financial obligations to this organization in due time and in the full scope. Representing Central and Eastern Europe interest in the Board of Governors, the SR participation in the highest executive in the highest executive authority was finished in 1996.The Board of Governors Vice-chairman position was executed by NRA SR Chairman. 5 national and 6 regional technical co-operation and assistance projects were realized in 1996. 12 organizations participated in these projects and accordingly 104 experts took part in training programmes, scientific visits or as the mission members abroad. Besides, Slovak experts participated at work of technical advisory and consultation groups with the significant assistance. In the framework of IAEA co-operation, the SR was visited by 11 expert missions formed by 28 experts from 19 countries including IAEA. Slovak organizations, namely institutes of the Academy of Sciences, Slovak research centres and universities participated in IAEA scientific and research activities through NRA SR. 15 scientific contracts in total were approved and realized and these contracts are utilized as supplementary financing of the own scientific and research projects. Other international co-operation and regional co-operation activities of the NRA SR in 1996 are reviewed

The construction of bilingual teaching of optoelectronic technology

Science.gov (United States)

Zhang, Yang; Zhao, Enming; Yang, Fan; Li, Qingbo; Zhu, Zheng; Li, Cheng; Sun, Peng

2017-08-01

This paper combines the characteristics of optoelectronic technology with that of bilingual teaching. The course pays attention to integrating theory with practice, and cultivating learners' ability. Reform and exploration have been done in the fields of teaching materials, teaching content, teaching methods, etc. The concrete content mainly includes five parts: selecting teaching materials, establishing teaching syllabus, choosing suitable teaching method, making multimedia courseware and improving the test system, which can arouse students' interest in their study and their autonomous learning ability to provide beneficial references for improving the quality of talents of optoelectronic bilingual courses.

Temperature-Induced Lattice Relaxation of Perovskite Crystal Enhances Optoelectronic Properties and Solar Cell Performance

KAUST Repository

Banavoth, Murali

2016-12-14

Hybrid organic-inorganic perovskite crystals have recently become one of the most important classes of photoactive materials in the solar cell and optoelectronic communities. Albeit improvements have focused on state-of-the-art technology including various fabrication methods, device architectures, and surface passivation, progress is yet to be made in understanding the actual operational temperature on the electronic properties and the device performances. Therefore, the substantial effect of temperature on the optoelectronic properties, charge separation, charge recombination dynamics, and photoconversion efficiency are explored. The results clearly demonstrated a significant enhancement in the carrier mobility, photocurrent, charge carrier lifetime, and solar cell performance in the 60 ± 5 °C temperature range. In this temperature range, perovskite crystal exhibits a highly symmetrical relaxed cubic structure with well-aligned domains that are perpendicular to a principal axis, thereby remarkably improving the device operation. This finding provides a new key variable component and paves the way toward using perovskite crystals in highly efficient photovoltaic cells.

Extreme conditions synthesis, processing and characterization of metal-nitrides and alloys of mechanical and optoelectronic importance

International Nuclear Information System (INIS)

Serghiou, G; McGaff, A J; Russell, N; Morniroli, J P; Frost, D J; Odling, N; Boehler, R; Troadec, D; Lathe, C

2010-01-01

High density nitrides and group IV alloys are of growing importance for both ceramic and optoelectronic applications. We present here new data and processes in our ongoing preparation of alkaline earth and transition metal nitrides as well as group IV alloys, here, up to 25 GPa and 2300 K. We employ large volume and laser-heated diamond anvil cell techniques for synthesis, processing tools including focused ion beam, and synchrotron X-ray diffraction, transmission electron microscopy and scanning electron microscopy for characterization.

Research on Contractual Model Selection of Farmers’ Cooperatives——A Case Study of Production and Marketing Cooperative of Sweet Pomegranate in Mengzi,Yunnan

Institute of Scientific and Technical Information of China (English)

2011-01-01

In the perspective of new institutional economics,we regard farmers’ cooperatives as a "contractual set" integrating a series of long-term contractual relations,and transform the selection problem of organization forms into selection problem of contractual model within organization.By the theoretical framework of Transaction Cost Economics,we analyze the formation mechanism and determinant factors of contractual model of different farmers’ cooperatives and conduct case study on Production and Marketing Cooperative of Sweet Pomegranate in Mengzi,Yunnan.The results show that selecting contractual forms of cooperatives is the result of weighing many factors;new organization model or contractual arrangement is complementary to the former system arrangement;the selection of cooperatives model is an important factor impacting cooperation efficiency and stability of organization.One organization model with efficiency not only hinges on the transaction characteristic of organization,but also considers the compatibility with exterior transaction environment.In the process of selecting contractual model,we should conform to objective evolving law,but not be in thrall to a certain given form.

GaAs optoelectronic neuron arrays

Science.gov (United States)

Lin, Steven; Grot, Annette; Luo, Jiafu; Psaltis, Demetri

1993-01-01

A simple optoelectronic circuit integrated monolithically in GaAs to implement sigmoidal neuron responses is presented. The circuit integrates a light-emitting diode with one or two transistors and one or two photodetectors. The design considerations for building arrays with densities of up to 10,000/sq cm are discussed.

A University-Industry Cooperation Model for Small and Medium Enterprises: The Case of Chengdu KEDA Optoelectronic Technology Ltd.

Science.gov (United States)

Peng, Shanzhong; Ferreira, Fernando A. F.; Zheng, He

2017-01-01

In this study, we develop a firm-dominated incremental cooperation model. Following the critical review of current literature and various cooperation models, we identified a number of strengths and shortcomings that form the basis for our framework. The objective of our theoretical model is to contribute to overcome the existing gap within…

Advances in graphene-based optoelectronics, plasmonics and photonics

International Nuclear Information System (INIS)

Nguyen, Bich Ha; Nguyen, Van Hieu

2016-01-01

Since the early works on graphene it has been remarked that graphene is a marvelous electronic material. Soon after its discovery, graphene was efficiently utilized in the fabrication of optoelectronic, plasmonic and photonic devices, including graphene-based Schottky junction solar cells. The present work is a review of the progress in the experimental research on graphene-based optoelectronics, plasmonics and photonics, with the emphasis on recent advances. The main graphene-based optoelectronic devices presented in this review are photodetectors and modulators. In the area of graphene-based plasmonics, a review of the plasmonic nanostructures enhancing or tuning graphene-light interaction, as well as of graphene plasmons is presented. In the area of graphene-based photonics, we report progress on fabrication of different types of graphene quantum dots as well as functionalized graphene and graphene oxide, the research on the photoluminescence and fluorescence of graphene nanostructures as well as on the energy exchange between graphene and semiconductor quantum dots. In particular, the promising achievements of research on graphene-based Schottky junction solar cells is presented. (review)

Cooperation in carbon source degradation shapes spatial self-organization of microbial consortia on hydrated surfaces.

Science.gov (United States)

Tecon, Robin; Or, Dani

2017-03-06

Mounting evidence suggests that natural microbial communities exhibit a high level of spatial organization at the micrometric scale that facilitate ecological interactions and support biogeochemical cycles. Microbial patterns are difficult to study definitively in natural environments due to complex biodiversity, observability and variable physicochemical factors. Here, we examine how trophic dependencies give rise to self-organized spatial patterns of a well-defined bacterial consortium grown on hydrated surfaces. The model consortium consisted of two Pseudomonas putida mutant strains that can fully degrade the aromatic hydrocarbon toluene. We demonstrated that obligate cooperation in toluene degradation (cooperative mutualism) favored convergence of 1:1 partner ratio and strong intermixing at the microscale (10-100 μm). In contrast, competition for benzoate, a compound degraded independently by both strains, led to distinct segregation patterns. Emergence of a persistent spatial pattern has been predicted for surface attached microbial activity in liquid films that mediate diffusive exchanges while permitting limited cell movement (colony expansion). This study of a simple microbial consortium offers mechanistic glimpses into the rules governing the assembly and functioning of complex sessile communities, and points to general principles of spatial organization with potential applications for natural and engineered microbial systems.

Optoelectronic device with nanoparticle embedded hole injection/transport layer

Science.gov (United States)

Wang, Qingwu [Chelmsford, MA; Li, Wenguang [Andover, MA; Jiang, Hua [Methuen, MA

2012-01-03

An optoelectronic device is disclosed that can function as an emitter of optical radiation, such as a light-emitting diode (LED), or as a photovoltaic (PV) device that can be used to convert optical radiation into electrical current, such as a photovoltaic solar cell. The optoelectronic device comprises an anode, a hole injection/transport layer, an active layer, and a cathode, where the hole injection/transport layer includes transparent conductive nanoparticles in a hole transport material.

Practical opto-electronics an illustrated guide for the laboratory

CERN Document Server

Protopopov, Vladimir

2014-01-01

This book explains how to create opto-electronic systems in a most efficient way, avoiding typical mistakes. It covers light detection techniques, imaging, interferometry, spectroscopy, modulation-demodulation, heterodyning, beam steering, and many other topics common to laboratory applications. The focus is made on self-explanatory figures rather than on words. The book guides the reader through the entire process of creating problem-specific opto-electronic systems, starting from optical source, through beam transportation optical arrangement, to photodetector and data acquisition system. The relevant basics of beam propagation and computer-based raytracing routines are also explained, and sample codes are listed. the book teaches important know-how and practical tricks that are never disclosed in scientific publications.  The book can become the reader's personal adviser in the world of opto-electronics and navigator in the ocean of the market of optical components and systems. Succinct, well-illustrate...

An Audit Learning Experience: A Pilot Project through Cooperation with a Third Sector Organization

Science.gov (United States)

Tonge, Richard; Willett, Caroline

2012-01-01

This paper is a critical evaluation of a pilot cooperative education project conducted with a charitable organization in the UK. An action research approach was adopted. Final level students who are studying auditing have had the opportunity to apply the knowledge and skills they are developing through their studies to a real-life situation in the…

Optoelectronic devices product assurance guideline for space application

Science.gov (United States)

Bensoussan, A.; Vanzi, M.

2017-11-01

New opportunities are emerging for the implementation of hardware sub-systems based on OptoElectronic Devices (OED) for space application. Since the end of this decade the main players for space systems namely designers and users including Industries, Agencies, Manufacturers and Laboratories are strongly demanding of adequate strategies to qualify and validate new optoelectronics products and sub-systems [1]. The long term space application mission will require to address either inter-satellite link (free space communication, positioning systems, tracking) or intra-satellite connectivity/flexibility/reconfigurability or high volume of data transfer between equipment installed into payload.

Advanced Optoelectronic Components for All-Optical Networks

National Research Council Canada - National Science Library

Shapiro, Jeffrey H

2002-01-01

Under APOSR Grant F49620-96-1-0126, 'Advanced Optoelectronic Components for All-Optical Networks', we have worked to develop key technologies and components to substantially improve the performance...

Massive ordering and alignment of cylindrical micro-objects by photovoltaic optoelectronic tweezers.

Science.gov (United States)

Elvira, Iris; Muñoz-Martínez, Juan F; Barroso, Álvaro; Denz, Cornelia; Ramiro, José B; García-Cabañes, Angel; Agulló-López, Fernando; Carrascosa, Mercedes

2018-01-01

Optical tools for manipulation and trapping of micro- and nano-objects are a fundamental issue for many applications in nano- and biotechnology. This work reports on the use of one such method, known as photovoltaic optoelectronics tweezers, to orientate and organize cylindrical microcrystals, specifically elongated zeolite L, on the surface of Fe-doped LiNbO 3 crystal plates. Patterns of aligned zeolites have been achieved through the forces and torques generated by the bulk photovoltaic effect. The alignment patterns with zeolites parallel or perpendicular to the substrate surface are highly dependent on the features of light distribution and crystal configuration. Moreover, dielectrophoretic chains of zeolites with lengths up to 100 μm have often been observed. The experimental results of zeolite trapping and alignment have been discussed and compared together with theoretical simulations of the evanescent photovoltaic electric field and the dielectrophoretic potential. They demonstrate the remarkable capabilities of the optoelectronic photovoltaic method to orientate and pattern anisotropic microcrystals. The combined action of patterning and alignment offers a unique tool to prepare functional nanostructures with potential applications in a variety of fields such as nonlinear optics or plasmonics.

In situ–Directed Growth of Organic Nanofibers and Nanoflakes: Electrical and Morphological Properties

DEFF Research Database (Denmark)

Oliveira Hansen, Roana Melina de; Madsen, Morten; Kjelstrup-Hansen, Jakob

2010-01-01

Organic nanostructures made from organic molecules such as para-hexaphenylene (p-6P) could form nanoscale components in future electronic and optoelectronic devices. However, the integration of such fragile nanostructures with the necessary interface circuitry such as metal electrodes for electri......Organic nanostructures made from organic molecules such as para-hexaphenylene (p-6P) could form nanoscale components in future electronic and optoelectronic devices. However, the integration of such fragile nanostructures with the necessary interface circuitry such as metal electrodes...... patterned by a combination of optical lithography and electron beam lithography. The dimensions of the gold electrodes strongly influence the morphology of the resulting structures leading to notably different electrical properties. The ability to control such nanofiber or nanoflake growth opens...... the possibility for large-scale optoelectronic device fabrication....

Incipient cognition solves the spatial reciprocity conundrum of cooperation.

Directory of Open Access Journals (Sweden)

Jeromos Vukov

Full Text Available BACKGROUND: From the simplest living organisms to human societies, cooperation among individuals emerges as a paradox difficult to explain and describe mathematically, although very often observed in reality. Evolutionary game theory offers an excellent toolbar to investigate this issue. Spatial structure has been one of the first mechanisms promoting cooperation; however, alone it only opens a narrow window of viability. METHODOLOGY/PRINCIPAL FINDINGS: Here we equip individuals with incipient cognitive abilities, and investigate the evolution of cooperation in a spatial world where retaliation, forgiveness, treason and mutualism may coexist, as individuals engage in Prisoner's Dilemma games. In the model, individuals are able to distinguish their partners and act towards them based on previous interactions. We show how the simplest level of cognition, alone, can lead to the emergence of cooperation. CONCLUSIONS/SIGNIFICANCE: Despite the incipient nature of the individuals' cognitive abilities, cooperation emerges for unprecedented values of the temptation to cheat, being also robust to invasion by cheaters, errors in decision making and inaccuracy of imitation, features akin to many species, including humans.

Materials for optoelectronic devices, OEICs and photonics

International Nuclear Information System (INIS)

Schloetterer, H.; Quillec, M.; Greene, P.D.; Bertolotti, M.

1991-01-01

The aim of the contributors in this volume is to give a current overview on the basic properties of nonlinear optical materials for optoelectronics and integrated optics. They provide a cross-linkage between different materials (III-V, II-VI, Si-Ge, etc.), various sample dimensions (from bulk crystals to quantum dots), and a range of techniques from growth (LPE to MOMBE) and for processing from surface passivation to ion beams. Major growth techniques and materials are discussed, including the sophisticated technologies required to exploit the exciting properties of low dimensional semiconductors. These proceedings will prove an invaluable guide to the current state of optoelectronic materials development, as well as indicating the growth techniques that will be in use around the year 2000

Scalable Sub-micron Patterning of Organic Materials Toward High Density Soft Electronics.

Science.gov (United States)

Kim, Jaekyun; Kim, Myung-Gil; Kim, Jaehyun; Jo, Sangho; Kang, Jingu; Jo, Jeong-Wan; Lee, Woobin; Hwang, Chahwan; Moon, Juhyuk; Yang, Lin; Kim, Yun-Hi; Noh, Yong-Young; Jaung, Jae Yun; Kim, Yong-Hoon; Park, Sung Kyu

2015-09-28

The success of silicon based high density integrated circuits ignited explosive expansion of microelectronics. Although the inorganic semiconductors have shown superior carrier mobilities for conventional high speed switching devices, the emergence of unconventional applications, such as flexible electronics, highly sensitive photosensors, large area sensor array, and tailored optoelectronics, brought intensive research on next generation electronic materials. The rationally designed multifunctional soft electronic materials, organic and carbon-based semiconductors, are demonstrated with low-cost solution process, exceptional mechanical stability, and on-demand optoelectronic properties. Unfortunately, the industrial implementation of the soft electronic materials has been hindered due to lack of scalable fine-patterning methods. In this report, we demonstrated facile general route for high throughput sub-micron patterning of soft materials, using spatially selective deep-ultraviolet irradiation. For organic and carbon-based materials, the highly energetic photons (e.g. deep-ultraviolet rays) enable direct photo-conversion from conducting/semiconducting to insulating state through molecular dissociation and disordering with spatial resolution down to a sub-μm-scale. The successful demonstration of organic semiconductor circuitry promise our result proliferate industrial adoption of soft materials for next generation electronics.

Cooperation, trust and confidence

NARCIS (Netherlands)

Korver, T.; Oeij, P.R.A.; Urze, P.C.G.D.

2007-01-01

Environmental complexity may strain cooperative relationships, both within and beyond organizations, for two reasons. First, when complexity implies uncertainty the predictability of change disappears. Secondly, change may and often will entail different estimates of the cooperating partners on the

Cooperative loading of multisite receptors with lanthanide containers: an approach for organized luminescent metallopolymers.

Science.gov (United States)

Babel, Lucille; Guénée, Laure; Besnard, Céline; Eliseeva, Svetlana V; Petoud, Stéphane; Piguet, Claude

2018-01-14

Metal-containing (bio)organic polymers are materials of continuously increasing importance for applications in energy storage and conversion, drug delivery, shape-memory items, supported catalysts, organic conductors and smart photonic devices. The embodiment of luminescent components provides a revolution in lighting and signaling with the ever-increasing development of polymeric light-emitting devices. Despite the unique properties expected from the introduction of optically and magnetically active lanthanides into organic polymers, the deficient control of the metal loading currently limits their design to empirical and poorly reproducible materials. We show here that the synthetic efforts required for producing soluble multi-site host systems L k are largely overcome by the virtue of reversible thermodynamics for mastering the metal loading with the help of only two parameters: (1) the affinity of the luminescent lanthanide container for a single binding site and (2) the cooperative effect which modulates the successive fixation of metallic units to adjacent sites. When unsymmetrical perfluorobenzene-trifluoroacetylacetonate co-ligands (pbta - ) are selected for balancing the charge of the trivalent lanthanide cations, Ln 3+ , in six-coordinate [Ln(pbta) 3 ] containers, the explored anti-cooperative complexation processes induce nearest-neighbor intermetallic interactions twice as large as thermal energy at room temperature ( RT = 2.5 kJ mol -1 ). These values have no precedent when using standard symmetrical containers and they pave the way for programming metal alternation in luminescent lanthanidopolymers.

Mechanisms for cytoplasmic organization: an overview.

Science.gov (United States)

Pagliaro, L

2000-01-01

One of the basic characteristics of life is the intrinsic organization of cytoplasm, yet we know surprisingly little about the manner in which cytoplasmic macromolecules are arranged. It is clear that cytoplasm is not the homogeneous "soup" it was once envisioned to be, but a comprehensive model for cytoplasmic organization is not available in modern cell biology. The premise of this volume is that phase separation in cytoplasm may play a role in organization at the subcellular level. Other mechanisms for non-membrane-bounded intracellular organization have previously been proposed. Some of these will be reviewed in this chapter. Multiple mechanisms, involving phase separation, specific intracellular targeting, formation of macromolecular complexes, and channeling, all could well contribute to cytoplasmic organization. Temporal and spatial organization, as well as composition, are likely to be important in defining the characteristics of cytoplasm.

Cooperation between territorial communities: theory and practice

Directory of Open Access Journals (Sweden)

П. М. Любченко

2015-05-01

Full Text Available Problem Setting. The paper analyzes the problems in the system of legal regulation of cooperation between communities, highlights the advantages and disadvantages of such cooperation in Ukrainian local government. Analysis of the recent researches and publications. The legal basis for cooperation in the field of local government are provisions of the Constitution and laws of Ukraine, by-laws. The organizational principles of communities cooperation, principles, forms and mechanisms of such cooperation and its promotion, financing and monitoring prescribed by the Law of Ukraine «On cooperation of local communities» 17 June 2014, which provides five possible forms of cooperation. Paper main body. The first form - delegation to one party of cooperation by another parties of cooperation execution of one or few tasks with transferring of appropriate resources - one of the most difficult to implement, therefore in Ukraine it is not yet implemented. The second form – realization of joint projects, involving coordination of activities between parties of cooperation and accumulating them for a certain period resources to joint implementation of appropriate measures - one of the most common. This  form is popular because of its simplicity and versatility. Parties are determining the purpose of the project, terms and conditions of its implementation, a list of activities and conditions for their implementation, financial liabilities, other forms of local governments participation in implementation of the project and mechanism of coordination. The third and fourth forms aimed on the creation and maintenance of communal enterprises, institutions and organizations - joint infrastructure projects by parties of cooperation. This form of cooperation with the prospect of widespread use because it is aimed at ensuring effective use of resources of local communities based on common application available in one of the subjects of cooperation of municipal

Single-photon superradiance and cooperative Lamb shift in an optoelectronic device (Conference Presentation)

Science.gov (United States)

Sirtori, Carlo

2017-02-01

Superradiance is one of the many fascinating phenomena predicted by quantum electrodynamics that have first been experimentally demonstrated in atomic systems and more recently in condensed matter systems like quantum dots, superconducting q-bits, cyclotron transitions and plasma oscillations in quantum wells (QWs). It occurs when a dense collection of N identical two-level emitters are phased via the exchange of photons, giving rise to enhanced light-matter interaction, hence to a faster emission rate. Of great interest is the regime where the ensemble interacts with one photon only and therefore all of the atoms, but one, are in the ground state. In this case the quantum superposition of all possible configurations produces a symmetric state that decays radiatively with a rate N times larger than that of the individual oscillators. This phenomenon, called single photon superradiance, results from the exchange of real photons among the N emitters. Yet, to single photon superradiance is also associated another collective effect that renormalizes the emission frequency, known as cooperative Lamb shift. In this work, we show that single photon superradiance and cooperative Lamb shift can be engineered in a semiconductor device by coupling spatially separated plasma resonances arising from the collective motion of confined electrons in QWs. These resonances hold a giant dipole along the growth direction z and have no mutual Coulomb coupling. They thus behave as a collection of macro-atoms on different positions along the z axis. Our device is therefore a test bench to simulate the low excitation regime of quantum electrodynamics.

The governance of cooperative societies

Directory of Open Access Journals (Sweden)

Yaiza Juanes Sobradillo

2005-12-01

Full Text Available The present work aims to expose the appropriate legislation for cooperative societies to which Article 129 of the Spanish Constitution refers, deepen the analysis of the organs of management and control based on the Spanish and Basque Laws on Cooperatives and the Statute for the European Cooperative Societies.

Tax cooperation among member states of European Union and Directive on administrative cooperation in the field of taxation

Directory of Open Access Journals (Sweden)

Josimovski Aleksandar G.

2013-01-01

Full Text Available Countries have possibility to choose between several alternatives for cooperation in international tax matters at global level. They can decide not to cooperate or provide some form of tax cooperation. Because of harmful tax competition among countries and efforts of international organizations, all countries in the world are oblidged to comply with one of multiple alternatives for tax cooperation. Situation in European Union (hereinafter EU is specific. EU is not country or classic international organization. By the reason of its successful functioning, EU has need for tax cooperation. EU has attempted to harmonise tax policies of member states, but member states did not approve that. Only indirect taxes are harmonized on EU level, direct taxes are harmonized only to the point necessarily for functioning of single market. That is why tax cooperation instruments are so important. Object of this paper are procedures and measures, stipulated by the most important instrument in the field of tax cooperation enacted by institutions of EU, its development and status in international tax law. Regulatives and directives in field of tax cooperation in the EU are 'pioneers' in tax matters. EU instruments provide standards which are subsequently accepted by several international organizations - Organisation for Economic Co-operation and Development (OECD and United Nations (UN. Our purpose is to present positive and negative aspects of tax cooperation in the EU. In time of crisis efficient tax cooperation provides higher revenues for the member states, on the other hand, taxpayers and tax administrations have increased expenses as result of tax cooperation which are not fairly distributed.

The role of civil organizations in monitoring the convention on the prohibition of the use, stockpiling, production and transfer of anti-personnel mines and on their destruction: a proposal for a cooperative compliance mechanism

International Nuclear Information System (INIS)

Wiseberg, LS.

1998-01-01

On December 2, 1997, approximately 100 government representatives will gather in Ottawa, Canada to sign a treaty banning the production, use or stockpiling of landmines. Both the speed with which this treaty was negotiated, and the extent to which it is a product of genuine cooperation between like-minded governments and non-governmental organizations (especially the International Campaign to Ban Landmines) make it a landmark document. Nonetheless, when the Convention on the Prohibition of the Use, Stockpiling, Production and Transfer of Anti-personnel Mines and on their Destruction (hereinafter, the APM Treaty) is reviewed in the context of other arms control agreements, it is clear that the 'compliance mechanism' is extremely soft. There are no sanctions against states who do not live up to the obligations they assume on signing the APM Treaty, although (under Article 8), States Parties may authorize a fact-finding mission to clarify a question regarding alleged non-compliance. This notwithstanding, the primary compliance mechanism is the provision that states voluntarily report once a year on measures they have taken to implement the treaty. (author)

Cooperation under indirect reciprocity and imitative trust.

Science.gov (United States)

Saavedra, Serguei; Smith, David; Reed-Tsochas, Felix

2010-10-27

Indirect reciprocity, a key concept in behavioral experiments and evolutionary game theory, provides a mechanism that allows reciprocal altruism to emerge in a population of self-regarding individuals even when repeated interactions between pairs of actors are unlikely. Recent empirical evidence show that humans typically follow complex assessment strategies involving both reciprocity and social imitation when making cooperative decisions. However, currently, we have no systematic understanding of how imitation, a mechanism that may also generate negative effects via a process of cumulative advantage, affects cooperation when repeated interactions are unlikely or information about a recipient's reputation is unavailable. Here we extend existing evolutionary models, which use an image score for reputation to track how individuals cooperate by contributing resources, by introducing a new imitative-trust score, which tracks whether actors have been the recipients of cooperation in the past. We show that imitative trust can co-exist with indirect reciprocity mechanisms up to a threshold and then cooperation reverses -revealing the elusive nature of cooperation. Moreover, we find that when information about a recipient's reputation is limited, trusting the action of third parties towards her (i.e. imitating) does favor a higher collective cooperation compared to random-trusting and share-alike mechanisms. We believe these results shed new light on the factors favoring social imitation as an adaptive mechanism in populations of cooperating social actors.

Cooperation under indirect reciprocity and imitative trust.

Directory of Open Access Journals (Sweden)

Serguei Saavedra

Full Text Available Indirect reciprocity, a key concept in behavioral experiments and evolutionary game theory, provides a mechanism that allows reciprocal altruism to emerge in a population of self-regarding individuals even when repeated interactions between pairs of actors are unlikely. Recent empirical evidence show that humans typically follow complex assessment strategies involving both reciprocity and social imitation when making cooperative decisions. However, currently, we have no systematic understanding of how imitation, a mechanism that may also generate negative effects via a process of cumulative advantage, affects cooperation when repeated interactions are unlikely or information about a recipient's reputation is unavailable. Here we extend existing evolutionary models, which use an image score for reputation to track how individuals cooperate by contributing resources, by introducing a new imitative-trust score, which tracks whether actors have been the recipients of cooperation in the past. We show that imitative trust can co-exist with indirect reciprocity mechanisms up to a threshold and then cooperation reverses -revealing the elusive nature of cooperation. Moreover, we find that when information about a recipient's reputation is limited, trusting the action of third parties towards her (i.e. imitating does favor a higher collective cooperation compared to random-trusting and share-alike mechanisms. We believe these results shed new light on the factors favoring social imitation as an adaptive mechanism in populations of cooperating social actors.

Progress in the optoelectronic analog signal transfer for high energy particle detectors

International Nuclear Information System (INIS)

Tsang, T.; Radeka, V.

1992-05-01

We report the progress in the development of a radiation hard Optoelectronic analog system to transfer particle detector signals with high accuracy. We will present the motivation of this study, the operating principle of the optoelectronic system, the system noise study, the recent R ampersand D efforts on radiation effect, temperature stability, and the realization of an integrated l x l6 optical modulator. The issue of photon source for driving such a large-scale optoelectronic modulators is a major concern. We will address this problem by examining different possible photon sources and comment on other possible alternative for signal transfer

Increased Optoelectronic Quality and Uniformity of Hydrogenated p-InP Thin Films

KAUST Repository

Wang, Hsin-Ping; Sutter-Fella, Carolin M.; Lobaccaro, Peter; Hettick, Mark; Zheng, Maxwell; Lien, Der-Hsien; Miller, D. Westley; Warren, Charles W.; Roe, Ellis T; Lonergan, Mark C; Guthrey, Harvey L.; Haegel, Nancy M.; Ager, Joel W.; Carraro, Carlo; Maboudian, Roya; He, Jr-Hau; Javey, Ali

2016-01-01

The thin-film vapor-liquid-solid (TF-VLS) growth technique presents a promising route for high quality, scalable and cost-effective InP thin films for optoelectronic devices. Towards this goal, careful optimization of material properties and device performance is of utmost interest. Here, we show that exposure of polycrystalline Zn-doped TF-VLS InP to a hydrogen plasma (in the following referred to as hydrogenation) results in improved optoelectronic quality as well as lateral optoelectronic uniformity. A combination of low temperature photoluminescence and transient photocurrent spectroscopy were used to analyze the energy position and relative density of defect states before and after hydrogenation. Notably, hydrogenation reduces the intra-gap defect density by one order of magnitude. As a metric to monitor lateral optoelectronic uniformity of polycrystalline TF-VLS InP, photoluminescence and electron beam induced current mapping reveal homogenization of the grain versus grain boundary upon hydrogenation. At the device level, we measured more than 260 TF-VLS InP solar cells before and after hydrogenation to verify the improved optoelectronic properties. Hydrogenation increased the average open-circuit voltage (VOC) of individual TF-VLS InP solar cells by up to 130 mV, and reduced the variance in VOC for the analyzed devices.

Increased Optoelectronic Quality and Uniformity of Hydrogenated p-InP Thin Films

KAUST Repository

Wang, Hsin-Ping

2016-06-08

The thin-film vapor-liquid-solid (TF-VLS) growth technique presents a promising route for high quality, scalable and cost-effective InP thin films for optoelectronic devices. Towards this goal, careful optimization of material properties and device performance is of utmost interest. Here, we show that exposure of polycrystalline Zn-doped TF-VLS InP to a hydrogen plasma (in the following referred to as hydrogenation) results in improved optoelectronic quality as well as lateral optoelectronic uniformity. A combination of low temperature photoluminescence and transient photocurrent spectroscopy were used to analyze the energy position and relative density of defect states before and after hydrogenation. Notably, hydrogenation reduces the intra-gap defect density by one order of magnitude. As a metric to monitor lateral optoelectronic uniformity of polycrystalline TF-VLS InP, photoluminescence and electron beam induced current mapping reveal homogenization of the grain versus grain boundary upon hydrogenation. At the device level, we measured more than 260 TF-VLS InP solar cells before and after hydrogenation to verify the improved optoelectronic properties. Hydrogenation increased the average open-circuit voltage (VOC) of individual TF-VLS InP solar cells by up to 130 mV, and reduced the variance in VOC for the analyzed devices.

The Ways of Using Foreign Experience of Intermunicipal Investment Cooperation

Directory of Open Access Journals (Sweden)

Siryk Zenoviy O.

2018-03-01

Full Text Available The content and nature of intermunicipal investment cooperation (IMIC are disclosed in the article. The aim of the article is to study the foreign experience of intermunicipal investment cooperation with a view to further introduction of local self-government into domestic practice. By analyzing and summarizing the scientific works of many scientists, in which the general experience and mechanism of intermunicipal cooperation is considered, the main features of the reasons for the existence and promotion of intermunicipal investment cooperation are revealed. Some foreign practices of the existence of intermunicipal investment cooperation are analyzed. There made a critical analysis regarding the forms of implementation of such cooperation. Features of the mechanism of functioning of various models of such cooperation are revealed. It is substantiated that the intermunicipal investment IMIC is not a fairly common practice and direction of cooperation between territorial communities and their government bodies. The legislation of most of the analyzed countries does not establish clear rules that would administer or regulate IMIC to an extent required by the practice of territorial management and development of territories. It is determined that a large number of forms, models and methods of implementing IMIC, despite even a certain rarity of their application, attests to the most important characteristic feature of it. It is stated that the following forms of IMIC should be considered as the most effective with regard to domestic practice of organization of local self-government and financial flows: establishment of a separate intermunicipal institution (body authorized to manage or regulate the implementation of investment processes and administration of investment processes by concluding an administrative agreement.

Cooperative motion of intrinsic and actuated semiflexible swimmers

Science.gov (United States)

Llopis, I.; Pagonabarraga, I.; Cosentino Lagomarsino, M.; Lowe, C. P.

2013-03-01

We examine the phenomenon of hydrodynamic-induced cooperativity for pairs of flagellated micro-organism swimmers, of which spermatozoa cells are an example. We consider semiflexible swimmers, where inextensible filaments are driven by an internal intrinsic force and torque-free mechanism (intrinsic swimmers). The velocity gain for swimming cooperatively, which depends on both the geometry and the driving, develops as a result of the near-field coupling of bending and hydrodynamic stresses. We identify the regimes where hydrodynamic cooperativity is advantageous and quantify the change in efficiency. When the filaments' axes are parallel, hydrodynamic interaction induces a directional instability that causes semiflexible swimmers that profit from swimming together to move apart from each other. Biologically, this implies that flagella need to select different synchronized collective states and to compensate for directional instabilities (e.g., by binding) in order to profit from swimming together. By analyzing the cooperative motion of pairs of externally actuated filaments, we assess the impact that stress distribution along the filaments has on their collective displacements.

Research and development of photovoltaic power system. Study of carrier dynamics in a-Si from optical and optoelectronic properties; Taiyoko hatsuden system no kenky kaihatsu. Amorphous silicon no koden tokusei to sono carrier dynamics no kogakuteki kenkyu

Energy Technology Data Exchange (ETDEWEB)

Hamakawa, K [Osaka University, Osaka (Japan). Faculty of Engineering Science

1994-12-01

This paper reports the result obtained during fiscal 1994 on research on an optical study of optoelectronic properties of amorphous silicon and its carrier dynamics. Studies have been performed on elucidation of the optoelectronic conversion mechanism in an a-Si film p-i-n junction system and the relationship of the mechanism with the optoelectronic properties. In the studies, optically induced defect level distribution was evaluated by using the modulated optical current spectroscopy, and confirmation was made on model forecast and qualitative agreement, such as large increase in neutral defect levels in association with beam irradiation. In research on elucidation of a film forming mechanism for a-Si based alloys, and material property control, a high-sensitivity reflective infrared spectroscopy was used to observe mechanisms such as treatments and processes given in device fabrication. In research on optical and optoelectronic properties of an s-Si alloy thin film by using the modulated spectroscopy, a new evaluation technology dealing with amorphous semiconductors was developed. The technology separately evaluates carrier migration factors of electrons and holes by combining polarization angle dependence of electro-absorption signals with hole migration measurements. 4 figs.

The good governance and management  of cooperative societies under cooperative values: a didactic review

Directory of Open Access Journals (Sweden)

José Eduardo Souza de Miranda

2005-12-01

Full Text Available Regarding the administrative management of cooperative enterprises, the various cooperative laws establish the need to organize a social-democratic structure formed by all members of society.

High bandgap III-V alloys for high efficiency optoelectronics

Energy Technology Data Exchange (ETDEWEB)

Alberi, Kirstin; Mascarenhas, Angelo; Wanlass, Mark

2017-01-10

High bandgap alloys for high efficiency optoelectronics are disclosed. An exemplary optoelectronic device may include a substrate, at least one Al.sub.1-xIn.sub.xP layer, and a step-grade buffer between the substrate and at least one Al.sub.1-xIn.sub.xP layer. The buffer may begin with a layer that is substantially lattice matched to GaAs, and may then incrementally increase the lattice constant in each sequential layer until a predetermined lattice constant of Al.sub.1-xIn.sub.xP is reached.

High efficiency optoelectronic terahertz sources

Science.gov (United States)

Lampin, Jean-François; Peytavit, Emilien; Akalin, Tahsin; Ducournau, G.; Hindle, Francis; Mouret, Gael

2010-08-01

We have developed a new generation of optoelectronic large bandwidth terahertz sources based on TEM horn antennas monolithically integrated with several types of photodetectors: low-temperature grown GaAs (LTG-GaAs) planar photoconductors, vertically integrated LTG-GaAs photoconductors on silicon substrate and uni-travelling-carrier photodiodes. Results of pulsed (time-domain) and photomixing (CW, frequency domain) experiments are presented.

Preparation, characterization and optoelectronic properties of nanodiamonds doped zinc oxide nanomaterials by a ball milling technique

Science.gov (United States)

Ullah, Hameed; Sohail, Muhammad; Malik, Uzma; Ali, Naveed; Bangash, Masroor Ahmad; Nawaz, Mohsan

2016-07-01

Zinc oxide (ZnO) is one of the very important metal oxides (MOs) for applications in optoelectronic devices which work in the blue and UV regions. However, to meet the challenges of obtaining ZnO nanomaterials suitable for practical applications, various modifications in physico-chemical properties are highly desirable. One of the ways adopted for altering the properties is to synthesize composite(s) of ZnO with various reinforcements. Here we report on the tuning of optoelectronic properties of ZnO upon doping by nanodiamonds (NDs) using the ball milling technique. A varying weight percent (wt.%) of NDs were ball milled for 2 h with ZnO nanoparticles prepared by a simple precipitation method. The effects of different parameters, the calcination temperature of ZnO, wt.% of NDs and mechanical milling upon the optoelectronic properties of the resulting ZnO-NDs nanocomposites have been investigated. The ZnO-NDs nanocomposites were characterized by IR spectroscopy, powder x-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX). The UV-vis spectroscopy revealed the alteration in the bandgap energy (Eg ) of ZnO as a function of the calcination temperature of ZnO, changing the concentration of NDs, and mechanical milling of the resulting nanocomposites. The photoluminescence (PL) spectroscopy showed a decrease in the deep level emission (DLE) peaks and an increase in near-band-edge transition peaks as a result of the increasing concentration of NDs. The decrease in DLE and increase in band to band transition peaks were due to the strong interaction between the NDs and the Zn+; consequently, the Zn+ concentration decreased on the interstitial sites.

FY 1998 annual report on the research and development of non-linear, opto-electronic materials; 1998 nendo hisenkei hikari denshi zairyo no kenkyu kaihatsu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

The final assessment of researches on non-linear, opto-electronic materials was conducted in FY 1988. These researches are evaluated as the world-level basic researches, high in potential of giving ripple effects on various areas. The R and D themes are organic, low-molecular-weight materials; technology for orientation-controlled crystal growth; conjugated polymer films; microcrystallite-doped glasses using vapor deposition and stuffing method; glass composite materials using sol-gel method and ultra-low melting point glass; nanoparticle-dispersed glasses using super-cooling technology; materials dispersed in organic compounds; organic superlattice formation; three-dimensionally superstructured materials; and comprehensive surveys and researches. The researches and surveys on the common basic techniques were recommissioned to Universities of Tokyo, Keio Gijuku, Nagoya, Tohoku and Hokkaido. These themes are analytical methods for non-linear optical characteristics; morphology-controlled crystal growth of nonlinear-optical organic materials and fundamental studies on all-optical devices; large enhancement of optical nonlinearity and its mechanism in nanocrystals embedded in matrices; improvement of organic materials for high performance; and ultrafast nonlinear optical processes and their application for controlling ultrafast optical pulses. (NEDO)

Mechanical Properties of Organic Semiconductors for Stretchable, Highly Flexible, and Mechanically Robust Electronics.

Science.gov (United States)

Root, Samuel E; Savagatrup, Suchol; Printz, Adam D; Rodriquez, Daniel; Lipomi, Darren J

2017-05-10

Mechanical deformability underpins many of the advantages of organic semiconductors. The mechanical properties of these materials are, however, diverse, and the molecular characteristics that permit charge transport can render the materials stiff and brittle. This review is a comprehensive description of the molecular and morphological parameters that govern the mechanical properties of organic semiconductors. Particular attention is paid to ways in which mechanical deformability and electronic performance can coexist. The review begins with a discussion of flexible and stretchable devices of all types, and in particular the unique characteristics of organic semiconductors. It then discusses the mechanical properties most relevant to deformable devices. In particular, it describes how low modulus, good adhesion, and absolute extensibility prior to fracture enable robust performance, along with mechanical "imperceptibility" if worn on the skin. A description of techniques of metrology precedes a discussion of the mechanical properties of three classes of organic semiconductors: π-conjugated polymers, small molecules, and composites. The discussion of each class of materials focuses on molecular structure and how this structure (and postdeposition processing) influences the solid-state packing structure and thus the mechanical properties. The review concludes with applications of organic semiconductor devices in which every component is intrinsically stretchable or highly flexible.

The Texts of the Agency's Co-operation Agreements with Regional Intergovernmental Organizations; Texte des Accords de Cooperation Conclus entre L'Agence et des Organisations Intergouvernementales Regionales

Energy Technology Data Exchange (ETDEWEB)

NONE

1961-02-07

The texts of the Agency's agreements for co-operation with the regional inter-governmental organizations listed below, together with the respective protocols authenticating them, are reproduced in this document in the order in which the agreements entered into force, for the information of all Members of the Agency [French] Le present document reproduit le texte des accords de cooperation que l'Agence a conclus avec les organisations intergouvernementales regionales enumerees ci-apres, ainsi que celui des protocoles validant lesdits accords. Le texte de ces instruments, classes dans l'ordre chronologique de leur entree en vigueur, est communique, pour information, a tous les Membres de l'Agence.

Extreme Radiation Hardness and Space Qualification of AlGaN Optoelectronic Devices

International Nuclear Information System (INIS)

Sun, Ke-Xun; MacNeil, Lawrence; Balakrishnan, Kathik; Hultgren, Eric; Goebel, John; Bilenko, Yuri; Yang, Jinwei; Sun, Wenhong; Shatalov, Max; Hu, Xuhong; Gaska, Remis

2010-01-01

Unprecedented radiation hardness and environment robustness are required in the new generation of high energy density physics (HEDP) experiments and deep space exploration. National Ignition Facility (NIF) break-even shots will have a neutron yield of 10 15 or higher. The Europa Jupiter System Mission (EJSM) mission instruments will be irradiated with a total fluence of 10 12 protons/cm 2 during the space journey. In addition, large temperature variations and mechanical shocks are expected in these applications under extreme conditions. Hefty radiation and thermal shields are required for Si and GaAs based electronics and optoelectronics devices. However, for direct illumination and imaging applications, shielding is not a viable option. It is an urgent task to search for new semiconductor technologies and to develop radiation hard and environmentally robust optoelectronic devices. We will report on our latest systematic experimental studies on radiation hardness and space qualifications of AlGaN optoelectronic devices: Deep UV Light Emitting Diodes (DUV LEDs) and solarblind UV Photodiodes (PDs). For custom designed AlGaN DUV LEDs with a central emission wavelength of 255 nm, we have demonstrated its extreme radiation hardness up to 2 x 10 12 protons/cm 2 with 63.9 MeV proton beams. We have demonstrated an operation lifetime of over 26,000 hours in a nitrogen rich environment, and 23,000 hours of operation in vacuum without significant power drop and spectral shift. The DUV LEDs with multiple packaging styles have passed stringent space qualifications with 14 g random vibrations, and 21 cycles of 100K temperature cycles. The driving voltage, current, emission spectra and optical power (V-I-P) operation characteristics exhibited no significant changes after the space environmental tests. The DUV LEDs will be used for photoelectric charge management in space flights. For custom designed AlGaN UV photodiodes with a central response wavelength of 255 nm, we have

Recent Developments of an Opto-Electronic THz Spectrometer for High-Resolution Spectroscopy.

Science.gov (United States)

Hindle, Francis; Yang, Chun; Mouret, Gael; Cuisset, Arnaud; Bocquet, Robin; Lampin, Jean-François; Blary, Karine; Peytavit, Emilien; Akalin, Tahsin; Ducournau, Guillaume

2009-01-01

A review is provided of sources and detectors that can be employed in the THz range before the description of an opto-electronic source of monochromatic THz radiation. The realized spectrometer has been applied to gas phase spectroscopy. Air-broadening coefficients of HCN are determined and the insensitivity of this technique to aerosols is demonstrated by the analysis of cigarette smoke. A multiple pass sample cell has been used to obtain a sensitivity improvement allowing transitions of the volatile organic compounds to be observed. A solution to the frequency metrology is presented and promises to yield accurate molecular line center measurements.

Recent Developments of an Opto-Electronic THz Spectrometer for High-Resolution Spectroscopy

Science.gov (United States)

Hindle, Francis; Yang, Chun; Mouret, Gael; Cuisset, Arnaud; Bocquet, Robin; Lampin, Jean-François; Blary, Karine; Peytavit, Emilien; Akalin, Tahsin; Ducournau, Guillaume

2009-01-01

A review is provided of sources and detectors that can be employed in the THz range before the description of an opto-electronic source of monochromatic THz radiation. The realized spectrometer has been applied to gas phase spectroscopy. Air-broadening coefficients of HCN are determined and the insensitivity of this technique to aerosols is demonstrated by the analysis of cigarette smoke. A multiple pass sample cell has been used to obtain a sensitivity improvement allowing transitions of the volatile organic compounds to be observed. A solution to the frequency metrology is presented and promises to yield accurate molecular line center measurements. PMID:22291552

Recent developments of truly stretchable thin film electronic and optoelectronic devices.

Science.gov (United States)

Zhao, Juan; Chi, Zhihe; Yang, Zhan; Chen, Xiaojie; Arnold, Michael S; Zhang, Yi; Xu, Jiarui; Chi, Zhenguo; Aldred, Matthew P

2018-03-29

Truly stretchable electronics, wherein all components themselves permit elastic deformation as the whole devices are stretched, exhibit unique advantages over other strategies, such as simple fabrication process, high integrity of entire components and intimate integration with curvilinear surfaces. In contrast to the stretchable devices using stretchable interconnectors to integrate with rigid active devices, truly stretchable devices are realized with or without intentionally employing structural engineering (e.g. buckling), and the whole device can be bent, twisted, or stretched to meet the demands for practical applications, which are beyond the capability of conventional flexible devices that can only bend or twist. Recently, great achievements have been made toward truly stretchable electronics. Here, the contribution of this review is an effort to provide a panoramic view of the latest progress concerning truly stretchable electronic devices, of which we give special emphasis to three kinds of thin film electronic and optoelectronic devices: (1) thin film transistors, (2) electroluminescent devices (including organic light-emitting diodes, light-emitting electrochemical cells and perovskite light-emitting diodes), and (3) photovoltaics (including organic photovoltaics and perovskite solar cells). We systematically discuss the device design and fabrication strategies, the origin of device stretchability and the relationship between the electrical and mechanical behaviors of the devices. We hope that this review provides a clear outlook of these attractive stretchable devices for a broad range of scientists and attracts more researchers to devote their time to this interesting research field in both industry and academia, thus encouraging more intelligent lifestyles for human beings in the coming future.

Transitions towards sustainable agriculture: the organic apiculture niche in an Argentinean cooperative

Directory of Open Access Journals (Sweden)

Maximiliano Vila Seoane

2017-05-01

Full Text Available This article argues that it is possible to transform innovation pathways in natural-resource-based industries towards more sustainable ones. In particular, it employs the socio-technical transitions framework to understand the structural barriers that the industrial agricultural system puts to COOPSOL, an Argentinean cooperative project of organic apiculture. The article is based on qualitative data that systematize, on the one hand, the pressures for continuity and change in the agricultural system. On the other hand, the data reveal the main perceptions of COOPSOL´s actors about the existing structural limits.

Research on the Mechanism of Cross Organizational Knowledge Sharing in BIM Competitive Environment

Directory of Open Access Journals (Sweden)

Zhong Wei

2017-01-01

Full Text Available Co-opetition under the environment of BIM implementation process because the level is not high resulting in the project BIM application value of incomplete knowledge sharing among organizations, thus establishing good knowledge can effectively solve this problem and achieve the overall benefit and benefit sharing mechanism in the project organization. This paper defines five competing modes according to the competing degree of organization between different BIM applications, including imperfect competition, competition, competition and cooperation, full cooperation and cooperation, and put forward the conceptual model and related assumptions. Analysis of the effect of path and effect of project determined in BIM application mode, the concurrence of knowledge sharing, efficiency and overall efficiency of the project within the organization through the survey and empirical results, and according to the proposed contract, the distribution of benefits and work three kinds of knowledge sharing mechanism implementation path.

Intergenerational Cooperation at the Workplace from the Management Perspective

Directory of Open Access Journals (Sweden)

Veingerl Čič Živa

2017-09-01

Full Text Available The labor market is currently experiencing employees of four generations. Each generation has different behavior patterns, attitudes, expectations, habits, and motivational mechanisms. As generational gaps play an important role in the business process, organizations have to find ways to balance the needs and views of different age groups. To overcome the negative outcomes arising from generational differences and to use the strengths of each generation, the implementation of comprehensive and proactive model of intergenerational cooperation, presented in the paper, is becoming the necessity for each organization because of the benefits.

Optoelectronics in TESLA, LHC and pi-of-the-sky experiments

CERN Document Server

Romaniuk, Ryszard; Simrock, Stefan; Wrochna, Grzegorz

2004-01-01

Optical and optoelectronics technologies are more and more widely used in the biggest world experiments of high energy and nuclear physics, as well as in the astronomy. The paper is a kind of a broad digest describing the usage of optoelectronics is such experiments and information about some of the involved teams. The described experiments include: TESLA linear accelerator and FEL, Compact Muon Solenoid at LHC and recently started pi-of-the-sky global gamma ray bursts (with associated optical flashes) observation experiment. Optoelectronics and photonics offer several key features which are either extending the technical parameters of existing solutions or adding quite new practical application possibilities. Some of these favorable features of photonic systems are: high selectivity of optical sensors, immunity to some kinds of noise processes, extremely broad bandwidth exchangeable for either terabit rate transmission or ultrashort pulse generation, parallel image processing capability, etc. The following g...

Optoelectronic properties of valence-state-controlled amorphous niobium oxide

Science.gov (United States)

Onozato, Takaki; Katase, Takayoshi; Yamamoto, Akira; Katayama, Shota; Matsushima, Koichi; Itagaki, Naho; Yoshida, Hisao; Ohta, Hiromichi

2016-06-01

In order to understand the optoelectronic properties of amorphous niobium oxide (a-NbO x ), we have investigated the valence states, local structures, electrical resistivity, and optical absorption of a-NbO x thin films with various oxygen contents. It was found that the valence states of Nb ion in a-NbO x films can be controlled from 5+  to 4+  by reducing oxygen pressure during film deposition at room temperature, together with changing the oxide-ion arrangement around Nb ion from Nb2O5-like to NbO2-like local structure. As a result, a four orders of magnitude reduction in the electrical resistivity of a-NbO x films was observed with decreasing oxygen content, due to the carrier generation caused by the appearance and increase of an oxygen-vacancy-related subgap state working as an electron donor. The tunable optoelectronic properties of a-NbO x films by valence-state-control with oxygen-vacancy formation will be useful for potential flexible optoelectronic device applications.

Simultaneous dual-functioning InGaN/GaN multiple-quantum-well diode for transferrable optoelectronics

Science.gov (United States)

Shi, Zheng; Yuan, Jialei; Zhang, Shuai; Liu, Yuhuai; Wang, Yongjin

2017-10-01

We propose a wafer-level procedure for the fabrication of 1.5-mm-diameter dual functioning InGaN/GaN multiple-quantum-well (MQW) diodes on a GaN-on-silicon platform for transferrable optoelectronics. Nitride semiconductor materials are grown on (111) silicon substrates with intermediate Al-composition step-graded buffer layers, and membrane-type MQW-diode architectures are obtained by a combination of silicon removal and III-nitride film backside thinning. Suspended MQW-diodes are directly transferred from silicon to foreign substrates such as metal, glass and polyethylene terephthalate by mechanically breaking the support beams. The transferred MQW-diodes display strong electroluminescence under current injection and photodetection under light irradiation. Interestingly, they demonstrate a simultaneous light-emitting light-detecting function, endowing the 1.5-mm-diameter MQW-diode with the capability of producing transferrable optoelectronics for adjustable displays, wearable optical sensors, multifunctional energy harvesting, flexible light communication and monolithic photonic circuit.

In situ UV-visible absorption during spin-coating of organic semiconductors: A new probe for organic electronics and photovoltaics

KAUST Repository

Abdelsamie, Maged; Zhao, Kui; Niazi, Muhammad Rizwan; Chou, Kang Wei; Amassian, Aram

2014-01-01

Spin-coating is the most commonly used technique for the lab-scale production of solution processed organic electronic, optoelectronic and photovoltaic devices. Spin-coating produces the most efficient solution-processed organic solar cells and has

76 FR 54235 - Supplement to the FY2010 Single-Source Cooperative Agreement With the World Health Organization...

Science.gov (United States)

2011-08-31

...''. BARDA currently funds the development of vaccine manufacturing capacity in ten developing and emerging-economy countries worldwide via a cooperative agreement with the World Health Organization (WHO). The... Research and Development Authority was developed and has been operational [[Page 54236

Adaptive Opportunistic Cooperative Control Mechanism Based on Combination Forecasting and Multilevel Sensing Technology of Sensors for Mobile Internet of Things

Directory of Open Access Journals (Sweden)

Yong Jin

2014-01-01

Full Text Available In mobile Internet of Things, there are many challenges, including sensing technology of sensors, how and when to join cooperative transmission, and how to select the cooperative sensors. To address these problems, we studied the combination forecasting based on the multilevel sensing technology of sensors, building upon which we proposed the adaptive opportunistic cooperative control mechanism based on the threshold values such as activity probability, distance, transmitting power, and number of relay sensors, in consideration of signal to noise ratio and outage probability. More importantly, the relay sensors would do self-test real time in order to judge whether to join the cooperative transmission, for maintaining the optimal cooperative transmission state with high performance. The mathematical analyses results show that the proposed adaptive opportunistic cooperative control approach could perform better in terms of throughput ratio, packet error rate and delay, and energy efficiency, compared with the direct transmission and opportunistic cooperative approaches.

Optoelectronic Evaluation and Loss Analysis of PEDOT:PSS/Si Hybrid Heterojunction Solar Cells.

Science.gov (United States)

Yang, Zhenhai; Fang, Zebo; Sheng, Jiang; Ling, Zhaoheng; Liu, Zhaolang; Zhu, Juye; Gao, Pingqi; Ye, Jichun

2017-12-01

The organic/silicon (Si) hybrid heterojunction solar cells (HHSCs) have attracted considerable attention due to their potential advantages in high efficiency and low cost. However, as a newly arisen photovoltaic device, its current efficiency is still much worse than commercially available Si solar cells. Therefore, a comprehensive and systematical optoelectronic evaluation and loss analysis on this HHSC is therefore highly necessary to fully explore its efficiency potential. Here, a thoroughly optoelectronic simulation is provided on a typical planar polymer poly (3,4-ethylenedioxy thiophene):polystyrenesulfonate (PEDOT:PSS)/Si HHSC. The calculated spectra of reflection and external quantum efficiency (EQE) match well with the experimental results in a full-wavelength range. The losses in current density, which are contributed by both optical losses (i.e., reflection, electrode shield, and parasitic absorption) and electrical recombination (i.e., the bulk and surface recombination), are predicted via carefully addressing the electromagnetic and carrier-transport processes. In addition, the effects of Si doping concentrations and rear surface recombination velocities on the device performance are fully investigated. The results drawn in this study are beneficial to the guidance of designing high-performance PEDOT:PSS/Si HHSCs.

Self-organized control in cooperative robots using a pattern formation principle

International Nuclear Information System (INIS)

Starke, Jens; Ellsaesser, Carmen; Fukuda, Toshio

2011-01-01

Self-organized modular approaches proved in nature to be robust and optimal and are a promising strategy to control future concepts of flexible and modular manufacturing processes. We show how this can be applied to a model of flexible manufacturing based on time-dependent robot-target assignment problems where robot teams have to serve manufacturing targets such that an objective function is optimized. Feasibility of the self-organized solutions can be guaranteed even for unpredictable situations like sudden changes in the demands or breakdowns of robots. As example an uncrewed space mission is visualized in a simulation where robots build a space station. - Highlights: → Adapting a pattern formation principle to control cooperative robots in a robust way. → Flexible manufacturing systems are modelled by time-dependent assignment problems. → Coupled selection equations guarantee feasibility of solutions. → Solution structure (permutations) is not destroyed by inhomogeneous growth rates. → Example of an uncrewed space mission shows effectivity and robustness.

Farmers' Cooperatives in the EU: Policies, Strategies and Organization

NARCIS (Netherlands)

Bijman, J.; Iliopoulos, C.

2014-01-01

The importance of cooperatives for European farmers has often been claimed but empirical studies to support this claim are scarce. This special issue presents a number of articles on the recent development and status of agricultural cooperatives in the European Union, based on original data

Links between internal and external cooperation in product development : An exploratory study

NARCIS (Netherlands)

Hillebrand, B; Biemans, WG

While there is an overwhelming amount of publications on cooperation in product development projects, they mainly,focus on cooperation between business functions within an organization (internal cooperation) or on cooperation between organizations (external cooperation). Yet the relationship between

Integrated graphene-based devices for optoelectronic applications

DEFF Research Database (Denmark)

Xiao, Sanshui

Graphene opens up for novel optoelectronic applications thanks to its high carrier mobility, ultralarge absorption bandwidth, and extremely fast material response. Here I present novel integrated grapheneplasmonic waveguide modulator showing high modulation depth, thus giving a promising way...

7 CFR 4285.2 - Cooperative agreement purposes.

Science.gov (United States)

2010-01-01

... agency to: (a) Conduct marketing research related to agricultural cooperatives. (b) Assist other organizations in conducting marketing research related to agricultural cooperatives. ... RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE COOPERATIVE AGREEMENTS Federal-State Research on...

Study of Mechanisms for Development and Strengthening of Water User Cooperatives (Case Study of Aras River Basin): Application of AHP Method

OpenAIRE

Rohallah maghabl

2014-01-01

Water user cooperatives were formed due to consideration to people's empowerment and participation in water investment and management. The purpose of this study was to investigate the mechanisms of development and strengthening of water user cooperatives in the Aras River Basin. The study population consisted of the management board members of the water user cooperatives in the Aras Basin in the year 2012. Respondents were selected by purposeful stratified sampling method. Having the data col...

Why mussels stick together : spatial self-organization affects the evolution of cooperation

NARCIS (Netherlands)

de Jager, Monique; Weissing, Franz J; van de Koppel, Johan

2017-01-01

Cooperation with neighbours may be crucial for the persistence of populations in stressful environments. Yet, cooperation is often not evolutionarily stable, since non-cooperative individuals can reap the benefits of cooperation without having to pay the costs associated with cooperation. Here we

Cooperative Dynamics in Lattice-Embedded Scale-Free Networks

International Nuclear Information System (INIS)

Shang Lihui; Zhang Mingji; Yang Yanqing

2009-01-01

We investigate cooperative behaviors of lattice-embedded scale-free networking agents in the prisoner's dilemma game model by employing two initial strategy distribution mechanisms, which are specific distribution to the most connected sites (hubs) and random distribution. Our study indicates that the game dynamics crucially depends on the underlying spatial network structure with different strategy distribution mechanism. The cooperators' specific distribution contributes to an enhanced level of cooperation in the system compared with random one, and cooperation is robust to cooperators' specific distribution but fragile to defectors' specific distribution. Especially, unlike the specific case, increasing heterogeneity of network does not always favor the emergence of cooperation under random mechanism. Furthermore, we study the geographical effects and find that the graphically constrained network structure tends to improve the evolution of cooperation in random case and in specific one for a large temptation to defect.

Modelling Cooperative Tumorigenesis in Drosophila

Science.gov (United States)

2018-01-01

The development of human metastatic cancer is a multistep process, involving the acquisition of several genetic mutations, tumour heterogeneity, and interactions with the surrounding microenvironment. Due to the complexity of cancer development in mammals, simpler model organisms, such as the vinegar fly, Drosophila melanogaster, are being utilized to provide novel insights into the molecular mechanisms involved. In this review, we highlight recent advances in modelling tumorigenesis using the Drosophila model, focusing on the cooperation of oncogenes or tumour suppressors, and the interaction of mutant cells with the surrounding tissue in epithelial tumour initiation and progression. PMID:29693007

Modelling Cooperative Tumorigenesis in Drosophila

Directory of Open Access Journals (Sweden)

Helena E. Richardson

2018-01-01

Full Text Available The development of human metastatic cancer is a multistep process, involving the acquisition of several genetic mutations, tumour heterogeneity, and interactions with the surrounding microenvironment. Due to the complexity of cancer development in mammals, simpler model organisms, such as the vinegar fly, Drosophila melanogaster, are being utilized to provide novel insights into the molecular mechanisms involved. In this review, we highlight recent advances in modelling tumorigenesis using the Drosophila model, focusing on the cooperation of oncogenes or tumour suppressors, and the interaction of mutant cells with the surrounding tissue in epithelial tumour initiation and progression.

Standard cell-based implementation of a digital optoelectronic neural-network hardware.

Science.gov (United States)

Maier, K D; Beckstein, C; Blickhan, R; Erhard, W

2001-03-10

A standard cell-based implementation of a digital optoelectronic neural-network architecture is presented. The overall structure of the multilayer perceptron network that was used, the optoelectronic interconnection system between the layers, and all components required in each layer are defined. The design process from VHDL-based modeling from synthesis and partly automatic placing and routing to the final editing of one layer of the circuit of the multilayer perceptrons are described. A suitable approach for the standard cell-based design of optoelectronic systems is presented, and shortcomings of the design tool that was used are pointed out. The layout for the microelectronic circuit of one layer in a multilayer perceptron neural network with a performance potential 1 magnitude higher than neural networks that are purely electronic based has been successfully designed.

Organic Molecular Solids

CERN Document Server

Schwoerer, Marcus

2007-01-01

This is the first comprehensive textbook on the physical aspects of organic solids. All phenomena which are necessary in order to understand modern technical applications are being dealt with in a way which makes the concepts of the topics accessible for students. The chapters - from the basics, production and characterization of organic solids and layers to organic semiconductors, superconductors and opto-electronical applications - have been arranged in a logical and well thought-out order.

Assessment of persistency and bioaccumulation in pesticide registration frameworks within the Organization for Economic Cooperation and Development.

NARCIS (Netherlands)

Montforts, Mark H M M

This article describes the results of a survey conducted in 2003 on methods used by different member countries within the Organization for Economic Cooperation and Development (OECD) to evaluate persistent and bioaccumulative pesticides. The objectives were to establish the differences in taking

States, social capital and cooperation: looking back on 'Governing the Commons'

Directory of Open Access Journals (Sweden)

Denise L. Anthony

2011-09-01

Full Text Available This paper reflects on Elinor Ostrom’s classic book, Governing the Commons, and much work in sociology, political science and organization studies that has appeared since its publication. We do so in order to expand our understanding of the conditions under which cooperation occurs resulting in the production of collective goods. We explore two issues that were underdeveloped in her book that have subsequently received much attention. First, we discuss how states can facilitate cooperative behavior short of coercively imposing it on actors. Second, we discuss how social capital can facilitate or undermine cooperative behavior. In both cases we focus on the important mechanisms by which each one contributes to the development of cooperative behavior and collective goods. We conclude by extending our arguments to a brief analysis of one of the world’s newest and largest collective goods – the Internet.

Pseudo-direct bandgap transitions in silicon nanocrystals: effects on optoelectronics and thermoelectrics

Science.gov (United States)

Singh, Vivek; Yu, Yixuan; Sun, Qi-C.; Korgel, Brian; Nagpal, Prashant

2014-11-01

While silicon nanostructures are extensively used in electronics, the indirect bandgap of silicon poses challenges for optoelectronic applications like photovoltaics and light emitting diodes (LEDs). Here, we show that size-dependent pseudo-direct bandgap transitions in silicon nanocrystals dominate the interactions between (photoexcited) charge carriers and phonons, and hence the optoelectronic properties of silicon nanocrystals. Direct measurements of the electronic density of states (DOS) for different sized silicon nanocrystals reveal that these pseudo-direct transitions, likely arising from the nanocrystal surface, can couple with the quantum-confined silicon states. Moreover, we demonstrate that since these transitions determine the interactions of charge carriers with phonons, they change the light emission, absorption, charge carrier diffusion and phonon drag (Seebeck coefficient) in nanoscaled silicon semiconductors. Therefore, these results can have important implications for the design of optoelectronics and thermoelectric devices based on nanostructured silicon.While silicon nanostructures are extensively used in electronics, the indirect bandgap of silicon poses challenges for optoelectronic applications like photovoltaics and light emitting diodes (LEDs). Here, we show that size-dependent pseudo-direct bandgap transitions in silicon nanocrystals dominate the interactions between (photoexcited) charge carriers and phonons, and hence the optoelectronic properties of silicon nanocrystals. Direct measurements of the electronic density of states (DOS) for different sized silicon nanocrystals reveal that these pseudo-direct transitions, likely arising from the nanocrystal surface, can couple with the quantum-confined silicon states. Moreover, we demonstrate that since these transitions determine the interactions of charge carriers with phonons, they change the light emission, absorption, charge carrier diffusion and phonon drag (Seebeck coefficient) in

Analysis on the Load Carrying Mechanism Integrated as Heterogeneous Co-operative Manipulator in a Walking Wheelchair

Science.gov (United States)

Rajay Vedaraj, I. S.; Jain, Ritika; Rao, B. V. A.

2014-07-01

After industrial robots came into existence during 1960, the technology of robotics with the design and analysis of robots in various forms in industries as well as in domestic applications were developed. Nowadays, along with the automotive sector the robots are producing a great impact in the form of quality and production rate to register their existence reliable in various other sectors also. Robotic technology has undergone various phase translations from being tortured as humanoids to the present day manipulators. Depending upon the various forms of its existence, robot manipulators are designed as serial manipulators and parallel manipulators. Individually both types can be proved effective though both have various drawbacks in design and the kinematic analysis. The versatility of robots can be increased by making them work in an environment where the same work volume is shared by more than one manipulator. This work volume can be identified as co-operative work volume of those manipulators. Here the interference of manipulators in the work volume of other manipulators is possible and is made obstacle free. The main advantage of co-operative manipulators is that when a number of independent manipulators are put together in a cooperative work envelope the efficiency and ability to perform tasks is greatly enhanced. The main disadvantage of the co-operative manipulators lies in the complication of its design even for a simple application, in almost all fields. In this paper, a cooperative design of robot manipulators to work in co-operative work environment is done and analysed for its efficacy. In the industrial applications when robotic manipulators are put together in more numbers, the trajectory planning becomes the tough task in the work cell. Proper design can remove the design defects of the cooperative manipulators and can be utilized in a more efficient way. In the proposed research paper an analysis is made on such a type of cooperative manipulator

Analysis on the Load Carrying Mechanism Integrated as Heterogeneous Co-operative Manipulator in a Walking Wheelchair

International Nuclear Information System (INIS)

Vedaraj, I S Rajay; Jain, Ritika; Rao, B V A

2014-01-01

After industrial robots came into existence during 1960, the technology of robotics with the design and analysis of robots in various forms in industries as well as in domestic applications were developed. Nowadays, along with the automotive sector the robots are producing a great impact in the form of quality and production rate to register their existence reliable in various other sectors also. Robotic technology has undergone various phase translations from being tortured as humanoids to the present day manipulators. Depending upon the various forms of its existence, robot manipulators are designed as serial manipulators and parallel manipulators. Individually both types can be proved effective though both have various drawbacks in design and the kinematic analysis. The versatility of robots can be increased by making them work in an environment where the same work volume is shared by more than one manipulator. This work volume can be identified as co-operative work volume of those manipulators. Here the interference of manipulators in the work volume of other manipulators is possible and is made obstacle free. The main advantage of co-operative manipulators is that when a number of independent manipulators are put together in a cooperative work envelope the efficiency and ability to perform tasks is greatly enhanced. The main disadvantage of the co-operative manipulators lies in the complication of its design even for a simple application, in almost all fields. In this paper, a cooperative design of robot manipulators to work in co-operative work environment is done and analysed for its efficacy. In the industrial applications when robotic manipulators are put together in more numbers, the trajectory planning becomes the tough task in the work cell. Proper design can remove the design defects of the cooperative manipulators and can be utilized in a more efficient way. In the proposed research paper an analysis is made on such a type of cooperative manipulator

Progress in complementary metal–oxide–semiconductor silicon photonics and optoelectronic integrated circuits

International Nuclear Information System (INIS)

Chen Hongda; Zhang Zan; Huang Beiju; Mao Luhong; Zhang Zanyun

2015-01-01

Silicon photonics is an emerging competitive solution for next-generation scalable data communications in different application areas as high-speed data communication is constrained by electrical interconnects. Optical interconnects based on silicon photonics can be used in intra/inter-chip interconnects, board-to-board interconnects, short-reach communications in datacenters, supercomputers and long-haul optical transmissions. In this paper, we present an overview of recent progress in silicon optoelectronic devices and optoelectronic integrated circuits (OEICs) based on a complementary metal–oxide–semiconductor-compatible process, and focus on our research contributions. The silicon optoelectronic devices and OEICs show good characteristics, which are expected to benefit several application domains, including communication, sensing, computing and nonlinear systems. (review)

Third-party punishment increases cooperation in children through (misaligned) expectations and conditional cooperation.

Science.gov (United States)

Lergetporer, Philipp; Angerer, Silvia; Glätzle-Rützler, Daniela; Sutter, Matthias

2014-05-13

The human ability to establish cooperation, even in large groups of genetically unrelated strangers, depends upon the enforcement of cooperation norms. Third-party punishment is one important factor to explain high levels of cooperation among humans, although it is still somewhat disputed whether other animal species also use this mechanism for promoting cooperation. We study the effectiveness of third-party punishment to increase children's cooperative behavior in a large-scale cooperation game. Based on an experiment with 1,120 children, aged 7 to 11 y, we find that the threat of third-party punishment more than doubles cooperation rates, despite the fact that children are rarely willing to execute costly punishment. We can show that the higher cooperation levels with third-party punishment are driven by two components. First, cooperation is a rational (expected payoff-maximizing) response to incorrect beliefs about the punishment behavior of third parties. Second, cooperation is a conditionally cooperative reaction to correct beliefs that third party punishment will increase a partner's level of cooperation.

Functional Carbon Nanocomposite, Optoelectronic, and Catalytic Coatings

Science.gov (United States)

Liang, Yu Teng

Over the past couple decades, fundamental research into carbon nanomaterials has produced a steady stream of groundbreaking physical science. Their record setting mechanical strength, chemical stability, and optoelectronic performance have fueled many optimistic claims regarding the breadth and pace of carbon nanotube and graphene integration. However, present synthetic, processing, and economic constraints have precluded these materials from many practical device applications. To overcome these limitations, novel synthetic techniques, processing methodologies, device geometries, and mechanistic insight were developed in this dissertation. The resulting advancements in material production and composite device performance have brought carbon nanomaterials ever closer to commercial implementation. For improved materials processing, vacuum co-deposition was first demonstrated as viable technique for forming carbon nanocomposite films without property distorting covalent modifications. Co-deposited nanoparticle, carbon nanotube, and graphene composite films enabled rapid device prototyping and compositional optimization. Cellulosic polymer stabilizers were then shown to be highly effective carbon nanomaterial dispersants, improving graphene production yields by two orders of magnitude in common organic solvents. By exploiting polarity interactions, iterative solvent exchange was used to further increase carbon nanomaterial dispersion concentrations by an additional order of magnitude, yielding concentrated inks. On top of their low causticity, these cellulosic nanomaterial inks have highly tunable viscosities, excellent film forming capacity, and outstanding thermal stability. These processing characteristics enable the efficient scaling of carbon nanomaterial coatings and device production using existing roll-to-roll fabrication techniques. Utilizing these process improvements, high-performance gas sensing, energy storage, transparent conductor, and photocatalytic

Mechanical characterization of porcine abdominal organs.

Science.gov (United States)

Tamura, Atsutaka; Omori, Kiyoshi; Miki, Kazuo; Lee, Jong B; Yang, King H; King, Albert I

2002-11-01

Typical automotive related abdominal injuries occur due to contact with the rim of the steering wheel, seatbelt and armrest, however, the rate is less than in other body regions. When solid abdominal organs, such as the liver, kidneys and spleen are involved, the injury severity tends to be higher. Although sled and pendulum impact tests have been conducted using cadavers and animals, the mechanical properties and the tissue level injury tolerance of abdominal solid organs are not well characterized. These data are needed in the development of computer models, the improvement of current anthropometric test devices and the enhancement of our understanding of abdominal injury mechanisms. In this study, a series of experimental tests on solid abdominal organs was conducted using porcine liver, kidney and spleen specimens. Additionally, the injury tolerance of the solid organs was deduced from the experimental data.

Optical Near-field Interactions and Forces for Optoelectronic Devices

Science.gov (United States)

Kohoutek, John Michael

Throughout history, as a particle view of the universe began to take shape, scientists began to realize that these particles were attracted to each other and hence came up with theories, both analytical and empirical in nature, to explain their interaction. The interaction pair potential (empirical) and electromagnetics (analytical) theories, both help to explain not only the interaction between the basic constituents of matter, such as atoms and molecules, but also between macroscopic objects, such as two surfaces in close proximity. The electrostatic force, optical force, and Casimir force can be categorized as such forces. A surface plasmon (SP) is a collective motion of electrons generated by light at the interface between two mediums of opposite signs of dielectric susceptibility (e.g. metal and dielectric). Recently, surface plasmon resonance (SPR) has been exploited in many areas through the use of tiny antennas that work on similar principles as radio frequency (RF) antennas in optoelectronic devices. These antennas can produce a very high gradient in the electric field thereby leading to an optical force, similar in concept to the surface forces discussed above. The Atomic Force Microscope (AFM) was introduced in the 1980s at IBM. Here we report on its uses in measuring these aforementioned forces and fields, as well as actively modulating and manipulating multiple optoelectronic devices. We have shown that it is possible to change the far field radiation pattern of an optical antenna-integrated device through modification of the near-field of the device. This modification is possible through change of the local refractive index or reflectivity of the "hot spot" of the device, either mechanically or optically. Finally, we have shown how a mechanically active device can be used to detect light with high gain and low noise at room temperature. It is the aim of several of these integrated and future devices to be used for applications in molecular sensing

Optoelectronic and nonlinear optical processes in low dimensional ...

Indian Academy of Sciences (India)

Optoelectronic process; nonlinear optical process; semiconductor. Quest for ever faster and intelligent information processing technologies has sparked ..... Schematic energy level diagram for the proposed 4-level model. States other than the.

Monocrystalline halide perovskite nanostructures for optoelectronic applications

NARCIS (Netherlands)

Khoram, P.

2018-01-01

Halide perovskites are a promising class of materials for incorporation in optoelectronics with higher efficiency and lower cost. The solution processability of these materials provides unique opportunities for simple nanostructure fabrication. In the first half of the thesis (chapter 2 and 3) we

Growth of pseudomorphic structures through organic epitaxy

International Nuclear Information System (INIS)

Kaviyil, Sreejith Embekkat; Sassella, Adele; Borghesi, Alessandro; Campione, Marcello; Su Genbo; He Youping; Chen Chenjia

2012-01-01

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.

Modelling of optoelectronic circuits based on resonant tunneling diodes

Science.gov (United States)

Rei, João. F. M.; Foot, James A.; Rodrigues, Gil C.; Figueiredo, José M. L.

2017-08-01

Resonant tunneling diodes (RTDs) are the fastest pure electronic semiconductor devices at room temperature. When integrated with optoelectronic devices they can give rise to new devices with novel functionalities due to their highly nonlinear properties and electrical gain, with potential applications in future ultra-wide-band communication systems (see e.g. EU H2020 iBROW Project). The recent coverage on these devices led to the need to have appropriated simulation tools. In this work, we present RTD based optoelectronic circuits simulation packages to provide circuit signal level analysis such as transient and frequency responses. We will present and discuss the models, and evaluate the simulation packages.

Recent Developments of an Opto-Electronic THz Spectrometer for High-Resolution Spectroscopy

Directory of Open Access Journals (Sweden)

Guillaume Ducournau

2009-11-01

Full Text Available A review is provided of sources and detectors that can be employed in the THz range before the description of an opto-electronic source of monochromatic THz radiation. The realized spectrometer has been applied to gas phase spectroscopy. Air-broadening coefficients of HCN are determined and the insensitivity of this technique to aerosols is demonstrated by the analysis of cigarette smoke. A multiple pass sample cell has been used to obtain a sensitivity improvement allowing transitions of the volatile organic compounds to be observed. A solution to the frequency metrology is presented and promises to yield accurate molecular line center measurements.

Opto-electronic DNA chip-based integrated card for clinical diagnostics.

Science.gov (United States)

Marchand, Gilles; Broyer, Patrick; Lanet, Véronique; Delattre, Cyril; Foucault, Frédéric; Menou, Lionel; Calvas, Bernard; Roller, Denis; Ginot, Frédéric; Campagnolo, Raymond; Mallard, Frédéric

2008-02-01

Clinical diagnostics is one of the most promising applications for microfluidic lab-on-a-chip or lab-on-card systems. DNA chips, which provide multiparametric data, are privileged tools for genomic analysis. However, automation of molecular biology protocol and use of these DNA chips in fully integrated systems remains a great challenge. Simplicity of chip and/or card/instrument interfaces is amongst the most critical issues to be addressed. Indeed, current detection systems for DNA chip reading are often complex, expensive, bulky and even limited in terms of sensitivity or accuracy. Furthermore, for liquid handling in the lab-on-cards, many devices use complex and bulky systems, either to directly manipulate fluids, or to ensure pneumatic or mechanical control of integrated valves. All these drawbacks prevent or limit the use of DNA-chip-based integrated systems, for point-of-care testing or as a routine diagnostics tool. We present here a DNA-chip-based protocol integration on a plastic card for clinical diagnostics applications including: (1) an opto-electronic DNA-chip, (2) fluid handling using electrically activated embedded pyrotechnic microvalves with closing/opening functions. We demonstrate both fluidic and electric packaging of the optoelectronic DNA chip without major alteration of its electronical and biological functionalities, and fluid control using novel electrically activable pyrotechnic microvalves. Finally, we suggest a complete design of a card dedicated to automation of a complex biological protocol with a fully electrical fluid handling and DNA chip reading.

Greed and Fear in Network Reciprocity: Implications for Cooperation among Organizations

Science.gov (United States)

Kitts, James A.; Leal, Diego F.; Felps, Will; Jones, Thomas M.; Berman, Shawn L.

2016-01-01

Extensive interdisciplinary literatures have built on the seminal spatial dilemmas model, which depicts the evolution of cooperation on regular lattices, with strategies propagating locally by relative fitness. In this model agents may cooperate with neighbors, paying an individual cost to enhance their collective welfare, or they may exploit cooperative neighbors and diminish collective welfare. Recent research has extended the model in numerous ways, incorporating behavioral noise, implementing other network topologies or adaptive networks, and employing alternative dynamics of replication. Although the underlying dilemma arises from two distinct dimensions—the gains for exploiting cooperative partners (Greed) and the cost of cooperating with exploitative partners (Fear)–most work following from the spatial dilemmas model has argued or assumed that the dilemma can be represented with a single parameter: This research has typically examined Greed or Fear in isolation, or a composite such as the K-index of Cooperation or the ratio of the benefit to cost of cooperation. We challenge this claim on theoretical grounds—showing that embedding interaction in networks generally leads Greed and Fear to have divergent, interactive, and highly nonlinear effects on cooperation at the macro level, even when individuals respond identically to Greed and Fear. Using computational experiments, we characterize both dynamic local behavior and long run outcomes across regions of this space. We also simulate interventions to investigate changes of Greed and Fear over time, showing how model behavior changes asymmetrically as boundaries in payoff space are crossed, leading some interventions to have irreversible effects on cooperation. We then replicate our experiments on inter-organizational network data derived from links through shared directors among 2,400 large US corporations, thus demonstrating our findings for Greed and Fear on a naturally-occurring network. In closing

Why mussels stick together: spatial self-organization affects the evolution of cooperation

NARCIS (Netherlands)

de Jager, M.; Weissing, F.J.; van de Koppel, J.

2017-01-01

Cooperation with neighbours may be crucial for the persistence of populations instressful environments. Yet, cooperation is often not evolutionarily stable, since noncooperativeindividuals can reap the benefits of cooperation without having to pay the costsassociated with cooperation. Here we show

OECD (Organization of Economic Cooperation and Development) oil demand

International Nuclear Information System (INIS)

Huntington, H.G.

1993-01-01

Econometric response surfaces for nine different world oil models are estimated for aggregate oil demand with in the developed countries of the Organization of Economic Cooperation and Development (OECD). The estimates are based upon scenario results reported for the 1989-2010 period in a recent model comparison study. The response surface approach provides a parsimonious summary of model responses. It enables one to estimate long-run price elasticities directly rather than to infer such responses from 20-year cross-scenario results. It also shows more directly the significant effect of initial demand conditions (in 1988) on future oil demand growth. Due to the dynamic nature of the oil demand response, past prices exert a strongly positive effect on future oil demands in some models, but little or even negative effect in other models. On the basis of this finding, we urge demand modellers to be much more explicit about what their systems reveal about the extent of disequilibrium embedded in their model's starting oil demand conditions. (author)

Basic opto-electronics on silicon for sensor applications

NARCIS (Netherlands)

Joppe, J.L.; Bekman, H.H.P.Th.; de Krijger, A.J.T.; Albers, H.; Chalmers, J.; Chalmers, J.D.; Holleman, J.; Ikkink, T.J.; Ikkink, T.; van Kranenburg, H.; Zhou, M.-J.; Zhou, Ming-Jiang; Lambeck, Paul

1994-01-01

A general platform for integrated opto-electronic sensor systems on silicon is proposed. The system is based on a hybridly integrated semiconductor laser, ZnO optical waveguides and monolithic photodiodes and electronic circuiry.

77 FR 65713 - Certain Optoelectronic Devices for Fiber Optic Communications, Components Thereof, and Products...

Science.gov (United States)

2012-10-30

... Fiber Optic Communications, Components Thereof, and Products Containing the Same; Notice of Institution... certain optoelectronic devices for fiber optic communications, components thereof, and products containing... optoelectronic devices for fiber optic communications, components thereof, and products containing the same that...

Fused thiophene-based conjugated polymers and their use in optoelectronic devices

Science.gov (United States)

Facchetti, Antonio; Marks, Tobin J.; Takai, Atsuro; Seger, Mark; Chen; , Zhihua

2017-07-18

The present teachings relate to polymeric compounds and their use as organic semiconductors in organic and hybrid optical, optoelectronic, and/or electronic devices such as photovoltaic cells, light emitting diodes, light emitting transistors, and field effect transistors. The disclosed compounds generally include as repeating units at least one annulated thienyl-vinylene-thienyl (TVT) unit and at least one other pi-conjugated unit. The annulated TVT unit can be represented by the formula: ##STR00001## where Cy.sup.1 and Cy.sup.2 can be a five- or six-membered carbocyclic ring. The annulated TVT unit can be optionally substituted at any available ring atom(s), and can be covalently linked to the other pi-conjugated unit via either the thiophene rings or the carbocyclic rings Cy.sup.1 and Cy.sup.2. The other pi-conjugated unit can be a conjugated linear linker including one or more unsaturated bonds, or a conjugated cyclic linker including one or more carbocyclic and/or heterocyclic rings.

Foreign cooperative technology development and transfer

International Nuclear Information System (INIS)

Schassburger, R.J.; Robinson, R.A.

1988-01-01

It is the policy of the US Department of Energy (DOE) that, in pursuing the development of mined geologic repositories in the United States, the waste isolation program will continue to actively support international cooperation and exchange activities that are judged to be in the best interest of the program and in compliance with the Nuclear Waste Policy Act of 1982, Sec. 223. Because there are common technical issues and because technology development often requires large expenditures of funds and dedication of significant capital resources, it is advantageous to cooperate with foreign organizations carrying out similar activities. The DOE's Office of Civilian Radioactive Waste Management is working on cooperative nuclear waste isolation technology development programs with the Organization for Economic Cooperation and Development/Nuclear Energy Agency (OECD/NEA), Canada's Atomic Energy of Canada, Limited (AECL), Sweden, Switzerland, and the Federal Republic of Germany. This paper describes recent technology results that have been obtained in DOE's foreign cooperative programs. Specific technology development studies are discussed for cooperative efforts with Canada, OECD/NEA, and a natural analog project in Brazil

Evolution, epigenetics and cooperation.

Science.gov (United States)

Bateson, Patrick

2014-04-01

Explanations for biological evolution in terms of changes in gene frequencies refer to outcomes rather than process. Integrating epigenetic studies with older evolutionary theories has drawn attention to the ways in which evolution occurs. Adaptation at the level of the gene is givingway to adaptation at the level of the organism and higher-order assemblages of organisms. These ideas impact on the theories of how cooperation might have evolved. Two of the theories, i.e. that cooperating individuals are genetically related or that they cooperate for self-interested reasons, have been accepted for a long time. The idea that adaptation takes place at the level of groups is much more controversial. However, bringing together studies of development with those of evolution is taking away much of the heat in the debate about the evolution of group behaviour.

Promotion of technical cooperation in the field of energy

Energy Technology Data Exchange (ETDEWEB)

Yu, Jung Kyung; Jung, Duk Yung; Suh, Seong Seog; Park, Myung Nam; Kim, Young Mi; Cho, Moo Kyung [Korea Inst. of Energy Research, Taejon (Korea, Republic of)

1995-12-01

This study aims to improve the quality of human resources and the capability of research and development through the promotion of technical cooperation with foreign energy organizations possessing advanced technologies, and at the same time to contribute to internationalizing energy technology through the active involvement in multilateral technical cooperation programs with international organizations. To attain these aims, practical cooperative relations has been strengthened with 34 organizations from 11 countries including 6 organizations with which new cooperative agreements has been concluded in 1995 from the USA, Australia, China, and Russia, through the promotion of the continuous exchange of information and personnel, and international joint projects. And also the positive participation in technical cooperation programs and research projects organized or sponsored by APEC, IEA, UNDP, UNESCO, WEC has been made. In addition, for the improvement in research capability, 200 researchers has been dispatched abroad for the presentation of papers, of for the discussion of joint research projects, and 30 foreign experts through diverse overseas personnel exchange programs including Brain Pool Program were invited for the contribution of advancing research projects. (author). 8 figs., 15 tabs.

Ultrafast dynamics and laser action of organic semiconductors

CERN Document Server

Vardeny, Zeev Valy

2009-01-01

Spurred on by extensive research in recent years, organic semiconductors are now used in an array of areas, such as organic light emitting diodes (OLEDs), photovoltaics, and other optoelectronics. In all of these novel applications, the photoexcitations in organic semiconductors play a vital role. Exploring the early stages of photoexcitations that follow photon absorption, Ultrafast Dynamics and Laser Action of Organic Semiconductors presents the latest research investigations on photoexcitation ultrafast dynamics and laser action in pi-conjugated polymer films, solutions, and microcavities.In the first few chapters, the book examines the interplay of charge (polarons) and neutral (excitons) photoexcitations in pi-conjugated polymers, oligomers, and molecular crystals in the time domain of 100 fs-2 ns. Summarizing the state of the art in lasing, the final chapters introduce the phenomenon of laser action in organics and cover the latest optoelectronic applications that use lasing based on a variety of caviti...

The evolution of cooperation in spatial groups

International Nuclear Information System (INIS)

Zhang Jianlei; Zhang Chunyan; Chu Tianguang

2011-01-01

Research highlights: → We propose a model of evolutionary games in which individuals are organized into networked groups. → We show that the social dilemma can be resolved and high cooperation levels are attained. → Larger average group size would lead to lower cooperation level but higher average payoffs. → The results show that higher expectations can bring the system with larger average payoffs. - Abstract: Much of human cooperation remains an evolutionary riddle. There is evidence that individuals are often organized into groups in many social situations. Inspired by this observation, we propose a simple model of evolutionary public goods games in which individuals are organized into networked groups. Here, nodes in the network represent groups; the edges, connecting the nodes, refer to the interactions between the groups. Individuals establish public goods games with partners in the same group and migrate among neighboring groups depending on their payoffs and expectations. We show that the paradigmatic public goods social dilemma can be resolved and high cooperation levels are attained in structured groups, even in relatively harsh conditions for cooperation. Further, by means of numerical simulations and mean-field analysis, we arrive at the result: larger average group size and milder cooperation environment would lead to lower cooperation level but higher average payoffs of the entire population. Altogether, these results emphasize that our understanding of cooperation can be enhanced by investigations of how spatial groups of individuals affect the evolution dynamics, which might help in explaining the emergence and evolution of cooperation.

Cooperatives management evaluation of four Savings and Credit Cooperatives of Quito, Ecuador

Directory of Open Access Journals (Sweden)

Richard Joel Alba Caluguillin

2017-07-01

Full Text Available The administrative management in cooperative enterprises develops in each of the stages of the administrative process of the traditional companies, which are planning, organization, direction and control, with the only difference that the savings and credit cooperatives comply with cooperative principles and values such as mutual aid, social responsibility, democracy, equality, equity and solidarity. The objective of this research was to evaluate the process of administrative management in four selected savings and credit cooperatives from Quito city, Ecuador, were applied theoretical and empirical methods of research. From the empirical point of view, a survey was applied getting results from this process. In general, in the cooperatives evaluated, it was recognized the importance of comprehensive management, strategic planning, motivation as a key element for good job performance, the effectiveness of formal communication channels and other aspects inherent in administrative management, although there are certain deficiencies that limit the results of the cooperative activity.

Evolution of Cooperation in Continuous Prisoner's Dilemma Games on Barabasi—Albert Networks with Degree-Dependent Guilt Mechanism

Science.gov (United States)

Wang, Xian-Jia; Quan, Ji; Liu, Wei-Bing

2012-05-01

This paper studies the continuous prisoner's dilemma games (CPDG) on Barabasi—Albert (BA) networks. In the model, each agent on a vertex of the networks makes an investment and interacts with all of his neighboring agents. Making an investment is costly, but which benefits its neighboring agents, where benefit and cost depend on the level of investment made. The payoff of each agent is given by the sum of payoffs it receives in its interactions with all its neighbors. Not only payoff, individual's guilty emotion in the games has also been considered. The negative guilty emotion produced in comparing with its neighbors can reduce the utility of individuals directly. We assume that the reduction amount depends on the individual's degree and a baseline level parameter. The group's cooperative level is characterized by the average investment of the population. Each player makes his investment in the next step based on a convex combination of the investment of his best neighbors in the last step, his best history strategies in the latest steps which number is controlled by a memory length parameter, and a uniformly distributed random number. Simulation results show that this degree-dependent guilt mechanism can promote the evolution of cooperation dramatically comparing with degree-independent guilt or no guilt cases. Imitation, memory, uncertainty coefficients and network structure also play determinant roles in the cooperation level of the population. All our results may shed some new light on studying the evolution of cooperation based on network reciprocity mechanisms.

Evolution of Cooperation in Continuous Prisoner's Dilemma Games on Barabasi-Albert Networks with Degree-Dependent Guilt Mechanism

International Nuclear Information System (INIS)

Wang Xianjia; Quan Ji; Liu Weibing

2012-01-01

This paper studies the continuous prisoner's dilemma games (CPDG) on Barabasi-Albert (BA) networks. In the model, each agent on a vertex of the networks makes an investment and interacts with all of his neighboring agents. Making an investment is costly, but which benefits its neighboring agents, where benefit and cost depend on the level of investment made. The payoff of each agent is given by the sum of payoffs it receives in its interactions with all its neighbors. Not only payoff, individual's guilty emotion in the games has also been considered. The negative guilty emotion produced in comparing with its neighbors can reduce the utility of individuals directly. We assume that the reduction amount depends on the individual's degree and a baseline level parameter. The group's cooperative level is characterized by the average investment of the population. Each player makes his investment in the next step based on a convex combination of the investment of his best neighbors in the last step, his best history strategies in the latest steps which number is controlled by a memory length parameter, and a uniformly distributed random number. Simulation results show that this degree-dependent guilt mechanism can promote the evolution of cooperation dramatically comparing with degree-independent guilt or no guilt cases. Imitation, memory, uncertainty coefficients and network structure also play determinant roles in the cooperation level of the population. All our results may shed some new light on studying the evolution of cooperation based on network reciprocity mechanisms. (interdisciplinary physics and related areas of science and technology)

Differential and Cooperative Cell Adhesion Regulates Cellular Pattern in Sensory Epithelia.

Science.gov (United States)

Togashi, Hideru

2016-01-01

Animal tissues are composed of multiple cell types arranged in complex and elaborate patterns. In sensory epithelia, including the auditory epithelium and olfactory epithelium, different types of cells are arranged in unique mosaic patterns. These mosaic patterns are evolutionarily conserved, and are thought to be important for hearing and olfaction. Recent progress has provided accumulating evidence that the cellular pattern formation in epithelia involves cell rearrangements, movements, and shape changes. These morphogenetic processes are largely mediated by intercellular adhesion systems. Differential adhesion and cortical tension have been proposed to promote cell rearrangements. Many different types of cells in tissues express various types of cell adhesion molecules. Although cooperative mechanisms between multiple adhesive systems are likely to contribute to the production of complex cell patterns, our current understanding of the cooperative roles between multiple adhesion systems is insufficient to entirely explain the complex mechanisms underlying cellular patterning. Recent studies have revealed that nectins, in cooperation with cadherins, are crucial for the mosaic cellular patterning in sensory organs. The nectin and cadherin systems are interacted with one another, and these interactions provide cells with differential adhesive affinities for complex cellular pattern formations in sensory epithelia, which cannot be achieved by a single mechanism.

Purely Organic Thermally Activated Delayed Fluorescence Materials for Organic Light-Emitting Diodes.

Science.gov (United States)

Wong, Michael Y; Zysman-Colman, Eli

2017-06-01

The design of thermally activated delayed fluorescence (TADF) materials both as emitters and as hosts is an exploding area of research. The replacement of phosphorescent metal complexes with inexpensive organic compounds in electroluminescent (EL) devices that demonstrate comparable performance metrics is paradigm shifting, as these new materials offer the possibility of developing low-cost lighting and displays. Here, a comprehensive review of TADF materials is presented, with a focus on linking their optoelectronic behavior with the performance of the organic light-emitting diode (OLED) and related EL devices. TADF emitters are cross-compared within specific color ranges, with a focus on blue, green-yellow, orange-red, and white OLEDs. Organic small-molecule, dendrimer, polymer, and exciplex emitters are all discussed within this review, as is their use as host materials. Correlations are provided between the structure of the TADF materials and their optoelectronic properties. The success of TADF materials has ushered in the next generation of OLEDs. © 2017 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Redundancy and cooperativity in the mechanics of compositely crosslinked filamentous networks.

Directory of Open Access Journals (Sweden)

Moumita Das

Full Text Available The cytoskeleton of living cells contains many types of crosslinkers. Some crosslinkers allow energy-free rotations between filaments and others do not. The mechanical interplay between these different crosslinkers is an open issue in cytoskeletal mechanics. Therefore, we develop a theoretical framework based on rigidity percolation to study a generic filamentous system containing both stretching and bond-bending forces to address this issue. The framework involves both analytical calculations via effective medium theory and numerical simulations on a percolating triangular lattice with very good agreement between both. We find that the introduction of angle-constraining crosslinkers to a semiflexible filamentous network with freely rotating crosslinks can cooperatively lower the onset of rigidity to the connectivity percolation threshold-a result argued for years but never before obtained via effective medium theory. This allows the system to ultimately attain rigidity at the lowest concentration of material possible. We further demonstrate that introducing angle-constraining crosslinks results in mechanical behaviour similar to just freely rotating crosslinked semflexible filaments, indicating redundancy and universality. Our results also impact upon collagen and fibrin networks in biological and bio-engineered tissues.

Organic-Inorganic Composites of Semiconductor Nanocrystals for Efficient Excitonics.

Science.gov (United States)

Guzelturk, Burak; Demir, Hilmi Volkan

2015-06-18

Nanocomposites of colloidal semiconductor nanocrystals integrated into conjugated polymers are the key to soft-material hybrid optoelectronics, combining advantages of both plastics and particles. Synergic combination of the favorable properties in the hybrids of colloidal nanocrystals and conjugated polymers offers enhanced performance and new functionalities in light-generation and light-harvesting applications, where controlling and mastering the excitonic interactions at the nanoscale are essential. In this Perspective, we highlight and critically consider the excitonic interactions in the organic-inorganic nanocomposites to achieve highly efficient exciton transfer through rational design of the nanocomposites. The use of strong excitonic interactions in optoelectronic devices can trigger efficiency breakthroughs in hybrid optoelectronics.

Optoelectronic properties of higher acenes, their BN analogue and substituted derivatives

International Nuclear Information System (INIS)

Armaković, Stevan; Armaković, Sanja J.; Holodkov, Vladimir; Pelemiš, Svetlana

2016-01-01

We have investigated optoelectronic properties of higher acenes: pentacene, hexacene, heptacene, octacene, nonacene, decacene and their boron-nitride (BN) analogues, within the framework of density functional theory (DFT). We have also investigated the optoelectronic properties of acenes modified by BN substitution. Calculated optoelectronic properties encompasses: oxidation and reduction potentials, electron and hole reorganization energies and energy difference between excited first singlet and triplet states ΔE(S_1−T_1). Oxidation and reduction potentials indicate significantly better stability of BN analogues, comparing with their all-carbon relatives. Although higher acenes possess lower electron and hole reorganization energies, with both best values much lower than 0.1 eV, their BN analogues also have competitive values of reorganization energies, especially for holes for which reorganization energy is also lower than 0.1 eV. On the other hand ΔE(S_1−T_1) is much better for BN analogues, having values that indicate that BN analogues are possible applicable for thermally activated delayed fluorescence. - Highlights: • Optoelectronic properties of structures based on higher acenes have been investigated. • Oxidation and reduction potentials together with reorganization energies are calculated. • TADF is analyzed through calculation of ΔE(S_1−T_1), which is much better for BN analogues. • Reorganization energies of acenes improve with the increase of number of benzene rings.

Enhancing electronic and optoelectronic performances of tungsten diselenide by plasma treatment.

Science.gov (United States)

Xie, Yuan; Wu, Enxiu; Hu, Ruixue; Qian, Shuangbei; Feng, Zhihong; Chen, Xuejiao; Zhang, Hao; Xu, Linyan; Hu, Xiaodong; Liu, Jing; Zhang, Daihua

2018-06-21

Transition metal dichalcogenides (TMDCs) have recently become spotlighted as nanomaterials for future electronic and optoelectronic devices. In this work, we develop an effective approach to enhance the electronic and optoelectronic performances of WSe2-based devices by N2O plasma treatment. The hole mobility and sheet density increase by 2 and 5 orders of magnitude, reaching 110 cm2 V-1 s-1 and 2.2 × 1012 cm-2, respectively, after the treatment. At the same time, the contact resistance (Rc) between WSe2 and its metal electrode drop by 5 orders of magnitude from 1.0 GΩ μm to 28.4 kΩ μm. The WSe2 photoconductor exhibits superior performance with high responsivity (1.5 × 105 A W-1), short response time (106). We have also built a lateral p-n junction on a single piece of WSe2 flake by selective plasma exposure. The junction reaches an exceedingly high rectifying ratio of 106, an excellent photoresponsivity of 2.49 A W-1 and a fast response of 8 ms. The enhanced optoelectronic performance is attributed to band-engineering through the N2O plasma treatment, which can potentially serve as an effective and versatile approach for device engineering and optimization in a wide range of electronic and optoelectronic devices based on 2D materials.

Highly Efficient Cooperative Catalysis by Co ^III (Porphyrin) Pairs in Interpenetrating Metal-Organic Frameworks

Energy Technology Data Exchange (ETDEWEB)

Lin, Zekai; Zhang, Zhi-Ming; Chen, Yu-Sheng; Lin, Wenbin (UC); (Xiamen)

2016-12-02

A series of porous twofold interpenetrated In-Co^III(porphyrin) metal–organic frameworks (MOFs) were constructed by in situ metalation of porphyrin bridging ligands and used as efficient cooperative catalysts for the hydration of terminal alkynes. The twofold interpenetrating structure brings adjacent Co^III(porphyrins) in the two networks parallel to each other with a distance of about 8.8 Å, an ideal distance for the simultaneous activation of both substrates in alkyne hydration reactions. As a result, the In-Co^III(porphyrin) MOFs exhibit much higher (up to 38 times) catalytic activity than either homogeneous catalysts or MOF controls with isolated Co^III(porphyrin) centers, thus highlighting the potential application of MOFs in cooperative catalysis.

Special Agents Can Promote Cooperation in the Population

Science.gov (United States)

Wang, Xin; Han, Jing; Han, Huawei

2011-01-01

Cooperation is ubiquitous in our real life but everyone would like to maximize her own profits. How does cooperation occur in the group of self-interested agents without centralized control? Furthermore, in a hostile scenario, for example, cooperation is unlikely to emerge. Is there any mechanism to promote cooperation if populations are given and play rules are not allowed to change? In this paper, numerical experiments show that complete population interaction is unfriendly to cooperation in the finite but end-unknown Repeated Prisoner's Dilemma (RPD). Then a mechanism called soft control is proposed to promote cooperation. According to the basic idea of soft control, a number of special agents are introduced to intervene in the evolution of cooperation. They comply with play rules in the original group so that they are always treated as normal agents. For our purpose, these special agents have their own strategies and share knowledge. The capability of the mechanism is studied under different settings. We find that soft control can promote cooperation and is robust to noise. Meanwhile simulation results demonstrate the applicability of the mechanism in other scenarios. Besides, the analytical proof also illustrates the effectiveness of soft control and validates simulation results. As a way of intervention in collective behaviors, soft control provides a possible direction for the study of reciprocal behaviors. PMID:22216202

Resonant infrared laser deposition of polymer-nanocomposite materials for optoelectronic applications

Science.gov (United States)

Park, Hee K.; Schriver, Kenneth E.; Haglund, Richard F.

2011-11-01

Polymers find a number of potentially useful applications in optoelectronic devices. These include both active layers, such as light-emitting polymers and hole-transport layers, and passive layers, such as polymer barrier coatings and light-management films. This paper reports the experimental results for polymer films deposited by resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) and resonant infrared pulsed laser deposition (RIR-PLD) for commercial optoelectronic device applications. In particular, light-management films, such as anti-reflection coatings, require refractive-index engineering of a material. However, refractive indices of polymers fall within a relatively narrow range, leading to major efforts to develop both low- and high-refractive-index polymers. Polymer nanocomposites can expand the range of refractive indices by incorporating low- or high-refractive-index nanoscale materials. RIR-MAPLE is an excellent technique for depositing polymer-nanocomposite films in multilayer structures, which are essential to light-management coatings. In this paper, we report our efforts to engineer the refractive index of a barrier polymer by combining RIR-MAPLE of nanomaterials (for example, high refractive-index TiO2 nanoparticles) and RIR-PLD of host polymer. In addition, we report on the properties of organic and polymer films deposited by RIR-MAPLE and/or RIR-PLD, such as Alq3 [tris(8-hydroxyquinoline) aluminum] and PEDOT:PSS [poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate)]. Finally, the challenges and potential for commercializing RIR-MAPLE/PLD, such as industrial scale-up issues, are discussed.

Sintering effect on the optoelectronic characteristics of HgSe nanoparticle films on plastic substrates

International Nuclear Information System (INIS)

Byun, Kwangsub; Cho, Kyoungah; Kim, Sangsig

2010-01-01

The optoelectronic characteristics of HgSe nanoparticle films spin-coated on flexible plastic substrates are investigated under the illumination of 1.3 μm wavelength light. The sintering process improves the optoelectronic characteristics of the HgSe nanoparticle films. The photocurrent of the sintered HgSe nanoparticle films under the illumination of 1.3 μm wavelength light is approximately 20 times larger in magnitude than that of the non-sintered films in air at room temperature. Moreover, the endurance of the flexible optoelectronic device investigated by the continuous substrate bending test reveals that the photocurrent efficiency changes negligibly up to 250 cycles.

Underlying Mechanisms of Cooperativity, Input Specificity, and Associativity of Long-Term Potentiation Through a Positive Feedback of Local Protein Synthesis

Directory of Open Access Journals (Sweden)

Lijie Hao

2018-05-01

Full Text Available Long-term potentiation (LTP is a specific form of activity-dependent synaptic plasticity that is a leading mechanism of learning and memory in mammals. The properties of cooperativity, input specificity, and associativity are essential for LTP; however, the underlying mechanisms are unclear. Here, based on experimentally observed phenomena, we introduce a computational model of synaptic plasticity in a pyramidal cell to explore the mechanisms responsible for the cooperativity, input specificity, and associativity of LTP. The model is based on molecular processes involved in synaptic plasticity and integrates gene expression involved in the regulation of neuronal activity. In the model, we introduce a local positive feedback loop of protein synthesis at each synapse, which is essential for bimodal response and synapse specificity. Bifurcation analysis of the local positive feedback loop of brain-derived neurotrophic factor (BDNF signaling illustrates the existence of bistability, which is the basis of LTP induction. The local bifurcation diagram provides guidance for the realization of LTP, and the projection of whole system trajectories onto the two-parameter bifurcation diagram confirms the predictions obtained from bifurcation analysis. Moreover, model analysis shows that pre- and postsynaptic components are required to achieve the three properties of LTP. This study provides insights into the mechanisms underlying the cooperativity, input specificity, and associativity of LTP, and the further construction of neural networks for learning and memory.

Precise, Self-Limited Epitaxy of Ultrathin Organic Semiconductors and Heterojunctions Tailored by van der Waals Interactions.

Science.gov (United States)

Wu, Bing; Zhao, Yinghe; Nan, Haiyan; Yang, Ziyi; Zhang, Yuhan; Zhao, Huijuan; He, Daowei; Jiang, Zonglin; Liu, Xiaolong; Li, Yun; Shi, Yi; Ni, Zhenhua; Wang, Jinlan; Xu, Jian-Bin; Wang, Xinran

2016-06-08

Precise assembly of semiconductor heterojunctions is the key to realize many optoelectronic devices. By exploiting the strong and tunable van der Waals (vdW) forces between graphene and organic small molecules, we demonstrate layer-by-layer epitaxy of ultrathin organic semiconductors and heterostructures with unprecedented precision with well-defined number of layers and self-limited characteristics. We further demonstrate organic p-n heterojunctions with molecularly flat interface, which exhibit excellent rectifying behavior and photovoltaic responses. The self-limited organic molecular beam epitaxy (SLOMBE) is generically applicable for many layered small-molecule semiconductors and may lead to advanced organic optoelectronic devices beyond bulk heterojunctions.

Mechanism of realization economic strategy of transport organization

Science.gov (United States)

Palkina, E. S.

2017-10-01

In modern conditions of economic globalization, high dynamism of external environment, economic strategy of transport organization plays an important role in maintaining its competitive advantages, long-term development. For effective achievement of set strategic goals it is necessary to use an adequate mechanism based on completeness and interrelation of its constituent instruments. The main objective of the study presented in this paper is to develop methodological provisions on formation the mechanism of realization economic strategy for transport organizations. The principles of its construction have been proposed, the key components have been defined. Finally, an attempt to implementation this mechanism into the transport organization management system has been realized.

Nanocellulose-based Translucent Diffuser for Optoelectronic Device Applications with Dramatic Improvement of Light Coupling.

Science.gov (United States)

Wu, Wei; Tassi, Nancy G; Zhu, Hongli; Fang, Zhiqiang; Hu, Liangbing

2015-12-09

Nanocellulose is a biogenerated and biorenewable organic material. Using a process based on 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)/NaClO/NaBr system, a highly translucent and light-diffusive film consisting of many layers of nanocellulose fibers and wood pulp microfibers was made. The film demonstrates a combination of large optical transmittance of ∼90% and tunable diffuse transmission of up to ∼78% across the visible and near-infrared spectra. The detailed characterizations of the film indicate the combination of high optical transmittance and haze is due to the film's large packing density and microstructured surface. The superior optical properties make the film a translucent light diffuser and applicable for improving the efficiencies of optoelectronic devices such as thin-film silicon solar cells and organic light-emitting devices.

Personality, Organizational Culture, and Cooperation: Evidence from a Business Simulation.

Science.gov (United States)

Chatman, Jennifer A.; Barsade, Sigal G.

1995-01-01

Explored personal and situational sources of cooperation. Assessed MBA students' disposition to cooperate and randomly assigned them to simulated organizations emphasizing either collectivistic or individualistic cultural values. Coworkers rated cooperative subjects in collectivistic cultures as most cooperative. Cooperative people were most…

Developing electronic cooperation tools: a case from norwegian health care.

Science.gov (United States)

Larsen, Eli; Mydske, Per Kristen

2013-06-19

Many countries aim to create electronic cooperational tools in health care, but the progress is rather slow. The study aimed to uncover how the authoritys' financing policies influence the development of electronic cooperational tools within public health care. An interpretative approach was used in this study. We performed 30 semistructured interviews with vendors, policy makers, and public authorities. Additionally, we conducted an extensive documentation study and participated in 18 workshops concerning information and communication technology (ICT) in Norwegian health care. We found that the interorganizational communication in sectors like health care, that have undergone an independent development of their internal information infrastructure would find it difficult to create electronic services that interconnect the organizations because such connections would affect all interconnected organizations within the heterogenic structure. The organizations would, to a large extent, depend on new functionality in existing information systems. Electronic patient records play a central role in all parts of the health care sector and therefore dependence is established to the information systems and theirs vendors. The Norwegian government authorities, which run more than 80% of the Norwegian health care, have not taken extraordinary steps to compensate for this dependency-the government's political philosophy is that each health care institution should pay for further electronic patient record development. However, cooperational tools are complex due to the number of players involved and the way they are intertwined with the overall workflow. The customers are not able to buy new functionalities on the drawing table, while the electronic patient record vendors are not willing to take the economic risk in developing cooperational tools. Thus, the market mechanisms in the domain are challenged. We also found that public projects that were only financed for the first

Ageing as a price of cooperation and complexity: self-organization of complex systems causes the gradual deterioration of constituent networks.

Science.gov (United States)

Kiss, Huba J M; Mihalik, Agoston; Nánási, Tibor; Ory, Bálint; Spiró, Zoltán; Soti, Csaba; Csermely, Peter

2009-06-01

The network concept is increasingly used for the description of complex systems. Here, we summarize key aspects of the evolvability and robustness of the hierarchical network set of macromolecules, cells, organisms and ecosystems. Listing the costs and benefits of cooperation as a necessary behaviour to build this network hierarchy, we outline the major hypothesis of the paper: the emergence of hierarchical complexity needs cooperation leading to the ageing (i.e. gradual deterioration) of the constituent networks. A stable environment develops cooperation leading to over-optimization, and forming an 'always-old' network, which accumulates damage, and dies in an apoptosis-like process. A rapidly changing environment develops competition forming a 'forever-young' network, which may suffer an occasional over-perturbation exhausting system resources, and causing death in a necrosis-like process. Giving a number of examples we demonstrate how cooperation evokes the gradual accumulation of damage typical to ageing. Finally, we show how various forms of cooperation and consequent ageing emerge as key elements in all major steps of evolution from the formation of protocells to the establishment of the globalized, modern human society.

How chimpanzees cooperate in a competitive world

Science.gov (United States)

Suchak, Malini; Eppley, Timothy M.; Campbell, Matthew W.; Feldman, Rebecca A.; Quarles, Luke F.; de Waal, Frans B. M.

2016-01-01

Our species is routinely depicted as unique in its ability to achieve cooperation, whereas our closest relative, the chimpanzee (Pan troglodytes), is often characterized as overly competitive. Human cooperation is assisted by the cost attached to competitive tendencies through enforcement mechanisms, such as punishment and partner choice. To examine if chimpanzees possess the same ability to mitigate competition, we set up a cooperative task in the presence of the entire group of 11 adults, which required two or three individuals to pull jointly to receive rewards. This open-group set-up provided ample opportunity for competition (e.g., freeloading, displacements) and aggression. Despite this unique set-up and initial competitiveness, cooperation prevailed in the end, being at least five times as common as competition. The chimpanzees performed 3,565 cooperative acts while using a variety of enforcement mechanisms to overcome competition and freeloading, as measured by (attempted) thefts of rewards. These mechanisms included direct protest by the target, third-party punishment in which dominant individuals intervened against freeloaders, and partner choice. There was a marked difference between freeloading and displacement; freeloading tended to elicit withdrawal and third-party interventions, whereas displacements were met with a higher rate of direct retaliation. Humans have shown similar responses in controlled experiments, suggesting shared mechanisms across the primates to mitigate competition for the sake of cooperation. PMID:27551075

Optoelectronic properties of higher acenes, their BN analogue and substituted derivatives

Energy Technology Data Exchange (ETDEWEB)

Armaković, Stevan, E-mail: stevan.armakovic@df.uns.ac.rs [University of Novi Sad, Faculty of Sciences, Department of Physics, Trg Dositeja Obradovića 4, 21000, Novi Sad (Serbia); Armaković, Sanja J. [University of Novi Sad, Faculty of Sciences, Department of Chemistry, Biochemistry and Environmental Protection, Trg Dositeja Obradovića 3, 21000, Novi Sad (Serbia); Holodkov, Vladimir [Educons University, Faculty of Sport and Tourism - TIMS, Radnička 30a, 21000, Novi Sad (Serbia); Pelemiš, Svetlana [University of East Sarajevo, Faculty of Technology, Karakaj bb, 75400, Zvornik, Republic of Srpska, Bosnia and Herzegovina (Bosnia and Herzegovina)

2016-02-15

We have investigated optoelectronic properties of higher acenes: pentacene, hexacene, heptacene, octacene, nonacene, decacene and their boron-nitride (BN) analogues, within the framework of density functional theory (DFT). We have also investigated the optoelectronic properties of acenes modified by BN substitution. Calculated optoelectronic properties encompasses: oxidation and reduction potentials, electron and hole reorganization energies and energy difference between excited first singlet and triplet states ΔE(S{sub 1}−T{sub 1}). Oxidation and reduction potentials indicate significantly better stability of BN analogues, comparing with their all-carbon relatives. Although higher acenes possess lower electron and hole reorganization energies, with both best values much lower than 0.1 eV, their BN analogues also have competitive values of reorganization energies, especially for holes for which reorganization energy is also lower than 0.1 eV. On the other hand ΔE(S{sub 1}−T{sub 1}) is much better for BN analogues, having values that indicate that BN analogues are possible applicable for thermally activated delayed fluorescence. - Highlights: • Optoelectronic properties of structures based on higher acenes have been investigated. • Oxidation and reduction potentials together with reorganization energies are calculated. • TADF is analyzed through calculation of ΔE(S{sub 1}−T{sub 1}), which is much better for BN analogues. • Reorganization energies of acenes improve with the increase of number of benzene rings.

International Scientific Cooperation in the Field of Spatial Studies

Directory of Open Access Journals (Sweden)

Pavel Aleksandrovich Minakir

2014-06-01

Full Text Available The paper discusses the existing structure of international cooperation of scientific organizations in the field of regional studies in different parts of the world. The authors define current major organizations that coordinate the work of scientific subdivisions in the field of regional studies in the whole world and also in Europe, North and South America and the Asia-Pacific region. The researchers offer the new term - ‘public-scientific partnership’ (PSP - and discuss PSP mechanisms and its implementation ways that may strengthen regional scientific research in Russia. The authors also debate the idea of creation of the Russian Association of Regional Science

Study on Banana Cooperatives in Hainan Province

OpenAIRE

Huang, Huide; Zhang, Wanzhen; Liu, Enping; Zhang, Xizhu

2013-01-01

This paper gives an overview of the distribution, member scale, production and operation of banana cooperatives in Hainan Province, and points out the market risk and natural risk faced by the production of banana cooperatives in Hainan Province. In order to promote the banana cooperatives to form new agricultural management system integrating organization and intensification, this paper puts forth the production and operation recommendations, such as joint production of banana cooperatives, ...

Commercialization issues and funding opportunities for high-performance optoelectronic computing modules

Science.gov (United States)

Hessenbruch, John M.; Guilfoyle, Peter S.

1997-01-01

Low power, optoelectronic integrated circuits are being developed for high speed switching and data processing applications. These high performance optoelectronic computing modules consist of three primary components: vertical cavity surface emitting lasers, diffractive optical interconnect elements, and detector/amplifier/laser driver arrays. Following the design and fabrication of an HPOC module prototype, selected commercial funding sources will be evaluated to support a product development stage. These include the formation of a strategic alliance with one or more microprocessor or telecommunications vendors, and/or equity investment from one or more venture capital firms.

Utilizing an ANP framework for prioritizing effective criteria on performance management in cooperative organization

Directory of Open Access Journals (Sweden)

Hosein Akhavan Alavi

2012-09-01

Full Text Available Performance management plays an essential role on increasing efficiency of business units. It helps find important barriers against a business unit helping us setup better strategies for handling troubles. In this paper, we present an empirical study to find important factors influencing performance management in cooperative organizations. The proposed study uses analytical hierarchy process to rank important factors in three groups of team level, individual and organization levels. The survey is based on receiving feedbacks from decision makers and making a pairwise comparison on measuring the relative importance of each criterion influencing performance management. The results of our survey indicate that setting appropriate standards for performance management is the most important item followed by relationship between organization structure and performance management, performance management based on future events. The other three factors including continuous improvement and updating systems, encouraging employee for change culture and relationship between future outlook and performance management are other important factors.

Waste Tank Organic Safety Project organic concentration mechanisms task. FY 1994 progress report

International Nuclear Information System (INIS)

Gerber, M.A.

1994-09-01

The Pacific Northwest Laboratory (PNL), Waste Tank Organic Safety Project is conducting research to support Westinghouse Hanford Company's (WHC) Waste Tank Safety Program, sponsored by the U.S. Department of Energy's Tank Farm Project Office. The goal of PNL's program is to provide a scientific basis for analyzing organics in Hanford's underground storage tanks (USTs) and for determining whether they are at concentrations that pose a potentially unsafe condition. Part of this research is directed toward determining what organic concentrations are safe by conducting research on organic aging mechanisms and waste energetics to assess the conditions necessary to produce an uncontrolled energy release in tanks due to reactions between the organics and the nitrate and nitrate salts in the tank wastes. The objective of the Organic Concentration Mechanisms Task is to assess the degree of localized enrichment of organics to be expected in the USTs due to concentration mechanisms. This report describes the progress of research conducted in FY 1994 on two concentration mechanisms of interest to the tank safety project: (1) permeation of a separate organic liquid phase into the interstitial spaces of the tank solids during the draining of free liquid from the tanks; and (2) concentration of organics on the surfaces of the solids due to adsorption. Three experiments were conducted to investigate permeation of air and solvent into a sludge simulant that is representative of single-shell tank sludge. The permeation behavior of air and solvent into the sludge simulant can be explained by the properties of the fluid pairs (air/supernate and solvent supernate) and the sludge. One important fluid property is the interfacial tension between the supernate and either the solvent or air. In general, the greater the interfacial tension between two fluids, the more difficult it will be for the air or solvent to displace the supernate during dewatering of the sludge

Sorption interactions of organic compounds with soils affected by agricultural olive mill wastewater.

Science.gov (United States)

Keren, Yonatan; Borisover, Mikhail; Bukhanovsky, Nadezhda

2015-11-01

The organic compound-soil interactions may be strongly influenced by changes in soil organic matter (OM) which affects the environmental fate of multiple organic pollutants. The soil OM changes may be caused by land disposal of various OM-containing wastes. One unique type of OM-rich waste is olive mill-related wastewater (OMW) characterized by high levels of OM, the presence of fatty aliphatics and polyphenolic aromatics. The systematic data on effects of the land-applied OMW on organic compound-soil interactions is lacking. Therefore, aqueous sorption of simazine and diuron, two herbicides, was examined in batch experiments onto three soils, including untreated and OMW-affected samples. Typically, the organic compound-soil interactions increased following the prior land application of OMW. This increase is associated with the changes in sorption mechanisms and cannot be attributed solely to the increase in soil organic carbon content. A novel observation is that the OMW application changes the soil-sorbent matrix in such a way that the solute uptake may become cooperative or the existing ability of a soil sorbent to cooperatively sorb organic molecules from water may become characterized by a larger affinity. The remarkable finding of this study was that in some cases a cooperative uptake of organic molecules by soils makes itself evident in distinct sigmoidal sorption isotherms rarely observed in soil sorption of non-ionized organic compounds; the cooperative herbicide-soil interactions may be characterized by the Hill model coefficients. However, no single trend was found for the effect of applied OMW on the mechanisms of organic compound-soil interactions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Acupuncture Mechanisms: Anesthesia, Analgesia and Protection on Organ Functions

Directory of Open Access Journals (Sweden)

Jing Wang

2015-01-01

Full Text Available Acupuncture, as a healing art in traditional Chinese medicine, has been widely used to treat various diseases. In the history of acupuncture anesthesia, in the past decades, mechanisms of acupuncture analgesia has been widely investigated, and in recent years, acupuncture protection on organ functions has attracted great interest. This review summarized the research progress on mechanisms of acupuncture for analgesia and its protection against organ function injury in anesthesia, and its perspective of analgesia, immunomodulation, neuroendocrine regulation and multiple organ protection. The current evidence supports that acupuncture analgesia and its organ protection in anesthesia is associated with the integration of neuroendocrine-immune networks in the level of neurotransmitters, cytokines, hormones, neuronal ensembles, lymphocytes, and endocrine cells. Although the mechanisms of acupuncture analgesia and its organ protection are still not completely understood, basic as well as clinic researches on the mechanisms and applications of acupuncture and related techniques are being carried out.

Electron microscopy study of advanced heterostructures for optoelectronics

NARCIS (Netherlands)

Katcki, J.; Ratajczak, J.; Phillipp, F.; Muszalski, J.; Bugajski, M.; Chen, J.X.; Fiore, A.

2003-01-01

The application of cross-sectional transmission electron microscopy and SEM to the investigation of optoelectronic devices are reviewed. Special attention was paid to the electron microscopy assessment of the growth perfection of such crucial elements of the devices like quantum wells, quantum dots,

Inducing Peer Pressure to Promote Cooperation

Science.gov (United States)

Mani, Ankur; Rahwan, Iyad; Pentland, Alex

2013-04-01

Cooperation in a large society of self-interested individuals is notoriously difficult to achieve when the externality of one individual's action is spread thin and wide on the whole society. This leads to the `tragedy of the commons' in which rational action will ultimately make everyone worse-off. Traditional policies to promote cooperation involve Pigouvian taxation or subsidies that make individuals internalize the externality they incur. We introduce a new approach to achieving global cooperation by localizing externalities to one's peers in a social network, thus leveraging the power of peer-pressure to regulate behavior. The mechanism relies on a joint model of externalities and peer-pressure. Surprisingly, this mechanism can require a lower budget to operate than the Pigouvian mechanism, even when accounting for the social cost of peer pressure. Even when the available budget is very low, the social mechanisms achieve greater improvement in the outcome.

Inducing peer pressure to promote cooperation.

Science.gov (United States)

Mani, Ankur; Rahwan, Iyad; Pentland, Alex

2013-01-01

Cooperation in a large society of self-interested individuals is notoriously difficult to achieve when the externality of one individual's action is spread thin and wide on the whole society. This leads to the 'tragedy of the commons' in which rational action will ultimately make everyone worse-off. Traditional policies to promote cooperation involve Pigouvian taxation or subsidies that make individuals internalize the externality they incur. We introduce a new approach to achieving global cooperation by localizing externalities to one's peers in a social network, thus leveraging the power of peer-pressure to regulate behavior. The mechanism relies on a joint model of externalities and peer-pressure. Surprisingly, this mechanism can require a lower budget to operate than the Pigouvian mechanism, even when accounting for the social cost of peer pressure. Even when the available budget is very low, the social mechanisms achieve greater improvement in the outcome.

Theory of muscle contraction mechanism with cooperative interaction among crossbridges.

Science.gov (United States)

Mitsui, Toshio; Ohshima, Hiroyuki

2012-01-01

The power stroke model was criticized and a model was proposed for muscle contraction mechanism (Mitsui, 1999). The proposed model was further developed and calculations based on the model well reproduced major experimental data on the steady filament sliding (Mitsui and Ohshima, 2008) and on the transient phenomena (Mitsui, Takai and Ohshima, 2011). In this review more weight is put on explanation of the basic ideas of the model, especially logical necessity of the model, leaving mathematical details to the above-mentioned papers. A thermodynamic relationship that any models based upon the sliding filament theory should fulfill is derived. The model which fulfills the thermodynamic relationship is constructed on the assumption that a myosin head bound to an actin filament forms a complex with three actin molecules. In shortening muscles, the complex moves along the actin filament changing the partner actin molecules with steps of about 5.5 nm. This process is made possible through cooperative interaction among cross-bridges. The ATP hydrolysis energy is liberated by fraction at each step through chemical reactions between myosin and actin molecules. The cooperativity among crossbridges disappears in length-clamped muscles, in agreement with experimental observations that the cross-bridge produces force independently in the isometric tetanus state. The distance of the head movement per ATP hydrolysis cycle is expected to be about 5.5 nm or a few times of it under the condition of the in vitro single head experiments. Calculation results are surveyed illustrating that they are in good agreement with major experimental observations.

Analysis of the operation of the organs of internal control in the non agricultural cooperatives of the county of Pinar del Rio

Directory of Open Access Journals (Sweden)

Alexis del Llano Sobrino

2016-12-01

Full Text Available The achievement of a good operation of any entity, demands a high efficiency in the acting of its organs of internal control. It guarantees it that they are detected and prevent the internal deficiencies that affect the achievement of the objectives of the company, on time either material, social and financial without to wait to that coming organisms from the exterior of the entity are those that detect the same ones. At the present time the Non Agricultural Cooperatives in Cuba, are not isolated of this problem, being evidenced structural and functional inadequacies of the organs of internal control in the same ones that affect their inspection processes as well as the control of the execution of the agreements of their General Assembly of Associates. For what is necessary to propose a structure and functions for the organs of the Non Agricultural Cooperatives that it contributes to the improvement of their internal control and consequently the improvement of their economic and social administration.

Development of optical sciences in Poland

Science.gov (United States)

Romaniuk, Ryszard S.

2013-10-01

Research and technical communities for optics, photonics and optoelectronics is grouped in this country in several organizations and institutions. These are: Photonics Society of Poland (PSP), Polish Committee of Optoelectronics of SEP, Photonics Section of KEiT PAN, Laser Club at WAT, and Optics Section of PTF. Each of these communities keeps slightly different specificity. PSP publishes a quarterly journal Photonics Letters of Poland, stimulates international cooperation, and organizes conferences during Industrial Fairs on Innovativeness. PKOpto SEP organizes didactic diploma competitions in optoelectronics. KEiT PAN takes patronage over national conferences in laser technology, optical fiber technology and communications, and photonics applications. SO-PTF has recently taken a decision to organize a cyclic event "Polish Optical Conference". The third edition of this conference PKO'2013 was held in Sandomierz on 30.06-04.07.2013. The conference scientific and technical topics include: quantum and nonlinear optics, photon physics, optic and technology of lasers and other sources of coherent radiation, optoelectronics, optical integrated circuits, optical fibers, medical optics, instrumental optics, optical spectroscopy, optical metrology, new optical materials, applications of optics, teaching in optics. This paper reviews chosen works presented during the III Polish Optical Conference (PKO'2013), representing the research efforts at different national institutions.

Integration of organic nanofibers by soft transfer techniques and nanostenciling

DEFF Research Database (Denmark)

Tavares, Luciana

, the application of an AC voltage to the transistor gate electrode causes sequential injection of holes and electrons into the organic material with subsequent strongly localized light emission upon charge carrier recombination. Their morphology enables the nanofibers to function as optical waveguides and part......Self-assembled semiconductor nanostructures are foreseen to have great impact on next generation miniaturized electronic and photonic devices. So far, submicron optoelectronic devices such as multicolor LEDs, lasers, and photodetectors have almost exclusively been demonstrated using inorganic...... nanowires due their excellent and well-behaved electrical properties combined with a decent mechanical strength that enables easy manipulation of these materials without damage. Organic semiconductors based on small molecules have several advantages over inorganic materials including lower cost, flexibility...

MECHANISMS OF BACTERIAL POLYHOSTALITY

Directory of Open Access Journals (Sweden)

Markova Yu.A.

2007-12-01

Full Text Available In the review data about factors of pathogenicity of the bacteria, capable to amaze both animals, and a plant are collected. Such properties of microorganisms as adhesion, secretion of some enzymes, mobility, a phenomenon of cooperative sensitivity - play an essential role at defeat of different organisms. They are used for many universal offensive strategy overcoming protection of an organism, irrespective of its evolutionary origin. Studying of these mechanisms, will allow to provide new approaches to monitoring illnesses.

Optoelectronics-related competence building in Japanese and Western firms

Science.gov (United States)

Miyazaki, Kumiko

1992-05-01

In this paper, an analysis is made of how different firms in Japan and the West have developed competence related to optoelectronics on the basis of their previous experience and corporate strategies. The sample consists of a set of seven Japanese and four Western firms in the industrial, consumer electronics and materials sectors. Optoelectronics is divided into subfields including optical communications systems, optical fibers, optoelectronic key components, liquid crystal displays, optical disks, and others. The relative strengths and weaknesses of companies in the various subfields are determined using the INSPEC database, from 1976 to 1989. Parallel data are analyzed using OTAF U.S. patent statistics and the two sets of data are compared. The statistical analysis from the database is summarized for firms in each subfield in the form of an intra-firm technology index (IFTI), a new technique introduced to assess the revealed technology advantage of firms. The quantitative evaluation is complemented by results from intensive interviews with the management and scientists of the firms involved. The findings show that there is a marked variation in the way firms' technological trajectories have evolved giving rise to strength in some and weakness in other subfields for the different companies, which are related to their accumulated core competencies, previous core business activities, organizational, marketing, and competitive factors.

Organic semiconductor photodiode based on indigo carmine/n-Si for optoelectronic applications

Science.gov (United States)

Ganesh, V.; Manthrammel, M. Aslam; Shkir, Mohd.; Yahia, I. S.; Zahran, H. Y.; Yakuphanoglu, F.; AlFaify, S.

2018-06-01

The fabrication of indigo carmine/n-Si photodiode has been done, and a robust dark and photocurrent-voltage ( I- V), capacitance vs. voltage ( C-V) and conductance vs. voltage ( G-V) studies were done over a wide range of applied voltage and frequencies. The surface morphology was assessed by atomic force microscope (AFM), and the grain size was measured to be about 66 nm. The reverse current increased with both increasing illumination intensity and bias potential, whereas the forward current increased exponentially with bias potential. The responsivity value was also calculated. Barrier height and ideality factor of diode were estimated through a log (I) vs log (V) plot, and obtained to be 0.843 and 4.75 eV, respectively. The Vbi values are found between 0.95 and 1.2V for frequencies ranging between 100 kHz and 1 MHz. The value of R s is found to be lower at higher frequencies which may be due to a certain distribution of localized interface states. A strong frequency and voltage dependency were observed for interface states density N ss in the present indigo carmine/n-Si photodiode, and this explained the observed capacitance and resistance variation with frequency. These results suggest that the fabricated diode has the potential to be applied in optoelectronic devices.

International cooperation workshop on CTBTO international cooperation and national implementation for states from East and Southern Africa

International Nuclear Information System (INIS)

2002-09-01

In pursuant to its 2002 programme of work, the Provisional Technical Secretariat (PTS) of the Preparatory Commission of the Comprehensive Nuclear-Test-Ban Treaty Organization organized a workshop on CTBTO international cooperation and national implementation for states from East and Southern Africa in Nairobi, Kenya, from 18 to 20 June 2002. The summary report on the workshop has been provided, covering ways and means of promoting regional cooperation. The list of participants and the programme outline are annexed thereto

International cooperation workshop on CTBTO international cooperation and national implementation for states from East and Southern Africa

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-09-01

In pursuant to its 2002 programme of work, the Provisional Technical Secretariat (PTS) of the Preparatory Commission of the Comprehensive Nuclear-Test-Ban Treaty Organization organized a workshop on CTBTO international cooperation and national implementation for states from East and Southern Africa in Nairobi, Kenya, from 18 to 20 June 2002. The summary report on the workshop has been provided, covering ways and means of promoting regional cooperation. The list of participants and the programme outline are annexed thereto.

Low-voltage organic electronics based on a gate-tunable injection barrier in vertical graphene-organic semiconductor heterostructures.

Science.gov (United States)

Hlaing, Htay; Kim, Chang-Hyun; Carta, Fabio; Nam, Chang-Yong; Barton, Rob A; Petrone, Nicholas; Hone, James; Kymissis, Ioannis

2015-01-14

The vertical integration of graphene with inorganic semiconductors, oxide semiconductors, and newly emerging layered materials has recently been demonstrated as a promising route toward novel electronic and optoelectronic devices. Here, we report organic thin film transistors based on vertical heterojunctions of graphene and organic semiconductors. In these thin heterostructure devices, current modulation is accomplished by tuning of the injection barriers at the semiconductor/graphene interface with the application of a gate voltage. N-channel devices fabricated with a thin layer of C60 show a room temperature on/off ratio >10(4) and current density of up to 44 mAcm(-2). Because of the ultrashort channel intrinsic to the vertical structure, the device is fully operational at a driving voltage of 200 mV. A complementary p-channel device is also investigated, and a logic inverter based on two complementary transistors is demonstrated. The vertical integration of graphene with organic semiconductors via simple, scalable, and low-temperature fabrication processes opens up new opportunities to realize flexible, transparent organic electronic, and optoelectronic devices.

Cooperative Security: New Horizons for International Order

National Research Council Canada - National Science Library

Cohen, Richard; Mihalka, Michael

2001-01-01

.... Both are controversial. Richard Cohen presents a compelling and highly original model of Cooperative Security -- a term that once was applied almost exclusively to the Organization for Security and Co-operation in Europe (OSCE...

Theoretical study on the cooperative exciton dissociation process based on dimensional and hot charge-transfer state effects in an organic photocell

International Nuclear Information System (INIS)

Shimazaki, Tomomi; Nakajima, Takahito

2016-01-01

This paper discusses the exciton dissociation process at the donor–acceptor interface in organic photocells. In our previous study, we introduced a local temperature to handle the hot charge-transfer (CT) state and calculated the exciton dissociation probability based on the 1D organic semiconductor model [T. Shimazaki and T. Nakajima, Phys. Chem. Chem. Phys. 17, 12538 (2015)]. Although the hot CT state plays an essential role in exciton dissociations, the probabilities calculated are not high enough to efficiently separate bound electron–hole pairs. This paper focuses on the dimensional (entropy) effect together with the hot CT state effect and shows that cooperative behavior between both effects can improve the exciton dissociation process. In addition, we discuss cooperative effects with site-disorders and external-electric-fields.

Noninvasive Optoelectronic Assessment of Induced Sagittal Imbalance Using the Vicon System.

Science.gov (United States)

Ould-Slimane, Mourad; Latrobe, Charles; Michelin, Paul; Chastan, Nathalie; Dujardin, Franck; Roussignol, Xavier; Gauthé, Rémi

2017-06-01

Spinal diseases often induce gait disorders with multifactorial origins such as lumbar pain, radicular pain, neurologic complications, or spinal deformities. However, radiography does not permit an analysis of spinal dynamics; therefore, sagittal balance dynamics during gait remain largely unexplored. This prospective and controlled pilot study assessed the Vicon system for detecting sagittal spinopelvic imbalance, to determine the correlations between optoelectronic and radiographic parameters. Reversible anterior sagittal imbalance was induced in 24 healthy men using a thoracolumbar corset. Radiographic, optoelectronic, and comparative analyses were conducted. Corset wearing induced significant variations in radiographic parameters indicative of imbalance; the mean C7-tilt and d/D ratio increased by 15° ± 7.4° and 359%, respectively, whereas the mean spinosacral angle decreased by 16.8° ± 8° (all P imbalance; the mean spinal angle increased by 15.4° ± 5.6° (P imbalance detected using the Vicon system. Optoelectronic C7'S1' correlated with radiographic C7-tilt and d/D ratio. Copyright © 2017 Elsevier Inc. All rights reserved.

Molecular Electrical Doping of Organic Semiconductors: Fundamental Mechanisms and Emerging Dopant Design Rules.

Science.gov (United States)

Salzmann, Ingo; Heimel, Georg; Oehzelt, Martin; Winkler, Stefanie; Koch, Norbert

2016-03-15

Today's information society depends on our ability to controllably dope inorganic semiconductors, such as silicon, thereby tuning their electrical properties to application-specific demands. For optoelectronic devices, organic semiconductors, that is, conjugated polymers and molecules, have emerged as superior alternative owing to the ease of tuning their optical gap through chemical variability and their potential for low-cost, large-area processing on flexible substrates. There, the potential of molecular electrical doping for improving the performance of, for example, organic light-emitting devices or organic solar cells has only recently been established. The doping efficiency, however, remains conspicuously low, highlighting the fact that the underlying mechanisms of molecular doping in organic semiconductors are only little understood compared with their inorganic counterparts. Here, we review the broad range of phenomena observed upon molecularly doping organic semiconductors and identify two distinctly different scenarios: the pairwise formation of both organic semiconductor and dopant ions on one hand and the emergence of ground state charge transfer complexes between organic semiconductor and dopant through supramolecular hybridization of their respective frontier molecular orbitals on the other hand. Evidence for the occurrence of these two scenarios is subsequently discussed on the basis of the characteristic and strikingly different signatures of the individual species involved in the respective doping processes in a variety of spectroscopic techniques. The critical importance of a statistical view of doping, rather than a bimolecular picture, is then highlighted by employing numerical simulations, which reveal one of the main differences between inorganic and organic semiconductors to be their respective density of electronic states and the doping induced changes thereof. Engineering the density of states of doped organic semiconductors, the Fermi

Organic mixed farms in the landscape of a brook valley. How can a co-operative of organic farms contribute to ecological and aesthetic qualities of a landscape?

NARCIS (Netherlands)

Kuiper, J.

1997-01-01

Under which conditions would an organic mixed farm co-operative contribute to the aesthetic and ecological quality of the landscape? The orientation of people in space and time is considered an important aspect of aesthetic quality. To facilitate orientation in space and time a landscape should

Maritime English for Communication and Cooperation.

Science.gov (United States)

Thiel, Teresa A.

Because most maritime accidents are caused by human error, notably breakdowns in communication or cooperation, and because English is the international maritime language, instruction in maritime English for communication and cooperation is an important element in maritime education. The International Maritime Organization, a specialized agency of…

Cooperative Change and the Myth of Rationality

OpenAIRE

Rokholt, Per Ove; Borgen, Svein Ole

2000-01-01

Much of the current research on agricultural cooperatives is biased towards weaknesses of the cooperative organization form. The literature says very little about the strengths and advantages of the cooperative form and what is necessary to develop the form's uniqueness into a sustainable competitive advantage. We argue that for cooperatives to remain viable and competitive, the advantages of the form must be clearly manifested. There is now a lack of systematic theorizing in this field. Typi...

POPULAR COOPERATIVE RECYCLING: THE CASE OF COOPERATIVE RECYCLABLE MATERIAL RIBEIRÃO PRETO

OpenAIRE

Mantovani, Daielly Melina Nassif; Leite, Maria FLavia Barbosa

2015-01-01

The social cooperatives, in view of supportive economy, are pointed as a necessity to social inclusion of many marginalized employees in the work market and society. Thisarticlepresentsthe case oftheRecycling Material Cooperativefrom Ribeirão Preto (Cooperativa dos Catadores de Material Reciclável de Ribeirão Preto). The cooperative, in partner with a non-governmental organization (Casa das Mangueiras) tries to improve the social conditions of the employees and their fair social inclusion. Th...

Efficiency in Microfinance Cooperatives

Directory of Open Access Journals (Sweden)

HARTARSKA, Valentina

2012-12-01

Full Text Available In recognition of cooperatives’ contribution to the socio-economic well-being of their participants, the United Nations has declared 2012 as the International Year of Cooperatives. Microfinance cooperatives make a large part of the microfinance industry. We study efficiency of microfinance cooperatives and provide estimates of the optimal size of such organizations. We employ the classical efficiency analysis consisting of estimating a system of equations and identify the optimal size of microfinance cooperatives in terms of their number of clients (outreach efficiency, as well as dollar value of lending and deposits (sustainability. We find that microfinance cooperatives have increasing returns to scale which means that the vast majority can lower cost if they become larger. We calculate that the optimal size is around $100 million in lending and half of that in deposits. We find less robust estimates in terms of reaching many clients with a range from 40,000 to 180,000 borrowers.

Cultivation of students' engineering designing ability based on optoelectronic system course project

Science.gov (United States)

Cao, Danhua; Wu, Yubin; Li, Jingping

2017-08-01

We carry out teaching based on optoelectronic related course group, aiming at junior students majored in Optoelectronic Information Science and Engineering. " Optoelectronic System Course Project " is product-designing-oriented and lasts for a whole semester. It provides a chance for students to experience the whole process of product designing, and improve their abilities to search literature, proof schemes, design and implement their schemes. In teaching process, each project topic is carefully selected and repeatedly refined to guarantee the projects with the knowledge integrity, engineering meanings and enjoyment. Moreover, we set up a top team with professional and experienced teachers, and build up learning community. Meanwhile, the communication between students and teachers as well as the interaction among students are taken seriously in order to improve their team-work ability and communicational skills. Therefore, students are not only able to have a chance to review the knowledge hierarchy of optics, electronics, and computer sciences, but also are able to improve their engineering mindset and innovation consciousness.

Determination and analysis of dispersive optical constants of some organic thin films

International Nuclear Information System (INIS)

Kaya, Y.; Taysioglu, A. A.; Peksoez, A.; Irez, G.; Derebasi, N.; Kaynak, G.

2010-01-01

Schiff bases are an important class of ligands in coordination chemistry and find extensive application in different fields. Recently, increased interest in organic thin film materials has arisen due to their extensive applications in the fields of mechanics, flexible electronics and optics. Optoelectronics is the area in which organic films and organic-inorganic nanostructures have found their main applications in the last decade. These organic thin films have been also used in a wide variety of applications such as Schottky diodes, solid state devices and optical sensors. The optical constants (refractive index, n; extinction coefficient, k and dielectric constant, e) of some organic thin films were determined using reflectance and transmittance spectra. Analysis of the basis absorption spectra was also carried out to determine optical band gap (Eg) and Urbach parameter (E0). A surface observation of these thin films was also carried out by an Atomic Force Microscope.

Nuclear physics and optoelectronics presence in industry, medicine and environment

International Nuclear Information System (INIS)

Robu, Maria; Peteu, Gh.

2000-01-01

This paper reveals applications of Nuclear Physics and Optoelectronics in numerous fields of interest in industry, medicine, environment. In the first part of the work basic elements are analyzed, among which: - the large possibilities offered by the investigation, analysis and testing techniques based on nuclear physics and optoelectronics; - the superior qualitative and quantitative characteristics of these techniques, with varied applicability in fields from industry, medicine and environment. These applications refers to: - elemental analyses of content and impurities; - non-destructive testing with X and gamma radiations; - investigations with radioactive and activable tracers in trophic chains as for instance, ground-vegetation-products-consumers-environment, including also the systemic pollution factors; - complex investigations in the interface tritium-vegetation-environment-humans; - techniques and radiopharmaceutical products for medical investigations; - determinations and automatic control for levels, density, thickness, humidity, surfaces covering; - monitoring by means of remote sensing for the evaluation of the environment, vegetation and pollution factors; - applications and production of laser and UV installations; - connections through optical fibres resistant to radiations; - imaging and medical bioengineering; - advances in X ray, laser and ultrasonic radiology; - monitoring with radiations beams. In the final part, there are presented examples of optoelectronics and nuclear physics applications in fields in industry, medicine and environment, with special stress on their basic characteristics and efficiency. (authors)

Conference Report: "Knowledge Organization in Cooperative Learning and Working Environments". 8th Conference of the International Society for Knowledge Organization (ISKO), German Chapter

OpenAIRE

Doris A. Ohnesorge; H. Peter Ohly

2003-01-01

The report gives an overview of a conference that recognized and focused upon the fundamentals of knowledge organization as well asked questions and offered solutions for practice. The primary emphasis was given to the application of cooperative learning and working environments. The special value of this conference was the focus of the presentations and detailed discussions on current topics in the information sciences. Although the spectrum ranged from scientific to organizational environme...

Fundamentals of Quantum Mechanics

Science.gov (United States)

Tang, C. L.

2005-06-01

Quantum mechanics has evolved from a subject of study in pure physics to one with a wide range of applications in many diverse fields. The basic concepts of quantum mechanics are explained in this book in a concise and easy-to-read manner emphasising applications in solid state electronics and modern optics. Following a logical sequence, the book is focused on the key ideas and is conceptually and mathematically self-contained. The fundamental principles of quantum mechanics are illustrated by showing their application to systems such as the hydrogen atom, multi-electron ions and atoms, the formation of simple organic molecules and crystalline solids of practical importance. It leads on from these basic concepts to discuss some of the most important applications in modern semiconductor electronics and optics. Containing many homework problems and worked examples, the book is suitable for senior-level undergraduate and graduate level students in electrical engineering, materials science and applied physics. Clear exposition of quantum mechanics written in a concise and accessible style Precise physical interpretation of the mathematical foundations of quantum mechanics Illustrates the important concepts and results by reference to real-world examples in electronics and optoelectronics Contains homeworks and worked examples, with solutions available for instructors

Introduction: cooperative learning

Directory of Open Access Journals (Sweden)

José-Manuel Serrano

2014-10-01

Full Text Available The principal objective of this revision is the recognition of cooperative learning as a highly effective strategy for the accomplishment of the general goals in learning. The different investigations assessed validate the potential that a cooperative organization of the classroom could entail for academic achievement, self-esteem, interpersonal attraction or social support. The solidity of the existing research contributes to its external and internal validity and, thus, to conclude that the results are consistent and can be extrapolated to different cultures, ethnic groups or countries.

Enhancing Cooperativity in Bifunctional Acid–Pd Catalysts with Carboxylic Acid-Functionalized Organic Monolayers

Energy Technology Data Exchange (ETDEWEB)

Coan, Patrick D. [Department of Chemical and Biological Engineering, University of Colorado—Boulder, Boulder, Colorado 80309, United States; Ellis, Lucas D. [Department of Chemical and Biological Engineering, University of Colorado—Boulder, Boulder, Colorado 80309, United States; Griffin, Michael B. [National Bioenergy Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States; Schwartz, Daniel K. [Department of Chemical and Biological Engineering, University of Colorado—Boulder, Boulder, Colorado 80309, United States; Medlin, J. Will [Department of Chemical and Biological Engineering, University of Colorado—Boulder, Boulder, Colorado 80309, United States

2018-03-01

Cooperative catalysts containing a combination of noble metal hydrogenation sites and Bronsted acid sites are critical for many reactions, including the deoxygenation (DO) of biomass-derived oxygenates in the upgrading of pyrolysis oil. One route toward the design of cooperative catalysts is to tether two different catalytically active functions so that they are in close proximity while avoiding undesirable interactions that can block active sites. Here, we deposited carboxylic acid (CA)-functionalized organophosphonate monolayers onto Al2O3-supported Pd nanoparticle catalysts to prepare bifunctional catalysts containing both Bronsted acid and metal sites. Modification with phosphonic acids (PAs) improved activity and selectivity for gas-phase DO reactions, but the degree of improvement was highly sensitive to both the presence and positioning of the CA group, suggesting a significant contribution from both the PA and CA sites. Short spacer lengths of 1-2 methylene groups between the phosphonate head and CA tail were found to yield the best DO rates and selectivities, whereas longer chains performed similarly to self-assembled monolayers having alkyl tails. Results from a combination of density functional theory and Fourier transform infrared spectroscopy suggested that the enhanced catalyst performance on the optimally positioned CAs was due to the generation of strong acid sites on the Al2O3 support adjacent to the metal. Furthermore, the high activity of these sites was found to result from a hydrogen-bonded cyclic structure involving cooperativity between the phosphonate head group and CA tail function. More broadly, these results indicate that functional groups tethered to supports via organic ligands can influence catalytic chemistry on metal nanoparticles.

Optoelectronic properties of doped hydrothermal ZnO thin films

KAUST Repository

Mughal, Asad J.; Carberry, Benjamin; Oh, Sang Ho; Myzaferi, Anisa; Speck, James S.; Nakamura, Shuji; DenBaars, Steven P.

2017-01-01

, or In were evaluated for their optoelectronic properties. Inductively coupled plasma atomic emission spectroscopy was used to determine the concentration of dopants within the ZnO films. While Al and Ga-doped films showed linear incorporation rates

77 FR 9225 - Allegheny Electric Cooperative, Inc., et al. v. PJM Interconnection, L.L.C.; Organization of PJM...

Science.gov (United States)

2012-02-16

...-58-010] Allegheny Electric Cooperative, Inc., et al. v. PJM Interconnection, L.L.C.; Organization of PJM States, Inc., et al. v. PJM Interconnection, L.L.C.; Notice of Filing Take notice that on February... by section 18.17.4 of the Amended and Restated Operating Agreement of PJM Interconnection, L.L.C. and...

Advances in wide bandgap SiC for optoelectronics

DEFF Research Database (Denmark)

Ou, Haiyan; Ou, Yiyu; Argyraki, Aikaterini

2014-01-01

Silicon carbide (SiC) has played a key role in power electronics thanks to its unique physical properties like wide bandgap, high breakdown field, etc. During the past decade, SiC is also becoming more and more active in optoelectronics thanks to the progress in materials growth and nanofabrication...

1st International Conference on Opto-Electronics and Applied Optics

CERN Document Server

Bhattacharya, Indrani

2015-01-01

The Proceedings of First International Conference on Opto-Electronics and Applied Optics 2014, IEM OPTRONIX 2014 presents the research contributions presented in the conference by researchers from both India and abroad. Contributions from established scientists as well as students are included. The book is organized to enable easy access to various topics of interest.   The first part includes the Keynote addresses by Phillip Russell, Max Planck Institute of the Light Sciences, Erlangen, Germany and Lorenzo Pavesi, University of Trento, Italy.   The second part focuses on the Plenary Talks given by eminent scientists, namely, Azizur Rahman, City University London, London; Bishnu Pal, President, The Optical Society of India; Kamakhya Ghatak, National Institute of Technology, Agartala; Kehar Singh, Former Professor, India Institute of Technology Delhi; Mourad Zghal, SUPCOM, University of Carthage, Tunisia; Partha Roy Chaudhuri, IIT Kharagpur; S K. Bhadra, CSIR-Central Glass and Ceramic Research Institute, Kol...

Graduate studies on optoelectronics in Argentina: an experience

Science.gov (United States)

Fernández, Juan C.; Garea, María. T.; Isaurralde, Silvia; Perez, Liliana I.; Raffo, Carlos A.

2014-07-01

The number of graduate programs in Optoelectronics in Argentina is scarce. The current Optics and Photonics Education Directory lists only three programs. One of them was launched in 2001 in the Facultad de Ingeniería (College of Engineering), Universidad de Buenos Aires (UBA). This was the first graduate program in the field, leading to a Master Degree in Optoelectronics. This decision arose from the demand of telecommunications industries and several estate- or private-funded research institutions working with us in the fields of lasers, optics, remote sensing, etc. A great bonus was the steady work, during several decades, of research groups in the College on the development of different type of lasers and optical non destructive tests and their engineering applications. As happened in many engineering graduate programs in Argentina at that time, few non full-time students could finish their studies, which called for 800 hours of traditional lecture-recitation classes, and the Master Thesis. In recent years Argentine Education authorities downsized the Master programs to 700 hours of blended learning and we redesigned the Graduate Optoelectronic Engineering Program to meet the challenge, dividing it in two successive one year programs, the first aimed at a professional training for almost immediate insertion in the labor market (called Especialización en Ingeniería Optoelectrónica), and the second (called Maestría en Ingeniería Optoelectrónica y Fotónica) aimed at a more academic and research target to comply with the UBA standards for Master degrees. The present work is a presentation of the new program design, which has begun in the current year.

Organic photosensitive cells grown on rough electrode with nano-scale morphology control

Science.gov (United States)

Yang, Fan [Piscataway, NJ; Forrest, Stephen R [Ann Arbor, MI

2011-06-07

An optoelectronic device and a method for fabricating the optoelectronic device includes a first electrode disposed on a substrate, an exposed surface of the first electrode having a root mean square roughness of at least 30 nm and a height variation of at least 200 nm, the first electrode being transparent. A conformal layer of a first organic semiconductor material is deposited onto the first electrode by organic vapor phase deposition, the first organic semiconductor material being a small molecule material. A layer of a second organic semiconductor material is deposited over the conformal layer. At least some of the layer of the second organic semiconductor material directly contacts the conformal layer. A second electrode is deposited over the layer of the second organic semiconductor material. The first organic semiconductor material is of a donor-type or an acceptor-type relative to the second organic semiconductor material, which is of the other material type.

The outbreak of cooperation among success-driven individuals under noisy conditions.

Science.gov (United States)

Helbing, Dirk; Yu, Wenjian

2009-03-10

According to Thomas Hobbes' Leviathan [1651; 2008 (Touchstone, New York), English Ed], "the life of man [is] solitary, poor, nasty, brutish, and short," and it would need powerful social institutions to establish social order. In reality, however, social cooperation can also arise spontaneously, based on local interactions rather than centralized control. The self-organization of cooperative behavior is particularly puzzling for social dilemmas related to sharing natural resources or creating common goods. Such situations are often described by the prisoner's dilemma. Here, we report the sudden outbreak of predominant cooperation in a noisy world dominated by selfishness and defection, when individuals imitate superior strategies and show success-driven migration. In our model, individuals are unrelated, and do not inherit behavioral traits. They defect or cooperate selfishly when the opportunity arises, and they do not know how often they will interact or have interacted with someone else. Moreover, our individuals have no reputation mechanism to form friendship networks, nor do they have the option of voluntary interaction or costly punishment. Therefore, the outbreak of prevailing cooperation, when directed motion is integrated in a game-theoretical model, is remarkable, particularly when random strategy mutations and random relocations challenge the formation and survival of cooperative clusters. Our results suggest that mobility is significant for the evolution of social order, and essential for its stabilization and maintenance.

Proposals for regional cooperation in Africa

International Nuclear Information System (INIS)

Kleywegt, R.J.

1999-01-01

The CTBTO Prep Com is overseeing the rapid establishment of the verification-related means for the future CTBTO. It encourages support and participation in its development and would like to ensure that ancillary benefits are identified and utilised. One such benefit is to be derived from the global expertise, data and information which are developed and generated through its activities. This is particularly so in the field of seismology where the rapidly developing field of engineering seismology is dependent on quality data over an extended period. A national seismological capability is essential for countries that wish/expect to develop rapidly in the next few decades. Tremendous benefit can be derived by utilizing the verification-related monitoring data and information products of the CTBTO Prep Com, by making the organization (International Cooperation Section) aware of all national seismological needs and by interacting with member states. A regional co-operative programme or structure could be of benefit to countries to link with the CTBTO Prep Com in Vienna or for addressing problems common to a region. There are a number of regional organisations in Africa that can house or provide some form of support to further the cause of envisaged regional co-operative endeavours. The terms of reference and mechanisms by which the regional endeavours will operate should preferably be set up by the participating states within each region

Japan's international cooperation programs on seismic safety of nuclear power plants

International Nuclear Information System (INIS)

Sanada, Akira

1997-01-01

MITI is promoting many international cooperation programs on nuclear safety area. The seismic safety of nuclear power plants (NPPs) is a one of most important cooperation areas. Experts from MITI and related organization join the multilateral cooperation programs carried out by international organization such as IAEA, OECD/NEA etc. MITI is also promoting bilateral cooperation programs such as information exchange meetings, training programs and seminars on nuclear safety with several countries. Concerning to the cooperation programs on seismic safety of NPPs such as information exchange and training, MITI shall continue and expand these programs. (J.P.N.)

International cooperation in peaceful use of nuclear energy

International Nuclear Information System (INIS)

Filatkin, A.P.

1985-01-01

Main forms of international cooperation in peaceful use of nuclear energy are described. IAEA represents the organization called to establish the cooperation. For the purposes of wide nuclear power usage IAEA provides technical assistance to developing countries, conducting of meetings and conferences, accomplishes wide publishing activity and nuclear information exchange with the use of different data bases, including the INIS system, and coordinates the operating group activity through the INTOR program. Cooperation of socialist countries is accomplished in the framework of the CMEA. JINR, intimately connected with scientific organization of other countries including CERN, represents the center of nuclear investigations in socialist countries

Optoelectronic inventory system for special nuclear material

International Nuclear Information System (INIS)

Sieradzki, F.H.

1994-01-01

In support of the Department of Energy's Dismantlement Program, the Optoelectronics Characterization and Sensor Development Department 2231 at Sandia National Laboratories/New Mexico has developed an in situ nonintrusive Optoelectronic Inventory System (OIS) that has the potential for application wherever periodic inventory of selected material is desired. Using a network of fiber-optic links, the OIS retrieves and stores inventory signatures from data storage devices (which are permanently attached to material storage containers) while inherently providing electromagnetic pulse immunity and electrical noise isolation. Photovoltaic cells (located within the storage facility) convert laser diode optic power from a laser driver to electrical energy. When powered and triggered, the data storage devices sequentially output their digital inventory signatures through light-emitting diode/photo diode data links for retrieval and storage in a mobile data acquisition system. An item's exact location is determined through fiber-optic network and software design. The OIS provides an on-demand method for obtaining acceptable inventory reports while eliminating the need for human presence inside the material storage facility. By using modularization and prefabricated construction with mature technologies and components, an OIS installation with virtually unlimited capacity can be tailored to the customer's requirements

High Charge Carrier Mobility Polymers for Organic Transistors

OpenAIRE

Erdmann, Tim

2017-01-01

I) Introduction p-Conjugated polymers inherently combine electronic properties of inorganic semiconductor crystals and material characteristics of organic plastics due to their special molecular design. This unique combination has led to developing new unconventional optoelectronic technologies and, further, resulted in the evolution of semiconducting polymers (SCPs) as fundamental components for novel electronic devices, such as organic field-effect transistors (OFETs), organic light-emit...

A full-duplex working integrated optoelectronic device for optical interconnect

Science.gov (United States)

Liu, Kai; Fan, Huize; Huang, Yongqing; Duan, Xiaofeng; Wang, Qi; Ren, Xiaomin; Wei, Qi; Cai, Shiwei

2018-05-01

In this paper, a full-duplex working integrated optoelectronic device is proposed. It is constructed by integrating a vertical cavity surface emitting laser (VCSEL) unit above a resonant cavity enhanced photodetector (RCE-PD) unit. Analysis shows that, the VCSEL unit has a threshold current of 1 mA and a slop efficiency of 0.66 W/A at 849.7 nm, the RCE-PD unit obtains its maximal absorption quantum efficiency of 90.24% at 811 nm with a FWHM of 4 nm. Moreover, the two units of the proposed integrated device can work independently from each other. So that the proposed integrated optoelectronic device can work full-duplex. It can be applied for single fiber bidirectional optical interconnects system.

Strategies of EU agro-food cooperatives to confront globalization: The case of wine cooperatives

Directory of Open Access Journals (Sweden)

Juan Sebastián Castillo Valero

2013-06-01

Full Text Available Due to globalization and market integration, the agro-food cooperative sector needs to be more competitive. This generates new challenges for cooperative enterprises in the agro-food sector. In this article the analysis of the wine producing sector is undertaken in the area of greatest world-wide wine production and commercialization, Castilla-La Mancha. EU wineries and cooperatives should propose strategic lines within an economy marked by a globalization process in world markets. The paradigmatic case is analyzed in this paper of the comparison of strategies followed by cooperatives confronting capitalist winery enterprises. Therefore, the degree of suitability is aimed to be elucidated and the success of the foundations of international commercial strategies that cooperative enterprises of the sector have followed, depending on their characteristics. Moreover, an exhaustive diagnosis is offered of the current strategic situation of cooperatives and their probability of gaining access to and/or growing in the international market. The parameters that have resulted significant are used as conclusions and recommendations so that cooperatives will reformulate their strategies and the organizations linked to the agro-food sector will know what factors to foment and support in their internationalization and global competitive positioning.

Cooperation and Development: a study of case in network cooperation

Directory of Open Access Journals (Sweden)

June Alisson Westarb Cruz

2009-03-01

Full Text Available The need to develop new surviving strategies and competitive advantage by individuals and organizations make cooperation to obtain complementary competences and potentialities very important, through the insertion of social actors in multiple networks of relationships and interactions.  This research was made in an Association Network of Carrinheiros[1] located in Curitiba and in the coast of Paraná.  The objective of the study was to analyze the structural characteristics of the network and its implications to develop collective actions. The data was collected through questionnaires, interviews, document analysis, and the daily direct observation of the network.  An interaction system between individuals and organizations from various sectors in society could be verified. This interaction stimulates the structured work connected to associations and cooperatives.  Between the actors of the network, concepts and realities are different, as well as individual objectives are distinct.  However, they converge to a common general objective that establish a common base for collaborative work.

Co-operatives and Normative Control

DEFF Research Database (Denmark)

Bregn, Kirsten; Jagd, Søren

1992-01-01

This paper explores the conditions for applying normative control in co-operatives. For normative control to be effective two conditions are found particularly important: Individuals must be morally involved and the organization must have a system of making it possible to link common norms...... and individual action. If these conditions are not fulfilled, as may be the case in many co-operatives, normative control cannot be expected to work. The problems of normative control in co-operatives may then not be caused by the use of normative control as such, but may instead be a problem of securing...

The Role of Vietnam in The ASEAN Regional Security Cooperation: From Mechanism Construction to Dispute Settlement

Directory of Open Access Journals (Sweden)

Li Chunxia

2016-12-01

Full Text Available In the context of the integration of ASEAN, Vietnam recognized that the strategic role of ASEAN is in its diplomacy. At the same time, to further improve the status in the region and in the international community, Vietnam has actively been participating in ASEAN affairs. Vietnam not only promoted the integration process of ASEAN, but also promoted the political security cooperation of ASEAN, in which Vietnam has advantages and wants to play a leading role. On the one hand, Vietnam promotes the construction of political security cooperation mechanisms, such as ARF, ADMM+, and so on; on the other hand, Vietnam took the South China Sea as a common concern, actively appeals for a common ASEAN position, to maximize its own benefit. Vietnam will further enhance and consolidate its status and role in ASEAN in the future.

Effects of R&D Cooperation to Innovation Performance in Open Innovation Environment

Directory of Open Access Journals (Sweden)

Gao Liang

2014-05-01

Full Text Available Dynamic nonlinear characteristics of internal and external environment in modern organization shows up increasingly, which make innovative research breakthrough organizational boundaries and present a pattern of open mode, the traditional mode of innovation is facing huge challenges like increasing innovation cycle, huge R&D input and inefficient knowledge transfer. And cooperation with external organizations to implement R&D is definitely a possibility to solve the open innovation environment challenge. Since organizations often have multiple dimensions of cooperation with different types of organization for research and development for the influence of organizational innovation performance or for exploring cooperation at the same time in different areas, and in different types of institutions. This paper studied the innovation performance of relevant government agencies except such innovation organization as enterprises, universities, and research institutions for the first time. This paper tracked on a survey of China's national engineering technology research center in related situation from 2002 to 2011 and collected related data to research and development cooperation and innovation performance for empirical research. Study found that universities have advantages in richness, in knowledge itself and knowledge accessible extent, cooperation with university in R&D is the best choice to promote the innovation performance of the organization. While cooperating with domestic universities and domestic enterprises to carry out research and development has bad effect in organizational innovation performance; while cooperation with domestic institutions and foreign institutions in the research and development plays a positive role in promoting innovation.

Rationalizing Cooperation: Moroccan Craft, Politics, and Education

Science.gov (United States)

Nicholas, Claire

2018-01-01

State attempts to rationalize Moroccan craft education reflect the ambivalent status of traditional knowledge in a modern economy. Female artisans, recently organized as a cooperative, navigate this ambivalence in a weaving "theory" class and in their "occupation" of the cooperative structure itself. During performances of…

Cooperative catalysis designing efficient catalysts for synthesis

CERN Document Server

Peters, René

2015-01-01

Written by experts in the field, this is a much-needed overview of the rapidly emerging field of cooperative catalysis. The authors focus on the design and development of novel high-performance catalysts for applications in organic synthesis (particularly asymmetric synthesis), covering a broad range of topics, from the latest progress in Lewis acid / Br?nsted base catalysis to e.g. metal-assisted organocatalysis, cooperative metal/enzyme catalysis, and cooperative catalysis in polymerization reactions and on solid surfaces. The chapters are classified according to the type of cooperating acti

Mechanisms and dynamics of cooperation and competition emergence in complex networked systems

Science.gov (United States)

Gianetto, David A.

Cooperative behavior is a pervasive phenomenon in human interactions and yet how it can evolve and become established, through the selfish process of natural selection, is an enduring puzzle. These behaviors emerge when agents interact in a structured manner; even so, the key structural factors that affect cooperation are not well understood. Moreover, the literature often considers cooperation a single attribute of primitive agents who do not react to environmental changes but real-world actors are more perceptive. The present work moves beyond these assumptions by evolving more realistic game participants, with memories of the past, on complex networks. Agents play repeated games with a three-part Markovian strategy that allows us to separate the cooperation phenomenon into trust, reciprocity, and forgiveness characteristics. Our results show that networks matter most when agents gain the most by acting in a selfish manner, irrespective of how much they may lose by cooperating; since the context provided by neighborhoods inhibits greedy impulses that agents otherwise succumb to in isolation. Network modularity is the most important driver of cooperation emergence in these high-stakes games. However, modularity fails to tell the complete story. Modular scale-free graphs impede cooperation when close coordination is required, partially due to the acyclic nature of scale-free network models. To achieve the highest cooperation in diverse social conditions, both high modularity, low connectivity within modules, and a rich network of long cycles become important. With these findings in hand, we study the influence of networks on coordination and competition within the federal health care insurance exchange. In this applied study, we show that systemic health care coordination is encouraged by the emergent insurance network. The network helps underpin the viability of the exchange and provides an environment of stronger competition once a critical-mass of insurers have

Evolution of cooperation: combining kin selection and reciprocal altruism into matrix games with social dilemmas.

Directory of Open Access Journals (Sweden)

Som B Ale

Full Text Available Darwinian selection should preclude cooperation from evolving; yet cooperation is widespread among organisms. We show how kin selection and reciprocal altruism can promote cooperation in diverse 2×2 matrix games (prisoner's dilemma, snowdrift, and hawk-dove. We visualize kin selection as non-random interactions with like-strategies interacting more than by chance. Reciprocal altruism emerges from iterated games where players have some likelihood of knowing the identity of other players. This perspective allows us to combine kin selection and reciprocal altruism into a general matrix game model. Both mechanisms operating together should influence the evolution of cooperation. In the absence of kin selection, reciprocal altruism may be an evolutionarily stable strategy but is unable to invade a population of non-co-operators. Similarly, it may take a high degree of relatedness to permit cooperation to supplant non-cooperation. Together, a little bit of reciprocal altruism can, however, greatly reduce the threshold at which kin selection promotes cooperation, and vice-versa. To properly frame applications and tests of cooperation, empiricists should consider kin selection and reciprocal altruism together rather than as alternatives, and they should be applied to a broader class of social dilemmas than just the prisoner's dilemma.

Enhanced Cooperation under the Lisbon Treaty

NARCIS (Netherlands)

Groenendijk, Nico

2011-01-01

Enhanced cooperation is often regarded as being a way out of EU decision-making deadlock and as a major possibility of proceeding with European integration in selected areas. Although the mechanism has been in place since the Treaty of Amsterdam, enhanced cooperation has only recently become a

GaN nano-membrane for optoelectronic and electronic device applications

KAUST Repository

Ooi, Boon S.

2014-01-01

The ~25nm thick threading dislocation free GaN nanomembrane was prepared using ultraviolet electroless chemical etching method offering the possibility of flexible integration of (Al,In,Ga)N optoelectronic and electronic devices.

Repeated thinking promotes cooperation in spatial prisoner's dilemma game

International Nuclear Information System (INIS)

Zhang Jun; Cai Kaiquan; Du Wenbo; Cao Xianbin

2012-01-01

Inspired by the realistic process of taking decisions in social life, we have proposed a repeated thinking mechanism in the evolutionary spatial prisoner's dilemma game where players are denoted by the vertices and play games with their direct neighbors. Under our mechanism, a player i will randomly select a neighbor j and then deliberate for M times before strategy updating. It will remain unchanged if not all M considerations suggest it to learn the strategy of j. We mainly focus on the evolution of cooperation in the systems. Interestingly, we find that the cooperation level f C is remarkably promoted and f C has a monotonic dependence on the caution parameter M, indicating that being cautious facilitates the emergence and persistence of cooperation. We give a simple but clear explanation for this cooperation promotion via detecting the cooperator-defector transition process. Moreover, the robustness of this mechanism is also examined on different noise levels and game models. (paper)

International cooperative information systems

International Nuclear Information System (INIS)

1980-01-01

Developing countries need mechanisms by which the information they generate themselves and development information from the rest of the world can be retrieved. The international cooperative information system is such a mechanism. Delegates to the Seminar on International Cooperative Information Systems were informed about various existing systems (INIS, AGRIS, INFOTERRA, TCDC/INRES, POPIN, DEVSIS, and INPADROC), some specialized information systems and services (CDS/ISIS and the Cassava Information Centre), and computer programs for information processing (INIS/AGRIS, CDS/ISIS, and MINISIS). The participants suggested some changes that should be made on both the national and the international levels to ensure that these systems meet the needs of developing countries more effectively. (LL)

Real-Time Observation of Order-Disorder Transformation of Organic Cations Induced Phase Transition and Anomalous Photoluminescence in Hybrid Perovskites.

Science.gov (United States)

Yang, Bin; Ming, Wenmei; Du, Mao-Hua; Keum, Jong K; Puretzky, Alexander A; Rouleau, Christopher M; Huang, Jinsong; Geohegan, David B; Wang, Xiaoping; Xiao, Kai

2018-05-01

A fundamental understanding of the interplay between the microscopic structure and macroscopic optoelectronic properties of organic-inorganic hybrid perovskite materials is essential to design new materials and improve device performance. However, how exactly the organic cations affect the structural phase transition and optoelectronic properties of the materials is not well understood. Here, real-time, in situ temperature-dependent neutron/X-ray diffraction and photoluminescence (PL) measurements reveal a transformation of the organic cation CH 3 NH 3 + from order to disorder with increasing temperature in CH 3 NH 3 PbBr 3 perovskites. The molecular-level order-to-disorder transformation of CH 3 NH 3 + not only leads to an anomalous increase in PL intensity, but also results in a multidomain to single-domain structural transition. This discovery establishes the important role that organic cation ordering has in dictating structural order and anomalous optoelectronic phenomenon in hybrid perovskites. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Simultaneous topographical, electrical and optical microscopy of optoelectronic devices at the nanoscale

KAUST Repository

Kumar, Naresh

2017-01-12

Novel optoelectronic devices rely on complex nanomaterial systems where the nanoscale morphology and local chemical composition are critical to performance. However, the lack of analytical techniques that can directly probe these structure-property relationships at the nanoscale presents a major obstacle to device development. In this work, we present a novel method for non-destructive, simultaneous mapping of the morphology, chemical composition and photoelectrical properties with <20 nm spatial resolution by combining plasmonic optical signal enhancement with electrical-mode scanning probe microscopy. We demonstrate that this combined approach offers subsurface sensitivity that can be exploited to provide molecular information with a nanoscale resolution in all three spatial dimensions. By applying the technique to an organic solar cell device, we show that the inferred surface and subsurface composition distribution correlates strongly with the local photocurrent generation and explains macroscopic device performance. For instance, the direct measurement of fullerene phase purity can distinguish between high purity aggregates that lead to poor performance and lower purity aggregates (fullerene intercalated with polymer) that result in strong photocurrent generation and collection. We show that the reliable determination of the structure-property relationship at the nanoscale can remove ambiguity from macroscopic device data and support the identification of the best routes for device optimisation. The multi-parameter measurement approach demonstrated herein is expected to play a significant role in guiding the rational design of nanomaterial-based optoelectronic devices, by opening a new realm of possibilities for advanced investigation via the combination of nanoscale optical spectroscopy with a whole range of scanning probe microscopy modes.

The cooperative game theory of networks and hierarchies

CERN Document Server

Gilles, Robert P

2010-01-01

This book details standard concepts in cooperative game theory with applications to the analysis of social networks and hierarchical authority organizations. It covers the multi-linear extension, the Core, the Shapley value, and the cooperative potential.

Subgame consistent cooperation a comprehensive treatise

CERN Document Server

Yeung, David W K

2016-01-01

Strategic behavior in the human and social world has been increasingly recognized in theory and practice. It is well known that non-cooperative behavior could lead to suboptimal or even highly undesirable outcomes. Cooperation suggests the possibility of obtaining socially optimal solutions and the calls for cooperation are prevalent in real-life problems. Dynamic cooperation cannot be sustainable if there is no guarantee that the agreed upon optimality principle at the beginning is maintained throughout the cooperation duration. It is due to the lack of this kind of guarantees that cooperative schemes fail to last till its end or even fail to get started. The property of subgame consistency in cooperative dynamic games and the corresponding solution mechanism resolve this “classic” problem in game theory. This book is a comprehensive treatise on subgame consistent dynamic cooperation covering the up-to-date state of the art analyses in this important topic. It sets out to provide the theory, solution tec...

3rd International Conference on Opto-Electronics and Applied Optics

CERN Document Server

Chakrabarti, Satyajit; Reehal, Haricharan; Lakshminarayanan, Vasudevan

2017-01-01

The Proceedings of 3rd International Conference on Opto-Electronics and Applied Optics, OPTRONIX 2016 is an effort to promote and present the research works by scientists and researchers including students in India and abroad in the area of Green Photonics and other related areas as well as to raise awareness about the recent trends of research and development in the area of the related fields. The book has been organized in such a way that it will be easier for the readers to go through and find out the topic of their interests. The first part includes the Keynote addresses by Rajesh Gupta, Department of Energy Science and Engineering, Indian Institute of Technology, Bombay; P.T. Ajith Kumar, President and Leading Scientist Light Logics Holography and Optics, Crescent Hill, Trivandrum, Kerala; and K.K. Ghosh, Institute of Engineering & Management, Kolkata, India.  The second part focuses on the Plenary and Invited Talks given by eminent scientists namely, Vasudevan Lakshminarayanan, University of Wate...

Divergent synthesis and optoelectronic properties of oligodiacetylene building blocks

NARCIS (Netherlands)

Pilzak, G.S.; Lagen, van B.; Sudhölter, E.J.R.; Zuilhof, H.

2008-01-01

A new and divergent synthetic route to oligodiacetylene (ODA) building blocks has been developed via Sonogashira reactions under a reductive atmosphere. These central building blocks provide a new way for rapid preparation of long ODAs. In addition, we report on their optoelectronic properties which

Stability and degradation mechanisms in organic solar cells

Energy Technology Data Exchange (ETDEWEB)

Ecker, Bernhard

2012-04-26

This thesis deals with stability improvements and the investigation of degradation mechanisms in organic solar cells. Organic solar cells have been in the focus of extensive academic research for over almost two decades and are currently entering the market in small scale applications. For successful large scale applications, next to the improvement of the power conversion efficiency, the stability of organic solar cells has to be increased. This thesis is dedicated to the investigation of novel materials and architectures to study stability-related issues and degradation mechanisms in order to contribute to the basic understanding of the working principles of organic solar cells. Here, impedance spectroscopy, a frequency domain technique, is used to gain information about stability and degradation mechanisms in organic solar cells. In combination with systematic variations in the preparation of solar cells, impedance spectroscopy gives the possibility to differentiate between interface and bulk dominated effects. Additionally, impedance spectroscopy gives access to the dielectric properties of the device, such as capacitance. This offers among other things the opportunity to probe the charge carrier concentration and the density of states. Another powerful way of evaluation is the combination of experimentally obtained impedance spectra with equivalent circuit modelling. The thesis presents results on novel materials and solar cell architectures for efficient hole and electron extraction. This indicates the importance of knowledge over interlayers and interfaces for improving both the efficiency and stability of organic solar cells.

Environmental influences on cooperation in social dilemmas on networks

Science.gov (United States)

Xie, Yunya; Chang, Shuhua; Yan, Ming; Zhang, Zhipeng; Wang, Xinyu

2018-02-01

Environmental influence on cooperation is a classical topic that is widely applicable to social interactions. Here, we introduce a realistic model which depends on both the payoff and the strategy of the environment. As the strategy of the environment rather than the neighbor is imitated with a probability, the model takes more attention on the comprehensive influence of the nearby neighbors. The simulation results show that the cooperation level can be widely enhanced for the prisoner's dilemma game and the snowdrift game with this environment factor. In this environmental model, the mechanism of the survival of cooperators is deeply studied, and the corresponding results can be derived. Although the survival of cooperators also depends on the formation of the cooperator clusters, the enhancement of the cooperation level can be interpreted as the accumulation effect of the transformation of defection into cooperation. Interestingly, there exists a threshold of the initial fraction of the cooperators, and the cooperation increases significantly when this threshold is reached Moreover, the square cooperative cluster is stable, and robust against different levels of the noise parameter and temptation in the strategy adoption process. This work may shed light on the mechanism of cooperation in the real world.

Degradation mechanisms in organic photovoltaic devices

NARCIS (Netherlands)

Grossiord, Nadia; Kroon, Jan M.; Andriessen, Ronn; Blom, Paul W. M.

In the present review, the main degradation mechanisms occurring in the different layer stacking (i.e. photoactive layer, electrode, encapsulation film, interconnection) of polymeric organic solar cells and modules are discussed. Bulk and interfacial, as well as chemical and physical degradation

An Opto-Electronic Sensor for Detecting Soil Microarthropods and Estimating Their Size in Field Conditions

Directory of Open Access Journals (Sweden)

Csongor I. Gedeon

2017-08-01

Full Text Available Methods to estimate density of soil-dwelling arthropods efficiently, accurately and continuously are critical for investigating soil biological activity and evaluating soil management practices. Soil-dwelling arthropods are currently monitored manually. This method is invasive, and time- and labor-consuming. Here we describe an infrared opto-electronic sensor for detection of soil microarthropods in the size range of 0.4–10 mm. The sensor is built in a novel microarthropod trap designed for field conditions. It allows automated, on-line, in situ detection and body length estimation of soil microarthropods. In the opto-electronic sensor the light source is an infrared LED. Two plano-convex optical lenses are placed along the virtual optical axis. One lens on the receiver side is placed between the observation space at 0.5–1 times its focal length from the sensor, and another emitter side lens is placed between the observation space and the light source in the same way. This paper describes the setup and operating mechanism of the sensor and the control unit, and through basic tests it demonstrates its potential in automated detection of soil microarthropods. The sensor may be used for monitoring activities, especially for remote observation activities in soil and insect ecology or pest control.

Partner Choice in Raven (Corvus corax) Cooperation.

Science.gov (United States)

Asakawa-Haas, Kenji; Schiestl, Martina; Bugnyar, Thomas; Massen, Jorg J M

2016-01-01

Although social animals frequently make decisions about when or with whom to cooperate, little is known about the underlying mechanisms of partner choice. Most previous studies compared different dyads' performances, though did not allow an actual choice among partners. We tested eleven ravens, Corvus corax, in triads, giving them first the choice to cooperate with either a highly familiar or a rather unfamiliar partner and, second, with either a friend or a non-friend using a cooperative string-pulling task. In either test, the ravens had a second choice and could cooperate with the other partner, given that this one had not pulled the string in the meantime. We show that during the experiments, these partner ravens indeed learn to wait and inhibit pulling, respectively. Moreover, the results of these two experiments show that ravens' preferences for a specific cooperation partner are not based on familiarity. In contrast, the ravens did show a preference based on relationship quality, as they did choose to cooperate significantly more with friends than with non-friends and they were also more proficient when cooperating with a friend. In order to further identify the proximate mechanism of this preference, we designed an open-choice experiment for the whole group where all birds were free to cooperate on two separate apparatuses. This set-up allowed us to distinguish between preferences for close proximity and preferences to cooperate. The results revealed that friends preferred staying close to each other, but did not necessarily cooperate with one another, suggesting that tolerance of proximity and not relationship quality as a whole may be the driving force behind partner choice in raven cooperation. Consequently, we stress the importance of experiments that allow such titrations and, suggest that these results have important implications for the interpretations of cooperation studies that did not include open partner choice.

The effect of wealth-based anti-expectation behaviors on public cooperation

Science.gov (United States)

Wang, Le; Chen, Tong; You, Xinshang; Wang, Yongjie

2018-03-01

Wealth difference is a common sense in our society. It is unreasonable to assume people have the same capability to donate money to the common pool in public goods game (PGG). Individuals have behavioral expectation towards their neighbors. In this paper, we introduce wealth-based anti-expectation mechanism to explore cooperation. Through numerical simulation results, we are glad to find that the anti-expectation mechanism could stimulate cooperation when the positive effects are equal to or larger than the negative effects from anti-expectation behaviors. Based on this mechanism, we propose propagation mechanism which aims to propagate the positive effects from the poor to inspire more people to choose cooperative strategies. When individuals are tolerant towards defectors, The fraction of cooperators increases with the increment of propagation distance. Enlarging the distance is not wise when individuals are harsh towards defectors. Additionally, we find that the more tolerant towards defectors we are, the higher the cooperation rate is in general. Therefore in PGG, we could consider one's anti-expectation towards others' behaviors and improve cooperation by propagating the poor's anti-expectation effects.

COOPERATION AND SUSTAINABILITY CASE STUDY OF A SOCIETY OF SOCIAL SOLIDARITY

Directory of Open Access Journals (Sweden)

Graciela Carrillo González

2013-04-01

Full Text Available Sustainability studies have been addressed from an economic, social, cultural, and environmental point of view. They have exceeded dimensions and developed mechanisms, which have involved various elements to establish cooperation and social networks. The aim of this paper is to analyze cooperation and establishment of farmers' organizations as critical factors in achieving sustainable local projects oriented to reforestation and land recovery, illustrating with the case of a triple S (Society of Social Solidarity, in the town of Zapotitlan Lagunas in the State of Oaxaca. Positive effects derived from these kinds of societies are reforestation in the area, land recovery, consolidation of social relationships and job creations. Therefore, thinking and acting locally is a condition to positively impact on the environment and add a social and economic vision can contribute to sustainability.

Japan`s international cooperation programs on seismic safety of nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Sanada, Akira [Agency of Natural Resources and Energy, Tokyo (Japan)

1997-03-01

MITI is promoting many international cooperation programs on nuclear safety area. The seismic safety of nuclear power plants (NPPs) is a one of most important cooperation areas. Experts from MITI and related organization join the multilateral cooperation programs carried out by international organization such as IAEA, OECD/NEA etc. MITI is also promoting bilateral cooperation programs such as information exchange meetings, training programs and seminars on nuclear safety with several countries. Concerning to the cooperation programs on seismic safety of NPPs such as information exchange and training, MITI shall continue and expand these programs. (J.P.N.)

Cooperative Cloud Service Aware Mobile Internet Coverage Connectivity Guarantee Protocol Based on Sensor Opportunistic Coverage Mechanism

Directory of Open Access Journals (Sweden)

Qin Qin

2015-01-01

Full Text Available In order to improve the Internet coverage ratio and provide connectivity guarantee, based on sensor opportunistic coverage mechanism and cooperative cloud service, we proposed the coverage connectivity guarantee protocol for mobile Internet. In this scheme, based on the opportunistic covering rules, the network coverage algorithm of high reliability and real-time security was achieved by using the opportunity of sensor nodes and the Internet mobile node. Then, the cloud service business support platform is created based on the Internet application service management capabilities and wireless sensor network communication service capabilities, which is the architecture of the cloud support layer. The cooperative cloud service aware model was proposed. Finally, we proposed the mobile Internet coverage connectivity guarantee protocol. The results of experiments demonstrate that the proposed algorithm has excellent performance, in terms of the security of the Internet and the stability, as well as coverage connectivity ability.

CTBT and the international technical cooperation

International Nuclear Information System (INIS)

Zhang Lixing

1999-01-01

Having in mind the basic aim of the CTBTO this presentation covers the fields of international co-operation as one of the most important and the cooperation of China and some International research and development institutions concerning the related subjects. One of the most important among international organizations being the IAEA, detailed list of general circumstances in the Chinese cooperation with IAEA is presented. It covers nuclear power plants construction and operation, safety of nuclear facilities, nuclear fuel cycle, radiation protection and waste management, industrial application, agricultural application, human health, fundamental research and information dissemination

Towards unified characterization of cooperation mechanisms. Comment on "Universal scaling for the dilemma strength in evolutionary games" by Z. Wang et al.

Science.gov (United States)

Han, The Anh

2015-09-01

"I will jump into the river to save two brothers or eight cousins": This famous quote by J.B.S. Haldane accurately anticipates the conditions under which cooperation is the favorable choice in an interaction between genetic relatives. The general condition can later be formulated as a surprisingly simple mathematical expression, known as the Hamilton's rule, stating that natural selection favors cooperation if the genetic relatedness (r) between the donor and the recipient of a cooperative act is greater than its cost (c) to benefit (b) ratio [1]: r > c / b. Motivated by Hamilton's elegant early studies, researchers have attempted to find simple and concise rules that characterize the conditions for cooperation to be selected under various social viscosity [2,3]. For example, the seminal work by M. Nowak [3] in 2006 shows that similarly simple rules can be derived that govern each of the other four popular mechanisms of cooperation-direct reciprocity, indirect reciprocity, group selection and network reciprocity-, which can be expressed via the cost-to-benefit ratio being smaller than some critical value associated with the mechanism at work (as seen, for kin interactions, the critical value is relatedness). However, these rules are restricted to the donor and recipient (D&R) paradigm. The question is thus whether it is possible to obtain simple rules even for the general case? The answer is not trivial as a general two-player game is described by four independent parameters, not just two as in the D&R game.

Dental impression technique using optoelectronic devices

Science.gov (United States)

Sinescu, Cosmin; Barua, Souman; Topala, Florin Ionel; Negrutiu, Meda Lavinia; Duma, Virgil-Florin; Gabor, Alin Gabriel; Zaharia, Cristian; Bradu, Adrian; Podoleanu, Adrian G.

2018-03-01

INTRODUCTION: The use of Optical Coherence Tomography (OCT) as a non-invasive and high precision quantitative information providing tool has been well established by researches within the last decade. The marginal discrepancy values can be scrutinized in optical biopsy made in three dimensional (3D) micro millimetre scale and reveal detailed qualitative and quantitative information of soft and hard tissues. OCT-based high resolution 3D images can provide a significant impact on finding recurrent caries, restorative failure, analysing the precision of crown preparation, and prosthetic elements marginal adaptation error with the gingiva and dental hard tissues. During the CAD/CAM process of prosthodontic restorations, the circumvent of any error is important for the practitioner and the technician to reduce waste of time and material. Additionally, OCT images help to achieve a new or semi-skilled practitioner to analyse their crown preparation works and help to develop their skills faster than in a conventional way. The aim of this study is to highlight the advantages of OCT in high precision prosthodontic restorations. MATERIALS AND METHODS: 25 preparations of frontal and lateral teeth were performed for 7 different patients. The impressions of the prosthetic fields were obtained both using a conventional optoelectronic system (Apolo Di, Syrona) and a Spectral Domain using OCT (Dental prototype, working at 860 nm). For the conventional impression technique the preparation margins were been prelevated by gingival impregnated cords. No specific treatments were performed by the OCT impression technique. RESULTS: The scanning performed by conventional optoelectronic system proved to be quick and accurate in terms of impression technology. The results were represented by 3D virtual models obtained after the scanning procedure was completed. In order to obtain a good optical impression a gingival retraction cord was inserted between the prepared tooth and the gingival

6th conference on Advances in Optoelectronics and Micro/nano-optics

International Nuclear Information System (INIS)