Spin-off strategies for the improvement of the performance national nuclear R and D project

International Nuclear Information System (INIS)

Lee, T. J.; Kim, H. J.; Jung, H. S.; Yang, M. H.; Choi, Y. M.

1998-01-01

In the light of the strategic utilization of the national R and D projects, this paper is to induce the spin-off strategies to improve the national R and D effectiveness through analyzing the spin-off characteristics of nuclear technologies, the spin-off status of the advanced countries and the case study of Korean nuclear spin-offs. Spin-off process is viewed as a three-stage operation, such as preparation stage, implementation stage and maintenance stage. In order to find the correlation between the influencing factors and spin-off effectiveness, the Spearman's correlation coefficient was employed as a specific statistical technique. By integrating this correlation, spin-off process and spin-off strategies, this paper presents an efficient frame work to improve the spin-off effectiveness

The need for a change in the paradigm of entrepreneurship at universities: differences between innovative spin-offs and technology-based spin-offs

Directory of Open Access Journals (Sweden)

Enara Zarrabeitia

2016-05-01

Full Text Available This study seeks to analyse the main characteristics of and barriers to the growth and development of innovative university spin-offs (which originate mainly from the fields of social science and law and technology-based university spin-offs (which tend to originate from the experimental sciences, from technical studies and from health science. The idea is to examine whether there is a need to redirect university policies aimed in the field of entrepreneurship. The study is based on a sample of 40 university spin-offs originating from the University of the Basque Country (UPV/EHU. A questionnaire was sent to entrepreneurs identified with the aid of the persons in charge of the university programmes for creating businesses at the UPV/EHU. To determine the main differences between innovative and technology-based spin-offs, once the replies were received a bivariate or contingent analysis was applied to characterise the two types of business. The main barriers to growth and development encountered by the two types were then identified. The data analysed reveal significant differences between the two types of business, and a need for a change in the paradigm of university entrepreneurship.

LAS SPIN-OFFS ACADÉMICAS Y SU POSIBLE CONFIGURACIÓN COMO EMPRESAS DE ECONOMÍA SOCIAL / THE ACADEMIC SPIN-OFFS AND SET AS SOCIAL ECONOMY ENTERPRISES.

Directory of Open Access Journals (Sweden)

Carlos VARGAS VASSEROT

2012-01-01

-Saxo terminology of companies operating a technology or knowledge transferred by a university and in which the partners are researchers at that institution (academic spin-offs. Although both fall into a broad term for Spin-off are not the same. While for companies that develop high technology and rapid development of graduates and colleges students doesn’t exist any problem to establish itself as social economy enterprises, to constitute a formal academic spin-off there are certain legal barriers. Researchers and business associates are often teachers who work full time and exclusively at the university, which prevents, in principle, be continuously performing a work activity or the provision of services in a private entity, which is the core of typical mutual activity of co-operatives and worker societies. Furthermore, if the University participates in the capital of the spin-off constituted, which is the tendency, the benefits of social economy enterprises are not as clear for the public organism which usually prefers to be a partner in a capital company.

The academic spin-offs as technology transfer way

International Nuclear Information System (INIS)

Gomez Gras, J. M.; Mira Solves, I.; Verdu Jover, A. J.; Sancho Azuar, J.

2007-01-01

One of the technology transfer mechanisms used by universities that has risen more interest in the last decade is the formation of academic spin-off, firms specifically created for the commercial exploitation of technology derived from research results. In the current paper we review the typologies and the development process of this kind of firms, as well as we propose a model that groups the conditioning factors of spin-off activity in the internal university environment. (Author) 92 refs

Rapidly solidified prealloyed powders by laser spin atomization

Science.gov (United States)

Konitzer, D. G.; Walters, K. W.; Heiser, E. L.; Fraser, H. L.

1984-01-01

A new technique, termed laser spin atomization, for the production of rapidly solidified prealloyed powders is described. The results of experiments involving the production of powders of two alloys, one based on Ni, the other on Ti, are presented. The powders have been characterized using light optical metallography, scanning electron microscopy, energy dispersive X-ray spectroscopy, and Auger elec-tron spectroscopy, and these various observations are described.

Spin-locking of half-integer quadrupolar nuclei in NMR of solids: The far off-resonance case.

Science.gov (United States)

Odedra, Smita; Wimperis, Stephen

Spin-locking of spin I=3/2 and I=5/2 nuclei in the presence of large resonance offsets has been studied using both approximate and exact theoretical approaches and, in the case of I=3/2, experimentally. We show the variety of coherences and population states produced in a far off-resonance spin-locking NMR experiment (one consisting solely of a spin-locking pulse) and how these vary with the radiofrequency field strength and offset frequency. Under magic angle spinning (MAS) conditions and in the "adiabatic limit", these spin-locked states acquire a time dependence. We discuss the rotor-driven interconversion of the spin-locked states, using an exact density matrix approach to confirm the results of the approximate model. Using conventional and multiple-quantum filtered spin-locking 23 Na (I=3/2) NMR experiments under both static and MAS conditions, we confirm the results of the theoretical calculations, demonstrating the applicability of the approximate theoretical model to the far off-resonance case. This simplified model includes only the effects of the initial rapid dephasing of coherences that occurs at the start of the spin-locking period and its success in reproducing both experimental and exact simulation data indicates that it is this dephasing that is the dominant phenomenon in NMR spin-locking of quadrupolar nuclei, as we have previously found for the on-resonance and near-resonance cases. Potentially, far off-resonance spin-locking of quadrupolar nuclei could be of interest in experiments such as cross polarisation as a consequence of the spin-locking pulse being applied to a better defined initial state (the thermal equilibrium bulk magnetisation aligned along the z-axis) than can be created in a powdered solid with a selective radiofrequency pulse, where the effect of the pulse depends on the orientation of the individual crystallites. Copyright © 2016 Elsevier Inc. All rights reserved.

Infrastructures for spin-off companies

NARCIS (Netherlands)

van der Sijde, Peter; Ridder, Annemarie; Gómez, J.M.; Pastor, J.T.; Galiana, D.; Mira, I.

2002-01-01

The objective of the book is to bring together the leading university spin-off programmes in Europe and to offer these as best practice to a target group of "newcomers" in this business.In total 19 contributions presenting their experience, their best practice focused on the specific mechanisms and

Public acceptance of fusion energy and scientific feasibility of a fusion reactor. Spin-off effects of fusion research and development

International Nuclear Information System (INIS)

Morino, Nobuyuki; Ogawa, Yuichi

1998-01-01

It is observed that new and sophisticated technologies developed through research and development in relation to magnetic confinement fusion have been transferred to other industrial and scientific fields with remarkable spin-off effects. Approximately 10 years ago, the Japan Atomic Industrial Forum (JAIF) has investigated technical transfer and spin-off effects of fusion technologies developed in Japan. The essence of the results of this investigation as well as high technologies developed in the last decade, some of which are in the early stage of technical spin-off, are described. It is additionally explained that independent technical development conducted by our country as well as by engineers themselves is important in achieving effective spin-off. An outline of scientific spin-off effects is also described, including utilization technologies of fusion reactions besides those for energy production purposes, the progress of scientific understanding in the course of fusion research, and scientific information transfer and communication with other fields. (author)

Commercializing science by means of university spin-offs : an ethical review

NARCIS (Netherlands)

Burg, van J.C.

2010-01-01

This paper reviews, structures and evaluates the moral issues generated by efforts to commercialize university research by means of university spin-offs. University spin-offs are new ventures founded to exploit university research. First, I review the advantages and disadvantages of

Technologic spin-off from CNEA's activities

International Nuclear Information System (INIS)

Belinco, Cesar G.

2001-01-01

An analysis is made of the spin-off of technology from the nuclear activities in Argentina. Several examples are mentioned in fields such as material sciences, non-destructive testing, forensic research, space activities, instrumentation as well as in environmental studies

Longitudinal Double Spin Asymmetry in Inclusive π0 Production at Forward Rapidities in √s=62.4 GeV Polarized p+p Collisions at RHIC

International Nuclear Information System (INIS)

Kazantsev, Andrey

2007-01-01

The gluons' Gluons spin contribution to proton spin is an important the key aspect for understanding the proton spin structure. It can be probed by the double helicity asymmetry of π0 production in polarized p+p collisions. During the longitudinally polarized proton run in 2006 PHENIX collected substantial data at √s=62.4 GeV and √s=200 GeV. In 2006 PHENIX commissioned a new electromagnetic calorimeter, the Muon Piston Calorimeter (MPC), located in the forward rapidity rapidities region. This calorimeter allows to significantly improves the PHENIX acceptance. In this report the MPC feasibility of the MPC for longitudinal double spin asymmetry studies is discussed

Spin-off Growth and Job Creation: Empirical Evidence on Denmark

DEFF Research Database (Denmark)

Gjerløv-Juel, Pernille; Dahl, Michael S.

Employment is often the primary motivation behind entrepreneurial and industrial policy. But, new firms are known to differ greatly in performance. Not everyone survives and fewer achieve high growth rates. It is established that spin-offs - firms founded by employees from incumbent firms...... a comprehensive dataset covering all entrants in the Danish economy from 1995 to 2004, this paper investigates how spin-off job creation differs from that of other entrants in terms of growth rates, variation and sustainability. We find that spin-offs are not only surviving longer, as the existing literature...... suggests, they also constitute a more homogeneous group, show increased stability in growth patterns and not least are they relatively more important for job creation in the economy....

An Examination of Corporate Spin-Offs on Company Performance and Shareholder Value

OpenAIRE

Scicluna, Karl

2015-01-01

The aim of this study is to examine the implications of corporate spin-offs on company performance and shareholder value. The study uses both event study and accounting-based study methodologies to assess the stock price response of parent companies to the announcement of spin-offs, and to analyse the long-run operating performance of spin-offs for both parent and subsidiary companies. The study focuses on UK and US firms between 2001 and 2011. Evidence collected from the ev...

Economic spin-off from CERN

Energy Technology Data Exchange (ETDEWEB)

Anon.

1985-01-15

About ten years ago, a famous study by Helwig Schmied on the economic 'spin-off resulting from CERN contracts revealed that every Swiss franc spent by CERN on high technology had produced about 3.5 francs of new business for the firm involved. This is a useful bonus for a major European Laboratory whose basic objective remains, as always, pure scientific research.

Economic spin-off from CERN

International Nuclear Information System (INIS)

Anon.

1985-01-01

About ten years ago, a famous study by Helwig Schmied on the economic 'spin-off resulting from CERN contracts revealed that every Swiss franc spent by CERN on high technology had produced about 3.5 francs of new business for the firm involved. This is a useful bonus for a major European Laboratory whose basic objective remains, as always, pure scientific research

Where Do Spin-Offs Come From?

DEFF Research Database (Denmark)

Rocha, Vera; Carneiro, Anabela; Varum, Celeste

2015-01-01

not received the attention they deserve. Not only do necessity spin-offs perform an important role in the dynamics of competitive markets, by offering a possible solution for recently displaced individuals, but they also create new jobs and help to prevent the depreciation of workers’ human capital....

Spin-off produced by the fusion research and development

International Nuclear Information System (INIS)

Koizumi, Koichi; Konishi, T.; Tsuji, Hiroshi

2001-03-01

Nuclear fusion devices are constructed by the integration of many frontier technologies and fusion science based on a wide area of science such as physics, electromagnetics, thermodynamics, mechanics, electrical engineering, electronics, material engineering, heat transfer and heat flow, thermal engineering, neutronics, cryogenics, chemical engineering, control engineering, instrumentation engineering, vacuum engineering. For this, the research and development of elementary technology for fusion devices contributes to advance the technology level of each basic field. In addition, the mutual stimulus among various research fields contributes to increase the potential level of whole 'science and technology'. The spin-offs produced by the fusion technology development give much contribution not only to the general industrial technologies such as semiconductor technology, precision machining of large component, but also contribute to the progress of the accelerator technology, application technology of superconductivity, instrumentation and diagnostics, plasma application technology, heat-resistant and heavy radiation-resistant material technology, vacuum technology, and computer simulation technology. The spin-off produced by the fusion technology development expedite the development of frontier technology of other field and give much contribution to the progress of basic science on physics, space science, material science, medical science, communication, and environment. This report describes the current status of the spin-off effects of fusion research and development by focusing on the contribution of technology development for International Thermonuclear Experimental Reactor (ITER) to industrial technology. The possibilities of future application in the future are also included in this report from the view point of researchers working for nuclear fusion development. Although the nuclear fusion research has a characteristic to integrate the frontier technologies of

A Longitudinal Study of the Effects of Innovativeness on Academic Spin-offs Performance

DEFF Research Database (Denmark)

Giones, Ferran; Billström, Anders; Rasmussen, Einar

, between 2000 and 2012, of 125 academic spin-offs of Norway provides valuable insights on how the origin of the technology impact differences in market performance. The results show how specific elements related to the ASOs’ product innovativeness contribute to its market performance. The findings provide......Academic Spin-Offs are given the mission to bring to society science and technology innovations. Nevertheless, the relative weak financial performance of these firms has recently been a focus of discussion. Prior research has explored factors that might explain the performance diversity, including...... aspects related to the academic entrepreneur (e.g. human capital), organizational (e.g. team characteristics, board composition, network of partners) and institutional factors (e.g. university context, support mechanisms). An under studied potential source of heterogeneity is the diversity of technologies...

The Indonesian Islamic Bank’s Spin-off: A Study in Regional Development Banks

Directory of Open Access Journals (Sweden)

Ismawati Haribowo

2016-12-01

Full Text Available The Islamic banking spin-off became a major issue after the establishment of the Act No. 21 of 2008. The problem that arises according to this spin-off is the existence of sharia unit that owned by the regional development banks, which is almost the banks has a small size. This paper is going to evaluate the spin-off criteria are regional development banks, besides that this article is going to analyze the spin-off strategy that can use by sharia unit that owned by the regional development bank. The techniques that employed in this paper are ARIMA, simulation, and descriptive-qualitative. The result shows that there is no sharia unit can achieve the 50% share asset of its parents. There are also several strategies that can be used by the sharia unit. The main thing that should emphasize is the Islamic bank's spin-off is only one of the policies that can be taken to develop the Islamic banking industryDOI: 10.15408/aiq.v9i1.4308 

Spin-off and Innovation in the Pharmaceutical Industry

Directory of Open Access Journals (Sweden)

Enzo Peruffo

2014-11-01

Full Text Available Parent companies usually undertake corporate spin-offs to cope with higher competitive environments or when, in high technology industries, the differences between R&D investments and intangible assets are larger. Consistent with the recent “positive view”, spinoffs can be considered as a “proactive strategic choice” to foster innovation, develop new activities, being different from past strategic initiatives and, more generally, not being strictly connected to the corporate strategy of the firm. In order to investigate the relation between divestiture decisions and innovation, we conduct an explorative case study in the pharmaceutical industry to show how spin-offs can help firms to explore new opportunities for innovation, search for new funding and push to create the basis for future development.

A study on the improvement of spin-off effectiveness of national nuclear R and D activities

International Nuclear Information System (INIS)

Yang, Maeng Ho; Lee, T. J.

1997-02-01

This study consists of two parts. One is to identify factors affecting technological effectiveness of the spin-off process that is defined as the technology transfer process from government sponsored research institutes (GRI's) to the civilian sector. The other is to analyze the environment of the spin-off process and to suggest guidelines for addition, this study also examines spin-off effectiveness with technology transfer types. To validate the conceptual model and hypotheses of the spin-off process, data are collected from 12 cases through in-depth interviews and questionnaires. Spearman correlation analysis is employed in order to test the hypotheses on the spin-off process. (author). 50 refs., 17 tabs., 12 figs

Medals for CERN spin-offs

CERN Multimedia

2007-01-01

Nine companies whose inventions make use of technologies developed at CERN were honoured at the 35th Salon des Inventions, held in Geneva from 18-22 April. CERN was the Salon's guest of honour. The CERN 'table' at the 35th Salon des Inventions. This year's Salon included 1000 exhibitions brought by 775 exhibitors from 45 countries. Those with misgivings about the value of particle physics should take a look at the list of prize winners from the 35th Salon des Inventions, held in Geneva from 18-22 April. Nine of the winning inventions were spin-offs from technologies developed at CERN. CERN's research and development strategy includes a programme where technologies developed at and for the Laboratory are jointly developed with industries, so that they may be adapted into a commercial product for other uses. These include many different domains of applications such as medical imaging and IT. The following companies won awards at the Salon for inventions from CERN-developed technologies: PANalytical won a g...

Survey of methods for rapid spin reversal

International Nuclear Information System (INIS)

McKibben, J.L.

1980-01-01

The need for rapid spin reversal technique in polarization experiments is discussed. The ground-state atomic-beam source equipped with two rf transitions for hydrogen can be reversed rapidly, and is now in use on several accelerators. It is the optimum choice provided the accelerator can accept H + ions. At present all rapid reversal experiments using H - ions are done with Lamb-shift sources; however, this is not a unique choice. Three methods for the reversal of the spin of the atomic beam within the Lamb-shift source are discussed in order of development. Coherent intensity and perhaps focus modulation seem to be the biggest problems in both types of sources. Methods for reducing these modulations in the Lamb-shift source are discussed. The same Lamb-shift apparatus is easily modified to provide information on the atomic physics of quenching of the 2S/sub 1/2/ states versus spin orientation, and this is also discussed. 2 figures

Open Innovation Practice: A Case Study of University Spin-Offs

Directory of Open Access Journals (Sweden)

Yuliya Shutyak

2016-01-01

Full Text Available The paper investigates the practice of Open Innovation (OI of university spin-offs. Three interviews were conducted to discuss the knowledge of spin-offs about OI, their attitude to this innovation management strategy based on perceived advantages and disadvantages, and their motivation towards OI practice in the future. Problems with planning, control and trust appear to be some of the most important for OI success. Focusing on these and other urgent aspects of OI, the article discusses a research agenda that can help in formulating research questions and hypothesis, thus directing their efforts to search for solutions to identified problems

Firm Spin-offs in Denmark, 1981-2000

DEFF Research Database (Denmark)

Eriksson, Tor Viking; Kuhn, Johan Moritz

Abstract. The motivation of this paper is to add large sample evidence to our knowledge on the extent to which the likelihood of business failure or success is related to relationships between parent firms and their 'off-spring'. For this purpose we make use of an exhaustive matched employer...... that the exit risks of spin-offs and the comparison group are converging over time. However, when we cater for unobserved heterogeneity this observation turns out to be predominantly an outcome of selection rather than the result of other start-ups catching up via some learning process. For the entire sample...

Entrepreneurial Networks of University Spin-offs : How Social Networks Affect the Growth of Firms

NARCIS (Netherlands)

Soetanto, D.P.

2009-01-01

Knowledge can be valorized in many different ways. University spin-offs have proven to be very effective as the knowledge generated in a university or research institute is directly translated into commercial activities. In addition, university spin-offs have played an important role in the economic

Global Landslides on Rapidly Spinning Spheroids

Science.gov (United States)

Scheeres, Daniel J.; Sanchez, P.

2013-10-01

The angle of repose and conditions for global landslides on the surfaces of small, rapidly spinning, spheroidal asteroids are studied. Applying techniques of soil mechanics, we develop a theory for, and examples of, how regolith will fail and flow in this microgravity environment. Our motivation is to develop an understanding of the "top-shaped" class of asteroids based on analytical soil mechanics. Our analysis transforms the entire asteroid surface into a local frame where we can model it as a conventional granular pile with a surface slope, acceleration and height variations as a function of the body's spin rate, shape and density. A general finding is that the lowest point on a rapidly spinning spheroid is at the equator with the effective height of surface material monotonically increasing towards the polar regions, where the height can be larger than the physical radius of the body. We study the failure conditions of both cohesionless and cohesive regolith, and develop specific predictions of the surface profile as a function of the regolith angle of friction and the maximum spin rate experienced by the body. The theory also provides simple guidelines on what the shape may look like, although we do not analyze gravitationally self-consistent evolution of the body shape. The theory is tested with soft-sphere discrete element method granular mechanics simulations to better understand the dynamical aspects of global asteroid landslides. We find significant differences between failure conditions for cohesive and cohesionless regolith. In the case of cohesive regolith, we show that extremely small values of strength (much less than that found in lunar regolith) can stabilize a surface even at very rapid spin rates. Cohesionless surfaces, as expected, fail whenever their surface slopes exceed the angle of friction. Based on our analysis we propose that global landslides and the flow of material towards the equator on spheroidal bodies are precipitated by exogenous

The Effects of Innovativeness on Academic Spin-offs Performance

DEFF Research Database (Denmark)

Giones, Ferran; Billström, Anders; Rasmussen, Einar

Academic Spin-Offs (ASOs) are born with the mission to bring to market science and technology innovations. Nevertheless, their relative weak financial performance has been a focus of discussion. Prior research has explored factors that explain part of the performance diversity, including aspects...... source of performance heterogeneity. Academic spin-offs transition from a research to a market context is complex. The technology novelty in ASOs generates a staged challenge for the academic entrepreneur. First, identifying a market and activating the first sale; second, generating a sustainable revenue...... stream that brings growth to the ASO. However, we have still a limited knowledge on the relationship between technology innovativeness and firm performance in the ASOs context. This study tests the relationship between innovativeness dimensions, across different industries, and the observed firm (ASOs...

Infrastructures for University Spin-off Programs: an introduction

NARCIS (Netherlands)

van der Sijde, Peter; Ridder, Annemarie; van der Sijde, P.C.; Ridder, A.; Gómez, J.M.; Pastor, J.T.; Galiana, D.; Mira, I.

2002-01-01

The objective of the book is to bring together the leading university spin-off programmes in Europe and to offer these as best practice to a target group of "newcomers" in this business.In total 19 contributions presenting their experience, their best practice focused on the specific mechanisms and

What Explains the Survival Gap of Pushed and Pulled Corporate Spin-offs?

DEFF Research Database (Denmark)

Rocha, Vera; Carneiro, Anabela; Varum, Celeste

2015-01-01

Unconditionally, pushed spin-offs are found to survive longer than their pulled counterparts. Using matched employer-employee data and novel multivariate decomposition techniques, we show that pushed spin-offs’ relative survival advantage is mostly explained by their larger human capital endowments...

Academic Spin-off as Triple Helix Element: Case-Study of Russian Regions

Directory of Open Access Journals (Sweden)

Konstantin Ivanovich Grasmik

2016-10-01

Full Text Available The innovation process is becoming more open. According to the concept of the Triple Helix, this requires the creation of institutions capable of mediating the interaction of agents, primarily related to the different elements of the innovation system. The academic spin-off is not only a form of technology transfer, set up at the university but also the institution that provides the interaction of scientists and entrepreneurs. This article gives an analysis of the implementation of the program of creating academic spin-offs in Russia. The main focus of the study is to analyze the affiliation of university spin-off with other companies, including personal links of founders. Research reveals that linkages are substantially personal: University staff member at the same time could be an entrepreneur. This finding allows not only clarifying the concept of the Triple Helix but also increasing the effectiveness of innovation policy, focusing on employees who can combine science and entrepreneurship.

El Spin-Off como Elemento Emprendedor y Dinamizador de la Red Empresarial

Directory of Open Access Journals (Sweden)

José Manuel Comeche Martínez

2013-01-01

Full Text Available El objetivo de este artículo es estudiar el sistema formado por las relaciones que se establecen entre los distintos participantes de una red y cómo su incidencia favorece la creación de empresas, concretamente en el proceso de constitución de un Spin-Off . El resultado obtenido de este análisis, basado en el método del caso, muestra que la estrategia sustentada en el Spin-Off se convierte en un instrumento válido para la creación y desarrollo de las empresas, ya que incorpora las ventajas financieras que este tipo de acuerdo proporciona y, por otra parte, permite reducir los niveles de riesgo de todo nuevo proyecto al partir desde una situación con menores niveles de incertidumbre. ABSTRACTThis article aims to study the system formed by relationships established among the different participants in a network and how its weight favors business creation, specifically in the founding of a Spin Off.The results obtained based in the case study method show that a strategy based on Spin Off is a valid option to create and develop enterprises, since it incorporates the financial advantage that this type of agreement produces, and in the other hand allows to reduce the risk level associated with any new project by creating it from a position of a lesser level of uncertainty.

A business strategy formulation for commercializing university-created technology: A university spin-offs

Science.gov (United States)

Saputra, Iqbal Wahyu; Sutopo, Wahyudi; Zakaria, Roni

2018-02-01

There are some mechanism to commercialize the innovations that have been developed by academic scientists in universities, i.e. patenting, licensing, start-up creation, and university-industry partnerships. The start-up creations or university spin-offs (USOs) company is a very special start-up company that is founded by an academic inventor and the university with the aim to commercialize the technological innovation that created by the university. However, it is not always as smooth as expected. The market competitiveness of the USOs obviously has many challenges to be able to compete with the existing companies, analysis need to be done to get the right business step so the business strategy will be efficient. In this article, we discuss a real case study of a university spin-off that owned by Sebelas Maret University for Commercializing Battery Lithium. The aim of our research is twofold: first, to identify the gap in the literature of business strategy formulation between a conventional and USOs. Second, to propose a business strategy formulation for commercializing university-created technology, i.e. battery lithium as core business of a university spin-off as a case study. We conduct surveys, observation and FGD in order to collect the data and information to build the company objective and goals. The analytical tools to generate the solution of business strategy are SWOT analysis, IFE-EFE matrix, and QSPM model so the result will be the most attractive and suitable for the company. The result shows that the case study of USO company is classified on conservative continuous improvement phase so the suitable strategy for this company are product development and business strategy integration.

Spin-off and market share in the Indonesian Islamic banking industry: a difference in difference analysis

Directory of Open Access Journals (Sweden)

Al Arif M. Nur Rianto

2017-12-01

Full Text Available According to The Act No. 21 of 2008 concerning Islamic Banking in Indonesia, the conventional banks are obligated to spun-off their Islamic business units after achieving a certain set of requirements. The spin-off requirements are: (i reach 50% market share asset of its parents; or (ii 15 years after the implementation of the Islamic Banking Act. This study emphasizes the impact of Islamic banks' spin-off on market share. The method used in this study is a difference in difference analysis. This technique is a quasi-experiment separate into two groups, such as the treatment groups (four spin-offs' banks and control group (two fullfledged Islamic banks. This study used quarterly data from 2005 until 2016. The results show that, first, there is a difference in the Islamic banks' market share between pre- and post-spinoff. Second, there is a difference in the market share of spin-offs' banks between pre- and postspin- off. Third, there are there external factors that can affect the Islamic banks' market share, i.e., inflation rate, interest rate, and economic growth rate. The paper is a useful source of information that may provide relevant guidelines in helping the future development of spin-off activity in Islamic banking industry. The finding could be helpful for policymakers to create a supporting strategy to accelerate the development of Islamic banking industry. This result also could be of use for Islamic banking industries in other countries.

mplementación de Spin Off en el área de informática en Colombia

Directory of Open Access Journals (Sweden)

Ricardo Botero

2014-12-01

Full Text Available Spin off se denomina al modelo de negocios para la creación de nuevas empresas con alto componente investigativo. Este tipo de proyectos tiene una orientación metodológica basada en la creación de empresas que buscan explotar los recursos tecnológicos y de investigación, sean de software o de hardware, con miras en obtener resultados económicos e incursionar en la actividad mercantil. El spin off surge del modelo de triple hélice, en donde la universidad es la generadora del conocimiento, la empresa es el lugar de producción y el estado garantiza la estabilidad, el intercambio y la financiación de la investigación. La creación de las Spin Off ha surgido a medida que han cambiado los intereses tanto de las universidades como del estado en su modelo de triple hélice. En el entorno colombiano esas entidades están representadas por Colciencias y el gobierno nacional con las políticas en ciencia tecnología e innovación. En Colombia la creación e implementación de Spin Off todavía está en su fase de exploración, en donde se incluye la creación de algunas Spin off en diferentes áreas. La primera Spin Off universitaria en el país, denominada empresa de Conocimiento y servicios de Ingeniería S.A.S. (Conoser, surgió en la Universidad de Antioquia.

Canadian experience with spin-offs from nuclear technology

International Nuclear Information System (INIS)

Lennox, C.G.; Garvey, P.M.

1989-01-01

The innovation process introduced into AECL's research laboratories is described, with its achievements in increased commercial and spin-off businesses. In particular, the role of the champion or entrepreneur is emphasized in the manner in which he/she interacts within a dedicated team to pursue each opportunity. Examples are provided of several commercial and business development opportunities resulting from the background research programs

LA TRANSFERENCIA DE INVESTIGACIÓN EN INSTITUCIONES DE EDUCACIÓN SUPERIOR MEDIANTE SPIN-OFF

Directory of Open Access Journals (Sweden)

Mauricio Castillo-Vergara

2015-01-01

Full Text Available Este ensayo tiene como objetivo el análisis de la situación actual respecto al concepto de Spin-Off en Chile como mecanismo que las universidades pueden utilizar para transferir resultados de la investigación pública en el sistema económico. Si bien, se reconoce la importancia en cuanto a la innovación y el emprendimiento, para el desarrollo de universidades emprendedoras, las Spin-Offs no han sido estimuladas desde las universidades. El ensayo se centra en contextualizar el desarrollo de Spin-Off en otros países de Norteamérica y Europa y enfatizar los factores que han permitido su nacimiento, crecimiento y principales resultados en dichas naciones. Su objetivo principal es identificar y proporcionar orientaciones para estimular el desarrollo de Spin-Off universitarias en el país. Se concluye que los modelos de negocio son importantes para comercializar los resultados de investigación, así como el papel que juega el equipo investigador, debiendo considerarse estrategias para fomentar las capacidades propias de este equipo, más allá del perfil técnico. Chile, tiene una gran oportunidad de liderar el desarrollo de esta línea de crecimiento en Latinoamérica, tomando como experiencia los casos internacionales.

Strategic drivers for oil business model: vertical integration versus spin-off; Direcionadores estrategicos para o modelo de negocios petroliferos: integracao vertical versus spin-off

Energy Technology Data Exchange (ETDEWEB)

Araujo, Gregorio da Cruz; Szpigel, Pedro [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

2012-07-01

The recent spin-offs of Marathon (2011) and ConocoPhillips (2012), as well as other breakups between the upstream and downstream segments announced by the smaller oil companies during the past year, raised questions about one of the main and oldest paradigms of oil industry: the vertical integration. Corporate spin-off is not a new phenomenon in the industry in general, but only very recently has got prominence in the oil industry. The objective of this paper is to analyze the factors that motivate corporate restructuring in the oil industry, leading to strategic decisions that strengthen the vertical integration or that lead to break the value chain. The key point is whether there will be contagion among majors due to the movement of CononoPhillips, starting a new trend in the industry, or whether the restructuring already done will be only restricted to the specific needs of certain oil companies. (author)

Rapid characterizing of ferromagnetic materials using spin rectification

International Nuclear Information System (INIS)

Fan, Xiaolong; Wang, Wei; Wang, Yutian; Zhou, Hengan; Rao, Jinwei; Zhao, Xiaobing; Gao, Cunxu; Xue, Desheng; Gui, Y. S.; Hu, C.-M.

2014-01-01

Spin rectification is a powerful tool for dc electric detections of spin dynamics and electromagnetic waves. Technically, elaborately designed on-chip microwave devices are needed in order to realize that effect. In this letter, we propose a rapid characterizing approach based on spin rectification. By directly sending dynamic current into ferromagnetic films with stripe shape, resonant dc voltages can be detected along the longitudinal or transversal directions. As an example, Fe (010) films with precise crystalline structure and magnetic parameters were used to testify the reliability of such method. We investigated not only the dynamic parameters and the precise anisotropy constants of the Fe crystals but also the principle of spin rectification in this method

The impact of university-based incubation support on the innovation strategy of academic spin-offs

OpenAIRE

Soetanto, Danny Prabowo; Jack, Sarah Louise

2016-01-01

This paper develops understanding about how incubation support and innovation strategy can determine the performance of academic spin-offs. Using a sample of spin-offs from the United Kingdom, the Netherlands and Norway, we analyse the potential moderating effect of incubation support (networking and entrepreneurial support) on innovation strategy effectiveness. The empirical results demonstrate: (1) a technology and market exploitation strategy has a stronger and more positive effect on the ...

Opportunity recognition and international new venture creation in University spin-offs

DEFF Research Database (Denmark)

Hannibal, Martin; Evers, Natasha; Servais, Per

2016-01-01

Extant research suggests that the founder’s activities and interactions are considered pivotal in driving the opportunity recognition process leading to international new venture emergence. This paper aims to explore the opportunity recognition process and international new venture emergence...... in the context of university high-technology spin-offs that are internationally market driven from inception. University spin-offs (USOs) are defined as ‘new firms created to exploit commercially some knowledge, technology or research results developed within a university’ (Pirnay et al., Small Bus Econ 21...... that the inventor-founders are typically engaged in opportunity recognition processes that are characterized as creative, driven by scientific innovations. It is indicated that the process of USO emergence and continuous development involves activities and interactions similar to typical international new ventures...

La ricerca universitaria per l’innovazione applicata al territorio: SI2G, spin off universitario

Directory of Open Access Journals (Sweden)

Primo Zingaretti

2009-03-01

Full Text Available SI2G, university spin-offSI2G is a spin-off company of Polytechnic University of Marche, built up in 2008 by a cross-curricular team belonging to the Engineer faculty. SI2G goes into business as ICT service and solution provider ranging from Remote Sensing and landscape monitoring (in particular Land Cover/Land Use mapping to up-to-date computer cartography, Web-GIS solutions and Geographic Information Systems.

The Effect of Executive Migration and Spin-offs on Incumbent Firms

DEFF Research Database (Denmark)

Gjerløv-Juel, Pernille; Dahl, Michael S.

If spin-offs are founded on intellectual capital accumulated at the parent firms, they could be potentially harmful to those firms. However, similar effects on parent firms’ performance could be expected for executive migration to rivals. Exploiting a comprehensive Danish linked employer-employee...

The Sources of Competitive Advantage in University Spin-Offs: a Case Study

Directory of Open Access Journals (Sweden)

Marco Greco

2013-09-01

Full Text Available University Spin-Offs are incorporated to exploit the knowledge and skills achieved within Universities. Often, their competitive advantage is represented by specific know-how that may be hardly imitated by competitors. In this article we present an analysis of the intellectual capital assets owned by a University Spin-Off using a framework recently introduced in literature. The framework resorts to a series of structured interviews to key figures within the organization. The interviews are synthesized through the Analytic Network Process and the results are compared using graphical and cost/ benefit analyses. The implementation of the framework creates a useful panel for the planning of investments in intellectual capital assets in order to create value. Moreover, it may emphasize possible discrepancies among interviewees about the importance of each intellectual capital asset.

Use of rapid-scan EPR to improve detection sensitivity for spin-trapped radicals.

Science.gov (United States)

Mitchell, Deborah G; Rosen, Gerald M; Tseitlin, Mark; Symmes, Breanna; Eaton, Sandra S; Eaton, Gareth R

2013-07-16

The short lifetime of superoxide and the low rates of formation expected in vivo make detection by standard continuous wave (CW) electron paramagnetic resonance (EPR) challenging. The new rapid-scan EPR method offers improved sensitivity for these types of samples. In rapid-scan EPR, the magnetic field is scanned through resonance in a time that is short relative to electron spin relaxation times, and data are processed to obtain the absorption spectrum. To validate the application of rapid-scan EPR to spin trapping, superoxide was generated by the reaction of xanthine oxidase and hypoxanthine with rates of 0.1-6.0 μM/min and trapped with 5-tert-butoxycarbonyl-5-methyl-1-pyrroline-N-oxide (BMPO). Spin trapping with BMPO to form the BMPO-OOH adduct converts the very short-lived superoxide radical into a more stable spin adduct. There is good agreement between the hyperfine splitting parameters obtained for BMPO-OOH by CW and rapid-scan EPR. For the same signal acquisition time, the signal/noise ratio is >40 times higher for rapid-scan than for CW EPR. Rapid-scan EPR can detect superoxide produced by Enterococcus faecalis at rates that are too low for detection by CW EPR. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Scientific Team Effectiveness and the External CEO: A Study of Biotechnology University Spin-Offs

Science.gov (United States)

van der Steen, Marianne; Englis, Paula Danskin; Englis, Basil G.

2013-01-01

This paper presents an empirical exploration of the effectiveness of scientific teams and the role of an external CEO in the spin-off formation process. The paper contributes to the literature by focusing on the role of the experienced or "external" entrepreneur (their commercial resources and capabilities) in the early phase of spin-off…

Off-shell superconformal higher spin multiplets in four dimensions

Science.gov (United States)

Kuzenko, Sergei M.; Manvelyan, Ruben; Theisen, Stefan

2017-07-01

We formulate off-shell N = 1 superconformal higher spin multiplets in four spacetime dimensions and briefly discuss their coupling to conformal supergravity. As an example, we explicitly work out the coupling of the superconformal gravitino multiplet to conformal supergravity. The corresponding action is super-Weyl invariant for arbitrary supergravity backgrounds. However, it is gauge invariant only if the supersymmetric Bach tensor vanishes. This is similar to linearised conformal supergravity in curved background.

Charge-odd and single-spin effects in two pion production in ep bar collisions

International Nuclear Information System (INIS)

Galynskij, M.V.; Kuraev, E.A.; Shajkhatdenov, B.G.; Ratcliffe, P.G.

2000-01-01

We consider two-photon and Bremsstrahlung mechanisms for the production of two charged pions in high-energy electron (proton) scattering off a transversely polarised proton. Interference between the relevant amplitudes generates a charge-odd contribution to the cross section for the process. In a kinematics with a jet moving along electron spin-independent part may be used for determination of phase differences for pion-pion scattering in the states with orbital momentum 0 or 2 and 1 whereas in a kinematics with a jet moving along proton spin-dependent part may be used to explain the experimental data for single-spin correlations in the production of negatively charged pions. We also discuss the backgrounds and estimate the accuracy of the results at less than 10% level. In addition simplified formulae derived for specific kinematics, with small total transverse pion momentum, are given

Spin-resolved unpolarized neutron off-specular scattering for magnetic multilayer studies

CERN Document Server

Lauter, H J; Toperverg, B P; Romashev, L; Ustinov, V; Kravtsov, E; Vorobiev, A; Major, J; Nikonov, O A

2002-01-01

The capabilities of the method of using unpolarized neutron off-specular scattering for investigation of magnetic structures in exchange-coupled magnetic multilayers are thoroughly examined. It is demonstrated that strong anomalies in spin-flip selective scattering processes originating from magnetic fluctuations enables a straightforward determination of the coupling angle between the magnetization direction of successive Fe layers in Fe/Cr multilayers. A complete quantitative 2-dimensional data analysis of specular and off-specular scattering has been employed to provide detailed information on the lateral and transverse magnetization arrangement in the multilayer. (orig.)

Learning networks of academic spin-offs - A spatial perspective

OpenAIRE

Mozhdeh Taheri; Marina Van Geenhuizen

2011-01-01

The importance of new knowledge in innovative activities of firms and the impact of these activities on economic development of regions have been acknowledged in many studies. In particular, universities and firms that are established on university knowledge, spin-off firms, function as nodes and channels through which new knowledge is diffused into the wider (regional) economy. New knowledge is a strategic resource of competitive advantage for young high-tech firms. Of course, many of these ...

Enacted identities in the university spin-off process - bridging an imaginative gap

DEFF Research Database (Denmark)

Hannibal, Martin

2017-01-01

This paper employs a case study to explore the interdependencies between enacted role identities and behavioural logics of eight inventor-founders embedded in university spin-off venturing. The major tendencies in the findings suggest that the inventor-founders enact their academic role identity ...

MOTIVATION AND SUCCESS OF ACADEMIC SPIN-OFFS: EVIDENCE FROM HUNGARY

Directory of Open Access Journals (Sweden)

Novotny Adam

2014-07-01

Full Text Available Universities today are expected to play a major role in contributing to economic competitiveness and especially through the process of commercializing research results. There is much evidence that firms started by university researchers are effective channels of knowledge from the academic sphere to the private sector. To encourage the creation of university spin-offs, first we have to understand the goals and motivations of academic entrepreneurs. This paper includes the empirical study of 80 Hungarian spin-off owners, who run their own firm besides retaining their position at the university. The purpose is to explore the motives that drive academics to start their own business and to test the relationship between motivations and entrepreneurial success. Success is measured from both objective and subjective aspects. The former refers to quantitative indices related to business performance such as firm revenue, change of revenue, number of employees and firm age. The latter refers to the self-evaluation of one’s success as an academic entrepreneur. Subjective success is measured on the one hand by the researcher’s own entrepreneurial success criteria, while on the other hand by the perceived degree to which his or her knowledge has been commercialized on the market. The results show that the dissatisfaction with the university salary (necessity is the most important motive for starting a venture in the academic sphere. The studied entrepreneurial motivations, except for necessity, have a significant relationship with subjective success, but a weaker or no relationship with objective success. The results also highlight the importance of research-related motives, which have a relatively strong link with subjective success (mainly with the subjective success of technology transfer, and are also related to some objective performance indicators of the venture such as revenue. Although the need for achievement and the need for independence are

How academic entrepreneurship meets the university: university spin-offs in stakeholder networks

NARCIS (Netherlands)

Rasmussen, Einar; Benneworth, Paul Stephen; Gulbrandsen, Magnus

2015-01-01

Some universities and departments have been very successful in stimulating university spin-off firms (USOs). It remains an open question whether this is due to unique abilities and circumstances or if it can be stimulated at many universities. This paper seeks to discuss this question by integrating

Spin-Offs: Analysis of a Set of Situations in Light of Mintzberg´S 5 P´S Model (1987

Directory of Open Access Journals (Sweden)

Roberto Minadeo

2013-12-01

Full Text Available Literature often discusses matters concerning mergers and acquisitions. On the other hand, from an academic standpoint, spin-offs dwell in limbo as a poorly explored subject matter. Nevertheless, spin-off operations are a commonplace and serve multiple purposes including operational, legal, tax, litigation, and market amongst other, aspects. Ground on this perspective, this study sought to analyse the motivations driving a considerable number of spin-off operations – 60 in all – selected as of the 1930´s yet placing greater emphasis on those that took place as of 1990. Secondary data was researched, categorized and analysed by the author in light of Mintzberg’s 5 P´s model (1987, namely: a plan – in the sense defining a future course of action; b ploy, or maneuver to outsmart competition under given circumstances; c position – in the sense of the patterns, standing and scope conquered within a given market; d the company´s perspective when facing the market; e pretext – a move or maneuver to face competition. Findings revealed that most spin-offs do fit, in descending order, into pretext, plan, position, pattern and finally, perspective frameworks. 

Analytic Models for Sunlight Charging of a Rapidly Spinning Satellite

National Research Council Canada - National Science Library

Tautz, Maurice

2003-01-01

... photoelectrons can be blocked by local potential barriers. In this report, we discuss two analytic models for sunlight charging of a rapidly spinning spherical satellite, both of which are based on blocked photoelectron currents...

Selective One-Dimensional Total Correlation Spectroscopy Nuclear Magnetic Resonance Experiments for a Rapid Identification of Minor Components in the Lipid Fraction of Milk and Dairy Products: Toward Spin Chromatography?

Science.gov (United States)

Papaemmanouil, Christina; Tsiafoulis, Constantinos G; Alivertis, Dimitrios; Tzamaloukas, Ouranios; Miltiadou, Despoina; Tzakos, Andreas G; Gerothanassis, Ioannis P

2015-06-10

We report a rapid, direct, and unequivocal spin-chromatographic separation and identification of minor components in the lipid fraction of milk and common dairy products with the use of selective one-dimensional (1D) total correlation spectroscopy (TOCSY) nuclear magnetic resonance (NMR) experiments. The method allows for the complete backbone spin-coupling network to be elucidated even in strongly overlapped regions and in the presence of major components from 4 × 10(2) to 3 × 10(3) stronger NMR signal intensities. The proposed spin-chromatography method does not require any derivatization steps for the lipid fraction, is selective with excellent resolution, is sensitive with quantitation capability, and compares favorably to two-dimensional (2D) TOCSY and gas chromatography-mass spectrometry (GC-MS) methods of analysis. The results of the present study demonstrated that the 1D TOCSY NMR spin-chromatography method can become a procedure of primary interest in food analysis and generally in complex mixture analysis.

An enhancement of spin polarization by multiphoton pumping in semiconductors

Energy Technology Data Exchange (ETDEWEB)

Miah, M. Idrish, E-mail: m.miah@griffith.edu.au [Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, Brisbane, QLD 4111 (Australia); Department of Physics, University of Chittagong, Chittagong 4331 (Bangladesh)

2011-08-15

Highlights: {yields} Multiphoton pumping and spin generation in semiconductors. {yields} Optical selection rules for inter-band transitions. {yields} Calculations of spin polarization using band-energy model and the second order perturbation theory. {yields} Enhancement of the electronic spin polarization. - Abstract: A pump-probe spectroscopic study has been carried out in zinc-blende bulk semiconductors. In the semiconductor samples, a spin-polarized carrier population is produced by the absorption of a monochromatic circularly polarized light beam with two-photon energy above the direct band gap in bulk semiconductors. The production of a carrier population with a net spin is a consequence of the optical selection rules for the heavy-hole and light-hole valence-to-conduction band transitions. This production is probed by the spin-dependent transmission of the samples in the time domain. The spin polarization of the conduction-band-electrons in dependences of delay of the probe beam as well as of pumping photon energy is estimated. The spin polarization is found to depolarize rapidly for pumping energy larger than the energy gap of the split-off band to the conduction band. From the polarization decays, the spin relaxation times are also estimated. Compared to one-photon pumping, the results, however, show that an enhancement of the spin-polarization is achieved by multiphoton excitation of the samples. The experimental results are compared with those obtained in calculations using second order perturbation theory of the spin transport model. A good agreement between experiment and theory is obtained. The observed results are discussed in details.

An enhancement of spin polarization by multiphoton pumping in semiconductors

International Nuclear Information System (INIS)

Miah, M. Idrish

2011-01-01

Highlights: → Multiphoton pumping and spin generation in semiconductors. → Optical selection rules for inter-band transitions. → Calculations of spin polarization using band-energy model and the second order perturbation theory. → Enhancement of the electronic spin polarization. - Abstract: A pump-probe spectroscopic study has been carried out in zinc-blende bulk semiconductors. In the semiconductor samples, a spin-polarized carrier population is produced by the absorption of a monochromatic circularly polarized light beam with two-photon energy above the direct band gap in bulk semiconductors. The production of a carrier population with a net spin is a consequence of the optical selection rules for the heavy-hole and light-hole valence-to-conduction band transitions. This production is probed by the spin-dependent transmission of the samples in the time domain. The spin polarization of the conduction-band-electrons in dependences of delay of the probe beam as well as of pumping photon energy is estimated. The spin polarization is found to depolarize rapidly for pumping energy larger than the energy gap of the split-off band to the conduction band. From the polarization decays, the spin relaxation times are also estimated. Compared to one-photon pumping, the results, however, show that an enhancement of the spin-polarization is achieved by multiphoton excitation of the samples. The experimental results are compared with those obtained in calculations using second order perturbation theory of the spin transport model. A good agreement between experiment and theory is obtained. The observed results are discussed in details.

Comparison of continuous wave, spin echo, and rapid scan EPR of irradiated fused quartz

International Nuclear Information System (INIS)

Mitchell, Deborah G.; Quine, Richard W.; Tseitlin, Mark; Meyer, Virginia; Eaton, Sandra S.; Eaton, Gareth R.

2011-01-01

The E' defect in irradiated fused quartz has spin lattice relaxation times (T 1 ) about 100-300 μs and spin-spin relaxation times (T 2 ) up to about 200 μs, depending on the concentration of defects and other species in the sample. These long relaxation times make it difficult to record an unsaturated continuous wave (CW) electron paramagnetic resonance (EPR) signal that is free of passage effects. Signals measured at X-band (∼9.5 GHz) by three EPR methods: conventional slow-scan field-modulated EPR, rapid scan EPR, and pulsed EPR, were compared. To acquire spectra with comparable signal-to-noise, both pulsed and rapid scan EPR require less time than conventional CW EPR. Rapid scan spectroscopy does not require the high power amplifiers that are needed for pulsed EPR. The pulsed spectra, and rapid scan spectra obtained by deconvolution of the experimental data, are free of passage effects.

Off-centre dynamic Jahn-Teller effect studied by electron spin relaxation of Cu2+ ions in SrF2 crystal

International Nuclear Information System (INIS)

Hoffmann, S.K.

2000-01-01

Temperature cw-EPR and pulsed EPR electron spin echo experiments were performed for a low concentration of Cu 2+ ions in cubic SrF 2 crystals. The well resolved EPR spectrum at low temperatures (below 30 K) with parameters g parallel = 2.493, g perpendicular = 2.083, A parallel = 121, A perpendicular = 8.7, A parallel ( 19 F) = 135, A parallel ( 19 F) = 33.0 (A-values in 10 -4 cm -1 ) is transformed continuously into a single broad line above 225 K on heating, due to the g-factor shift and EPR line broadening. These data along with the angular variation EPR data are described in terms of a pseudo-Jahn-Teller effect of (T 2g +A 2u )x(a 1g +e g +t 1u ) type producing six off-centre positions of the Cu 2+ ion in the fluorine cube. Above 30 K a two-step averaging g -factor process occurs and is governed by vibronic dynamics between potential wells of the off-centre positions. This dynamics governs the electron spin relaxation in the whole temperature range. The electron spin-lattice relaxation rate 1/T 1 grows rapidly by six orders of magnitude in the temperature range 30-100 K and is determined by the Orbach-type process with excitations to two excited vibronic levels of energy 83 and 174 cm -1 . For higher temperatures the relaxation is dominated by overbarrier jumps leading to the isotropic EPR spectrum above 225 K. The phase memory time T M has the rigid lattice value 3.5 μs determined by nuclear spectral diffusion and its temperature variation is governed by the vibronic dynamics indicating that the excitations between vibronic levels produce a dephasing of the electron spin precessional motion. (author)

Entanglement property in matrix product spin systems

International Nuclear Information System (INIS)

Zhu Jingmin

2012-01-01

We study the entanglement property in matrix product spin-ring systems systemically by von Neumann entropy. We find that: (i) the Hilbert space dimension of one spin determines the upper limit of the maximal value of the entanglement entropy of one spin, while for multiparticle entanglement entropy, the upper limit of the maximal value depends on the dimension of the representation matrices. Based on the theory, we can realize the maximum of the entanglement entropy of any spin block by choosing the appropriate control parameter values. (ii) When the entanglement entropy of one spin takes its maximal value, the entanglement entropy of an asymptotically large spin block, i.e. the renormalization group fixed point, is not likely to take its maximal value, and so only the entanglement entropy S n of a spin block that varies with size n can fully characterize the spin-ring entanglement feature. Finally, we give the entanglement dynamics, i.e. the Hamiltonian of the matrix product system. (author)

Technologic spin-off from CNEA's activities; Tecnologias derivadas de las actividades de la CNEA

Energy Technology Data Exchange (ETDEWEB)

Belinco, Cesar G [Comision Nacional de Energia Atomica, General San Martin (Argentina). Centro Atomico Constituyentes

2001-07-01

An analysis is made of the spin-off of technology from the nuclear activities in Argentina. Several examples are mentioned in fields such as material sciences, non-destructive testing, forensic research, space activities, instrumentation as well as in environmental studies.

Nurture or nature? The growth paradox of research-based spin-offs

OpenAIRE

Zerbinati, S.; Souitaris, V.; Moray, N.

2012-01-01

This study explores the effect of institutional origin (‘nurture’) and economic context (‘nature’) on the financial resource endowment and subsequent early employment growth of research-based spin-offs (RBSOs). The nurture dimensions capture the relationship between the parent research institution and the RBSO during the start-up phase: the type of incubation model, the formal vs informal transfer of technology and the extent of inventors’ involvement with the firm. The nature dimensions incl...

Star-product functions in higher-spin theory and locality

Energy Technology Data Exchange (ETDEWEB)

Vasiliev, M.A. [I.E. Tamm Department of Theoretical Physics, Lebedev Physical Institute,Leninsky prospect 53, 119991, Moscow (Russian Federation)

2015-06-04

Properties of the functional classes of star-product elements associated with higher-spin gauge fields and gauge parameters are elaborated. Cohomological interpretation of the nonlinear higher-spin equations is given. An algebra ℋ, where solutions of the nonlinear higher-spin equations are valued, is found. A conjecture on the classes of star-product functions underlying (non)local maps and gauge transformations in the nonlinear higher-spin theory is proposed.

Spin-transfer torque magnetoresistive random-access memory technologies for normally off computing (invited)

International Nuclear Information System (INIS)

Ando, K.; Yuasa, S.; Fujita, S.; Ito, J.; Yoda, H.; Suzuki, Y.; Nakatani, Y.; Miyazaki, T.

2014-01-01

Most parts of present computer systems are made of volatile devices, and the power to supply them to avoid information loss causes huge energy losses. We can eliminate this meaningless energy loss by utilizing the non-volatile function of advanced spin-transfer torque magnetoresistive random-access memory (STT-MRAM) technology and create a new type of computer, i.e., normally off computers. Critical tasks to achieve normally off computers are implementations of STT-MRAM technologies in the main memory and low-level cache memories. STT-MRAM technology for applications to the main memory has been successfully developed by using perpendicular STT-MRAMs, and faster STT-MRAM technologies for applications to the cache memory are now being developed. The present status of STT-MRAMs and challenges that remain for normally off computers are discussed

Off-diagonal Bethe ansatz solution of the XXX spin chain with arbitrary boundary conditions

Energy Technology Data Exchange (ETDEWEB)

Cao, Junpeng [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Yang, Wen-Li, E-mail: wlyang@nwu.edu.cn [Institute of Modern Physics, Northwest University, Xian 710069 (China); Shi, Kangjie [Institute of Modern Physics, Northwest University, Xian 710069 (China); Wang, Yupeng, E-mail: yupeng@iphy.ac.cn [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

2013-10-01

Employing the off-diagonal Bethe ansatz method proposed recently by the present authors, we exactly diagonalize the XXX spin chain with arbitrary boundary fields. By constructing a functional relation between the eigenvalues of the transfer matrix and the quantum determinant, the associated T–Q relation and the Bethe ansatz equations are derived.

Off-diagonal Bethe ansatz solution of the XXX spin chain with arbitrary boundary conditions

International Nuclear Information System (INIS)

Cao, Junpeng; Yang, Wen-Li; Shi, Kangjie; Wang, Yupeng

2013-01-01

Employing the off-diagonal Bethe ansatz method proposed recently by the present authors, we exactly diagonalize the XXX spin chain with arbitrary boundary fields. By constructing a functional relation between the eigenvalues of the transfer matrix and the quantum determinant, the associated T–Q relation and the Bethe ansatz equations are derived

Private Venture Capital’s Investment on University Spin-Offs: A Case Study of Tsinghua University Based on Triple Helix Model

DEFF Research Database (Denmark)

Gao, Yuchen; Hu, Yimei; Wang, Jingyi

2015-01-01

and transition economies where governments are transforming their roles. Thus the main purpose of this study is to investigate how private venture capitals’ investment willingness on university spin-offs are influenced by universities and governments under the Chinese context based on the triple helix model....... Through an in-depth case study on the interactions of triple helix actors of Tsinghua University’s spin-offs, it is found that government and university developing an environment of marketization exert positive influences on the investment willingness of private venture capitals. Whilst financial direct...

Optical pumping production of spin polarized hydrogen

International Nuclear Information System (INIS)

Knize, R.J.; Happer, W.; Cecchi, J.L.

1984-01-01

There has been much interest recently in the production of large quantities of spin polarized hydrogen in various fields including controlled fusion, quantum fluids, high energy, and nuclear physics. One promising method for the development of large quantities of spin polarized hydrogen is the utilization of optical pumping with a laser. Optical pumping is a process where photon angular momentum is converted into electron and nuclear spin. The advent of tunable CW dye lasers (approx. 1 watt) allow the production of greater than 10 18 polarized atoms/sec. We have begun a program at Princeton to investigate the physics and technology of using optical pumping to produce large quantities of spin polarized hydrogen. Initial experiments have been done in small closed glass cells. Eventually, a flowing system, open target, or polarized ion source could be constructed

Locational conditions, cooperation, and innovativeness: evidence from research and company spin-offs

OpenAIRE

Lejpras, Anna; Stephan, Andreas

2008-01-01

This paper has two goals. First, it analyzes the extent to which the innovativeness of spin-offs, either born from a research facility or from another company, is influenced by locational conditions. Second, it provides evidence on how important local cooperation links are in comparison to nonlocal ones. Using a sample of approximately 1,500 East German firms from knowledge-intensive sectors, we estimate a structural equation model applying the partial least squares method. We find that proxi...

Negative g-Force Ocular Trauma Caused by a Rapidly Spinning Carousel

Directory of Open Access Journals (Sweden)

Elad Moisseiev

2013-10-01

Full Text Available We present a case of a 10-year-old boy who presented with bilateral diffuse subconjunctival hemorrhages after spinning rapidly on a carousel attached to an electrical scooter. We present his clinical course and discuss the physics and pathophysiology of this unique mechanism of ocular trauma.

Incubators as catalysts of academic spin-offs: evidence from the Israeli case-study

OpenAIRE

Pace Giuseppe

2004-01-01

There is already a respectable body of evidence that connect industrial innovation with knowledge spillovers from academic research, and many suggest that university research units can play a helpful role in small firm innovation, but very few take into account their role in the making of ‘innovation systems’, as promoters of innovative spin-offs. In addition, the theory does not distinguish sufficiently between different patterns that foster the spatial concentration of new activities. Deali...

Board of Directors, Top Management Team and the Developmentof Academic Spin-Off Companies

OpenAIRE

Bjørnåli, Ekaterina S.

2009-01-01

This dissertation addresses the under-studied area of the role of the top management team (TMT) and board of directors in the development of academic spin-off companies (ASOs) originating from public research institutes. ASO research receives growing attention internationally following the rise in commercialization activities in the vast majority of universities. The studies identify the barriers to and facilitators of ASO formation and growth, which are related to faculty attributes and ince...

Determining factors of the effectiveness of IP-based spin-offs: comparing the Netherlands and the US

NARCIS (Netherlands)

Bekkers, R.N.A.; Gilsing, V.A.; Steen, van der M.

2006-01-01

In this paper we describe and analyse IP-based spin-offs as a relatively new phenomenon for transferring knowledge from science to industry. We argue that the effectiveness of this mechanism is subject to a complex array of institutional factors. These factors entail national, sectoral, regional and

Spin effects and the production of heavy baryons in $Z^{0}$ boson decays

CERN Document Server

Saleev, V A

1999-01-01

Predictions are made within the scope of perturbative quantum chromodynamics and the nonrelativistic two-quark baryon model of the magnitude and dependence upon z (the fraction of the momentum of the heavy quark carried off by the baryon) of the longitudinal spin asymmetry parameter A/sub RL/ in the direct creation of Lambda /sub b / and Lambda /sub c/ baryons in the Z/sup 0/-boson channel in the LEP e/sup +/e/sup -/ collider. An estimate is found for the value of A /sub RL/( Lambda /sub b/) in the cascade production of Lambda /sub b/ baryons. (27 refs).

Spin-Label CW Microwave Power Saturation and Rapid Passage with Triangular Non-Adiabatic Rapid Sweep (NARS) and Adiabatic Rapid Passage (ARP) EPR Spectroscopy

Science.gov (United States)

Kittell, Aaron W.; Hyde, James S.

2015-01-01

Non-adiabatic rapid passage (NARS) electron paramagnetic resonance (EPR) spectroscopy was introduced by Kittell, A.W., Camenisch, T.G., Ratke, J.J. Sidabras, J.W., Hyde, J.S., 2011 as a general purpose technique to collect the pure absorption response. The technique has been used to improve sensitivity relative to sinusoidal magnetic field modulation, increase the range of inter-spin distances that can be measured under near physiological conditions, and enhance spectral resolution in copper (II) spectra. In the present work, the method is extended to CW microwave power saturation of spin-labeled T4 Lysozyme (T4L). As in the cited papers, rapid triangular sweep of the polarizing magnetic field was superimposed on slow sweep across the spectrum. Adiabatic rapid passage (ARP) effects were encountered in samples undergoing very slow rotational diffusion as the triangular magnetic field sweep rate was increased. The paper reports results of variation of experimental parameters at the interface of adiabatic and non-adiabatic rapid sweep conditions. Comparison of the forward (up) and reverse (down) triangular sweeps is shown to be a good indicator of the presence of rapid passage effects. Spectral turning points can be distinguished from spectral regions between turning points in two ways: differential microwave power saturation and differential passage effects. Oxygen accessibility data are shown under NARS conditions that appear similar to conventional field modulation data. However, the sensitivity is much higher, permitting, in principle, experiments at substantially lower protein concentrations. Spectral displays were obtained that appear sensitive to rotational diffusion in the range of rotational correlation times of 10−3 to 10−7 s in a manner that is analogous to saturation transfer spectroscopy. PMID:25917132

Self-similarity of proton spin and asymmetry of jet production

International Nuclear Information System (INIS)

Tokarev, M.V.; Zborovsky, I.

2014-01-01

Self-similarity of jet production in polarized p + p collisions is studied. The concept of z-scaling is applied for description of inclusive spectra obtained with different orientations of proton spin. New data on the double longitudinal spin asymmetry, A LL , of jets produced in proton-proton collisions at √s = 200 GeV measured by the STAR Collaboration at RHIC are analyzed in the z-scaling approach. Hypotheses of self-similarity and fractality of internal spin structure are formulated. A possibility to extract information on spin-dependent fractal dimensions of proton from the asymmetry of jet production is justified. The spin-dependent fractal dimensions for the process p-bar+p-bar→jet+X are estimated.

Spin-directed momentum transfers in SIDIS baryon production

International Nuclear Information System (INIS)

Sivers, D.

2016-01-01

The measurement of transverse single-spin asymmetries for baryon production in the target fragmentation region of semi-inclusive deep-inelastic scattering (SIDIS), can produce important insight into those nonperturbative aspects of QCD directly associated with confinement and with the dynamical breaking of chiral symmetry. We discuss here, in terms of spin-directed momentum transfers, the powerful quantum field- theoretical constraints on the spin-orbit dynamics underlying these transverse spin observables. The A τ -odd spin-directed momentum shifts, originating either in the target nucleon (δk TN ) or in the QCD jets (δp TN ) produced in the deep inelastic scattering process, represent significant quantum entanglement effects connecting information from current fragmentation with observables in target fragmentation. (author)

Polarized Emission from Conjugated Polymer Chains Aligned by Epitaxial Growth during Off-Center Spin-Coating

Directory of Open Access Journals (Sweden)

Takuya Anzai

2017-01-01

Full Text Available Due to their macromolecular nature, conjugated polymers can be relatively easily aligned by applying a variety of processes resulting in either elongation or ordering of their conjugated backbones. Processes that induce chain alignment include electrospinning, mechanical rubbing, epitaxial growth, and nanoconfinement and unidirectional deposition techniques such as off-center spin-coating. In this study, we compare these deposition techniques by applying them to a green-emitting conjugated polymer material that exhibits liquid crystalline phase behavior. Our study reveals that while methods such as electrospinning and mechanical rubbing can be useful to locally generate polymer chain alignment, the combination of epitaxial growth using 1,3,5-trichlorobenzene as crystallizing agent with off-center spin-coating results in the formation of anisotropic nanofiber-like structures with enhanced crystallinity degree and polarized light-emission properties. The unidirectional epitaxial growth was also applied to a red-emitting polymer that exhibits polarization ratios up to 4.1. Our results emphasize that this simple solution formulation and process can be used for the fabrication of polarized thin films of a variety of conjugated polymers with potential applications in the advanced display technologies or analytical equipment fields.

Intra-entrepreneurial culture and its effect on the innovation´s academic spin-offn-off

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Mauricio Monge Agüero

2016-10-01

Full Text Available This research aims empirically verify relationship between the intrapreneurship culture and innovation in companies denominated Spin-off academic of Costa Rican public universities. We found and studied 44 Spin-off academic, we use IBM SPSS statistics 19 Software and make descriptive and correlation analysis, are revealing that the more used practices are teamwork, risk tolerance and compensation and incentives; and to a lesser extent, practices of support of management and flexibility in corporate structure, and empower reviewers. About incidence of entrepreneurship on a Culture of innovation, the results showed that exists no effect on the variables of a autonomy, b risk tolerance, c compensation and incentives and d teamwork. However, a very positive and significant result was obtained for practice support of management and flexibility of the corporate structure, for processes innovation. These findings are important for academic entrepreneurs, as it enables them test the usefulness of a corporate entrepreneurship culture for the development of their organizations. They are also important for academic institutions, because allows them promote programs of research, training and consulting in the field of entrepreneurship, and thus achieve greater innovation and business competitiveness.

Spin-polarized free electron beam interaction with radiation and superradiant spin-flip radiative emission

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A. Gover

2006-06-01

Full Text Available The problems of spin-polarized free-electron beam interaction with electromagnetic wave at electron-spin resonance conditions in a magnetic field and of superradiant spin-flip radiative emission are analyzed in the framework of a comprehensive classical model. The spontaneous emission of spin-flip radiation from electron beams is very weak. We show that the detectivity of electron spin resonant spin-flip and combined spin-flip/cyclotron-resonance-emission radiation can be substantially enhanced by operating with ultrashort spin-polarized electron beam bunches under conditions of superradiant (coherent emission. The proposed radiative spin-state modulation and the spin-flip radiative emission schemes can be used for control and noninvasive diagnostics of polarized electron/positron beams. Such schemes are of relevance in important scattering experiments off nucleons in nuclear physics and off magnetic targets in condensed matter physics.

I ritorni di Magwitch. Adattamenti, spin-off, riscritture sul forzato dickensiano

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Claudia Cao

2017-11-01

Full Text Available Great Expectations is probably the most adapted and rewritten work of the Dickensian literary production. Since the author’s adaptation for his public readings, it was clear that the narration was not focused on the love story between Pip and Estella, but on the relationship between the orphan and the convict, his second father. In the last decades numerous transpositions have confirmed that Magwitch, despite his diegetic marginality, is the classic’s most magnetic character: The Boy and the Convict by Aylott (1909, Great Expectations: The Untold Story by Burstall (1987, Magwitch by Noonan (1982, Jack Maggs by Carey (1997, the recent spin-off by Supple, Magwitch (2012, and a self-published trilogy by Lester (2010-2011 feature Magwitch as a main character, to redeem him and to give him a better destiny than Dickens did. After an overview of the reasons for his reception, and a section on the transposing strategies used by rewritings and adaptations, this paper aims at showing the new attention to the theme of fatherhood or parenthood to which this character is strictly related. In particular, keeping in mind Sadrin’s analysis of Great Expectations in terms of the “family romance”, these works shed light on the metaphorical and metonymical meaning of Magwitch’s relationship with Britain and Australia.

Longitudinal double-spin asymmetry for inclusive jet production in p+p collisions at √ps=200 GeV

NARCIS (Netherlands)

Abelev, B.I.; Bai, Y.; Benedosso, F.; Botje, M.A.J.; Grebenyuk, O.; Mischke, A.; Peitzmann, T.; Russcher, M.J.; Snellings, R.J.M.; van der Kolk, N.

2008-01-01

We report a new STAR measurement of the longitudinal double-spin asymmetry A_LL for inclusive jet production at mid-rapidity in polarized p+p collisions at a center-of-mass energy of sqrt(s) = 200 GeV. The data, which cover jet transverse momenta 5

Effective moments of inertia and spin cut off parameters in Hf isotopes

International Nuclear Information System (INIS)

Razavi, R.; Sharifzadeh, N.; Farahmand, M.R.

2011-01-01

In all statistical theories the nuclear level density is the most characteristic quantity and plays a major role in the study of nuclear structure. Most experimental data on nuclear level density have been analyzed with analytical functions of the level density. On the basis of statistical models, the effective moments of inertia and spin cut off parameters have been determined for 176 Hf, 178 Hf and 180 Hf nuclei from extensive and complete level schemes and neutron resonance densities in low excitation energy levels. Then, moments of inertia of these nuclei have been determined by nuclear rotational model. The results have been compared with their corresponding rigid body value

The Specifics of Tax Arbitrage in The Reorganization of The European Companies Through Acquisitions, Mergers, Spin-Offs and Disinvestments

Directory of Open Access Journals (Sweden)

Anda Simona Rădulescu (Dîrvă

2016-03-01

Full Text Available Focusing on fiscal issues, in this paper we analyzed the trend of European companies to streamline their activity through legal reorganization (i.e. takeovers, mergers, spin-offs, divestments starting from tax benefits which may result from such operations.

Multiphoton electronic-spin generation and transmission spectroscopy in n-type GaAs

Energy Technology Data Exchange (ETDEWEB)

Idrish Miah, M., E-mail: m.miah@griffith.edu.a [Department of Physics, University of Chittagong, Chittagong 4331 (Bangladesh)

2011-01-17

Multiphoton electronic-spin generation in semiconductors was investigated using differential transmission spectroscopy. The generation of the electronic spins in the semiconductor samples were achieved by multiphoton pumping with circularly polarized light beam and was probed by the spin-resolved transmission of the samples. The electronic spin-polarization of conduction band was estimated and was found to depend on the delay of the probe beam, temperature as well as on the multiphoton pumping energy. The temperature dependence showed a decrease of the spin-polarization with increasing temperature. The electronic spin-polarization was found to depolarize rapidly for multiphoton pumping energy larger than the energy gap of the split-off band to the conduction band. The results were compared with those obtained in one-photon pumping, which shows that an enhancement of the electronic spin-polarization was achieved in multiphoton pumping. The findings resulting from this investigation might have potential applications in opto-spintronics, where the generation of highly polarized electronic spins is required.

Multiphoton electronic-spin generation and transmission spectroscopy in n-type GaAs

International Nuclear Information System (INIS)

Idrish Miah, M.

2011-01-01

Multiphoton electronic-spin generation in semiconductors was investigated using differential transmission spectroscopy. The generation of the electronic spins in the semiconductor samples were achieved by multiphoton pumping with circularly polarized light beam and was probed by the spin-resolved transmission of the samples. The electronic spin-polarization of conduction band was estimated and was found to depend on the delay of the probe beam, temperature as well as on the multiphoton pumping energy. The temperature dependence showed a decrease of the spin-polarization with increasing temperature. The electronic spin-polarization was found to depolarize rapidly for multiphoton pumping energy larger than the energy gap of the split-off band to the conduction band. The results were compared with those obtained in one-photon pumping, which shows that an enhancement of the electronic spin-polarization was achieved in multiphoton pumping. The findings resulting from this investigation might have potential applications in opto-spintronics, where the generation of highly polarized electronic spins is required.

Longitudinal and transverse spin asymmetries for inclusive jet production at mid-rapidity in polarized p+p collisions at root s=200 GeV

Czech Academy of Sciences Publication Activity Database

Adamczyk, L.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alakhverdyants, A. V.; Alekseev, I.; Alford, J.; Anderson, B. D.; Anson, C.; Barnovská, Zuzana; Bielčík, J.; Bielčíková, Jana; Chaloupka, Petr; Chung, Paul; Hajková, O.; Kapitán, Jan; Pachr, M.; Rusňák, Jan; Šumbera, Michal; Tlustý, David

2012-01-01

Roč. 86, č. 3 (2012), s. 032006 ISSN 1550-7998 R&D Projects: GA MŠk LA09013 Institutional support: RVO:61389005 Keywords : jet production * hadron production * spin assymmetry Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 4.691, year: 2012

Two-photon spin-polarization spectroscopy in silicon-doped GaAs.

Science.gov (United States)

Miah, M Idrish

2009-05-14

We generate spin-polarized electrons in bulk GaAs using circularly polarized two-photon pumping with excess photon energy (DeltaE) and detect them by probing the spin-dependent transmission of the sample. The spin polarization of conduction band electrons is measured and is found to be strongly dependent on DeltaE. The initial polarization, pumped with DeltaE=100 meV, at liquid helium temperature is estimated to be approximately 49.5%, which is very close to the theoretical value (50%) permitted by the optical selection rules governing transitions from heavy-hole and light-hole states to conduction band states in a bulk sample. However, the polarization pumped with larger DeltaE decreases rapidly because of the exciting carriers from the split-off band.

Quantum Correlation in Matrix Product States of One-Dimensional Spin Chains

International Nuclear Information System (INIS)

Zhu Jing-Min

2015-01-01

For our proposed composite parity-conserved matrix product state (MPS), if only a spin block length is larger than 1, any two such spin blocks have correlation including classical correlation and quantum correlation. Both the total correlation and the classical correlation become larger than that in any subcomponent; while the quantum correlations of the two nearest-neighbor spin blocks and the two next-nearest-neighbor spin blocks become smaller and for other conditions the quantum correlation becomes larger, i.e., the increase or the production of the long-range quantum correlation is at the cost of reducing the short-range quantum correlation, which deserves to be investigated in the future; and the ration of the quantum correlation to the total correlation monotonically decreases to a steady value as the spacing spin length increasing. (paper)

Quantum measurement of a rapidly rotating spin qubit in diamond.

Science.gov (United States)

Wood, Alexander A; Lilette, Emmanuel; Fein, Yaakov Y; Tomek, Nikolas; McGuinness, Liam P; Hollenberg, Lloyd C L; Scholten, Robert E; Martin, Andy M

2018-05-01

A controlled qubit in a rotating frame opens new opportunities to probe fundamental quantum physics, such as geometric phases in physically rotating frames, and can potentially enhance detection of magnetic fields. Realizing a single qubit that can be measured and controlled during physical rotation is experimentally challenging. We demonstrate quantum control of a single nitrogen-vacancy (NV) center within a diamond rotated at 200,000 rpm, a rotational period comparable to the NV spin coherence time T 2 . We stroboscopically image individual NV centers that execute rapid circular motion in addition to rotation and demonstrate preparation, control, and readout of the qubit quantum state with lasers and microwaves. Using spin-echo interferometry of the rotating qubit, we are able to detect modulation of the NV Zeeman shift arising from the rotating NV axis and an external DC magnetic field. Our work establishes single NV qubits in diamond as quantum sensors in the physically rotating frame and paves the way for the realization of single-qubit diamond-based rotation sensors.

Spin transfers for baryon production in polarized pp collisions at RHIC-BNL

International Nuclear Information System (INIS)

Ma BoQiang; Schmidt, Ivan; Soffer, Jacques; Yang Jianjun

2002-01-01

We consider the inclusive production of longitudinally polarized baryons in p→p collisions at RHIC-BNL, with one longitudinally polarized proton. We study the spin transfer between the initial proton and the produced baryon as a function of its rapidity and we elucidate its sensitivity to the quark helicity distributions of the proton and to the polarized fragmentation functions of the quark into the baryon. We make predictions using an SU(6) quark spectator model and a perturbative QCD (pQCD) based model. We discuss these different predictions, and what can be learned from them, in view of the forthcoming experiments at RHIC-BNL

Measurement of Double Longitudinal Spin Asymmetry, ALL, for Inclusive 0̂ Production at Forward Rapidity in PHENIX for √s=200 and 500 GeV

Science.gov (United States)

Wolin, Scott

2010-11-01

The Relativistic Heavy Ion Collider (RHIC) is the world's only source of polarized proton-proton collisions which provides access at leading order to δ G(x), the gluon contribution to the proton spin. Previously, PHENIX has only been sensitive to truncated moments of δ G over the limited Bjorken-x range of 0.05 Piston Calorimeter (MPC) at forward rapidity, di-hadron measurements with hadrons at both forward and central rapidities are now possible in PHENIX. Two forward hadrons extend the kinematic coverage for gluons down to x˜10-3. Such an asymmetry measurement for di-hadrons and single hadrons at forward rapidity can be used to improve the constraints on δ G(x) at small x. Here, we discuss the status of these measurements at forward rapidity in PHENIX using the MPC.

Review of underground logistic systems in the Netherlands : An ex-post evaluation of barriers, enablers and spin-offs

NARCIS (Netherlands)

Wiegmans, B.W.; Visser, J.; Konings, R.; Pielage, B.J.A.

2010-01-01

Now, 10 years after the first plans, we analyse in this paper what has happened with Underground Logistic Systems (ULS). The major question in this paper is: Which barriers and enablers led to the failure of ULS and what ULS spin-offs can be found nowadays? Several factors can be classified as

Tipologías de programas de apoyo a la creación de spin-offs en las universidades: Reino Unido y España

Directory of Open Access Journals (Sweden)

José María Beraza

2012-01-01

Full Text Available Diversos autores han propuesto distintos modelos de políticas de apoyo a la creación de spin-offs académicas (Clarysse et al., 2002; Clarysse et al., 2005; Degroof, 2002; Roberts y Malone, 1996; Wright et al., 2007. El presente trabajo identifica diferentes modelos de programas de apoyo a la creación de spin-offs en las universidades del Reino Unido y España, y analiza las características diferenciadoras de cada uno de estos modelos. Dado que cada una de estos dos países tiene un contexto y características particulares, así como distintos grados de experiencia en este tipo de programas, resulta razonable suponer que no exista un modelo único. Además, la identificación y caracterización de grupos de universidades con similares programas facilitará el planteamiento de pautas para orientar la actuación universitaria al objeto de conseguir que el apoyo a la creación de spinoffs resulte más eficaz. Este análisis se realiza a partir de los datos recabados a través de una encuesta, dirigida a responsables de programas de apoyo a la creación de spin-offs en universidades, a los que se ha aplicado la técnica de análisis cluster. Este análisis ha permitido identificar cuatro tipos de programas de apoyo a la creación de spin-offs significativamente diferentes en las universidades del Reino Unido y otros cuatro en las españolas. Además, ha confirmado la existencia en el Reino Unido de programas diferentes en términos de recursos, compromiso de la universidad, proactividad y selectividad; y en las universidades españolas, además de en estas cuatro variables, también ha apreciado diferencias en términos de experiencia y número de spin-offs creadas. Asimismo, entre los tipos de programas identificados, ha encontrado uno en el Reino Unido y dos en España que parecen ser modelos de éxito. También reafirma la importancia dada por la literatura a la existencia de un entorno favorable para el éxito de estos programas.

Peningkatan Ketaatan Syariah Melalui Pemisahan (Spin-off Unit Usaha Syariah Bank Umum Konvensional

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Khotibul Umam

2012-02-01

Full Text Available Pursuant to Act 21/2008, Conventional Commercial Banks with embedded Sharia Business Unit are obliged to spin-off their unit when its asset value has reached 50% of the total asset of Bank’s. This obligation attempts to separate the management of SBU from Banks, thus expecting higher rate of sharia compliance. Menurut UU 21/2008, Bank Umum Konvensional yang memiliki Unit Usaha Syariah wajib memisahkan unitnya apabila nilai aset unit tersebut telah mencapai 50% dari total aset bank induk. Kewajiban tersebut ditujukan untuk menjadikannya sebagai Bank Umum Syariah yang terpisah pengelolaannya dari Bank Umum Konvensional, sehingga diharapkan lebih taat terhadap prinsip syariah.

Single Top Quark Production at the LHC Understanding Spin

CERN Document Server

Mahlon, G; Mahlon, Gregory; Parke, Stephen

2000-01-01

We show that the single top quarks produced in the Wg-fusion channel at a proton-proton collider at a center-of-mass energy sqrt{s}=14 TeV posses a high degree of polarization in terms of a spin basis which decomposes the top quark spin in its rest frame along the direction of the spectator jet. A second useful spin basis is the eta-beamline basis, which decomposes the top quark spin along one of the two beam directions, depending on which hemisphere contains the spectator jet. We elucidate the interplay between the two- and three-body final states contributing to this production cross section in the context of determining the spin decomposition of the top quarks, and argue that the zero momentum frame helicity is undefined. We show that the usefulness of the spectator and eta-beamline spin bases is not adversely affected by the cuts required to separate the Wg-fusion signal from the background.

Proposal for a dual-gate spin field effect transistor: A device with very small switching voltage and a large ON to OFF conductance ratio

Science.gov (United States)

Wan, J.; Cahay, M.; Bandyopadhyay, S.

2008-06-01

We propose a new dual gate spin field effect transistor (SpinFET) consisting of a quasi one-dimensional semiconductor channel sandwiched between two half-metallic contacts. The gate voltage aligns and de-aligns the incident electron energy with Ramsauer resonance levels in the channel, thereby modulating the source-to-drain conductance. The device can be switched from ON to OFF with a few mV change in the gate voltage, resulting in exceedingly low dynamic power dissipation during switching. The conductance ON/OFF ratio stays fairly large ( ∼60) up to a temperature of 10 K. This conductance ratio is comparable to that achievable with carbon nanotube transistors.

Factores determinantes de la creación de las Spin Off académicas: caso del Instituto Tecnológico de Costa Rica

Directory of Open Access Journals (Sweden)

Mauricio Monge

2011-12-01

Full Text Available Este trabajo tiene como objetivo analizar los factores determinantes en la creación de Spin off académicas en el Instituto Tecnológico de Costa Rica (ITCR, universidad pública de Costa Rica, utilizando la metodología propuesta por O'Shea et al., (2008: atributos del emprendedor, recursos organizativos, determinantes institucionales y ambientales. Los resultados relevan que en el ITCR la principal fortaleza es su misión, cultura e historia, caracterizada por el servicio brindado al sector productivo; no obstante, requiere fortalecer aspectos como la calidad de la investigación y consecución de fondos externos para esta, así como aspectos externos de índole legal que brinden las condiciones apropiadas para la creación de spin off académicas, y la generación de capital de riesgo. Todo ello, a tono con el paradigma de la universidad emprendedora. Este artículo contribuye a explicar el proceso de creación de Spin off en una universidad pública latinoamericana y es de utilidad tanto para el ámbito académico, como público y privado encargado de impulsar un mayor acercamiento entre la Universidad y la Sociedad

Corporate Governance Models as a Bridge for Linking Academic and Non-Academic Entrepreneurs: The Case of Italian Spin-Offs

Science.gov (United States)

Parente, Roberto; Feola, Rosangela; Petrone, Michele

2011-01-01

This paper reports an investigation of governance issues in Italian academic spin-offs that arise from the need to balance the powers of two categories of partner: academic inventors and external investors (such as established companies and venture capital funds). The relationship between inventors and external investors, jointly pursuing a…

Spin-offs of the Third Mission and social innovation: the case study of the research–training–intervention project of Geodata Ltd

Directory of Open Access Journals (Sweden)

Del Gottardo Ezio

2016-12-01

Full Text Available As a result of enactment of Law 297/1999, many Italian universities could improve the opportunities in applied research, activating spin-offs and start-ups in conformity with those regulations. This is a new challenge in the universities’ mission: universities are capable (and therefore they are asked to generate not only new knowledge and competent professional profiles, but also to make a new effort in implementing the “third mission” for promoting social innovation. Considering this background, we present a research project - a training intervention named “Participatory culture, personal branding and organisational wellness” - by Espéro Pvt, a spin-off of the University of Salento, for Geodata Engineering Ltd., located in Turin, Italy. Presented below are the theoretical framework (learning organisation, empowerment evaluation and organisational wellness and the methodology, as well as the first results.

Spin Polarization Oscillations without Spin Precession: Spin-Orbit Entangled Resonances in Quasi-One-Dimensional Spin Transport

Directory of Open Access Journals (Sweden)

D. H. Berman

2014-03-01

Full Text Available Resonant behavior involving spin-orbit entangled states occurs for spin transport along a narrow channel defined in a two-dimensional electron gas, including an apparent rapid relaxation of the spin polarization for special values of the channel width and applied magnetic field (so-called ballistic spin resonance. A fully quantum-mechanical theory for transport using multiple subbands of the one-dimensional system provides the dependence of the spin density on the applied magnetic field and channel width and position along the channel. We show how the spatially nonoscillating part of the spin density vanishes when the Zeeman energy matches the subband energy splittings. The resonance phenomenon persists in the presence of disorder.

Quantum phase transitions in matrix product states of one-dimensional spin-1 chains

International Nuclear Information System (INIS)

Zhu Jingmin

2014-01-01

We present a new model of quantum phase transitions in matrix product systems of one-dimensional spin-1 chains and study the phases coexistence phenomenon. We find that in the thermodynamic limit the proposed system has three different quantum phases and by adjusting the control parameters we are able to realize any phase, any two phases equal coexistence and the three phases equal coexistence. At every critical point the physical quantities including the entanglement are not discontinuous and the matrix product system has long-range correlation and N-spin maximal entanglement. We believe that our work is helpful for having a comprehensive understanding of quantum phase transitions in matrix product states of one-dimensional spin chains and of certain directive significance to the preparation and control of one-dimensional spin lattice models with stable coherence and N-spin maximal entanglement. (author)

A rapidly spinning supermassive black hole at the centre of NGC 1365

DEFF Research Database (Denmark)

Risaliti, G.; Harrison, F. A.; Madsen, K. K.

2013-01-01

and relativistic effects near the black hole, the line shape being sensitive to its spin. Alternative models in which the distortions result from absorption by intervening structures provide an equally good description of the data, and there has been no general agreement on which is correct. Recent claims...... that the black hole (2 × 10(6) solar masses) at the centre of the galaxy NGC 1365 is rotating at close to its maximum possible speed rest on the assumption of relativistic reflection. Here we report X-ray observations of NGC 1365 that reveal the relativistic disk features through broadened Fe-line emission...... and an associated Compton scattering excess of 10-30 kiloelectronvolts. Using temporal and spectral analyses, we disentangle continuum changes due to time-variable absorption from reflection, which we find arises from a region within 2.5 gravitational radii of the rapidly spinning black hole. Absorption...

Market Trial: Selling Off-Grid Lighting Products in Rural Kenya

Energy Technology Data Exchange (ETDEWEB)

Tracy, Jennifer; Alstone, Peter; Jacobson, Arne; Mills, Evan

2010-06-21

In this study, we performed a market trial of off-grid LED lighting products in Maai Mahiu, arural Kenyan town. Our goals were to assess consumer demand and consumer preferences with respect to off-grid lighting systems and to gain feedback from off-grid lighting users at the point of purchase and after they have used to products for some time.

Research on the relationship of institutional innovation, organizational learning and synergistic effect: An empirical study of chineses university spin-offs

Directory of Open Access Journals (Sweden)

Zhang Hao

2014-06-01

Full Text Available Purpose: At present, the Central Government of China pays more attention to the synergistic innovation, and the national strategy policy of “innovation driven development” are made to implementations. Thus, the university plays an important role in the national innovation system, so that how the university gets involved in innovative activities becomes the primary problem of innovation strategy. This paper utilizes Chinese university spin-offs survey data to identify the influence process from institutional innovation and organizational learning to synergistic effect of organization. Design/methodology/approach: Firstly, we found that following the procedural view, each one of these three elements can be divided into two parts. Then, we established structural equation modeling with the connections between these six subdivisions. Secondly, by taking 270 university Spin-offs in China as samples, we verified the fit of the model through statistical data on the questionnaire survey. Thirdly, we analyzed the relationship and influence path of the institutional innovation, organizational learning and synergistic effect. Findings: The results of empirical research show that institutional implementation process is positive correlation on both sides of synergistic effect, and, the intermediary role is obvious that external organizational learning played a regulatory role between institutional innovation synergistic effects. Research limitations/implications: A large-scale questionnaire survey showed that the influence path of “institutions -organization-innovation performance" are existed. Therefore, the system analysis framework should be introduced to the emergence and development of University spin-offs, and further explored the synergistic process of institutional change and organizational evolution. Practical implications: University spin-offs are a mode of university - industry cooperation, and it takes participation in market competition

Spin-Projected Matrix Product States: Versatile Tool for Strongly Correlated Systems.

Science.gov (United States)

Li, Zhendong; Chan, Garnet Kin-Lic

2017-06-13

We present a new wave function ansatz that combines the strengths of spin projection with the language of matrix product states (MPS) and matrix product operators (MPO) as used in the density matrix renormalization group (DMRG). Specifically, spin-projected matrix product states (SP-MPS) are constructed as [Formula: see text], where [Formula: see text] is the spin projector for total spin S and |Ψ MPS (N,M) ⟩ is an MPS wave function with a given particle number N and spin projection M. This new ansatz possesses several attractive features: (1) It provides a much simpler route to achieve spin adaptation (i.e., to create eigenfunctions of Ŝ 2 ) compared to explicitly incorporating the non-Abelian SU(2) symmetry into the MPS. In particular, since the underlying state |Ψ MPS (N,M) ⟩ in the SP-MPS uses only Abelian symmetries, one does not need the singlet embedding scheme for nonsinglet states, as normally employed in spin-adapted DMRG, to achieve a single consistent variationally optimized state. (2) Due to the use of |Ψ MPS (N,M) ⟩ as its underlying state, the SP-MPS can be closely connected to broken-symmetry mean-field states. This allows one to straightforwardly generate the large number of broken-symmetry guesses needed to explore complex electronic landscapes in magnetic systems. Further, this connection can be exploited in the future development of quantum embedding theories for open-shell systems. (3) The sum of MPOs representation for the Hamiltonian and spin projector [Formula: see text] naturally leads to an embarrassingly parallel algorithm for computing expectation values and optimizing SP-MPS. (4) Optimizing SP-MPS belongs to the variation-after-projection (VAP) class of spin-projected theories. Unlike usual spin-projected theories based on determinants, the SP-MPS ansatz can be made essentially exact simply by increasing the bond dimensions in |Ψ MPS (N,M) ⟩. Computing excited states is also simple by imposing orthogonality constraints

Highlights from PHENIX transverse spin program at RHIC

International Nuclear Information System (INIS)

Liu, M.

2013-01-01

In recent years, there has been exciting development in both experimental and theoretical studies of transverse spin phenomena in high energy polarized p+p and polarized DIS collisions. In the p+p frontier, the polarized p+p collider at RHIC provides a unique opportunity to investigate the novel physics that causes the large spin effects seen in the transversely polarized p+p collisions over the past 30 years, particularly in the forward rapidity. Since the beginning, PHENIX has been conducting a very active transverse spin physics program to study Sivers, Collins and other novel spin effects at RHIC, including measurements of transverse single spin asymmetry (TSSA) in light and heavy quark productions, leading neutron TSSA in the very forward rapidity, and di-hadron (and 'jet') spin correlations in a wide kinematics range, just to name a few. In 2012, PHENIX collected transversely polarized 200 GeV p+p data with a record high luminosity of 9.24 pb −1 , with an average beam polarization of 58%. In this talk, I highlight the recent results from the PHENIX experiment, and also briefly discuss the near-term prospects of new transverse spin measurements only possible with the latest (forward) silicon vertex detectors, (F)VTX, and the upcoming forward MPC-EX upgrade detectors.

Spin-polarized transport in a normal/ferromagnetic/normal zigzag graphene nanoribbon junction

International Nuclear Information System (INIS)

Tian Hong-Yu; Wang Jun

2012-01-01

We investigate the spin-dependent electron transport in single and double normal/ferromagnetic/normal zigzag graphene nanoribbon (NG/FG/NG) junctions. The ferromagnetism in the FG region originates from the spontaneous magnetization of the zigzag graphene nanoribbon. It is shown that when the zigzag-chain number of the ribbon is even and only a single transverse mode is actived, the single NG/FG/NG junction can act as a spin polarizer and/or a spin analyzer because of the valley selection rule and the spin-exchange field in the FG, while the double NG/FG/NG/FG/NG junction exhibits a quantum switching effect, in which the on and the off states switch rapidly by varying the cross angle between two FG magnetizations. Our findings may shed light on the application of magnetized graphene nanoribbons to spintronics devices. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Spin conversion induced by spin-orbit interaction in positronium collisions

International Nuclear Information System (INIS)

Saito, H; Nakayama, T; Hyodo, T

2009-01-01

The positronium spin conversion reaction induced by spin-orbit interaction is investigated. We obtain the reaction rates during positronium-Xe and positronium-Kr collisions by using the Zeeman mixing of positronium states. At thermal energies corresponding to room temperature, the reaction rate for spin conversion due to spin-orbit interaction is found to be almost twice that for the positronium pick-off reaction. We also study the energy dependence of the reaction rate. The mean energy of positronium is controlled by changing the gas temperature and using positronium in thermal equilibrium. We found that the reaction rate increases with the collision energy.

Rapid high-resolution spin- and angle-resolved photoemission spectroscopy with pulsed laser source and time-of-flight spectrometer

Science.gov (United States)

Gotlieb, K.; Hussain, Z.; Bostwick, A.; Lanzara, A.; Jozwiak, C.

2013-09-01

A high-efficiency spin- and angle-resolved photoemission spectroscopy (spin-ARPES) spectrometer is coupled with a laboratory-based laser for rapid high-resolution measurements. The spectrometer combines time-of-flight (TOF) energy measurements with low-energy exchange scattering spin polarimetry for high detection efficiencies. Samples are irradiated with fourth harmonic photons generated from a cavity-dumped Ti:sapphire laser that provides high photon flux in a narrow bandwidth, with a pulse timing structure ideally matched to the needs of the TOF spectrometer. The overall efficiency of the combined system results in near-EF spin-resolved ARPES measurements with an unprecedented combination of energy resolution and acquisition speed. This allows high-resolution spin measurements with a large number of data points spanning multiple dimensions of interest (energy, momentum, photon polarization, etc.) and thus enables experiments not otherwise possible. The system is demonstrated with spin-resolved energy and momentum mapping of the L-gap Au(111) surface states, a prototypical Rashba system. The successful integration of the spectrometer with the pulsed laser system demonstrates its potential for simultaneous spin- and time-resolved ARPES with pump-probe based measurements.

Surgimiento de empresas catalogadas como spin-off universitarias en Colombia,análisis desde la gerencia de proyectos (fase I

Directory of Open Access Journals (Sweden)

Patricia López Obando

2017-07-01

Full Text Available En el entorno universitario, se viene fomentando la generación de spin-off como alternativa para la construcción de una cultura empresarial, para lo cual se han estructurado estrategias como las incubadoras de empresas de base tecnológica, desde las cuales se espera acelerar las ideas de negocio y posicionarlas en el mercado. Sin embargo, hasta el momento, no se cuenta con un estudio que permita establecer los alcances que se han obtenido respecto de su surgimiento, consolidación y conservación, por ello, se espera con gerencia de proyectos determinar las características bajo las cuales surgen, establecer las condiciones para su mantenimiento de manera exitosa y según esto determinar el tipo de gerencia que se desarrolla en su interior para verificar las variables que intervienen en su aporte al ambiente empresarial. Se pretende aquí realizar la revisión de literatura en torno al desarrollo de las spin-off en Colombia y su tratamiento en cuanto proyecto e investigación realizada a su alrededor

Magnetic Nanostructures Spin Dynamics and Spin Transport

CERN Document Server

Farle, Michael

2013-01-01

Nanomagnetism and spintronics is a rapidly expanding and increasingly important field of research with many applications already on the market and many more to be expected in the near future. This field started in the mid-1980s with the discovery of the GMR effect, recently awarded with the Nobel prize to Albert Fert and Peter Grünberg. The present volume covers the most important and most timely aspects of magnetic heterostructures, including spin torque effects, spin injection, spin transport, spin fluctuations, proximity effects, and electrical control of spin valves. The chapters are written by internationally recognized experts in their respective fields and provide an overview of the latest status.

Rapid Gradient-Echo Imaging

Science.gov (United States)

Hargreaves, Brian

2012-01-01

Gradient echo sequences are widely used in magnetic resonance imaging (MRI) for numerous applications ranging from angiography to perfusion to functional MRI. Compared with spin-echo techniques, the very short repetition times of gradient-echo methods enable very rapid 2D and 3D imaging, but also lead to complicated “steady states.” Signal and contrast behavior can be described graphically and mathematically, and depends strongly on the type of spoiling: fully balanced (no spoiling), gradient spoiling, or RF-spoiling. These spoiling options trade off between high signal and pure T1 contrast while the flip angle also affects image contrast in all cases, both of which can be demonstrated theoretically and in image examples. As with spin-echo sequences, magnetization preparation can be added to gradient-echo sequences to alter image contrast. Gradient echo sequences are widely used for numerous applications such as 3D perfusion imaging, functional MRI, cardiac imaging and MR angiography. PMID:23097185

Off-shell representations of maximally-extended supersymmetry

International Nuclear Information System (INIS)

Cox, P.H.

1985-01-01

A general theorem on the necessity of off-shell central charges in representations of maximally-extended supersymmetry (number of spinor charges - 4 x largest spin) is presented. A procedure for building larger and higher-N representations is also explored; a (noninteracting) N=8, maximum spin 2, off-shell representation is achieved. Difficulties in adding interactions for this representation are discussed

Dynamical spin accumulation in large-spin magnetic molecules

Science.gov (United States)

Płomińska, Anna; Weymann, Ireneusz; Misiorny, Maciej

2018-01-01

The frequency-dependent transport through a nanodevice containing a large-spin magnetic molecule is studied theoretically in the Kondo regime. Specifically, the effect of magnetic anisotropy on dynamical spin accumulation is of primary interest. Such accumulation arises due to finite components of frequency-dependent conductance that are off diagonal in spin. Here, employing the Kubo formalism and the numerical renormalization group method, we demonstrate that the dynamical transport properties strongly depend on the relative orientation of spin moments in electrodes of the device, as well as on intrinsic parameters of the molecule. In particular, the effect of dynamical spin accumulation is found to be greatly affected by the type of magnetic anisotropy exhibited by the molecule, and it develops for frequencies corresponding to the Kondo temperature. For the parallel magnetic configuration of the device, the presence of dynamical spin accumulation is conditioned by the interplay of ferromagnetic-lead-induced exchange field and the Kondo correlations.

Production and Detection of Spin-Entangled Electrons in Mesoscopic Conductors

Science.gov (United States)

Burkard, Guido

2006-03-01

Electron spins are an extremely versatile form of quantum bits. When localized in quantum dots, they can form a register for quantum computation. Moreover, being attached to a charge in a mesoscopic conductor allows the electron spin to play the role of a mobile carrier of quantum information similarly to photons in optical quantum communication. Since entanglement is a basic resource in quantum communication, the production and detection of spin-entangled Einstein-Podolsky-Rosen (EPR) pairs of electrons are of great interest. Besides the practical importance, it is of fundamental interest to test quantum non-locality for electrons. I review the theoretical schemes for the entanglement production in superconductor-normal junctions [1] and other systems. The electron spin entanglement can be detected and quantified from measurements of the fluctuations (shot noise) of the charge current after the electrons have passed through an electronic beam splitter [2,3]. This two-particle interference effect is related to the Hanbury-Brown and Twiss experiment and leads to a doubling of the shot noise SI=φ=0 for spin-entangled states, allowing their differentiation from unentangled pairs. I report on the role of spin-orbit coupling (Rashba and Dresselhaus) in a complete characterization of the spin entanglement [4]. Finally, I address the effects of a discrete level spectrum in the mesoscopic leads and of backscattering and decoherence.[1] P. Recher, E. V. Sukhorukov, D. Loss, Phys. Rev. B 63, 165314 (2001)[2] G. Burkard, D. Loss, E. V. Sukhorukov, Phys. Rev. B 61, R16303 (2000)[3] G. Burkard and D. Loss, Phys. Rev. Lett.91, 087903 (2003)[4] J. C. Egues, G. Burkard, D. Saraga, J. Schliemann, D. Loss, cond-mat/0509038, to appear in Phys.Rev.B (2005).

Half-metallic superconducting triplet spin multivalves

Science.gov (United States)

Alidoust, Mohammad; Halterman, Klaus

2018-02-01

We study spin switching effects in finite-size superconducting multivalve structures. We examine F1F2SF3 and F1F2SF3F4 hybrids where a singlet superconductor (S) layer is sandwiched among ferromagnet (F) layers with differing thicknesses and magnetization orientations. Our results reveal a considerable number of experimentally viable spin-valve configurations that lead to on-off switching of the superconducting state. For S widths on the order of the superconducting coherence length ξ0, noncollinear magnetization orientations in adjacent F layers with multiple spin axes leads to a rich variety of triplet spin-valve effects. Motivated by recent experiments, we focus on samples where the magnetizations in the F1 and F4 layers exist in a fully spin-polarized half-metallic phase, and calculate the superconducting transition temperature, spatially and energy resolved density of states, and the spin-singlet and spin-triplet superconducting correlations. Our findings demonstrate that superconductivity in these devices can be completely switched on or off over a wide range of magnetization misalignment angles due to the generation of equal-spin and opposite-spin triplet pairings.

Suzaku Observations of 4U 1957+11: Potentially the Most Rapidly Spinning Black Hole in (the Halo of) the Galaxy

Science.gov (United States)

Nowak, Michael A.; Wilms, Joern; Pottschmidt, Katja; Schulz, Norbert; Maitra, Dipankar; Miller, Jon

2011-01-01

We present three Suzaku observations of the black hole candidate 4U 1957+11 (V 1408 Aql) - a source that exhibits some of. the simplest and cleanest examples of soft, disk-dominated spectra. 4U 1957+ II also presents among the. highest peak temperatures found from disk-dominated spectra. Such temperatures may be associated with rapid black hole spin. The 4U 1957+11 spectra also require a very low normalization, which can be explained by a combination of small inner disk radius and a large distance (> 10 kpc) which places 4U 1957+ 11 well into the Galactic halo. We perform Joint fits to the Suzaku spectra with both relativistic and Comptonized disk models. Assuming a low mass black hole and the nearest distance (3 Stellar Mass, 10 kpc), the dimensionless spin parameter a* = Jc/GM(sup 2)> or approx. 0.9. Higher masses and farther distances yield a* approx. = 1. Similar conclusions are reached with Comptonization models; they imply a combination of small inner disk radii (or, equivalently, rapid spin) and large distance. Low spin cannot be recovered unless 4U 1957+11 is a low mass black hole that is at the unusually large distance of > or approx.40 kpc. We speculate whether the suggested maximal spin is related to how the system came to reside in the halo.

Off-shell spinor-helicity amplitudes from light-cone deformation procedure

Energy Technology Data Exchange (ETDEWEB)

Ponomarev, Dmitry [Theoretical physics group, Blackett Laboratory, Imperial College London,London, SW7 2AZ (United Kingdom)

2016-12-22

We study the consistency conditions for interactions of massless fields of any spin in four-dimensional flat space using the light-cone approach. We show that they can be equivalently rewritten as the Ward identities for the off-shell light-cone amplitudes built from the light-cone Hamiltonian in the standard way. Then we find a general solution of these Ward identities. The solution admits a compact representation when written in the spinor-helicity form and is given by an arbitrary function of spinor products, satisfying well-known homogeneity constraints. Thus, we show that the light-cone consistent deformation procedure inevitably leads to a certain off-shell version of the spinor-helicity approach. We discuss how the relation between the two approaches can be employed to facilitate the search of consistent interaction of massless higher-spin fields.

The disk wind in the rapidly spinning stellar-mass black hole 4U 1630-472 observed with NuSTAR

DEFF Research Database (Denmark)

King, Ashley L.; Walton, Dominic J.; Miller, Jon M.

2014-01-01

We present an analysis of a short NuSTAR observation of the stellar-mass black hole and low-mass X-ray binary 4U 1630-472. Reflection from the inner accretion disk is clearly detected for the first time in this source, owing to the sensitivity of NuSTAR. With fits to the reflection spectrum, we...... find evidence for a rapidly spinning black hole, (1σ statistical errors). However, archival data show that the source has relatively low radio luminosity. Recently claimed relationships between jet power and black hole spin would predict either a lower spin or a higher peak radio luminosity. We also...

International Networking Strategies in Academic Spin-off Companies: A study of international network building processes and the roles of the top management team and board in influencing internationalization speed and international network range

OpenAIRE

Witsø, Steinar Bukve

2014-01-01

AbstractPurpose International Entrepreneurship (IE) is a new field of multi-disciplinary enquiry that has its roots in studying the fascinating phenomenon of the emergence of born globals. These small- and medium sized firms internationalize at or near their founding and represent a growing number of entrepreneurial firms. A considerable number of born globals are spin-offs which utilize technology originally developed in academic institutions. Academic spin-offs (ASOs) have been studied fr...

Linking environment-productivity trade-offs and correlated uncertainties: Greenhouse gas emissions and crop productivity in paddy rice production systems

International Nuclear Information System (INIS)

Hayashi, Kiyotada; Nagumo, Yoshifumi; Domoto, Akiko

2016-01-01

In comparative life cycle assessments of agricultural production systems, analyses of both the trade-offs between environmental impacts and crop productivity and of the uncertainties specific to agriculture such as fluctuations in greenhouse gas (GHG) emissions and crop yields are crucial. However, these two issues are usually analyzed separately. In this paper, we present a framework to link trade-off and uncertainty analyses; correlated uncertainties are integrated into environment-productivity trade-off analyses. We compared three rice production systems in Japan: a system using a pelletized, nitrogen-concentrated organic fertilizer made from poultry manure using closed-air composting techniques (high-N system), a system using a conventional organic fertilizer made from poultry manure using open-air composting techniques (low-N system), and a system using a chemical compound fertilizer (conventional system). We focused on two important sources of uncertainties in paddy rice cultivation—methane emissions from paddy fields and crop yields. We found trade-offs between the conventional and high-N systems and the low-N system and the existence of positively correlated uncertainties in the conventional and high-N systems. We concluded that our framework is effective in recommending the high-N system compared with the low-N system, although the performance of the former is almost the same as the conventional system. - Highlights: • Correlated uncertainties were integrated into environment-productivity trade-offs. • Life cycle GHG emissions and crop yields were analyzed using field and survey data. • Three rice production systems using chemical or organic fertilizers were compared. • There were portfolio (insurance) effects in matured technologies. • Analysis of trade-offs and correlated uncertainties will be useful for decisions.

Linking environment-productivity trade-offs and correlated uncertainties: Greenhouse gas emissions and crop productivity in paddy rice production systems

Energy Technology Data Exchange (ETDEWEB)

Hayashi, Kiyotada, E-mail: hayashi@affrc.go.jp [Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization, 3-1-3 Kannondai, Tsukuba, Ibaraki 305-8604 (Japan); Nagumo, Yoshifumi [Crop Research Center, Niigata Agricultural Research Institute, 857 Nagakura-machi, Nagaoka, Niigata 940-0826 (Japan); Domoto, Akiko [Mie Prefecture Agricultural Research Institute, 530 Kawakita-cho, Ureshino, Matsusaka, Mie 515-2316 (Japan)

2016-11-15

In comparative life cycle assessments of agricultural production systems, analyses of both the trade-offs between environmental impacts and crop productivity and of the uncertainties specific to agriculture such as fluctuations in greenhouse gas (GHG) emissions and crop yields are crucial. However, these two issues are usually analyzed separately. In this paper, we present a framework to link trade-off and uncertainty analyses; correlated uncertainties are integrated into environment-productivity trade-off analyses. We compared three rice production systems in Japan: a system using a pelletized, nitrogen-concentrated organic fertilizer made from poultry manure using closed-air composting techniques (high-N system), a system using a conventional organic fertilizer made from poultry manure using open-air composting techniques (low-N system), and a system using a chemical compound fertilizer (conventional system). We focused on two important sources of uncertainties in paddy rice cultivation—methane emissions from paddy fields and crop yields. We found trade-offs between the conventional and high-N systems and the low-N system and the existence of positively correlated uncertainties in the conventional and high-N systems. We concluded that our framework is effective in recommending the high-N system compared with the low-N system, although the performance of the former is almost the same as the conventional system. - Highlights: • Correlated uncertainties were integrated into environment-productivity trade-offs. • Life cycle GHG emissions and crop yields were analyzed using field and survey data. • Three rice production systems using chemical or organic fertilizers were compared. • There were portfolio (insurance) effects in matured technologies. • Analysis of trade-offs and correlated uncertainties will be useful for decisions.

Spin Physics at COMPASS

International Nuclear Information System (INIS)

Schill, Christian

2012-01-01

The COMPASS experiment is a fixed target experiment at the CERN SPS using muon and hadron beams for the investigation of the spin structure of the nucleon and hadron spectroscopy. The main objective of the muon physics program is the study of the spin of the nucleon in terms of its constituents, quarks and gluons. COMPASS has accumulated data during 6 years scattering polarized muons off longitudinally or transversely polarized deuteron ( 6 LiD) or proton (NH 3 ) targets. Results for the gluon polarization are obtained from longitudinal double spin cross section asymmetries using two different channels, open charm production and high transverse momentum hadron pairs, both proceeding through the photon-gluon fusion process. Also, the longitudinal spin structure functions of the proton and the deuteron were measured in parallel as well as the helicity distributions for the three lightest quark flavours. With a transversely polarized target, results were obtained with proton and deuteron targets for the Collins and Sivers asymmetries for charged hadrons as well as for identified kaons and pions. The Collins asymmetry is sensitive to the transverse spin structure of the nucleon, while the Sivers asymmetry reflects correlations between the quark transverse momentum and the nucleon spin. Recently, a new proposal for the COMPASS II experiment was accepted by the CERN SPS which includes two new topics: Exclusive reactions like DVCS and DVMP using the muon beam and a hydrogen target to study generalized parton distributions and Drell-Yan measurements using a pion beam and a polarized NH 3 target to study transverse momentum dependent distributions.

Pair production of arbitrary spin particles by electromagnetic fields

International Nuclear Information System (INIS)

Kruglov, S.I.

2006-01-01

The exact solutions of the wave equation for arbitrary spin particles in the field of the soliton-like electric impulse were obtained. The differential probability of pair production of particles by electromagnetic fields has been evaluated on the basis of the exact solutions. As a particular case, the particle pair production in the constant and uniform electric field were studied

Quantum correlation properties in Matrix Product States of finite-number spin rings

Science.gov (United States)

Zhu, Jing-Min; He, Qi-Kai

2018-02-01

The organization and structure of quantum correlation (QC) of quantum spin-chains are very rich and complex. Hence the depiction and measures about the QC of finite-number spin rings deserved to be investigated intensively by using Matrix Product States(MPSs) in addition to the case with infinite-number. Here the dependencies of the geometric quantum discord(GQD) of two spin blocks on the total spin number, the spacing spin number and the environment parameter are presented in detail. We also compare the GQD with the total correlation(TC) and the classical correlation(CC) and illustrate its characteristics. Predictably, our findings may provide the potential of designing the optimal QC experimental detection proposals and pave the way for the designation of optimal quantum information processing schemes.

pH control and rapid mixing in spinning NMR samples

Science.gov (United States)

Yesinowski, James P.; Sunberg, Richard J.; Benedict, James J.

An apparatus is described which permits the acquisition of NMR spectra from spinning 20-mm sample tubes while: (1) constantly monitoring the pH; (2) adding reagents to maintain constant pH (pH-statting); (3) efficiently mixing the added reagent. The apparatus was built to study the spontaneous precipitation of calcium phosphates from supersaturated solutions using 31P NMR. Other applications include the rapid determination of NMR titration curves, and the minimization of temperature gradients in large sample tubes. The apparatus was used to measure the 31P chemical shift titration of dilute phosphoric acid, which yielded accurate shifts for the three species of protonated orthophosphate ion. The bulk magnetic susceptibility of 85% H 3PO 4 relative to a dilute aqueous sample was also measured, and is shown to contribute significantly to chemical shift measurements.

Optically pumped electron spin polarized targets for use in the production of polarized ion beams

International Nuclear Information System (INIS)

Anderson, L.W.

1979-01-01

The production of relatively dense electron spin polarized alkali metal vapor targets by optical pumping with intense cw dye lasers is discussed. The target density and electron spin polarization depend on the dye laser intensity and bandwidth, the magnetic field at the target, and the electron spin depolarization time. For example in a magnetic field of 1.5 x 10 3 G, and using 1 W dye laser with a bandwidth of 10 10 Hz one can construct an electron spin polarized Na vapor target with a target thickness of 1.6 x 10 13 atoms/cm 2 and an average electron spin polarization of about 90% even though the Na atoms are completely depolarized at every wall collision. Possible uses of the electron spin polarized targets for the production of intense beams of polarized H - or 3 He - ions are discussed. (orig.)

Longitudinal spin dependence of massive lepton pair production

International Nuclear Information System (INIS)

Berger, E. L.; Gordon, L. E.; Klasen, M.

2000-01-01

In this paper, the authors summarize recent work in which they demonstrate that the Compton subprocess, q + g -> γ* + q also dominates the Drell-Yan cross section in polarized and unpolarized proton-proton reactions for values of the transverse momentum Q T of the pair that are larger than roughly half of the pair mass Q, Q T > Q/2. The Drell-Yan process is therefore a valuable, heretofore overlooked, independent source of constraints on the spin-averaged and spin-dependent gluon densities. Although the Drell-Yan cross section is smaller than the prompt photon cross section, massive lepton pair production is cleaner theoretically since long-range fragmentation contributions are absent as are the experimental and theoretical complications associated with isolation of the real photon. Moreover, the dynamics of spin-dependence in hard-scattering processes is a sufficiently complex topic, and its understanding at an early stage in its development, that several defensible approaches for extracting polarized parton densities deserve to be pursued with the expectation that consistent results must emerge

Production, detection, storage and release of spin currents

Directory of Open Access Journals (Sweden)

Michele Cini

2015-03-01

Full Text Available Background: Quantum rings connected to ballistic circuits couple strongly to external magnetic fields if the connection is not symmetric. Moreover, properly connected rings can be used to pump currents in the wires giving raise to a number of interesting new phenomena. At half filling using a time-dependent magnetic field in the plane of the ring one can pump a pure spin current, excited by the the spin–orbit interaction in the ring.Results: Such a magnetic current is even under time reversal and produces an electric field instead of the usual magnetic field. Numerical simulations show that one can use magnetizable bodies as storage units to concentrate and save the magnetization in much the same way as capacitors operating with charge currents store electric charge. The polarization obtained in this way can then be used on command to produce spin currents in a wire. These currents show interesting oscillations while the storage units exchange their polarizations.Conclusion: The magnetic production of spin currents can be a useful alternative to optical excitation and electric field methods.

Life history trade-offs imposed by dragline use in two money spiders.

Science.gov (United States)

Bonte, Dries; Verduyn, Lieselot; Braeckman, Bart P

2016-01-01

Trade-offs among life history traits are central to understanding the limits of adaptations to stress. In animals, virtually all decisions taken during life are expected to have downstream consequences. To what degree rare, but energy-demanding, decisions carry over to individual performance is rarely studied in arthropods. We used spiders as a model system to test how single investments in silk use - for dispersal or predator escape - affect individual performance. Silk produced for safe lines and as threads for ballooning is of the strongest kind and is energetically costly, especially when resources are limited. We induced dragline spinning in two species of money spider at similar quantities to that under natural conditions and tested trade-offs with lifespan and egg sac production under unlimited prey availability and a dietary restriction treatment. We demonstrate strong trade-offs between dragline spinning and survival and fecundity. Survival trade-offs were additive to those imposed by the dietary treatment, but a reduction in eggs produced after silk use was only prevalent under conditions where food was restricted during the spider's life. Because draglines are not recycled after their use for dispersal or predator escape, their spinning incurs substantial fitness costs in dispersal, especially in environments with prey limitation. Rare but energetically costly decisions related to dispersal or predator escape may thus carry over to adult performance and explain phenotypic heterogeneity in natural populations. © 2016. Published by The Company of Biologists Ltd.

The open XXX spin chain in the SoV framework: scalar product of separate states

Science.gov (United States)

Kitanine, N.; Maillet, J. M.; Niccoli, G.; Terras, V.

2017-06-01

We consider the XXX open spin-1/2 chain with the most general non-diagonal boundary terms, that we solve by means of the quantum separation of variables (SoV) approach. We compute the scalar products of separate states, a class of states which notably contains all the eigenstates of the model. As usual for models solved by SoV, these scalar products can be expressed as some determinants with a non-trivial dependance in terms of the inhomogeneity parameters that have to be introduced for the method to be applicable. We show that these determinants can be transformed into alternative ones in which the homogeneous limit can easily be taken. These new representations can be considered as generalizations of the well-known determinant representation for the scalar products of the Bethe states of the periodic chain. In the particular case where a constraint is applied on the boundary parameters, such that the transfer matrix spectrum and eigenstates can be characterized in terms of polynomial solutions of a usual T-Q equation, the scalar product that we compute here corresponds to the scalar product between two off-shell Bethe-type states. If in addition one of the states is an eigenstate, the determinant representation can be simplified, hence leading in this boundary case to direct analogues of algebraic Bethe ansatz determinant representations of the scalar products for the periodic chain.

The open XXX spin chain in the SoV framework: scalar product of separate states

International Nuclear Information System (INIS)

Kitanine, N; Maillet, J M; Niccoli, G; Terras, V

2017-01-01

We consider the XXX open spin-1/2 chain with the most general non-diagonal boundary terms, that we solve by means of the quantum separation of variables (SoV) approach. We compute the scalar products of separate states, a class of states which notably contains all the eigenstates of the model. As usual for models solved by SoV, these scalar products can be expressed as some determinants with a non-trivial dependance in terms of the inhomogeneity parameters that have to be introduced for the method to be applicable. We show that these determinants can be transformed into alternative ones in which the homogeneous limit can easily be taken. These new representations can be considered as generalizations of the well-known determinant representation for the scalar products of the Bethe states of the periodic chain. In the particular case where a constraint is applied on the boundary parameters, such that the transfer matrix spectrum and eigenstates can be characterized in terms of polynomial solutions of a usual T - Q equation, the scalar product that we compute here corresponds to the scalar product between two off-shell Bethe-type states. If in addition one of the states is an eigenstate, the determinant representation can be simplified, hence leading in this boundary case to direct analogues of algebraic Bethe ansatz determinant representations of the scalar products for the periodic chain. (paper)

SPIN SELLING CONCEPT & ITS APPLICATION IN THE BUSINESS PERFORMANCE OF SACHET PRODUCT IN BANGLADESH

Directory of Open Access Journals (Sweden)

Mir Hossain SOHEL

2016-06-01

Full Text Available Bangladesh is lower middle income oriented country (LMIC in South Asia where sachet product has become more popular than other scaling products. SPIN selling is an approach of consultative selling or presenting an offer to the potential clients considering their pain-points using a powerful questioning process. This study attempts to find out the reasons of gaining popularity of sachet product in Bangladesh. SPIN Selling concept is the age-old concept used in this respect. A sample size of 120 was collected from the salespeople of 15 different companies that are co-integrated sachet product in their product line. A self-administered questionnaire is applied for data collection and This study reveals hat the existence of the applicability of SPIN concept in a moderate format in Bangladesh. The findings of the study postulate that in Bangladesh, sachet product is introduced as follower product and it will be helpful for the marketing executives, R&D officers or decision makers of concerned firms in re-considering their strategic thinking aiming to gain sustainable competitive advantage in the product market of Bangladesh for sachet product.

TMRG studies on spin alignment in molecule-based ferrimagnetics [rapid communication

Science.gov (United States)

Liu, Q. M.; Yao, K. L.; Liu, Z. L.

2005-05-01

A physical picture of spin alignment in organic molecule-based ferrimagnets is presented from studying the thermal effective magnetic moment of the sublattice by use of the transfer matrix renormalization group. We conclude that the classical antiparallel spin alignment is not the most stable state. The three-spin system tends to parallel alignment when the exchange interaction between the biradical and the monoradical molecules is much weaker than that within the biradical, which can result in the decrease of the effective magnetic moment upon lowering the temperature. More importantly, we give the theoretical evidence that even the antiparallel spin alignment in the biradical monoradical alternating chain does not necessarily lead to ferrimagnetic spin ordering due to the formation of the spin singlet pairs, which suppresses the ferrimagnetic spin alignment.

On higher-spin supertranslations and superrotations

Energy Technology Data Exchange (ETDEWEB)

Campoleoni, Andrea [Université Libre de Bruxelles and International Solvay Institutes,ULB-Campus Plaine CP231, B-1050 Brussels (Belgium); Francia, Dario; Heissenberg, Carlo [Scuola Normale Superiore and INFN,Piazza dei Cavalieri 7, I-56126 Pisa (Italy)

2017-05-22

We study the large gauge transformations of massless higher-spin fields in four-dimensional Minkowski space. Upon imposing suitable fall-off conditions, providing higher-spin counterparts of the Bondi gauge, we observe the existence of an infinite-dimensional asymptotic symmetry algebra. The corresponding Ward identities can be held responsible for Weinberg’s factorisation theorem for amplitudes involving soft particles of spin greater than two.

Entangled spins and ghost-spins

Directory of Open Access Journals (Sweden)

Dileep P. Jatkar

2017-09-01

Full Text Available We study patterns of quantum entanglement in systems of spins and ghost-spins regarding them as simple quantum mechanical toy models for theories containing negative norm states. We define a single ghost-spin as in [20] as a 2-state spin variable with an indefinite inner product in the state space. We find that whenever the spin sector is disentangled from the ghost-spin sector (both of which could be entangled within themselves, the reduced density matrix obtained by tracing over all the ghost-spins gives rise to positive entanglement entropy for positive norm states, while negative norm states have an entanglement entropy with a negative real part and a constant imaginary part. However when the spins are entangled with the ghost-spins, there are new entanglement patterns in general. For systems where the number of ghost-spins is even, it is possible to find subsectors of the Hilbert space where positive norm states always lead to positive entanglement entropy after tracing over the ghost-spins. With an odd number of ghost-spins however, we find that there always exist positive norm states with negative real part for entanglement entropy after tracing over the ghost-spins.

Improving Innovation in University Spin-Offs. The Fostering Role of University and Region

Directory of Open Access Journals (Sweden)

Antonio Prencipe

2016-06-01

Full Text Available University spin-offs (USOs are companies created to commercialize knowledge or technology developed in academia; thus, their major contribution to the knowledge economy is their ability to generate innovation. Following the Resource-Based View of the Firm and the Knowledge Spillover Theory of Entrepreneurship, it was stated that fostering mechanisms at university level and at regional level may positively influence the USOs innovation. Based on a sample of 621 Italian USOs, we show that the positive impact of the university context is more crucial compared with those of the regional context. In particular, the university affiliated business incubators and Science Parks, jointly with the university financial resources, seem to promote the innovation efforts of USOs. These evidences rise the need of a resilient partnership among all the contextual players involved in the spillover processes, mainly at regional level, in order to effectively exploit the potential innovative efforts of the university start-ups.

Methyldibromoglutaronitrile in rinse-off products causes allergic contact dermatitis

DEFF Research Database (Denmark)

Jensen, C D; Johansen, J D; Menné, T

2004-01-01

BACKGROUND: The frequency of sensitivity to the cosmetic preservative methyldibromoglutaronitrile (MDBGN) has increased significantly in Europe. Most cases of allergic contact dermatitis from MDBGN are caused by leave-on cosmetic products. The risk of developing allergic contact dermatitis from...... series of MDBGN to determine their patch test threshold values. RESULTS: Seven presensitized individuals (37%) developed allergic contact dermatitis from the soap containing MDBGN. The mean dose of MDBGN per application was 2.2 micro g cm-2 and the reactions appeared between days 6 and 34. All nine...... rinse-off products has been less studied. OBJECTIVES: To investigate the allergic response elicited in presensitized individuals from exposure to a rinse-off product preserved with the maximum permitted level of MDBGN. METHODS: Nineteen contact allergic individuals and nine controls participated...

Transverse target spin asymmetries in exclusive $\\rho^0$ muoproduction

CERN Document Server

Adolph, C; Alexakhin, V Yu; Alexandrov, Yu; Alexeev, G D; Amoroso, A; Andrieux, V; Austregesilo, A; Badelek, B; Balestra, F; Barth, J; Baum, G; Bedfer, Y; Berlin, A; Bernhard, J; Bertini, R; Bicker, K; Bieling, J; Birsa, R; Bisplinghoff, J; Boer, M; Bordalo, P; Bradamante, F; Braun, C; Bravar, A; Bressan, A; Büchele, M; Burtin, E; Capozza, L; Chiosso, M; Chung, S U; Cicuttin, A; Crespo, M L; Dalla Torre, S; Dasgupta, S S; Dasgupta, S; Denisov, O Yu; Donskov, S V; Doshita, N; Duic, V; Dünnweber, W; Dziewiecki, M; Efremov, A; Elia, C; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Filin, A; Finger, M; Finger, M jr; Fischer, H; Franco, C; du Fresne von Hohenesche, N; Friedrich, J M; Frolov, V; Garfagnini, R; Gautheron, F; Gavrichtchouk, O P; Gerassimov, S; Geyer, R; Giorgi, M; Gnesi, I; Gobbo, B; Goertz, S; Grabmüller, S; Grasso, A; Grube, B; Gushterski, R; Guskov, A; Guthörl, T; Haas, F; von Harrach, D; Hahne, D; Heinsius, F H; Herrmann, F; Hess, C; Hinterberger, F; Höppner, Ch; Horikawa, N; d'Hose, N; Huber, S; Ishimoto, S; Ivanshin, Yu; Iwata, T; Jahn, R; Jary, V; Jasinski, P; Joosten, R; Kabuss, E; Kang, D; Ketzer, B; Khaustov, G V; Khokhlov, Yu A; Kisselev, Yu; Klein, F; Klimaszewski, K; Koivuniemi, J H; Kolosov, V N; Kondo, K; Königsmann, K; Konorov, I; Konstantinov, V F; Kotzinian, A M; Kouznetsov, O; Krämer, M; Kroumchtein, Z V; Kuchinski, N; Kunne, F; Kurek, K; Kurjata, R P; Lednev, A A; Lehmann, A; Levorato, S; Lichtenstadt, J; Maggiora, A; Magnon, A; Makke, N; Mallot, G K; Marchand, C; Martin, A; Marzec, J; Matousek, J; Matsuda, H; Matsuda, T; Meshcheryakov, G; Meyer, W; Michigami, T; Mikhailov, Yu V; Miyachi, Y; Morreale, A; Nagaytsev, A; Nagel, T; Nerling, F; Neubert, S; Neyret, D; Nikolaenko, V I; Novy, J; Nowak, W D; Nunes, A.S; Olshevsky, A G; Ostrick, M; Panknin, R; Panzieri, D; Parsamyan, B; Paul, S; Pesek, M; Piragino, G; Platchkov, S; Pochodzalla, J; Polak, J; Polyakov, V A; Pretz, J; Quaresma, M; Quintans, C; Ramos, S; Reicherz, G; Rocco, E; Rodionov, V; Rondio, E; Rossiyskaya, N S; Ryabchikov, D I; Samoylenko, V D; Sandacz, A; Sapozhnikov, M G; Sarkar, S; Savin, I A; Sbrizzai, G; Schiavon, P; Schill, C; Schlüter, T; Schmidt, A; Schmidt, K; Schmitt, L; Schmïden, H; Schönning, K; Schopferer, S; Schott, M; Shevchenko, O Yu; Silva, L; Sinha, L; Sirtl, S; Slunecka, M; Sosio, S; Sozzi, F; Srnka, A; Steiger, L; Stolarski, M; Sulc, M; Sulej, R; Suzuki, H; Sznajder, P; Takekawa, S; Ter Wolbeek, J; Tessaro, S; Tessarotto, F; Thibaud, F; Uhl, S; Uman, I; Vandenbroucke, M; Virius, M; Vondra, J; Wang, L; Weisrock, T; Wilfert, M; Windmolders, R; Wislicki, W; Wollny, H; Zaremba, K; Zavertyaev, M; Zemlyanichkina, E; Zhuravlev, N; Ziembicki, M

2014-01-01

Exclusive production of $\\rho^0$ mesons was studied at the COMPASS experiment by scattering 160 GeV/$c$ muons off transversely polarised protons. Five single-spin and three double-spin azimuthal asymmetries were measured as a function of $Q^2$, $x_{Bj}$, or $p_{T}^{2}$. The $\\sin \\phi_S$ asymmetry is found to be $-0.019 \\pm 0.008(stat.) \\pm 0.003(syst.)$. All other asymmetries are also found to be of small magnitude and consistent with zero within experimental uncertainties. Very recent calculations using a GPD-based model agree well with the present results. The data is interpreted as evidence for the existence of chiral-odd, transverse generalized parton distributions.

Diagnostic accuracy of dynamic contrast-enhanced MR imaging of renal masses with rapid-acquisition spin-echo technique

International Nuclear Information System (INIS)

Eilenberg, S.S.; Lee, J.K.T.; Brown, J.J.; Heiken, J.P.; Mirowitz, S.A.

1990-01-01

This paper compares the diagnostic accuracy of Gd-DTPA-enhanced rapid-acquisition spin-echo (RASE) imaging with standard spin-echo techniques for detecting renal cysts and solid renal neoplasms. RASE imaging combines a short TR (275 msec)/short TE (10 msec), single excitation pulse sequence with half-Fourier data sampling. Eighteen patients with CT evidence of renal masses were first evaluated with standard T1-and T2-weighted SE sequences. Pre- and serial postcontrast (Cd-DTPA, 0.1 mmol./kg) RASE sequences were then performed during suspended respiration. A final set of postcontrast images was obtained with the standard T1-weighted SE sequence. Each set of MR images was first reviewed separately (ie, T1, T2, pre- and post-contrast RASE, etc)

Off-Line Testing of Tribo-Systems for Sheet Metal Forming Production

DEFF Research Database (Denmark)

Bay, Niels; Ceron, Ermanno

2014-01-01

Off-line testing of new tribo-systems for sheet metal forming production is an important issue, when new, environmentally benign lubricants are to be introduced. To obtain useful results it is, however, vital to ensure similar conditions as in the production process regarding the main tribo...... leading to very high tool/workpiece interface pressure and temperature in the second re-draw. Under such conditions only the best lubricant systems work satisfactory, and the paper shows how the performance of different tribo-systems in production may be predicted by off-line testing combined...

The Production of Material with Ultrafine Grain Structure in Al-Zn Alloy in the Process of Rapid Solidification

Directory of Open Access Journals (Sweden)

Szymaneka M.

2014-06-01

Full Text Available In the aluminium alloy family, Al-Zn materials with non-standard chemical composition containing Mg and Cu are a new group of alloys, mainly owing to their high strength properties. Proper choice of alloying elements, and of the method of molten metal treatment and casting enable further shaping of the properties. One of the modern methods to produce materials with submicron structure is a method of Rapid Solidification. The ribbon cast in a melt spinning device is an intermediate product for further plastic working. Using the technique of Rapid Solidification it is not possible to directly produce a solid structural material of the required shape and length. Therefore, the ribbon of an ultrafine grain or nanometric structure must be subjected to the operations of fragmentation, compaction, consolidation and hot extrusion.

JINR rapid communications

International Nuclear Information System (INIS)

1995-01-01

The present collection of rapid communications from JINR, Dubna, contains eight separate reports on the measurement of charge radii for Ti nuclei, spectroscopy of 13 Be, concentrations of hadrons and quark-gluon plasma in mixed phase, experimental results on one-spin pion asymmetry in the d↑ + A → π±(90 0 ) + X process, new results on cumulative pion and proton production in p-D collisions, investigation of charge exchange reactions, the study of the tensor analyzing power in cumulative particle production on a deuteron beam and an evidence for the excited states of the S = -2 stable light dibaryon. 32 figs., 6 tabs

Summary of the 9th international symposium on high energy spin-physics

International Nuclear Information System (INIS)

Prescott, C.Y.

1990-11-01

Summarizing an international conference in high energy spin physics is never an easy task, because of the wide-ranging subjects in physics and technology that are involved. I have chosen to organize the topics of this conference into three broad categories relating to spin; intrinsic spin; composite spin; and spin, the experimental tool. In the first category, I will briefly revisit some historical and recent developments to set a background. In the second category, composite spin, I will discuss the status and developments in several areas, including magnetic moments of baryons, hyperon polarization in high energy high p perpendicular production, transverse polarization and asymmetries from transversely polarized targets in high p perpendicular scattering, spin structure of the proton, and the Bjorken sum rule. In the third category, I will discuss the steady, and at times rapid, progress in spin technology. In this part I include recent progress in high energy facilities, and comment on the highlights of the Workshops

On the semi-classical limit of scalar products of the XXZ spin chain

Energy Technology Data Exchange (ETDEWEB)

Jiang, Yunfeng; Brunekreef, Joren [Institut für Theoretische Physik, ETH Zürich,Wolfgang Pauli Strasse 27, CH-8093 Zürich (Switzerland)

2017-03-03

We study the scalar products between Bethe states in the XXZ spin chain with anisotropy |Δ|>1 in the semi-classical limit where the length of the spin chain and the number of magnons tend to infinity with their ratio kept finite and fixed. Our method is a natural yet non-trivial generalization of similar methods developed for the XXX spin chain. The final result can be written in a compact form as a contour integral in terms of Faddeev’s quantum dilogarithm function, which in the isotropic limit reduces to the classical dilogarithm function.

On the semi-classical limit of scalar products of the XXZ spin chain

International Nuclear Information System (INIS)

Jiang, Yunfeng; Brunekreef, Joren

2017-01-01

We study the scalar products between Bethe states in the XXZ spin chain with anisotropy |Δ|>1 in the semi-classical limit where the length of the spin chain and the number of magnons tend to infinity with their ratio kept finite and fixed. Our method is a natural yet non-trivial generalization of similar methods developed for the XXX spin chain. The final result can be written in a compact form as a contour integral in terms of Faddeev’s quantum dilogarithm function, which in the isotropic limit reduces to the classical dilogarithm function.

Electric dipole spin resonance in a quantum spin dimer system driven by magnetoelectric coupling

Science.gov (United States)

Kimura, Shojiro; Matsumoto, Masashige; Akaki, Mitsuru; Hagiwara, Masayuki; Kindo, Koichi; Tanaka, Hidekazu

2018-04-01

In this Rapid Communication, we propose a mechanism for electric dipole active spin resonance caused by spin-dependent electric polarization in a quantum spin gapped system. This proposal was successfully confirmed by high-frequency electron spin resonance (ESR) measurements of the quantum spin dimer system KCuCl3. ESR measurements by an illuminating linearly polarized electromagnetic wave reveal that the optical transition between the singlet and triplet states in KCuCl3 is driven by an ac electric field. The selection rule of the observed transition agrees with the calculation by taking into account spin-dependent electric polarization. We suggest that spin-dependent electric polarization is effective in achieving fast control of quantum spins by an ac electric field.

Exclusive meson production at COMPASS

CERN Document Server

Pochodzalla, Josef; Moinester, Murray; Piller, Gunther; Sandacz, Andrzej; Vanderhaeghen, Marc; Pochodzalla, Josef; Mankiewicz, Lech; Moinester, Murray; Piller, Gunther; Sandacz, Andrzej; Vanderhaeghen, Marc

1999-01-01

We explore the feasibility to study exclusive meson production (EMP) in hard muon-proton scattering at the COMPASS experiment. These measurements constrain the off-forward parton distributions (OFPD's) of the proton, which are related to the quark orbital contribution to the proton spin.

Efficient eigenvalue determination for arbitrary Pauli products based on generalized spin-spin interactions

Science.gov (United States)

Leibfried, D.; Wineland, D. J.

2018-03-01

Effective spin-spin interactions between ? qubits enable the determination of the eigenvalue of an arbitrary Pauli product of dimension N with a constant, small number of multi-qubit gates that is independent of N and encodes the eigenvalue in the measurement basis states of an extra ancilla qubit. Such interactions are available whenever qubits can be coupled to a shared harmonic oscillator, a situation that can be realized in many physical qubit implementations. For example, suitable interactions have already been realized for up to 14 qubits in ion traps. It should be possible to implement stabilizer codes for quantum error correction with a constant number of multi-qubit gates, in contrast to typical constructions with a number of two-qubit gates that increases as a function of N. The special case of finding the parity of N qubits only requires a small number of operations that is independent of N. This compares favorably to algorithms for computing the parity on conventional machines, which implies a genuine quantum advantage.

Transverse Spin Physics: Recent Developments

International Nuclear Information System (INIS)

Yuan, Feng

2008-01-01

Transverse-spin physics has been very active and rapidly developing in the last few years. In this talk, I will briefly summarize recent theoretical developments, focusing on the associated QCD dynamics in transverse spin physics

AN ENERGETIC AGN OUTBURST POWERED BY A RAPIDLY SPINNING SUPERMASSIVE BLACK HOLE OR AN ACCRETING ULTRAMASSIVE BLACK HOLE

International Nuclear Information System (INIS)

McNamara, B. R.; Kazemzadeh, F.; Kirkpatrick, C. C.; Rafferty, D. A.; Birzan, L.; Nulsen, P. E. J.; Wise, M. W.

2009-01-01

Powering the 10 62 erg nuclear outburst in the MS0735.6+7421 cluster central galaxy by accretion with a 10% mass-to-energy conversion efficiency implies that its putative supermassive black hole (SMBH) grew by ∼6 x 10 8 M sun over the past 100 Myr. Guided by data at several wavelengths, we place upper limits on the amount of cold gas and star formation near the nucleus of 9 M sun and sun yr -1 , respectively. These limits imply that an implausibly large fraction of the preexisting cold gas in the inner several kpc must have been consumed by its SMBH at the rate of ∼3-5 M sun yr -1 during the past 100 Myr while leaving no trace of star formation. Such a high accretion rate would be difficult to maintain by stellar accretion or the Bondi mechanism, unless the black hole mass approaches 10 11 M sun . Furthermore, its feeble nuclear luminosities in the UV, I, and X-ray bands compared to its enormous mechanical power are inconsistent with rapid accretion onto a ∼5 x 10 9 M sun black hole. We suggest instead that the active galactic nucleus (AGN) outburst is powered by angular momentum released from a rapidly spinning black hole. The rotational energy and power available from a spinning black hole are consistent with the cavity and shock energetics inferred from X-ray observations. A maximally spinning 10 9 M sun black hole contains enough rotational energy, ∼10 62 erg, to quench a cooling flow over its lifetime and to contribute significantly to the excess entropy found in the hot atmospheres of groups and clusters. Two modes of AGN feedback may be quenching star formation in elliptical galaxies centered in cooling halos at late times. An accretion mode that operates in gas-rich systems, and a spin mode operating at modest accretion rates. The spin conjecture may be avoided in MS0735 by appealing to Bondi accretion onto a central black hole whose mass greatly exceeds 10 10 M sun . The host galaxy's unusually large 3.8 kpc stellar core radius (light deficit) may

Measurement of Spin Correlation in Top Quark Pair Production at ATLAS

CERN Document Server

McLaughlan, Thomas

2014-01-01

This thesis presents a study of spin correlation in tt ̄ production in the ATLAS detector, in proton-proton collisions, corresponding to an integrated luminosity of 4.7 fb$^{−1}$, with a centre of mass energy of $\\sqrt{s}$ = 7 TeV. Both the dilepton and single lepton channels are considered, the latter providing a greater challenge due to the neccessity to reconstruct the down-type quark resulting from the W boson decay. A simple technique is employed to reconstruct single lepton $t\\bar{t}$ events, with the transverse angle between the charged lepton and down-type quark used as a probe of the spin correlation. In the dilepton channel, the transverse angle between both charged leptons is used. The extracted value of spin correlation in each channel is consistent with Standard Model predictions, with the result in the eμ channel alone sufficient to exclude a model without spin correlation at 7.8$\\sigma$. Also described is the author’s contribution to the maintenance and development of the Atlantis Event D...

Spinning out a star.

Science.gov (United States)

Lord, Michael D; Mandel, Stanley W; Wager, Jeffrey D

2002-06-01

Spinouts rarely take off; most, in fact, fall into one or more of four traps that doom them from the start. Some companies spin out ventures that are too close to the core of their businesses, in effect selling off their crown jewels. Sometimes, a parent company uses the spinout primarily to pawn off debt or expenses or to quickly raise external capital for itself. Other times, a company may try to spin out an area of its business that lacks one or more of the critical legs of a successful company--a coherent business model, say, or a solid financial base. And in many cases, parent companies can't bring themselves to sever their ownership ties and give up control of their spinouts. R.J. Reynolds, the tobacco giant, managed to avoid these traps when it successfully spun out a most unlikely venture, the pharmaceutical company Targacept. As the story illustrates, the problem with spinouts is similar to the problem of rich children. Their parents have the wherewithal to spoil them or shelter them or cling to them, but what they need is tough love and discipline--much the same discipline that characterizes successful start-ups. R.J. Reynolds recognized that it didn't know that much about the pharmaceutical business and couldn't merely try to spin out a small clone of itself. It had to treat the venture as if it were essentially starting from scratch, with a passionate entrepreneurial leader, a solid business plan, help from outside partners in the industry, and ultimately substantial venture backing. That these lessons are less obvious to executives contemplating spinning out ventures closer to their core businesses may be why so many spinouts fail.

Measuring azimuthal asymmetries in semi-inclusive deep-inelastic scattering off transversely polarized protons

CERN Document Server

Wollny, Heiner

2010-01-01

The COMPASS experiment at the international research center CERN (European Organization for Nuclear Research) is dedicated to study the longitudinal and transverse spin structure of the nucleon. It is a fixed target experiment at the end of the M2 beam line of the SPS accelerator, which provides a 160 GeV/c longitudinally polarized muon beam. In the years 2002, 2003, 2004 and 2006 COMPASS took data scattering off polarized deuterons and in the year 2007 scattering off polarized protons. The analysis of the data taken in 2007 with transversely polarized protons is the topic of this thesis. In leading order and integrating over quark transverse momenta three parton distribution functions are needed for a complete description of the nucleon. Two of them, the quark number density and the helicity distribution are well known. However, the third one, the transversity distribution is up to now almost unknown. In this thesis single spin asymmetries in the cross-section of one hadron and two hadron production are anal...

Single spin asymmetries in charged kaon production from semi-inclusive deep inelastic scattering on a transversely polarized 3He target

Science.gov (United States)

Zhao, Y. X.; Wang, Y.; Allada, K.; Aniol, K.; Annand, J. R. M.; Averett, T.; Benmokhtar, F.; Bertozzi, W.; Bradshaw, P. C.; Bosted, P.; Camsonne, A.; Canan, M.; Cates, G. D.; Chen, C.; Chen, J.-P.; Chen, W.; Chirapatpimol, K.; Chudakov, E.; Cisbani, E.; Cornejo, J. C.; Cusanno, F.; Dalton, M. M.; Deconinck, W.; de Jager, C. W.; De Leo, R.; Deng, X.; Deur, A.; Ding, H.; Dolph, P. A. M.; Dutta, C.; Dutta, D.; El Fassi, L.; Frullani, S.; Gao, H.; Garibaldi, F.; Gaskell, D.; Gilad, S.; Gilman, R.; Glamazdin, O.; Golge, S.; Guo, L.; Hamilton, D.; Hansen, O.; Higinbotham, D. W.; Holmstrom, T.; Huang, J.; Huang, M.; Ibrahim, H. F.; Iodice, M.; Jiang, X.; Jin, G.; Jones, M. K.; Katich, J.; Kelleher, A.; Kim, W.; Kolarkar, A.; Korsch, W.; LeRose, J. J.; Li, X.; Li, Y.; Lindgren, R.; Liyanage, N.; Long, E.; Lu, H.-J.; Margaziotis, D. J.; Markowitz, P.; Marrone, S.; McNulty, D.; Meziani, Z.-E.; Michaels, R.; Moffit, B.; Muñoz Camacho, C.; Nanda, S.; Narayan, A.; Nelyubin, V.; Norum, B.; Oh, Y.; Osipenko, M.; Parno, D.; Peng, J.-C.; Phillips, S. K.; Posik, M.; Puckett, A. J. R.; Qian, X.; Qiang, Y.; Rakhman, A.; Ransome, R.; Riordan, S.; Saha, A.; Sawatzky, B.; Schulte, E.; Shahinyan, A.; Shabestari, M. H.; Širca, S.; Stepanyan, S.; Subedi, R.; Sulkosky, V.; Tang, L.-G.; Tobias, A.; Urciuoli, G. M.; Vilardi, I.; Wang, K.; Wojtsekhowski, B.; Yan, X.; Yao, H.; Ye, Y.; Ye, Z.; Yuan, L.; Zhan, X.; Zhang, Y.; Zhang, Y.-W.; Zhao, B.; Zheng, X.; Zhu, L.; Zhu, X.; Zong, X.; Jefferson Lab Hall A Collaboration

2014-11-01

We report the first measurement of target single spin asymmetries of charged kaons produced in semi-inclusive deep inelastic scattering of electrons off a transversely polarized 3He target. Both the Collins and Sivers moments, which are related to the nucleon transversity and Sivers distributions, respectively, are extracted over the kinematic range of 0.1 production. While the Collins and Sivers moments for K+ are consistent with zero within the experimental uncertainties, both moments for K- favor negative values. The Sivers moments are compared to the theoretical prediction from a phenomenological fit to the world data. While the K+ Sivers moments are consistent with the prediction, the K- results differ from the prediction at the 2-sigma level.

FERMILAB: High energy spin effects

Energy Technology Data Exchange (ETDEWEB)

Anon.

1991-03-15

While many physicists would agree that it is important to study interactions of different isospin states (for example comparing proton and neutron data), many of them also accept as normal data averaged or integrated over ordinary spin. However an ongoing programme at Brookhaven studying elastic scattering (where the incoming particles 'bounce' off each other) produced marked spin effects which are not well understood. Our understanding of particle interactions should not be influenced by which observables are easy to measure and which aren't, and until a clear understanding of spin effects emerges, it is important to continue and extend these studies.

Spin Correlations of Lambda anti-Lambda Pairs as a Probe of Quark-Antiquark Pair Production

CERN Document Server

Ellis, John

2012-01-01

The polarizations of Lambda and anti-Lambda are thought to retain memories of the spins of their parent s quarks and antiquarks, and are readily measurable via the angular distributions of their daughter protons and antiprotons. Correlations between the spins of Lambda and anti-Lambda produced at low relative momenta may therefore be used to probe the spin states of s anti-s pairs produced during hadronization. We consider the possibilities that they are produced in a 3P_0 state, as might result from fluctuations in the magnitude of , a 1S_0 state, as might result from chiral fluctuations, or a 3S_1 or other spin state, as might result from production by a quark-antiquark or gluon pair. We provide templates for the p anti-p angular correlations that would be expected in each of these cases, and discuss how they might be used to distinguish s anti-s production mechanisms in pp and heavy-ion collisions.

Performance comparison of dynamical decoupling sequences for a qubit in a rapidly fluctuating spin bath

International Nuclear Information System (INIS)

Alvarez, Gonzalo A.; Suter, Dieter; Ajoy, Ashok; Peng Xinhua

2010-01-01

Avoiding the loss of coherence of quantum mechanical states is an important prerequisite for quantum information processing. Dynamical decoupling (DD) is one of the most effective experimental methods for maintaining coherence, especially when one can access only the qubit system and not its environment (bath). It involves the application of pulses to the system whose net effect is a reversal of the system-environment interaction. In any real system, however, the environment is not static, and therefore the reversal of the system-environment interaction becomes imperfect if the spacing between refocusing pulses becomes comparable to or longer than the correlation time of the environment. The efficiency of the refocusing improves therefore if the spacing between the pulses is reduced. Here, we quantify the efficiency of different DD sequences in preserving different quantum states. We use 13 C nuclear spins as qubits and an environment of 1 H nuclear spins as the environment, which couples to the qubit via magnetic dipole-dipole couplings. Strong dipole-dipole couplings between the proton spins result in a rapidly fluctuating environment with a correlation time of the order of 100 μs. Our experimental results show that short delays between the pulses yield better performance if they are compared with the bath correlation time. However, as the pulse spacing becomes shorter than the bath correlation time, an optimum is reached. For even shorter delays, the pulse imperfections dominate over the decoherence losses and cause the quantum state to decay.

Solar photochemical production of HBr for off-peak electrolytic hydrogen production

Energy Technology Data Exchange (ETDEWEB)

Heaton, H. [Solar Reactor Technologies Inc., Miami, FL (United States)

1996-10-01

Progress is reported on the development of a unique and innovative hydrogen production concept utilizing renewable (Solar) energy and incorporating energy storage. The concept is based on a solar-electrolytic system for production of hydrogen and oxygen. It employs water, bromine, solar energy, and supplemental electrical power. The process consumes only water, sunlight and off-peak electricity, and produces only hydrogen, oxygen, and peaking electrical power. No pollutants are emitted, and fossil fuels are not consumed. The concept is being developed by Solar Reactor Technologies, Inc., (SRT) under the auspices of a Cooperative Agreement with the U.S. Department of Energy (DOE).

The role of off-line and online strategies for successful product positioning

OpenAIRE

Yaneva D. E.; Zlateva D. A.

2015-01-01

The study of the article is done on off-line and online strategies that companies use for their successful positioning. The goal is to establish the role and the significance of the strategies for successful product positioning in off-line and online environment.

Product operator descriptions of INEPT and RINEPT NMR spectroscopies for ISn ( I=1/2, S=3/2) spin systems

Science.gov (United States)

Tokatlı, Ahmet; Gençten, Azmi; Şahin, Mükerrem; Tezel, Özden; Bahçeli, Semiha

2004-07-01

The product operator descriptions of INEPT and reverse INEPT (RINEPT) NMR experiments are introduced for weakly coupled ISn ( I=1/2, S=3/2 with n=1,2,3) spin systems. Explicit expressions for polarization transfer from spin-3/2 quadrupolar nuclei to spin-1/2 nuclei (and reversed polarization transfer) are given in detail by using the evolutions of product operators under the spin-spin coupling Hamiltonian. The results calculated for the intensities and positions of the observable signals are simulated in the molecules containning the 119Sn ( I=1/2) and 35Cl ( S=3/2) nuclei at the coupling constant of JSn-Cl=375 Hz by using the Maple programme on computer.

Sign rules for anisotropic quantum spin systems

International Nuclear Information System (INIS)

Bishop, R. F.; Farnell, D. J. J.; Parkinson, J. B.

2000-01-01

We present exact ''sign rules'' for various spin-s anisotropic spin-lattice models. It is shown that, after a simple transformation which utilizes these sign rules, the ground-state wave function of the transformed Hamiltonian is positive definite. Using these results exact statements for various expectation values of off-diagonal operators are presented, and transitions in the behavior of these expectation values are observed at particular values of the anisotropy. Furthermore, the importance of such sign rules in variational calculations and quantum Monte Carlo calculations is emphasized. This is illustrated by a simple variational treatment of a one-dimensional anisotropic spin model

RECOILING SUPERMASSIVE BLACK HOLES IN SPIN-FLIP RADIO GALAXIES

International Nuclear Information System (INIS)

Liu, F. K.; Wang Dong; Chen Xian

2012-01-01

Numerical relativity simulations predict that coalescence of supermassive black hole (SMBH) binaries leads not only to a spin flip but also to a recoiling of the merger remnant SMBHs. In the literature, X-shaped radio sources are popularly suggested to be candidates for SMBH mergers with spin flip of jet-ejecting SMBHs. Here we investigate the spectral and spatial observational signatures of the recoiling SMBHs in radio sources undergoing black hole spin flip. Our results show that SMBHs in most spin-flip radio sources have mass ratio q ∼> 0.3 with a minimum possible value q min ≅ 0.05. For major mergers, the remnant SMBHs can get a kick velocity as high as 2100 km s –1 in the direction within an angle ∼< 40° relative to the spin axes of remnant SMBHs, implying that recoiling quasars are biased to be with high Doppler-shifted broad emission lines while recoiling radio galaxies are biased to large apparent spatial off-center displacements. We also calculate the distribution functions of line-of-sight velocity and apparent spatial off-center displacements for spin-flip radio sources with different apparent jet reorientation angles. Our results show that the larger the apparent jet reorientation angle is, the larger the Doppler-shifting recoiling velocity and apparent spatial off-center displacement will be. We investigate the effects of recoiling velocity on the dust torus in spin-flip radio sources and suggest that recoiling of SMBHs would lead to 'dust-poor' active galactic nuclei. Finally, we collect a sample of 19 X-shaped radio objects and for each object give the probability of detecting the predicted signatures of recoiling SMBH.

Rapid communication: Transverse spin with coupled plasmons

Indian Academy of Sciences (India)

Samyobrata Mukherjee

2017-07-25

Jul 25, 2017 ... spline interpolation from the data of Johnson and Christy. [31]. But first, we have to deal with normalization in order to make our comparisons of the transverse spin for different wavelengths and metal film thicknesses d meaningful. We normalize the power flow into the sys- tem at x = 0 to unity. ∫ ∞. −∞.

Non-exponential decoherence of radio-frequency resonance rotation of spin in storage rings

Science.gov (United States)

Saleev, A.; Nikolaev, N. N.; Rathmann, F.; Hinder, F.; Pretz, J.; Rosenthal, M.

2017-08-01

Precision experiments, such as the search for electric dipole moments of charged particles using radio-frequency spin rotators in storage rings, demand for maintaining the exact spin resonance condition for several thousand seconds. Synchrotron oscillations in the stored beam modulate the spin tune of off-central particles, moving it off the perfect resonance condition set for central particles on the reference orbit. Here, we report an analytic description of how synchrotron oscillations lead to non-exponential decoherence of the radio-frequency resonance driven up-down spin rotations. This non-exponential decoherence is shown to be accompanied by a nontrivial walk of the spin phase. We also comment on sensitivity of the decoherence rate to the harmonics of the radio-frequency spin rotator and a possibility to check predictions of decoherence-free magic energies.

Off-Diagonal Geometric Phase in a Neutron Interferometer Experiment

International Nuclear Information System (INIS)

Hasegawa, Y.; Loidl, R.; Baron, M.; Badurek, G.; Rauch, H.

2001-01-01

Off-diagonal geometric phases acquired by an evolution of a 1/2 -spin system have been observed by means of a polarized neutron interferometer. We have successfully measured the off-diagonal phase for noncyclic evolutions even when the diagonal geometric phase is undefined. Our data confirm theoretical predictions and the results illustrate the significance of the off-diagonal phase

Optical hyperpolarization of 13C nuclear spins in nanodiamond ensembles

Science.gov (United States)

Chen, Q.; Schwarz, I.; Jelezko, F.; Retzker, A.; Plenio, M. B.

2015-11-01

Dynamical nuclear polarization holds the key for orders of magnitude enhancements of nuclear magnetic resonance signals which, in turn, would enable a wide range of novel applications in biomedical sciences. However, current implementations of DNP require cryogenic temperatures and long times for achieving high polarization. Here we propose and analyze in detail protocols that can achieve rapid hyperpolarization of 13C nuclear spins in randomly oriented ensembles of nanodiamonds at room temperature. Our protocols exploit a combination of optical polarization of electron spins in nitrogen-vacancy centers and the transfer of this polarization to 13C nuclei by means of microwave control to overcome the severe challenges that are posed by the random orientation of the nanodiamonds and their nitrogen-vacancy centers. Specifically, these random orientations result in exceedingly large energy variations of the electron spin levels that render the polarization and coherent control of the nitrogen-vacancy center electron spins as well as the control of their coherent interaction with the surrounding 13C nuclear spins highly inefficient. We address these challenges by a combination of an off-resonant microwave double resonance scheme in conjunction with a realization of the integrated solid effect which, together with adiabatic rotations of external magnetic fields or rotations of nanodiamonds, leads to a protocol that achieves high levels of hyperpolarization of the entire nuclear-spin bath in a randomly oriented ensemble of nanodiamonds even at room temperature. This hyperpolarization together with the long nuclear-spin polarization lifetimes in nanodiamonds and the relatively high density of 13C nuclei has the potential to result in a major signal enhancement in 13C nuclear magnetic resonance imaging and suggests functionalized and hyperpolarized nanodiamonds as a unique probe for molecular imaging both in vitro and in vivo.

Next generation spin torque memories

CERN Document Server

Kaushik, Brajesh Kumar; Kulkarni, Anant Aravind; Prajapati, Sanjay

2017-01-01

This book offers detailed insights into spin transfer torque (STT) based devices, circuits and memories. Starting with the basic concepts and device physics, it then addresses advanced STT applications and discusses the outlook for this cutting-edge technology. It also describes the architectures, performance parameters, fabrication, and the prospects of STT based devices. Further, moving from the device to the system perspective it presents a non-volatile computing architecture composed of STT based magneto-resistive and all-spin logic devices and demonstrates that efficient STT based magneto-resistive and all-spin logic devices can turn the dream of instant on/off non-volatile computing into reality.

Single spin asymmetries and the spin of the proton

International Nuclear Information System (INIS)

Dominguez Z, G.; Herrera C, G.

2000-01-01

We study the spin asymmetries of inclusive π + , π 0 , π - , η and γ production in the interaction of a polarized with a non polarized proton, in the frame of a two component model. Particle production in the model is assumed to consist of a conventional QCD fragmentation process plus a recombination mechanism. The presence of Thomas precession in the recombination process seems to be responsible for the production spin asymmetry. (Author) 12 refs., 8 figs

Spin correlations of Λanti Λ pairs as a probe of quark-antiquark pair production

International Nuclear Information System (INIS)

Ellis, John; Hwang, Dae Sung

2012-01-01

The polarizations of Λ and anti Λ are thought to retain memories of the spins of their parent s quarks and anti s antiquarks, and are readily measurable via the angular distributions of their daughter protons and antiprotons. Correlations between the spins of Λ and anti Λ produced at low relative momenta may therefore be used to probe the spin states of s anti s pairs produced during hadronization. We consider the possibilities that they are produced in a 3 P 0 state, as might result from fluctuations in the magnitude of left angle anti ss right angle, a 1 S 0 state, as might result from chiral fluctuations, or a 3 S 1 or other spin state, as might result from production by a quark-antiquark or gluon pair. We provide templates for the p anti p angular correlations that would be expected in each of these cases, and discuss how they might be used to distinguish s anti s production mechanisms in pp and heavy-ion collisions. (orig.)

Spin correlations of {lambda}anti {lambda} pairs as a probe of quark-antiquark pair production

Energy Technology Data Exchange (ETDEWEB)

Ellis, John [King' s College London, Theoretical Particle Physics and Cosmology Group, Physics Department, London (United Kingdom); CERN, Theory Division, Physics Department, Geneva 23 (Switzerland); Hwang, Dae Sung [Sejong University, Department of Physics, Seoul (Korea, Republic of)

2012-02-15

The polarizations of {lambda} and anti {lambda} are thought to retain memories of the spins of their parent s quarks and anti s antiquarks, and are readily measurable via the angular distributions of their daughter protons and antiprotons. Correlations between the spins of {lambda} and anti {lambda} produced at low relative momenta may therefore be used to probe the spin states of s anti s pairs produced during hadronization. We consider the possibilities that they are produced in a {sup 3}P{sub 0} state, as might result from fluctuations in the magnitude of left angle anti ss right angle, a {sup 1}S{sub 0} state, as might result from chiral fluctuations, or a {sup 3}S{sub 1} or other spin state, as might result from production by a quark-antiquark or gluon pair. We provide templates for the p anti p angular correlations that would be expected in each of these cases, and discuss how they might be used to distinguish s anti s production mechanisms in pp and heavy-ion collisions. (orig.)

Large-scale bioenergy production: how to resolve sustainability trade-offs?

Science.gov (United States)

Humpenöder, Florian; Popp, Alexander; Bodirsky, Benjamin Leon; Weindl, Isabelle; Biewald, Anne; Lotze-Campen, Hermann; Dietrich, Jan Philipp; Klein, David; Kreidenweis, Ulrich; Müller, Christoph; Rolinski, Susanne; Stevanovic, Miodrag

2018-02-01

Large-scale 2nd generation bioenergy deployment is a key element of 1.5 °C and 2 °C transformation pathways. However, large-scale bioenergy production might have negative sustainability implications and thus may conflict with the Sustainable Development Goal (SDG) agenda. Here, we carry out a multi-criteria sustainability assessment of large-scale bioenergy crop production throughout the 21st century (300 EJ in 2100) using a global land-use model. Our analysis indicates that large-scale bioenergy production without complementary measures results in negative effects on the following sustainability indicators: deforestation, CO2 emissions from land-use change, nitrogen losses, unsustainable water withdrawals and food prices. One of our main findings is that single-sector environmental protection measures next to large-scale bioenergy production are prone to involve trade-offs among these sustainability indicators—at least in the absence of more efficient land or water resource use. For instance, if bioenergy production is accompanied by forest protection, deforestation and associated emissions (SDGs 13 and 15) decline substantially whereas food prices (SDG 2) increase. However, our study also shows that this trade-off strongly depends on the development of future food demand. In contrast to environmental protection measures, we find that agricultural intensification lowers some side-effects of bioenergy production substantially (SDGs 13 and 15) without generating new trade-offs—at least among the sustainability indicators considered here. Moreover, our results indicate that a combination of forest and water protection schemes, improved fertilization efficiency, and agricultural intensification would reduce the side-effects of bioenergy production most comprehensively. However, although our study includes more sustainability indicators than previous studies on bioenergy side-effects, our study represents only a small subset of all indicators relevant for the

Anisotropy and Suppression of Spin-Orbit Interaction in a GaAs Double Quantum Dot

Science.gov (United States)

Hofmann, A.; Maisi, V. F.; Krähenmann, T.; Reichl, C.; Wegscheider, W.; Ensslin, K.; Ihn, T.

2017-10-01

The spin-flip tunneling rates are measured in GaAs-based double quantum dots by time-resolved charge detection. Such processes occur in the Pauli spin blockade regime with two electrons occupying the double quantum dot. Ways are presented for tuning the spin-flip tunneling rate, which on the one hand gives access to measuring the Rashba and Dresselhaus spin-orbit coefficients. On the other hand, they make it possible to turn on and off the effect of spin-orbit interaction with a high on/off ratio. The tuning is accomplished by choosing the alignment of the tunneling direction with respect to the crystallographic axes, as well as by choosing the orientation of the external magnetic field with respect to the spin-orbit magnetic field. Spin lifetimes of 10 s are achieved at a tunneling rate close to 1 kHz.

Anisotropy and Suppression of Spin-Orbit Interaction in a GaAs Double Quantum Dot.

Science.gov (United States)

Hofmann, A; Maisi, V F; Krähenmann, T; Reichl, C; Wegscheider, W; Ensslin, K; Ihn, T

2017-10-27

The spin-flip tunneling rates are measured in GaAs-based double quantum dots by time-resolved charge detection. Such processes occur in the Pauli spin blockade regime with two electrons occupying the double quantum dot. Ways are presented for tuning the spin-flip tunneling rate, which on the one hand gives access to measuring the Rashba and Dresselhaus spin-orbit coefficients. On the other hand, they make it possible to turn on and off the effect of spin-orbit interaction with a high on/off ratio. The tuning is accomplished by choosing the alignment of the tunneling direction with respect to the crystallographic axes, as well as by choosing the orientation of the external magnetic field with respect to the spin-orbit magnetic field. Spin lifetimes of 10 s are achieved at a tunneling rate close to 1 kHz.

Increasing off-service resident productivity while on their emergency department rotation using shift cards.

Science.gov (United States)

Chakravarthy, Bharath; Posadas, Emerson; Ibrahim, Deena; McArthur, Kurt; Osborn, Megan; Hoonpongsimanont, Wirachin; Wong, Andrew; Lotfipour, Shahram

2015-04-01

Differences in productivity between off-service residents rotating in the emergency department (ED) and their emergency medicine (EM) resident counterparts have never been directly quantified. We sought to quantify the difference between off-service residents rotating in the ED and their EM resident counterparts. We also sought to find whether shift cards could be used to increase the productivity of off-service residents rotating in the ED. This is a prospective cohort study conducted at an urban, tertiary, Level I trauma center. We implemented the use of shift cards for off-service residents during their EM rotation. Completion of the shift card involved recording patients seen and their dispositions, procedures done, and documenting a learned bedside teaching point from their shift that day. Productivity was measured in terms of patients seen per hour (PPH) and relative value units per hour (RVU/h). Off-service residents showed a productivity of 0.529 PPH (95% confidence interval [CI] 0.493-0.566) and 1.40 RVU/h (95% CI 1.28-1.53) prior to implementation of shift cards. With the introduction of shift cards, productivity increased to 0.623 PPH (95% CI 0.584-0.663, p = 0.001) and 1.77 RVU/h (95% CI 1.64-1.91, p = 0.001). In comparison, first year EM resident productivity was 0.970 PPH (95% CI 0.918-1.02) and 3.01 RVU/h (95% CI 2.83-3.19). Shift cards can be used to foster motivation for off-service residents rotating in the ED, and is a simple and cost-effective method to improve system-based practices and utilization of resources. Copyright © 2015 Elsevier Inc. All rights reserved.

Inter-spin distance determination using L-band (1-2 GHz) non-adiabatic rapid sweep electron paramagnetic resonance (NARS EPR)

Science.gov (United States)

Kittell, Aaron W.; Hustedt, Eric J.; Hyde, James S.

2014-01-01

Site-directed spin-labeling electron paramagnetic resonance (SDSL EPR) provides insight into the local structure and motion of a spin probe strategically attached to a molecule. When a second spin is introduced to the system, macromolecular information can be obtained through measurement of inter-spin distances either by continuous wave (CW) or pulsed electron double resonance (ELDOR) techniques. If both methodologies are considered, inter-spin distances of 8 to 80 Å can be experimentally determined. However, there exists a region at the upper limit of the conventional X-band (9.5 GHz) CW technique and the lower limit of the four-pulse double electron-electron resonance (DEER) experiment where neither method is particularly reliable. The work presented here utilizes L-band (1.9 GHz) in combination with non-adiabatic rapid sweep (NARS) EPR to address this opportunity by increasing the upper limit of the CW technique. Because L-band linewidths are three to seven times narrower than those at X-band, dipolar broadenings that are small relative to the X-band inhomogeneous linewidth become observable, but the signal loss due to the frequency dependence of the Boltzmann factor, has made L-band especially challenging. NARS has been shown to increase sensitivity by a factor of five, and overcomes much of this loss, making L-band distance determination more feasible [1]. Two different systems are presented and distances of 18–30 Å have been experimentally determined at physiologically relevant temperatures. Measurements are in excellent agreement with a helical model and values determined by DEER. PMID:22750251

Confinement forces in fast backward nucleon production off nuclei

International Nuclear Information System (INIS)

Kopeliovich, B.Z.; Niedermayer, F.

1982-01-01

Multiple colour exchange mechanism is proposed to describe fast backward nucleon production off nuclei at high energies. Cross section of hd → psub(B)X reaction is calculated in the colour flux tube model. This contribution is found to dominate in the hard part of momentum spectra

How Rapid is Rapid Prototyping? Analysis of ESPADON Programme Results

Directory of Open Access Journals (Sweden)

Ian D. Alston

2003-05-01

Full Text Available New methodologies, engineering processes, and support environments are beginning to emerge for embedded signal processing systems. The main objectives are to enable defence industry to field state-of-the-art products in less time and with lower costs, including retrofits and upgrades, based predominately on commercial off the shelf (COTS components and the model-year concept. One of the cornerstones of the new methodologies is the concept of rapid prototyping. This is the ability to rapidly and seamlessly move from functional design to the architectural design to the implementation, through automatic code generation tools, onto real-time COTS test beds. In this paper, we try to quantify the term “rapid” and provide results, the metrics, from two independent benchmarks, a radar and sonar beamforming application subset. The metrics show that the rapid prototyping process may be sixteen times faster than a conventional process.

Rapid analytical extraction of volatile fermentation products

Energy Technology Data Exchange (ETDEWEB)

Jansen, N B; Flickinger, M C; Tsao, G T

1979-10-01

With renewed interest in production of liquid fuels and chemical feedstocks from carbohydrates, numerous authors have utilized gas-liquid chromatography (GC) for quantification of volatile products. Poor separation and short column life will result if residual sugars present in the medium are not separated from the volatile compounds before injection. In our current investigation of 2,3-butanediol production from xylose, we have developed a rapid GC assay for 2,3-butanediol, acetyl methyl carbinol (acetoin), 2,3-butanedione (diacetyl), and ethanol. This method extracts the fermentation products at high pH from residual xylose before injection into the GC. This routine is a modification of the method of Kolfenbach et al. and is more rapid than the method of separation of diacetyl and acetoin from carbohydrates by distillation reported by Gupta et al. Their erroneous reports of yields of 640 mg diacetyl + acetoin/g sugar are 30% higher than the theoretical maximum for Enterobacter cloacae (ATCC 27613) and points out the need for a reliable, accurate assay for these products.

Optimal matrix product states for the Heisenberg spin chain

International Nuclear Information System (INIS)

Latorre, Jose I; Pico, Vicent

2009-01-01

We present some exact results for the optimal matrix product state (MPS) approximation to the ground state of the infinite isotropic Heisenberg spin-1/2 chain. Our approach is based on the systematic use of Schmidt decompositions to reduce the problem of approximating for the ground state of a spin chain to an analytical minimization. This allows one to show that results of standard simulations, e.g. density matrix renormalization group and infinite time evolving block decimation, do correspond to the result obtained by this minimization strategy and, thus, both methods deliver optimal MPS with the same energy but, otherwise, different properties. We also find that translational and rotational symmetries cannot be maintained simultaneously by the MPS ansatz of minimum energy and present explicit constructions for each case. Furthermore, we analyze symmetry restoration and quantify it to uncover new scaling relations. The method we propose can be extended to any translational invariant Hamiltonian

A SEARCH FOR RAPIDLY SPINNING PULSARS AND FAST TRANSIENTS IN UNIDENTIFIED RADIO SOURCES WITH THE NRAO 43 METER TELESCOPE

Energy Technology Data Exchange (ETDEWEB)

Schmidt, Deborah; Crawford, Fronefield; Gilpin, Claire [Department of Physics and Astronomy, Franklin and Marshall College, P.O. Box 3003, Lancaster, PA 17604 (United States); Langston, Glen [National Radio Astronomy Observatory, P.O. Box 2, Green Bank, WV 24944 (United States)

2013-04-15

We have searched 75 unidentified radio sources selected from the NRAO VLA Sky Survey catalog for the presence of rapidly spinning pulsars and short, dispersed radio bursts. The sources are radio bright, have no identifications or optical source coincidences, are more than 5% linearly polarized, and are spatially unresolved in the catalog. If these sources are fast-spinning pulsars (e.g., sub-millisecond pulsars), previous large-scale pulsar surveys may have missed detection due to instrumental and computational limitations, eclipsing effects, or diffractive scintillation. The discovery of a sub-millisecond pulsar would significantly constrain the neutron star equation of state and would have implications for models predicting a rapid slowdown of highly recycled X-ray pulsars to millisecond periods from, e.g., accretion disk decoupling. These same sources were previously searched unsuccessfully for pulsations at 610 MHz with the Lovell Telescope at Jodrell Bank. This new search was conducted at a different epoch with a new 800 MHz backend on the NRAO 43 m Telescope at a center frequency of 1200 MHz. Our search was sensitive to sub-millisecond pulsars in highly accelerated binary systems and to short transient pulses. No periodic or transient signals were detected from any of the target sources. We conclude that diffractive scintillation, dispersive smearing, and binary acceleration are unlikely to have prevented detection of the large majority of the sources if they are pulsars, though we cannot rule out eclipsing, nulling or intermittent emission, or radio interference as possible factors for some non-detections. Other (speculative) possibilities for what these sources might include radio-emitting magnetic cataclysmic variables or older pulsars with aligned magnetic and spin axes.

Possible evidence for spin-transfer torque induced by spin-triplet supercurrent

KAUST Repository

Li, Lailai

2017-10-04

Cooper pairs in superconductors are normally spin singlet. Nevertheless, recent studies suggest that spin-triplet Cooper pairs can be created at carefully engineered superconductor-ferromagnet interfaces. If Cooper pairs are spin-polarized they would transport not only charge but also a net spin component, but without dissipation, and therefore minimize the heating effects associated with spintronic devices. Although it is now established that triplet supercurrents exist, their most interesting property - spin - is only inferred indirectly from transport measurements. In conventional spintronics, it is well known that spin currents generate spin-transfer torques that alter magnetization dynamics and switch magnetic moments. The observation of similar effects due to spin-triplet supercurrents would not only confirm the net spin of triplet pairs but also pave the way for applications of superconducting spintronics. Here, we present a possible evidence for spin-transfer torques induced by triplet supercurrents in superconductor/ferromagnet/superconductor (S/F/S) Josephson junctions. Below the superconducting transition temperature T_c, the ferromagnetic resonance (FMR) field at X-band (~ 9.0 GHz) shifts rapidly to a lower field with decreasing temperature due to the spin-transfer torques induced by triplet supercurrents. In contrast, this phenomenon is absent in ferromagnet/superconductor (F/S) bilayers and superconductor/insulator/ferromagnet/superconductor (S/I/F/S) multilayers where no supercurrents pass through the ferromagnetic layer. These experimental observations are discussed with theoretical predictions for ferromagnetic Josephson junctions with precessing magnetization.

Material Implications of Rural Electrification—A Methodological Framework to Assess In-Use Stocks of Off-Grid Solar Products and EEE in Rural Households in Bangladesh

Directory of Open Access Journals (Sweden)

Alexander Batteiger

2018-02-01

Full Text Available “Universal access to electricity” is proclaimed as the seventh sustainable development goal (SDG 7 of the United Nations (UN Sustainable Development Goals list. The achievement of this goal will result in a rapid diffusion of energy technologies that would in turn increase materials stocks, subsequently increase the raw material demand as well as the arising waste flows. This study describes a methodological framework to assess in-use stocks of off-grid solar products and electrical and electronic equipment (EEE for rural communities in developing countries. The methodology is based on energy-access data. Furthermore, the specifics of the characteristics of off-grid solar products are discussed. The methodology is applied to rural Bangladesh and its solar home system (SHS program. By the end of 2016, around 4.1 million SHSs were installed. This type of access to electricity has a significant impact on the in-use stocks, as households add the comparatively heavy SHSs to their in-use stocks. In-use stocks of EEE, in general, are low. Off-grid solar products are lighter than standard EEE, and fewer products types are available. These findings will help to better understand material stocks and future waste flows in the given context and will support the adaption of recycling infrastructures.

Competition between Bose-Einstein Condensation and Spin Dynamics.

Science.gov (United States)

Naylor, B; Brewczyk, M; Gajda, M; Gorceix, O; Maréchal, E; Vernac, L; Laburthe-Tolra, B

2016-10-28

We study the impact of spin-exchange collisions on the dynamics of Bose-Einstein condensation by rapidly cooling a chromium multicomponent Bose gas. Despite relatively strong spin-dependent interactions, the critical temperature for Bose-Einstein condensation is reached before the spin degrees of freedom fully thermalize. The increase in density due to Bose-Einstein condensation then triggers spin dynamics, hampering the formation of condensates in spin-excited states. Small metastable spinor condensates are, nevertheless, produced, and they manifest in strong spin fluctuations.

Boson-mediated quantum spin simulators in transverse fields: X Y model and spin-boson entanglement

Science.gov (United States)

Wall, Michael L.; Safavi-Naini, Arghavan; Rey, Ana Maria

2017-01-01

The coupling of spins to long-wavelength bosonic modes is a prominent means to engineer long-range spin-spin interactions, and has been realized in a variety of platforms, such as atoms in optical cavities and trapped ions. To date, much of the experimental focus has been on the realization of long-range Ising models, but generalizations to other spin models are highly desirable. In this work, we explore a previously unappreciated connection between the realization of an X Y model by off-resonant driving of a single sideband of boson excitation (i.e., a single-beam Mølmer-Sørensen scheme) and a boson-mediated Ising simulator in the presence of a transverse field. In particular, we show that these two schemes have the same effective Hamiltonian in suitably defined rotating frames, and analyze the emergent effective X Y spin model through a truncated Magnus series and numerical simulations. In addition to X Y spin-spin interactions that can be nonperturbatively renormalized from the naive Ising spin-spin coupling constants, we find an effective transverse field that is dependent on the thermal energy of the bosons, as well as other spin-boson couplings that cause spin-boson entanglement not to vanish at any time. In the case of a boson-mediated Ising simulator with transverse field, we discuss the crossover from transverse field Ising-like to X Y -like spin behavior as a function of field strength.

Measurement of Spin Observables in Inclusive Lambda and Neutral Kaon (short) Production with a 200 GEV Polarized Proton Beam.

Science.gov (United States)

Bravar, Alessandro

The considerable polarization of hyperons produced at high x_ F has been known for a long time and has been interpreted in various theoretical models in terms of the constituents' spin. The spin dependence in inclusive Lambda and K _sp{s}{circ} production has been studied for the first time at high energy using the Fermilab 200 GeV/c polarized proton beam and a large forward spectrometer. The spin observables analyzing power A_ N, polarization P_0 and depolarization D _{NN} in inclusive Lambda production has been measured in the kinematic range of rm 0.2current picture of spin effects in hadronic interactions is much more complex than naively thought. The data on the spin dependence of the Lambda inclusive production indicate a substantial negative asymmetry A_ N at large x _ F and moderate p_ T, the polarization results P_0 are in fair agreement with previous measurements, and the double spin parameter D_ {NN} increases with x_ F and p_ T to relatively large positive values. The trend of the Lambda A_ N, which shows a kinematical behavior similar to P_0 with same sign but smaller in magnitude, might be suggestive of a common interpretation. These results, however, are difficult to accommodate within the present quark fragmentation models for hyperon polarization, based on SU(6) wave functions where the produced strange quark carries all the spin information of the Lambda, unless spectator di-quarks in the recombination process play a more significant role than generally expected. These results can further test the current ideas on the underlying mechanisms for the hyperon polarization and meson production asymmetry.

Donor-driven spin relaxation in multivalley semiconductors.

Science.gov (United States)

Song, Yang; Chalaev, Oleg; Dery, Hanan

2014-10-17

The observed dependence of spin relaxation on the identity of the donor atom in n-type silicon has remained without explanation for decades and poses a long-standing open question with important consequences for modern spintronics. Taking into account the multivalley nature of the conduction band in silicon and germanium, we show that the spin-flip amplitude is dominated by short-range scattering off the central-cell potential of impurities after which the electron is transferred to a valley on a different axis in k space. Through symmetry arguments, we show that this spin-flip process can strongly affect the spin relaxation in all multivalley materials in which time-reversal cannot connect distinct valleys. From the physical insights gained from the theory, we provide guidelines to significantly enhance the spin lifetime in semiconductor spintronics devices.

Simultaneous production of spin-polarized ions/electrons based on two-photon ionization of laser-ablated metallic atoms

International Nuclear Information System (INIS)

Nakajima, Takashi; Yonekura, Nobuaki; Matsuo, Yukari; Kobayashi, Tohru; Fukuyama, Yoshimitsu

2003-01-01

We demonstrate the simultaneous production of spin-polarized ions/electrons using two-color, two-photon ionization of laser-ablated metallic atoms. Specifically, we have applied the developed technique to laser-ablated Sr atoms, and found that the electron-spin polarization of Sr + ions, and accordingly, the spin polarization of photoelectrons is 64%±9%, which is in good agreement with the theoretical prediction we have recently reported [T. Nakajima and N. Yonekura, J. Chem. Phys. 117, 2112 (2002)]. Our experimental results open up a simple way toward the construction of a spin-polarized dual ion/electron source

Product Quality Assurance for Off-Grid Lighting in Africa

Energy Technology Data Exchange (ETDEWEB)

World Bank; Mills, Evan; Mills, Evan

2008-07-13

Although the emergence of markets for high efficiency off-grid lighting technologies holds promise, realizing the potential of this opportunity on a long-term, sustainable basis requires careful attention to issues of product quality, consumer protection, and the potential for significant 'market spoiling', in anticipation of increases of sales of low cost, low performance off-grid lighting products. The goal of the Lighting Africa quality assurance workshop was to articulate strategies to mitigate the dangers of market spoiling and to explore ways to protect consumers from misleading advertising for sales of inferior, off-grid lighting products in the context of Lighting Africa's overarching objective to support the industry in developing a robust off-grid lighting market in Africa. The workshop resulted in the identification of two strategic approaches for meeting Lighting Africa quality assurance programmatic needs. The first strategy is intended to meet a short-term programmatic need for quality associated with requests for lighting products by bulk procurement agents, such as in a World Bank-financed project. The development of procurement specifications and test procedures that could be used in a quality/usability screening method in order to provide guidance for forthcoming large volume purchases emerged as the best solution to meet this need. Such approaches are used in World Bank-financed solar home systems (SHSs) projects in Bangladesh, Sri Lanka, and China, among others. However, unlike the SHSs which have multiple balance-of-system (BOS) components warranting the need for an array of specifications for individual components, stand alone lighting systems require specifications that are amenable to individual light points. To test this approach, Lighting Africa elected to use the technical specifications issued by the Photovoltaic Global Approval Program for solar lanterns that use CFL bulbs (PVRS11A) as the basis of qualifying such

Chargino production and decay in photon-photon collisions

International Nuclear Information System (INIS)

Mayer, T.; Bloechinger, C.; Franke, F.; Fraas, H.

2003-01-01

We discuss the pair production of charginos in collisions of polarized photons, γγ→χ i + χ i - (i=1,2), and the subsequent leptonic decay of the lighter chargino χ 1 + →χ 1 0 e + ν e including the complete spin correlations. Analytical formulae are given for the polarization and the spin-spin correlations of the charginos. Since the production is a pure QED process the decay dynamics can be studied separately. For high energy photons from Compton backscattering of polarized laser pulses off polarized electron beams numerical results are presented for the cross section, the angular distribution and the forward-backward asymmetry of the decay positron. Finally we study the dependence on the gaugino mass parameter M 1 and on the sneutrino mass for a gaugino-like MSSM scenario. (orig.)

XXZ scalar products and KP

International Nuclear Information System (INIS)

Foda, O.; Wheeler, M.; Zuparic, M.

2009-01-01

Using a Jacobi-Trudi-type identity, we show that the scalar product of a general state and a Bethe eigenstate in a finite-length XXZ spin-1/2 chain is (a restriction of) a KP τ function. This leads to a correspondence between the eigenstates and points on Sato's Grassmannian. Each of these points is a function of the rapidities of the corresponding eigenstate, the inhomogeneity variables of the spin chain and the crossing parameter.

Global positioning of spin GPS scheme for half-spin massive spinors

CERN Document Server

Jadach, Stanislaw; Was, Zbigniew

2001-01-01

We present a simple and flexible method of keeping track of the complex phases and spin quantisation axes for half-spin initial- and final-state Weyl spinors in scattering amplitudes of Standard Model high energy physics processes. Both cases of massless and massive spinors are discussed. The method is demonstrated and checked numerically for spin correlations in tau tau production and decay. Its application is in our work of combining effects due to multiple photon emission (exponentiation) and spin, embodied in the Monte Carlo event generators for production and decay of unstable fermions such as the, tau lepton, t-quark and hypothetical new heavy particles. In particular, the recurrent problem of combining, for such unstable fermions, one author's calculation of production and another author's calculation of decay, in the presence or absence of multiple photon effects, is there given a practical solution, both for Weyl spinor methods and for the traditional Jacob-Wick helicity methods. Moreover, for massiv...

Spin Hall effects

Science.gov (United States)

Sinova, Jairo; Valenzuela, Sergio O.; Wunderlich, J.; Back, C. H.; Jungwirth, T.

2015-10-01

Spin Hall effects are a collection of relativistic spin-orbit coupling phenomena in which electrical currents can generate transverse spin currents and vice versa. Despite being observed only a decade ago, these effects are already ubiquitous within spintronics, as standard spin-current generators and detectors. Here the theoretical and experimental results that have established this subfield of spintronics are reviewed. The focus is on the results that have converged to give us the current understanding of the phenomena, which has evolved from a qualitative to a more quantitative measurement of spin currents and their associated spin accumulation. Within the experimental framework, optical-, transport-, and magnetization-dynamics-based measurements are reviewed and linked to both phenomenological and microscopic theories of the effect. Within the theoretical framework, the basic mechanisms in both the extrinsic and intrinsic regimes are reviewed, which are linked to the mechanisms present in their closely related phenomenon in ferromagnets, the anomalous Hall effect. Also reviewed is the connection to the phenomenological treatment based on spin-diffusion equations applicable to certain regimes, as well as the spin-pumping theory of spin generation used in many measurements of the spin Hall angle. A further connection to the spin-current-generating spin Hall effect to the inverse spin galvanic effect is given, in which an electrical current induces a nonequilibrium spin polarization. This effect often accompanies the spin Hall effect since they share common microscopic origins. Both can exhibit the same symmetries when present in structures comprising ferromagnetic and nonmagnetic layers through their induced current-driven spin torques or induced voltages. Although a short chronological overview of the evolution of the spin Hall effect field and the resolution of some early controversies is given, the main body of this review is structured from a pedagogical

Spin polarization in top pair production in association with two photons at NLO+PS

CERN Document Server

Luisoni, Gionata

2018-01-01

This talk focuses on the impact of top-quark spin polarization effects in Higgs boson production in association with a top-quark pair, where the Higgs boson decays to two photons. Predictions for the signal are compared with direct top-quark pair production in association with two photons at NLO+PS.

Spin polarization in top pair production in association with two photons at NLO+PS

CERN Document Server

Luisoni, Gionata

2017-01-01

This talk focuses on the impact of top-quark spin polarization effects in Higgs boson production in association with a top-quark pair, where the Higgs boson decays to two photons. Predictions for the signal are compared with direct top-quark pair production in association with two photons at NLO+PS.

INTRINSIC ELECTROMAGNETIC VARIABILITY IN CELESTIAL OBJECTS CONTAINING RAPIDLY SPINNING BLACK HOLES

Energy Technology Data Exchange (ETDEWEB)

Zhang, Fan, E-mail: fnzhang@bnu.edu.cn [Gravitational Wave and Cosmology Laboratory, Department of Astronomy, Beijing Normal University, Beijing 100875 (China); Department of Physics and Astronomy, West Virginia University, P.O. Box 6315, Morgantown, WV 26506 (United States)

2016-02-10

Analytical studies have raised the concern that a mysterious expulsion of magnetic field lines by a rapidly spinning black hole (dubbed the black hole Meissner effect) would shut down the Blandford–Znajek process and quench the jets of active galactic nuclei and microquasars. This effect is, however, not seen observationally or in numerical simulations. Previous attempts at reconciling the predictions with observations have proposed several mechanisms to evade the Meissner effect. In this paper, we identify a new evasion mechanism and discuss its observational significance. Specifically, we show that the breakdown of stationarity is sufficient to remove the expulsion of the magnetic field at all multipole orders, and that the associated temporal variation is likely turbulent because of the existence of efficient mechanisms for sharing energy across different modes. Such an intrinsic (as opposed to being driven externally by, e.g., changes in the accretion rate) variability of the electromagnetic field can produce the recorded linear correlation between microvariability amplitudes and mean fluxes, help create magnetic randomness and seed sheared magnetic loops in jets, and lead to a better theoretical fit to the X-ray microvariability power spectral density.

Experimental analysis of the production of micro- and nanofibres by Laser Spinning

International Nuclear Information System (INIS)

Quintero, F.; Pou, J.; Lusquinos, F.; Riveiro, A.

2007-01-01

Laser Spinning is a new technique for the production of glass fibres with diameters in the nanometre to micrometre scale. It allows large quantities of nanofibres to be made with specific, controllable chemical compositions. Furthermore, the production of amorphous micro- and nanofibres of non-ready glass former materials was demonstrated. All these novel characteristics will potentially open up a whole new range of applications for the fibres. In this technique a high power laser is employed to melt the precursor solid material, while a supersonic gas jet is injected into the melt volume. The melt forms glass fibres as a result of its viscous elongation and cooling by the drag force and convective heat transfer produced by the gas jet. The influence of several operating conditions controlling the morphology, composition, and diameter distribution of the fibres is experimentally assessed by means of electron microscopy analysis, X-ray fluorescence and time-of-flight secondary ion mass spectrometry. The experimental results are discussed based on a theoretical explanation of the process of fibre formation. This leads ultimately to the deduction of a set of rules regarding the influence of the factors studied on the production of nanofibres by Laser Spinning

Methylisothiazolinone in rinse-off products causes allergic contact dermatitis

DEFF Research Database (Denmark)

Yazar, K; Lundov, Michael Dyrgaard; Faurschou, A

2015-01-01

the potential to cause allergic contact dermatitis. METHODS: Nineteen MI-allergic subjects and 19 controls without MI allergy applied two liquid hand soaps five times per day on areas of 5 × 10 cm(2) on the ventral side of their forearms. One soap contained 100 ppm MI, the maximum allowed concentration......BACKGROUND: In recent years, the prevalence of contact allergy to the preservative methylisothiazolinone (MI) has increased dramatically. Cosmetic products are one of the major sources of exposure. OBJECTIVES: To examine whether allowed concentrations of MI in cosmetic rinse-off products have...

Soft gluon resummation for the single-spin production of W±-bosons

International Nuclear Information System (INIS)

Weber, A.

1993-01-01

We carefully study the production of W ± -bosons in singly-polarized hadron-hadron collisions. In the region of small transverse momenta of the produced W ± we perform the soft gluon resummation to double logarithmic accuracy. Special emphasis is laid on matching the resummed expression to the O(α s ) perturbative result valid at large transverse momenta. We investigate the phenomenological relevance of our results for pp-collisions at RHIC and show that in the future single-spin W ± -production may help to shed more light on the surprising EMC-result. (orig.)

Measuring absolute spin polarization in dissolution-DNP by Spin PolarimetrY Magnetic Resonance (SPY-MR).

OpenAIRE

Vuichoud , Basile; Milani , Jonas; Chappuis , Quentin; Bornet , Aurélien; Bodenhausen , Geoffrey; Jannin , Sami

2015-01-01

Dynamic nuclear polarization at 1.2 K and 6.7 T allows one to achieve spin temperatures on the order of a few millikelvin, so that the high-temperature approximation (Delta E < kT) is violated for the nuclear Zeeman interaction Delta E = gamma B(0)h/(2 pi) of most isotopes. Provided that, after rapid dissolution and transfer to an NMR or MRI system, the hyperpolarized molecules contain at least two nuclear spins I and S with a scalar coupling J(IS), the polarization of spin I (short for 'inve...

XXZ scalar products and KP

Energy Technology Data Exchange (ETDEWEB)

Foda, O. [Department of Mathematics and Statistics, University of Melbourne, Parkville, Victoria 3010 (Australia)], E-mail: foda@ms.unimelb.edu.au; Wheeler, M. [Department of Mathematics and Statistics, University of Melbourne, Parkville, Victoria 3010 (Australia)], E-mail: mwheeler@ms.unimelb.edu.au; Zuparic, M. [Department of Mathematics and Statistics, University of Melbourne, Parkville, Victoria 3010 (Australia)], E-mail: mzup@ms.unimelb.edu.au

2009-10-21

Using a Jacobi-Trudi-type identity, we show that the scalar product of a general state and a Bethe eigenstate in a finite-length XXZ spin-1/2 chain is (a restriction of) a KP {tau} function. This leads to a correspondence between the eigenstates and points on Sato's Grassmannian. Each of these points is a function of the rapidities of the corresponding eigenstate, the inhomogeneity variables of the spin chain and the crossing parameter.

Age-related differences in lower-limb force-time relation during the push-off in rapid voluntary stepping.

Science.gov (United States)

Melzer, I; Krasovsky, T; Oddsson, L I E; Liebermann, D G

2010-12-01

This study investigated the force-time relationship during the push-off stage of a rapid voluntary step in young and older healthy adults, to study the assumption that when balance is lost a quick step may preserve stability. The ability to achieve peak propulsive force within a short time is critical for the performance of such a quick powerful step. We hypothesized that older adults would achieve peak force and power in significantly longer times compared to young people, particularly during the push-off preparatory phase. Fifteen young and 15 older volunteers performed rapid forward steps while standing on a force platform. Absolute anteroposterior and body weight normalized vertical forces during the push-off in the preparation and swing phases were used to determine time to peak and peak force, and step power. Two-way analyses of variance ('Group' [young-older] by 'Phase' [preparation-swing]) were used to assess our hypothesis (P ≤ 0.05). Older people exerted lower peak forces (anteroposterior and vertical) than young adults, but not necessarily lower peak power. More significantly, they showed a longer time to peak force, particularly in the vertical direction during the preparation phase. Older adults generate propulsive forces slowly and reach lower magnitudes, mainly during step preparation. The time to achieve a peak force and power, rather than its actual magnitude, may account for failures in quickly performing a preventive action. Such delay may be associated with the inability to react and recruit muscles quickly. Thus, training elderly to step fast in response to relevant cues may be beneficial in the prevention of falls. Copyright © 2010 Elsevier Ltd. All rights reserved.

ISOTROPIC HEATING OF GALAXY CLUSTER CORES VIA RAPIDLY REORIENTING ACTIVE GALACTIC NUCLEUS JETS

International Nuclear Information System (INIS)

Babul, Arif; Sharma, Prateek; Reynolds, Christopher S.

2013-01-01

Active galactic nucleus (AGN) jets carry more than sufficient energy to stave off catastrophic cooling of the intracluster medium (ICM) in the cores of cool-core clusters. However, in order to prevent catastrophic cooling, the ICM must be heated in a near-isotropic fashion and narrow bipolar jets with P jet = 10 44–45 erg s –1 , typical of radio AGNs at cluster centers, are inefficient in heating the gas in the transverse direction to the jets. We argue that due to existent conditions in cluster cores, the supermassive black holes (SMBHs) will, in addition to accreting gas via radiatively inefficient flows, experience short stochastic episodes of enhanced accretion via thin disks. In general, the orientation of these accretion disks will be misaligned with the spin axis of the black holes (BHs) and the ensuing torques will cause the BH's spin axis (and therefore the jet axis) to slew and rapidly change direction. This model not only explains recent observations showing successive generations of jet-lobes-bubbles in individual cool-core clusters that are offset from each other in the angular direction with respect to the cluster center, but also shows that AGN jets can heat the cluster core nearly isotropically on the gas cooling timescale. Our model does require that the SMBHs at the centers of cool-core clusters be spinning relatively slowly. Torques from individual misaligned disks are ineffective at tilting rapidly spinning BHs by more than a few degrees. Additionally, since SMBHs that host thin accretion disks will manifest as quasars, we predict that roughly 1-2 rich clusters within z < 0.5 should have quasars at their centers.

The spin predictions of the relativistic quark model for baryon decuplet production

CERN Document Server

Montvay, István

1973-01-01

Single-quark scattering contributions are considered in the case of ground-state decuplet baryon production. It is shown within the framework of an explicitly covariant approach that the spin consequences of the quark additivity assumption hold in the t-channel helicity frame independently of much of the details of the model. (12 refs).

Spin Transfer in Inclusive Λ0 Production by Transversely Polarized Protons at 200GeV/c

International Nuclear Information System (INIS)

Grosnick, D.P.; Hill, D.A.; Laghai, M.; Lopiano, D.; Ohashi, Y.; Spinka, H.; Stanek, R.W.; Underwood, D.G.; Yokosawa, A.; Bystricky, J.; Lehar, F.; Lesquen, A. de; Rossum, L. van; Cossairt, J.D.; Read, A.L.; Iwatani, K.; Belikov, N.I.; Derevschikov, A.A.; Grachov, O.A.; Matulenko, Y.A.; Meschanin, A.P.; Nurushev, S.B.; Patalakha, D.I.; Rykov, V.L.; Solovyanov, V.L.; Vasiliev, A.N.; Akchurin, N.; Onel, Y.; Maki, T.; Enyo, H.; Funahashi, H.; Goto, Y.; Iijima, T.; Imai, K.; Itow, Y.; Makino, S.; Masaike, A.; Miyake, K.; Nagamine, T.; Saito, N.; Yamashita, S.; Takashima, R.; Takeutchi, F.; Kuroda, K.; Michalowicz, A.; Rappazzo, G.F.; Salvato, G.; Luehring, F.C.; Miller, D.H.; Tamura, N.; Yoshida, T.; Adams, D.L.; Bonner, B.E.; Corcoran, M.D.; Cranshaw, J.; Nessi-Tedaldi, F.; Nessi, M.; Nguyen, C.; Roberts, J.B.; Skeens, J.; White, J.L.; Bravar, A.

1997-01-01

Surprisingly large polarizations in hyperon production by unpolarized protons have been known for a long time. The spin dynamics of the production process can be further investigated with polarized beams. Recently, a negative asymmetry A N was found in inclusive Λ 0 production with a 200GeV/c transversely polarized proton beam. The depolarization D NN in p↑+p→Λ 0 +X has been measured with the same beam over a wide x F range and at moderate p T . D NN reaches positive values of about 30% at high x F and p T ∼1.0GeV/c . This result shows a sizable spin transfer from the incident polarized proton to the outgoing Λ 0 . copyright 1997 The American Physical Society

Off-axis spin orientation in goethite nanoparticles

DEFF Research Database (Denmark)

Brok, Erik; Lefmann, Kim; Nilsen, Gøran Jan

2017-01-01

structure of goethite has been challenging, and few detailed studies have been published. Even today, not all aspects of the magnetic structure are well established. Here, we investigate the magnetic structure of three samples of goethite nanoparticles with polarized neutron powder diffraction (xyz-polarization......Neutron diffraction is a powerful technique for determining the magnetic structure of antiferromagnetic materials. However, for some of these, determining the detailed magnetic structure remains a challenge. In goethite (α-FeOOH) the antiferromagnetic unit cell coincides with the chemical unit cell...... are mostly single crystalline. The polarization analysis enables us to separate magnetic scattering from nuclear and spin-incoherent scattering, resulting in data that can readily be analyzed. For the two samples with the larger particle size, we find nuclear correlation lengths in the [100] direction...

Quantum computers based on electron spins controlled by ultrafast off-resonant single optical pulses.

Science.gov (United States)

Clark, Susan M; Fu, Kai-Mei C; Ladd, Thaddeus D; Yamamoto, Yoshihisa

2007-07-27

We describe a fast quantum computer based on optically controlled electron spins in charged quantum dots that are coupled to microcavities. This scheme uses broadband optical pulses to rotate electron spins and provide the clock signal to the system. Nonlocal two-qubit gates are performed by phase shifts induced by electron spins on laser pulses propagating along a shared waveguide. Numerical simulations of this scheme demonstrate high-fidelity single-qubit and two-qubit gates with operation times comparable to the inverse Zeeman frequency.

Topological Material-Based Spin Devices

Science.gov (United States)

Zhang, Minhao; Wang, Xuefeng

Three-dimensional topological insulators have insulating bulk and gapless helical surface states. One of the most fascinating properties of the metallic surface states is the spin-momentum helical locking. The giant current-driven torques on the magnetic layer have been discovered in TI/ferromagnet bilayers originating from the spin-momentum helical locking, enabling the efficient magnetization switching with a low current density. We demonstrated the current-direction dependent on-off state in TIs-based spin valve devices for memory and logic applications. Further, we demonstrated the Bi2Se3 system will go from a topologically nontrivial state to a topologically trivial state when Bi atoms are replaced by lighter In atoms. Here, topologically trivial metal (BixIny)2 Se3 with high mobility also facilitates the realization of its application in multifunctional spintronic devices.

Spin Dependent Electronic Structure of Doped Manganese Perovskites

International Nuclear Information System (INIS)

Park, J.-H.

1999-01-01

The spin-resolved photoemission spectra were successfully obtained from La0.7Sr0.3MnO3 190 nm thick epitaxial film on SrTiO3(001). Well below Tc the results clearly manifest the half-metallic nature, i.e., for the majority spin, the photoemission spectrum clearly shows a metallic Fermi cut-off, whereas for the minority spin, it shows an insulating gap with disappearance of the spectral weight at ∼0.6 eV binding energy. On heating through Tc the spectra show no difference for different spins and the spectra weight at the Fermi level (EF disappears, indicating that the Mn 3d spins become disordered) and the system undergoes the ferromagnetic metal to paramagnetic non-metal transition. (c) 2000 American Vacuum Society

Selective Trapping of Volatile Fission Products with an Off-Gas Treatment System

Energy Technology Data Exchange (ETDEWEB)

B.R. Westphal; J.J. Park; J.M. Shin; G.I. Park; K.J. Bateman; D.L. Wahlquist

2008-07-01

A head-end processing step, termed DEOX for its emphasis on decladding via oxidation, is being developed for the treatment of spent oxide fuel by pyroprocessing techniques. The head-end step employs high temperatures to oxidize UO2 to U3O8 resulting in the separation of fuel from cladding and the removal of volatile fission products. Development of the head-end step is being performed in collaboration with the Korean Atomic Energy Research Institute (KAERI) through an International Nuclear Energy Research Initiative. Following the initial experimentation for the removal of volatile fission products, an off-gas treatment system was designed in conjunction with KAERI to collect specific fission gases. The primary volatile species targeted for trapping were iodine, technetium, and cesium. Each species is intended to be collected in distinct zones of the off-gas system and within those zones, on individual filters. Separation of the volatile off-gases is achieved thermally as well as chemically given the composition of the filter media. A description of the filter media and a basis for its selection will be given along with the collection mechanisms and design considerations. In addition, results from testing with the off-gas treatment system will be presented.

Transverse single spin asymmetry in Drell-Yan production in polarized pA collisions

NARCIS (Netherlands)

Zhou, J.

2015-01-01

We study the transverse single spin asymmetry in Drell-Yan production in pA collisions with incoming protons being transversely polarized. We carry out the calculation using a newly developed hybrid approach. The polarized cross section computed in the hybrid approach is consistent with that

Double Spin Asymmetries, ALL, for Di-hadrons in PHENIX

Science.gov (United States)

McKinney, Cameron

2010-11-01

The Relativistic Heavy Ion Collider (RHIC), through its polarized proton-proton collisions, provides leading order access to δG, the gluon contribution to the proton spin. Previous measurements have shown δG(x) dx to be consistent with zero in the Bjorken-x range of 0.05 to 0.2, whereas there is presently no measurement constraining δG (x) for x below or above this range. The Muon Piston Calorimeter provides the opportunity to expand the constrained range by allowing measurements of double spin asymmetries for azimuthally-separated pairs of 0̂'s at forward rapidity, 3.1<=|η|<=3.9, for √s=200 GeV and 500 GeV data taken in 2009. We present PYTHIA simulations studying the kinematics and possible asymmetries from di-hadron production at RHIC.

Spin-dependent Nucleon Structure Studies at MIT/Bates

International Nuclear Information System (INIS)

Botto, T.

2005-01-01

We present preliminary results from recent measurements of the proton, neutron and deuterium electro-magnetic form factors obtained by the BLAST collaboration at the MIT/Bates Linear Accelerator Facility. BLAST (Bates Large Acceptance Spectrometer Toroid) is a large-acceptance multi-purpose detector dedicated to studies of exclusive spin-dependent electron scattering from internal polarized targets. BLAST makes use of stored electron beam currents in excess of 150 mA with a 60-70% polarization. The electron beam is let through a 15 mm diameter, 60 cm long open-ended storage cell which is fed with ultra-pure, high-polarization H1,D1 gas from an Atomic Beam Source. The target polarization can be rapidly reversed between different vector and tensor target states, thus minimizing systematic uncertainties. The target spin can be oriented to any in-plane direction via a set of Helmholtz coils. Target polarizations in the storage cell of up to 80% (vector) and 70% (tensor) have been routinely achieved over a period of several months. Our data on the D-vector(e-vector,e'n) reaction off vector polarized deuterium allow for a unique extraction of the neutron charge form factor G E n . At same time, complementary measurements of G M n , T20 and the spin-dependent nucleon momentum distributions in deuterium are obtained via the D-vector(e-vector,e'), D (e-vector,e'd) and D (e-vector,e'p) reactions. In addition, BLAST data on vector polarized hydrogen will provide novel measurements of the GE/GM form-factor ratio on the proton as well as of the spin-dependent electro-excitation of the Δ(1232) resonance. Such comprehensive program on few body physics is now well underway and preliminary data will be presented

Instantons and magnetization tunneling: Beyond the giant-spin approximation

International Nuclear Information System (INIS)

Florez, J.M.; Vargas, P.; Nunez, Alvaro S.

2009-01-01

In this work we show that commonly neglected fluctuations of the net total spin of a molecular nanomagnet strongly modified its tunneling properties and provide a scenario to explain some discrepancies between theory and experiment. Starting off from an effective spin Hamiltonian, we study the quantum tunneling of the magnetization of molecular nanomagnets in the regime where the giant-spin approximation is breaking down. This study is done using an instanton description of the tunneling path. The instanton is calculated considering its coupling to quantum fluctuations.

An EPR spin-probe and spin-trap study of the free radicals produced by plant plasma membranes

Directory of Open Access Journals (Sweden)

GORAN BACIC

2005-02-01

Full Text Available Plant plasma membranes are known to produce superoxide radicals, while the production of hydroxyl radical is thought to occur only in the cell wall. In this work it was demonstrated using combined spin-trap and spin-probe EPR spectroscopic techniques, that plant plasma membranes do produce superoxide and hydroxyl radicals but by kinetically different mechanisms. The results show that superoxide and hydroxyl radicals can be detected by DMPO spin-trap and that the mechanisms and location of their production can be differentiated using the reduction of spin-probes Tempone and 7-DS. It was shown that the mechanism of production of oxygen reactive species is NADH dependent and diphenylene iodonium inhibited. The kinetics of the reduction of Tempone, combined with scavengers or the absence of NADH indicates that hydroxyl radicals are produced by a mechanism independent of that of superoxide production. It was shown that a combination of the spin-probe and spin-trap technique can be used in free radical studies of biological systems, with a number of advantages inherent to them.

Phytoplankton pigments and primary production around the oil fields off Maharashtra

Digital Repository Service at National Institute of Oceanography (India)

JiyalalRam, M.J.; Ramaiah, Neelam; Mehta, P.; Krishnakumari, L.; Nair, V.R.

Studies on phytoplankton pigments, primary productivity and particulate organic carbon were made at 21 locations off Bombay (Maharashtra, India) and adjacent waters during the 48th cruise of @iORV Sagar Kanya@@ in December 1988 to January 1989...

Demonstration of a robust magnonic spin wave interferometer.

Science.gov (United States)

Kanazawa, Naoki; Goto, Taichi; Sekiguchi, Koji; Granovsky, Alexander B; Ross, Caroline A; Takagi, Hiroyuki; Nakamura, Yuichi; Inoue, Mitsuteru

2016-07-22

Magnonics is an emerging field dealing with ultralow power consumption logic circuits, in which the flow of spin waves, rather than electric charges, transmits and processes information. Waves, including spin waves, excel at encoding information via their phase using interference. This enables a number of inputs to be processed in one device, which offers the promise of multi-input multi-output logic gates. To realize such an integrated device, it is essential to demonstrate spin wave interferometers using spatially isotropic spin waves with high operational stability. However, spin wave reflection at the waveguide edge has previously limited the stability of interfering waves, precluding the use of isotropic spin waves, i.e., forward volume waves. Here, a spin wave absorber is demonstrated comprising a yttrium iron garnet waveguide partially covered by gold. This device is shown experimentally to be a robust spin wave interferometer using the forward volume mode, with a large ON/OFF isolation value of 13.7 dB even in magnetic fields over 30 Oe.

Single spin asymmetry for charm mesons

Energy Technology Data Exchange (ETDEWEB)

Dominguez Zacarias, G. [PIMAyC, Eje Central Lazaro Cardenas No. 152, Apdo. Postal 14-805, D.F. (Mexico); Herrera, G.; Mercado, J. [Centro de Investigacion y de Estudios Avanzados, Apdo. Postal 14-740, D.F. (Mexico)

2007-08-15

We study single spin asymmetries of D{sup 0} and D{sup -} mesons in polarized proton-proton collisions. A two component model is used to describe charm meson production. The production of D mesons occurs by recombination of the constituents present in the initial state as well as by fragmentation of quarks in the final state. This model has proved to describe the production of charm. The recombination component involves a mechanism of spin alignment that ends up in a single spin asymmetry. Experimental measurements of single spin asymmetry for pions at RHIC are compared with the model. Predictions for the asymmetry in D mesons are presented. (orig.)

Single spin asymmetry for charm mesons

International Nuclear Information System (INIS)

Dominguez Zacarias, G.; Herrera, G.; Mercado, J.

2007-01-01

We study single spin asymmetries of D 0 and D - mesons in polarized proton-proton collisions. A two component model is used to describe charm meson production. The production of D mesons occurs by recombination of the constituents present in the initial state as well as by fragmentation of quarks in the final state. This model has proved to describe the production of charm. The recombination component involves a mechanism of spin alignment that ends up in a single spin asymmetry. Experimental measurements of single spin asymmetry for pions at RHIC are compared with the model. Predictions for the asymmetry in D mesons are presented. (orig.)

All-spin logic operations: Memory device and reconfigurable computing

Science.gov (United States)

Patra, Moumita; Maiti, Santanu K.

2018-02-01

Exploiting spin degree of freedom of electron a new proposal is given to characterize spin-based logical operations using a quantum interferometer that can be utilized as a programmable spin logic device (PSLD). The ON and OFF states of both inputs and outputs are described by spin state only, circumventing spin-to-charge conversion at every stage as often used in conventional devices with the inclusion of extra hardware that can eventually diminish the efficiency. All possible logic functions can be engineered from a single device without redesigning the circuit which certainly offers the opportunities of designing new generation spintronic devices. Moreover, we also discuss the utilization of the present model as a memory device and suitable computing operations with proposed experimental setups.

Application of off-specular polarized neutron reflectometry to measurements on an array of mesoscopic ferromagnetic disks

International Nuclear Information System (INIS)

Temst, K.; Van Bael, M. J.; Fritzsche, H.

2001-01-01

Using off-specular polarized neutron reflectometry with neutron spin analysis, we determined the magnetic properties of a large array of in-plane magnetized ferromagnetic Co disks. Resonant peaks are clearly observed in the off-specular reflectivity, due to the lateral periodicity of the disk array. Using polarized neutrons, the intensity of the resonant peak in the off-specular reflectivity is studied as a function of the magnetic field applied in the sample plane. Spin analysis of the reflected neutrons reveals the magnetization reversal and saturation within the disks. copyright 2001 American Institute of Physics

Theoretical Overview on Recent Developments in Transverse Spin Physics

International Nuclear Information System (INIS)

Yuan, Feng

2009-01-01

Transverse-spin physics has been very active and rapidly developing in the last few years. In this talk, I will briefly summarize recent theoretical developments, focusing on the associated QCD dynamics in transverse spin physics

Breakdown of Spin-Waves in Anisotropic Magnets: Spin Dynamics in α-RuCl3

Science.gov (United States)

Winter, Stephen; Riedl, Kira; Honecker, Andreas; Valenti, Roser

α -RuCl3 has recently emerged as a promising candidate for realizing the hexagonal Kitaev model in a real material. Similar to the related iridates (e.g. Na2IrO3), complex magnetic interactions arise from a competition between various similar energy scales, including spin-orbit coupling (SOC), Hund's coupling, and crystal-field splitting. Due to this complexity, the correct spin Hamiltonians for such systems remain hotly debated. For α-RuCl3, a combination of ab-initio calculations, microscopic considerations, and analysis of the static magnetic response have suggested off-diagonal couplings (Γ ,Γ') and long-range interactions in addition to the expected Kitaev exchange. However, the effect of such additional terms on the dynamic response remains unclear. In this contribution, we discuss the recently measured inelastic neutron scattering response in the context of realistic proposals for the microscopic spin Hamiltonian. We conclude that the observed scattering continuum, which has been taken as a signature of Kitaev spin liquid physics, likely persists over a broad range of parameters.

Ultra-high mobility transparent organic thin film transistors grown by an off-centre spin-coating method.

Science.gov (United States)

Yuan, Yongbo; Giri, Gaurav; Ayzner, Alexander L; Zoombelt, Arjan P; Mannsfeld, Stefan C B; Chen, Jihua; Nordlund, Dennis; Toney, Michael F; Huang, Jinsong; Bao, Zhenan

2014-01-01

Organic semiconductors with higher carrier mobility and better transparency have been actively pursued for numerous applications, such as flat-panel display backplane and sensor arrays. The carrier mobility is an important figure of merit and is sensitively influenced by the crystallinity and the molecular arrangement in a crystal lattice. Here we describe the growth of a highly aligned meta-stable structure of 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) from a blended solution of C8-BTBT and polystyrene by using a novel off-centre spin-coating method. Combined with a vertical phase separation of the blend, the highly aligned, meta-stable C8-BTBT films provide a significantly increased thin film transistor hole mobility up to 43 cm(2) Vs(-1) (25 cm(2) Vs(-1) on average), which is the highest value reported to date for all organic molecules. The resulting transistors show high transparency of >90% over the visible spectrum, indicating their potential for transparent, high-performance organic electronics.

Nonlinear stability of spin-flip excitations

International Nuclear Information System (INIS)

Arunasalam, V.

1975-01-01

A rather complete discussion of the nonlinear electrodynamic behavior of a negative-temperature spin system is presented. The method presented here is based on a coupled set of master equations, one describing the time evolution of the photon (i.e., the spin-flip excitation) distribution function and the other describing the time evolution of the particle distribution function. It is found that the initially unstable (i.e., growing) spin-flip excitations grow to such a large amplitude that their nonlinear reaction on the particle distribution function becomes important. It is then shown that the initially totally inverted two-level spin system evolves rapidly (through this nonlinear photon-particle coupling) towards a quasilinear steady state where the populations of the spin-up and the spin-down states are equal to each other. Explicit expressions for the time taken to reach this quasilinear steady state and the energy in the spin-flip excitations at this state are also presented

Spin-off from particle detectors in the field of medicine and biology

International Nuclear Information System (INIS)

Lecoq, P.

2007-01-01

Since the discovery of X-rays by Roentgen in 1895 physicists have played a major role in the development of medical imaging instrumentation. More recently, the technological developments in several areas of applied physics, the new generation of particle physics detectors and the development of an information-based society all combine to enhance the performance of presently available imaging devices. This paper describes the critical parameters of modern medical imaging in the context of the spectacular development of in-vivo molecular imaging, which will soon allow to bridge post-genomics research activities with new diagnostics and therapeutic strategies for major diseases. In particular, the molecular profiling of tumors and gene expression open the way to tailored therapies and therapeutic monitoring of major diseases like cancer, degenerative and genetic disorders. Moreover, the repeatability of non-invasive approaches allows an evaluation of drug targeting and pharmacokinetics studies on small animals, as well as a precise screening and treatment follow-up of patients. The technical requirements on imaging devices are very challenging but are rather similar in many respects to the ones of modern particle detectors on high-luminosity accelerators. Examples will be given of active technology transfer areas from high-energy physics detectors, which can significantly improve the performance of future medical imaging devices. Special emphasis will be put on the need for a globalization of technology research and development as modern instrumentation in a vast range of applications has similar requirements and spin-off should be more and more understood as cross-fertilization between different disciplines

Spin-off from particle detectors in the field of medicine and biology

Energy Technology Data Exchange (ETDEWEB)

Lecoq, P. [CERN, 1211 Geneva (Switzerland)], E-mail: paul.lecoq@cern.ch

2007-10-21

Since the discovery of X-rays by Roentgen in 1895 physicists have played a major role in the development of medical imaging instrumentation. More recently, the technological developments in several areas of applied physics, the new generation of particle physics detectors and the development of an information-based society all combine to enhance the performance of presently available imaging devices. This paper describes the critical parameters of modern medical imaging in the context of the spectacular development of in-vivo molecular imaging, which will soon allow to bridge post-genomics research activities with new diagnostics and therapeutic strategies for major diseases. In particular, the molecular profiling of tumors and gene expression open the way to tailored therapies and therapeutic monitoring of major diseases like cancer, degenerative and genetic disorders. Moreover, the repeatability of non-invasive approaches allows an evaluation of drug targeting and pharmacokinetics studies on small animals, as well as a precise screening and treatment follow-up of patients. The technical requirements on imaging devices are very challenging but are rather similar in many respects to the ones of modern particle detectors on high-luminosity accelerators. Examples will be given of active technology transfer areas from high-energy physics detectors, which can significantly improve the performance of future medical imaging devices. Special emphasis will be put on the need for a globalization of technology research and development as modern instrumentation in a vast range of applications has similar requirements and spin-off should be more and more understood as cross-fertilization between different disciplines.

Spin-crossover behavior of polymeric iron(III) complexes

International Nuclear Information System (INIS)

Maeda, Yonezo; Miyamoto, Makoto; Takashima, Yoshimasa; Oshio, Hiroaki

1989-01-01

Polymeric spin-crossover iron(III) complexes possessing poly(4-vinylpyridine), poly(N-vinylimidazole) or poly(octylmethacrylate-co-4-vinylpyridine) as ligand are prepared. In this experience enriched 57 Fe was used to get strong Moessbauer absorption. The enriched behavior of the complexes were examined by magnetic susceptibilities measurement, and Moessbauer and esr spectroscopies. Some of them show spin-state behavior over a wide range of temperature. Some of them show rapid spin-state interexchange compared to the Moessbauer time scale and others not. Spin-crossover behavior of polymeric complexes is characterized of wide spin-state transition temperature range

Influence of Mn incorporation for Ni on the magnetocaloric properties of rapidly solidified off-stoichiometric NiMnGa ribbons

Energy Technology Data Exchange (ETDEWEB)

Dey, Sushmita; Singh, Satnam; Roy, R.K.; Ghosh, M.; Mitra, A.; Panda, A.K., E-mail: akpanda@nmlindia.org

2016-01-01

The present investigation addresses the magnetocaloric behaviour in a series of Ni{sub 77−x}Mn{sub x}Ga{sub 23} (x=23, 24, 25, 27 and 29) rapidly solidified alloys prepared in the form of ribbons by melt spinning technique. The approach of the study is to identify the off-stoichiometric composition wherein room temperature magneto-structural transformation is achieved. The alloy chemistry was tailored through Mn incorporation for Ni such that the magnetic and structural transitions were at close proximity to achieve highest entropy value of ΔS equal to 8.51 J Kg{sup −1} K{sup −1} for #Mn{sub 24} ribbon measured at an applied field of 3 T. When such transitions are more staggered as in #Mn{sub 29} the entropy value of ribbon reduced to as low as 1.61 J Kg{sup −1} K{sup −1}. Near room temperature transformations in #Mn{sub 24} ribbon have been observed through calorimetric and thermomagnetic evaluation. Reverse martensitic transformation (martensite→autstenite) temperature indicates not only distinct change in the saturation flux density but also an inter-martensitic phase. Microstructural analysis of #Mn{sub 24} alloy ribbon revealed structural ordering with the existence of plate morphology evidenced for martensitic phase. - Highlights: • Magnetocaloric effect in a series of melt spun NiMnGa ribbon is addressed. • The alloy series revealed austenitic state as well as its presence with martensite. • The morphology of the ribbons has been shown and discussed through phase analysis. • Influence of magnetising field on entropy and relative cooling power is discussed. • Influence of intermartensitic state on magnetization plots have also been shown.

Fast spin-echo imaging

International Nuclear Information System (INIS)

Mackey, K.; Zoarski, G.; Bentson, J.R.; Lufkin, R.B.; Melki, P.; Jolesz, F.

1991-01-01

This paper reports on a partial radio-frequency (RF) echo-planar pulse sequence called contiguous slice fast spin echo (CSFSE) which is undergoing clinical trials for spine MR imaging. In this variation of rapid acquisition relaxation enhanced (RARE) spin-echo imaging, rapid 180 degrees RF pulse generated refocused echoes, producing T2-weighted images in about one-third the time of conventional double-echo technique. Forty patients with suspected pathology of the spine were imaged with conventional double-echo and closely matched CSFSE techniques on a GE Signa 1.5-T Advantage system. Cases were reviewed by two board-certified neuroradiologists. In all cases the CSFSE images were of equal or superior quality compared with those obtained with the conventional double-echo technique. Pathologic processes that were imaged consisted of inflammatory, neoplastic, posttraumatic, and degenerative conditions

Large-xF spin asymmetry in π0 production by 200-GeV polarized protons

International Nuclear Information System (INIS)

Adams, D.L.; Corcoran, M.D.; Cranshaw, J.; Nessi-Tedaldi, F.; Nessi, M.; Nguyen, C.; Roberts, J.B.; Skeens, J.; White, J.L.; Bystricky, J.; Lehar, F.; Lesquen, A. de; Cossairt, J.D.; Read, A.L.; En'yo, H.; Funahashi, H.; Goto, Y.; Imai, K.; Itow, Y.; Makino, S.; Masaike, A.; Miyake, K.; Nagamine, T.; Saito, N.; Yamashita, S.; Iwatani, K.; Krueger, K.W.; Kuroda, K.; Michalowicz, A.; Luehring, F.C.; Miller, D.H.; Pauletta, G.; Penzo, A.; Schiavon, P.; Zanetti, A.; Salvato, G.; Villari, A.; Takeutchi, F.; Tamura, N.; Tanaka, N.; Yoshida, T.

1992-01-01

The spin asymmetry A N for inclusive π 0 production by 200-GeV transversely-polarized protons on a liquid hydrogen target has been measured at Fermilab over a wide range of x F , with 0.5 T F >0.3, the asymmetry rises with increasing x F and reaches a value of A N =0.15±0.03 in the region 0.6 F <0.8. This result provides new input regarding the question of the internal spin structure of transversely-polarized protons. (orig.)

SPIN-selling

CERN Document Server

Rackham, Neil

1995-01-01

True or false? In selling high-value products or services: "closing" increases your chance of success; it is essential to describe the benefits of your product or service to the customer; objection handling is an important skill; and open questions are more effective than closed questions. All false, says Neil Rackham. He and his team studied more than 35,000 sales calls made by 10,000 sales people in 23 countries over 12 years. Their findings revealed that many of the methods developed for selling low-value goods just don't work for major sales. Rackham went on to introduce his SPIN-selling method, where SPIN describes the whole selling process - Situation questions, Problem questions, Implication questions, Need-payoff questions. SPIN-selling provides you with a set of simple and practical techniques which have been tried in many of today's leading companies with dramatic improvements to their sales performance.

Influence of primary fragment excitation energy and spin distributions on fission observables

Science.gov (United States)

Litaize, Olivier; Thulliez, Loïc; Serot, Olivier; Chebboubi, Abdelaziz; Tamagno, Pierre

2018-03-01

Fission observables in the case of 252Cf(sf) are investigated by exploring several models involved in the excitation energy sharing and spin-parity assignment between primary fission fragments. In a first step the parameters used in the FIFRELIN Monte Carlo code "reference route" are presented: two parameters for the mass dependent temperature ratio law and two constant spin cut-off parameters for light and heavy fragment groups respectively. These parameters determine the initial fragment entry zone in excitation energy and spin-parity (E*, Jπ). They are chosen to reproduce the light and heavy average prompt neutron multiplicities. When these target observables are achieved all other fission observables can be predicted. We show here the influence of input parameters on the saw-tooth curve and we discuss the influence of a mass and energy-dependent spin cut-off model on gamma-rays related fission observables. The part of the model involving level densities, neutron transmission coefficients or photon strength functions remains unchanged.

Photonic spin Hall effect at metasurfaces.

Science.gov (United States)

Yin, Xiaobo; Ye, Ziliang; Rho, Junsuk; Wang, Yuan; Zhang, Xiang

2013-03-22

The spin Hall effect (SHE) of light is very weak because of the extremely small photon momentum and spin-orbit interaction. Here, we report a strong photonic SHE resulting in a measured large splitting of polarized light at metasurfaces. The rapidly varying phase discontinuities along a metasurface, breaking the axial symmetry of the system, enable the direct observation of large transverse motion of circularly polarized light, even at normal incidence. The strong spin-orbit interaction deviates the polarized light from the trajectory prescribed by the ordinary Fermat principle. Such a strong and broadband photonic SHE may provide a route for exploiting the spin and orbit angular momentum of light for information processing and communication.

Industrial-strength ecology: trade-offs and opportunities in algal biofuel production.

Science.gov (United States)

Shurin, Jonathan B; Abbott, Rachel L; Deal, Michael S; Kwan, Garfield T; Litchman, Elena; McBride, Robert C; Mandal, Shovon; Smith, Val H

2013-11-01

Microalgae represent one of the most promising groups of candidate organisms for replacing fossil fuels with contemporary primary production as a renewable source of energy. Algae can produce many times more biomass per unit area than terrestrial crop plants, easing the competing demands for land with food crops and native ecosystems. However, several aspects of algal biology present unique challenges to the industrial-scale aquaculture of photosynthetic microorganisms. These include high susceptibility to invading aquatic consumers and weeds, as well as prodigious requirements for nutrients that may compete with the fertiliser demands of other crops. Most research on algal biofuel technologies approaches these problems from a cellular or genetic perspective, attempting either to engineer or select algal strains with particular traits. However, inherent functional trade-offs may limit the capacity of genetic selection or synthetic biology to simultaneously optimise multiple functional traits for biofuel productivity and resilience. We argue that a community engineering approach that manages microalgal diversity, species composition and environmental conditions may lead to more robust and productive biofuel ecosystems. We review evidence for trade-offs, challenges and opportunities in algal biofuel cultivation with a goal of guiding research towards intensifying bioenergy production using established principles of community and ecosystem ecology. © 2013 John Wiley & Sons Ltd/CNRS.

Current-induced torques and interfacial spin-orbit coupling

KAUST Repository

Haney, Paul M.; Lee, Hyun-Woo; Lee, Kyung-Jin; Manchon, Aurelien; Stiles, M. D.

2013-01-01

In bilayer systems consisting of an ultrathin ferromagnetic layer adjacent to a metal with strong spin-orbit coupling, an applied in-plane current induces torques on the magnetization. The torques that arise from spin-orbit coupling are of particular interest. Here we use first-principles methods to calculate the current-induced torque in a Pt-Co bilayer to help determine the underlying mechanism. We focus exclusively on the analog to the Rashba torque, and do not consider the spin Hall effect. The details of the torque depend strongly on the layer thicknesses and the interface structure, providing an explanation for the wide variation in results found by different groups. The torque depends on the magnetization direction in a way similar to that found for a simple Rashba model. Artificially turning off the exchange spin splitting and separately the spin-orbit coupling potential in the Pt shows that the primary source of the “fieldlike” torque is a proximate spin-orbit effect on the Co layer induced by the strong spin-orbit coupling in the Pt.

Current-induced torques and interfacial spin-orbit coupling

KAUST Repository

Haney, Paul M.

2013-12-19

In bilayer systems consisting of an ultrathin ferromagnetic layer adjacent to a metal with strong spin-orbit coupling, an applied in-plane current induces torques on the magnetization. The torques that arise from spin-orbit coupling are of particular interest. Here we use first-principles methods to calculate the current-induced torque in a Pt-Co bilayer to help determine the underlying mechanism. We focus exclusively on the analog to the Rashba torque, and do not consider the spin Hall effect. The details of the torque depend strongly on the layer thicknesses and the interface structure, providing an explanation for the wide variation in results found by different groups. The torque depends on the magnetization direction in a way similar to that found for a simple Rashba model. Artificially turning off the exchange spin splitting and separately the spin-orbit coupling potential in the Pt shows that the primary source of the “fieldlike” torque is a proximate spin-orbit effect on the Co layer induced by the strong spin-orbit coupling in the Pt.

Electrical manipulation of dynamic magnetic impurity and spin texture of helical Dirac fermions

Science.gov (United States)

Wang, Rui-Qiang; Zhong, Min; Zheng, Shi-Han; Yang, Mou; Wang, Guang-Hui

2016-05-01

We have theoretically investigated the spin inelastic scattering of helical electrons off a high-spin nanomagnet absorbed on a topological surface. The nanomagnet is treated as a dynamic quantum spin and driven by the spin transfer torque effect. We proposed a mechanism to electrically manipulate the spin texture of helical Dirac fermions rather than by an external magnetic field. By tuning the bias voltage and the direction of impurity magnetization, we present rich patterns of spin texture, from which important fingerprints exclusively associated with the spin helical feature are obtained. Furthermore, it is found that the nonmagnetic potential can create the resonance state in the spin density with different physics as the previously reported resonance of charge density.

Polarization of nuclear spins by a cold nanoscale resonator

International Nuclear Information System (INIS)

Butler, Mark C.; Weitekamp, Daniel P.

2011-01-01

A cold nanoscale resonator coupled to a system of nuclear spins can induce spin relaxation. In the low-temperature limit where spin-lattice interactions are ''frozen out,'' spontaneous emission by nuclear spins into a resonant mechanical mode can become the dominant mechanism for cooling the spins to thermal equilibrium with their environment. We provide a theoretical framework for the study of resonator-induced cooling of nuclear spins in this low-temperature regime. Relaxation equations are derived from first principles, in the limit where energy donated by the spins to the resonator is quickly dissipated into the cold bath that damps it. A physical interpretation of the processes contributing to spin polarization is given. For a system of spins that have identical couplings to the resonator, the interaction Hamiltonian conserves spin angular momentum, and the resonator cannot relax the spins to thermal equilibrium unless this symmetry is broken by the spin Hamiltonian. The mechanism by which such a spin system becomes ''trapped'' away from thermal equilibrium can be visualized using a semiclassical model, which shows how an indirect spin-spin interaction arises from the coupling of multiple spins to one resonator. The internal spin Hamiltonian can affect the polarization process in two ways: (1) By modifying the structure of the spin-spin correlations in the energy eigenstates, and (2) by splitting the degeneracy within a manifold of energy eigenstates, so that zero-frequency off-diagonal terms in the density matrix are converted to oscillating coherences. Shifting the frequencies of these coherences sufficiently far from zero suppresses the development of resonator-induced correlations within the manifold during polarization from a totally disordered state. Modification of the spin-spin correlations by means of either mechanism affects the strength of the fluctuating spin dipole that drives the resonator. In the case where product states can be chosen as energy

Electromagnetic production of strangeness and {eta} mesons on simple hadronic systems; Production electromagnetique d`etrangete et de mesons {eta} sur les systemes hadroniques simples

Energy Technology Data Exchange (ETDEWEB)

Fayard, C.; Lamot, G.H.; Rouvier, F. [Inst. de Physique Nucleaire, Lyon-1 Univ., 69 - Villeurbanne (France); Kerbicov, B. [Inst. Teoreticheskoj i Eksperimental`noj Fiziki, Moscow (Russian Federation); Collaboration: VPI/USA, DAPNIA

1998-12-31

We investigate the photo- and electro-production of strangeness of the proton and deuteron, based upon effective hadronic Lagrangians. The so called off-shell effects inherent to the fermions with spin {>=}3/2 is carefully studied. This formalism is now extended to the reaction {gamma}p {yields} {eta}p. (authors)

Spin correlation in t anti t production from p anti p collisions at √s = 1.8 TeV

International Nuclear Information System (INIS)

Suyong Choi

2000-01-01

The Standard Model predicts that the lifetime of the top quark is shorter than the typical time scale at which hadronization process occurs, and the spin information at its production is preserved. Spin correlation of the t anti t system from p anti p collisions at the Tevatron is analyzed using 6 events in the dilepton channels collected using the D0 detector. Spin correlation factor of κ > minus 0.25 at 68% CL is obtained from the data

High-spin states in 82Sr

International Nuclear Information System (INIS)

Baktash, C.; Halper, M.L.; Garcia Bermudez, G.J.

1989-01-01

As recent theoretical calculations that predicted the onset of superdeformation in the A ≅ 80 region, the 52 Cr( 34 S,2p2n) reaction at 130 MeV beam energy was employed to populate the high-spin states in 82 Sr. The detection system consisted of the ORNL Compton-Suppression Spectrometer System (18 Ge detectors), the Spin Spectrometer, and the 4 φ CsI Dwarf Ball of Washington University. Off-line analysis of the proton-gated data resulted in nearly 170 million Ge-Ge pairs, which were mostly due to the 2p2n channel. A decay scheme extending to spin I=27h has been established. No strong evidence for the presence of superdeformed states in 82 Sr was found in a preliminary analysis of the data. (Author) [es

Kinetics of rapid covalent bond formation of aniline with humic acid: ESR investigations with nitroxide spin labels

Science.gov (United States)

Glinka, Kevin; Matthies, Michael; Theiling, Marius; Hideg, Kalman; Steinhoff, Heinz-Jürgen

2016-04-01

Sulfonamide antibiotics used in livestock farming are distributed to farmland by application of slurry as fertilizer. Previous work suggests rapid covalent binding of the aniline moiety to humic acids found in soil. In the current work, kinetics of this binding were measured in X-band EPR spectroscopy by incubating Leonardite humic acid (LHA) with a paramagnetic aniline spin label (anilino-NO (2,5,5-Trimethyl-2-(3-aminophenyl)pyrrolidin-1-oxyl)). Binding was detected by a pronounced broadening of the spectral lines after incubation of LHA with anilino-NO. The time evolution of the amplitude of this feature was used for determining the reaction kinetics. Single- and double-exponential models were fitted to the data obtained for modelling one or two first-order reactions. Reaction rates of 0.16 min-1 and 0.012 min-1, were found respectively. Addition of laccase peroxidase did not change the kinetics but significantly enhanced the reacting fraction of anilino-NO. This EPR-based method provides a technically simple and effective method for following rapid binding processes of a xenobiotic substance to humic acids.

Screening for social phobia in medical in- and outpatients with the German version of the Social Phobia Inventory (SPIN).

Science.gov (United States)

Sosic, Z; Gieler, U; Stangier, U

2008-06-01

To evaluate the German version of the Social Phobia Inventory (SPIN) as a screening device and to report corresponding cut-off scores for different populations. In Study 1, 2043 subjects from a representative sample completed the SPIN. Cut-off values were established on the basis of means and standard deviations. In Study 2, different aspects of validity were examined in a clinical sample comprising 164 subjects, including social phobic individuals, individuals with other anxiety disorders and depression, and non-clinical control subjects. Internal consistency was evaluated. Convergent and divergent validity were explored using several established measures. Finally, the sensitivity and specificity of the German SPIN with regard to social anxiety classification were investigated by means of receiver operating characteristics (ROC) analyses. In Study 1, mean scores and standard deviations were used to determine cut-off scores for the German SPIN. In Study 2, excellent internal consistency and good convergent and divergent validity were obtained. ROC analyses revealed that the German SPIN performed well in discriminating between social phobic individuals on the one hand and psychiatric and non-psychiatric controls on the other. A cut-off score of 25 represented the best balance between sensitivity and specificity. Comparable to the original version, the German SPIN demonstrates solid psychometric properties and shows promise as an economic, reliable, and valid screening device.

Spin-drift transport in semiconductors

Energy Technology Data Exchange (ETDEWEB)

Miah, M Idrish [Nanoscale Science and Technology Centre and School of Biomolecular and Physical Sciences, Griffith University, Nathan, Brisbane, QLD 4111 (Australia); Department of Physics, University of Chittagong, Chittagong, Chittagong-4331 (Bangladesh)

2008-02-07

We present a study on spin transport in semiconductors under applied electric fields. Our experiments detect photoinjected electron spins and their relaxation during drift transport in intrinsic and moderately n-doped GaAs, based on the extraordinary Hall (eH) effect. For relatively low electric field (E), the optically spin-induced eH effect in n-doped GaAs is found to be enhanced with increasing doping density and not to depend much on E, indicating that a substantial amount of optical spin polarization is preserved during the drift transport in these extrinsic semiconductors. However, when the spin-oriented electrons are injected with a high E, a very significant decrease is observed in the eH voltage (V{sub eH}) due to an increase in the spin precession frequency of the hot electrons. Spin relaxation by the D'yakonov-Perel' mechanism is calculated, and is suggested to be the reason for such a rapid spin relaxation for hot electrons under a high E. However, in an intrinsic GaAs (i-GaAs), a much weaker V{sub eH} is observed and, as the electron spins scattered by holes due to the Coulomb interaction in i-GaAs, the spin relaxation by the Bir-Aronov-Pikus mechanism is considered. Skew scattering and side jump as possible mechanisms of the optically spin-induced transverse Hall currents are discussed. Based on a spin drift-diffusion model, drift and diffusion contributions to the V{sub eH} are examined. The results are also discussed in comparison with theoretical investigations.

Spin valve sensor for biomolecular identification: Design, fabrication, and characterization

Science.gov (United States)

Li, Guanxiong

Biomolecular identification, e.g., DNA recognition, has broad applications in biology and medicine such as gene expression analysis, disease diagnosis, and DNA fingerprinting. Therefore, we have been developing a magnetic biodetection technology based on giant magnetoresistive spin valve sensors and magnetic nanoparticle (developed for the magnetic nanoparticle detection, assuming the equivalent average field of magnetic nanoparticles and the coherent rotation of spin valve free layer magnetization. Micromagnetic simulations have also been performed for the spin valve sensors. The analytical model and micromagnetic simulations are found consistent with each other and are in good agreement with experiments. The prototype spin valve sensors have been fabricated at both micron and submicron scales. We demonstrated the detection of a single 2.8-mum magnetic microbead by micron-sized spin valve sensors. Based on polymer-mediated self-assembly and fine lithography, a bilayer lift-off process was developed to deposit magnetic nanoparticles onto the sensor surface in a controlled manner. With the lift-off deposition method, we have successfully demonstrated the room temperature detection of monodisperse 16-nm Fe3O 4 nanoparticles in a quantity from a few tens to several hundreds by submicron spin valve sensors, proving the feasibility of the nanoparticle detection. As desired for quantitative biodetection, a fairly linear dependence of sensor signal on the number of nanoparticles has been confirmed. The initial detection of DNA hybridization events labeled by magnetic nanoparticles further proved the magnetic biodetection concept.

Ion cyclotron and spin-flip emissions from fusion products in tokamaks

International Nuclear Information System (INIS)

Arunasalam, V.; Greene, G.J.; Young, K.M.

1993-02-01

Power emission by fusion products of tokamak plasmas in their ion cyclotron range of frequencies (ICRF) and at their spin-flip resonance frequency is calculated for some specific model fusion product velocity-space distribution functions. The background plasma of say deuterium (D) is assumed to be in equilibrium with a Maxwellian distribution both for the electrons and ions. The fusion product velocity distributions analyzed here are: (1) A monoenergetic velocity space ring distribution. (2) A monoenergetic velocity space spherical shell distribution. (3) An anisotropic Maxwellian distribution with T perpendicular ≠ T parallel and with appreciable drift velocity along the confining magnetic field. Single ''dressed'' test particle spontaneous emission calculations are presented first and the radiation temperature for ion cyclotron emission (ICE) is analyzed both for black-body emission and nonequilibrium conditions. Thresholds for instability and overstability conditions are then examined and quasilinear and nonlinear theories of the electromagnetic ion cyclotron modes are discussed. Distinctions between ''kinetic or causal instabilities'' and ''hydrodynamic instabilities'' are drawn and some numerical estimates are presented for typical tokamak parameters. Semiquantitative remarks are offered on wave accessibility, mode conversion, and parametric decay instabilities as possible for spatially localized ICE. Calculations are carried out both for k parallel = 0 for k parallel ≠ 0. The effects of the temperature anisotropy and large drift velocities in the parallel direction are also examined. Finally, proton spin-flip resonance emission and absorption calculations are also presented both for thermal equilibrium conditions and for an ''inverted'' population of states

Ion cyclotron and spin-flip emissions from fusion products in tokamaks

Energy Technology Data Exchange (ETDEWEB)

Arunasalam, V.; Greene, G.J.; Young, K.M.

1993-02-01

Power emission by fusion products of tokamak plasmas in their ion cyclotron range of frequencies (ICRF) and at their spin-flip resonance frequency is calculated for some specific model fusion product velocity-space distribution functions. The background plasma of say deuterium (D) is assumed to be in equilibrium with a Maxwellian distribution both for the electrons and ions. The fusion product velocity distributions analyzed here are: (1) A monoenergetic velocity space ring distribution. (2) A monoenergetic velocity space spherical shell distribution. (3) An anisotropic Maxwellian distribution with T [perpendicular] [ne] T[parallel]and with appreciable drift velocity along the confining magnetic field. Single dressed'' test particle spontaneous emission calculations are presented first and the radiation temperature for ion cyclotron emission (ICE) is analyzed both for black-body emission and nonequilibrium conditions. Thresholds for instability and overstability conditions are then examined and quasilinear and nonlinear theories of the electromagnetic ion cyclotron modes are discussed. Distinctions between kinetic or causal instabilities'' and hydrodynamic instabilities'' are drawn and some numerical estimates are presented for typical tokamak parameters. Semiquantitative remarks are offered on wave accessibility, mode conversion, and parametric decay instabilities as possible for spatially localized ICE. Calculations are carried out both for k[parallel] = 0 for k[parallel] [ne] 0. The effects of the temperature anisotropy and large drift velocities in the parallel direction are also examined. Finally, proton spin-flip resonance emission and absorption calculations are also presented both for thermal equilibrium conditions and for an inverted'' population of states.

Inovação como transição: uma abordagem para o planejamento e desenvolvimento de spin-offs acadêmicos

Directory of Open Access Journals (Sweden)

Leonardo Augusto de Vasconcelos Gomes

2016-03-01

Full Text Available Spin-off acadêmico é um tipo de nova firma que, geralmente, nasce para explorar uma inovação radical capaz de criar um novo mercado ou desafiar as regras de um setor estabelecido. Fundamentado em uma combinação de pesquisa bibliográfica, estudos de múltiplos casos e intervenções à luz da pesquisa-ação, este trabalho objetiva contribuir para a literatura de inovação e empreendedorismo em dois aspectos. Primeiro, propõe o conceito de inovação como transição em três dimensões: grau (desvio em relação a um aspecto, extensão (número de aspectos e atores envolvidos e trajetória (sequência de inovações ao longo do tempo. A segunda contribuição é a construção de umframework com estrutura não linear e recursiva que integra a inovação ao planejamento e ao desenvolvimento do spin-offabordando o gerenciamento das incertezas. Finalmente, conclui-se que oframework proposto pode auxiliar empreendedores, investidores e universidades no desafio de criar empresas para explorar uma inovação radical.

Magnetic pseudo-fields in a rotating electron-nuclear spin system

Science.gov (United States)

Wood, A. A.; Lilette, E.; Fein, Y. Y.; Perunicic, V. S.; Hollenberg, L. C. L.; Scholten, R. E.; Martin, A. M.

2017-11-01

Analogous to the precession of a Foucault pendulum observed on the rotating Earth, a precessing spin observed in a rotating frame of reference appears frequency-shifted. This can be understood as arising from a magnetic pseudo-field in the rotating frame that nevertheless has physically significant consequences, such as the Barnett effect. To detect these pseudo-fields, a rotating-frame sensor is required. Here we use quantum sensors, nitrogen-vacancy (NV) centres, in a rapidly rotating diamond to detect pseudo-fields in the rotating frame. Whereas conventional magnetic fields induce precession at a rate proportional to the gyromagnetic ratio, rotation shifts the precession of all spins equally, and thus primarily affect 13C nuclear spins in the sample. We are thus able to explore these effects via quantum sensing in a rapidly rotating frame, and define a new approach to quantum control using rotationally induced nuclear spin-selective magnetic fields. This work provides an integral step towards realizing precision rotation sensing and quantum spin gyroscopes.

Detection of cut-off point for rapid automized naming test in good readers and dyslexics

Directory of Open Access Journals (Sweden)

Zahra Soleymani

2014-01-01

Full Text Available Background and Aim: Rapid automized naming test is an appropriate tool to diagnose learning disability even before teaching reading. This study aimed to detect the cut-off point of this test for good readers and dyslexics.Methods: The test has 4 parts including: objects, colors, numbers and letters. 5 items are repeated on cards randomly for 10 times. Children were asked to name items rapidly. We studied 18 dyslexic students and 18 age-matched good readers between 7 and 8 years of age at second and third grades of elementary school; they were recruited by non-randomize sampling into 2 groups: children with developmental dyslexia from learning disabilities centers with mean age of 100 months, and normal children with mean age of 107 months from general schools in Tehran. Good readers selected from the same class of dyslexics.Results: The area under the receiver operating characteristic curve was 0.849 for letter naming, 0.892 for color naming, 0.971 for number naming, 0.887 for picture naming, and 0.965 totally. The overall sensitivity and specificity was 1 and was 0.79, respectively. The highest sensitivity and specificity were related to number naming (1 and 0.90, respectively.Conclusion: Findings showed that the rapid automized naming test could diagnose good readers from dyslexics appropriately.

Transportation cost of nuclear off-peak power for hydrogen production based on water electrolysis

International Nuclear Information System (INIS)

Shimizu, Saburo; Ueno, Shuichi

2004-01-01

The paper describes transportation cost of the nuclear off-peak power for a hydrogen production based on water electrolysis in Japan. The power could be obtainable by substituting hydropower and/or fossil fueled power supplying peak and middle demands with nuclear power. The transportation cost of the off-peak power was evaluated to be 1.42 yen/kWh when an electrolyser receives the off-peak power from a 6kV distribution wire. Marked reduction of the cost was caused by the increase of the capacity factor. (author)

Effects of oncoming target velocities on rapid force production and accuracy of force production intensity and timing.

Science.gov (United States)

Ohta, Yoichi

2017-12-01

The present study aimed to clarify the effects of oncoming target velocities on the ability of rapid force production and accuracy and variability of simultaneous control of both force production intensity and timing. Twenty male participants (age: 21.0 ± 1.4 years) performed rapid gripping with a handgrip dynamometer to coincide with the arrival of an oncoming target by using a horizontal electronic trackway. The oncoming target velocities were 4, 8, and 12 m · s -1 , which were randomly produced. The grip force required was 30% of the maximal voluntary contraction. Although the peak force (Pf) and rate of force development (RFD) increased with increasing target velocity, the value of the RFD to Pf ratio was constant across the 3 target velocities. The accuracy of both force production intensity and timing decreased at higher target velocities. Moreover, the intrapersonal variability in temporal parameters was lower in the fast target velocity condition, but constant variability in 3 target velocities was observed in force intensity parameters. These results suggest that oncoming target velocity does not intrinsically affect the ability for rapid force production. However, the oncoming target velocity affects accuracy and variability of force production intensity and timing during rapid force production.

Spin-polarized photoemission from SiGe heterostructures

Energy Technology Data Exchange (ETDEWEB)

Ferrari, A.; Bottegoni, F.; Isella, G.; Cecchi, S.; Chrastina, D.; Finazzi, M.; Ciccacci, F. [LNESS-Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

2013-12-04

We apply the principles of Optical Orientation to measure by Mott polarimetry the spin polarization of electrons photoemitted from different group-IV heterostructures. The maximum measured spin polarization, obtained from a Ge/Si{sub 0.31}Ge{sub 0.69} strained film, undoubtedly exceeds the maximum value of 50% attainable in bulk structures. The explanation we give for this result lies in the enhanced band orbital mixing between light hole and split-off valence bands as a consequence of the compressive strain experienced by the thin Ge layer.

Concept for room temperature single-spin tunneling force microscopy with atomic spatial resolution

Science.gov (United States)

Payne, Adam

A study of a force detected single-spin magnetic resonance measurement concept with atomic spatial resolution is presented. The method is based upon electrostatic force detection of spin-selection rule controlled single electron tunneling between two electrically isolated paramagnetic states. Single-spin magnetic resonance detection is possible by measuring the force detected tunneling charge noise on and off spin resonance. Simulation results of this charge noise, based upon physical models of the tunneling and spin physics, are directly compared to measured atomic force microscopy (AFM) system noise. The results show that the approach could provide single-spin measurement of electrically isolated defect states with atomic spatial resolution at room temperature.

Atomic-resolution single-spin magnetic resonance detection concept based on tunneling force microscopy

Science.gov (United States)

Payne, A.; Ambal, K.; Boehme, C.; Williams, C. C.

2015-05-01

A study of a force detected single-spin magnetic resonance measurement concept with atomic spatial resolution is presented. The method is based upon electrostatic force detection of spin-selection rule controlled single-electron tunneling between two electrically isolated paramagnetic states. Single-spin magnetic resonance detection is possible by measuring the force detected tunneling charge noise on and off spin resonance. Simulation results of this charge noise, based upon physical models of the tunneling and spin physics, are directly compared to measured atomic force microscopy system noise. The results show that the approach could provide single-spin measurement of electrically isolated qubit states with atomic spatial resolution at room temperature.

Nanoscale spin-dependent transport of electrons and holes in Si-ferromagnet structures

NARCIS (Netherlands)

Ul Haq, E.

Given the rapid development of magnetic data storage and spin-electronics into the realm of nanotechnology, the understanding of the spin-dependent electronic transport and switching behavior of magnetic structures at the nanoscale is an important issue. We have developed spin-sensitive techniques

Spin Density Matrix Elements in exclusive production of ω mesons at Hermes

Directory of Open Access Journals (Sweden)

Marianski B.

2014-03-01

Full Text Available Spin density matrix elements have been determined for exclusive ω meson production on hydrogen and deuterium targets, in the kinematic region of 1.0 < Q2 < 10.0 GeV2, 3.0 < W < 6.3 GeV and –t' < 0.2 GeV2. The data, from which SDMEs are determined, were accumulated with the HERMES forward spectrometer during the running period of 1996 to 2007 using the 27.6 GeV electron or positron beam of HERA. A sizable contribution of unnatural parity exchange amplitudes is found for exclusive ω meson production.

Puzzles of J/Ψ production off nuclei

International Nuclear Information System (INIS)

Kopeliovich, B.Z.

2011-01-01

Nuclear effects for J/Ψ production in pA collisions are controlled by the coherence and color transparency effects. Color transparency onsets when the time of formation of the charmonium wave function becomes longer than the inter-nucleon spacing. In this energy regime the effective break-up cross section for a c-barc dipole depends on energy and nuclear path length, and agrees well with data from fixed target experiments, both in magnitude and energy dependence. At higher energies of RHIC and LHC coherence in c-barc pair production leads to charm quark shadowing which is a complement to the high twist break up cross section. These two effects explain well with no adjusted parameters the magnitude and rapidity dependence of nuclear suppression of J/Ψ observed at RHIC in dAu collisions, while the contribution of leading twist gluon shadowing is found to be vanishingly small. A novel mechanism of double color filtering for c-barc dipoles makes nuclei significantly more transparent in AA compared to pA collisions. This is one of the mechanisms which make impossible a model independent 'data driven' extrapolation from pA to AA. This effect also explains the enhancement of nuclear suppression observed at forward rapidities in AA collisions at RHIC, what hardly can be related to the produced dense medium. J/Ψ is found to be a clean and sensitive tool measuring the transport coefficient characterizing the dense matter created in AA collisions. RHIC data for p T dependence of J/Ψ production in nuclear collisions are well explained with the low value of the transport coefficient q-hat 0 2 /fm.

The Disk Wind in the Rapidly Spinning Stellar-mass Black Hole 4U 1630-472 Observed with NuSTAR

Science.gov (United States)

King, Ashley L.; Walton, Dominic J.; Miller, Jon M.; Barret, Didier; Boggs, Steven E.; Christensen, Finn E.; Craig, William W.; Fabian, Andy C.; Furst, Felix; Hailey, Charles J.;

Lift-off process for deep-submicron-size junctions using supercritical CO2

International Nuclear Information System (INIS)

Fukushima, A.; Kubota, H.; Yuasa, S.; Takahachi, T.; Kadoriku, S.; Miyake, K.

2007-01-01

Deep-submicron-size (∼100-nm-size) junctions are a key element to investigate spin-torque transfer phenomena such as current induced magnetization reversal or the spin-torque diode effect. In the fabrication of submicron-size junctions using an etching method, the lift-off process after the etching process tends to be difficult as the size of junctions shrinks. In this study, we present a new lift-off process using supercritical CO 2 . In this process, the samples were immersed in solvent (mixture of N-Methyl-2-pyrrolidone and isopropanol), and pressurized by CO 2 gas. The CO 2 gas then went into supercritical phase and the solvent was removed by a continuous flow of CO 2 . We obtained considerable yield rate (success ratio in lift-off process) of more than 50% for the samples down to 100-nm-size junctions

The nuclear spin-orbit coupling

International Nuclear Information System (INIS)

Bell, J.S.; Skyrme, T.H.R.

1994-01-01

Analysis of the nucleon-nucleon scattering around 100 MeV has determined the spin-orbit coupling part of the two-body scattering matrix at that energy, and a reasonable extrapolation to lower energies is possible. This scattering amplitude has been used, in the spirit of Brueckner's nuclear model, to estimate the resultant single-body spin-orbit coupling for a single nucleon interacting with a large nucleus. This resultant potential has a radial dependence approximately proportional to r -1 d ρ /dr, and with a magnitude in good agreement with that required to explain the doublet splittings in nuclei and the polarization of nucleons scattered elastically off nuclei. (author). 14 refs, 2 figs

Spin Conference

International Nuclear Information System (INIS)

Anon.

1983-01-01

The 5th International Symposium on High Energy Spin Physics met in September at Brookhaven. The symposium has evolved to include a number of diverse specialities: theory, including parity violations and proposed quantum chromodynamics (QCD) tests with polarized beams; experiment, including the large spin effects discovered in high transverse momentum elastic scattering and hyperon production, dibaryons, and magnetic moments; acceleration and storage of polarized protons and electrons; and development of polarized sources and targets

Comparison of spin asymmetries and cross sections in. pi. sup 0 production by 200 GeV polarized antiprotons and protons

Energy Technology Data Exchange (ETDEWEB)

Adams, D L; Corcoran, M D; Cranshaw, J; Nessi-Tedaldi, F; Nessi, M; Nguyen, C; Roberts, J B; Skeens, J; White, J L [Rice Univ., Houston, TX (USA). Bonner Nuclear Labs.; Akchurin, N; Onel, Y [Iowa Univ., Iowa City (USA). Dept. of Physics and Astronomy; Belikov, N I; Derevschikov, A A; Grachov, O A; Matulenko, Yu A; Meschanin, A P; Nurushev, S B; Patalakha, D I; Rykov, V L; Solovyanov, V L; Vasiliev, A N [Institut Fiziki Vysokikh Ehnergij, Serpukhov (USSR); Bystricky, J; Lehar, F; Lesquen, A de [CEA Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France); Cossairt, J D; Read, A L [Fermi National Accelerator Lab., Batavia, IL (USA); En' yo, H; Funahashi, H; Goto, Y; Imai, K; Itow, Y; Makino, S; Masaike, A; Miyake, K; Nagamine, T; Saito, N; Yamashita, S [Kyoto Univ. (Japan). Dept. of Physics; Grosnick, D P; Hill, D A; Laghai, M; Lopiano, D; Ohashi, Y; Spinka, H; Underwood, D G; Yokosawa, A [Argonne National Lab., IL (USA); FNAL E581/704 Collaboration

1991-05-23

The single-spin asymmetry A{sub N}(anti pp) for inclusive {pi}{sup 0} production at 0.5 < p{sub t} < 2GeV/c by 200 GeV transversely-polarized antiprotons on protons has been measured at Fermilab over a wide range of x{sub F}. We observe that A{sub N}(anti pp) has the same sign, a similar x{sub F} dependence, and about half the magnitude as A{sub N}(pp) for {pi}{sup 0} production by protons. We also present the ratio of the spin-averaged sections for {pi}{sup 0} production by antiproton and by protons. (orig.).

General structure of a two-body operator for spin-(1/2) particles

International Nuclear Information System (INIS)

Ershov, S.N.

2004-01-01

A direct derivation of the operator structure for two spin-(1/2) particles is presented subject to invariance under basic symmetries and Galilean frame transformation. The partial wave decomposition for coefficient functions, valid on- and off-shell, is explicitly deduced. The momentum transfer representation and angular momentum decomposition for general spin-dependent potentials are obtained

Validity of the equivalent-photon approximation for the production of massive spin-1 particles

International Nuclear Information System (INIS)

Jayaraman, T.

1986-01-01

It is pointed out that the equivalent-photon approximation (EPA) for processes with massive spin-1 particles in the final state would have validity in a more restricted kinematic domain than for processes where it is commonly applied, viz., those with spin-1/2 or spin-0 particles in the final state. The criterion for the validity of EPA for the two-photon production of a pair of charged, massive, point-like spin-1 particles V ± , each of mass M and with a standard magnetic moment (k=1) is obtained. In a process in which one of the photons is real and the other virtual with four-momentum q, the condition for the validity of EPA is absolute value of q 2 2 , in addition to the usual condition absolute value of q 2 2 , W being the V + V - invariant mass. In a process in which both photons are virtual (with four-momenta q and q'), the condition is absolute value of q 2 absolute value of q' 2 W 4 8 , in addition to absolute value of q 2 2 , absolute value of q' 2 2 and absolute value of q 2 2 , absolute value of q' 2 2 . Even when these extra conditions permitting the use of EPA are not fulfilled, convenient approximate expressions may still be obtained assuming merely absolute value of q 2 2 and absolute value of q' 2 2 . It is also discussed how the extra conditions are altered when the vector bosons are incorporated in a spontaneously broken gauge theory. Examples of W boson production in Weinberg-Salam model are considered for which the condition absolute value of q 2 absolute value of q' 2 W 4 8 is shown to be removed. (author)

Spin-dependent transport in ferromagnet/semiconductor/ferromagnet junctions: a fully relativistic approach

International Nuclear Information System (INIS)

Popescu, Voicu; Ebert, Hubert; Papanikolaou, Nikolaos; Zeller, Rudolf; Dederichs, Peter H

2004-01-01

We present a fully relativistic generalization of the Landauer-Buettiker formalism that has been implemented within the framework of the spin-polarized relativistic screened Korringa-Kohn-Rostoker Green function method. This approach, going beyond the two-current model, supplies a more general description of the electronic transport. It is shown that the relativistic conductance can be split in terms of individual spin-diagonal and spin-off-diagonal (spin-flip) components, which allows a detailed analysis of the influence of spin-orbit-coupling-induced spin-flip processes on the spin-dependent transport. We apply our method to calculate the ballistic conductance in Fe/GaAs/Fe magnetic tunnel junctions. We find that, by removing the spin selection rules, the spin-orbit coupling strongly influences the conductance, not only qualitatively but also quantitatively, especially in the anti-parallel alignment of the magnetization in the two Fe leads

Higher spin currents in the orthogonal coset theory

Energy Technology Data Exchange (ETDEWEB)

Ahn, Changhyun [Kyungpook National University, Department of Physics, Taegu (Korea, Republic of)

2017-06-15

In the coset model (D{sub N}{sup (1)} + D{sub N}{sup (1)}, D{sub N}{sup (1)}) at levels (k{sub 1}, k{sub 2}), the higher spin 4 current that contains the quartic WZW currents contracted with a completely symmetric SO(2N) invariant d tensor of rank 4 is obtained. The three-point functions with two scalars are obtained for any finite N and k{sub 2} with k{sub 1} = 1. They are determined also in the large N 't Hooft limit. When one of the levels is the dual Coxeter number of SO(2N), k{sub 1} = 2N - 2, the higher spin (7)/(2) current, which contains the septic adjoint fermions contracted with the above d tensor and the triple product of structure constants, is obtained from the operator product expansion (OPE) between the spin (3)/(2) current living in the N = 1 superconformal algebra and the above higher spin 4 current. The OPEs between the higher spin (7)/(2), 4 currents are described. For k{sub 1} = k{sub 2} = 2N - 2 where both levels are equal to the dual Coxeter number of SO(2N), the higher spin 3 current of U(1) charge (4)/(3), which contains the six products of spin (1)/(2) (two) adjoint fermions contracted with the product of the d tensor and two structure constants, is obtained. The corresponding N = 2 higher spin multiplet is determined by calculating the remaining higher spin (7)/(2), (7)/(2), 4 currents with the help of two spin (3)/(2) currents in the N = 2 superconformal algebra. The other N = 2 higher spin multiplet, whose U(1) charge is opposite to the one of the above N = 2 higher spin multiplet, is obtained. The OPE between these two N = 2 higher spin multiplets is also discussed. (orig.)

Baryon production in e+e- annihilation

International Nuclear Information System (INIS)

Saxon, D.H.

1988-11-01

The phenomenology of baryon production in high energy e + e - annihilation is described. Much can be understood in terms of mass effects. Comparisons with the rates for different flavours and spins, with momentum and transverse momentum spectra and with particle correlations are used to confront models. Diquark models give good descriptions, except for the on/off Υ(1s) rates. Areas for experimental and theoretical development are indicated. (author)

Characteristics of products generated by selective sintering and stereolithography rapid prototyping processes

Science.gov (United States)

Cariapa, Vikram

1993-01-01

The trend in the modern global economy towards free market policies has motivated companies to use rapid prototyping technologies to not only reduce product development cycle time but also to maintain their competitive edge. A rapid prototyping technology is one which combines computer aided design with computer controlled tracking of focussed high energy source (eg. lasers, heat) on modern ceramic powders, metallic powders, plastics or photosensitive liquid resins in order to produce prototypes or models. At present, except for the process of shape melting, most rapid prototyping processes generate products that are only dimensionally similar to those of the desired end product. There is an urgent need, therefore, to enhance the understanding of the characteristics of these processes in order to realize their potential for production. Currently, the commercial market is dominated by four rapid prototyping processes, namely selective laser sintering, stereolithography, fused deposition modelling and laminated object manufacturing. This phase of the research has focussed on the selective laser sintering and stereolithography rapid prototyping processes. A theoretical model for these processes is under development. Different rapid prototyping sites supplied test specimens (based on ASTM 638-84, Type I) that have been measured and tested to provide a data base on surface finish, dimensional variation and ultimate tensile strength. Further plans call for developing and verifying the theoretical models by carefully designed experiments. This will be a joint effort between NASA and other prototyping centers to generate a larger database, thus encouraging more widespread usage by product designers.

Voltage switching technique for detecting nuclear spin polarization in a quantum dot

International Nuclear Information System (INIS)

Takahashi, Ryo; Kono, Kimitoshi; Tarucha, Seigo; Ono, Keiji

2010-01-01

We have introduced a source-drain voltage switching technique for studying nuclear spins in a vertical double quantum dot. Switching the source-drain voltage between the spin-blockade state and the zero-bias Coulomb blockade state can tune the energy difference between the spin singlet and triplet, and effectively turn on/off the hyperfine interaction. Since the change in the nuclear spin state affects the source-drain current, nuclear spin properties can only be detected by transport measurement. Using this technique, we have succeeded in measuring the timescale of nuclear spin depolarization. Furthermore, combining this technique and an RF ac magnetic field, we successfully detected continuous-wave NMR signals of 75 As, 69 Ga, and 71 Ga, which are contained in a quantum dot. (author)

On the spin-dependent sensitivity of XENON100

Energy Technology Data Exchange (ETDEWEB)

Garny, Mathias [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Ibarra, Alejandro; Pato, Miguel; Vogl, Stefan [Technische Univ. Muenchen, Garching (Germany). Physik-Department

2012-11-15

The latest XENON100 data severely constrains dark matter elastic scattering off nuclei, leading to impressive upper limits on the spin-independent cross-section. The main goal of this paper is to stress that the same data set has also an excellent spin-dependent sensitivity, which is of utmost importance in probing dark matter models. We show in particular that the constraints set by XENON100 on the spin-dependent neutron cross-section are by far the best at present, whereas the corresponding spin-dependent proton limits lag behind other direct detection results. The effect of nuclear uncertainties on the structure functions of xenon isotopes is analysed in detail and found to lessen the robustness of the constraints, especially for spin-dependent proton couplings. Notwith-standing, the spin-dependent neutron prospects for XENON1T and DARWIN are very encouraging. We apply our constraints to well-motivated dark matter models and demonstrate that in both mass-degenerate scenarios and the minimal supersymmetric standard model the spin-dependent neutron limits can actually override the spin-independent limits. This opens the possibility of probing additional unexplored regions of the dark matter parameter space with the next generation of ton-scale direct detection experiments.

On the spin-dependent sensitivity of XENON100

International Nuclear Information System (INIS)

Garny, Mathias; Ibarra, Alejandro; Pato, Miguel; Vogl, Stefan

2012-11-01

The latest XENON100 data severely constrains dark matter elastic scattering off nuclei, leading to impressive upper limits on the spin-independent cross-section. The main goal of this paper is to stress that the same data set has also an excellent spin-dependent sensitivity, which is of utmost importance in probing dark matter models. We show in particular that the constraints set by XENON100 on the spin-dependent neutron cross-section are by far the best at present, whereas the corresponding spin-dependent proton limits lag behind other direct detection results. The effect of nuclear uncertainties on the structure functions of xenon isotopes is analysed in detail and found to lessen the robustness of the constraints, especially for spin-dependent proton couplings. Notwith-standing, the spin-dependent neutron prospects for XENON1T and DARWIN are very encouraging. We apply our constraints to well-motivated dark matter models and demonstrate that in both mass-degenerate scenarios and the minimal supersymmetric standard model the spin-dependent neutron limits can actually override the spin-independent limits. This opens the possibility of probing additional unexplored regions of the dark matter parameter space with the next generation of ton-scale direct detection experiments.

Recurring off-types in lettuce: Their significance in plant breeding and seed production.

Science.gov (United States)

Maxon Smith, J W

1977-03-01

The lettuce cv. Valentine regularly produces non-heading off-type plants at the relatively high frequency of 4 × 10(-3). They result from mutation to the dominant condition. A similar propensity has been reported twice before in lettuce; it is highly heritable.The propensity to produce off-types was not present in the parents of Valentine so it must have arisen during the pedigree breeding programme. Closely related cultivars do not carry the character but it was subsequently transmitted to Dandie a new cultivar of which Valentine was one of the parents. Allelism tests to relate Valentine off-types to those in crisphead cultivars were not successful.The elimination of off-types in breeding programmes is discussed. Contrary to the findings in day-neutral crisphead cultivars, mutant phenotypes in long-day butterhead cultivars have no selective advantage for seed production. Consequently, strict roguing ensures adequate varietal stability.

Spin polarisation with electron Bessel beams

Energy Technology Data Exchange (ETDEWEB)

Schattschneider, P., E-mail: schattschneider@ifp.tuwien.ac.at [Institut für Festkörperphysik, Technische Universität Wien, A-1040 Wien (Austria); USTEM, Technische Universität Wien, A-1040 Wien (Austria); Grillo, V. [CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/a, I-41125 Modena (Italy); CNR-IMEM, Parco delle Scienze 37a, I-43100 Parma (Italy); Aubry, D. [Centrale Supelec, MSSMast CNRS 8579, F-92295 Châtenay-Malabry (France)

2017-05-15

The theoretical possibility to use an electron microscope as a spin polarizer is studied. It turns out that a Bessel beam passing a standard magnetic objective lens is intrinsically spin polarized when post-selected on-axis. In the limit of infinitely small detectors, the spin polarisation tends to 100 %. Increasing the detector size, the polarisation decreases rapidly, dropping below 10{sup −4} for standard settings of medium voltage microscopes. For extremely low voltages, the Figure of Merit increases by two orders of magnitude, approaching that of existing Mott detectors. Our findings may lead to new desings of spin filters, an attractive option in view of its inherent combination with the electron microscope, especially at low voltage. - Highlights: • TEM round magnetic lenses can act as spin polarizers when a Bessel beam is sent through. • This is found on theoretical grounds and demonstrated numerically for a few cases. • The effect is small, but can reach a Figure of Merit similar to existing Mott detectors. • This opens the possibility to construct nanometer-sized spin filters or detectors.

Two-stage maintenance of a production system with exponentially distributed on and off-periods

NARCIS (Netherlands)

van Dijkhuizen, G.C.; van Harten, Aart

1998-01-01

We consider an on–off production system which is subject to failure during on-periods. In case of a failure, the production system is maintained correctively. In addition, preventive maintenance is carried out to prevent failures. The costs of both preventive and corrective maintenance are modelled

Development and test of model apparatus of non-contact spin processor for photo mask production applying radial-type superconducting magnetic bearing

International Nuclear Information System (INIS)

Saito, Kimiyo; Fukui, Satoshi; Maezawa, Masaru; Ogawa, Jun; Oka, Tetsuo; Sato, Takao

2013-01-01

Highlights: ► We develop test spinner for non-contact spinning process in photo mask production. ► This test spinner shows improved spinning ability compared with our previous one. ► Large vertical movement of turn table still occurs during acceleration. ► Method to control vertical movement of turn table should be developed in next step. -- Abstract: In semiconductor devices, miniaturization of circuit patterning on wafers is required for higher integrations of circuit elements. Therefore, very high tolerance and quality are also required for patterning of microstructures of photo masks. The deposition of particulate dusts generated from mechanical bearings of the spin processor in the patterns of the photo mask is one of main causes of the deterioration of pattern preciseness. In our R and D, application of magnetic bearing utilizing bulk high temperature superconductors to the spin processors has been proposed. In this study, we develop a test spinner for the non-contact spinning process in the photo mask production system. The rotation test by using this test spinner shows that this test spinner accomplishes the improvement of the spinning ability compared with the test spinner developed in our previous study. This paper describes the rotation test results of the new test spinner applying the magnetic bearing with bulk high temperature superconductors

Synthetic Spider Silk Production on a Laboratory Scale

Science.gov (United States)

Hsia, Yang; Gnesa, Eric; Pacheco, Ryan; Kohler, Kristin; Jeffery, Felicia; Vierra, Craig

2012-01-01

As society progresses and resources become scarcer, it is becoming increasingly important to cultivate new technologies that engineer next generation biomaterials with high performance properties. The development of these new structural materials must be rapid, cost-efficient and involve processing methodologies and products that are environmentally friendly and sustainable. Spiders spin a multitude of different fiber types with diverse mechanical properties, offering a rich source of next generation engineering materials for biomimicry that rival the best manmade and natural materials. Since the collection of large quantities of natural spider silk is impractical, synthetic silk production has the ability to provide scientists with access to an unlimited supply of threads. Therefore, if the spinning process can be streamlined and perfected, artificial spider fibers have the potential use for a broad range of applications ranging from body armor, surgical sutures, ropes and cables, tires, strings for musical instruments, and composites for aviation and aerospace technology. In order to advance the synthetic silk production process and to yield fibers that display low variance in their material properties from spin to spin, we developed a wet-spinning protocol that integrates expression of recombinant spider silk proteins in bacteria, purification and concentration of the proteins, followed by fiber extrusion and a mechanical post-spin treatment. This is the first visual representation that reveals a step-by-step process to spin and analyze artificial silk fibers on a laboratory scale. It also provides details to minimize the introduction of variability among fibers spun from the same spinning dope. Collectively, these methods will propel the process of artificial silk production, leading to higher quality fibers that surpass natural spider silks. PMID:22847722

The Spin Torque Lego - from spin torque nano-devices to advanced computing architectures

Science.gov (United States)

Grollier, Julie

2013-03-01

Spin transfer torque (STT), predicted in 1996, and first observed around 2000, brought spintronic devices to the realm of active elements. A whole class of new devices, based on the combined effects of STT for writing and Giant Magneto-Resistance or Tunnel Magneto-Resistance for reading has emerged. The second generation of MRAMs, based on spin torque writing : the STT-RAM, is under industrial development and should be out on the market in three years. But spin torque devices are not limited to binary memories. We will rapidly present how the spin torque effect also allows to implement non-linear nano-oscillators, spin-wave emitters, controlled stochastic devices and microwave nano-detectors. What is extremely interesting is that all these functionalities can be obtained using the same materials, the exact same stack, simply by changing the device geometry and its bias conditions. So these different devices can be seen as Lego bricks, each brick with its own functionality. During this talk, I will show how spin torque can be engineered to build new bricks, such as the Spintronic Memristor, an artificial magnetic nano-synapse. I will then give hints on how to assemble these bricks in order to build novel types of computing architectures, with a special focus on neuromorphic circuits. Financial support by the European Research Council Starting Grant NanoBrain (ERC 2010 Stg 259068) is acknowledged.

Spin as a probe of hadron structure

International Nuclear Information System (INIS)

Ali, R.

1995-01-01

In this thesis, hadron structure was explored by studying three problems. In each case some underlying hard process, or a characteristic hard momentum, yielded important physical information such as structure and fragmentation functions describing hadrons. This provided a test of QCD predictions. In the first problem, spin dependent quark structure functions were estimated for nuclei. The multipole L=2 structure function, measurable in deeply inelastic scattering of unpolarized leptons off a polarized J > 1 nuclear target, is a good indicator of exotic quark gluon components in the nucleus. I estimated this structure function for two different classes of nuclei light nuclei describable in an independent particle model approach, as well as for heavy nuclei described by slowly rotating collective variables. In the second problem, spin dependent gluonic structure functions in a transversely polarized proton were identified and the classification according to twist was discussed. I found that there were two twist three transverse spin gluonic structure functions, called herein H1(x,Q2) and H2(x,Q2). Cross section formulae were calculated for a variety of polarization states, assuming a simple effective interaction for X2 production from gluon fusion. In the third, and final problem, the emphasis shifted from spin dependent structure functions of polarised hadrons to the formulation of an effective, low energy, field theory of s wave quarkonia, constituent heavy quarks, and gluons. and radiative transitions were shown to be easily recovered. The light-cone gluon momentum distribution at very small x was calculated and shown to be uniquely determined by the non relativistic wave function. I found that the emission of low momentum gluons made this process quite sensitive to assumptions about the binding energy of heavy quarks in quarkonia. This gauge invariant theory is extend able to p-wave quarkonia where the non locality of the meson state is enhanced by the

Flight test of a spin parachute for use with a Super Arcas sounding rocket

Science.gov (United States)

Silbert, M. N.

1975-01-01

The development and flight testing of a specially configured 16.6 ft Disc Band Gap (DBG) Spin Parachute is discussed. The parachute is integrated with a modified Super Arcas launch vehicle. Total payload weight was 17.6 lbs including the Spin Parachute and a scientific payload, and lift-off weight was 100.3 lbs. The Super Arcas vehicle was despun from 18.4 cps. After payload separation at 244,170 ft the Spin Parachute and its payload attained a maximum spin rate of 2.4 cps. Total suspended weight of the Spin Parachute and its payload was 14.64 lbs.

Investigation of spin correlations in top-pair production with the CMS detector at the LHC

International Nuclear Information System (INIS)

Davids, Martina

2011-01-01

In spring 2010 the Large Hadron Collider (LHC) started its operation with a center-of-mass energy of 7 TeV, that will be increased up to 14 TeV in the following years. Considering a medium energy of √(s)=10 TeV and a luminosity of L=10 33 cm -2 s -1 some million top quarks are produced per year. This offers the opportunity to investigate spin-correlations between the top quarks from pair production. As the spinconfiguration of the top-quark pair depends on the production mechanism, a measurement of such effects is a unique tool to study the contributions of the production processes and spin effects. This allows to test the Standard Model. This thesis investigates dileptonic top-pair decays at the Compact Muon Solenoid based on simulated events. A quantitative measure of spin correlations is the asymmetry A, that manifests itself in the angular distribution of the two leptons. A full kinematic reconstruction of the top pair is necessary to determine this distribution. The MC generators Pythia, MC rate at NLO, and TopReX are tested with respect to their treatment of spin-correlations. Pythia is used to generate uncorrelated samples. MC rate at NLO reproduces the Standard Model prediction. These samples are used to determine the sensitivity of the present analysis. Due to an incorrect implementation of the helicity states, TopReX is not usable. A full event selection and reconstruction are adapted. The reconstructed angular distribution shows a significant distortion. A template method is implemented to determine the asymmetry. Here, the angular distribution is decomposed into a flat, a completely asymmetric, and a background part, that are fitted by a binned χ 2 approach to toy-data. An ensemble study is performed to estimate the statistical uncertainty. As the main systematic uncertainties, generator effects, the jet energy scale and uncertainties in the cross sections or selection efficiency are investigated. Considering an integrated luminosity of L int =1 fb

Investigation of spin correlations in top-pair production with the CMS detector at the LHC

Energy Technology Data Exchange (ETDEWEB)

Davids, Martina

2011-02-25

In spring 2010 the Large Hadron Collider (LHC) started its operation with a center-of-mass energy of 7 TeV, that will be increased up to 14 TeV in the following years. Considering a medium energy of {radical}(s)=10 TeV and a luminosity of L=10{sup 33} cm{sup -2}s{sup -1} some million top quarks are produced per year. This offers the opportunity to investigate spin-correlations between the top quarks from pair production. As the spinconfiguration of the top-quark pair depends on the production mechanism, a measurement of such effects is a unique tool to study the contributions of the production processes and spin effects. This allows to test the Standard Model. This thesis investigates dileptonic top-pair decays at the Compact Muon Solenoid based on simulated events. A quantitative measure of spin correlations is the asymmetry A, that manifests itself in the angular distribution of the two leptons. A full kinematic reconstruction of the top pair is necessary to determine this distribution. The MC generators Pythia, MC rate at NLO, and TopReX are tested with respect to their treatment of spin-correlations. Pythia is used to generate uncorrelated samples. MC rate at NLO reproduces the Standard Model prediction. These samples are used to determine the sensitivity of the present analysis. Due to an incorrect implementation of the helicity states, TopReX is not usable. A full event selection and reconstruction are adapted. The reconstructed angular distribution shows a significant distortion. A template method is implemented to determine the asymmetry. Here, the angular distribution is decomposed into a flat, a completely asymmetric, and a background part, that are fitted by a binned {chi}{sup 2} approach to toy-data. An ensemble study is performed to estimate the statistical uncertainty. As the main systematic uncertainties, generator effects, the jet energy scale and uncertainties in the cross sections or selection efficiency are investigated. Considering an integrated

Thoracic sonography for pneumothorax: The clinical evaluation of an operational space medicine spin-off

Science.gov (United States)

Kirkpatrick, Andrew W.; Nicolaou, Savvas; Rowan, Kevin; Liu, David; Cunningham, Johan; Sargsyan, Ashot E.; Hamilton, Douglas; Dulchavsky, Scott A.

2005-05-01

The recent interest in the use of ultrasound (US) to detect pneumothoraces after acute trauma in North America was initially driven by an operational space medicine concern. Astronauts aboard the International Space Station (ISS) are at risk for pneumothoraces, and US is the only potential medical imaging available. Pneumothoraces are common following trauma, and are a preventable cause of death, as most are treatable with relatively simple interventions. While pneumothoraces are optimally diagnosed clinically, they are more often inapparent even on supine chest radiographs (CXR) with recent series reporting a greater than 50% rate of occult pneumothoraces. In the course of basic scientific investigations in a conventional and parabolic flight laboratory, investigators familiarized themselves with the sonographic features of both pneumothoraces and normal pulmonary ventilation. By examining the visceral-parietal pleural interface (VPPI) with US, investigators became confident in diagnosing pneumothoraces. This knowledge was subsequently translated into practice at an American and a Canadian trauma center. The sonographic examination was found to be more accurate and sensitive than CXR (US 96% and 100% versus US 74% and 36%) in specific circumstances. Initial studies have also suggested that detecting the US features of pleural pulmonary ventilation in the left lung field may offer the ability to exclude serious endotracheal tube malpositions such as right mainstem and esophageal intubations. Applied thoracic US is an example of a clinically useful space medicine spin-off that is improving health care on earth.

Electron Spin Optical Orientation in Charged Quantum Dots

Science.gov (United States)

Shabaev, A.; Gershoni, D.; Korenev, V. L.

2005-03-01

We present a theory of nonresonant optical orientation of electron spins localized in quantum dots. This theory explains the negative circularly polarized photoluminescence of singlet trions localized in quantum dots previously observed in experiments where trion polarization changed to negative with time and where the degree of the negative polarization increased with intensity of pumping light. We have shown that this effect can be explained by the accumulation of dark excitons that occurs due to the spin blocking of the singlet trion formation - the major mechanism of dark exciton recombination. The accumulation of dark excitons results from a lack of electrons with a spin matching the exciton polarization. The electron spin lifetime is shortened by a transverse magnetic field or a temperature increase. This takes the block off the dark exciton recombination and restores the positive degree of trion polarization. The presented theory gives good agreement with experimental data.

Spin-wave resonances and surface spin pinning in Ga1-xMnxAs thin films

Science.gov (United States)

Bihler, C.; Schoch, W.; Limmer, W.; Goennenwein, S. T. B.; Brandt, M. S.

2009-01-01

We investigate the dependence of the spin-wave resonance (SWR) spectra of Ga0.95Mn0.05As thin films on the sample treatment. We find that for the external magnetic field perpendicular to the film plane, the SWR spectrum of the as-grown thin films and the changes upon etching and short-term hydrogenation can be quantitatively explained via a linear gradient in the uniaxial magnetic anisotropy field in growth direction. The model also qualitatively explains the SWR spectra observed for the in-plane easy-axis orientation of the external magnetic field. Furthermore, we observe a change in the effective surface spin pinning of the partially hydrogenated sample, which results from the tail in the hydrogen-diffusion profile. The latter leads to a rapidly changing hole concentration/magnetic anisotropy profile acting as a barrier for the spin-wave excitations. Therefore, short-term hydrogenation constitutes a simple method to efficiently manipulate the surface spin pinning.

SD-CAS: Spin Dynamics by Computer Algebra System.

Science.gov (United States)

Filip, Xenia; Filip, Claudiu

2010-11-01

A computer algebra tool for describing the Liouville-space quantum evolution of nuclear 1/2-spins is introduced and implemented within a computational framework named Spin Dynamics by Computer Algebra System (SD-CAS). A distinctive feature compared with numerical and previous computer algebra approaches to solving spin dynamics problems results from the fact that no matrix representation for spin operators is used in SD-CAS, which determines a full symbolic character to the performed computations. Spin correlations are stored in SD-CAS as four-entry nested lists of which size increases linearly with the number of spins into the system and are easily mapped into analytical expressions in terms of spin operator products. For the so defined SD-CAS spin correlations a set of specialized functions and procedures is introduced that are essential for implementing basic spin algebra operations, such as the spin operator products, commutators, and scalar products. They provide results in an abstract algebraic form: specific procedures to quantitatively evaluate such symbolic expressions with respect to the involved spin interaction parameters and experimental conditions are also discussed. Although the main focus in the present work is on laying the foundation for spin dynamics symbolic computation in NMR based on a non-matrix formalism, practical aspects are also considered throughout the theoretical development process. In particular, specific SD-CAS routines have been implemented using the YACAS computer algebra package (http://yacas.sourceforge.net), and their functionality was demonstrated on a few illustrative examples. Copyright © 2010 Elsevier Inc. All rights reserved.

Organic Spin-Valves and Beyond: Spin Injection and Transport in Organic Semiconductors and the Effect of Interfacial Engineering.

Science.gov (United States)

Jang, Hyuk-Jae; Richter, Curt A

2017-01-01

Since the first observation of the spin-valve effect through organic semiconductors, efforts to realize novel spintronic technologies based on organic semiconductors have been rapidly growing. However, a complete understanding of spin-polarized carrier injection and transport in organic semiconductors is still lacking and under debate. For example, there is still no clear understanding of major spin-flip mechanisms in organic semiconductors and the role of hybrid metal-organic interfaces in spin injection. Recent findings suggest that organic single crystals can provide spin-transport media with much less structural disorder relative to organic thin films, thus reducing momentum scattering. Additionally, modification of the band energetics, morphology, and even spin magnetic moment at the metal-organic interface by interface engineering can greatly impact the efficiency of spin-polarized carrier injection. Here, progress on efficient spin-polarized carrier injection into organic semiconductors from ferromagnetic metals by using various interface engineering techniques is presented, such as inserting a metallic interlayer, a molecular self-assembled monolayer (SAM), and a ballistic carrier emitter. In addition, efforts to realize long spin transport in single-crystalline organic semiconductors are discussed. The focus here is on understanding and maximizing spin-polarized carrier injection and transport in organic semiconductors and insight is provided for the realization of emerging organic spintronics technologies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Excitonic magnet in external field: Complex order parameter and spin currents

Science.gov (United States)

Geffroy, D.; Hariki, A.; Kuneš, J.

2018-04-01

We investigate spin-triplet exciton condensation in the two-orbital Hubbard model close to half-filling by means of dynamical mean-field theory. Employing an impurity solver that handles complex off-diagonal hybridization functions, we study the behavior of excitonic condensate in stoichiometric and doped systems subject to external magnetic field. We find a general tendency of the triplet order parameter to lie perpendicular with the applied field and identify exceptions from this rule. For solutions exhibiting k -odd spin textures, we discuss the Bloch theorem, which, in the absence of spin-orbit coupling, forbids the appearance of spontaneous net spin current. We demonstrate that the Bloch theorem is not obeyed by the dynamical mean-field theory.

Centrifugal Spinning and Its Energy Storage Applications

Science.gov (United States)

Yao, Lu

Lithium-ion batteries (LIBs) and supercapacitors are important electrochemical energy storage systems. LIBs have high specific energy density, long cycle life, good thermal stability, low self-discharge, and no memory effect. However, the low abundance of Li in the Earth's crust and the rising cost of LIBs urge the attempts to develop alternative energy storage systems. Recently, sodium-ion batteries (SIBs) have become an attractive alternative to LIBs due to the high abundance and low cost of Na. Although the specific capacity and energy density of SIBs are not as high as LIBs, SIBs can still be promising power sources for certain applications such as large-scale, stationary grids. Supercapacitors are another important class of energy storage devices. Electric double-layer capacitors (EDLCs) are one important type of supercapacitors and they exhibit high power density, long cycle life, excellent rate capability and environmental friendliness. The potential applications of supercapacitors include memory protection in electronic circuitry, consumer portable electronic devices, and electrical hybrid vehicles. The electrochemical performance of SIBs and EDLCs is largely dependent on the electrode materials. Therefore, development of superior electrodes is the key to achieve highperformance alternative energy storage systems. Recently, one-dimensional nano-/micro-fiber based electrodes have become promising candidates in energy storage because they possess a variety of desirable properties including large specific surface area, well-guided ionic/electronic transport, and good electrode-electrolyte contact, which contribute to enhanced electrochemical performance. Currently, most nano-/micro-fiber based electrodes are prepared via electrospinning method. However, the low production rate of this approach hinders its practical application in the production of fibrous electrodes. Thus, it is significantly important to employ a rapid, low-cost and scalable nano

Entropy Production and Equilibrium Conditions of General-Covariant Spin Systems

Directory of Open Access Journals (Sweden)

Wolfgang Muschik

2015-12-01

Full Text Available In generalizing the special-relativistic one-component version of Eckart’s continuum thermodynamics to general-relativistic space-times with Riemannian or post-Riemannian geometry as presented by Schouten (Schouten, J.A. Ricci-Calculus, 1954 and Blagojevic (Blagojevic, M. Gauge Theories of Gravitation, 2013 we consider the entropy production and other thermodynamical quantities, such as the entropy flux and the Gibbs fundamental equation. We discuss equilibrium conditions in gravitational theories, which are based on such geometries. In particular, thermodynamic implications of the non-symmetry of the energy-momentum tensor and the related spin balance equations are investigated, also for the special case of general relativity.

The non-linear coupled spin 2-spin 3 Cotton equation in three dimensions

Energy Technology Data Exchange (ETDEWEB)

Linander, Hampus; Nilsson, Bengt E.W. [Department of Physics, Theoretical PhysicsChalmers University of Technology, S-412 96 Göteborg (Sweden)

2016-07-05

In the context of three-dimensional conformal higher spin theory we derive, in the frame field formulation, the full non-linear spin 3 Cotton equation coupled to spin 2. This is done by solving the corresponding Chern-Simons gauge theory system of equations, that is, using F=0 to eliminate all auxiliary fields and thus expressing the Cotton equation in terms of just the spin 3 frame field and spin 2 covariant derivatives and tensors (Schouten). In this derivation we neglect the spin 4 and higher spin sectors and approximate the star product commutator by a Poisson bracket. The resulting spin 3 Cotton equation is complicated but can be related to linearized versions in the metric formulation obtained previously by other authors. The expected symmetry (spin 3 “translation”, “Lorentz” and “dilatation”) properties are verified for Cotton and other relevant tensors but some perhaps unexpected features emerge in the process, in particular in relation to the non-linear equations. We discuss the structure of this non-linear spin 3 Cotton equation but its explicit form is only presented here, in an exact but not completely refined version, in appended files obtained by computer algebra methods. Both the frame field and metric formulations are provided.

Damping-off in forest nurseries

Science.gov (United States)

Carl Hartley

1921-01-01

Damping-off is the commonest English name for a symptomatic group of diseases affecting great numbers of plant species of widely separated phylogenetic groups. It is commonly used for any disease which results in the rapid decay of young succulent seedlings or soft cuttings. Young shoots from underground rootstocks may also be damped-off before they break through the...

Centennial-scale variations in diatom productivity off Peru over the last 3000 years

Science.gov (United States)

Fleury, Sophie; Crosta, Xavier; Schneider, Ralph; Blanz, Thomas; Ther, Olivier; Martinez, Philippe; Kim, Jung-Hyun

2016-04-01

The Peruvian coastal upwelling is one of the most productive systems in the global ocean, with important impacts on the carbon cycle. Primary productivity there displays strong variations at the inter-annual to decadal timescales. However, down-core investigations rarely reach sufficient temporal resolution to assess the response of productivity to climatic variations at these timescales beyond the instrumental and historical periods. We here analyzed diatom assemblages, sea-surface temperatures, nitrogen and organic carbon contents on a laminated sediment core from the Peruvian continental shelf to trace variations in regional productivity over the last 3000 years. Our record provides evidence for different climatic and oceanic conditions with more humid and less productive conditions older than 2500 Cal years BP and drier and more productive conditions younger than 2500 Cal years BP. The last 2500 years also present much stronger centennial-scale variability with the occurrence of six intervals with higher total diatom abundances and stronger percentages in upwelling-related diatom species, representative of intensified productivity, congruent to lower percentages in benthic diatoms, indicative of reduced rainfall. These six periods were synchronous to intervals of enhanced Walker circulation, suggesting a strong imprint of the Pacific zonal circulation on productivity variations off Peru. Our record also demonstrates that SSTs did not vary in phase with productivity, arguing against the idea of regional SSTs controlled by the upwelling intensity, but were rather in agreement to SST records off southern Chile, suggesting that Peruvian SSTs variations were largely controlled by oceanic currents at southern high latitudes.

Neutron spin precession in samples of polarised nuclei and neutron spin phase imaging

Energy Technology Data Exchange (ETDEWEB)

Piegsa, Florian Michael

2009-07-09

neutron with ferromagnetic samples and magnetic fields. For the first time, quantitative imaging of such samples could be performed using a dedicated compact Ramsey apparatus. First results of this spin-off project as well as the principle idea of the imaging technique are presented. (orig.)

Neutron spin precession in samples of polarised nuclei and neutron spin phase imaging

International Nuclear Information System (INIS)

Piegsa, Florian Michael

2009-01-01

. For the first time, quantitative imaging of such samples could be performed using a dedicated compact Ramsey apparatus. First results of this spin-off project as well as the principle idea of the imaging technique are presented. (orig.)

Evolution of nuclear collectivity at high spins and temperatures

International Nuclear Information System (INIS)

Baktash, C.

1989-01-01

In the past few years, we have utilized the Spin Spectrometer and a variety of complementary probes (continuum γrays, proton-γ coincidence spectroscopy and γ decay of GDR) to study the nuclear response to the DIFFERENTIAL effects of increasing spin and temperature for constant values of excitation energy or spin, respectively. In this paper we shall describe two of the experiments that trace the properties of rapidly-rotating nuclei at small to moderate excitation energies. 22 refs., 7 figs

Photo-modulation of the spin Hall conductivity of mono-layer transition metal dichalcogenides

Energy Technology Data Exchange (ETDEWEB)

Sengupta, Parijat; Bellotti, Enrico [Department of Electrical and Computer Engineering, Boston University, Boston, MA 02215 (United States)

2016-05-23

We report on a possible optical tuning of the spin Hall conductivity in mono-layer transition metal dichalcogenides. Light beams of frequencies much higher than the energy scale of the system (the off-resonant condition) do not excite electrons but rearrange the band structure. The rearrangement is quantitatively established using the Floquet formalism. For such a system of mono-layer transition metal dichalcogenides, the spin Hall conductivity (calculated with the Kubo expression in presence of disorder) exhibits a drop at higher frequencies and lower intensities. Finally, we compare the spin Hall conductivity of the higher spin-orbit coupled WSe{sub 2} to MoS{sub 2}; the spin Hall conductivity of WSe{sub 2} was found to be larger.

More spinoff from spin

International Nuclear Information System (INIS)

Masaike, Akira

1993-01-01

Despite playing a major role in today's Standard Model, spin - the intrinsic angular momentum carried by particles - is sometimes dismissed as an inessential complication. However several major spin questions with important implications for the Standard Model remain unanswered, and recent results and new technological developments made the 10th International Symposium on High Energy Spin Physics, held in Nagoya, Japan, in November, highly topical. The symposium covered a wide range of physics, reflecting the diversity of spin effects, however four main themes were - the spin content of the nucleon, tests of symmetries and physics beyond standard models, intermediate energy physics, and spin technologies. Opening the meeting, T. Kinoshita reviewed the status of measurements of the anomalous magnetic moment (g-2) of the electron and the muon. The forthcoming experiment at Brookhaven (September 1991, page 23) will probe beyond the energy ranges open to existing electronpositron colliders. For example muon substructure will be opened up to 5 TeV and Ws to 2 TeV. R.L. Jaffe classified quark-parton distributions in terms of their spin dependence, pointing out their leftright attributes, and emphasized the importance of measuring transverse spin distributions through lepton pair production

Spin-orbit torques in magnetic bilayers

Science.gov (United States)

Haney, Paul

2015-03-01

Spintronics aims to utilize the coupling between charge transport and magnetic dynamics to develop improved and novel memory and logic devices. Future progress in spintronics may be enabled by exploiting the spin-orbit coupling present at the interface between thin film ferromagnets and heavy metals. In these systems, applying an in-plane electrical current can induce magnetic dynamics in single domain ferromagnets, or can induce rapid motion of domain wall magnetic textures. There are multiple effects responsible for these dynamics. They include spin-orbit torques and a chiral exchange interaction (the Dzyaloshinskii-Moriya interaction) in the ferromagnet. Both effects arise from the combination of ferromagnetism and spin-orbit coupling present at the interface. There is additionally a torque from the spin current flux impinging on the ferromagnet, arising from the spin hall effect in the heavy metal. Using a combination of approaches, from drift-diffusion to Boltzmann transport to first principles methods, we explore the relative contributions to the dynamics from these different effects. We additionally propose that the transverse spin current is locally enhanced over its bulk value in the vicinity of an interface which is oriented normal to the charge current direction.

Positivity of spin foam amplitudes

International Nuclear Information System (INIS)

Baez, John C; Christensen, J Daniel

2002-01-01

The amplitude for a spin foam in the Barrett-Crane model of Riemannian quantum gravity is given as a product over its vertices, edges and faces, with one factor of the Riemannian 10j symbols appearing for each vertex, and simpler factors for the edges and faces. We prove that these amplitudes are always nonnegative for closed spin foams. As a corollary, all open spin foams going between a fixed pair of spin networks have real amplitudes of the same sign. This means one can use the Metropolis algorithm to compute expectation values of observables in the Riemannian Barrett-Crane model, as in statistical mechanics, even though this theory is based on a real-time (e iS ) rather than imaginary-time e -S path integral. Our proof uses the fact that when the Riemannian 10j symbols are nonzero, their sign is positive or negative depending on whether the sum of the ten spins is an integer or half-integer. For the product of 10j symbols appearing in the amplitude for a closed spin foam, these signs cancel. We conclude with some numerical evidence suggesting that the Lorentzian 10j symbols are always nonnegative, which would imply similar results for the Lorentzian Barrett-Crane model

Heavy Flavour Production as Probe of Gluon Sivers Function

International Nuclear Information System (INIS)

Godbole, Rohini M.; Kaushik, Abhiram; Misra, Anuradha; Rawoot, Vaibhav; Sonawane, Bipin

2017-01-01

Heavy flavour production like J/ψ and D-meson production in scattering of electrons/unpolarized protons off polarized proton target offer promising probes to investigate gluon Sivers function. In this talk, I will summarize our recent work on transverse single spin asymmetry in J/ψ-production and D-meson production in pp↑ scattering using a generalized parton model approach. We compare predictions obtained using different models of gluon Sivers function within this approach and then, taking into account the transverse momentum dependent evolution of the unpolarized parton distribution functions and gluon Sivers function, we study the effect of evolution on asymmetry. (author)

Production of entropy on simplified dynamics in spin glass systems

CERN Document Server

Saakyan, D B

2001-01-01

In models of spin glasses one eliminates condition of extreme based on one of the order parameters. On the basis of the available expression for static sum one derived the effective hamiltonian for parameter and the appropriate energy. Relaxation of the system is studied as energy exchange between the degree of freedom related to the order slow parameter and with the rest of the system. At that level one may indicate point of glass capture within phase space on the basis of the static solutions. One studies p-spin model without magnetic field in case of replica symmetry violation. One studies dynamics of p-spin glass in magnetic field in replica-symmetrical phase. One studied model of spins with quadratic interaction when dynamic constants had temperature differing from temperature of space

Material Targets for Scaling All-Spin Logic

Science.gov (United States)

Manipatruni, Sasikanth; Nikonov, Dmitri E.; Young, Ian A.

2016-01-01

All-spin-logic devices are promising candidates to augment and complement beyond-CMOS integrated circuit computing due to nonvolatility, ultralow operating voltages, higher logical efficiency, and high density integration. However, the path to reach lower energy-delay product performance compared to CMOS transistors currently is not clear. We show that scaling and engineering the nanoscale magnetic materials and interfaces is the key to realizing spin-logic devices that can surpass the energy-delay performance of CMOS transistors. With validated stochastic nanomagnetic and vector spin-transport numerical models, we derive the target material and interface properties for the nanomagnets and channels. We identify promising directions for material engineering and discovery focusing on the systematic scaling of magnetic anisotropy (Hk ) and saturation magnetization (Ms ), the use of perpendicular magnetic anisotropy, and the interface spin-mixing conductance of the ferromagnet-spin-channel interface (Gmix ). We provide systematic targets for scaling a spin-logic energy-delay product toward 2 aJ ns, comprehending the stochastic noise for nanomagnets.

Trade-Off and Synergy among Ecosystem Services in the Guanzhong-Tianshui Economic Region of China.

Science.gov (United States)

Qin, Keyu; Li, Jing; Yang, Xiaonan

2015-11-03

Natural ecosystems provide society with important goods and services. With rapidly increasing populations and excessive utilization of natural resources, humans have been enhancing the production of some services at the expense of others. Although the need for certain trade-offs between conservation and development is urgent, having only a small number of efficient methods to assess such trade-offs has impeded progress. This study focuses on the evaluation of ecosystem services under different land use schemes. It reveals the spatial and temporal distributions of and changes in ecosystem services. Based on a correlation rate model and distribution mapping, the trade-offs and synergies of these ecosystem services can be found. Here, we also describe a new simple approach to quantify the relationships of every trade-off and synergy. The results show that all ecosystem services possess trade-offs and synergies in the study area. The trend of improving carbon sequestration and water interception indicate that these key ecosystem services have the strongest synergy. And the decrease in regional agricultural production and other services, except water yield, may be considered as trade-offs. The synergy between water yield and agricultural production was the most significant, while the trade-off between water interception and carbon sequestration was the most apparent, according to our interaction quantification model. The results of this study have implications for planning and monitoring the future management of natural capital and ecosystem services, and can be integrated into land use decision-making.

Trade-Off and Synergy among Ecosystem Services in the Guanzhong-Tianshui Economic Region of China

Directory of Open Access Journals (Sweden)

Keyu Qin

2015-11-01

Full Text Available Natural ecosystems provide society with important goods and services. With rapidly increasing populations and excessive utilization of natural resources, humans have been enhancing the production of some services at the expense of others. Although the need for certain trade-offs between conservation and development is urgent, having only a small number of efficient methods to assess such trade-offs has impeded progress. This study focuses on the evaluation of ecosystem services under different land use schemes. It reveals the spatial and temporal distributions of and changes in ecosystem services. Based on a correlation rate model and distribution mapping, the trade-offs and synergies of these ecosystem services can be found. Here, we also describe a new simple approach to quantify the relationships of every trade-off and synergy. The results show that all ecosystem services possess trade-offs and synergies in the study area. The trend of improving carbon sequestration and water interception indicate that these key ecosystem services have the strongest synergy. And the decrease in regional agricultural production and other services, except water yield, may be considered as trade-offs. The synergy between water yield and agricultural production was the most significant, while the trade-off between water interception and carbon sequestration was the most apparent, according to our interaction quantification model. The results of this study have implications for planning and monitoring the future management of natural capital and ecosystem services, and can be integrated into land use decision-making.

Production of dimethylsulphide during the seasonal anoxia off Goa

Digital Repository Service at National Institute of Oceanography (India)

Shenoy, D.M.; Sujith, K.B.; Gauns, M.; Patil, S.; Sarkar, Amit; Naik, H.; Narvekar, P.V.; Naqvi, S.W.A.

to better understand the formation of anoxia and its influence on DMS production. Materials and methods: A 3-day observation was carried out at station G5 (Figure 1), which is part of the Candolim times series transect, known in short as CaTS. The quasi...-time series transect (CaTS) was established in 1997 and is located off the coast of Candolim, a coastal village in North Goa. The CaTS-G5 station, which has a depth of approximately 28 m, was occupied from 1340 hours on 25 th September’09 until 1824 hours...

Measurements of the spin structure of the nucleon using SPHICE: A strongly polarized hydrogen and deuterium ice target

International Nuclear Information System (INIS)

Babusci, D.; Blecher, M.; Breuer, M.; Caracappa, A.; Commeaux, C.; Didelez, J.; Fan, Q.; Giordano, G.; Hicks, K.; Hoblit, S.; Hoffmann-Rothe, P.; Honig, A.; Kistner, O.C.; Khandaker, M.; Li, Z.; Lucas, M.A.; Matone, G.; Miceli, L.; Preedom, B.M.; Rigney, M.; Sandorfi, A.M.; Schaerf, C.; Thorn, C.E.

1995-01-01

Frozen-spin HD polarized targets operating between 0.4 and 4K, used with cold-transfer (4K) techniques, provide great configurational flexibility. Their long depolarization times under target usage conditions assure reasonable match between polarization production and usage times, for weakly ionizing beam fluxes, and the very long relaxation times at fields above 7T (∼1 yr.) provide an economical storage mode and open-quote open-quote off-the-shelf close-quote close-quote availability. copyright 1995 American Institute of Physics

THE DISK WIND IN THE RAPIDLY SPINNING STELLAR-MASS BLACK HOLE 4U 1630–472 OBSERVED WITH NuSTAR

Energy Technology Data Exchange (ETDEWEB)

King, Ashley L.; Miller, Jon M. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109-1042 (United States); Walton, Dominic J.; Fürst, Felix; Harrison, Fiona A. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Barret, Didier [Université de Toulouse, UPS-OMP, IRAP, Toulouse (France); Boggs, Steven E.; Craig, William W.; Krivonos, Roman; Tomsick, John A. [Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450 (United States); Christensen, Finn E. [DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Fabian, Andy C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Hailey, Charles J.; Mori, Kaya [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Natalucci, Lorenzo [Istituto Nazionale di Astrofisica, INAF-IAPS, via del Fosso del Cavaliere, I-00133 Roma (Italy); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Mail Stop 169-221, Pasadena, CA 91109 (United States); Zhang, William W., E-mail: ashking@umich.edu [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2014-03-20

We present an analysis of a short NuSTAR observation of the stellar-mass black hole and low-mass X-ray binary 4U 1630–472. Reflection from the inner accretion disk is clearly detected for the first time in this source, owing to the sensitivity of NuSTAR. With fits to the reflection spectrum, we find evidence for a rapidly spinning black hole, a{sub ∗}=0.985{sub −0.014}{sup +0.005} (1σ statistical errors). However, archival data show that the source has relatively low radio luminosity. Recently claimed relationships between jet power and black hole spin would predict either a lower spin or a higher peak radio luminosity. We also report the clear detection of an absorption feature at 7.03 ± 0.03 keV, likely signaling a disk wind. If this line arises in dense, moderately ionized gas (log ξ=3.6{sub −0.3}{sup +0.2}) and is dominated by He-like Fe XXV, the wind has a velocity of v/c=0.043{sub −0.007}{sup +0.002} (12900{sub −2100}{sup +600} km s{sup –1}). If the line is instead associated with a more highly ionized gas (log ξ=6.1{sub −0.6}{sup +0.7}), and is dominated by Fe XXVI, evidence of a blueshift is only marginal, after taking systematic errors into account. Our analysis suggests the ionized wind may be launched within 200-1100 Rg, and may be magnetically driven.

On-chip spin-controlled orbital angular momentum directional coupling

Science.gov (United States)

Xie, Zhenwei; Lei, Ting; Si, Guangyuan; Du, Luping; Lin, Jiao; Min, Changjun; Yuan, Xiaocong

2018-01-01

Optical vortex beams have many potential applications in the particle trapping, quantum encoding, optical orbital angular momentum (OAM) communications and interconnects. However, the on-chip compact OAM detection is still a big challenge. Based on a holographic configuration and a spin-dependent structure design, we propose and demonstrate an on-chip spin-controlled OAM-mode directional coupler, which can couple the OAM signal to different directions due to its topological charge. While the directional coupling function can be switched on/off by altering the spin of incident beam. Both simulation and experimental measurements verify the validity of the proposed approach. This work would benefit the on-chip OAM devices for optical communications and high dimensional quantum coding/decoding in the future.

High spin spectroscopy of 70Ge

International Nuclear Information System (INIS)

Kumar Raju, M.; Sugathan, P.; Seshi Reddy, T.; Thirumala Rao, B.V.; Madhusudhana Rao, P.V.; Muralithar, S.; Singh, R.P.; Bhowmik, R.K.

2011-01-01

Structure of nuclei in mass 70 region is of interest due to presence of a variety of complex phenomenon. In these nuclei rapid change of nuclear shape with proton and neutron numbers, spin and excitation energy. Valance nucleons in f-p-g shell configuration will drive the nuclei towards high deformations. Relatively large values of quadrupole deformation are evident in the even-even nuclei in this region. Present study is aimed to explore the high spin structure of the 70 Ge nucleus. A negative parity structure was reported in an earlier study

Uncovering nonperturbative dynamics of the biased sub-Ohmic spin-boson model with variational matrix product states

Science.gov (United States)

Gonzalez-Ballestero, C.; Schröder, Florian A. Y. N.; Chin, Alex W.

2017-09-01

We study the dynamics of the biased sub-Ohmic spin-boson model by means of a time-dependent variational matrix product state (TDVMPS) algorithm. The evolution of both the system and the environment is obtained in the weak- and the strong-coupling regimes, respectively characterized by damped spin oscillations and by a nonequilibrium process where the spin freezes near its initial state, which are explicitly shown to arise from a variety of reactive environmental quantum dynamics. We also explore the rich phenomenology of the intermediate-coupling case, a nonperturbative regime where the system shows a complex dynamical behavior, combining features of both the weakly and the strongly coupled case in a sequential, time-retarded fashion. Our work demonstrates the potential of TDVMPS methods for exploring otherwise elusive, nonperturbative regimes of complex open quantum systems, and points to the possibilities of exploiting the qualitative, real-time modification of quantum properties induced by nonequilibrium bath dynamics in ultrafast transient processes.

El riesgo de orientación en la inversión en spin-offs universitarias. ¿Existe? ¿Es posible identificarlo en los primeros años de vida?

OpenAIRE

Pombo Romero, Julio; Rodeiro Pazos, David; Rodríguez Gulías, María Jesús

2016-01-01

[ES] Diversos estudios han mostrado evidencias de que las empresas creadas desde las universidades (spin-offs) presentan unas tasas de crecimiento menores que otros tipos de start-ups. Esto puede deberse en parte a que un porcentaje de ellas pueden estar orientadas a dar continuidad a proyectos de investigación en base a ayudas públicas, en lugar de a valorizar resultados de investigación en el mercado. El principal objetivo de este trabajo es contrastar si es posible diferenciar dos tipos de...

Wilson lines, Grassmannians and gauge invariant off-shell amplitudes in N=4 SYM

Energy Technology Data Exchange (ETDEWEB)

Bork, L.V. [Institute for Theoretical and Experimental Physics,Moscow (Russian Federation); The Center for Fundamental and Applied Research,All-Russia Research Institute of Automatics, Moscow (Russian Federation); Onishchenko, A.I. [Bogoliubov Laboratory of Theoretical Physics,Joint Institute for Nuclear Research, Dubna (Russian Federation); Moscow Institute of Physics and Technology State University,Dolgoprudny (Russian Federation); Skobeltsyn Institute of Nuclear Physics, Moscow State University,Moscow (Russian Federation)

2017-04-04

In this paper we consider tree-level gauge invariant off-shell amplitudes (Wilson line form factors) in N=4 SYM. For the off-shell amplitudes with one leg off-shell we present a conjecture for their Grassmannian integral representation in spinor helicity, twistor and momentum twistor parameterizations. The presented conjecture is successfully checked against BCFW results for MHV{sub n}, NMHV{sub 4} and NMHV{sub 5} off-shell amplitudes. We have also verified that our Grassmannian integral representation correctly reproduces soft (on-shell) limit for the off-shell gluon momentum. It is shown that the (deformed) off-shell amplitude expressions could be also obtained using quantum inverse scattering method for auxiliary gl(4|4) super spin chain.

NLO predictions for the production of a (750 GeV) spin-two particle at the LHC

CERN Document Server

Das, Goutam; Hirschi, Valentin; Maltoni, Fabio; Shao, Hua-Sheng

2017-07-10

We obtain predictions accurate at the next-to-leading order in QCD for the production of a generic spin-two particle in the most relevant channels at the LHC: production in association with colored particles (inclusive, one jet, two jets and $t\\bar t$), with vector bosons ($Z,W^\\pm,\\gamma$) and with the Higgs boson. We present total and differential cross sections as well as branching ratios corresponding to a spin-2 particle of 750 GeV of mass, possibly with non-universal couplings to standard model particles, at 13 TeV of center-of-mass energy. We find that the next-to-leading order corrections give rise to sizeable $K$ factors for many channels, in some cases exposing the unitarity-violating behaviour of non-universal couplings scenarios, and in general greatly reduce the theoretical uncertainties. Our predictions are publicly available in the \\amc\\ framework and can, therefore, be directly used in experimental simulations for any value of the mass and couplings.

The problem of the involvement of the off-balance reserves of the metallic ores into the production process

Directory of Open Access Journals (Sweden)

V. I. Golik

2017-12-01

Full Text Available The underground mining of the ore deposits by means of the intensive methods of the traditional technologies is characterized by the loss of the reserves, which are off-balance for the technologies applied. The experience, which was accumulated by the state-of-the-art enterprises before the economic reforms and the crisis indicates, that it is possible to decrease the loss of metals. This can be assumed by means of involving the off-balance reserves into the production process with the metal lixiviation during closed work. The purpose of the present-day research is the substantiation of the technical possibility and economic reasonability of the lixiviation of metals from the off-balance reserves and poorly balance ores. The correct estimation of the perspectives of those combined technology is still one of the purposes. It is a matter of fact that combining traditional technologies of the underground mining with new ones concerned with the creation of the effective lixiviation of metals from ores can be carried out with the two-stage processing. It happens when the excavation of some amount of the balance reserves creates the compensational space for crushing off-balance reserves. Involving off-balance ores into the production process solves a set of the mining production problems. For example, the fullness of mineral resources usage, the strengthening of the resource base, the reduction of load of the environment and the security of works. The involvement of the off-balance reserves into the development in the course of the revaluation of the resources and in the technological facilities of the development in the context of the growth of the scale of production reduces the production price to the competitive level. The field of application of these results is in the mining enterprises which extract solid metal-containing ores by means of the underground mining. These ores are mostly of the nonferrous, rare and precious metals, which are easily

Properties of magnetic impurities embedded into an anisotropic Heisenberg chain with spin gap

International Nuclear Information System (INIS)

Schlottmann, P.

2000-01-01

We consider a U(1)-invariant model consisting of the integrable anisotropic easy-axis Heisenberg chain of arbitrary spin S embedding an impurity of spin S'. The host chain has a spin gap for all values of S. The ground state properties and the elementary excitations of the host are studied as a function of the anisotropy and the magnetic field. The impurity is located on a link of the chain and interacts only with both neighboring sites. The coupling of the impurity to the lattice can be tuned by the impurity rapidity p 0 (usually playing the role of the Kondo coupling). The impurity model is then integrable as a function of two continuous parameters (the anisotropy and the impurity rapidity) and two discrete variables (the spins S and S'). The Bethe ansatz equations are derived and used to obtain the magnetization of the impurity. The impurity magnetization is non-universal as a function of p 0 . For small fields the impurity magnetization is determined by the spin gap and the van Hove singularity of the rapidity band. For an overcompensated impurity (S'< S) at intermediate fields there is a crossover to non-Fermi-liquid behavior remnant from the suppressed quantum critical point

Entangled spin chain

Science.gov (United States)

Salberger, Olof; Korepin, Vladimir

We introduce a new model of interacting spin 1/2. It describes interactions of three nearest neighbors. The Hamiltonian can be expressed in terms of Fredkin gates. The Fredkin gate (also known as the controlled swap gate) is a computational circuit suitable for reversible computing. Our construction generalizes the model presented by Peter Shor and Ramis Movassagh to half-integer spins. Our model can be solved by means of Catalan combinatorics in the form of random walks on the upper half plane of a square lattice (Dyck walks). Each Dyck path can be mapped on a wave function of spins. The ground state is an equally weighted superposition of Dyck walks (instead of Motzkin walks). We can also express it as a matrix product state. We further construct a model of interacting spins 3/2 and greater half-integer spins. The models with higher spins require coloring of Dyck walks. We construct a SU(k) symmetric model (where k is the number of colors). The leading term of the entanglement entropy is then proportional to the square root of the length of the lattice (like in the Shor-Movassagh model). The gap closes as a high power of the length of the lattice [5, 11].

Large-x sub F spin asymmetry in. pi. sup 0 production by 200-GeV polarized protons

Energy Technology Data Exchange (ETDEWEB)

Adams, D L; Corcoran, M D; Cranshaw, J; Nessi-Tedaldi, F; Nessi, M; Nguyen, C; Roberts, J B; Skeens, J; White, J L [Rice Univ., Houston, TX (United States). T.W. Bonner Nuclear Lab.; Akchurin, N; Onel, Y [Iowa Univ., Iowa City, IA (United States). Dept. of Physics; Belikov, N I; Derevschikov, A A; Grachov, O A; Matulenko, Yu A; Meschanin, A P; Nurushev, S B; Patalakha, D I; Rykov, V L; Solovyanov, V L; Vasiliev, A N [Inst. of High Energy Physics, Serpukhov (Russia); Bystricky, J; Lehar, F; Lesquen, A de [CEN-Saclay, 91 - Gif-sur-Yvette (France); Cossairt, J D; Read, A L [Fermi National Accelerator Lab., Batavia, IL (United States); En' yo, H; Funahashi, H; Goto, Y; Imai, K; Itow, Y; Makino, S; Masaike, A; Miyake, K; Nagamine, T; Saito, N; Yamashita, S [Kyoto Univ. (Japan). Dept. of Physics; Grosnick, D P; Hill, D A; Laghai, M; Lopiano, D; Ohashi, Y; Spinka, H; Underwood, D G; Yokosawa, A [Argonne National Lab., IL (United States); FNAL E704 Collaboration

1992-10-01

The spin asymmetry A{sub N} for inclusive {pi}{sup 0} production by 200-GeV transversely-polarized protons on a liquid hydrogen target has been measured at Fermilab over a wide range of x{sub F}, with 0.50.3, the asymmetry rises with increasing x{sub F} and reaches a value of A{sub N}=0.15{+-}0.03 in the region 0.6spin structure of transversely-polarized protons. (orig.).

Effect of stocking biomass on solids, phytoplankton communities, common off-flavors, and production parameters in a channel catfish biofloc technology production system

Science.gov (United States)

The effect of initial channel catfish (Ictalurus punctatus, Rafinesque, 1818) fingerling biomass (1.4, 1.8, or 2.3 kg m-3) on phytoplankton communities, common off-flavors, and stocker catfish production parameters was evaluated in biofloc technology production tanks. Stocker catfish size (145.5 – 1...

Global Navigation Satellite System (GNSS) Rapid Clock Product Summary from NASA CDDIS

Data.gov (United States)

National Aeronautics and Space Administration — This derived product set consists of Global Navigation Satellite System Rapid Clock Product Summary from the NASA Crustal Dynamics Data Information System (CDDIS)....

Polarization and spin effects in production and decay of charginos and neutralinos at a muon collider

Energy Technology Data Exchange (ETDEWEB)

Pahlen, F. von der

2006-06-14

In this thesis we have analyzed the polarization effects of the beams and the charginos and neutralinos produced in {mu}{sup +}{mu}{sup -} annihilation around the center of mass energies of the Higgs boson resonances H and A. we have analyzed the effect of the energy spread and of the error from the non-resonant channels, including an irreducible standard model background contribution. For small tan {beta} the process yields large cross sections of up to a pb. For the production of two different charginos we have shown that the H-A interference can be analyzed using asymmetries of the charge conjugated processes. For the chargino pair production with subsequent two-body decays of both charginos we have defined energy distribution and angular asymmetries in the final particles, in order to analyze the spin-spin correlations of the charginos. For the neutralino pair production in {mu}{sup +}{mu}{sup -} annihilation we study similar processes as for chargino production. Line shape measurements of neutralino pair production allow to precisely determine the ratio of H-neutralino and A-neutralino couplings. For neutralino pair production with subsequent two-body decays of both neutralinos we analyze similar observables as in chargino production. The main difference consists in the intrinsic relative CP quantum number of the neutralino pair, which depends on the chosen scenario. We have thus shown that the interaction of the Higgs bosons to the gaugino-higgsino sector can be probed at a muon collider in chargino and neutralino pair production, both analyzing the production line-shape around the resonances as well as studying the chargino and neutralino polarizations via their decays. (orig.)

Spin Current Noise of the Spin Seebeck Effect and Spin Pumping

Science.gov (United States)

Matsuo, M.; Ohnuma, Y.; Kato, T.; Maekawa, S.

2018-01-01

We theoretically investigate the fluctuation of a pure spin current induced by the spin Seebeck effect and spin pumping in a normal-metal-(NM-)ferromagnet(FM) bilayer system. Starting with a simple ferromagnet-insulator-(FI-)NM interface model with both spin-conserving and non-spin-conserving processes, we derive general expressions of the spin current and the spin-current noise at the interface within second-order perturbation of the FI-NM coupling strength, and estimate them for a yttrium-iron-garnet-platinum interface. We show that the spin-current noise can be used to determine the effective spin carried by a magnon modified by the non-spin-conserving process at the interface. In addition, we show that it provides information on the effective spin of a magnon, heating at the interface under spin pumping, and spin Hall angle of the NM.

One-hadron transverse spin effects on a proton target at COMPASS

Energy Technology Data Exchange (ETDEWEB)

Adolph, Christoph

2013-02-19

distribution functions, the aforementioned transversity and Sivers functions, the worm-gear 2 function and the Pretzelosity function. The other four are of subleading order. The investigation of the structure of the nucleon spin is one of the main goals of the COMPASS experiment at CERN. For the measurement of transverse spin effects a 160 GeV/c polarized μ{sup +} beam is scattered off a polarized nucleon target. In the years 2002-2004 a deuterium ({sup 6}LiD) target was used, while in 2007 and 2010 the measurement was done on a proton (NH{sub 3}) target. In this thesis the methods of analysis and the results for the eight transverse spin dependent distribution functions from the 2010 data-taking period will be shown for unidentified hadrons as well as for identified pions and kaons. Furthermore the Collins and Sivers asymmetries for the production of K{sup 0} are presented. The work is concluded by a comparison of the measured asymmetries with the results of the HERMES experiment at DESY and existing model predictions. A short interpretation of the results for the Collins and Sivers asymmetries is also given.

Observation of linear spin wave dispersion in the reentrant spin glass Fe sub 0 sub . sub 7 Al sub 0 sub . sub 3

CERN Document Server

Shapiro, S M; Raymond, S; Lee, S H; Motoya, K

2002-01-01

Fe sub 0 sub . sub 7 Al sub 0 sub . sub 3 is a reentrant spin glass, which undergoes a transition from a paramagnet to a disordered ferromagnet at T sub c propor to 500 K; at a lower temperature the spins progressively freeze and it exhibits a spin-glass-like behavior. In the ferromagnetic phase spin waves with a q sup 2 dispersion are observed at small q, which broaden rapidly and become diffusive beyond a critical wave vector q sub 0. On cooling the spin waves also disappear and a strong elastic central peak develops. For measurements around the (1,1,1) Bragg peak, a new sharp excitation is observed which has a linear dispersion behavior. It disappears above T sub c , but persists throughout the spin-glass phase. It is not present in the stoichiometric Fe sub 3 Al material. (orig.)

Towards the solution of the nucleon spin problem

International Nuclear Information System (INIS)

Moroz, Z.

1994-01-01

Experimental confirmation of the nucleon quark structure is usually identified with the results of MIT-SLAC inelastic scattering program. In particular, measurements of the cross-sections for the deep inelastic scattering (DIS) of electrons: e + p → e'+X allowed to study a matter granularity of the order of λ < 0.5 fermis. From very beginning DIS of polarized leptons off polarized protons was recognized as an excellent tool for studying of the internal spin structure of nucleons. Already the first studies of the deep inelastic scattering (DIS) of polarized leptons off polarized protons (EMC/CERN and SLAC/Stanford, 1987-88) have shown, that an amount of the proton spin carried by quarks is surprisingly small. This phenomenon was named ''the proton spin crisis''. In this lecture the present status of this subject is reviewed. After an introduction to the polarized DIS, the experimental aspects of the proton spin crisis are discussed. Then, some theoretical explanation of this phenomenon are listed. Recent progress in the obtaining polarized particles inside the storage rings as well as development of the polarized internal gas targets made possible to start new generation of experiments. Two such projects using polarized electrons, namely HERMES and SLAC E-143 as well as the proposed studies of polarized p + p DIS in the storage ring RHIC are presented. Some ideas about future extensions of such experiments are also discussed. Many facts concerning the subject were learned by the author during his participation in FILTEX/HERMES project in Heidelberg. Therefore, all members of this group are warmly acknowledged for many discussions of the problems raised in this lecture. (author). 31 refs, 1 fig., 1 tab

First results for the two-spin parameter ALL in π0 production by 200 GeV polarized protons and antiprotons

International Nuclear Information System (INIS)

Adams, D.L.; Corcoran, M.D.; Cranshaw, J.; Nessi-Tedaldi, F.; Nessi, M.; Nguyen, C.; Roberts, J.B.; Skeens, J.; White, J.L.; Bystricky, J.; Chaumette, P.; Deregel, J.; Durand, G.; Fabre, J.; Lehar, F.; Lesquen, A. de; Cossairt, J.D.; Read, A.L.; En'yo, H.; Funahashi, H.; Goto, Y.; Imai, K.; Itow, Y.; Makino, S.; Masaike, A.; Miyake, K.; Nagamine, T.; Saito, N.; Yamashita, S.; Grosnick, D.P.; Hill, D.A.; Kasprzyk, T.; Laghai, M.; Lopiano, D.; Ohashi, Y.; Shepard, J.; Spinka, H.; Underwood, D.G.; Yokosawa, A.; Iwatani, K.; Krueger, K.W.; Kuroda, K.; Michalowicz, A.; Pauletta, G.; Penzo, A.; Schiavon, P.; Zanetti, A.; Salvato, G.; Villari, A.; Takeutchi, F.; Tamura, N.; Tanaka, N.; Yoshida, T.

1991-01-01

The two-spin parameter A LL in inclusive π 0 production by longitudinally-polarized protons and antiprotons on a longitudinally-polarized proton target has been measured at the 200 GeV Fermilab spin physics facility, for π 0 's at x F = 0 with 1 ≤ p t ≤ 3 GeV/c. The results exclude, at the 95% confidence level, values of A LL (pp) > 0.1 and 0 's produced by protons, and values of A LL (anti pp) > 0.1 and LL (pp) for the gluon spin density is discussed. The data are in good agreement with 'conventional' small or zero, gluon polarization. (orig.)

Off-label use of medical products in radiation therapy: Summary of the Report of AAPM Task Group No. 121

International Nuclear Information System (INIS)

Thomadsen, Bruce R.; Thompson, Heaton H. II; Jani, Shirish K.

2010-01-01

Medical products (devices, drugs, or biologics) contain information in their labeling regarding the manner in which the manufacturer has determined that the products can be used in a safe and effective manner. The Food and Drug Administration (FDA) approves medical products for use for these specific indications which are part of the medical product's labeling. When medical products are used in a manner not specified in the labeling, it is commonly referred to as off-label use. The practice of medicine allows for this off-label use to treat individual patients, but the ethical and legal implications for such unapproved use can be confusing. Although the responsibility and, ultimately, the liability for off-label use often rests with the prescribing physician, medical physicists and others are also responsible for the safe and proper use of the medical products. When these products are used for purposes other than which they were approved, it is important for medical physicists to understand their responsibilities. In the United States, medical products can only be marketed if officially cleared, approved, or licensed by the FDA; they can be used if they are not subject to or specifically exempt from FDA regulations, or if they are being used in research with the appropriate regulatory safeguards. Medical devices are either cleared or approved by FDA's Center for Devices and Radiological Health. Drugs are approved by FDA's Center for Drug Evaluation and Research, and biological products such as vaccines or blood are licensed under a biologics license agreement by FDA's Center for Biologics Evaluation and Research. For the purpose of this report, the process by which the FDA eventually clears, approves, or licenses such products for marketing in the United States will be referred to as approval. This report summarizes the various ways medical products, primarily medical devices, can legally be brought to market in the United States, and includes a discussion of the

Off-label use of medical products in radiation therapy: Summary of the Report of AAPM Task Group No. 121

Energy Technology Data Exchange (ETDEWEB)

Thomadsen, Bruce R.; Thompson, Heaton H. II; Jani, Shirish K. [Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705 (United States); Hagerstown, Maryland 21740 (United States); and others

2010-05-15

Medical products (devices, drugs, or biologics) contain information in their labeling regarding the manner in which the manufacturer has determined that the products can be used in a safe and effective manner. The Food and Drug Administration (FDA) approves medical products for use for these specific indications which are part of the medical product's labeling. When medical products are used in a manner not specified in the labeling, it is commonly referred to as off-label use. The practice of medicine allows for this off-label use to treat individual patients, but the ethical and legal implications for such unapproved use can be confusing. Although the responsibility and, ultimately, the liability for off-label use often rests with the prescribing physician, medical physicists and others are also responsible for the safe and proper use of the medical products. When these products are used for purposes other than which they were approved, it is important for medical physicists to understand their responsibilities. In the United States, medical products can only be marketed if officially cleared, approved, or licensed by the FDA; they can be used if they are not subject to or specifically exempt from FDA regulations, or if they are being used in research with the appropriate regulatory safeguards. Medical devices are either cleared or approved by FDA's Center for Devices and Radiological Health. Drugs are approved by FDA's Center for Drug Evaluation and Research, and biological products such as vaccines or blood are licensed under a biologics license agreement by FDA's Center for Biologics Evaluation and Research. For the purpose of this report, the process by which the FDA eventually clears, approves, or licenses such products for marketing in the United States will be referred to as approval. This report summarizes the various ways medical products, primarily medical devices, can legally be brought to market in the United States, and includes a

How to realize a spin-dependent Seebeck diode effect in metallic zigzag γ-graphyne nanoribbons?

Science.gov (United States)

Wu, Dan-Dan; Liu, Qing-Bo; Fu, Hua-Hua; Wu, Ruqian

2017-11-30

The spin-dependent Seebeck effect (SDSE) is one of the core topics of spin caloritronics. In the traditional device designs of spin-dependent Seebeck rectifiers and diodes, finite spin-dependent band gaps of materials are required to realize the on-off characteristic in thermal spin currents, and nearly zero charge current should be achieved to reduce energy dissipation. Here, we propose that two ferromagnetic zigzag γ-graphyne nanoribbons (ZγGNRs) without any spin-dependent band gaps around the Fermi level can not only exhibit the SDSE, but also display rectifier and diode effects in thermal spin currents characterized by threshold temperatures, which originates from the compensation effect occurring in spin-dependent transmissions but not from the spin-splitting band gaps in materials. The metallic characteristics of ZγGNRs bring about an advantage that the gate voltage is an effective route to adjust the symmetry of spin-splitting bands to obtain pure thermal spin currents. The results provide a new mechanism to realize spin-Seebeck rectifier and diode effects in 2D materials and expand material candidates towards spin-Seebeck device applications.

Rapidity correlations in inclusive two-particle production at storage ring energies

CERN Document Server

Dibon, Heinz; Gottfried, Christian; Nefkens, B M K; Neuhofer, G; Niebergall, F; Regler, Meinhard; Schmidt-Parzefall, W; Schubert, K R; Schumacher, P E; Winter, Klaus

1973-01-01

Inclusive two-particle production in the reaction pp to gamma +ch+ (anything) has been measured at the CERN ISR for four energies ( square root s=23, 30.5, 45, and 53 GeV) at two production angles of the charged particles (ch) and at eight production angles of the gamma -rays. The rapidity correlation of the two particles is weak and of short range. The peak correlation is sigma /sub inel/(d/sup 2/ sigma /sub gamma ch//d sigma /sub gamma /d sigma /sub ch/)-1=0.62+or-0.08, the correlation range (y/sub gamma /-y/sub ch/)=1.17+or-0.05, independently of s. The phi correlation extends over a wide gap in rapidity; its strength is increasing with increasing transverse momentum. (7 refs).

Two-photon spin generation and detection

International Nuclear Information System (INIS)

Miah, M Idrish

2009-01-01

A time- and polarization-resolved two-photon pump-probe investigation is performed in lightly doped GaAs. We generate spin-polarized electrons in bulk GaAs at various temperatures using right-circularly polarized two-photon excitation and detect them by probing the spin-dependent transmission of the sample. The spin polarization (P) of conduction band electrons, as measured using probe pulses with the same (right) and opposite (left) circular polarization, is measured in dependences of pump-probe delay (Δt), lattice temperature (T L ), doping density (n) as well as of the excess photon energy ΔE 2ω = ℎ2ω - E g , where E g is the band gap energy. P is found to be decayed with Δt and enhanced with the decrease in T L or the increase in n. It is also found that P decreases with the increase in ΔE 2ω and depolarizes rapidly for ΔE 2ω > ΔE SO , where ΔE SO is the spin-orbit splitting energy. The results demonstrate that due to a much longer absorption depth highly polarized spins can be generated optically by two-photon pumping of bulk semiconductors.

Single transverse-spin asymmetric in hardronic collisions

International Nuclear Information System (INIS)

Qiu, J.

1995-01-01

We provide a consistent treatment of single transverse-spin asymmetriesin hadronic collisions in terms of the generalized factorization theorem in perturbative QCD. The asymmetries in different physical processes, such as direct photon, single particle production, can be expressed in terms of a calculable partonic hard-part convoluted with universal three-parton correlation functions. We show that the observed single transverse- spin asymmtries in hadronic pion production can be understood, and used to extract the information on these correlation functions. With these correlation functions, predictions on single spin asymmetries in other processes can be made, and consequently, the theory can be tested

Data bases for rapid response to power reactor problems

International Nuclear Information System (INIS)

Maskewitz, B.F.

1980-01-01

The urgency of the TMI-2 incident demanded prompt answers to an imperious situation. In responding to these challenging circumstances, both government and industry recognized deficiencies in both availability of essential retrievable data and calculational capabilities designed to respond immediately to actual abnormal events. Each responded by initiating new programs to provide a remedy for the deficiencies and to generally improve all safety measures in the nuclear power industry. Many data bases and information centers offer generic data and other technology resources which are generally useful in support of nuclear safety programs. A few centers can offer rapid access to calculational methods and associated data and more will make an effort to do so. As a beneficial spin-off from the lessons learned from TMI-2, more technical effort and financial resources will be devoted to the prevention of accidents, and to improvement of safety measures in the immediate future and for long term R and D programs by both government and the nuclear power industry

"Iron-Clad" Evidence For Spinning Black Hole

Science.gov (United States)

2003-09-01

competing explanations that do not require extreme gravitational effects, and provide the best look yet at the geometry of the space-time around a stellar black hole created by the death of a massive star." The orbit of a particle near a black hole depends on the curvature of space around the black hole, which also depends on how fast the black hole is spinning. A spinning black hole drags space around with it and allows atoms to orbit closer to the black hole than is possible for a non-spinning black hole. The latest Chandra data from Cygnus X-1, the first stellar-size black hole discovered, show that the gravitational effects on the signal from the iron atoms can only be due to relativistic effects, and that some of the atoms are no closer than 100 miles to the black hole. There was no evidence that the Cygnus X-1 black hole is spinning. The XMM-Newton data from the black hole, XTE J1650-500, show a very similar distribution of iron atom X-rays with one important exception. More low energy X-rays from iron atoms are observed, an indication that some X-rays are coming from deep in the gravitational well around the black hole, as close as 20 miles to the black hole event horizon. This black hole must be spinning rapidly. Chandra observations of a third stellar black hole, GX 339-4, have revealed that it is also spinning rapidly, and clouds of warm absorbing gas appear to be flowing away from the black hole at speeds of about three hundred thousand miles per hour. Such warm gas flows have been observed in the vicinity of supermassive black holes. Previous observations of some supermassive black holes by Japan's ASCA satellite, XMM-Newton and Chandra have indicated that they may also be rotating rapidly. The latest results presented by Miller indicate that the peculiar geometry of space around spinning stellar-mass black holes and supermassive black holes is remarkably similar. Stellar and supermassive black holes may be similar in other ways. Powerful jets of high

Geometrical spin symmetry and spin

International Nuclear Information System (INIS)

Pestov, I. B.

2011-01-01

Unification of General Theory of Relativity and Quantum Mechanics leads to General Quantum Mechanics which includes into itself spindynamics as a theory of spin phenomena. The key concepts of spindynamics are geometrical spin symmetry and the spin field (space of defining representation of spin symmetry). The essence of spin is the bipolar structure of geometrical spin symmetry induced by the gravitational potential. The bipolar structure provides a natural derivation of the equations of spindynamics. Spindynamics involves all phenomena connected with spin and provides new understanding of the strong interaction.

Single spin asymmetry in inclusive pion production, Collins effect and the string model

International Nuclear Information System (INIS)

Artru, X.; Czyzewski, J.; Yabuki, H.

1994-05-01

We calculate the single spin asymmetry in the inclusive pion production in proton-proton collisions. We generate the asymmetry at the level of fragmentation function (Collins effect) by the Lund coloured string mechanism. We compare our results with the Fermilab E704 data from p ↑p collisions at 200 GeV. We show that the transversely polarized quark densities at high Bjorken x strongly differ from these predicted by the SU(6) proton wave function. (authors). 18 refs., 7 figs

Tailoring Cu Nanoparticle Catalyst for Methanol Synthesis Using the Spinning Disk Reactor

Directory of Open Access Journals (Sweden)

Christian Ahoba-Sam

2018-01-01

Full Text Available Cu nanoparticles are known to be very active for methanol (MeOH synthesis at relatively low temperatures, such that smaller particle sizes yield better MeOH productivity. We aimed to control Cu nanoparticle (NP size and size distribution for catalysing MeOH synthesis, by using the spinning disk reactor. The spinning disk reactor (SDR, which operates based on shear effect and plug flow in thin films, can be used to rapidly micro-mix reactants in order to control nucleation and particle growth for uniform particle size distribution. This could be achieved by varying both physical and chemical operation conditions in a precipitation reaction on the SDR. We have used the SDR for a Cu borohydride reduction to vary Cu NP size from 3 nm to about 55 nm. XRD and TEM characterization confirmed the presence of Cu2O and Cu crystallites when the samples were dried. This technique is readily scalable for Cu NP production by processing continuously over a longer duration than the small-scale tests. However, separation of the nanoparticles from solution posed a challenge as the suspension hardly settled. The Cu NPs produced were tested to be active catalyst for MeOH synthesis at low temperature and MeOH productivity increased with decreasing particle size.

Topical review: spins and mechanics in diamond

Science.gov (United States)

Lee, Donghun; Lee, Kenneth W.; Cady, Jeffrey V.; Ovartchaiyapong, Preeti; Bleszynski Jayich, Ania C.

2017-03-01

There has been rapidly growing interest in hybrid quantum devices involving a solid-state spin and a macroscopic mechanical oscillator. Such hybrid devices create exciting opportunities to mediate interactions between disparate quantum bits (qubits) and to explore the quantum regime of macroscopic mechanical objects. In particular, a system consisting of the nitrogen-vacancy defect center (NV center) in diamond coupled to a high-quality-factor mechanical oscillator is an appealing candidate for such a hybrid quantum device, as it utilizes the highly coherent and versatile spin properties of the defect center. In this paper, we will review recent experimental progress on diamond-based hybrid quantum devices in which the spin and orbital dynamics of single defects are driven by the motion of a mechanical oscillator. In addition, we discuss prospective applications for this device, including long-range, phonon-mediated spin-spin interactions, and phonon cooling in the quantum regime. We conclude the review by evaluating the experimental limitations of current devices and identifying alternative device architectures that may reach the strong coupling regime.

Generation of genealogical spin eigenfunctions

International Nuclear Information System (INIS)

Grabenstetter, J.E.; Tseng, T.J.; Grein, F.

1976-01-01

A method is given for generating the Yamanouchi-Kotani genealogical spin eigenfunctions which requires neither storage of eigenfunctions for smaller numbers of electrons, nor summations of large order, nor explicit use of results from the theory of representations of the symmetric group. An explicit formula is given for the coefficients of expansion in terms of spin products

Rapid-scan EPR imaging.

Science.gov (United States)

Eaton, Sandra S; Shi, Yilin; Woodcock, Lukas; Buchanan, Laura A; McPeak, Joseph; Quine, Richard W; Rinard, George A; Epel, Boris; Halpern, Howard J; Eaton, Gareth R

2017-07-01

In rapid-scan EPR the magnetic field or frequency is repeatedly scanned through the spectrum at rates that are much faster than in conventional continuous wave EPR. The signal is directly-detected with a mixer at the source frequency. Rapid-scan EPR is particularly advantageous when the scan rate through resonance is fast relative to electron spin relaxation rates. In such scans, there may be oscillations on the trailing edge of the spectrum. These oscillations can be removed by mathematical deconvolution to recover the slow-scan absorption spectrum. In cases of inhomogeneous broadening, the oscillations may interfere destructively to the extent that they are not visible. The deconvolution can be used even when it is not required, so spectra can be obtained in which some portions of the spectrum are in the rapid-scan regime and some are not. The technology developed for rapid-scan EPR can be applied generally so long as spectra are obtained in the linear response region. The detection of the full spectrum in each scan, the ability to use higher microwave power without saturation, and the noise filtering inherent in coherent averaging results in substantial improvement in signal-to-noise relative to conventional continuous wave spectroscopy, which is particularly advantageous for low-frequency EPR imaging. This overview describes the principles of rapid-scan EPR and the hardware used to generate the spectra. Examples are provided of its application to imaging of nitroxide radicals, diradicals, and spin-trapped radicals at a Larmor frequency of ca. 250MHz. Copyright © 2017 Elsevier Inc. All rights reserved.

Grassmannian integral for general gauge invariant off-shell amplitudes in N=4 SYM

Energy Technology Data Exchange (ETDEWEB)

Bork, L.V. [Institute for Theoretical and Experimental Physics,Moscow (Russian Federation); The Center for Fundamental and Applied Research,All-Russia Research Institute of Automatics, Moscow (Russian Federation); Onishchenko, A.I. [Bogoliubov Laboratory of Theoretical Physics,JointInstitute for Nuclear Research, Dubna (Russian Federation); Moscow Institute of Physics and Technology, State University,Dolgoprudny (Russian Federation); Skobeltsyn Institute of Nuclear Physics, Moscow State University,Moscow (Russian Federation)

2017-05-08

In this paper we consider tree-level gauge invariant off-shell amplitudes (Wilson line form factors) in N=4 SYM with arbitrary number of off-shell gluons or equivalently Wilson line operator insertions. We make a conjecture for the Grassmannian integral representation for such objects and verify our conjecture on several examples. It is remarkable that in our formulation one can consider situation when on-shell particles are not present at all, i.e. we have Grassmannian integral representation for purely off-shell object. In addition we show that off-shell amplitude with arbitrary number of off-shell gluons could be also obtained using quantum inverse scattering method for auxiliary gl(4|4) super spin chain.

Rapid Source Characterization of the 2011 Mw 9.0 off the Pacific coast of Tohoku Earthquake

Science.gov (United States)

Hayes, Gavin P.

2011-01-01

On March 11th, 2011, a moment magnitude 9.0 earthquake struck off the coast of northeast Honshu, Japan, generating what may well turn out to be the most costly natural disaster ever. In the hours following the event, the U.S. Geological Survey National Earthquake Information Center led a rapid response to characterize the earthquake in terms of its location, size, faulting source, shaking and slip distributions, and population exposure, in order to place the disaster in a framework necessary for timely humanitarian response. As part of this effort, fast finite-fault inversions using globally distributed body- and surface-wave data were used to estimate the slip distribution of the earthquake rupture. Models generated within 7 hours of the earthquake origin time indicated that the event ruptured a fault up to 300 km long, roughly centered on the earthquake hypocenter, and involved peak slips of 20 m or more. Updates since this preliminary solution improve the details of this inversion solution and thus our understanding of the rupture process. However, significant observations such as the up-dip nature of rupture propagation and the along-strike length of faulting did not significantly change, demonstrating the usefulness of rapid source characterization for understanding the first order characteristics of major earthquakes.

Superconducting spin switch based on superconductor-ferromagnet nanostructures for spintronics

International Nuclear Information System (INIS)

Kehrle, Jan; Mueller, Claus; Obermeier, Guenter; Schreck, Matthias; Gsell, Stefan; Horn, Siegfried; Tidecks, Reinhard; Zdravkov, Vladimir; Morari, Roman; Sidorencko, Anatoli; Prepelitsa, Andrei; Antropov, Evgenii; Socrovisciiuc, Alexei; Nold, Eberhard; Tagirov, Lenar

2011-01-01

Very rapid developing area, spintronics, needs new devices, based on new physical principles. One of such devices - a superconducting spin-switch, consists of ferromagnetic and superconducting layers, and is based on a new phenomenon - reentrant superconductivity. The tuning of the superconducting and ferromagnetic layers thickness is investigated to optimize superconducting spin-switch effect for Nb/Cu 41 Ni 59 based nanoscale layered systems.

Electric-field-controlled spin reversal in a quantum dot with ferromagnetic contacts

Science.gov (United States)

Hauptmann, J. R.; Paaske, J.; Lindelof, P. E.

2008-05-01

Manipulation of the spin states of a quantum dot by purely electrical means is a highly desirable property of fundamental importance for the development of spintronic devices such as spin filters, spin transistors and single spin memories as well as for solid-state qubits. An electrically gated quantum dot in the Coulomb blockade regime can be tuned to hold a single unpaired spin-1/2, which is routinely spin polarized by an applied magnetic field. Using ferromagnetic electrodes, however, the quantum dot becomes spin polarized by the local exchange field. Here, we report on the experimental realization of this tunnelling-induced spin splitting in a carbon-nanotube quantum dot coupled to ferromagnetic nickel electrodes with a strong tunnel coupling ensuring a sizeable exchange field. As charge transport in this regime is dominated by the Kondo effect, we can use this sharp many-body resonance to read off the local spin polarization from the measured bias spectroscopy. We demonstrate that the exchange field can be compensated by an external magnetic field, thus restoring a zero-bias Kondo resonance, and we demonstrate that the exchange field itself, and hence the local spin polarization, can be tuned and reversed merely by tuning the gate voltage.

Green marketing - How to put an environmental spin on your energy product, service, program or project

International Nuclear Information System (INIS)

Flynn, J.

1992-01-01

This paper examines how some smart marketers have quickly picked up on the new consumer interest in protecting the environment, turned it into increased sales and profits and at the same time effectively increased energy conservation. They asked their product developers to improve the environmental benefits of their existing products and to design some new ones. Then they asked their advertising writers to put an environmental spin on their product advertising. Next they made frequent visits to the bank with the increased sales revenues from an expanding market share and at the same time are doing something worthwhile in energy and environmental conservation

Resummation improved rapidity spectrum for gluon fusion Higgs production

International Nuclear Information System (INIS)

Ebert, Markus A.; Tackmann, Frank J.; Michel, Johannes K.L.; Muenster Univ.

2017-02-01

Gluon-induced processes such as Higgs production typically exhibit large perturbative corrections. These partially arise from large virtual corrections to the gluon form factor, which at timelike momentum transfer contains Sudakov logarithms evaluated at negative arguments ln 2 (-1)=-π 2 . It has been observed that resumming these terms in the timelike form factor leads to a much improved perturbative convergence for the total cross section. We discuss how to consistently incorporate the resummed form factor into the perturbative predictions for generic cross sections differential in the Born kinematics, including in particular the Higgs rapidity spectrum. We verify that this indeed improves the perturbative convergence, leading to smaller and more reliable perturbative uncertainties, and that this is not affected by cancellations between resummed and unresummed contributions. Combining both fixed-order and resummation uncertainties, the perturbative uncertainty for the total cross section at N 3 LO+N 3 LL φ ' is about a factor of two smaller than at N 3 LO. The perturbative uncertainty of the rapidity spectrum at NNLO+NNLL φ ' is similarly reduced compared to NNLO. We also study the analogous resummation for quark-induced processes, namely Higgs production through bottom quark annihilation and the Drell-Yan rapidity spectrum. For the former the resummation leads to a small improvement, while for the latter it confirms the already small uncertainties of the fixed-order predictions.

Spin Torques in Systems with Spin Filtering and Spin Orbit Interaction

KAUST Repository

Ortiz Pauyac, Christian

2016-06-19

In the present thesis we introduce the reader to the field of spintronics and explore new phenomena, such as spin transfer torques, spin filtering, and three types of spin-orbit torques, Rashba, spin Hall, and spin swapping, which have emerged very recently and are promising candidates for a new generation of memory devices in computer technology. A general overview of these phenomena is presented in Chap. 1. In Chap. 2 we study spin transfer torques in tunnel junctions in the presence of spin filtering. In Chap. 3 we discuss the Rashba torque in ferromagnetic films, and in Chap. 4 we study spin Hall effect and spin swapping in ferromagnetic films, exploring the nature of spin-orbit torques based on these mechanisms. Conclusions and perspectives are summarized in Chap. 5.

Preference Evaluation System for Construction Products Using QFD-TOPSIS Logic by Considering Trade-Off Technical Characteristics

Directory of Open Access Journals (Sweden)

Jaeho Cho

2017-01-01

Full Text Available This paper investigates the feasibility of quality function deployment, technique for the order of preference by similarity to ideal solution (QFD-TOPSIS in presenting user preferences for multiple alternatives, such as construction technologies, products, systems, and design solutions, with trade-off technical characteristics (TC. The original QFD as house of quality (HOQ defines the requirements and features as subjective matrix relations, which cause interpretations to vary across users and limit its industrial applications. QFD-TOPSIS is a new model that combines the benefits of QFD with those of TOPSIS, maintains the subjectivity and objectivity evaluation of the technical characteristics (TC, and rates the preferences by considering users’ individual propensity for requirements. In addition, QFD-TOPSIS rates the preferences through the reciprocal compensation effects of trade-off TC and filters unsuitable alternatives with predefined restrictive conditions. Trade-off refers to conflicts and/or contradictions between attributes, often arising in multicriteria decision-making. Users or project stakeholder groups define the priorities of trade-off TC that directly influence product preferences and decision-making. In the present study, we have developed a Web system based on the QFD-TOPSIS logic and tested its operation to verify its industrial applicability and viability for automatic quality evaluation.

Spin-polarized spin excitation spectroscopy

International Nuclear Information System (INIS)

Loth, Sebastian; Lutz, Christopher P; Heinrich, Andreas J

2010-01-01

We report on the spin dependence of elastic and inelastic electron tunneling through transition metal atoms. Mn, Fe and Cu atoms were deposited onto a monolayer of Cu 2 N on Cu(100) and individually addressed with the probe tip of a scanning tunneling microscope. Electrons tunneling between the tip and the substrate exchange energy and spin angular momentum with the surface-bound magnetic atoms. The conservation of energy during the tunneling process results in a distinct onset threshold voltage above which the tunneling electrons create spin excitations in the Mn and Fe atoms. Here we show that the additional conservation of spin angular momentum leads to different cross-sections for spin excitations depending on the relative alignment of the surface spin and the spin of the tunneling electron. For this purpose, we developed a technique for measuring the same local spin with a spin-polarized and a non-spin-polarized tip by exchanging the last apex atom of the probe tip between different transition metal atoms. We derive a quantitative model describing the observed excitation cross-sections on the basis of an exchange scattering process.

Leading research report for fiscal 1999. Fundamental technology of spin electronic device; 1999 nendo spin toronikusu soshi kiban gijutsu kenkyu hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

The project, with attention paid to both spin and charge of electrons, aims to draw the best of the said two attributes of electrons by use of the state of the art in manufacturing technology for the creation of novel electronic devices. The nonvolatile MRAM (magnetic random access memory), which is the nearest to commercialization, is a tunnel device consisting of two sheet-shape ferromagnetic metal electrodes and an insulator film sandwiched between the said two electrodes, with the lower electrode magnetized only in one direction. The tunnel resistance changes when the magnetization direction in the upper electrode changes left and right (1, 0) according to an external writing magnetic field, and this enables nondestructive readout. The upper electrode magnetization direction remains unchanged thanks to hysteresis when the external writing magnetic field is turned off, and this allows the device to serve as a nonvolatile memory device. The device has a potential for higher speeds and enhanced integration. Much is also expected from a spin conduction functional device utilizing spin-dependent electric conduction, spin optical function device, spin quantum calculation directly utilizing quantum state, magnetic field sensor, etc. Their importance is great economically and socially, and technologies relating to magnetism and semiconductor should be merged for their further development. (NEDO)

Femtosecond time-resolved optical and Raman spectroscopy of photoinduced spin crossover: temporal resolution of low-to-high spin optical switching.

Science.gov (United States)

Smeigh, Amanda L; Creelman, Mark; Mathies, Richard A; McCusker, James K

2008-10-29

A combination of femtosecond electronic absorption and stimulated Raman spectroscopies has been employed to determine the kinetics associated with low-spin to high-spin conversion following charge-transfer excitation of a FeII spin-crossover system in solution. A time constant of tau = 190 +/- 50 fs for the formation of the 5T2 ligand-field state was assigned based on the establishment of two isosbestic points in the ultraviolet in conjunction with changes in ligand stretching frequencies and Raman scattering amplitudes; additional dynamics observed in both the electronic and vibrational spectra further indicate that vibrational relaxation in the high-spin state occurs with a time constant of ca. 10 ps. The results set an important precedent for extremely rapid, formally forbidden (DeltaS = 2) nonradiative relaxation as well as defining the time scale for intramolecular optical switching between two electronic states possessing vastly different spectroscopic, geometric, and magnetic properties.

Spinning of refractory metals

International Nuclear Information System (INIS)

Chang Wenkua; Zheng Han

1989-01-01

The effects of spinning process parameters including max. pass percentage reduction, spinning temperature, feed rate, lubricant and annealing technology on the quality of shaped components are summarized and discussed in the present paper. The above mentioned parameters are adopted in the process of spinning of barrel-shaped and specially shaped components of refractory metals and their alloys W, Mo, Nb, Zr, TZM molybdenum alloy, C-103, C-752 niobium alloy etc. The cause of leading to usual defects of spun products of refractory metals such as lamellar as 'scaling', crack, swelling, wrinkle, etc. have been analysed and the ways to eliminate the defects have been put forward. 8 figs., 5 tabs. (Author)

A novel reconfigurable electromagnetically induced transparency based on S-PINs

Science.gov (United States)

Xue, Feng; Liu, Shao-Bin; Zhang, Hai-Feng; Wen, Yong-Diao; Kong, Xiang-Kun; Li, Hai-Ming

2018-02-01

In this paper, a tunable electromagnetically induced transparency (EIT) based on S-PINs is theoretically analyzed. Unit cell of the structure consists of a cutwire (CW), split ring resonator (SRR), and solid state plasma (SS plasma) patches which are composed of S-PIN array. The destructive interference between the CW and SRR results in a narrowband transparency window accompanied with strong phase dispersion. The proposed design can obtain a tunable EIT with different frequencies range from 12.8 GHz to 16.5 GHz in a simple method by switching these S-PINs on or off selectively. The related parameters of the S-PIN such as the size, carrier concentration, and volt-ampere characteristics have been studied theoretically. The interaction and coupling between two resonators are investigated in detail by the analysis of the current distribution and E-field strength as well. The research results provide an effective way to realize reconfigurable compact slow-light devices.

Two-photon spin generation and detection

Energy Technology Data Exchange (ETDEWEB)

Miah, M Idrish, E-mail: m.miah@griffith.edu.a [Nanoscale Science and Technology Centre, Griffith University, Nathan, Brisbane, QLD 4111 (Australia)

2009-02-21

A time- and polarization-resolved two-photon pump-probe investigation is performed in lightly doped GaAs. We generate spin-polarized electrons in bulk GaAs at various temperatures using right-circularly polarized two-photon excitation and detect them by probing the spin-dependent transmission of the sample. The spin polarization (P) of conduction band electrons, as measured using probe pulses with the same (right) and opposite (left) circular polarization, is measured in dependences of pump-probe delay ({Delta}t), lattice temperature (T{sub L}), doping density (n) as well as of the excess photon energy {Delta}E{sub 2{omega}}= {h_bar}2{omega} - E{sub g}, where E{sub g} is the band gap energy. P is found to be decayed with {Delta}t and enhanced with the decrease in T{sub L} or the increase in n. It is also found that P decreases with the increase in {Delta}E{sub 2{omega}}and depolarizes rapidly for {Delta}E{sub 2{omega}}> {Delta}E{sub SO}, where {Delta}E{sub SO} is the spin-orbit splitting energy. The results demonstrate that due to a much longer absorption depth highly polarized spins can be generated optically by two-photon pumping of bulk semiconductors.

Weak pion production off the nucleon

International Nuclear Information System (INIS)

Hernandez, E.; Nieves, J.; Valverde, M.

2007-01-01

We develop a model for the weak pion production off the nucleon, which besides the delta pole mechanism [weak excitation of the Δ(1232) resonance and its subsequent decay into Nπ], includes also some background terms required by chiral symmetry. We refit the C 5 A (q 2 ) form factor to the flux-averaged ν μ p→μ - pπ + ANL q 2 -differential cross section data, finding a substantially smaller contribution of the delta pole mechanism than traditionally assumed in the literature. Within this scheme, we calculate several differential and integrated cross sections, including pion angular distributions, induced by neutrinos and antineutrinos and driven both by charged and neutral currents. In all cases we find that the background terms produce quite significant effects, and that they lead to an overall improved description of the data, as compared to the case where only the delta pole mechanism is considered. We also show that the interference between the delta pole and the background terms produces parity-violating contributions to the pion angular differential cross section, which are intimately linked to T-odd correlations in the contraction between the leptonic and hadronic tensors. However, these latter correlations do not imply a genuine violation of time-reversal invariance because of the existence of strong final state interaction effects

Tuning spin transport across two-dimensional organometallic junctions

Science.gov (United States)

Liu, Shuanglong; Wang, Yun-Peng; Li, Xiangguo; Fry, James N.; Cheng, Hai-Ping

2018-01-01

We study via first-principles modeling and simulation two-dimensional spintronic junctions made of metal-organic frameworks consisting of two Mn-phthalocyanine ferromagnetic metal leads and semiconducting Ni-phthalocyanine channels of various lengths. These systems exhibit a large tunneling magnetoresistance ratio; the transmission functions of such junctions can be tuned using gate voltage by three orders of magnitude. We find that the origin of this drastic change lies in the orbital alignment and hybridization between the leads and the center electronic states. With physical insight into the observed on-off phenomenon, we predict a gate-controlled spin current switch based on two-dimensional crystallines and offer general guidelines for designing spin junctions using 2D materials.

PREFACE: Spin Electronics

Science.gov (United States)

Dieny, B.; Sousa, R.; Prejbeanu, L.

2007-04-01

tunnel junctions were introduced as memory elements in new types of non-volatile magnetic memories (MRAM). A first 4Mbit product was launched by Freescale in July 2006. Future generations of memories are being developed by academic groups or companies. the combination of magnetic elements with CMOS components opens a whole new paradigm in hybrid electronic components which can change the common conception of the architecture of complex electronic components with a much tighter integration of logic and memory. the steady magnetic excitations stimulated by spin-transfer might be used in a variety of microwave components provided the output power can be increased. Intense research and development efforts are being aimed at increasing this power by the synchronization of oscillators. The articles compiled in this special issue of Journal of Physics: Condensed Matter, devoted to spin electronics, review these recent developments. All the contributors are greatly acknowledged.

Characterization of aluminium alloys rapidly solidified

International Nuclear Information System (INIS)

Monteiro, W.A.

1988-01-01

This paper discussed the investigation of the microstructural and mechanical properties of the aluminium alloys (3003; 7050; Al-9% Mg) rapidly solidified by melt spinning process (cooling rate 10 4 - 10 6 K/s). The rapidly solidification process of the studied aluminium alloys brought a microcrystallinity, a minimum presence of coarse precipitation and, also, better mechanical properties of them comparing to the same alloys using ingot process. (author) [pt

Secondary proton production at small atmospheric depths as a function of the geomagnetic cut-off

Energy Technology Data Exchange (ETDEWEB)

Papini, P. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Grimani, C. [Perugia Univ. (Italy)]|[INFN, Perugia (Italy); Stephens, S.A. [Tata Institute of Fundamental Research, Bombay (International Commission on Radiation Units and Measurements)

1995-09-01

A detailed calculation of the energy spectrum of secondary protons in the atmosphere is being carried out in the energy range 20 MeV - 40 GeV. In this calculation, it is taken into account all processes leading to the production of secondary protons as a function of the atmospheric depth has been calculated using all relevant energy loss processes. In this paper, it is examine the effect of the geomagnetic cut-off on the spectral shape of secondary protons specially at energies below the geomagnetic cut-off for small atmospheric depths.

Secondary proton production at small atmospheric depths as a function of the geomagnetic cut-off

International Nuclear Information System (INIS)

Papini, P.; Grimani, C.; Stephens, S.A.

1995-01-01

A detailed calculation of the energy spectrum of secondary protons in the atmosphere is being carried out in the energy range 20 MeV - 40 GeV. In this calculation, it is taken into account all processes leading to the production of secondary protons as a function of the atmospheric depth has been calculated using all relevant energy loss processes. In this paper, it is examine the effect of the geomagnetic cut-off on the spectral shape of secondary protons specially at energies below the geomagnetic cut-off for small atmospheric depths

Spin echo dynamics under an applied drift field in graphene nanoribbon superlattices

Energy Technology Data Exchange (ETDEWEB)

Prabhakar, Sanjay, E-mail: sprabhakar@wlu.ca [M 2NeT Laboratory, Wilfrid Laurier University, 75 University Avenue West, Waterloo, Ontario N2L 3C5 (Canada); Melnik, Roderick [M 2NeT Laboratory, Wilfrid Laurier University, 75 University Avenue West, Waterloo, Ontario N2L 3C5 (Canada); Gregorio Millan Institute, Universidad Carlos III de Madrid, 28911 Leganes (Spain); Bonilla, Luis L. [Gregorio Millan Institute, Universidad Carlos III de Madrid, 28911 Leganes (Spain); Raynolds, James E. [Drinker Biddle and Reath LLP, Washington, DC 20005 (United States)

2013-12-02

We investigate the evolution of spin dynamics in graphene nanoribbon superlattices (GNSLs) with armchair and zigzag edges in the presence of a drift field. We determine the exact evolution operator and show that it exhibits spin echo phenomena due to rapid oscillations of the quantum states along the ribbon. The evolution of the spin polarization is accompanied by strong beating patterns. We also provide detailed analysis of the band structure of GNSLs with armchair and zigzag edges.

Spin echo dynamics under an applied drift field in graphene nanoribbon superlattices

International Nuclear Information System (INIS)

Prabhakar, Sanjay; Melnik, Roderick; Bonilla, Luis L.; Raynolds, James E.

2013-01-01

We investigate the evolution of spin dynamics in graphene nanoribbon superlattices (GNSLs) with armchair and zigzag edges in the presence of a drift field. We determine the exact evolution operator and show that it exhibits spin echo phenomena due to rapid oscillations of the quantum states along the ribbon. The evolution of the spin polarization is accompanied by strong beating patterns. We also provide detailed analysis of the band structure of GNSLs with armchair and zigzag edges

The advancement of fuel cell systems and spin-off battery technology. [PAFC, MCFC, SOFC, AFC, PEMFC, Zn/MnO=2-battery, MnO sub 2 /H sub 2 -battery

Energy Technology Data Exchange (ETDEWEB)

Kordesch, K [Technische Univ., Graz (Austria). Inst. fuer Chemische Technologie Anorganischer Stoffe

1990-09-01

The possibly large influence of fuel cell technology on several energy conversion and environmental aspects of the future is discussed. Solar energy and other renewable energy sources must have electrochemical storage facilities. Nuclear power can be used efficiently to electrolize water. The replacement of combustion engines in vehicles by fuel cell systems operating on hydrogen is the only way of reducing the increase of CO{sub 2} in the atmosphere if the greenhouse effect is becoming a threat. The fuel cell projects related to the manned space vehicles can provide many important spin-off's for accumulator designs and battery technology. (orig.).

Chandra Data Reveal Rapidly Whirling Black Holes

Science.gov (United States)

2008-01-01

A new study using results from NASA's Chandra X-ray Observatory provides one of the best pieces of evidence yet that many supermassive black holes are spinning extremely rapidly. The whirling of these giant black holes drives powerful jets that pump huge amounts of energy into their environment and affects galaxy growth. A team of scientists compared leading theories of jets produced by rotating supermassive black holes with Chandra data. A sampling of nine giant galaxies that exhibit large disturbances in their gaseous atmospheres showed that the central black holes in these galaxies must be spinning at near their maximum rates. People Who Read This Also Read... NASA’s Swift Satellite Catches First Supernova in The Act of Exploding Black Holes Have Simple Feeding Habits Jet Power and Black Hole Assortment Revealed in New Chandra Image Erratic Black Hole Regulates Itself "We think these monster black holes are spinning close to the limit set by Einstein's theory of relativity, which means that they can drag material around them at close to the speed of light," said Rodrigo Nemmen, a visiting graduate student at Penn State University, and lead author of a paper on the new results presented at American Astronomical Society in Austin, Texas. The research reinforces other, less direct methods previously used which have indicated that some stellar and supermassive black holes are spinning rapidly. According to Einstein's theory, a rapidly spinning black hole makes space itself rotate. This effect, coupled with gas spiraling toward the black hole, can produce a rotating, tightly wound vertical tower of magnetic field that flings a large fraction of the inflowing gas away from the vicinity of the black hole in an energetic, high-speed jet. Computer simulations by other authors have suggested that black holes may acquire their rapid spins when galaxies merge, and through the accretion of gas from their surroundings. "Extremely fast spin might be very common for large

Spin current and spin transfer torque in ferromagnet/superconductor spin valves

Science.gov (United States)

Moen, Evan; Valls, Oriol T.

2018-05-01

Using fully self-consistent methods, we study spin transport in fabricable spin valve systems consisting of two magnetic layers, a superconducting layer, and a spacer normal layer between the ferromagnets. Our methods ensure that the proper relations between spin current gradients and spin transfer torques are satisfied. We present results as a function of geometrical parameters, interfacial barrier values, misalignment angle between the ferromagnets, and bias voltage. Our main results are for the spin current and spin accumulation as functions of position within the spin valve structure. We see precession of the spin current about the exchange fields within the ferromagnets, and penetration of the spin current into the superconductor for biases greater than the critical bias, defined in the text. The spin accumulation exhibits oscillating behavior in the normal metal, with a strong dependence on the physical parameters both as to the structure and formation of the peaks. We also study the bias dependence of the spatially averaged spin transfer torque and spin accumulation. We examine the critical-bias effect of these quantities, and their dependence on the physical parameters. Our results are predictive of the outcome of future experiments, as they take into account imperfect interfaces and a realistic geometry.

Stability of a dual-spin satellite with two dampers

Science.gov (United States)

Alfriend, K. T.; Hubert, C. H.

1974-01-01

The rotational stability of a dual-spin satellite consisting of a main body and a symmetric rotor, both spinning about a common axis, is investigated. The main body is equipped with a spring-mass damper, while a partially filled viscous ring damper is mounted on the rapidly spinning rotor. The effect of fluid motion on the rotational stability of the satellite is calculated, considering the fluid as a single particle moving in a tube with viscous damping. Time constants are obtained by solving approximate equations of motion for the nutation-synchronous and the spin-synchronous modes, and the results are found to agree well with the numerical integrations of the exact equations. A limit cycle may exist for some configurations; the nutation angle tends to increase in such cases.

SANE Of Jefferson Lab: Spin Asymmetries on the Nucleon Experiment

International Nuclear Information System (INIS)

Ahmidouch, Abdellah

2011-01-01

The Spin Asymmetry on the Nucleon Experiment (SANE) at Jefferson Lab measures proton spin observables A 1 p , A 2 p and structure functions g 1 p and g 2 p over a broad range of Bjorken scaling variable x from 0.3 to 0.8, for four-momentum transfers ranging from 2.5 GeV 2 to 6.5 GeV 2 . Inclusive double spin asymmetries were measured by scattering 4.7 and 5.9-GeV longitudinally polarized electron beam off a polarized solid NH 3 target, in both parallel and near-perpendicular configuration. Scattered electrons were detected using a novel non-magnetic detector array with 194-msr acceptance. This paper presents the physics motivation for the experiment, the detector performance, and the latest status of the ongoing data analysis.

Properties of possible leptons at spin 3/2

International Nuclear Information System (INIS)

Spehler, D.

1982-01-01

Possible properties of spin 3/2 leptons are investigated. Results are presented on production cross sections of spin 3/2 leptons by means of electromagnetic interaction and weak current couplings. Characteristic angular correlations and leptons spectral distribution are indicated in weak decays. A charged spin 3/2 lepton may in particular contribute to the 3 muon events [fr

Production of spin-polarized unstable nuclei by using polarized electron capture process

International Nuclear Information System (INIS)

Shimizu, S.

1998-01-01

Measurements of emitted radiation from spin polarized nuclei are used to get information on electromagnetic moment of ground state unstable nuclei together with spin or parity state of excited states of their decayed (daughter) nuclei. These data are known to be useful for experimental investigation into the structure of unstable nuclei far from the stability line. The present study aims to establish a general method applicable to 11 Be and 16 N nuclei. To produce spin polarization, a new method in which the electron spin polarization of Rb is firstly produced by laser pumping, then the electron is transferred to the unstable nuclear beam (RNB) when they passes through the Rb vapor is proposed. Finally the polarized RNB will be implanted into superfluid helium to remain with a long spin-relaxation time. Future experimental set up for the above measurement adopted in the available radioactive nuclear beam facilities is briefly described. (Ohno, S.)

Status of IGS Ultra-Rapid Products for Real-Time Applications

Science.gov (United States)

Ray, J.; Griffiths, J.

2008-12-01

Since November 2000 the International GNSS Service (IGS) has produced Ultra-rapid (IGU) products for near real-time and real-time applications. They include GPS orbits, satellite clocks, and Earth rotation parameters for a sliding 48-hr period. The first day of each update is based on the most recent GPS observational data from the IGS hourly tracking network. At the time of release, these observed products have an initial latency of 3 hr. The second day of each update consists of predictions. So the predictions between about 3 and 9 hr into the second half are relevant for true real-time uses. Originally updated twice daily, the IGU products since April 2004 have been issued four times per day, at 3, 9, 15, and 21 UTC. Up to seven Analysis Centers (ACs) contribute to the IGU combinations: Astronomical Institute of the University of Berne (AIUB), European Space Operations Center (ESOC), Geodetic Observatory Pecny (GOP), GeoForschungsZentrum (GFZ) Potsdam, Natural Resources Canada (NRC), Scripps Insitution of Oceanography (SIO), U.S. Naval Observatory (USNO). This redundancy affords a high measure of reliability and enhanced orbit accuracy. IGU orbit precision has improved markedly since late 2007. This is due to a combination of factors: decommissioning of the old, poorly behaved PRN29 in October 2007; upgraded procedures implemented by GOP around the same time, by SIO in spring 2008, and by USNO in June 2008; better handling of maneuvered satellites at the combination level starting June 2008; and stricter AC rejection criteria since July 2008. As a consequence, the weighted 1D RMS residual of the IGU orbit predictions over their first 6 hr is currently about 20 to 30 mm (after a Helmert transformation) compared to the IGS Rapid orbits, averaged over the constellation. The median residual is about 15 to 20 mm. When extended to the full 24 hr prediction period, the IGU orbit errors approximately double. Systematic rotational offsets are probably more important than

Recent trends in rapid dereplication of natural product extracts：an update

Institute of Scientific and Technical Information of China (English)

Fikre Mammo; Milkyas Endale

2015-01-01

Natural products are the prominent sources of drugs to combat various infectious diseases. The rapid progress of multi-resistance and pan-resistant pathogens to various medicines represents today a major challenge. The search for novel natural products requires a quick and efficient approach to distinguish novel compounds from the known ones, a process called dereplication. Dereplication strategy is generic and time-saving, avoids isolation/purification of known compounds, enables an efficient liquid chromatography peak annotation of most of the studied compounds and can be well adapted for plant chemotaxonomy, phytochemical screening and metabolite profiling. In this review, recent developments of hyphenated techniques towards dereplication of active compounds, chemotaxonomy, metabolite profiling and rapid detection of novel compounds in medicinal plant extracts are presented.

Optically tunable spin transport on the surface of a topological insulator

International Nuclear Information System (INIS)

Yudin, D; Shelykh, I A; Kibis, O V

2016-01-01

The emerging field of spinoptronics has a potential to supersede the functionality of modern electronics, while a proper description of strong light–matter coupling pose the most intriguing questions from both fundamental scientific and technological perspectives. In this paper we address a highly relevant issue for such a development. We theoretically explore spin dynamics on the surface of a 3D topological insulator (TI) irradiated with an off-resonant high-frequency electromagnetic wave. The strong coupling between electrons and the electromagnetic wave drastically modifies the spin properties of TI. The effects of irradiation are shown to result in anisotropy of electron energy spectrum near the Dirac point and suppression of spin current and are investigated in detail in this work. (paper)

Statistical model of hadrons multiple production in space of total angular momentum and isotopic spin

International Nuclear Information System (INIS)

Gridneva, S.A.; Rus'kin, V.I.

1980-01-01

Basic features of the statistical model of multiple hadron production based on microcanonical distribution and taking into account the laws of conservation of total angular momentum, isotopic spin, p-, G-, C-eveness and Bose-Einstein statistics requirements are given. The model predictions are compared with experimental data on anti NN annihilation at rest and e + e - annihilation in hadrons at annihilation total energy from 2 to 3 GeV [ru

Measurement of gluon polarization through spin asymmetry in the production of charmed mesons

International Nuclear Information System (INIS)

Panebianco, St.

2005-09-01

The main aim of the COMPASS experiment is the measurement of the gluon polarization in the nucleon, which can be accessed by the spin asymmetry in the scattering of a polarized muon beam on a polarized nucleon target. The process sensitive to the gluon polarization is the photon-gluon fusion, which can be tagged in the cleanest way by looking at the production of D 0 mesons. At COMPASS, D 0 mesons are reconstructed from the invariant mass of their decay products. However, it is a rare process, dominated by a large combinatorial background. This thesis presents some studies devoted to the improvement of the charmed mesons reconstruction. The measurement of the efficiency and the space resolution of the 3 drift chamber stations of the COMPASS spectrometer is a necessary step in understanding the performances of the reconstruction of particle trajectories. The hadron identification, which is fundamental in the reconstruction of charmed meson decay, is performed by a RICH detector. A statistical treatment of signal and background, together with an upgrade project to replace the present front-end electronics, have been developed in order to improve the particle identification performances. The second part of this work concerns the spin asymmetry measurement, which requires the application of event selection criteria in order to minimize the noise over signal ratio in the D 0 invariant mass, and the development of event-weighting methods to reduce the statistical error. This work presents a preliminary result, based on 2002-2004 statistics, which is the ΔG/G measurement from open charm production. Although the error bars are large, the measured gluon polarization is compatible with zero. Given the present accuracy, this result is compatible with the existing direct measurements from other channels. However, it does not allow to distinguish between different theoretical models. (author)

Linear spin waves in a trapped Bose gas

International Nuclear Information System (INIS)

Nikuni, T.; Williams, J.E.; Clark, C.W.

2002-01-01

An ultracold Bose gas of two-level atoms can be thought of as a spin-1/2 Bose gas. It supports spin-wave collective modes due to the exchange mean field. Such collective spin oscillations have been observed in recent experiments at JILA with 87 Rb atoms confined in a harmonic trap. We present a theory of the spin-wave collective modes based on the moment method for trapped gases. In the collisionless and hydrodynamic limits, we derive analytic expressions for the frequencies and damping rates of modes with dipole and quadrupole symmetry. We find that the frequency for a given mode is given by a temperature-independent function of the peak density n, and falls off as 1/n. We also find that, to a very good approximation, excitations in the radial and axial directions are decoupled. We compare our model to the numerical integration of a one-dimensional version of the kinetic equation and find very good qualitative agreement. The damping rates, however, show the largest deviation for intermediate densities, where one expects Landau damping--which is unaccounted for in our moment approach--to play a significant role

Quantum ring with the Rashba spin-orbit interaction in the regime of strong light-matter coupling

Science.gov (United States)

Kozin, V. K.; Iorsh, I. V.; Kibis, O. V.; Shelykh, I. A.

2018-04-01

We developed the theory of electronic properties of semiconductor quantum rings with the Rashba spin-orbit interaction irradiated by an off-resonant high-frequency electromagnetic field (dressing field). Within the Floquet theory of periodically driven quantum systems, it is demonstrated that the dressing field drastically modifies all electronic characteristics of the rings, including spin-orbit coupling, effective electron mass, and optical response. In particular, the present effect paves the way to controlling the spin polarization of electrons with light in prospective ring-shaped spintronic devices.

Spin effects in strong-field laser-electron interactions

International Nuclear Information System (INIS)

Ahrens, S; Bauke, H; Müller, T-O; Villalba-Chávez, S; Müller, C

2013-01-01

The electron spin degree of freedom can play a significant role in relativistic scattering processes involving intense laser fields. In this contribution we discuss the influence of the electron spin on (i) Kapitza-Dirac scattering in an x-ray laser field of high intensity, (ii) photo-induced electron-positron pair production in a strong laser wave and (iii) multiphoton electron-positron pair production on an atomic nucleus. We show that in all cases under consideration the electron spin can have a characteristic impact on the process properties and their total probabilities. To this end, spin-resolved calculations based on the Dirac equation in the presence of an intense laser field are performed. The predictions from Dirac theory are also compared with the corresponding results from the Klein-Gordon equation.

Rapid screening of N-oxides of chemical warfare agents degradation products by ESI-tandem mass spectrometry.

Science.gov (United States)

Sridhar, L; Karthikraj, R; Lakshmi, V V S; Raju, N Prasada; Prabhakar, S

2014-08-01

Rapid detection and identification of chemical warfare agents and related precursors/degradation products in various environmental matrices is of paramount importance for verification of standards set by the chemical weapons convention (CWC). Nitrogen mustards, N,N-dialkylaminoethyl-2-chlorides, N,N-dialkylaminoethanols, N-alkyldiethanolamines, and triethanolamine, which are listed CWC scheduled chemicals, are prone to undergo N-oxidation in environmental matrices or during decontamination process. Thus, screening of the oxidized products of these compounds is also an important task in the verification process because the presence of these products reveals alleged use of nitrogen mustards or precursors of VX compounds. The N-oxides of aminoethanols and aminoethylchlorides easily produce [M + H](+) ions under electrospray ionization conditions, and their collision-induced dissociation spectra include a specific neutral loss of 48 u (OH + CH2OH) and 66 u (OH + CH2Cl), respectively. Based on this specific fragmentation, a rapid screening method was developed for screening of the N-oxides by applying neutral loss scan technique. The method was validated and the applicability of the method was demonstrated by analyzing positive and negative samples. The method was useful in the detection of N-oxides of aminoethanols and aminoethylchlorides in environmental matrices at trace levels (LOD, up to 500 ppb), even in the presence of complex masking agents, without the use of time-consuming sample preparation methods and chromatographic steps. This method is advantageous for the off-site verification program and also for participation in official proficiency tests conducted by the Organization for the Prohibition of Chemical Weapons (OPCW), the Netherlands. The structure of N-oxides can be confirmed by the MS/MS experiments on the detected peaks. A liquid chromatography-mass spectrometry (LC-MS) method was developed for the separation of isomeric N-oxides of aminoethanols and

Characterizing Coastal Ecosystem Service Trade-offs with Future Urban Development in a Tropical City.

Science.gov (United States)

Richards, Daniel R; Friess, Daniel A

2017-11-01

With rapid urbanization in the coastal zone and increasing habitat losses, it is imperative to understand how urban development affects coastal biodiversity and ecosystem service provision. Furthermore, it is important to understand how habitat fragments can best be incorporated into broader land use planning and coastal management, in order to maximize the environmental benefits they provide. In this study, we characterized the trade-offs between (a) urban development and individual mangrove environmental indicators (habitat quality and ecosystem services), and (b) between different environmental indicators in the tropical nation of Singapore. A range of biological, biophysical, and cultural indicators, including carbon, charcoal production, support for offshore fisheries, recreation, and habitat quality for a threatened species were quantified using field-based, remote sensing, and expert survey methods. The shape of the trade-off Pareto frontiers was analyzed to assess the sensitivity of environmental indicators for development. When traded off individually with urban development, four out of five environmental indicators were insensitive to development, meaning that relatively minor degradation of the indicator occurred while development was below a certain threshold, although indicator loss accelerated once this threshold was reached. Most of the pairwise relationships between the five environmental indicators were synergistic; only carbon storage and charcoal production, and charcoal production and recreational accessibility showed trade-offs. Trade-off analysis and land use optimization using Pareto frontiers could be a useful decision-support tool for understanding how changes in land use and coastal management will impact the ability of ecosystems to provide environmental benefits.

Characterizing Coastal Ecosystem Service Trade-offs with Future Urban Development in a Tropical City

Science.gov (United States)

Richards, Daniel R.; Friess, Daniel A.

2017-11-01

With rapid urbanization in the coastal zone and increasing habitat losses, it is imperative to understand how urban development affects coastal biodiversity and ecosystem service provision. Furthermore, it is important to understand how habitat fragments can best be incorporated into broader land use planning and coastal management, in order to maximize the environmental benefits they provide. In this study, we characterized the trade-offs between (a) urban development and individual mangrove environmental indicators (habitat quality and ecosystem services), and (b) between different environmental indicators in the tropical nation of Singapore. A range of biological, biophysical, and cultural indicators, including carbon, charcoal production, support for offshore fisheries, recreation, and habitat quality for a threatened species were quantified using field-based, remote sensing, and expert survey methods. The shape of the trade-off Pareto frontiers was analyzed to assess the sensitivity of environmental indicators for development. When traded off individually with urban development, four out of five environmental indicators were insensitive to development, meaning that relatively minor degradation of the indicator occurred while development was below a certain threshold, although indicator loss accelerated once this threshold was reached. Most of the pairwise relationships between the five environmental indicators were synergistic; only carbon storage and charcoal production, and charcoal production and recreational accessibility showed trade-offs. Trade-off analysis and land use optimization using Pareto frontiers could be a useful decision-support tool for understanding how changes in land use and coastal management will impact the ability of ecosystems to provide environmental benefits.

Next-to-leading order electroweak corrections to off-shell WWW production at the LHC arXiv

CERN Document Server

Schönherr, Marek

Triboson processes allow for a measurement of the triple and quartic couplings of the Standard Model gauge bosons, which can be used to constrain anomalous gauge couplings. In this paper we calculate the next-to-leading order electroweak corrections to fully off-shell $W^-W^+W^+$ production, namely the production of a $\\ell_1^-\\ell_2^+\\ell_3^+\\bar{\

Measurement of gluon polarization through spin asymmetry in the production of charmed mesons; Mesure de la polarisation des gluons par l'asymetrie de spin dans la production de mesons charmes

Energy Technology Data Exchange (ETDEWEB)

Panebianco, St

2005-09-15

The main aim of the COMPASS experiment is the measurement of the gluon polarization in the nucleon, which can be accessed by the spin asymmetry in the scattering of a polarized muon beam on a polarized nucleon target. The process sensitive to the gluon polarization is the photon-gluon fusion, which can be tagged in the cleanest way by looking at the production of D{sup 0} mesons. At COMPASS, D{sup 0} mesons are reconstructed from the invariant mass of their decay products. However, it is a rare process, dominated by a large combinatorial background. This thesis presents some studies devoted to the improvement of the charmed mesons reconstruction. The measurement of the efficiency and the space resolution of the 3 drift chamber stations of the COMPASS spectrometer is a necessary step in understanding the performances of the reconstruction of particle trajectories. The hadron identification, which is fundamental in the reconstruction of charmed meson decay, is performed by a RICH detector. A statistical treatment of signal and background, together with an upgrade project to replace the present front-end electronics, have been developed in order to improve the particle identification performances. The second part of this work concerns the spin asymmetry measurement, which requires the application of event selection criteria in order to minimize the noise over signal ratio in the D{sup 0} invariant mass, and the development of event-weighting methods to reduce the statistical error. This work presents a preliminary result, based on 2002-2004 statistics, which is the {delta}G/G measurement from open charm production. Although the error bars are large, the measured gluon polarization is compatible with zero. Given the present accuracy, this result is compatible with the existing direct measurements from other channels. However, it does not allow to distinguish between different theoretical models. (author)

Spin analysis of supersymmetric particles

International Nuclear Information System (INIS)

Choi, S.Y.; Martyn, H.U.

2006-12-01

The spin of supersymmetric particles can be determined at e + e - colliders unambiguously. This is demonstrated for a characteristic set of non-colored supersymmetric particles -- smuons, selectrons, and charginos/neutralinos. The analysis is based on the threshold behavior of the excitation curves for pair production in e + e - collisions, the angular distribution in the production process and decay angular distributions. In the first step we present the observables in the helicity formalism for the supersymmetric particles. Subsequently we confront the results with corresponding analyses of Kaluza-Klein particles in theories of universal extra space dimensions which behave distinctly different from supersymmetric theories. It is shown in the third step that a set of observables can be designed which signal the spin of supersymmetric particles unambiguously without any model assumptions. Finally in the fourth step it is demonstrated that the determination of the spin of supersymmetric particles can be performed experimentally in practice at an e + e - collider. (orig.)

Diel production and microheterotrophic utilization of dissolved free amino acids in waters off southern California

International Nuclear Information System (INIS)

Carlucci, A.F.; Craven, D.B.; Henrichs, S.M.

1984-01-01

Diel patterns of dissolved free amino acid (DFAA) concentration and microheterotrophic utilization were examined in the spring and fall of 1981 in euphotic waters from the base of the mixed layer off the southern California coast. The average depths of the isotherms sampled were 19.2 m for spring and 9.0 for fall. Total DFAA levels were generally higher in the spring than in the fall, 18 to 66 nM and 14 to 20 nM, respectively. Two daily concentration maxima and minima were observed for total DFAAs as well as for most individual DFAAs. Maxima were usually measured in the mid-dark period and in the early afternoon; minima were typically observed in early morning and late afternoon. Bacterial cell numbers reached maximal values near midnight in both seasons. The increases coincided with one of the total DFAA maxima. The second total DFAA maximum occurred in early to midafternoon, during the time of maximum photosynthetic carbon production and rapid dissolved amino acid utilization. Microbial metabolism (incorporation plus respiration) of selected 3 H-amino acids was 2.7 to 4.1 times greater during the daylight hours. DFAA turnover times, based on these metabolic measurements, ranged between 11 and 36 h for the amino acids tested, and rates were 1.7 to 3.7 times faster in the daylight hours than at night. DFAA distributions were related to primary production and chlorophyll a concentrations. Amino acids were estimated to represent 9 to 45% of the total phytoplankton exudate. Microheterotrophic utilization or production of total protein amino acids was estimated as 3.6 μg of C liter -1 day -1 in spring and 1.9 μg of C liter -1 day -1 in the fall. Assimilation efficiency for dissolved amino acids averaged 65% for marine microheterotrophs

Muon spin relaxation measurements of the fluctuation modes in spin-glass AgNm

Energy Technology Data Exchange (ETDEWEB)

Heffner, R.H.; Leon, M.; Schillaci, M.E.; MacLaughlin, D.E.; Dodds, S.A.

1983-01-01

Recently reported zero-field ..mu..SR measurements below the spin-glass transition temperature in AgMn (1.6 at%) show a temperature dependent inhomogeneous width. The authors discuss these data in terms of a model in which the local field undergoes limited-amplitude fluctuations. The authors find that both very slow (approx. = 0.3 ..mu..s/sup -1/) and rapid (approx. = 3000 ..mu..s/sup -1/) fluctuations are required. 10 references, 1 figure, 1 table.

Asymmetric core collapse of rapidly rotating massive star

Science.gov (United States)

Gilkis, Avishai

2018-02-01

Non-axisymmetric features are found in the core collapse of a rapidly rotating massive star, which might have important implications for magnetic field amplification and production of a bipolar outflow that can explode the star, as well as for r-process nucleosynthesis and natal kicks. The collapse of an evolved rapidly rotating MZAMS = 54 M⊙ star is followed in three-dimensional hydrodynamic simulations using the FLASH code with neutrino leakage. A rotating proto-neutron star (PNS) forms with a non-zero linear velocity. This can contribute to the natal kick of the remnant compact object. The PNS is surrounded by a turbulent medium, where high shearing is likely to amplify magnetic fields, which in turn can drive a bipolar outflow. Neutron-rich material in the PNS vicinity might induce strong r-process nucleosynthesis. The rapidly rotating PNS possesses a rotational energy of E_rot ≳ 10^{52} erg. Magnetar formation proceeding in a similar fashion will be able to deposit a portion of this energy later on in the supernova ejecta through a spin-down mechanism. These processes can be important for rare supernovae generated by rapidly rotating progenitors, even though a complete explosion is not simulated in the present study.

Spin current evolution in the separated spin-up and spin-down quantum hydrodynamics

International Nuclear Information System (INIS)

Trukhanova, Mariya Iv.

2015-01-01

We have developed a method of quantum hydrodynamics (QHD) that describes particles with spin-up and with spin-down in separate. We have derived the equation of the spin current evolution as a part of the set of the quantum hydrodynamics equations that treat particles with different projection of spin on the preferable direction as two different species. We have studied orthogonal propagation of waves in the external magnetic field and determined the contribution of quantum corrections due to the Bohm potential and to magnetization energy of particles with different projections of spin in the spin-current wave dispersion. We have analyzed the limits of weak and strong magnetic fields. - Highlights: • We derive the spin current equation for particles with different projection of spin. • We predict the contribution of Bohm potential to the dynamics of spin current. • We derive the spin-current wave in the system of spin-polarized particles. • We study the propagation of spin-acoustic wave in magnetized dielectrics.

Muonium spin exchange in spin-polarized media: Spin-flip and -nonflip collisions

International Nuclear Information System (INIS)

Senba, M.

1994-01-01

The transverse relaxation of the muon spin in muonium due to electron spin exchange with a polarized spin-1/2 medium is investigated. Stochastic calculations, which assume that spin exchange is a Poisson process, are carried out for the case where the electron spin polarization of the medium is on the same axis as the applied field. Two precession signals of muonium observed in intermediate fields (B>30 G) are shown to have different relaxation rates which depend on the polarization of the medium. Furthermore, the precession frequencies are shifted by an amount which depends on the spin-nonflip rate. From the two relaxation rates and the frequency shift in intermediate fields, one can determine (i) the encounter rate of muonium and the paramagnetic species, (ii) the polarization of the medium, and most importantly (iii) the quantum-mechanical phase shift (and its sign) associated with the potential energy difference between electron singlet and triplet encounters. Effects of spin-nonflip collisions on spin dynamics are discussed for non-Poisson as well as Poisson processes. In unpolarized media, the time evolution of the muon spin in muonium is not influenced by spin-nonflip collisions, if the collision process is Poissonian. This seemingly obvious statement is not true anymore in non-Poissonian processes, i.e., it is necessary to specify both spin-flip and spin-nonflip rates to fully characterize spin dynamics

Neutralino spin measurement with ATLAS

CERN Document Server

Ventura, A

2007-01-01

One of the goals of the ATLAS experiment at the LHC is to search for evidence of Supersymmetry (SUSY) signals and to measure, if discovered, the main properties of the new particles, like the spin. Left-handed squark cascade decay to second lightest neutralino which further decays to slepton represents a good opportunity for SUSY particles' spin measurement. The observability of charge asymmetries in invariant mass distributions of some final products is investigated to prove that neutralino spin is 1/2. The criteria used to select signal events and to reject background are described, together with the applied cut efficiencies. Results on charge asymmetry are then shown and discussed.

[The use of medicinal products "off-label use" in the pediatric population--the border risk, or reasonable diligence?].

Science.gov (United States)

Zajdel, Justyna

2011-01-01

Any medicinal product marketed in the country has its registration, under which are strictly defined indications and the extent to which a product can be used. It is of significance that the use of the product which is registered in the given range produces an effect similar to or identical to that effect, which is obtained after applying the product having a registration in a given indication. Relied on to justify the use of a medicinal product or medical product "off-label use" in Poland, there is also the fact that the same product has a registration in a particular indication in another EU member state or outside the Community. It is worth noting that the medicinal product may be used in therapeutic management of omitting or reducing the principles resulting from the SPC. However, this applies only to cases where the use of the medicinal product "off-label use" dictated by the necessity of saving life or health of the patient, and the previous ways and methods of treatment with the use of registered medicines have proved ineffective or insufficient to achieve the desired therapeutic effect.

Entanglement and quantum phase transitions in matrix-product spin-1 chains

International Nuclear Information System (INIS)

Alipour, S.; Karimipour, V.; Memarzadeh, L.

2007-01-01

We consider a one-parameter family of matrix-product states of spin-1 particles on a periodic chain and study in detail the entanglement properties of such a state. In particular, we calculate exactly the entanglement of one site with the rest of the chain, and the entanglement of two distant sites with each other, and show that the derivative of both these properties diverge when the parameter g of the states passes through a critical point. Such a point can be called a point of quantum phase transition, since at this point the character of the matrix-product state, which is the ground state of a Hamiltonian, changes discontinuously. We also study the finite size effects and show how the entanglement depends on the size of the chain. This later part is relevant to the field of quantum computation where the problem of initial state preparation in finite arrays of qubits or qutrits is important. It is also shown that the entanglement of two sites have scaling behavior near the critical point

On the rapid melt quenching

International Nuclear Information System (INIS)

Usatyuk, I.I.; Novokhatskij, I.A.; Kaverin, Yu.F.

1994-01-01

Specific features of instrumentation of traditionally employed method of melt spinning (rapid quenching), its disadvantages being discussed, were analyzed. The necessity of the method upgrading as applied to the problems of studying fine structure of molten metals and glasses was substantiated. The principle flowsheet of experimental facility for extremely rapid quenching of the melts of metals is described, specificity of its original functional units being considered. The sequence and character of all the principal stages of the method developed were discussed. 18 refs.; 3 figs

Neutron spin quantum precession using multilayer spin splitters and a phase-spin echo interferometer

International Nuclear Information System (INIS)

Ebisawa, Toru; Tasaki, Seiji; Kawai, Takeshi; Hino, Masahiro; Akiyoshi, Tsunekazu; Achiwa, Norio; Otake, Yoshie; Funahashi, Haruhiko.

1996-01-01

Neutron spin quantum precession by multilayer spin splitter has been demonstrated using a new spin interferometer. The multilayer spin splitter consists of a magnetic multilayer mirror on top, followed by a gap layer and a non magnetic multilayer mirror which are evaporated on a silicon substrate. Using the multilayer spin splitter, a polarized neutron wave in a magnetic field perpendicular to the polarization is split into two spin eigenstates with a phase shift in the direction of the magnetic field. The spin quantum precession is equal to the phase shift, which depends on the effective thickness of the gap layer. The demonstration experiments verify the multilayer spin splitter as a neutron spin precession device as well as the coherent superposition principle of the two spin eigenstates. We have developed a new phase-spin echo interferometer using the multilayer spin splitters. We present successful performance tests of the multilayer spin splitter and the phase-spin echo interferometer. (author)

Photoinduced quantum spin and valley Hall effects, and orbital magnetization in monolayer MoS2

KAUST Repository

Tahir, M.

2014-09-22

We theoretically demonstrate that 100% valley-polarized transport in monolayers of MoS2 and other group-VI dichalcogenides can be obtained using off-resonant circularly polarized light. By tuning the intensity of the off-resonant light the intrinsic band gap in one valley is reduced, while it is enhanced in the other valley, enabling single valley quantum transport. As a consequence, we predict (i) enhancement of the longitudinal electrical conductivity, accompanied by an increase in the spin polarization of the flowing electrons, (ii) enhancement of the intrinsic spin Hall effect, together with a reduction of the intrinsic valley Hall effect, and (iii) enhancement of the orbital magnetic moment and orbital magnetization. These mechanisms provide appealing opportunities to the design of nanoelectronics based on dichalcogenides.

Photoinduced quantum spin and valley Hall effects, and orbital magnetization in monolayer MoS2

KAUST Repository

Tahir, M.; Manchon, Aurelien; Schwingenschlö gl, Udo

2014-01-01

We theoretically demonstrate that 100% valley-polarized transport in monolayers of MoS2 and other group-VI dichalcogenides can be obtained using off-resonant circularly polarized light. By tuning the intensity of the off-resonant light the intrinsic band gap in one valley is reduced, while it is enhanced in the other valley, enabling single valley quantum transport. As a consequence, we predict (i) enhancement of the longitudinal electrical conductivity, accompanied by an increase in the spin polarization of the flowing electrons, (ii) enhancement of the intrinsic spin Hall effect, together with a reduction of the intrinsic valley Hall effect, and (iii) enhancement of the orbital magnetic moment and orbital magnetization. These mechanisms provide appealing opportunities to the design of nanoelectronics based on dichalcogenides.

Nuclear Dependence of the Transverse-Single-Spin Asymmetry for Forward Neutron Production in Polarized p +A Collisions at √{sN N}=200 GeV

Science.gov (United States)

Aidala, C.; Akiba, Y.; Alfred, M.; Andrieux, V.; Aoki, K.; Apadula, N.; Asano, H.; Ayuso, C.; Azmoun, B.; Babintsev, V.; Bagoly, A.; Bandara, N. S.; Barish, K. N.; Bathe, S.; Bazilevsky, A.; Beaumier, M.; Belmont, R.; Berdnikov, A.; Berdnikov, Y.; Blau, D. S.; Boer, M.; Bok, J. S.; Brooks, M. L.; Bryslawskyj, J.; Bumazhnov, V.; Butler, C.; Campbell, S.; Canoa Roman, V.; Cervantes, R.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Citron, Z.; Connors, M.; Cronin, N.; Csanád, M.; Csörgő, T.; Danley, T. W.; Daugherity, M. S.; David, G.; Deblasio, K.; Dehmelt, K.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dion, A.; Dixit, D.; Do, J. H.; Drees, A.; Drees, K. A.; Dumancic, M.; Durham, J. M.; Durum, A.; Elder, T.; Enokizono, A.; En'yo, H.; Esumi, S.; Fadem, B.; Fan, W.; Feege, N.; Fields, D. E.; Finger, M.; Finger, M.; Fokin, S. L.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fukuda, Y.; Gal, C.; Gallus, P.; Garg, P.; Ge, H.; Giordano, F.; Goto, Y.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gunji, T.; Guragain, H.; Hachiya, T.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamilton, H. F.; Han, S. Y.; Hanks, J.; Hasegawa, S.; Haseler, T. O. S.; He, X.; Hemmick, T. K.; Hill, J. C.; Hill, K.; Hollis, R. S.; Homma, K.; Hong, B.; Hoshino, T.; Hotvedt, N.; Huang, J.; Huang, S.; Imai, K.; Imrek, J.; Inaba, M.; Iordanova, A.; Isenhower, D.; Ito, Y.; Ivanishchev, D.; Jacak, B. V.; Jezghani, M.; Ji, Z.; Jiang, X.; Johnson, B. M.; Jorjadze, V.; Jouan, D.; Jumper, D. S.; Kang, J. H.; Kapukchyan, D.; Karthas, S.; Kawall, D.; Kazantsev, A. V.; Khachatryan, V.; Khanzadeev, A.; Kim, C.; Kim, D. J.; Kim, E.-J.; Kim, M.; Kim, M. H.; Kincses, D.; Kistenev, E.; Klatsky, J.; Kline, P.; Koblesky, T.; Kotov, D.; Kudo, S.; Kurita, K.; Kwon, Y.; Lajoie, J. G.; Lallow, E. O.; Lebedev, A.; Lee, S.; Leitch, M. J.; Leung, Y. H.; Lewis, N. A.; Li, X.; Lim, S. H.; Liu, L. D.; Liu, M. X.; Loggins, V.-R.; Lökös, S.; Lovasz, K.; Lynch, D.; Majoros, T.; Makdisi, Y. I.; Makek, M.; Malaev, M.; Manko, V. I.; Mannel, E.; Masuda, H.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Mendoza, M.; Metzger, W. J.; Mignerey, A. C.; Mihalik, D. E.; Milov, A.; Mishra, D. K.; Mitchell, J. T.; Mitsuka, G.; Miyasaka, S.; Mizuno, S.; Montuenga, P.; Moon, T.; Morrison, D. P.; Morrow, S. I. M.; Murakami, T.; Murata, J.; Nagai, K.; Nagashima, K.; Nagashima, T.; Nagle, J. L.; Nagy, M. I.; Nakagawa, I.; Nakagomi, H.; Nakano, K.; Nattrass, C.; Niida, T.; Nouicer, R.; Novák, T.; Novitzky, N.; Novotny, R.; Nyanin, A. S.; O'Brien, E.; Ogilvie, C. A.; Orjuela Koop, J. D.; Osborn, J. D.; Oskarsson, A.; Ottino, G. J.; Ozawa, K.; Pantuev, V.; Papavassiliou, V.; Park, J. S.; Park, S.; Pate, S. F.; Patel, M.; Peng, W.; Perepelitsa, D. V.; Perera, G. D. N.; Peressounko, D. Yu.; Perezlara, C. E.; Perry, J.; Petti, R.; Phipps, M.; Pinkenburg, C.; Pisani, R. P.; Pun, A.; Purschke, M. L.; Radzevich, P. V.; Read, K. F.; Reynolds, D.; Riabov, V.; Riabov, Y.; Richford, D.; Rinn, T.; Rolnick, S. D.; Rosati, M.; Rowan, Z.; Runchey, J.; Safonov, A. S.; Sakaguchi, T.; Sako, H.; Samsonov, V.; Sarsour, M.; Sato, K.; Sato, S.; Schaefer, B.; Schmoll, B. K.; Sedgwick, K.; Seidl, R.; Sen, A.; Seto, R.; Sexton, A.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shioya, T.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Singh, B. K.; Singh, C. P.; Singh, V.; Skoby, M. J.; Slunečka, M.; Smith, K. L.; Snowball, M.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Stankus, P. W.; Stoll, S. P.; Sugitate, T.; Sukhanov, A.; Sumita, T.; Sun, J.; Syed, S.; Sziklai, J.; Takeda, A.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tarnai, G.; Tieulent, R.; Timilsina, A.; Todoroki, T.; Tomášek, M.; Towell, C. L.; Towell, R. S.; Tserruya, I.; Ueda, Y.; Ujvari, B.; van Hecke, H. W.; Vazquez-Carson, S.; Velkovska, J.; Virius, M.; Vrba, V.; Vukman, N.; Wang, X. R.; Wang, Z.; Watanabe, Y.; Watanabe, Y. S.; Wong, C. P.; Woody, C. L.; Xu, C.; Xu, Q.; Xue, L.; Yalcin, S.; Yamaguchi, Y. L.; Yamamoto, H.; Yanovich, A.; Yin, P.; Yoo, J. H.; Yoon, I.; Yu, H.; Yushmanov, I. E.; Zajc, W. A.; Zelenski, A.; Zharko, S.; Zou, L.; Phenix Collaboration

2018-01-01

During 2015, the Relativistic Heavy Ion Collider (RHIC) provided collisions of transversely polarized protons with Au and Al nuclei for the first time, enabling the exploration of transverse-single-spin asymmetries with heavy nuclei. Large single-spin asymmetries in very forward neutron production have been previously observed in transversely polarized p +p collisions at RHIC, and the existing theoretical framework that was successful in describing the single-spin asymmetry in p +p collisions predicts only a moderate atomic-mass-number (A ) dependence. In contrast, the asymmetries observed at RHIC in p +A collisions showed a surprisingly strong A dependence in inclusive forward neutron production. The observed asymmetry in p +Al collisions is much smaller, while the asymmetry in p +Au collisions is a factor of 3 larger in absolute value and of opposite sign. The interplay of different neutron production mechanisms is discussed as a possible explanation of the observed A dependence.

RHIC spin program

International Nuclear Information System (INIS)

Bunce, G.

1995-01-01

Colliding beams of high energy polarized protons at RHIC is an excellent way to probe the polarization of gluons, u and d quarks in a polarized proton. RHIC is the Relativistic Heavy Ion Collider being built now at Brookhaven in the ISABELLE tunnel. It is designed to collide gold ions on gold ions at 100 GeV/nucleon. Its goal is to discover the quark-gluon plasma, and the first collisions are expected in March, 1999. RHIC will also make an ideal polarized proton collider with high luminosity and 250 GeV x 250 GeV collisions. The RHIC spin physics program is: (1) Use well-understood perturbative QCD probes to study non-perturbative confining dynamics in QCD. We will measure - gluon and sea quark polarization in a polarized proton, polarization of quarks in a transversely polarized proton. (2) Look for additional surprises using the first high energy polarized proton collider. We will - look for the expected maximal parity violation in W and Z boson production, - search for parity violation in other processes, - test parton models with spin. This lecture is organized around a few of the key ideas: Siberian Snakes--What are they? High energy proton-proton collisions are scatters of quarks and leptons, at high x, a polarized proton beam is a beam of polarized u quarks, quark and gluon collisions are very sensitive to spin. We will discuss two reactions: how direct photon production measures gluon polarization, and how W + boson production measures u and d quark polarization

RHIC spin program

Energy Technology Data Exchange (ETDEWEB)

Bunce, G.

1995-12-31

Colliding beams of high energy polarized protons at RHIC is an excellent way to probe the polarization of gluons, u and d quarks in a polarized proton. RHIC is the Relativistic Heavy Ion Collider being built now at Brookhaven in the ISABELLE tunnel. It is designed to collide gold ions on gold ions at 100 GeV/nucleon. Its goal is to discover the quark-gluon plasma, and the first collisions are expected in March, 1999. RHIC will also make an ideal polarized proton collider with high luminosity and 250 GeV x 250 GeV collisions. The RHIC spin physics program is: (1) Use well-understood perturbative QCD probes to study non-perturbative confining dynamics in QCD. We will measure - gluon and sea quark polarization in a polarized proton, polarization of quarks in a transversely polarized proton. (2) Look for additional surprises using the first high energy polarized proton collider. We will - look for the expected maximal parity violation in W and Z boson production, - search for parity violation in other processes, - test parton models with spin. This lecture is organized around a few of the key ideas: Siberian Snakes--What are they? High energy proton-proton collisions are scatters of quarks and leptons, at high x, a polarized proton beam is a beam of polarized u quarks, quark and gluon collisions are very sensitive to spin. We will discuss two reactions: how direct photon production measures gluon polarization, and how W{sup +} boson production measures u and d quark polarization.

Cast Off expansion plan by rapid improvement through Optimization tool design, Tool Parameters and using Six Sigma’s ECRS Technique

Science.gov (United States)

Gopalakrishnan, T.; Saravanan, R.

2017-03-01

Powerful management concepts step-up the quality of the product, time saving in producing the product thereby increase the production rate, improves tools and techniques, work culture, work place and employee motivation and morale. In this paper discussed about the case study of optimizing the tool design, tool parameters to cast off expansion plan according ECRS technique. The proposed designs and optimal tool parameters yielded best results and meet the customer demand without expansion plan. Hence the work yielded huge savings of money (direct and indirect cost), time and improved the motivation and more of employees significantly.

Spin drift and spin diffusion currents in semiconductors

Energy Technology Data Exchange (ETDEWEB)

Idrish Miah, M [Nanoscale Science and Technology Centre and School of Biomolecular and Physical Sciences, Griffith University, Nathan, Brisbane, QLD 4111 (Australia)], E-mail: m.miah@griffith.edu.au

2008-09-15

On the basis of a spin drift-diffusion model, we show how the spin current is composed and find that spin drift and spin diffusion contribute additively to the spin current, where the spin diffusion current decreases with electric field while the spin drift current increases, demonstrating that the extension of the spin diffusion length by a strong field does not result in a significant increase in spin current in semiconductors owing to the competing effect of the electric field on diffusion. We also find that there is a spin drift-diffusion crossover field for a process in which the drift and diffusion contribute equally to the spin current, which suggests a possible method of identifying whether the process for a given electric field is in the spin drift or spin diffusion regime. Spin drift-diffusion crossover fields for GaAs are calculated and are found to be quite small. We derive the relations between intrinsic spin diffusion length and the spin drift-diffusion crossover field of a semiconductor for different electron statistical regimes. The findings resulting from this investigation might be important for semiconductor spintronics.

Spin drift and spin diffusion currents in semiconductors

Directory of Open Access Journals (Sweden)

M Idrish Miah

2008-01-01

Full Text Available On the basis of a spin drift-diffusion model, we show how the spin current is composed and find that spin drift and spin diffusion contribute additively to the spin current, where the spin diffusion current decreases with electric field while the spin drift current increases, demonstrating that the extension of the spin diffusion length by a strong field does not result in a significant increase in spin current in semiconductors owing to the competing effect of the electric field on diffusion. We also find that there is a spin drift-diffusion crossover field for a process in which the drift and diffusion contribute equally to the spin current, which suggests a possible method of identifying whether the process for a given electric field is in the spin drift or spin diffusion regime. Spin drift-diffusion crossover fields for GaAs are calculated and are found to be quite small. We derive the relations between intrinsic spin diffusion length and the spin drift-diffusion crossover field of a semiconductor for different electron statistical regimes. The findings resulting from this investigation might be important for semiconductor spintronics.

Spin drift and spin diffusion currents in semiconductors

International Nuclear Information System (INIS)

Idrish Miah, M

2008-01-01

On the basis of a spin drift-diffusion model, we show how the spin current is composed and find that spin drift and spin diffusion contribute additively to the spin current, where the spin diffusion current decreases with electric field while the spin drift current increases, demonstrating that the extension of the spin diffusion length by a strong field does not result in a significant increase in spin current in semiconductors owing to the competing effect of the electric field on diffusion. We also find that there is a spin drift-diffusion crossover field for a process in which the drift and diffusion contribute equally to the spin current, which suggests a possible method of identifying whether the process for a given electric field is in the spin drift or spin diffusion regime. Spin drift-diffusion crossover fields for GaAs are calculated and are found to be quite small. We derive the relations between intrinsic spin diffusion length and the spin drift-diffusion crossover field of a semiconductor for different electron statistical regimes. The findings resulting from this investigation might be important for semiconductor spintronics.

Phase-space spinor amplitudes for spin-1/2 systems

International Nuclear Information System (INIS)

Watson, P.; Bracken, A. J.

2011-01-01

The concept of phase-space amplitudes for systems with continuous degrees of freedom is generalized to finite-dimensional spin systems. Complex amplitudes are obtained on both a sphere and a finite lattice, in each case enabling a more fundamental description of pure spin states than that previously given by Wigner functions. In each case the Wigner function can be expressed as the star product of the amplitude and its conjugate, so providing a generalized Born interpretation of amplitudes that emphasizes their more fundamental status. The ordinary product of the amplitude and its conjugate produces a (generalized) spin Husimi function. The case of spin-(1/2) is treated in detail, and it is shown that phase-space amplitudes on the sphere transform correctly as spinors under rotations, despite their expression in terms of spherical harmonics. Spin amplitudes on a lattice are also found to transform as spinors. Applications are given to the phase space description of state superposition, and to the evolution in phase space of the state of a spin-(1/2) magnetic dipole in a time-dependent magnetic field.

Electron charge and spin delocalization revealed in the optically probed longitudinal and transverse spin dynamics in n -GaAs

Science.gov (United States)

Belykh, V. V.; Kavokin, K. V.; Yakovlev, D. R.; Bayer, M.

2017-12-01

The evolution of the electron spin dynamics as consequence of carrier delocalization in n -type GaAs is investigated by the recently developed extended pump-probe Kerr/Faraday rotation spectroscopy. We find that isolated electrons localized on donors demonstrate a prominent difference between the longitudinal and transverse spin relaxation rates in a magnetic field, which is almost absent in the metallic phase. The inhomogeneous transverse dephasing time T2* of the spin ensemble strongly increases upon electron delocalization as a result of motional narrowing that can be induced by increasing either the donor concentration or the temperature. An unexpected relation between T2* and the longitudinal spin relaxation time T1 is found, namely, that their product is about constant, as explained by the magnetic field effect on the spin diffusion. We observe a two-stage longitudinal spin relaxation, which suggests the establishment of spin temperature in the system of exchange-coupled donor-bound electrons.

Spin alignment in heavy and light flavour systems at OPAL

CERN Document Server

Robins, Simon

1999-01-01

Spin alignment of inclusive vector mesons and longitudinal polarization of Lambda hyperons have been measured in a sample of 4.3 million hadronic Z/sup 0/ decays from the OPAL detector at LEP. Leading, light vector mesons have been $9 found to populate preferentially the helicity-zero state, a result which has no firm theoretical explanation. The values of off-diagonal elements of the helicity density matrix are in agreement with a theory based on the Standard $9 Model with coherent fragmentation. The longitudinal polarization of the Lambda is well described by a model in which the constituent strange quark carries all of the hyperon spin.

Quarkonia production at forward rapidity in Pb+Pb collisions at ...

Indian Academy of Sciences (India)

2012-10-02

Oct 2, 2012 ... Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata 700 064, India .... However, the midrapidity values at 200 GeV. *> part. production at forward rapidity centrality. 40-80%. 20-40% ... systematic uncertainties while the centrality-independent uncertainties are ...

Impact of Furfural on Rapid Ethanol Production Using a Membrane Bioreactor

Directory of Open Access Journals (Sweden)

Mohammad J. Taherzadeh

2013-03-01

Full Text Available A membrane bioreactor was developed to counteract the inhibition effect of furfural in ethanol production. Furfural, a major inhibitor in lignocellulosic hydrolyzates, is a highly toxic substance which is formed from pentose sugars released during the acidic degradation of lignocellulosic materials. Continuous cultivations with complete cell retention were performed at a high dilution rate of 0.5 h−1. Furfural was added directly into the bioreactor by pulse injection or by addition into the feed medium to obtain furfural concentrations ranging from 0.1 to 21.8 g L−1. At all pulse injections of furfural, the yeast was able to convert the furfural very rapidly by in situ detoxification. When injecting 21.8 g L−1 furfural to the cultivation, the yeast converted it by a specific conversion rate of 0.35 g g−1 h−1. At high cell density, Saccharomyces cerevisiae could tolerate very high furfural levels without major changes in the ethanol production. During the continuous cultures when up to 17.0 g L−1 furfural was added to the inlet medium, the yeast successfully produced ethanol, whereas an increase of furfural to 18.6 and 20.6 g L−1 resulted in a rapidly decreasing ethanol production and accumulation of sugars in the permeate. This study show that continuous ethanol fermentations by total cell retention in a membrane bioreactor has a high furfural tolerance and can conduct rapid in situ detoxification of medium containing high furfural concentrations.

Enhanced biological production off Chennai triggered by October 1999 super cyclone (Orissa)

Digital Repository Service at National Institute of Oceanography (India)

Madhu, N.V.; Maheswaran, P.A.; Jyothibabu, R.; Sunil, V.; Revichandran, C.; Balasubramanian, T.; Gopalakrishnan, T.C.; Nair, K.K.C.

COMMUNICATIONS CURRENT SCIENCE, VOL. 82, NO. 12, 25 JUNE 2002 *For correspondence. (e - mail: madhu@niokochi.org) Enhanced biological production off Chennai triggered by October 1999 super cyclone (Orissa) N. V. Madhu*, P. A. Maheswaran, R... in the world?s oceans typically have duration of only a few days, but the physical and biological effects due to this perturbation can last up to several weeks 1 ? 4 . The integrated effect from these storm events has the potential to account for a...

Isolated photon production in proton-nucleus collisions at forward rapidity

Science.gov (United States)

Ducloué, B.; Lappi, T.; Mäntysaari, H.

2018-03-01

We calculate isolated photon production at forward rapidities in proton-nucleus collisions in the color glass condensate framework. Our calculation uses dipole cross sections solved from the running coupling Balitsky-Kovchegov equation with an initial condition fit to deep inelastic scattering data. For comparison, we also update the results for the nuclear modification factor for pion production in the same kinematics. We present predictions for future forward RHIC and LHC measurements at √{sN N}=200 GeV and √{sN N}=8 TeV .

Invariant functionals in higher-spin theory

Directory of Open Access Journals (Sweden)

M.A. Vasiliev

2017-03-01

Full Text Available A new construction for gauge invariant functionals in the nonlinear higher-spin theory is proposed. Being supported by differential forms closed by virtue of the higher-spin equations, invariant functionals are associated with central elements of the higher-spin algebra. In the on-shell AdS4 higher-spin theory we identify a four-form conjectured to represent the generating functional for 3d boundary correlators and a two-form argued to support charges for black hole solutions. Two actions for 3d boundary conformal higher-spin theory are associated with the two parity-invariant higher-spin models in AdS4. The peculiarity of the spinorial formulation of the on-shell AdS3 higher-spin theory, where the invariant functional is supported by a two-form, is conjectured to be related to the holomorphic factorization at the boundary. The nonlinear part of the star-product function F⁎(B(x in the higher-spin equations is argued to lead to divergencies in the boundary limit representing singularities at coinciding boundary space–time points of the factors of B(x, which can be regularized by the point splitting. An interpretation of the RG flow in terms of proposed construction is briefly discussed.

Effect of spin rotation coupling on spin transport

International Nuclear Information System (INIS)

Chowdhury, Debashree; Basu, B.

2013-01-01

We have studied the spin rotation coupling (SRC) as an ingredient to explain different spin-related issues. This special kind of coupling can play the role of a Dresselhaus like coupling in certain conditions. Consequently, one can control the spin splitting, induced by the Dresselhaus like term, which is unusual in a semiconductor heterostructure. Within this framework, we also study the renormalization of the spin-dependent electric field and spin current due to the k → ⋅p → perturbation, by taking into account the interband mixing in the rotating system. In this paper we predict the enhancement of the spin-dependent electric field resulting from the renormalized spin rotation coupling. The renormalization factor of the spin electric field is different from that of the SRC or Zeeman coupling. The effect of renormalized SRC on spin current and Berry curvature is also studied. Interestingly, in the presence of this SRC-induced SOC it is possible to describe spin splitting as well as spin galvanic effect in semiconductors. -- Highlights: •Studied effect of spin rotation coupling on the spin electric field, spin current and Berry curvature. •In the k → ⋅p → framework we study the renormalization of spin electric field and spin current. •For an inertial system we have discussed the spin splitting. •Expression for the Berry phase in the inertial system is discussed. •The inertial spin galvanic effect is studied

Effect of spin rotation coupling on spin transport

Energy Technology Data Exchange (ETDEWEB)

Chowdhury, Debashree, E-mail: debashreephys@gmail.com; Basu, B., E-mail: sribbasu@gmail.com

2013-12-15

We have studied the spin rotation coupling (SRC) as an ingredient to explain different spin-related issues. This special kind of coupling can play the role of a Dresselhaus like coupling in certain conditions. Consequently, one can control the spin splitting, induced by the Dresselhaus like term, which is unusual in a semiconductor heterostructure. Within this framework, we also study the renormalization of the spin-dependent electric field and spin current due to the k{sup →}⋅p{sup →} perturbation, by taking into account the interband mixing in the rotating system. In this paper we predict the enhancement of the spin-dependent electric field resulting from the renormalized spin rotation coupling. The renormalization factor of the spin electric field is different from that of the SRC or Zeeman coupling. The effect of renormalized SRC on spin current and Berry curvature is also studied. Interestingly, in the presence of this SRC-induced SOC it is possible to describe spin splitting as well as spin galvanic effect in semiconductors. -- Highlights: •Studied effect of spin rotation coupling on the spin electric field, spin current and Berry curvature. •In the k{sup →}⋅p{sup →} framework we study the renormalization of spin electric field and spin current. •For an inertial system we have discussed the spin splitting. •Expression for the Berry phase in the inertial system is discussed. •The inertial spin galvanic effect is studied.

Spin-Off Successes of SETI Research at Berkeley

Science.gov (United States)

Douglas, K. A.; Anderson, D. P.; Bankay, R.; Chen, H.; Cobb, J.; Korpela, E. J.; Lebofsky, M.; Parsons, A.; von Korff, J.; Werthimer, D.

2009-12-01

Our group contributes to the Search for Extra-Terrestrial Intelligence (SETI) by developing and using world-class signal processing computers to analyze data collected on the Arecibo telescope. Although no patterned signal of extra-terrestrial origin has yet been detected, and the immediate prospects for making such a detection are highly uncertain, the SETI@home project has nonetheless proven the value of pursuing such research through its impact on the fields of distributed computing, real-time signal processing, and radio astronomy. The SETI@home project has spun off the Center for Astronomy Signal Processing and Electronics Research (CASPER) and the Berkeley Open Infrastructure for Networked Computing (BOINC), both of which are responsible for catalyzing a smorgasbord of new research in scientific disciplines in countries around the world. Futhermore, the data collected and archived for the SETI@home project is proving valuable in data-mining experiments for mapping neutral galatic hydrogen and for detecting black-hole evaporation.

Generating highly polarized nuclear spins in solution using dynamic nuclear polarization

DEFF Research Database (Denmark)

Wolber, J.; Ellner, F.; Fridlund, B.

2004-01-01

A method to generate strongly polarized nuclear spins in solution has been developed, using Dynamic Nuclear Polarization (DNP) at a temperature of 1.2K, and at a field of 3.354T, corresponding to an electron spin resonance frequency of 94GHz. Trityl radicals are used to directly polarize 13C...... and other low-γ nuclei. Subsequent to the DNP process, the solid sample is dissolved rapidly with a warm solvent to create a solution of molecules with highly polarized nuclear spins. Two main applications are proposed: high-resolution liquid state NMR with enhanced sensitivity, and the use...

Isotropic transmission of magnon spin information without a magnetic field.

Science.gov (United States)

Haldar, Arabinda; Tian, Chang; Adeyeye, Adekunle Olusola

2017-07-01

Spin-wave devices (SWD), which use collective excitations of electronic spins as a carrier of information, are rapidly emerging as potential candidates for post-semiconductor non-charge-based technology. Isotropic in-plane propagating coherent spin waves (magnons), which require magnetization to be out of plane, is desirable in an SWD. However, because of lack of availability of low-damping perpendicular magnetic material, a usually well-known in-plane ferrimagnet yttrium iron garnet (YIG) is used with a large out-of-plane bias magnetic field, which tends to hinder the benefits of isotropic spin waves. We experimentally demonstrate an SWD that eliminates the requirement of external magnetic field to obtain perpendicular magnetization in an otherwise in-plane ferromagnet, Ni 80 Fe 20 or permalloy (Py), a typical choice for spin-wave microconduits. Perpendicular anisotropy in Py, as established by magnetic hysteresis measurements, was induced by the exchange-coupled Co/Pd multilayer. Isotropic propagation of magnon spin information has been experimentally shown in microconduits with three channels patterned at arbitrary angles.

Laser photoelectron spectroscopy of MnH - and FeH - : Electronic structures of the metal hydrides, identification of a low-spin excited state of MnH, and evidence for a low-spin ground state of FeH

Science.gov (United States)

Stevens, Amy E.; Feigerle, C. S.; Lineberger, W. C.

1983-05-01

The laser photoelectron spectra of MnH- and MnD-, and FeH- and FeD- are reported. A qualitative description of the electronic structure of the low-spin and high-spin states of the metal hydrides is developed, and used to interpret the spectra. A diagonal transition in the photodetachment to the known high-spin, 7Σ+, ground state of MnH is observed. An intense off-diagonal transition to a state of MnH, at 1725±50 cm-1 excitation energy, is attributed to loss of an antibonding electron from MnH-, to yield a low-spin quintet state of MnH. For FeH- the photodetachment to the ground state is an off-diagonal transition, attributed to loss of the antibonding electron from FeH-, to yield a low-spin quartet ground state of FeH. A diagonal transition results in an FeH state at 1945±55 cm-1; this state of FeH is assigned as the lowest-lying high-spin sextet state of FeH. An additional excited state of MnH and two other excited states of FeH are observed. Excitation energies for all the states are reported; vibrational frequencies and bond lengths for the ions and several states of the neutrals are also determined from the spectra. The electron affinity of MnH is found to be 0.869±0.010 eV; and the electron affinity of FeH is determined to be 0.934±0.011 eV. Spectroscopic constants for the various deuterides are also reported.

Off-specular polarized neutron reflectometry study of magnetic dots with a strong shape anisotropy

CERN Document Server

Temst, K; Moshchalkov, V V; Bruynseraede, Y; Fritzsche, H; Jonckheere, R

2002-01-01

We have measured the off-specular polarized neutron reflectivity of a regular array of rectangular magnetic polycrystalline Co dots, which were prepared by a combination of electron-beam lithography, molecular beam deposition, and lift-off processes. The dots have a length-to-width ratio of 4:1 imposing a strong shape anisotropy. The intensity of the off-specular satellite reflection was monitored as a function of the magnetic field applied parallel to the rows of dots and in the plane of the sample, allowing us to analyze the magnetization-reversal process using the four spin-polarized cross sections. (orig.)

Validation and Diagnostic Efficiency of the Mini-SPIN in Spanish-Speaking Adolescents.

Directory of Open Access Journals (Sweden)

LuisJoaquín Garcia-Lopez

Full Text Available Social Anxiety Disorder (SAD is one of the most common mental disorders in adolescence. Many validated psychometric tools are available to diagnose individuals with SAD efficaciously. However, there is a demand for shortened self-report instruments that identify adolescents at risk of developing SAD. We validate the Mini-SPIN and its diagnostic efficiency in overcoming this problem in Spanish-speaking adolescents in Spain.The psychometric properties of the 3-item Mini-SPIN scale for adolescents were assessed in a community (study 1 and clinical sample (study 2.Study 1 consisted of 573 adolescents, and found the Mini-SPIN to have appropriate internal consistency and high construct validity. Study 2 consisted of 354 adolescents (147 participants diagnosed with SAD and 207 healthy controls. Data revealed that the Mini-SPIN has good internal consistency, high construct validity and adequate diagnostic efficiency.Our findings suggest that the Mini-SPIN has good psychometric properties on clinical and healthy control adolescents and general population, which indicates that it can be used as a screening tool in Spanish-speaking adolescents. Cut-off scores are provided.

Validation and Diagnostic Efficiency of the Mini-SPIN in Spanish-Speaking Adolescents.

Science.gov (United States)

Garcia-Lopez, LuisJoaquín; Moore, Harry T A

2015-01-01

Social Anxiety Disorder (SAD) is one of the most common mental disorders in adolescence. Many validated psychometric tools are available to diagnose individuals with SAD efficaciously. However, there is a demand for shortened self-report instruments that identify adolescents at risk of developing SAD. We validate the Mini-SPIN and its diagnostic efficiency in overcoming this problem in Spanish-speaking adolescents in Spain. The psychometric properties of the 3-item Mini-SPIN scale for adolescents were assessed in a community (study 1) and clinical sample (study 2). Study 1 consisted of 573 adolescents, and found the Mini-SPIN to have appropriate internal consistency and high construct validity. Study 2 consisted of 354 adolescents (147 participants diagnosed with SAD and 207 healthy controls). Data revealed that the Mini-SPIN has good internal consistency, high construct validity and adequate diagnostic efficiency. Our findings suggest that the Mini-SPIN has good psychometric properties on clinical and healthy control adolescents and general population, which indicates that it can be used as a screening tool in Spanish-speaking adolescents. Cut-off scores are provided.

Observational signature of high spin at the Event Horizon Telescope

Science.gov (United States)

Gralla, Samuel E.; Lupsasca, Alexandru; Strominger, Andrew

2018-04-01

We analytically compute the observational appearance of an isotropically emitting point source on a circular, equatorial orbit near the horizon of a rapidly spinning black hole. The primary image moves on a vertical line segment, in contrast to the primarily horizontal motion of the spinless case. Secondary images, also on the vertical line, display a rich caustic structure. If detected, this unique signature could serve as a `smoking gun' for a high spin black hole in nature.

Equivalence of ADM Hamiltonian and Effective Field Theory approaches at next-to-next-to-leading order spin1-spin2 coupling of binary inspirals

Energy Technology Data Exchange (ETDEWEB)

Levi, Michele [Institut d' Astrophysique de Paris, Université Pierre et Marie Curie, CNRS-UMR 7095, 98 bis Boulevard Arago, 75014 Paris (France); Steinhoff, Jan, E-mail: michele.levi@upmc.fr, E-mail: jan.steinhoff@ist.utl.pt [Centro Multidisciplinar de Astrofisica, Instituto Superior Tecnico, Universidade de Lisboa, Avenida Rovisco Pais 1, 1049-001 Lisboa (Portugal)

2014-12-01

The next-to-next-to-leading order spin1-spin2 potential for an inspiralling binary, that is essential for accuracy to fourth post-Newtonian order, if both components in the binary are spinning rapidly, has been recently derived independently via the ADM Hamiltonian and the Effective Field Theory approaches, using different gauges and variables. Here we show the complete physical equivalence of the two results, thereby we first prove the equivalence of the ADM Hamiltonian and the Effective Field Theory approaches at next-to-next-to-leading order with the inclusion of spins. The main difficulty in the spinning sectors, which also prescribes the manner in which the comparison of the two results is tackled here, is the existence of redundant unphysical spin degrees of freedom, associated with the spin gauge choice of a point within the extended spinning object for its representative worldline. After gauge fixing and eliminating the unphysical degrees of freedom of the spin and its conjugate at the level of the action, we arrive at curved spacetime generalizations of the Newton-Wigner variables in closed form, which can also be used to obtain further Hamiltonians, based on an Effective Field Theory formulation and computation. Finally, we make use of our validated result to provide gauge invariant relations among the binding energy, angular momentum, and orbital frequency of an inspiralling binary with generic compact spinning components to fourth post-Newtonian order, including all known sectors up to date.