Handbook for nuclear non-proliferation

International Nuclear Information System (INIS)

Lee, Byung Wook; Oh, Keun Bae; Lee, Kwang Seok; Lee, Dong Jin; Ko, Han Seok.

1997-05-01

This book analyzed international non-proliferation regime preventing from spread of nuclear weapon. This book took review from the historical background of non-proliferation regime to the recent changes and status. The regime, here, is divided into multilateral and bilateral regime. First of all, this book reports four multilateral treaties concluded for non-proliferation such as NPT, NWFZ, CTBT and others. Secondly, international organization and regimes concerned with non-proliferation are analyzed with emphasis of UN, IAEA, ZC and NSG, Regional Safeguards System and international conference. Finally, this book report the current circumstances of nuclear cooperation agreement related with Korea which is an important means for bilateral regime. (author). 13 tabs., 2 figs

Handbook for nuclear non-proliferation

Energy Technology Data Exchange (ETDEWEB)

Lee, Byung Wook; Oh, Keun Bae; Lee, Kwang Seok; Lee, Dong Jin; Ko, Han Seok

1997-05-01

This book analyzed international non-proliferation regime preventing from spread of nuclear weapon. This book took review from the historical background of non-proliferation regime to the recent changes and status. The regime, here, is divided into multilateral and bilateral regime. First of all, this book reports four multilateral treaties concluded for non-proliferation such as NPT, NWFZ, CTBT and others. Secondly, international organization and regimes concerned with non-proliferation are analyzed with emphasis of UN, IAEA, ZC and NSG, Regional Safeguards System and international conference. Finally, this book report the current circumstances of nuclear cooperation agreement related with Korea which is an important means for bilateral regime. (author). 13 tabs., 2 figs.

76 FR 30986 - Bureau of International Security and Nonproliferation; Imposition of Nonproliferation Measures...

Science.gov (United States)

2011-05-27

... DEPARTMENT OF STATE [Public Notice 7485] Bureau of International Security and Nonproliferation; Imposition of Nonproliferation Measures Against Foreign Persons, Including a Ban on U.S. Government... of foreign entities and one foreign person have engaged in activities that warrant the imposition of...

Nuclear arbitration: Interpreting non-proliferation agreements

International Nuclear Information System (INIS)

Tzeng, Peter

2015-01-01

At the core of the nuclear non-proliferation regime lie international agreements. These agreements include, inter alia, the Nuclear Non-proliferation Treaty, nuclear co-operation agreements and nuclear export control agreements.1 States, however, do not always comply with their obligations under these agreements. In response, commentators have proposed various enforcement mechanisms to promote compliance. The inconvenient truth, however, is that states are generally unwilling to consent to enforcement mechanisms concerning issues as critical to national security as nuclear non-proliferation.3 This article suggests an alternative solution to the non-compliance problem: interpretation mechanisms. Although an interpretation mechanism does not have the teeth of an enforcement mechanism, it can induce compliance by providing an authoritative interpretation of a legal obligation. Interpretation mechanisms would help solve the non-compliance problem because, as this article shows, in many cases of alleged non-compliance with a non-proliferation agreement, the fundamental problem has been the lack of an authoritative interpretation of the agreement, not the lack of an enforcement mechanism. Specifically, this article proposes arbitration as the proper interpretation mechanism for non-proliferation agreements. It advocates the establishment of a 'Nuclear Arbitration Centre' as an independent branch of the International Atomic Energy Agency (IAEA), and recommends the gradual introduction of arbitration clauses into the texts of non-proliferation agreements. Section I begins with a discussion of international agreements in general and the importance of interpretation and enforcement mechanisms. Section II then discusses nuclear non-proliferation agreements and their lack of interpretation and enforcement mechanisms. Section III examines seven case studies of alleged non-compliance with non-proliferation agreements in order to show that the main problem in many cases

Canada's nuclear non-proliferation policy

International Nuclear Information System (INIS)

1982-05-01

Canada's non-proliferation safeguards policy has two objectives: 1) to promote a more effective and comprehensive international non-proliferation regime; and 2) to ensure that Canadian nuclear exports will not be used for any nuclear explosive purpose. By emphasizing the key role of the Non-Proliferation Treaty, promoting reliance upon and improvements in the IAEA safeguards system, treating nuclear weapon and non-weapon states alike, and working for new approaches covering reprocessing, Canada promotes attainment of the first objective. The second is served through the network of bilateral nuclear agreements that Canada has put into place with its partners. The Canadian objective in post-INFCE forums is to persuade the international community to devise a more effective and comprehensive non-proliferation regime into which Canada and other suppliers may subsume their national requirements

Perspectives of the nuclear non-proliferation regime

International Nuclear Information System (INIS)

Koungou, Leon

2004-01-01

To join traditional methods and new approaches of 'non-proliferation'. This is a technical method and the best way to fight against 'non-proliferation' which is facing few preoccupations: knowledge's disseminations; technologies; equipments and weapons that should be stopped. As it's important to note the return of nuclear danger as the end of confrontation between west-east which should be reduce. As the adaptation of mechanisms is necessary today, as it is important to react about states' incitations to violate international engagement of non-proliferation. Areas control allows finding out change and evolution, but more insufficient. Functional difficulties show that the IAEA (International Agency of Atomic Energy) does not work good. Safeguard system does not allow to respect 'non-proliferation' engagements; for instance 'junkies states' that they cannot dissuade traditional methods. The fight of 'non-proliferation' shows new progresses with fearing methods of prevention actions and heaviest international controls of exportation. The target of this is very ambitious. This new method is self-successful because it contributes to re-enforce international security when defeating acquisition of nuclear and mass destruction weapons by non-states factors. Therefore non-proliferation regime and especially 'non-proliferation treaty' remains delicate as long as some militaries state such USA will reject their 'non-proliferation' engagement. (author) [fr

Management Principles for Nonproliferation Organizations

International Nuclear Information System (INIS)

Frazar, Sarah L.; Hund, Gretchen

2012-01-01

This paper identifies business models and six management principles that can be applied by a nonproliferation organization to maximize the value and effectiveness of its products. The organizations responsible for reducing the nuclear proliferation threat have experienced a substantial growth in responsibility and visibility since the September 11 attacks. Since then, the international community has witnessed revelations of clandestine nuclear facilities, nuclear black markets, periodic nuclear tests, and a resurgence of interest by countries worldwide in developing nuclear capabilities. The security environment will likely continue to evolve in unexpected ways since most of the proliferation threats with which the world will be forced to contend remain unforeseen. To better prepare for and respond to this evolving security environment, many nonproliferation organizations are interested in finding new or better ways to increase the effectiveness and efficiency of their operations. Of course, all organizations, whether they are market driven or non-profit, must operate effectively and efficiently if they are to succeed. Indeed, as this study demonstrates, many of the management principles that this study recommends can help all organizations succeed. However, this study pays particular attention to nonproliferation organizations because of the mission they are responsible for fulfilling. Nonproliferation organizations, including nonproliferation programs that operate within a larger national security organization, are responsible for reducing the threat of nuclear, chemical and biological weapons. These organizations have an enduring mandate from the public and the international community not to fail in the completion of their mission for failure could have detrimental impacts on international security, public health and the environment. Moreover, the public expects nonproliferation organizations and programs to fulfill their mission, even when resources are limited

Management Principles for Nonproliferation Organizations

Energy Technology Data Exchange (ETDEWEB)

Frazar, Sarah L.; Hund, Gretchen

2012-03-06

This paper identifies business models and six management principles that can be applied by a nonproliferation organization to maximize the value and effectiveness of its products. The organizations responsible for reducing the nuclear proliferation threat have experienced a substantial growth in responsibility and visibility since the September 11 attacks. Since then, the international community has witnessed revelations of clandestine nuclear facilities, nuclear black markets, periodic nuclear tests, and a resurgence of interest by countries worldwide in developing nuclear capabilities. The security environment will likely continue to evolve in unexpected ways since most of the proliferation threats with which the world will be forced to contend remain unforeseen. To better prepare for and respond to this evolving security environment, many nonproliferation organizations are interested in finding new or better ways to increase the effectiveness and efficiency of their operations. Of course, all organizations, whether they are market driven or non-profit, must operate effectively and efficiently if they are to succeed. Indeed, as this study demonstrates, many of the management principles that this study recommends can help all organizations succeed. However, this study pays particular attention to nonproliferation organizations because of the mission they are responsible for fulfilling. Nonproliferation organizations, including nonproliferation programs that operate within a larger national security organization, are responsible for reducing the threat of nuclear, chemical and biological weapons. These organizations have an enduring mandate from the public and the international community not to fail in the completion of their mission for failure could have detrimental impacts on international security, public health and the environment. Moreover, the public expects nonproliferation organizations and programs to fulfill their mission, even when resources are limited

The handbook of nuclear non-proliferation

International Nuclear Information System (INIS)

Yang, M. H.; Lee, B. W.; Oh, K. B.; Lee, H. M.; Ko, H. S.; Ryu, J. S.; Lee, K. S.

2003-07-01

This report analyzed international non-proliferation regime preventing from spread of nuclear weapon. This report took review from the historical background of non-proliferation regime to the recent changes and current status. It is here divided into multilateral and bilateral regime. First of all, this report dealt four multilateral treaties concluded for international non-proliferation such as NPT, NWFZ, CTBT and others. And international organization and regimes concerned with non-proliferation are also analyzed focused on UN, IAEA, ZC and NSG, regional safeguards system and international conferences. In addition, this report reviewed the nuclear cooperation agreement related with Korea which is a important tool for bilateral regime

New trends of activity on supporting of non-proliferation regime

International Nuclear Information System (INIS)

Issaeva, G.M.; Tyupkina, O.G.

2002-01-01

Taking into account the necessity of all possible strengthening of non-proliferation regimes Kazakhstan participates in a number of agreements and associations: Nuclear Non-proliferation Treaty, Comprehensive Test-Ban-Treaty, International Atomic Energy Agency, Nuclear Supplier Group, Missile Technology Control Regime, Conference on Disarmament, etc. The Cooperative Threat Reduction Program (CTR) greatly influenced on the development on non-proliferation regime in Kazakhstan. During initial stage of CTR activity (1993-1995) military projects prevailed. Later (1995-1997) the projects on liquidation of infrastructure for nuclear and bio- weapons were successfully realized. Last years, since 1999, the attention was shifted towards proliferation prevention of hazardous nuclear and biological materials. Recent terrorist acts and world community activity on global safety strengthening underline an urgency of quite new problems that entirely applied to Kazakhstan: monitoring of hazardous materials; enhancement of safety systems of 'risky' facilities and technologies; creation and/or upgrading of safety systems for industry infrastructure. The proposals of these new trends of non-proliferation have been developed. Development of physical protection system for oil and gas industry infrastructure of Kazakhstan based on safety concepts of nuclear facilities; Evaluation of radionuclide contamination and safety of oil and gas facilities of the Caspian region; Counteraction to nuclear materials proliferation; Cooperative approaches in preventing/reducing of illicit trafficking and use of WMD-related explosive materials. Implementation of the project would make of substantial contribution to successful solution of either regional or global safety problem

Non-proliferation and multinational enterprises

International Nuclear Information System (INIS)

1979-04-01

The paper supplements CC/WG.2/9 in presenting the Japanese delegation's contribution in the areas of non-proliferation and multi-national enterprises. The paper questions whether multinational enrichment enterprises would constitute a significant non-proliferation factor, noting that the nature of the venture might create a potential for the dissemination of sensitive information. The paper also argues that a multi-national venture which was not economically competitive (with national facilities) would have questionable viability. The conclusion is that non-proliferation advantages, if any, would be a result, not an objective of such a venture

Systems resilience: a new analytical framework for nuclear nonproliferation

International Nuclear Information System (INIS)

Pregenzer, Arian Leigh

2011-01-01

This paper introduces the concept of systems resilience as a new framework for thinking about the future of nonproliferation. Resilience refers to the ability of a system to maintain its vital functions in the face of continuous and unpredictable change. The nonproliferation regime can be viewed as a complex system, and key themes from the literature on systems resilience can be applied to the nonproliferation system. Most existing nonproliferation strategies are aimed at stability rather than resilience, and the current nonproliferation system may be over-constrained by the cumulative evolution of strategies, increasing its vulnerability to collapse. The resilience of the nonproliferation system can be enhanced by diversifying nonproliferation strategies to include general international capabilities to respond to proliferation and focusing more attention on reducing the motivation to acquire nuclear weapons in the first place. Ideas for future research, include understanding unintended consequences and feedbacks among nonproliferation strategies, developing methodologies for measuring the resilience of the nonproliferation system, and accounting for interactions of the nonproliferation system with other systems on larger and smaller scales.

Systems resilience : a new analytical framework for nuclear nonproliferation.

Energy Technology Data Exchange (ETDEWEB)

Pregenzer, Arian Leigh

2011-12-01

This paper introduces the concept of systems resilience as a new framework for thinking about the future of nonproliferation. Resilience refers to the ability of a system to maintain its vital functions in the face of continuous and unpredictable change. The nonproliferation regime can be viewed as a complex system, and key themes from the literature on systems resilience can be applied to the nonproliferation system. Most existing nonproliferation strategies are aimed at stability rather than resilience, and the current nonproliferation system may be over-constrained by the cumulative evolution of strategies, increasing its vulnerability to collapse. The resilience of the nonproliferation system can be enhanced by diversifying nonproliferation strategies to include general international capabilities to respond to proliferation and focusing more attention on reducing the motivation to acquire nuclear weapons in the first place. Ideas for future research, include understanding unintended consequences and feedbacks among nonproliferation strategies, developing methodologies for measuring the resilience of the nonproliferation system, and accounting for interactions of the nonproliferation system with other systems on larger and smaller scales.

Femtosecond upconverted photocurrent spectroscopy of InAs quantum nanostructures

Energy Technology Data Exchange (ETDEWEB)

Yamada, Yasuhiro [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Tex, David M.; Kanemitsu, Yoshihiko, E-mail: kanemitu@scl.kyoto-u.ac.jp [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Japan Science and Technology Agency, CREST, Kyoto University, Uji, Kyoto 611-0011 (Japan); Kamiya, Itaru [Toyota Technological Institute, Nagoya, Aichi 468-8511 (Japan)

2015-07-06

The carrier upconversion dynamics in InAs quantum nanostructures are studied for intermediate-band solar-cell applications via ultrafast photoluminescence and photocurrent (PC) spectroscopy based on femtosecond excitation correlation (FEC) techniques. Strong upconverted PC-FEC signals are observed under resonant excitation of quantum well islands (QWIs), which are a few monolayer-thick InAs quantum nanostructures. The PC-FEC signal typically decays within a few hundred picoseconds at room temperature, which corresponds to the carrier lifetime in QWIs. The photoexcited electron and hole lifetimes in InAs QWIs are evaluated as functions of temperature and laser fluence. Our results provide solid evidence for electron–hole–hole Auger process, dominating the carrier upconversion in InAs QWIs at room temperature.

Evolution and resilience of the nuclear nonproliferation regime

International Nuclear Information System (INIS)

Pregenzer, Arian L.

2014-01-01

This paper introduces the concept of systems resilience as a new framework for thinking about the future of the nonproliferation regime. Resilience refers to the ability of a system to maintain its vital functions in the face of continuous and unpredictable change. First, I make the case that the nonproliferation regime can be viewed as a complex system. Next, I discuss key themes from the literature on systems resilience and apply them to the nonproliferation system: the difference between resilience and stability; the need for evolution to maintain function; the importance of functional diversity; and the concept of the adaptive cycle. I show that most existing nonproliferation strategies are aimed at stability rather than resilience and that the current nonproliferation system may be over-constrained by the cumulative evolution of strategies. According to the literature on systems resilience, this increases its vulnerability to collapse. I argue that the resilience of the nonproliferation system can be enhanced by increasing international participation in setting the nonproliferation agenda, developing general international response capabilities, focusing on non-coercive approaches to decreasing demand, and applying systems thinking more rigorously to nonproliferation

Evolution and resilience of the nuclear nonproliferation regime

Energy Technology Data Exchange (ETDEWEB)

Pregenzer, Arian L. [Senior Scientist, Retired, Sandia National Laboratories, 13013 Arroyo de Vista NE, Albuquerque, NM 87111 (United States)

2014-05-09

This paper introduces the concept of systems resilience as a new framework for thinking about the future of the nonproliferation regime. Resilience refers to the ability of a system to maintain its vital functions in the face of continuous and unpredictable change. First, I make the case that the nonproliferation regime can be viewed as a complex system. Next, I discuss key themes from the literature on systems resilience and apply them to the nonproliferation system: the difference between resilience and stability; the need for evolution to maintain function; the importance of functional diversity; and the concept of the adaptive cycle. I show that most existing nonproliferation strategies are aimed at stability rather than resilience and that the current nonproliferation system may be over-constrained by the cumulative evolution of strategies. According to the literature on systems resilience, this increases its vulnerability to collapse. I argue that the resilience of the nonproliferation system can be enhanced by increasing international participation in setting the nonproliferation agenda, developing general international response capabilities, focusing on non-coercive approaches to decreasing demand, and applying systems thinking more rigorously to nonproliferation.

Polarized and resonant Raman spectroscopy on single InAs nanowires

Science.gov (United States)

Möller, M.; de Lima, M. M., Jr.; Cantarero, A.; Dacal, L. C. O.; Madureira, J. R.; Iikawa, F.; Chiaramonte, T.; Cotta, M. A.

2011-08-01

We report polarized Raman scattering and resonant Raman scattering studies on single InAs nanowires. Polarized Raman experiments show that the highest scattering intensity is obtained when both the incident and analyzed light polarizations are perpendicular to the nanowire axis. InAs wurtzite optical modes are observed. The obtained wurtzite modes are consistent with the selection rules and also with the results of calculations using an extended rigid-ion model. Additional resonant Raman scattering experiments reveal a redshifted E1 transition for InAs nanowires compared to the bulk zinc-blende InAs transition due to the dominance of the wurtzite phase in the nanowires. Ab initio calculations of the electronic band structure for wurtzite and zinc-blende InAs phases corroborate the observed values for the E1 transitions.

Nuclear Non-Proliferation Policy Act of 1977. Hearings before the Subcommittee on Energy Research and Development of the Committee on Energy and Natural Resources, United States Senate, Ninety-Fifth Congress, First Session on S. 897 and S. 1432

International Nuclear Information System (INIS)

Anon.

1978-01-01

On April 7, 1977, President Carter announced his nuclear power policy. The policy statement set forth seven specific objectives for the future use of nuclear energy in this country and the rest of the world. The two proposed instruments for implementing this policy are the revised fiscal year 1978 ERDA authorization draft bill and S. 1432, the Nuclear Non-Proliferation Act of 1977. These legislative proposals are linked in that S. 1432 is designed to establish a non-proliferation framework with specific objectives established for the ERDA nuclear energy programs. The ERDA authorization bill is the budgetary vehicle to implement those objectives. The Committee on Energy and Natural Resources obtained joint referral of certain portions of the Nuclear Non-Proliferation Act to insure that non-proliferation policy is implemented in a manner consistent with the policy of having sufficient energy for this country and foreign countries in the future. The Subcommittee on Energy Research and Development must examine the costs and the consequences of various initiatives before they are implemented. F or example, the proposal to guarantee uranium enrichment services for foreign nations poses specific requirements on ERDA to expand considerably our enrichment capacity by the year 2000. Without reprocessing, it is expected that spent fuel rods from abroad will be returned to this country for storage with attendant costs and siting decisions. Also, international fuel-cycle evaluation programs must be carefully examined to insure that all options, including regional fuel cycle centers with international controls and inspection, are considered in seeking international approaches to the non-proliferation objectives. At the June 10 hearing, the subcommittee received testimony on S. 1432, the bill prepared by the administration. The hearings on September 13 and 14 focused on S. 897. Statements by many witnesses are included

INA-Rxiv: The Missing Puzzle in Indonesia’s Scientific Publishing Workflow

Science.gov (United States)

Rahim, R.; Irawan, D. E.; Zulfikar, A.; Hardi, R.; Arliman S, L.; Gultom, E. R.; Ginting, G.; Wahyuni, S. S.; Mesran, M.; Mahjudin, M.; Saputra, I.; Waruwu, F. T.; Suginam, S.; Buulolo, E.; Abraham, J.

2018-04-01

INA-Rxiv is the first Indonesia preprint server marking the new development initiated by the open science community. This study aimed at describing the development of INA-Rxiv and its conversations. It usedanalyzer of Inarxiv.id, WhatsApp Group Analyzer, and Twitter Analytics as the tools for data analysis complemented with observation.The results showed that INA-Rxiv users are growing because of the numerous discussions in social media, e.g.WhatsApp,as well as some other positive response of writers who have been using INA- Rxiv. The perspective of growth mindset and the implication of INA-Rxiv movement for filling up the gap in accelerating scientific dissemination process are presented at the end of this article.

22 CFR 40.68 - Aliens subject to INA 222(g).

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Aliens subject to INA 222(g). 40.68 Section 40... § 40.68 Aliens subject to INA 222(g). An alien who, under the provisions of INA 222(g), has voided a... new nonimmigrant visa unless the alien complies with the requirements in 22 CFR 41.101 (b) or (c...

Broadening Industry Governance to Include Nonproliferation

Energy Technology Data Exchange (ETDEWEB)

Hund, Gretchen; Seward, Amy M.

2008-11-11

As industry is the first line of defense in detecting and thwarting illicit trade networks, the engagement of the private sector is critical to any government effort to strengthen existing mechanisms to protect goods and services throughout the supply chain. This study builds on previous PNNL work to continue to evaluate means for greater industry engagement to complement and strengthen existing governmental efforts to detect and stem the trade of illicit goods and to protect and secure goods that could be used in making a weapon of mass destruction. Specifically, the study evaluates the concept of Industry Self Regulation, defined as a systematic voluntary program undertaken by an industry or by individual companies to anticipate, implement, supplement, or substitute for regulatory requirements in a given field, generally through the adoption of best practices. Through a series of interviews with companies with a past history of non-compliance, trade associations and NGOs, the authors identify gaps in the existing regulatory infrastructure, drivers for a self regulation approach and the form such an approach might take, as well as obstacles to be overcome. The authors conclude that it is at the intersection of industry, government, and security that—through collaborative means—the effectiveness of the international nonproliferation system—can be most effectively strengthened to the mutual benefit of both government and the private sector. Industry has a critical stake in the success of this regime, and has the potential to act as an integrating force that brings together the existing mechanisms of the global nonproliferation regime: export controls, physical protection, and safeguards. The authors conclude that industry compliance is not enough; rather, nonproliferation must become a central tenant of a company’s corporate culture and be viewed as an integral component of corporate social responsibility (CSR).

Spin Injection, Manipulation, and Detection, in InAs Nanodevices

Science.gov (United States)

Jones, G. M.; Jonker, B. T.; Bennett, B. R.; Meyer, J. R.; Twigg, M. E.; Reinecke, T. L.; Park, D.; Pereverzev, S. V.; Badescu, C. S.; Li, C. H.; Hanbicki, A. T.; van'terve, O.; Vurgaftman, I.

2008-03-01

In this talk the authors will discuss their progress using InAs heterostructures to produce spin-polarized injection and detection, as well as manipulation of coherent spin-polarized electrons for a spin-based FET (SpinFET). High-quality n-type InAs heterostructures demonstrate many favorable characteristics necessary to the study of spin dynamics, including 2DEG's with small effective mass (m* = 0.023) and large g-factor (g = -15). Previously, high-mobility InAs heterostructures have been demonstrated in which electrons pass ballistically over hundreds of nanometers up to room temperature. Our devices seek to exploit the strong Spin-Orbit effect present in InAs to manipulate coherent spin-polarized electrons during transport, by producing perpendicular electric field using isolated top-gates fabricated over the electron transport region.

Israel's position on non-proliferation

International Nuclear Information System (INIS)

Marom, R.

1986-01-01

Israel maintained that the complex international system and worldwide political tension created a situation in which comprehensive plans of disarmament could not produce any positive result. The deadlock in the field of general and complete disarmament has brought Israel to the realization that one possible way to alleviate the stalemate could be progress by stages through partial measures of disarmament. Israel's position on non-proliferation indicates that the establishment of a nuclear-weapon-free-zone (NWFZ), as it relates to the Middle-East, could serve as a credible alternative to the unilateral adherence to the Non-Proliferation of Nuclear Weapon (NPT) and an effective measure of non-proliferation in the region. (Author)

Women Fellows of INAE | Women in Science | Initiatives | Indian ...

Indian Academy of Sciences (India)

Women Fellows of INAE. INAE - Indian National Academy of Engineering. Ms. Alpa Sheth Civil Engineering. Prof. Bharathi Bhat Electronics & Communication Engineering. Prof. Dipanwita Roy Chowdhury Computer Engineering and Information Technology. Prof. Kamala Krithivasan Computer Engineering and Information ...

Growth and characterization of InAs quantum dots on silicon

Energy Technology Data Exchange (ETDEWEB)

Hansen, L.; Ankudinov, A.; Bensing, F.; Wagner, J.; Wagner, V.; Geurts, J. [Wuerzburg Univ. (Germany). Lehrstuhl fuer Experimentelle Physik 3; Ade, G.; Hinze, P. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Waag, A. [Ulm Univ. (Germany). Abt. Halbleiterphysik

2001-03-08

We present a comprehensive investigation of molecular beam epitaxial (MBE) grown InAs quantum dots (QD) on silicon (001) and (111) by reflection high energy electron diffraction (RHEED) and Raman spectroscopy in UHV environment and ex-situ by atomic force microscopy (AFM) and transmission electron microscopy (TEM). Two different ways were developed to prepare up to 10{sup 11} cm{sup -2} InAs QDs on Si(001). One is the conventional mode by exceeding a critical thickness of deposition at which 2D growth changes towards a 3D growth mode. A second way is a dewetting transition, induced by cooling an approximately 1 ML thin 2D InAs layer from growth temperature below a critical temperature at which RHEED indicates the formation of nanoislands. Samples grown in both manners show significant differences in morphology and shape though RHEED, TEM and Raman studies correspondingly indicate strain relaxation. On Si(111) InAs grows in the common temperature range for InAs growth ({proportional_to}400 C) in flat clusters separated by deep trenches. A previous passivation of the Si(111) surface with arsenic at {proportional_to}700 C on the other hand leads to the formation of large InAs nanocrystals. (orig.)

The presence of INA proteins on the surface of single cells of Pseudomonas syringae R10.79 isolated from rain

Science.gov (United States)

Šantl-Temkiv, Tina; Ling, Meilee; Holm, Stine; Finster, Kai; Boesen, Thomas

2016-04-01

our surprise, exposure of cells to low temperatures, which is normally considered to be the main driver of the INA protein synthesis, had no or even a negative effect on the proportion of cells with INA proteins. Our results suggest that at certain conditions a high proportion of Pseudomonas syringae cells produces INA proteins and that this proportion depends on the physiological state of the cells. This and similar studies will ultimately improve our understanding of the quantitative role bacterial INA proteins play in atmospheric processes. References DeMott, P., Prenni, A.J. (2010): New Directions: Need for defining the numbers and sources of biological aerosols acting as ice nuclei. Atmos Environ. doi: 10.1016/j.atmosenv.2010.02.032 Šantl-Temkiv, T., Sahyoun, M., Finster, K., Hartmann, S., Augustin-Bauditz, S, Stratmann, F. et al (2015): Characterization of airborne ice-nucleation-active bacteria and bacterial fragments. Atmos Environ. doi: ttp://doi.org/10.1016/j.atmosenv.2015.02.060

Robust Indicators of Nonproliferation Performance

Energy Technology Data Exchange (ETDEWEB)

Cowan, Mara R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kurzrok, Andrew J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2014-02-13

Understanding how the nuclear industry may benefit from self-regulation is closely linked with understanding how to report compliance activities for nonproliferation and export control objectives, as well as how to distinguish high and low compliance performance. Drawing on the corporate sustainability reporting model, nuclear and dual-use commodities industries can frame socially responsible self-regulatory activities to distinguish themselves as good nonproliferators.

Komunikační mix Svatebního salonu INA

OpenAIRE

Rybníčková, Michala

2015-01-01

Rybníčková, M. Marketing mix for Wedding Boutique INA. Bachelor thesis, Brno: Mendel university in Brno, 2015 This Bechelor thesis focuses on the marketing mix for the company Wedding Boutique INA. Survey results are used to evaluate the effectiveness of marketing tools currently used by INA. Furthermore, the results are used to recommend improvements to the marketing mix. Thesis also includes calculation of costs and scheduling for the year 2015.

Future non-proliferation challenges

International Nuclear Information System (INIS)

Yelchenko, Volodymyr

2008-01-01

Having chaired the Second Session of the Preparatory Committee Mr. Volodymyr Yelchenko noted that the NPT States parties reaffirmed the important role of the Treaty as the cornerstone of the global non-proliferation regime. They stressed that non-compliance with the Treaty provisions by States parties undermined non-proliferation and placed emphasis on the mutually reinforcing nature of disarmament and non-proliferation, and due respect for the right of States parties to the peaceful use of nuclear energy in conformity with the treaty. They reaffirmed the importance of promoting the peaceful uses of nuclear energy and international nuclear cooperation for peaceful purposes in ways consistent with the non-proliferation goal of the Treaty. The universality aspect was brought to the front with the lack of progress in this area. States parties called upon India, Israel and Pakistan to accede to the Treaty as non-nuclear-weapons states, promptly and without conditions and to bring into force comprehensive safeguards agreements, together with Additional Protocols, for ensuring non-proliferation. There is concern that non-States actors could gain access to weapons of mass destruction. One of the underlying themes at the Second Prepcom was the total elimination of nuclear weapons as the only absolute guarantee against their proliferation. Negative consequences to nuclear non-proliferation were also mentioned in the context of the abrogation of the Anti-Ballistic Missile Treaty and the development of missile defense systems, with the risk of a new arms race on Earth and in outer space. The importance of the immediate commencement of negotiations in the Conference of Disarmament on a treaty concerning fissile material for nuclear weapons or other nuclear explosive devices and the urgent conclusion of such a treaty as a beneficial step towards non-proliferation was stressed. The NPT states parties reaffirmed the role of the IAEA as the sole competent authority responsible for

Nuclear nonproliferation strategy in Asia

International Nuclear Information System (INIS)

Jenkins, F.W.

1989-07-01

The most immediate danger of a further spread of nuclear weapons in Asia is in South Asia, where both India and Pakistan have developed the means of producing nuclear explosive materials. In East Asia, North Korea appears to be in the early stages of a weapon-related nuclear program, and before the end of the century South Korea or Taiwan could revive their past efforts to move closer to a nuclear weapons capability. Over the longer run, Japan could conceivably decide to abandon its present strong opposition to the acquisition of nuclear Weapons. At present, the United States has largely separate approaches to the nuclear weapon proliferation problems in South Asia and in East Asia. This paper argues that these separate approaches should be strengthened and integrated into a broader regional nonproliferation strategy. This regional strategy would have three major strands: inducing India and Pakistan to agree not to produce nuclear weapons or test nuclear explosive devices for a specific period; bolstering the existing nonproliferation regime, principally by maintaining nonproliferation incentives and involving China more in the nonproliferation regime; and encouraging regional cooperation in peaceful uses of nuclear energy

Progress in low light-level InAs detectors- towards Geiger-mode detection

Science.gov (United States)

Tan, Chee Hing; Ng, Jo Shien; Zhou, Xinxin; David, John; Zhang, Shiyong; Krysa, Andrey

2017-05-01

InAs avalanche photodiodes (APDs) can be designed such that only electrons are allowed to initiate impact ionization, leading to the lowest possible excess noise factor. Optimization of wet chemical etching and surface passivation produced mesa APDs with bulk dominated dark current and responsivity that are comparable and higher, respectively, than a commercial InAs detector. Our InAs electron-APDs also show high stability with fluctuation of 0.1% when operated at a gain of 11.2 over 60 s. These InAs APDs can detect very weak signal down to 35 photons per pulse. Fabrication of planar InAs by Be implantation produced planar APDs with bulk dominated dark current. Annealing at 550 °C was necessary to remove implantation damage and to activate Be dopants. Due to minimal diffusion of Be, thick depletion of 8 μm was achieved. Since the avalanche gain increases exponentially with the thickness of avalanche region, our planar APD achieved high gain > 300 at 200 K. Our work suggest that both mesa and planar InAs APDs can exhibit high gain. When combined with a suitable preamplifier, single photon detection using InAs electron-APDs could be achieved.

The Asian countries and the non-proliferation treaty prorogation

International Nuclear Information System (INIS)

Hoffmann, N.

1995-01-01

This work deals with the non-proliferation treaty prorogation of Asia. The position of the asian countries under the old non-proliferation treaty is given. It includes the 1968 non-proliferation treaty signatories, the calling in question again and the criticisms revealed by the asian countries. The positions and the open forecasts expressed on the non-proliferation treaty prorogation and the article on the elimination of the nuclear weapons are also given. (O.L.)

Integrated Support Center for Nuclear Nonproliferation and Security

International Nuclear Information System (INIS)

Kimura, Naohito; Naoi, Yosuke

2010-01-01

In April 2010, at the Nuclear Security Summit, Japan demonstrated its commitment to the strengthening of nuclear non-proliferation and nuclear security and announced the establishment of the Integrated Comprehensive Support Center for Nuclear Non-proliferation and Nuclear Security in the Japan Atomic Energy Agency (JAEA), under the guidance and authority of the Ministry of Education, Culture, Sports and Science and Technology (MEXT), and in cooperation with other ministries. The goal of the Center is to strengthen nuclear non-proliferation and security in emerging nuclear power countries by sharing Japan's accumulated experiences in its peaceful use of nuclear energy. To achieve its goal, the Center serves three functions: (1) human resource and capacity building, (2) infrastructure development and technical assistance and (3) international coordination and cooperation. The Center will offer three types of training courses to strengthen human resources and capacity building in emerging nuclear power countries. In the Training Course on Nuclear Security, the participants will learn the design and evaluation process for physical protection and detection of and response to illegal or unauthorized acts related to nuclear materials. They will learn these issues not only through lectures and training but also using mockup facilities and virtual reality systems. Second, in the Training Course on Safeguards and State System of Accounting for and Control of Nuclear Material (SSAC), the Center will teach the experience of advanced safeguards activities in Japan for its full-scale nuclear fuel cycle facilities as a non-nuclear weapon state. The participants will learn the IAEA and national safeguards systems, the material accounting system and inspector activities. Third, in the Training on the International Nuclear Nonproliferation Framework, the participants will learn the international framework of nuclear non-proliferation including the IAEA safeguards system and

Homo- and heteroepitaxial growth behavior of upright InAs nanowires on InAs and GaAs substrates

Energy Technology Data Exchange (ETDEWEB)

Bauer, Jens; Gottschalch, Volker; Paetzelt, Hendrik [Institut fuer Anorganische Chemie, Universitaet Leipzig, Johannesallee 29, D-04103 Leipzig (Germany); Wagner, Gerald [Institut fuer Kristallographie und Mineralogie, Universitaet Leipzig, Linnestr. 5, D-04103 Leipzig (Germany); Pietsch, Ulrich [Festkoerperphysik, Universitaet Siegen, D-57068 Siegen (Germany)

2008-07-01

Semiconductor nanowires (NW) acquire recently attraction because of promising new application fields in electronics and optoelectronic. We applied the vapor-liquid-solid mechanism with gold seeds in combination with low-pressure metal-organic vapor phase epitaxy (LP-MOVPE) to achieve replicable InAs NW growth with high growth rates. Since the initial alloying of the gold seeds with the substrate material plays a deciding role for the inceptive NW growth, InAs free standing nanowires were grown on GaAs(111)B substrate as well as on InAs/GaAs(111)B quasi-substrate. The influence of the MOVPE parameters will be discussed with respect to NW morphology and real-structure. A special focus will be set on the heteroepitaxial InAs NW growth on GaAs substrates. Gracing-incidence X-ray studies and transmission electron microscopy investigations revealed the existence of a thin Ga{sub x}In{sub 1-x}As graduated alloy layer with embedded crystalline gold alloy particles at the NW substrate interface. The effect of droplet composition on the VLS growth will be presented in a thermodynamic model.

Identification of Ina proteins from Fusarium acuminatum

Science.gov (United States)

Scheel, Jan Frederik; Kunert, Anna Theresa; Pöschl, Ulrich; Fröhlich-Nowoisky, Janine

2015-04-01

Freezing of water above -36° C is based on ice nucleation activity (INA) mediated by ice nucleators (IN) which can be of various origins. Beside mineral IN, biological particles are a potentially important source of atmospheric IN. The best-known biological IN are common plant-associated bacteria. The IN activity of these bacteria is induced by a surface protein on the outer cell membrane, which is fully characterized. In contrast, much less is known about the nature of fungal IN. The fungal genus Fusarium is widely spread throughout the earth. It belongs to the Ascomycota and is one of the most severe fungal pathogens. It can affect a variety of organisms from plants to animals including humans. INA of Fusarium was already described about 30 years ago and INA of Fusarium as well as other fungal genera is assumed to be mediated by proteins or at least to contain a proteinaceous compound. Although many efforts were made the precise INA machinery of Fusarium and other fungal species including the proteins and their corresponding genes remain unidentified. In this study preparations from living fungal samples of F. acuminatum were fractionated by liquid chromatography and IN active fractions were identified by freezing assays. SDS-page and de novo sequencing by mass spectrometry were used to identify the primary structure of the protein. Preliminary results show that the INA protein of F. acuminatum is contained in the early size exclusion chromatography fractions indicating a high molecular size. Moreover we could identify a single protein band from IN active fractions at 130-145 kDa corresponding to sizes of IN proteins from bacterial species. To our knowledge this is for the first time an isolation of a single protein from in vivo samples, which can be assigned as IN active from Fusarium.

U.S. Nonproliferation Policies and the Future of Nuclear Cooperation

International Nuclear Information System (INIS)

Kim, Byoung Jo; Lee, Sang Hyun

2008-12-01

In order for Korea to enhance nuclear cooperation with the U.S., the most urgent thing is to prove its nonproliferation commitment to international community, and legislate solid nonproliferation policies. To achieve these goals, Korean government need to consider to create Nonproliferation Task Force in the government and focus on proving Korea's firm commitment for nonproliferation. Along with it, as a civilian counterpart, Nonproliferation Research Center must be created as soon as possible to research, plan, and publicize Korea's nonproliferation policies and measures. At the same time, the government must set up a control tower that will coordinate Korea's nuclear diplomacy and guide proper division of labor among governmental and nongovernmental agencies in nonproliferation area. Finally, to raise general public's awareness about the danger of nuclear proliferation, government must invest on to develop educational programs and public relationship programs to educate the Korean public

The 50 Years of Safeguards and Non-Proliferation in Poland

International Nuclear Information System (INIS)

Pawlak, A.; Jurkowski, M.; Zagrajek, M.

2015-01-01

Milestones of safeguards and non-proliferation activities are presented. Poland has declared its compliance with non-proliferation regime by ratification of Treaty of Nonproliferation of Nuclear Weapons in 1969. Poland concluded in 1972 Agreement with IAEA for application of safeguards — INFCIRC/153. Next steps in implementation of international safeguards were: ratification of Additional Protocol and introduction of Integrated Safeguards. After accession to European Union, Poland fulfils its safeguards obligations according to following international legal instruments: Treaty establishing Euratom, Agreement between Poland, European Commission and International Atomic Energy Agency in connection with implementation of Article III of Treaty of Non-proliferation of Nuclear Weapons — INFCIRC/193 and Additional Protocol to this Agreement — INFCIRC/193 Add.8. Detailed safeguards requirements are established by domestic Act of Parliament of 29th November 2000 — Atomic law and European Union's Regulations of Commission (Euratom) No 302/2005 on application of Euratom safeguards and the Commission Recommendation on guidelines for the application of Regulation (Euratom) No 302/2005. SSAC was established in 1972 as required by CSA. Activities related to accounting for and control of nuclear material were conducted from 1970s till 1990s by Central Laboratory for Radiological Protection and National Inspectorate for Radiation and Nuclear Safety. Currently, NAEA is responsible for collecting and maintenance of accounting data and safeguards inspections at all MBAs. Around 30 routine inspections/year are performed by the NAEA, Euratom and IAEA. In addition, usually 2 unannounced inspections/year under framework of Integrated Safeguards are conducted. In accordance with implementation of Global Threat Reduction Initiative seven shipments of high enriched nuclear fuel from research reactor to Russian Federation under supervision of safeguards inspectors from NAEA

International scientific collaboration in nonproliferation

International Nuclear Information System (INIS)

Travelli, A.

1998-01-01

International collaboration is a vital component of every serious nonproliferation effort. Several examples of the experiences that the Argonne Arms Control and Nonproliferation Program has had in this area are given and, in the process, important components of the program come to light. Some of the main principles that the program has learned to follow while pursuing international collaboration projects are shared, as are the pitfalls that the program has learned to avoid. (author)

Electrical characterisation of Sn doped InAs grown by MOVPE

International Nuclear Information System (INIS)

Shamba, P.; Botha, L.; Krug, T.; Venter, A.; Botha, J.R.

2008-01-01

The feasibility of tetraethyl tin (TESn) as an n-type dopant for InAs is investigated. The electrical properties of Sn doped InAs films grown on semi-insulating GaAs substrates by MOVPE are extensively studied as a function of substrate temperature, V/III ratio, substrate orientation and TESn flow rate. Results from this study show that Sn concentrations can be controlled over 2 orders of magnitude. The Sn doped InAs layers exhibit carrier concentrations between 2.7 x 10 17 and 4.7 x 10 19 cm -3 with 77 K mobilities ranging from 12 000 to 1300 cm 2 /Vs. Furthermore, the influence of the variation of these parameters on the structural properties of InAs are also reported. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Strengthening the nuclear non-proliferation regime

International Nuclear Information System (INIS)

Carlson, J.

2003-01-01

Although the nuclear non-proliferation regime has enjoyed considerable success, today the regime has never been under greater threat. Three states have challenged the objectives of the NPT, and there is a technology challenge - the spread of centrifuge enrichment technology and know-how. A major issue confronting the international community is, how to deal with a determined proliferator? Despite this gloomy scenario, however, the non-proliferation regime has considerable strengths - many of which can be developed further. The regime comprises complex interacting and mutually reinforcing elements. At its centre is the NPT - with IAEA safeguards as the Treaty's verification mechanism. Important complementary elements include: restraint in the supply and the acquisition of sensitive technologies; multilateral regimes such as the CTBT and proposed FMCT; various regional and bilateral regimes; the range of security and arms control arrangements outside the nuclear area (including other WMD regimes); and the development of proliferation-resistant technologies. Especially important are political incentives and sanctions in support of non-proliferation objectives. This paper outlines some of the key issues facing the non-proliferation regime

Review of GAO report on the Nuclear Non-Proliferation Act of 1978. Hearing before the Committee on Foreign Affairs, House of Representatives, Ninety-Seventh Congress, First Session, May 21, 1981

International Nuclear Information System (INIS)

Anon.

1981-01-01

Three witnesses from the General Accounting Office (GAO) testified at a May 21, 1981 hearing on the results of a three-year review of the impact and implementation of the Nuclear Non-Proliferation Act (NNPA) of 1978. A total of 115 countries have ratified the Nuclear Non-Proliferation Treaty (NNPT), and some have urged a nuclear-weapons-free zone in Latin America. The GAO proposed recommendations for improving NNPA administration and developing a more coherent long-term policy. The GAO questions the need for additional enrichment capacity, and suggests a closer look at the need to complete the centrifuge facility. It notes only limited progress in multinational fuel-supply assurances and the establishment of international spent-fuel repositories. It urges the US to take a more-active role in these areas and in the international control system. A listing of US exports of highly enriched uranium from 1954 to 1981 follows the testimony

Nonproliferation Graduate Fellowship Program Annual Report: Class of 2011

Energy Technology Data Exchange (ETDEWEB)

McMakin, Andrea H.

2012-08-20

Annual report for the Nonproliferation Graduate Fellowship Program (NGFP), which PNNL administers for the National Nuclear Security Administration (NNSA). Features the Class of 2011. The NGFP is a NNSA program with a mission to cultivate future technical and policy leaders in nonproliferation and international security. Through the NGFP, outstanding graduate students with career interests in nonproliferation are appointed to program offices within the Office of Defense Nuclear Nonproliferation (DNN). During their one-year assignment, Fellows participate in programs designed to detect, prevent, and reverse the proliferation of nuclear weapons.

The future of non-proliferation

International Nuclear Information System (INIS)

Gere, F.

2000-01-01

This paper comprises two parts. The first part makes a status of the non-proliferation policy: problems of ratification of Start 2 and CTBT treaties, nuclear tests in India and Pakistan in May 1998 etc. The second part makes a prospective reflexion on the evolution of the position of nuclearized countries at the 2015-2030 vista: role of Asia, nuclear perception, evolution of the US perception of non-proliferation, military strategy and European unification. (J.S.)

Ag-catalyzed InAs nanowires grown on transferable graphite flakes

DEFF Research Database (Denmark)

Meyer-Holdt, Jakob; Kanne, Thomas; Sestoft, Joachim E.

2016-01-01

on exfoliated graphite flakes by molecular beam epitaxy. Ag catalyzes the InAs nanowire growth selectively on the graphite flakes and not on the underlying InAs substrates. This allows for easy transfer of the flexible graphite flakes with as-grown nanowire ensembles to arbitrary substrates by a micro...

International aspects of non-proliferation policy

International Nuclear Information System (INIS)

Aucoin, P.A.

1978-01-01

There are currently two areas on the national scene and one on the international scene that require immediate attention. The first is relief under contracts for enrichment services, an area in which the US can still demonstrate its desire to become a stable and continuous source of supply. The second national area is the Nuclear Non-Proliferation Act of 1977. The United States must proceed very cautiously, however, for if discretion and very careful judgment are not used, the Act will immediately be branded as a blatant effort on the part of the US to control the energy options of other sovereign states. The international area is that of the International Nuclear Fuel Cycle Evaluation program. This medium exists for wise and deliberate growth of a commercial nuclear power program which can serve the global community. The next three years probably allow one remaining chance for successful containment of weapons proliferation. If we do not recognize the rights of every sovereign state to voluntarily participate and agree, we, as members of the global community, will have failed

InAs nanowire formation on InP(001)

International Nuclear Information System (INIS)

Parry, H. J.; Ashwin, M. J.; Jones, T. S.

2006-01-01

The heteroepitaxial growth of InAs on InP(001) by solid source molecular beam epitaxy has been studied for a range of different growth temperatures and annealing procedures. Atomic force microscopy images show that nanowires are formed for deposition in the temperature range of 400-480 deg. C, and also following high temperature annealing (480 deg. C) after deposition at 400 deg. C. The wires show preferential orientation along and often exhibit pronounced serpentine behavior due to the presence of kinks, an effect that is reduced at increasing growth temperature. The results suggest that the serpentine behavior is related to the degree of initial surface order. Kinks in the wires appear to act as nucleation centers for In adatoms migrating along the wires during annealing, leading to the coexistence of large three-dimensional islands

U.S. nuclear non-proliferation policy: impact on exports and nuclear industry could not be determined. Report to the Congress

International Nuclear Information System (INIS)

1980-01-01

The Nuclear Non-Proliferation Act of 1978 established new measures to prevent the diversion to weapons use of peaceful nuclear exports. It also created a policy to confirm U.S. reliability as a nuclear supplier. GAO did not identify any export sales lost as a result of the Act, but did find indications that nonproliferation policies can influence export sales. Based on available data, GAO could not determine the impact of the Act on the competitiveness of U.S. nuclear exports. However, U.S. companies are at some disadvantage because importers perceive that implementation of the Act may result in delayed export licenses. The United States dominated the nuclear export market through the early 1970s. However, foreign competitors, some aided by U.S. technology transfers, emerged to monopolize home markets and compete for third-country business. Further, the market has been depressed since 1974 and prospects for U.S. nuclear power plant exports have dimmed greatly. However, U.S. companies continue to view exports as important to sustain production capacity

Growth of InAs Quantum Dots on Germanium Substrate Using Metal Organic Chemical Vapor Deposition Technique

Directory of Open Access Journals (Sweden)

Tyagi Renu

2009-01-01

Full Text Available Abstract Self-assembled InAs quantum dots (QDs were grown on germanium substrates by metal organic chemical vapor deposition technique. Effects of growth temperature and InAs coverage on the size, density, and height of quantum dots were investigated. Growth temperature was varied from 400 to 450 °C and InAs coverage was varied between 1.40 and 2.35 monolayers (MLs. The surface morphology and structural characteristics of the quantum dots analyzed by atomic force microscope revealed that the density of the InAs quantum dots first increased and then decreased with the amount of InAs coverage; whereas density decreased with increase in growth temperature. It was observed that the size and height of InAs quantum dots increased with increase in both temperature and InAs coverage. The density of QDs was effectively controlled by growth temperature and InAs coverage on GaAs buffer layer.

The year 2000 examination conference of the non-proliferation treaty and the future of the nuclear non-proliferation regime

International Nuclear Information System (INIS)

Grand, C.

2001-01-01

The nuclear weapons non-proliferation treaty (NPT), signed on July 1, 1968 and enforced on March 5, 1970, has been progressively considered as the headstone of the international non-proliferation and disarmament regime. The sixth NPT examination conference took place at New York (USA) in the year 2000, 5 years after the previous conference but also after the first nuclear weapon tests of India and Pakistan. This article recalls up the main non-proliferation events that took place between the 1995 and 2000 conferences and presents the progresses and results of the New York conference. Finally, it wonders about the ambiguities in the conclusions of this last conference. (J.S.)

Wet-chemical passivation of InAs: toward surfaces with high stability and low toxicity.

Science.gov (United States)

Jewett, Scott A; Ivanisevic, Albena

2012-09-18

In a variety of applications where the electronic and optical characteristics of traditional, siliconbased materials are inadequate, recently researchers have employed semiconductors made from combinations of group III and V elements such as InAs. InAs has a narrow band gap and very high electron mobility in the near-surface region, which makes it an attractive material for high performance transistors, optical applications, and chemical sensing. However, silicon-based materials remain the top semiconductors of choice for biological applications, in part because of their relatively low toxicity. In contrast to silicon, InAs forms an unstable oxide layer under ambient conditions, which can corrode over time and leach toxic indium and arsenic components. To make InAs more attractive for biological applications, researchers have investigated passivation, chemical and electronic stabilization, of the surface by adlayer adsorption. Because of the simplicity, low cost, and flexibility in the type of passivating molecule used, many researchers are currently exploring wet-chemical methods of passivation. This Account summarizes much of the recent work on the chemical passivation of InAs with a particular focus on the chemical stability of the surface and prevention of oxide regrowth. We review the various methods of surface preparation and discuss how crystal orientation affects the chemical properties of the surface. The correct etching of InAs is critical as researchers prepare the surface for subsequent adlayer adsorption. HCl etchants combined with a postetch annealing step allow the tuning of the chemical properties in the near-surface region to either arsenic- or indium-rich environments. Bromine etchants create indium-rich surfaces and do not require annealing after etching; however, bromine etchants are harsh and potentially destructive to the surface. The simultaneous use of NH(4)OH etchants with passivating molecules prevents contact with ambient air that can

Nuclear Society and non-proliferation problems

International Nuclear Information System (INIS)

Gagarinskij, A.Ya.; Kushnarev, S.V.; Ponomarev-Stepnoj, N.N.; Sukhoruchkin, V.K.; Khromov, V.V.; Shmelev, V.M.

1997-01-01

In the USSR Nuclear Society in 1991 the special working group on the problems of nuclear weapons non-proliferation and nuclear materials control, uniting the experts of different types (nuclear physicists, lawyers, teachers), was created. This group became the mechanism of the practical Nuclear Society activity realization in this sphere. Three milestones of the innovative activity can be specified. First Milestone. In January 1992 the Central Nuclear Society Board (of the International Public Nuclear Society Association) published a special appeal to the First Leaders of all countries - former USSR republics. This address paid a special attention to the unity of the USSR power-industrial complex, and numerous problems arisen while separating this complex, including nuclear weapons non-proliferation problems, were indicated as well. Second Milestone. In 1992 and 1993 the Nuclear Society experts issued two selection 'Nuclear Non-proliferation and Control Problems' including reviewing basic papers. In addition, materials on non-proliferation and control are published regularly in the organs. Third Milestone.In 1993 - 1997 some special scientific and technical events (conferences, workshops, meetings) allowing to analyze the joint international projects and contracts outcomes, and establish new contacts between the specialists of NIS, Baltic states and others, have been hold

Non-proliferation and security: synergy and differences

International Nuclear Information System (INIS)

Joly, J.

2013-01-01

Operators of nuclear facilities put in place both physical and organisational means to meet in a comprehensive way the requirements associated with Nuclear Non-Proliferation, Safety and Security. The common aim is to protect man and the environment from ionising radiation. The approaches for meeting these requirements have real similarities, but also differences which need to be respected in order to develop an appropriate synergy for obtaining the best possible level of safety, security and non-proliferation. This article aims to show the provisions that have been taken with regard to non-proliferation, security and safety which complement and reinforce each other.The paper is followed by the slides of the presentation. (author)

Twenty years of the Non-proliferation Treaty

International Nuclear Information System (INIS)

Goldblat, Jozef.

1990-01-01

The report assesses the achievements of the Non-proliferation Treaty (NPT) and discusses ways in which the non-proliferation regime could be strenghtened. It recommends a series of measures to be taken by the parties of the Treaty, both nuclear and non-nuclear weapons states, with a view to reinforcing the Treaty and achieving its universality. 198 refs

Canada and international safeguards. Verifying nuclear non-proliferation

International Nuclear Information System (INIS)

1990-01-01

The Non-Proliferation Treaty (NPT) came into force in 1970 and now has about 140 signatory nations. By creating legal barriers against proliferation and by promoting an international non-proliferation ethic, the NPT has promoted international peace and security. A key ingredient has been the confidence generated through verification by IAEA safeguards. By the end of 1988 IAEA safeguards agreements had been concluded with about 100 countries, including Canada. Over 500 nuclear facilities worldwide are under safeguards or contain safeguarded nuclear material. The existence of this credible and effective safeguards system makes international trade in nuclear equipment and materials possible, monitoring the transfer of nuclear technology to developing countries as well as between industrial countries. Canada is committed to non-proliferation and IAEA safeguards. Canadian non-proliferation policy is among the strictest in the world, even though opportunities have been lost to sell Canadian technology abroad as a result

Canada's nuclear non-proliferation policy

International Nuclear Information System (INIS)

1985-01-01

Canada's non-proliferation and safeguards policy has two objectives: 1) to promote the emergence of a more effective and comprehensive international non-proliferation regime; and 2) to assure the Canadian people and the international community that Canadian nuclear exports will not be used for any nuclear explosive purpose. By emphasizing the key role of the NPT, by promoting reliance upon and improvements in the IAEA safeguards system, by treating nuclear weapon and non-nuclear weapon states alike regarding Canadian nuclear exports, by working for new approaches covering the sensitive phases (e.g. reprocessing) of the nuclear fuel cycle, Canada's policy promotes attainment of the first objective. The latter objective is served through the network of bilateral nuclear agreements that Canada has put into place with its nuclear partners. Those agreements provide assurance that Canada's nuclear exports are used solely for legitimate, peaceful, nuclear energy production purposes. At the same time, Canada, having formulated its non-proliferation and safeguards policy during the period 1945 to 1980, has recognized that it has gone as far as it can on its own in this field and that from this point on any further changes should be made on the basis of international agreement. The Canadian objective in post-INFCE forums such as the Committee on Assurances of Supply is to exert Canada's best efforts to persuade the international community to devise a more effective and comprehensive international non-proliferation regime into which Canada and other suppliers might subsume their national requirements

China's position on nuclear non-proliferation

International Nuclear Information System (INIS)

Qian Jiadong.

1986-01-01

The paper discusses China's position on nuclear non-proliferation, in view of the fact that China does not subscribe to the Non-Proliferation Treaty (NPT). China refuses to accede to the NPT because it considers the treaty to be discriminatory, and reasons are given for this point of view. However its stand for nuclear disarmament and disapproval of nuclear proliferation are declared. Nuclear arms race, prevention of nuclear war, and nuclear disarmament are also considered. (UK)

Non-proliferation and safeguards aspects of alternative fuel cycle concepts

International Nuclear Information System (INIS)

Persiani, P.J.

1997-01-01

Timely visibility on the development, evaluation and optimization of fuel cycle concepts with respect to nonproliferation characteristics should be emphasized in the early stage of planning a civilian nuclear power program, by fuel cycle developers, reviewers and decision makers. Fuel cycle technologies have inherently differing levels of nonproliferation characteristic profiles. Institutional and/or multi-national arrangements have been effective in reducing the nonproliferation concerns. The implementation of international safeguards further reduces these concerns by the timely detection of a possible physical diversion of SNM from fuel cycle facilities. Fuel cycles are safeguardable, but the nonproliferation characteristics of fuel cycle concepts differ significantly with consequent impacts on the international level of technical safeguards measures. The paper comments on characteristics of some of the fuel cycle concepts for the purpose of exploring the need to develop advanced nonproliferation and safeguards measures. (author)

Electronic and optical properties of graphene-like InAs: An ab initio study

Science.gov (United States)

Sohrabi, Leila; Boochani, Arash; Ali Sebt, S.; Mohammad Elahi, S.

2018-03-01

The present work initially investigates structural, optical, and electronic properties of graphene-like InAs by using the full potential linear augmented plane wave method in the framework of density functional theory and is then compared with the bulk Indium Arsenide in the wurtzite phase. The lattice parameters are optimized with GGA-PBE and LDA approximations for both 2D- and 3D-InAs. In order to study the electronic properties of graphene-like InAs and bulk InAs in the wurtzite phase, the band gap is calculated by GGA-PBG and GGA-EV approximations. Moreover, optical parameters of graphene-like InAs and bulk InAs such as the real and imaginary parts of dielectric function, electron energy loss function, refractivity, extinction and absorption coefficients, and optical conductivity are investigated. Plasmonic frequencies of 2D- and 3D-InAs are also calculated by using maximum electron energy loss function and the roots of the real part of the dielectric function.

Optical emission of InAs nanowires

International Nuclear Information System (INIS)

Möller, M; De Lima Jr, M M; Cantarero, A; Chiaramonte, T; Cotta, M A; Iikawa, F

2012-01-01

Wurtzite InAs nanowire samples grown by chemical beam epitaxy have been analyzed by photoluminescence spectroscopy. The nanowires exhibit two main optical emission bands at low temperatures. They are attributed to the recombination of carriers in quantum well structures, formed by zincblende–wurtzite alternating layers, and to the donor–acceptor pair. The blue-shift observed in the former emission band when the excitation power is increased is in good agreement with the type-II band alignment between the wurtzite and zincblende sections predicted by previous theoretical works. When increasing the temperature and the excitation power successively, an additional band attributed to the band-to-band recombination from wurtzite InAs appears. We estimated a lower bound for the wurtzite band gap energy of approximately 0.46 eV at low temperature. (paper)

Optical emission of InAs nanowires

Science.gov (United States)

Möller, M.; de Lima, M. M., Jr.; Cantarero, A.; Chiaramonte, T.; Cotta, M. A.; Iikawa, F.

2012-09-01

Wurtzite InAs nanowire samples grown by chemical beam epitaxy have been analyzed by photoluminescence spectroscopy. The nanowires exhibit two main optical emission bands at low temperatures. They are attributed to the recombination of carriers in quantum well structures, formed by zincblende-wurtzite alternating layers, and to the donor-acceptor pair. The blue-shift observed in the former emission band when the excitation power is increased is in good agreement with the type-II band alignment between the wurtzite and zincblende sections predicted by previous theoretical works. When increasing the temperature and the excitation power successively, an additional band attributed to the band-to-band recombination from wurtzite InAs appears. We estimated a lower bound for the wurtzite band gap energy of approximately 0.46 eV at low temperature.

Nuclear non-proliferation

International Nuclear Information System (INIS)

Anon.

1990-01-01

This patent describes the treaty on the non-proliferation of nuclear weapons which is the corner-stone of an international non-proliferation regime which has grown to embrace the overwhelming majority of countries in the world in the period since the Treaty. The other elements of the regime include, first of all, the safeguards system of IAEA-which operates to prevent the diversion of nuclear materials to military or other prohibited activities and must be accepted by all non-nuclear-weapon parties to the Treaty and, secondly, the Antarctic Treaty, the Treaty for the Prohibition of Nuclear Weapons in Latin America (Treaty of Tlatelolco) and the south Pacific Nuclear Free zone Treaty (Treaty of Rarotonga)-which serve to extend the regime geographically. The last two Treaties require safeguards agreements with IAEA. In addition, the Treaty of Tlatelolco contains provisions establishing the agency for the Prohibition of Nuclear Weapons in Latin America and the Caribbean to ensure compliance

Development and current trends in the international nonproliferation regime

International Nuclear Information System (INIS)

Sessoms, A.L.

1984-01-01

The IAEA and its safeguards system is placed into a historical perspective. A personal perspective on the nonproliferation regime and on the Agency's role in it is then presented. This is done initially by discussing some of the landmark events in the history of the nonproliferation regime. Subsequently some of the history of arms control agreements and of the role of the IAEA are noted. Then political motivations of state and ways the Agency has an impact in the political nonproliferation sphere are addressed

United States non-proliferation policy

International Nuclear Information System (INIS)

Scheinman, L.

1978-01-01

U.S. non-proliferation policy is aimed at slowing the spread of nuclear weapons capabilities, managing the destabilizing effects of nuclear technology for energy purposes, and fostering international standards and institutions to deal responsibly with global nuclear development. These goals assume that nuclear technology has not already precluded social control and recognize the social benefits offered by peaceful uses of atomic energy. Non-proliferation policies recognize that the motivation for possessing nuclear weapons is a more-difficult problem than technical ability and will concentrate on reducing those incentives through international agreements and safeguards and by maintaining the separation of commercial nuclear fuel cycles and military uses

Jezdecké stezky v kraji Vysočina

OpenAIRE

Bendeová, Tereza

2014-01-01

This bachelor thesis discusses the topic of riding trails in the Vysočina region. At the beginning I discuss the role of equestrian tourism in the Czech Republic. There are briefly described origins and conditions of riding trails in the regions and also the list of the public support and grants for development of equestrian tourism. The next part focuses on chosen region and characterizes its natural and cultural heritage. There are also described several trails through the Vysočina region. ...

2. International conference on non-proliferation problems. Abstracts of reports

Energy Technology Data Exchange (ETDEWEB)

Koltysheva, G I; Perepelkin, I G [eds.

1999-12-31

On 14-17 September 1998, in Kurchatov (Kazakstan), II. International Conference on Non-proliferation Problems was held. Representatives from different international organizations (IAEA, UNO, CTBT Organization Preparatory Committee, Austria), from organizations of Kazakstan, Russia, USA, Japan took part in the Conference. At the conference there were 220 participants. Different issues relating to non-proliferation were discussed at the conference sections. The Conference included Plenary Session `History and Current State of Non-proliferation Problem` and three sections: (1) Practical measures to support non-proliferation regime and Control for Nuclear Tests`; (2) Problems on Eliminating Nuclear tests Consequences and Conversion of Nuclear and Industrial Complex`; (3) Medical and ecological problems of Nuclear Tests Consequences`

2. International conference on non-proliferation problems. Abstracts of reports

International Nuclear Information System (INIS)

Koltysheva, G.I.; Perepelkin, I.G.

1998-01-01

On 14-17 September 1998, in Kurchatov (Kazakstan), II. International Conference on Non-proliferation Problems was held. Representatives from different international organizations (IAEA, UNO, CTBT Organization Preparatory Committee, Austria), from organizations of Kazakstan, Russia, USA, Japan took part in the Conference. At the conference there were 220 participants. Different issues relating to non-proliferation were discussed at the conference sections. The Conference included Plenary Session 'History and Current State of Non-proliferation Problem' and three sections: 1) Practical measures to support non-proliferation regime and Control for Nuclear Tests'; 2) Problems on Eliminating Nuclear tests Consequences and Conversion of Nuclear and Industrial Complex'; 3) Medical and ecological problems of Nuclear Tests Consequences'

The Nuclear Non-Proliferation Policy of the Obama Administration

International Nuclear Information System (INIS)

Baek, Jin Hyun; Hwang, Ji Hwan

2009-12-01

The objective of this study is to analyze and foresee trends of international nuclear non-proliferation regimes focused on the nuclear non-proliferation policy of the Obama administration, and suggest national policy directions which promote utilization and development of nuclear energy in Korea. For the effective and efficient implementation of the national nuclear use and development program in current international nuclear environment, many efforts should be made: to actively and positively participate in the international nuclear non-proliferation regime; to strengthen nuclear diplomacy in a more systematic manner; and to strengthen the international nuclear cooperation

The European dimension in non-proliferation

International Nuclear Information System (INIS)

Krause, J.

1996-01-01

Europe was for decades the focal point of efforts to prevent or constrain nuclear proliferation and the first region in which non-proliferation efforts failed. Paper deals with current proliferation problems in Europe, namely, diversion of weapons, diversion from dismantling, production over-capacity, security concerns. Legal instruments against proliferation in Europe described here include development of international norms; instruments of security assurance and cooperation; disarmament assistance; fissile material management; assistance in creating export control systems; improving and harmonizing export controls for dual-purpose items. Problems in implementing non-proliferation instruments are described separately

Hall and thermoelectric evaluation of p-type InAs

Energy Technology Data Exchange (ETDEWEB)

Wagener, M.C., E-mail: magnus.wagener@nmmu.ac.z [Department of Physics, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa); Wagener, V.; Botha, J.R. [Department of Physics, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa)

2009-12-15

This paper compares the galvanometric and thermoelectric evaluation of the electrical characteristics of narrow gap semiconductors. In particular, the influence of a surface inversion layer is incorporated into the analysis of the temperature-dependent Hall and thermoelectric measurements of p-type InAs. The temperature at which the Seebeck coefficient of p-type material changes sign is shown to be unaffected by the presence of degenerate conduction paths. This finding consequently facilitated the direct determination of the acceptor density of lightly doped thin film InAs.

Hall and thermoelectric evaluation of p-type InAs

International Nuclear Information System (INIS)

Wagener, M.C.; Wagener, V.; Botha, J.R.

2009-01-01

This paper compares the galvanometric and thermoelectric evaluation of the electrical characteristics of narrow gap semiconductors. In particular, the influence of a surface inversion layer is incorporated into the analysis of the temperature-dependent Hall and thermoelectric measurements of p-type InAs. The temperature at which the Seebeck coefficient of p-type material changes sign is shown to be unaffected by the presence of degenerate conduction paths. This finding consequently facilitated the direct determination of the acceptor density of lightly doped thin film InAs.

Heavy water and nonproliferation

International Nuclear Information System (INIS)

Miller, M.M.

1980-05-01

This report begins with a historical sketch of heavy water. The report next assesses the nonproliferation implications of the use of heavy water-moderated power reactors; several different reactor types are discussed, but the focus is on the natural uranium, on-power fueled, pressure tube reactor CANDU. The need for and development of on-power fueling safeguards is discussed. Also considered is the use of heavy water in plutonium production reactors as well as the broader issue of the relative nuclear leverage that suppliers can bring to bear on countries with natural uranium-fueled reactors as compared to those using enriched designs. The final chapter reviews heavy water production methods and analyzes the difficulties involved in implementing these on both a large and a small scale. It concludes with an overview of proprietary and nonproliferation constraints on heavy water technology transfer

Nuclear exports and non-proliferation

International Nuclear Information System (INIS)

Courteix, Simone.

1978-01-01

Increased preoccupation in present times with the risk of proliferation of nuclear weapons is reflected in the multiplication of international agreements such as the Non-proliferation Treaty and in the strengthening of consultations between industrialised countries (London Club). After analysing the IAEA safeguards system under the Non-proliferation Treaty and its shortcomings both technically and otherwise, the author considers how this situation can be remedied in the light of the London Agreements and in view of the position of the main countries concerned. The annex to the book contains the texts of many international agreements and relevant national regulations as well as nuclear policy statements. It also includes a detailed bibliograaphy. (NEA) [fr

Spin effects in InAs self-assembled quantum dots

Directory of Open Access Journals (Sweden)

Brasil Maria

2011-01-01

Full Text Available Abstract We have studied the polarized resolved photoluminescence in an n-type resonant tunneling diode (RTD of GaAs/AlGaAs which incorporates a layer of InAs self-assembled quantum dots (QDs in the center of a GaAs quantum well (QW. We have observed that the QD circular polarization degree depends on applied voltage and light intensity. Our results are explained in terms of the tunneling of minority carriers into the QW, carrier capture by InAs QDs and bias-controlled density of holes in the QW.

On the non-proliferation framework of Japan's peaceful nuclear utilization program

International Nuclear Information System (INIS)

Kano, Takashi

1996-01-01

The Conference of the States Party to the Treaty on the Non-proliferation of Nuclear Weapons (hereinafter referred to as the NPT) convened in New York, from April 17 to May 12, 1995 and decided that the NPT shall continue in force indefinitely, after reviewing the operation and affirming some aspects of the NPT, while emphasizing the ''Decision on Strengthening the Review Process'' for the NPT and the ''Decision on Principles and Objectives for Nuclear Non-proliferation and Disarmament,'' also adopted by the Conference. In parallel, Japan made its basic non-proliferation policy clear in the ''Long-Term Program for Research, Development and Utilization of Nuclear Energy'' which was decided by the Atomic Energy Commission (chaired by Mikio Oomi, then Minister of the Science and Technology Agency of Japan) in June 1994. The Long-Term Program discusses various problems facing post-Cold-War international society and describes Japan's policy for establishing international confidence concerning non-proliferation. This paper summarizes Japan's non-proliferation policy as articulated in the Long-Term Program, and describes some results of an analysis comparing the Long-Term Program with the resolutions on the international non-proliferation frameworks adopted by the NPT conference

20 CFR 668.710 - What planning documents must an INA grantee submit?

Science.gov (United States)

2010-04-01

... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false What planning documents must an INA grantee... Planning/Funding Process § 668.710 What planning documents must an INA grantee submit? Each grantee... participant services and expenditures covering the two-year planning cycle. We will, in consultation with the...

A soft lithographic approach to fabricate InAs nanowire field-effect transistors

DEFF Research Database (Denmark)

Madsen, Morten; Lee, S. H.; Shin, S.-H.

2018-01-01

-down approach and an epitaxial layer transfer process, using MBE-grown ultrathin InAs as a source wafer. The width of the InAs nanowires was controlled using solvent-assisted nanoscale embossing (SANE), descumming, and etching processes. By optimizing these processes, NWs with a width less than 50 nm were...

Non-proliferation aspects of long term assurance of supply

International Nuclear Information System (INIS)

1978-01-01

The meetings in this section deal with the non-proliferation aspects of long-term assurance of supply of the nuclear fuel cycle. A list of 12 fundamental questions concerning the observation and application of the non-proliferation regulations is followed by the comments made by representatives of 10 countries

A Digest of Nonproliferation Literature.

Energy Technology Data Exchange (ETDEWEB)

Duggan, Ruth A

2006-04-01

In preparation for the 2005 US/Russian Weapons Laboratories Directors Meeting, the six laboratories participating in the meeting endeavored to develop a strategy for nonproliferation technology research and development. A literature review was conducted to identify possible areas of technical collaboration and technology opportunities associated with improving nonproliferation associated with the civilian nuclear fuel cycle. The issue of multinationalization of the nuclear fuel cycle was also researched. This digest is the compilation of one-page summaries used by management of the three US nuclear weapons laboratories in preparation for strategy development. Where possible, the Web site address of the complete paper is referenced.3 AcknowledgementsThe author wishes to thank Jessica Ruyle, Nancy Orlando-Gay, and Barbara Dry for their research assistance and contributions.4

Nonproliferation characteristics of advanced fuel cycle concepts

International Nuclear Information System (INIS)

Persiani, P.J.

1998-01-01

The purpose of this study is to comment on the proliferation characteristic profiles of some of the proposed fuel cycle alternatives to help ensure that nonproliferation concerns are introduced into the early stages of a fuel cycle concept development program, and to perhaps aid in the more effective implementation of the international nonproliferation regime initiatives and safeguards methods and systems. Alternative cycle concepts proposed by several countries involve the recycle of spent fuel without the separation of plutonium from uranium and fission products

The Office of Safeguards and Security Nonproliferation Support Program

International Nuclear Information System (INIS)

Desmond, W.J.

1996-01-01

The Nonproliferation Support Program was established in the Department of Energy, Office of Safeguards and Security on october 1, 1995. its mission includes providing assistance to Departmental efforts for improved international material protection, control and accounting programs by coordinating and leveraging domestic safeguards and security policy, practice and experience into the international arena. A major objective of the program is to balance US national security requirements with global support of the nonproliferation objectives. This paper describes the organization of the Office of Safeguards and Security and the Nonproliferation Support Program role and responsibility, and presents some of the current areas of program emphasis and activity

Special Issue on University Nonproliferation Education and Training Introduction

International Nuclear Information System (INIS)

Leek, K.M.

2006-01-01

Nonproliferation, like many aspects of security, has not played out as many expected following the end of the cold war. The peace dividend has been elusive in many countries. The notion that the world would become a safer and more secure place as nuclear weapons stockpiles were reduced has been trumped by the rise in international terrorism. Hopes that nuclear weapons would lose their salience as markers of elite status among nations along with pressures to acquire them have been dashed. The drive by some countries and terrorist groups to acquire nuclear weapons has not diminished, and the threat of proliferation has increased. At the level of the nation state, the Nonproliferation Treaty (NPT) itself is under pressure as more nations acquire nuclear weapons, de facto weapons states fail to join, and nations that want to acquire them leave or threaten to leave. At the sub-state level, the convergence of terrorism and weapons of mass destruction (WMD) has introduced an element of uncertainty into nonproliferation that is unprecedented. Another feature of the post-cold war era that has taken many by surprise is the continued, and growing need for trained specialists in nonproliferation and nuclear materials management. Contained within the notion of disarmament and reduced strategic importance of nuclear weapons was the expectation of a diminishing workforce of trained nonproliferation and nuclear materials specialists. Events have overtaken this assumption.

U.S. nonproliferation policy in the decade of the eighties: Past dilemmas and prospects for the future

International Nuclear Information System (INIS)

Marshall, H.R. Jr.

1986-01-01

No single event had more effect on the policies concerning nuclear importation and exportation activities than the 1974 detonation of a nuclear explosive device in India. This led eventually to the enactment of the Nuclear Non-Proliferation Act (NNPA) in 1978. The author describes the difficult negotiations of the U.S. administration with Euratom, Japan, China, and Latin America. (CW) [de

Academic perspectives on the non-proliferation problem

International Nuclear Information System (INIS)

Gummett, P.

1984-01-01

The USA has demonstrated a greater penchant for a technical focus aimed at denial than any other state, despite a brief interlude under President Nixon and Dr. Kissinger when it displayed a total lack of concern about proliferation. This terminated with the sudden reawakening of interest following the Indian explosion and the announcement that the USA was not prepared to accept additional requests for uranium-enrichment services. According to Brenner, this enrichment crisis was engineered as a deliberate act of policy: yet this act of policy was unrelated to non-proliferation objectives. Rather, the Nixon administration's interest in privatisation in general, and commercialisation of enriched-uranium supply in particular, had led to a bureaucratic battle between the domestic side of the White House, the Atomic Energy Commission (AEC) and the Joint Committee on Atomic Energy (JCAE). This battle was totally unrelated to foreign policy: a situation not without precedent in this area. Nixon's Republican administration deliberately provoked a supply bottleneck by changing the terms of AEC supply contracts, with the intention of forcing the Democrat-dominated JCAE to agree to the entry of private industry into the uranium-enrichment business. The outcome was more dramatic than had been intended

Formation of nanogaps in InAs nanowires by selectively etching embedded InP segments.

Science.gov (United States)

Schukfeh, M I; Storm, K; Hansen, A; Thelander, C; Hinze, P; Beyer, A; Weimann, T; Samuelson, L; Tornow, M

2014-11-21

We present a method to fabricate nanometer scale gaps within InAs nanowires by selectively etching InAs/InP heterostructure nanowires. We used vapor-liquid-solid grown InAs nanowires with embedded InP segments of 10-60 nm length and developed an etching recipe to selectively remove the InP segment. A photo-assisted wet etching process in a mixture of acetic acid and hydrobromic acid gave high selectivity, with accurate removal of InP segments down to 20 nm, leaving the InAs wire largely unattacked, as verified using scanning electron and transmission electron microscopy. The obtained nanogaps in InAs wires have potential as semiconducting electrodes to investigate electronic transport in nanoscale objects. We demonstrate this functionality by dielectrophoretically trapping 30 nm diameter gold nanoparticles into the gap.

Formation of nanogaps in InAs nanowires by selectively etching embedded InP segments

International Nuclear Information System (INIS)

Schukfeh, M I; Hansen, A; Tornow, M; Storm, K; Thelander, C; Samuelson, L; Hinze, P; Weimann, T; Beyer, A

2014-01-01

We present a method to fabricate nanometer scale gaps within InAs nanowires by selectively etching InAs/InP heterostructure nanowires. We used vapor–liquid–solid grown InAs nanowires with embedded InP segments of 10–60 nm length and developed an etching recipe to selectively remove the InP segment. A photo-assisted wet etching process in a mixture of acetic acid and hydrobromic acid gave high selectivity, with accurate removal of InP segments down to 20 nm, leaving the InAs wire largely unattacked, as verified using scanning electron and transmission electron microscopy. The obtained nanogaps in InAs wires have potential as semiconducting electrodes to investigate electronic transport in nanoscale objects. We demonstrate this functionality by dielectrophoretically trapping 30 nm diameter gold nanoparticles into the gap. (paper)

Effect of growth temperature on the morphology and phonon properties of InAs nanowires on Si substrates

Directory of Open Access Journals (Sweden)

Lei Wen

2011-01-01

Full Text Available Abstract Catalyst-free, vertical array of InAs nanowires (NWs are grown on Si (111 substrate using MOCVD technique. The as-grown InAs NWs show a zinc-blende crystal structure along a < 111 > direction. It is found that both the density and length of InAs NWs decrease with increasing growth temperatures, while the diameter increases with increasing growth temperature, suggesting that the catalyst-free growth of InAs NWs is governed by the nucleation kinetics. The longitudinal optical and transverse optical (TO mode of InAs NWs present a phonon frequency slightly lower than those of InAs bulk materials, which are speculated to be caused by the defects in the NWs. A surface optical mode is also observed for the InAs NWs, which shifts to lower wave-numbers when the diameter of NWs is decreased, in agreement with the theory prediction. The carrier concentration is extracted to be 2.25 × 1017 cm-3 from the Raman line shape analysis. A splitting of TO modes is also observed. PACS: 62.23.Hj; 81.07.Gf; 63.22.Gh; 61.46.Km

The year 2000 examination conference of the non-proliferation treaty and the future of the nuclear non-proliferation regime; La conference d'examen 2000 du TNP et l'avenir du regime de non-proliferation nucleaire

Energy Technology Data Exchange (ETDEWEB)

Grand, C. [Institut d' Etudes Politiques de Paris, 75 (France); Ecole Speciale Militaire de Saint-Cyr-Coetquidan (France)

2001-07-01

The nuclear weapons non-proliferation treaty (NPT), signed on July 1, 1968 and enforced on March 5, 1970, has been progressively considered as the headstone of the international non-proliferation and disarmament regime. The sixth NPT examination conference took place at New York (USA) in the year 2000, 5 years after the previous conference but also after the first nuclear weapon tests of India and Pakistan. This article recalls up the main non-proliferation events that took place between the 1995 and 2000 conferences and presents the progresses and results of the New York conference. Finally, it wonders about the ambiguities in the conclusions of this last conference. (J.S.)

Metalorganic vapour epitaxial growth and infrared characterisation of InAsSb and InAs on InAs substrates

CSIR Research Space (South Africa)

Baisitse, TR

2006-07-01

Full Text Available Motivation for the research: Interest exists in III-V semiconducting materials (InAs, GaSb, InSb and related alloys) for the detection of infrared radiation; Such materials could be used as alternatives for future infrared detectors and various...

Nuclear non-proliferation: failures and prospects

International Nuclear Information System (INIS)

Imai, R.; Press, R.

1980-01-01

The objective of this paper is to examine the evolution of combined political and technical attempts to achieve worldwide acceptance of a commitment to non-proliferation, to note failures to date, and to identify essential factors to be satisfied if greater and necessary success is to be achieved in the immediate future. For this it is necessary to separate the realism and unrealism so often involved in discussing the concept of non-proliferation, as defined above, particularly if treated as a moral principle rather than as part of a general security issue reflecting shifts in regional and global stability. The political nature of the non-proliferation problem is underlined by the fact that whereas five nuclear weapon states are currently accepted, any threatened increase in that number is discouraged by every possible peaceful means. This fact combines political acceptance of an existing international situation with a belief that any addition to the present number must lead to international instability. Success in preventing additions may be more readily achieved through political understanding and perhaps some compromises, in particular cases, rather than through seeking a universal solution to a generalized problem

Wavelength tuning of InAs quantum dots grown on InP (100) by chemical-beam epitaxy

International Nuclear Information System (INIS)

Gong, Q.; Noetzel, R.; Veldhoven, P.J. van; Eijkemans, T.J.; Wolter, J.H.

2004-01-01

We report on an effective way to continuously tune the emission wavelength of InAs quantum dots (QDs) grown on InP (100) by chemical-beam epitaxy. The InAs QD layer is embedded in a GaInAsP layer lattice matched to InP. With an ultrathin GaAs layer inserted between the InAs QD layer and the GaInAsP buffer, the peak wavelength from the InAs QDs can be continuously tuned from above 1.6 μm down to 1.5 μm at room temperature. The major role of the thin GaAs layer is to greatly suppress the As/P exchange during the deposition of InAs and subsequent growth interruption under arsenic flux, as well as to consume the segregated surface In layer floating on the GaInAsP buffer layer

Positioning of self-assembled InAs quantum dots by focused ion beam implantation

International Nuclear Information System (INIS)

Mehta, M.

2007-01-01

Self-assembled quantum dots (QDs) are envisioned as building blocks for realization of novel nanoelectronic devices, for which the site-selective growth is highly desirable. This thesis presents a successful route toward selective positioning of self-assembled InAs QDs on patterned GaAs surface by combination of in situ focused ion beam (FIB) implantation and molecular beam epitaxy (MBE) technology. First, a buffer layer of GaAs was grown by MBE before a square array of holes with a pitch of 1-2 μm was fabricated by FIB implantation of Ga and In, ions respectively. Later, an in-situ annealing step followed by InAs deposition was performed. The InAs QDs were preferentially formed in the holes generated by FIB. The influence of ion dose, annealing parameters and InAs amount was investigated in this work. With optimized parameters, more than 50 % single dot occupancy per hole is achieved. Furthermore, the photoluminescence spectra from positioned QDs confirm their good optical quality. (orig.)

20 CFR 668.650 - Can INA grantees exclude segments of the eligible population?

Science.gov (United States)

2010-04-01

... eligible population? 668.650 Section 668.650 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION... population? (a) No, INA grantees cannot exclude segments of the eligible population. INA grantees must document in their Two Year Plan that a system is in place to afford all members of the eligible population...

Safeguards and non-proliferation: current challenges and the implications for Australia

International Nuclear Information System (INIS)

Leask, A.; Carlson, J.

2006-01-01

Full text: The expansion of nuclear programs raises the issue of how to ensure this does not increase the risk of nuclear weapons proliferation. The non-proliferation regime - based on the NPT and its verification mechanism, the IAEA safeguards system - has been developed to provide assurance that nuclear programs are exclusively peaceful. Although to date the non-proliferation regime has been remarkably successful, in recent years it has come under serious challenge. Nuclear proliferation is emerging as one of the major issues facing the international community. Addressing technical and institutional aspects of the non-proliferation regime - especially safeguards, but also complementary measures such as export controls, proliferation-resistant technology, and an international framework on sensitive technology - is important. But proliferation is a political problem, and ultimately the success of the non-proliferation regime depends on political resolve to uphold compliance, using incentives and if necessary sanctions. These issues are vitally important to Australia's future. Being a major uranium supplier has strengthened Australia's influence in non-proliferation and safeguards developments

Sustaining non-proliferation in the 1980s

International Nuclear Information System (INIS)

Nye, J.S.

1984-01-01

The subject is discussed as follows: introduction; the non-proliferation regime - 1950s to 1970s (IAEA safeguards; Non-proliferation Treaty; oil crisis; proposed sale of facilities for producing weapons-usable materials; USA position); the Carter Administration approach; INFCE (International Nuclear Fuel Cycle Evaluation); incentives (USA); export legislation (USA); domestic breeder policy (USA); maintaining the regime in the 1980s (safeguards; Pu and highly enriched uranium management; international spent fuel storage; fuel assurances); the problem of priority; rate vs. degree of proliferation; relations among regimes (international regimes); conclusion. (U.K.)

Growth-interruption-induced low-density InAs quantum dots on GaAs

International Nuclear Information System (INIS)

Li, L. H.; Alloing, B.; Chauvin, N.; Fiore, A.; Patriarche, G.

2008-01-01

We investigate the use of growth interruption to obtain low-density InAs quantum dots (QDs) on GaAs. The process was realized by Ostwald-type ripening of a thin InAs layer. It was found that the optical properties of the QDs as a function of growth interruption strongly depend on InAs growth rate. By using this approach, a low density of QDs (4 dots/μm 2 ) with uniform size distribution was achieved. As compared to QDs grown without growth interruption, a larger energy separation between the QD confined levels was observed, suggesting a situation closer to the ideal zero-dimensional system. Combining with an InGaAs capping layer such as In-rich QDs enable 1.3 μm emission at 4 K

Nonproliferation Education at the University of Washington

International Nuclear Information System (INIS)

Jones, Chris D.; Leek, K.M.

2006-01-01

The nonproliferation curriculum at the University of Washington (UW) is the product of collaboration between Pacific Northwest Center for Global Security (PNWCGS) at the Pacific Northwest National Laboratory (PNNL) and the Jackson School of International Studies (JSIS) and Department of Political Science at the University of Washington. This collaboration began in 2001 with the establishment the Institute for Global and Regional Security Studies (IGRSS). IGRSS is housed in the Jackson School, which will celebrate its centenary in 2008 as a center for the study of world regions. PNNL also engages in a number of collaborative relationships with UW units in the natural and applied sciences. The principal goal of IGRSS has been to develop courses that draw graduates and undergraduates into careers in the field of nonproliferation. Since offering its first courses in 2002, IGRSS has assisted a substantial number of UW graduate students in submitting successful applications for nonproliferation positions in U.S. government agencies, including the Nonproliferation Graduate Program at the National Nuclear Security Administration. Since 2001, several UW undergraduates have begun careers in the field of nonproliferation, either by working at national laboratories or enrolling in non-UW graduate programs. The UW brought to its nonproliferation partnership with PNNL long-established programs in a wide range of professional programs and academic disciplines, including the 14 interdisciplinary regional and topical programs of the Jackson School of International Studies. The JSIS is an interdisciplinary and interdepartmental enterprise that brings together faculty and students from across the UW. Since the late 1940s the UW has trained experts for the nation's foreign policy community in programs focused in the languages, cultures, and histories of regions deemed critical to U.S. national security. However, since the termination of its program in nuclear engineering several

Nuclear disarmament. Options for the coming non-proliferation treaty surveillance cycle

International Nuclear Information System (INIS)

Mueller, Harald

2011-01-01

The report is aimed on the nuclear disarmament discussion with respect to the disagreement of nuclear weapon states and those without nuclear weapons, esp. the non-aligned movement (NAM) concerning the non-proliferation treaty. The report covers the following issues: The role of the non-proliferation treaty, nuclear disarmament in the last surveillance conference 2010, the different disarmament philosophies, the possibilities of bridging the disagreement, further disarmament options for the future non-proliferation treaty surveillance cycle, German options for the future surveillance cycle.

Awareness of the Vysočina Regional Food Labels With Context of Their Media Presence

Directory of Open Access Journals (Sweden)

Martina Chalupová

2016-01-01

Full Text Available The article presents results of research study that focused on the recognition of the Vysočina regional labels among the consumers in the region in connection with media analysis about the topic. Research among consumers was conducted in each district of Vysočina Region (Jihlava, Žďár nad Sázavou, Třebíč, Havlíčkův Brod and Pelhřimov by interviewing a sample of 819 respondents, selected by quota sampling methods. The research was aimed at analysing the ability of respondents to recognise and differentiate two existing regional labels VYSOČINA Regional Product®, Regional Food Vysočina Region and also nonexistent brand From Our Region Vysočina, created by authors. Data have been processed with correspondence analysis and showed that respondents connect different characteristics with the labels. Media analysis of the Vysočina regional labels revealed that media may help building awareness about the labels but they do not shape respondents’ views on them. Examining the link between the frequency of different types of information in media and their potential impact on the labels’ pereception by consumers have shown distorted image. Stronger consensus between research and media analysis have been examined only on importance of products’ origin, which can be viewed as a logical inference from the name of the labels.

Synergies between nonproliferation regimes: A pragmatic approach

International Nuclear Information System (INIS)

Findlay, Trevor; Meier, Oliver

2001-01-01

Full text: With the recent progress in establishing international nonproliferation regimes, the question of synergies between different verification and monitoring regimes is becoming more acute. Three multilateral and universal nonproliferation organisations covering safeguards on civil nuclear materials, nuclear testing, and chemical weapons are up and running. A regime on biological weapons is under negotiation. Several regional organisations concerned with monitoring nonproliferation commitments in the nuclear field are in place; others are being established. Past discussions on synergies between these regimes have suffered from being too far-reaching. These discussions often have not reflected adequately the political difficulties of cooperation between regimes with different membership, scope and institutional set-up. This paper takes a pragmatic look at exploiting synergies and identifies some potential and real overlaps in the work between different verification regimes. It argues for a bottom-up approach and identifies building blocks for collaboration between verification regimes. By realising such, more limited potential for cooperation, the ground could be prepared for exploiting other synergies between these regimes. (author)

From nuclear non-proliferation to nuclear disarmament: a need to refocus NPT priorities

International Nuclear Information System (INIS)

Sethi, Manpreet

1998-01-01

This paper seeks to suggest that attempts at general and complete nuclear disarmament have largely failed because of an over emphasis on nuclear non-proliferation, particularly horizontal, while disarmament has attracted only lip service from the perpetrators of nuclear weapons. In this regard, the treaty of the Non-Proliferation of Nuclear Weapons (NPT) that is deemed to be the core of the global non-proliferation regime is no less to blame for having indulged in a skewed pursuit of its twin objectives - nuclear non-proliferation and nuclear disarmament. The paper argues that nuclear non-proliferation can be sustainable only if complemented by nuclear disarmament. In the absence of the latter, proliferation of nuclear weapons, irrespective of the NPT and its safeguards regime, would always pose a potential risk

Modeling and Simulation for Safeguards and Nonproliferation Workshop

Energy Technology Data Exchange (ETDEWEB)

Gilligan, Kimberly V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kirk, Bernadette Lugue [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-01-01

The Modeling and Simulation for Safeguards and Nonproliferation Workshop was held December 15–18, 2014, at Oak Ridge National Laboratory. This workshop was made possible by the Next Generation Safeguards Initiative Human Capital Development (NGSI HCD) Program. The idea of the workshop was to move beyond the tried-and-true boot camp training of nonproliferation concepts to spend several days on the unique perspective of applying modeling and simulation (M&S) solutions to safeguards challenges.

Non-proliferation

International Nuclear Information System (INIS)

Manley, I.T.

1981-01-01

Proliferation is a problem that can only be solved when the political problems which lead countries to contemplate, the possession of nuclear weapons are solved; in the meantime it can only be managed. Non-proliferation policy has to deal both with the political and the technical aspects of proliferation. It must seek to buy time by addressing the reasons why nations feel the political need to construct nuclear weapons, as well as delaying the moment when such nations feel capable of doing so. The subject is examined and proposals made. (author)

Nuclear Activities (Prohibitions) Act 1983

International Nuclear Information System (INIS)

1983-01-01

The purpose of this Act is to protect the health and safety of the people of Victoria and its environment by prohibiting nuclear activities from being carried out and regulating the possession of certain nuclear material in a manner consistent with assisting Australia in meeting its international nuclear non-proliferation objectives. (NEA) [fr

British nuclear non-proliferation policy and the trident purchase

International Nuclear Information System (INIS)

Keohane, D.

1984-01-01

Since the mid-1950s, the UK has had a policy of making significant and sustained efforts to minimise the spread of nuclear arms. Unlike the global focus of its non-proliferation policy, the decision on Trident in centred upon national and perhaps regional requirements. At a time when non-nuclear countries are charging nuclear-weapon states with a grave failure to meet their obligations under Article VI of the NPT, Britain is making plans that would further increase the gap between the nuclear 'haves' and have-nots' and that indicate it expects to require nuclear arms in the next century. It would of course be unrealistic to expect a government to fully harmonise its manifold policies and unreasonable to suggest it should give absolute priority to one of its policy concerns, such as non-proliferation. But Britain is emphasising the high value it places upon the independent possession of strategic nuclear arms through its decision to purchase Trident, thus implicitly contradicting the logic underlying its non-proliferation policy. Compared to other factors, the influence of the Trident decision upon the non-proliferation regime appears very marginal, yet it is unlikely to strengthen that regime

InAs quantum dots as charge storing elements for applications in flash memory devices

Energy Technology Data Exchange (ETDEWEB)

Islam, Sk Masiul; Biswas, Pranab [Materials Science Centre, Indian Institute of Technology, Kharagpur 721 302 (India); Banerji, P., E-mail: pallab@matsc.iitkgp.ernet.in [Materials Science Centre, Indian Institute of Technology, Kharagpur 721 302 (India); Chakraborty, S. [Applied Materials Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Sector-I, Kolkata 700 064 (India)

2015-08-15

Graphical abstract: - Highlights: • Catalyst-free growth of InAs quantum dots was carried out on high-k ZrO{sub 2}. • Memory device with InAs quantum dots as charge storage nodes are fabricated. • Superior memory window, low leakage and reasonably good retention were observed. • Carrier transport phenomena are explained in both program and erase operations. - Abstract: InAs quantum dots (QDs) were grown by metal organic chemical vapor deposition technique to use them as charge storage nodes. Uniform QDs were formed with average diameter 5 nm and height 5–10 nm with a density of 2 × 10{sup 11} cm{sup −2}. The QDs were grown on high-k dielectric layer (ZrO{sub 2}), which was deposited onto ultra-thin GaP passivated p-GaAs (1 0 0) substrate. A charge storage device with the structure Metal/ZrO{sub 2}/InAs QDs/ZrO{sub 2}/(GaP)GaAs/Metal was fabricated. The devices containing InAs QDs exhibit superior memory window, low leakage current density along with reasonably good charge retention. A suitable electronic band diagram corresponding to programming and erasing operations was proposed to explain the operation.

Development of Computer-Aided Learning Programs on Nuclear Nonproliferation and Control

International Nuclear Information System (INIS)

Kim, Hyun Chul

2011-01-01

The fulfillment of international norms for nuclear nonproliferation is indispensable to the promotion of nuclear energy. The education and training for personnel and mangers related to the nuclear material are one of crucial factors to avoid unintended non-compliance to international norms. Korea Institute of Nuclear Nonproliferation and Control (KINAC) has been providing education and training on nuclear control as its legal duty. One of the legally mandatory educations is 'nuclear control education' performed since 2006 for the observation of the international norms on nuclear nonproliferation and the spread of the nuclear control culture. The other is 'physical protection education' performed since 2010 for maintaining the national physical protection regime effectively and the spread of the nuclear security culture. The 2010 Nuclear Security Summit was held in Washington, DC to enhance international cooperation to prevent nuclear terrorism. During the Summit, the South Korea was chosen to host the second Nuclear Summit in 2012. South Korean President announced that South Korea would share its expertise and support the Summit's mission by setting up an international education and training center on nuclear security in 2014. KINAC is making a full effort to set up the center successfully. An important function of the center is education and training in the subjects of nuclear nonproliferation, nuclear safeguards, nuclear security, and nuclear export/import control. With increasing importance of education and training education on nuclear nonproliferation and control, KINAC has been developing computer-aided learning programs on nuclear nonproliferation and control to overcome the weaknesses in classroom educations. This paper shows two learning programs. One is an e-learning system on the nuclear nonproliferation and control and the other is a virtual reality program for training nuclear material accountancy inspection of light water reactor power plants

Development of Computer-Aided Learning Programs on Nuclear Nonproliferation and Control

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyun Chul [Korea Institute of Nuclear Nonproliferation and Control, Daejeon (Korea, Republic of)

2011-10-15

The fulfillment of international norms for nuclear nonproliferation is indispensable to the promotion of nuclear energy. The education and training for personnel and mangers related to the nuclear material are one of crucial factors to avoid unintended non-compliance to international norms. Korea Institute of Nuclear Nonproliferation and Control (KINAC) has been providing education and training on nuclear control as its legal duty. One of the legally mandatory educations is 'nuclear control education' performed since 2006 for the observation of the international norms on nuclear nonproliferation and the spread of the nuclear control culture. The other is 'physical protection education' performed since 2010 for maintaining the national physical protection regime effectively and the spread of the nuclear security culture. The 2010 Nuclear Security Summit was held in Washington, DC to enhance international cooperation to prevent nuclear terrorism. During the Summit, the South Korea was chosen to host the second Nuclear Summit in 2012. South Korean President announced that South Korea would share its expertise and support the Summit's mission by setting up an international education and training center on nuclear security in 2014. KINAC is making a full effort to set up the center successfully. An important function of the center is education and training in the subjects of nuclear nonproliferation, nuclear safeguards, nuclear security, and nuclear export/import control. With increasing importance of education and training education on nuclear nonproliferation and control, KINAC has been developing computer-aided learning programs on nuclear nonproliferation and control to overcome the weaknesses in classroom educations. This paper shows two learning programs. One is an e-learning system on the nuclear nonproliferation and control and the other is a virtual reality program for training nuclear material accountancy inspection of light water

INA's Preparations for Liberalised Energy Market and Privatisation

International Nuclear Information System (INIS)

Dragicevic, T.; Kolundzic, S.

2001-01-01

Before opening of the market, energy entities must carry out numerous preparations in order to be ready for challenges of a competitive environment. Some preparations refer to legal and organisational issues, but many of them encompass reengineering of business processes, cost reduction schemes and various improvement measures aimed at maintenance or acquisition of a competitive advantage. INA is actively pursuing some of the above measures, but now, by the end of 2001, we also have to deal with preparations for privatisation. These two processes have some important common elements, competitiveness being certainly one of them. INA must work toward improving its competitive strength in the gas sector, in refining, in marketing of oil products, but also in various supporting activities. However, there are constraints that we have to observe, mainly related to social issues.(author)

Non-proliferation and disarmament

International Nuclear Information System (INIS)

Ritter von Wagner, A.

1993-01-01

In 1995 the Conference on the prolongation of the Non-Proliferation Treaty will take place. Will it be extended for a long term, indefinitely or only for a fixed period? The Federal Government of Germany advocates an unlimited extension of the Non-Proliferation Treaty. Others have different ideas alleging that the Treaty is imperfect and discriminating. It is a thorn in the side of many States, in particular of the Third World, which no longer want to put up with being treated as second-class states. One argument which is considered especially embarrassing by developing countries as a visible expression of such discrimination, are the nuclear tests which are still carried out by nuclear weapon states. Is the political situation still such that one needs those weapons? Strategists gradually find it difficult to argument; over and over again they claim that an abandonment of nuclear weapons would make the world unsafer. But development has gradually passed over them. Nevertheless, one finds it hard to throw overboard considerations which for years have determined one's thinking. (orig./HSCH) [de

Atomic Energy Amendment Act 1978, No. 31

International Nuclear Information System (INIS)

1978-01-01

This Act amends certain Sections of the Atomic Energy Act 1953. The principal modifications concern the definitions of atomic energy, prescribed substances, the provision and supply of uranium in relation to the functions of the Atomic Energy Commission, compliance with the agreement with the IAEA on the application of safeguards under the Non-Proliferation Treaty as well as with any agreement with any other international organization or another country. The Act also amends the 1953 Act in respect of the control of prescribed substances and repeals the section concerning jurisdiction of courts. (NEA) [fr

The new US nuclear non-proliferation and export policy

International Nuclear Information System (INIS)

Welck, S. von.

1981-01-01

The future American nuclear non-proliferation and export policy will be determined chiefly by three elements: (1) Adherence to the former objective of nuclear non-proliferation. (2) A large and varied assortment of old and new tools for implementing this goal. (3) Much more differentiation in applying these tools in the light of the reliability, with respect to non-proliferation policy, of the respective partner. Consequently, it would make little sense for the new Administration to force upon allied industrialized countries, whose nuclear technologies are at the same level as that of the United States, restrictive rules on reprocessing and breeder technology. The new measures designed to curb proliferation are especially meant to destroy motivations that could cause states to own nuclear explosives. This also applies to the removal of economic motivations. (orig.) [de

Multilateral Cooperation on Nonproliferation

Science.gov (United States)

2012-10-01

Nathan E . Busch and Daniel H. Joyner, eds., Combating Weapons of Mass Destruction: The Future of International Nonproliferation Policy (Athens, GA...or the World Bank . These organizations receive contributions from member states but have their own...Opening Reception Jack’s Lounge , Portola Hotel Friday, March 30, 2010 Timeline Content Delivery 7:30-8:30 Breakfast and Registration Cottonwood

Experience in non-proliferation verification: The Treaty of Raratonga

International Nuclear Information System (INIS)

Walker, R.A.

1998-01-01

The verification provisions of the Treaty of Raratonga are subdivided into two categories: those performed by IAEA and those performed by other entities. A final provision of the Treaty of Raratonga is relevant to IAEA safeguards according to support of the continued effectiveness of the international non-proliferation system based on the Non-proliferation Treaty and the IAEA safeguards system. The non-IAEA verification process is described as well

InAs film grown on Si(111) by metal organic vapor phase epitaxy

International Nuclear Information System (INIS)

Caroff, P; Jeppsson, M; Mandl, B; Wernersson, L-E; Wheeler, D; Seabaugh, A; Keplinger, M; Stangl, J; Bauer, G

2008-01-01

We report the successful growth of high quality InAs films directly on Si(111) by Metal Organic Vapor Phase Epitaxy. A nearly mirror-like and uniform InAs film is obtained at 580 0 C for a thickness of 2 μm. We measured a high value of the electron mobility of 5100 cm 2 /Vs at room temperature. The growth is performed using a standard two-step procedure. The influence of the nucleation layer, group V flow rate, and layer thickness on the electrical and morphological properties of the InAs film have been investigated. We present results of our studies by Atomic Force Microscopy, Scanning Electron Microscopy, electrical Hall/van der Pauw and structural X-Ray Diffraction characterization

Channeling study of laser-induced defect generation in InP and InAs

International Nuclear Information System (INIS)

Burdel', K.K.; Kashkarov, P.K.; Timoshenko, V.Yu.; Chechenin, N.G.

1992-01-01

Damage production in InP and InAs single crystals induced by a ruby-laser pulse irradiation with τ p =20 ms in the energy density region W=0.05-1.0 J/cm 2 is studied by the channeling and Rutherford backscattering techniques. The defect generation threshold was determined to be equal to 0.2 J/cm 2 and 0.55 J/cm 2 for InP and InAs crystals, respectively. Stoichiometric defects in InP crystals were observed at W>=0.5 J/cm 2 . The temperature fields in InP and InAs under laser irradiation were calculated. The experimental observations are considered as a result of a selective evaporation of the components from the melt

Evaluation of the Administration's proposed nuclear non-proliferation strategy. Report to the Congress

International Nuclear Information System (INIS)

1977-01-01

Dwindling supplies of fossil fuels are causing countries to turn increasingly to nuclear power as a major source of energy. Although nuclear power holds out the promise of energy independence, it has a formidable drawback--it can also lead to the proliferation of nuclear weapons. In April, the President announced a new policy designed to curb nuclear proliferation and the executive branch proposed legislation entitled 'The Nuclear Non-Proliferation Policy Act of 1977.' The strategy outlined in these documents calls for stricter export controls and safeguards as well as actions affecting uranium enrichment services, reprocessing, storing of spent fuel, and disposing of radioactive nuclear wastes. GAO analyzed this non-proliferation strategy as it relates to: Improving nuclear export controls; Strengthening international nuclear safeguards; Maintaining U.S. reliability as a supplier of uranium enrichment services; Deferring U.S. reprocessing of spent fuel as an example for others; Reducing risk of proliferation by controlling spent reactor fuel. In general, GAO concluded that the administration's strategy is constructive but noted some weaknesses which should be addressed. Some of the problems noted in this report may already have been addressed by congressional committees in their markup of the legislation

Institutional overviews. Overview of the JAEA and the Nuclear Nonproliferation Science and Technology Center

International Nuclear Information System (INIS)

Senzaki, Masao

2006-01-01

The Nuclear Nonproliferation Science and Technology Center (NPSTC) was formed within the new Japan Atomic Energy Agency (JAEA) to carry out safeguards and material control duties for the JAEA. Development of technologies and procedures for safeguards is an important duty. In addition, the new NPSTC will assume a 'think tank' role in support of the nonproliferation regime, help train nonproliferation experts, and cooperate with academic, government and non-governmental organizations on nonproliferation issues. This report briefly summarizes the formation of the JAEA and describes the duties and structure of the NPSTC in detail. (author)

Chemical and biological nonproliferation program. FY99 annual report

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

This document is the first of what will become an annual report documenting the progress made by the Chemical and Biological Nonproliferation Program (CBNP). It is intended to be a summary of the program's activities that will be of interest to both policy and technical audiences. This report and the annual CBNP Summer Review Meeting are important vehicles for communication with the broader chemical and biological defense and nonproliferation communities. The Chemical and Biological Nonproliferation Program Strategic Plan is also available and provides additional detail on the program's context and goals. The body of the report consists of an overview of the program's philosophy, goals and recent progress in the major program areas. In addition, an appendix is provided with more detailed project summaries that will be of interest to the technical community.

Perspectives and benefits of the non-proliferating fuel cycle

International Nuclear Information System (INIS)

Parker, F.

2012-01-01

The world community has faced the issues of nuclear non-proliferation for decades. Frank Parker, Emeritus Distinguished Professor at Vanderbilt University, has proposed a non-proliferating fuel cycle, which greatly reduces the risk of use of nuclear materials for military purpose. A simplified fuel cycle with reduced opportunities for proliferation of nuclear weapons and permanent disposal of radioactive wastes as well as a reference sub-seabed HLW disposal system are described [ru

Argentina’s nuclear development and the non-proliferation regime

OpenAIRE

Sandra Colombo; Cristian Guglielminotti; María Nevia Vera

2017-01-01

The development and transfer of nuclear technology have been put under strict control due to its possible military use, leading to the creation of international non-proliferation regimes. One of the latest proposals was the creation of multilateral banks of low enriched uranium (leu). The article states that, under the goal of non-proliferation, this initiative can contribute to accentuate the asymmetry in the distribution of world economic and political power, damaging the endogenous develop...

The IAEA and non-proliferation: is quiescence progress

International Nuclear Information System (INIS)

Herron, L.W.

1983-01-01

The purpose of this paper is to evaluate the current status of more important non-proliferation aspects affecting or involving the IAEA. The questions dealt with cover in particular the Non-Proliferation Treaty, the Tlatelolco Treaty, the Committee on Assurances of Supply established by the IAEA in 1980 and the International Plutonium Storage Study prepared by an IAEA expert group. The author concludes that in a number of areas involving this Agency, recent considerable activity at both political and technical levels has produced few tangible results althrough the situation is not static. (NEA) [fr

The nuclear non-proliferation regime: What it is and how it has evolved

International Nuclear Information System (INIS)

Priest, J.

1999-01-01

The nuclear non-proliferation regime commonly denotes the legal norms, voluntary undertakings and policies which the international community has developed to deal with the threat of nuclear weapons proliferation. The word 'regime' suggests a legally binding order. Some components of the non-proliferation regime are indeed legally binding. Others represent essentially political rather than legal commitments. This lecture describes the various independent but mutually reinforcing components of the non-proliferation regime. It thus touches on and highlights the particular importance of political incentives - or disincentives - to the acquisition of nuclear weapons; legal undertakings in which non-proliferation commitments are anchored; verification (specifically the IAEA Safeguards System); compliance and enforcement; export controls; physical protection measures; regional nuclear non-proliferation initiatives; and measures taken to curb proliferation in general and to strive for arms control and nuclear disarmament. The purpose of the lecture is to provide an over-arching, tour d'horizon for the more specific and detailed lectures which follow. (author)

InAs nanocrystals on SiO2/Si by molecular beam epitaxy for memory applications

International Nuclear Information System (INIS)

Hocevar, Moiera; Regreny, Philippe; Descamps, Armel; Albertini, David; Saint-Girons, Guillaume; Souifi, Abdelkader; Gendry, Michel; Patriarche, Gilles

2007-01-01

We studied a memory structure based on InAs nanocrystals grown by molecular beam epitaxy directly on thermal SiO 2 on silicon. Both nanocrystal diameter and density can be controlled by growth parameters. Transmission electron microscopy analysis shows high crystallinity and low size dispersion. In an electrical test structure with a 3.5 nm tunnel oxide, we observed that 80% of the initial injected electrons remain stored in the InAs nanocrystals after 3 months and that the retention time for electrons in InAs nanocrystals is four orders of magnitude higher than in silicon nanocrystals

Historical survey of nonproliferation policies

International Nuclear Information System (INIS)

Goldschmidt, B.

1977-01-01

This paper briefly surveys the successive nonproliferation policies and their influence on international commerce and the reaction of the countries where they were applied: the war policy, secrecy policy, liberal policy, safeguarded assistance policy, nonproliferation treaty policy, suppliers' policy, French policy, and the no weapon-usable material policy. It is emphasized that any new solution of the problem must not appear to delay or limit in any way a nation's access to nuclear energy, nor to make any countries dependent on others to meet their energy requirements. Therefore, in the choice of a future policy, political considerations are more important than technical or legal ones. The greatest catalyst of proliferation is the spread of national autarchic programs, and these can only be avoided within a general climate of international trust. The escalation of mistrust between the countries possessing the technological information and those desiring it must be dispelled. Such a policy will have to be clear and stable

IAEA Director General calls for rededication to nuclear non-proliferation regime

International Nuclear Information System (INIS)

2000-01-01

Speaking at the opening session of the Review Conference of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) in New York on April 24, 2000, the Director General of the IAEA urged all nations to commit themselves unequivocally to the basic tenets of the non-proliferation regime

US Nuclear Non-Proliferation Policy: impact on exports and nuclear industry could not be determined

International Nuclear Information System (INIS)

Staats, E.B.

1980-01-01

The Nuclear Non-Proliferation Act of 1978 established new measures to prevent the diversion to weapons use of peaceful nuclear exports. It also created a policy to confirm US reliability as a nuclear supplier. GAO did not identify any export sales lost as a result of the Act, but did find indications that nonprofileration policies can influence export sales. Based on avavailable data, GAO could not determine the impact of the Act on the competitiveness of US nuclear exports. However, US companies are at some disadvantage because importers perceive that implementation of the Act may result in delayed export licenses. The United States dominated the nuclear export market through the early 1970s. However, foreign competitors, some aided by US technology transfers, emerged to monopolize home markets and complete for third-country business. Further, the market has been depressed since 1974 and prospects for US nuclear power plant exports have dimmed greatly. However, US companies continue to view exports as important to sustain production capacity

Cooperative transparency for nonproliferation. Technology demonstrations at the Joyo test bed for advanced remote monitoring

International Nuclear Information System (INIS)

Betsill, J. David; Hashimoto, Yu

2009-01-01

The term 'Transparency' has been used widely by many authors and practitioners for various purposes, and there is an assortment of definitions for the term. These definitions vary depending on the field in which the term is used and within the context of its usage. For the purposes of our current project on regional, cooperative nonproliferation transparency and remote monitoring, the relevant field is nuclear nonproliferation, and in this context, we define the term Cooperative Nonproliferation Transparency as: 'Providing sufficient and appropriate information to a cooperating party so that they can independently develop their own evaluation and assessment of the reviewed party regarding their consistency with nonproliferation goals.' Key aspects of cooperative nonproliferation transparency activities include mutually agreeing upon the type of information or data that will be shared, how it will be collected, and who has access to that information. The Japan Atomic Energy Agency's (JAEA) Nonproliferation Science and Technology Center (NPSTC) has been exploring the possible use, development, and application of methods and technologies for Cooperative Transparency for Nonproliferation to support regional confidence building and cooperation n the peaceful use of nuclear energy throughout the East Asia region. (author)

Non-proliferation and nuclear disarmament

International Nuclear Information System (INIS)

Shea, M.

2000-01-01

Fissionable materials are common to all nuclear weapons and controls on the production, storage, processing and use of fissionable materials provides one means to address non-proliferation and disarmament. In this article, the relevance of such controls is examined and the current situation and future prospects are assessed. (authors)

URENCO: A Multinational Contribution to Non-Proliferation

International Nuclear Information System (INIS)

Korbmacher, T.

2015-01-01

URENCO was founded in 1970 following the signing of the Treaty of Almelo by the governments of Germany, the Netherlands and the UK. The fundamental principles for effective supervision of URENCO's technology and enrichment operations with respect to non-proliferation issues have been laid down in this treaty. In order to enable the construction of a URENCO enrichment facility in the USA and to permit the transfer of classified information into the USA, another treaty has been concluded in 1992. The US government entered into the Treaty of Washington together with the governments of Germany, the Netherlands and the UK to ensure that the same conditions that had been agreed in the Treaty of Almelo would also apply to the US. To allow for the completion of the joint venture with Areva regarding the URENCO Group's technology business ETC, the Treaty of Cardiff has been signed on 12 July 2005 by the governments of Germany, the Netherlands, the UK and France. Through this treaty, France is obliged to adhere to the principles of the Treaty of Almelo. For each treaty, control bodies have been formed with representatives of the governments of the signatory countries. These committees exercise the role of effective supervision of the technology and operations with respect to non-proliferation issues. They also consider all questions concerning the safeguards system (as established by IAEA/Euratom), classification arrangements and security procedures, exports of the technology and enriched uranium, as well as other non-proliferation issues. The presentation describes how the multinational structure of URENCO contributes to Non-Proliferation on the basis of the above mentioned treaties. Beyond that, the international cross linking of operational working groups and committees within the URENCO Group structure is explained. This structure implies an additional assurance to achieve the safeguards goals set. (author)

Reactive ion etching of GaSb, (Al,Ga)Sb, and InAs for novel device applications

International Nuclear Information System (INIS)

LaTulipe, D.C.; Frank, D.J.; Munekata, H.

1991-01-01

Although a variety of novel device proposals for GaSb/(Al,Ga)Sb/InAs heterostructures have been made, relatively little is known about processing these materials. The authors of this paper have studied the reactive ion etching characteristics of GaSb, (Al,Ga)Sb, and InAs in both methane/hydrogen and chlorine gas chemistries. At conditions similar to those reported elsewhere for RIE of InP and GaAs in CH 4 /H 2 , the etch rate of (Al,Ga)Sb was found to be near zero, while GaSb and InAs etched at 200 Angstrom/minute. Under conditions where the etch mechanism is primarily physical sputtering, the three compounds etch at similar rates. Etching in Cl 2 was found to yield anistropic profiles, with the etch rate of (Al,Ga)Sb increasing with Al mole fraction, while InAs remains unetched. Damage to the InAs stop layer was investigated by sheet resistance and mobility measurements. These etching techniques were used to fabricate a novel InAs- channel FET composed of these materials. Several scanning electron micrographs of etching results are shown along with preliminary electrical characteristics

Non-proliferation and international safeguards. [Booklet by IAEA

Energy Technology Data Exchange (ETDEWEB)

1978-01-01

This booklet consists of 13 separate, brief analyses related to the subject title, namely: The International Scope of IAEA Safeguards; Application of Safeguards Procedures; Computer-Based Safeguards Information and Accounting System; IAEA Training Activities Related to State Systems of Nuclear Materials Accountancy and Control; Surveillance and Containment Measures to Support IAEA Safeguards; International Plutonium Management; Safeguards for Reprocessing and Enrichment Plants; Non-Destructive Assay: Instruments and Techniques for Agency Safeguards; The Safeguards Analytical Laboratory: Its Functions and Analytical Facilities; Resolution of the UN General Assembly on the Treaty on the Non-Proliferation of Nuclear Weapons of 12 June 1968; The Treaty on the Non-Proliferation of Nuclear Weapons; Final Declaration of the Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons, May 1975; Resolutions on the IAEA's Work in the Field of the Peaceful Uses of Atomic Energy, adopted by the UN General Assembly on 8 and 12 December, 1977; and a Map on the NPT situation in the world (with explanations).

New dimensions in nonproliferation -- An International Atomic Energy Agency view

International Nuclear Information System (INIS)

Pelland, B.

1994-01-01

Four years ago, Saddam Hussein invaded Kuwait with the intention of annexing it as Iraq's 19th state. The disclosure of the Iraqi nuclear weapons program in the aftermath of the Gulf War--through the IAEA inspections--signaled the end of one proliferation era and the start of the next. In the author's remarks here, he has found it useful to identify four distinct proliferation eras, each with different features, each calling for different emphasis in international nonproliferation efforts. They provide a convenient way to look at the history of nonproliferation, and to look into the future and to the new dimensions in nonproliferation that are slowly emerging. Since the Gulf War, the nuclear world experienced a series of events of fundamental significance that changed the nature of nonproliferation, forcing changes in the mission of the IAEA and its methods. Certainly some of these events came in the form of unpleasant surprises, such as in Iraq, but very positive progress was also made on other fronts. He would like to share some perceptions of the events creating the present situation, and some views anticipating the requirements most likely to emerge in the coming years

The Nuclear Non-Proliferation Treaty: Regulating Nuclear Weapons around the World

Science.gov (United States)

Middleton, Tiffany Willey

2010-01-01

In May 2010, scientists, national security experts, and state delegates from nations around the world will convene in New York for the 2010 Nuclear Non-Proliferation Treaty Review Conference. They will review current guidelines for nuclear testing and possession of nuclear weapons in accordance with the Nuclear Non-Proliferation Treaty of 1968,…

Past and Present Development of INA's Liberalisation and Privatisation

International Nuclear Information System (INIS)

Lesic, A.; Stimac, B.

2001-01-01

The paper deals with the historical development aspects of the Croatian oil and gas industry INA. It describes the period from the very start of oil and gas production to the data of establishment of the Croatian state and afterwards. Some important milestones and political and economic events that impacted the development of the Croatian oil industry are described and commented, including changes toward liberalisation and privatisation of the oil and gas sector. The paper emphasises the role of INA in the Croatian economy and proposes some solutions for the liberalisation process and privatisation of the company that could prevent undesirable effects of privatisation and protect the interests of Croatia in the energy sector which is one of the main sectors of economy having influence on other production and service sectors and their competitiveness.(author)

Conductive atomic force microscopy study of InAs growth kinetics on vicinal GaAs (110)

International Nuclear Information System (INIS)

Tejedor, Paloma; Diez-Merino, Laura; Beinik, Igor; Teichert, Christian

2009-01-01

Conductive atomic force microscopy has been used to investigate the effect of atomic hydrogen and step orientation on the growth behavior of InAs on GaAs (110) misoriented substrates. Samples grown by conventional molecular beam epitaxy exhibit higher conductivity on [110]-multiatomic step edges, where preferential nucleation of InAs nanowires takes place by step decoration. On H-terminated substrates with triangular terraces bounded by [115]-type steps, three-dimensional InAs clusters grow selectively at the terrace apices as a result of a kinetically driven enhancement in upward mass transport via AsH x intermediate species and a reduction in the surface free energy.

Examination of Relationship between Nuclear Transparency and Nonproliferation

Energy Technology Data Exchange (ETDEWEB)

Ha, Jee-Min; Yim, Man-Sung; Park, Hyeon Seok; Kim, So Young [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

2015-05-15

In this study, we define the state-level nuclear transparency as a set of the condition that shows how clearly the state's information related to peaceful nuclear power program and nuclear proliferation is revealed to the international community. For conducting expert survey on state-level nuclear transparency, the concept of nuclear transparency should be clearly defined. Based on that concept, the survey was carried out and results show that it tend to score high when nonproliferation activities happen. It means that higher transparency is positively related to nuclear proliferation. Therefore, higher nuclear transparency is positively related to nuclear nonproliferation.

Examination of Relationship between Nuclear Transparency and Nonproliferation

International Nuclear Information System (INIS)

Ha, Jee-Min; Yim, Man-Sung; Park, Hyeon Seok; Kim, So Young

2015-01-01

In this study, we define the state-level nuclear transparency as a set of the condition that shows how clearly the state's information related to peaceful nuclear power program and nuclear proliferation is revealed to the international community. For conducting expert survey on state-level nuclear transparency, the concept of nuclear transparency should be clearly defined. Based on that concept, the survey was carried out and results show that it tend to score high when nonproliferation activities happen. It means that higher transparency is positively related to nuclear proliferation. Therefore, higher nuclear transparency is positively related to nuclear nonproliferation

Chemical and biological nonproliferation program. FY99 annual report; ANNUAL

International Nuclear Information System (INIS)

NONE

2000-01-01

This document is the first of what will become an annual report documenting the progress made by the Chemical and Biological Nonproliferation Program (CBNP). It is intended to be a summary of the program's activities that will be of interest to both policy and technical audiences. This report and the annual CBNP Summer Review Meeting are important vehicles for communication with the broader chemical and biological defense and nonproliferation communities. The Chemical and Biological Nonproliferation Program Strategic Plan is also available and provides additional detail on the program's context and goals. The body of the report consists of an overview of the program's philosophy, goals and recent progress in the major program areas. In addition, an appendix is provided with more detailed project summaries that will be of interest to the technical community

Issues of weapons of mass destruction non-proliferation in Tajikistan

International Nuclear Information System (INIS)

Mirsaidov, U.M.

2010-01-01

This article is devoted to issues of weapons of mass destruction non-proliferation in Tajikistan. Over a period of 20 century, starting from First World War, the weapons of mass destruction arouse serious concern of world community. Geneva protocol of 1925 prohibits the use of chemical and biological weapons. Once nuclear weapon was created, the weapons of mass destruction distributions become the subject of high concern. Besides, during the end of 'cold war', regional conflicts, collapse of Soviet Union, as well as access to sensitive technologies considerably increase the danger of weapons of mass destruction distribution. More than 10 countries have active programs, relating to weapons of mass destruction and, possibly, more than ten countries have potential to start implementing such kinds of programs. Nowadays, trans national organized criminal groups and international terrorist networks are appeared in the world scene, which show interest in obtaining an access to sensitive materials, technologies, weapons and their distribution. After 11 September events, the risk of such weapons of mass destruction components use by such forces for Governments blackmail become real scene, which, despite of low possibility of this threat implementation, could have very serious and disastrous consequences. International community responded to these problems and challenges, basically through the following actions, which is detailed regime development of multilateral international treaties, directed to weapons of mass destruction distribution prevention. Non-proliferation treaty of nuclear weapons, Convention on prohibition of chemical weapons and Convention on prohibition of biological and toxin weapons are some of them. As it is known, Tajikistan signed all these treaties. For different reasons these treaties were subject of serious tests. Nuclear weapons tests in India and Pakistan in 1998 year, actual Israel status as state having nuclear weapon and North Korean program on

The emerging nuclear suppliers and nonproliferation

International Nuclear Information System (INIS)

Potter, W.C.

1990-01-01

The number of states capable of exporting nuclear material, technology, equipment, and services is large and growing. Once confined primarily to states party to the Nuclear Non-Proliferation Treaty (NPT), the list of actual and potential nuclear suppliers now includes many countries that do not subscribe to the NPT or to other international nuclear export control agreements. Although international control accords---such as the Nuclear Exporters' (Zangger) Committee and the London Nuclear Suppliers Group (NSG) guidelines---do not prohibit the export of sensitive nuclear materials and equipment, they do reduce the risks of proliferation by imposing international safeguards as a condition for export. The purpose of this book---the culmination of one phase of an ongoing international research project on the emerging nuclear suppliers and nonproliferation---is to remedy, at least in part, this data deficiency

Canada and international safeguards. Verifying nuclear non-proliferation. Verification brochure no. 5

Energy Technology Data Exchange (ETDEWEB)

1990-01-01

The Non-Proliferation Treaty (NPT) came into force in 1970 and now has about 140 signatory nations. By creating legal barriers against proliferation and by promoting an international non-proliferation ethic, the NPT has promoted international peace and security. A key ingredient has been the confidence generated through verification by IAEA safeguards. By the end of 1988 IAEA safeguards agreements had been concluded with about 100 countries, including Canada. Over 500 nuclear facilities worldwide are under safeguards or contain safeguarded nuclear material. The existence of this credible and effective safeguards system makes international trade in nuclear equipment and materials possible, monitoring the transfer of nuclear technology to developing countries as well as between industrial countries. Canada is committed to non-proliferation and IAEA safeguards. Canadian non-proliferation policy is among the strictest in the world, even though opportunities have been lost to sell Canadian technology abroad as a result.

Nuclear non-proliferation and disarmament: A long-term perspective

International Nuclear Information System (INIS)

Haeckel, E.

1990-01-01

International nuclear policy has been determined for a long time by the exigencies of the status quo. The non-proliferation regime draws its legitimacy from the continuation of extant patterns of power in world politics. Such a static policy cannot succeed forever. Overcoming the threat of nuclear proliferation will require innovative strategy that reaches beyond the status quo. It calls for structural change in the international system to be accomodated instead of resisted. If the Non-Proliferation Treaty is to hold, nuclear weapon states will finally have to forgo their privileged status. This cannot, however, be accomplished simply through the abolition or renunciation of nuclear weapons since nuclear weapons themselves continue to be instrumental for war prevention and international stability. Rather, what is needed is a new approach to the management of the nuclear world system under international responsibility. Nonproliferation and disarmament objectives together call for a concept of global security in which multilateral institutions assume an increasingly important role of nuclear diplomacy. (orig.) [de

University-level Non-proliferation and Safeguards Education and Human Capital Development Activities at Brookhaven National Laboratory

Energy Technology Data Exchange (ETDEWEB)

Bachner K. M.; Pepper, S.; Gomera, J.; Einwechter, M.; Toler, L. T.

2016-07-24

BNL has offered Nuclear Nonproliferation, Safeguards and Security in the 21st Century,? referred to as NNSS, every year since 2009 for graduate students in technical and policy fields related to nuclear safeguards and nonproliferation. The course focuses on relevant policy issues, in addition to technical components, and is part of a larger NGSI short course initiative that includes separate courses that are delivered at three other national laboratories and NNSA headquarters. [SCHOLZ and ROSENTHAL] The course includes lectures from esteemed nonproliferation experts, tours of various BNL facilities and laboratories, and in-field and table-top exercises on both technical and policy subjects. Topics include the history of the Treaty on the Non-proliferation of Nuclear Weapons (NPT) and other relevant treaties, the history of and advances in international nuclear safeguards, current relevant political situations in countries such as Iran, Iraq, and the Democratic Peoples? Republic of Korea (DPRK), nuclear science and technology, instrumentation and techniques used for verification activities, and associated research and development. The students conduct a mock Design Information Verification (DIV) at BNL?s decommissioned Medical Research Reactor. The capstone of the course includes a series of student presentations in which students act as policy advisors and provide recommendations in response to scenarios involving a current nonproliferation related event that are prepared by the course organizers. ?The course is open to domestic and foreign students, and caters to students in, entering, or recently having completed graduate school. Interested students must complete an application and provide a resume and a statement describing their interest in the course. Eighteen to 22 students attend annually; 165 students have completed the course to date. A stipend helps to defray students? travel and subsistence expenses. In 2015, the course was shortened from three weeks to

GaAs structures with InAs and As quantum dots produced in a single molecular beam epitaxy process

International Nuclear Information System (INIS)

Nevedomskii, V. N.; Bert, N. A.; Chaldyshev, V. V.; Preobrazhenskii, V. V.; Putyato, M. A.; Semyagin, B. R.

2009-01-01

Epitaxial GaAs layers containing InAs semiconductor quantum dots and As metal quantum dots are grown by molecular beam epitaxy. The InAs quantum dots are formed by the Stranskii-Krastanow mechanism, whereas the As quantum dots are self-assembled in the GaAs layer grown at low temperature with a large As excess. The microstructure of the samples is studied by transmission electron microscopy. It is established that the As metal quantum dots formed in the immediate vicinity of the InAs semiconductor quantum dots are larger in size than the As quantum dots formed far from the InAs quantum dots. This is apparently due to the effect of strain fields of the InAs quantum dots upon the self-assembling of As quantum dots. Another phenomenon apparently associated with local strains around the InAs quantum dots is the formation of V-like defects (stacking faults) during the overgrowth of the InAs quantum dots with the GaAs layer by low-temperature molecular beam epitaxy. Such defects have a profound effect on the self-assembling of As quantum dots. Specifically, on high-temperature annealing needed for the formation of large-sized As quantum dots by Ostwald ripening, the V-like defects bring about the dissolution of the As quantum dots in the vicinity of the defects. In this case, excess arsenic most probably diffuses towards the open surface of the sample via the channels of accelerated diffusion in the planes of stacking faults.

On the evolution of InAs thin films grown by molecular beam epitaxy on the GaAs(001) surface

International Nuclear Information System (INIS)

Grabowski, Jan

2010-01-01

Semiconductor nanostructures are currently of high interest for a wide variety of electronic and optoelectronic applications. A large number of devices, in particular for the optical data transmission in the long-wavelength range, essential in modern communication, are based on InAs/GaAs quantum dot (QD) structures. Though the properties of the InAs/GaAs QDs have been extensively studied, only little is known about the formation and structure of the wetting layer (WL) yet. In the present work, the pathway of the InAs WL evolution is studied in detail. For this purpose, InAs thin films in the range of one monolayer (ML) are deposited on the GaAs(001) surface by molecular beam epitaxy (MBE) and studied by reflection high energy electron diffraction (RHEED) and in particular by scanning tunneling microscopy (STM). The InAs thin films are grown in both typical growth regimes, on the GaAs-c(4 x 4) and the GaAs-β2(2 x 4) reconstructed surface, in a variety of thicknesses starting from submonolayers with 0.09 ML of InAs up to 1.65 ML of InAs exceeding the critical thickness for QD growth. In principle, three growth stages are found. At low InAs coverages, the indium adsorbs in agglomerations of typically eight In atoms at energetically preferable surface sites. In the STM images, the signatures of these In agglomerations appear with a clear bright contrast. A structural model for the initial formation of these signatures is presented, and its electronic and strain related properties are discussed. At an InAs coverage of about 0.67ML the initial surface transforms into a (4 x 3) reconstructed In 2/3 Ga 1/3 As ML and the detailed structure and strain properties of this surface are unraveled. On top of the InGaAs ML further deposited InAs forms a second layer, characterized by a typical zig-zag alignment of (2 x 4) reconstructed unit cells, with an alternating α2/α2-m configuration. In contrast to the previous surface reconstructions, where structural strain is

On the evolution of InAs thin films grown by molecular beam epitaxy on the GaAs(001) surface

Energy Technology Data Exchange (ETDEWEB)

Grabowski, Jan

2010-12-14

Semiconductor nanostructures are currently of high interest for a wide variety of electronic and optoelectronic applications. A large number of devices, in particular for the optical data transmission in the long-wavelength range, essential in modern communication, are based on InAs/GaAs quantum dot (QD) structures. Though the properties of the InAs/GaAs QDs have been extensively studied, only little is known about the formation and structure of the wetting layer (WL) yet. In the present work, the pathway of the InAs WL evolution is studied in detail. For this purpose, InAs thin films in the range of one monolayer (ML) are deposited on the GaAs(001) surface by molecular beam epitaxy (MBE) and studied by reflection high energy electron diffraction (RHEED) and in particular by scanning tunneling microscopy (STM). The InAs thin films are grown in both typical growth regimes, on the GaAs-c(4 x 4) and the GaAs-{beta}2(2 x 4) reconstructed surface, in a variety of thicknesses starting from submonolayers with 0.09 ML of InAs up to 1.65 ML of InAs exceeding the critical thickness for QD growth. In principle, three growth stages are found. At low InAs coverages, the indium adsorbs in agglomerations of typically eight In atoms at energetically preferable surface sites. In the STM images, the signatures of these In agglomerations appear with a clear bright contrast. A structural model for the initial formation of these signatures is presented, and its electronic and strain related properties are discussed. At an InAs coverage of about 0.67ML the initial surface transforms into a (4 x 3) reconstructed In{sub 2/3}Ga{sub 1/3}As ML and the detailed structure and strain properties of this surface are unraveled. On top of the InGaAs ML further deposited InAs forms a second layer, characterized by a typical zig-zag alignment of (2 x 4) reconstructed unit cells, with an alternating {alpha}2/{alpha}2-m configuration. In contrast to the previous surface reconstructions, where

Alloy formation during InAs nanowire growth on GaAs(111)

Energy Technology Data Exchange (ETDEWEB)

Davydok, Anton; Saqib, Muhammad; Biermanns, Andreas; Pietsch, Ullrich [Festkoerperphysik, Universitaet Siegen (Germany); Rieger, Torsten; Grap, Thomas; Lepsa, Mihail [Peter Gruenberg Institut 9, Forschungszentrum Juelich (Germany); JARA - Fundamentals of Future Information Technology (Germany)

2012-07-01

The growth of semiconductor nanowires has attracted significant interest in recent years due to the possible fabrication of novel semiconductor devices for future electronic and opto-electronic applications. A possible way to obtain nanowires is the growth in molecular beam epitaxy on the (111)B oriented surface of the desired substrate, covered by a thin oxide layer. A crucial parameter in this method is the initial thickness of the oxide layer, often determined by an etching procedure. In this contribution, we report on the structural investigation of InAs nanowires grown on GaAs substrates covered by different oxide-layers using X-ray diffraction. In this contribution, we report on the structural investigation of InAs nanowires grown via an In droplet on GaAs substrates covered by different oxide layers using X-ray diffraction. Using a combination of symmetric and asymmetric X-ray diffraction, we observe that for growth on a defective oxide layer, alloy formation takes place and a large amount of InGaAs is formed, whereas for growth on an initially smooth oxide layer, only pure InAs is formed.

Isolation, Fractionation and Characterization of Catalase from Neurospora crassa (InaCC F226)

Science.gov (United States)

Suryani; Ambarsari, L.; Lindawati, E.

2017-03-01

Catalase from Indigenous isolate Neurospora crassa InaCC F226 has been isolated, fractionated and characterized. Production of catalase by Neurospora crassa was done by using PDA medium (Potato Dextrosa Agar) and fractionated with ammonium sulphate with 20-80% saturation. Fraction 60% was optimum saturation of ammonium sulphate and had highest specific activity 3339.82 U/mg with purity 6.09 times, total protein 0.920 mg and yield 88.57%. The optimum pH and temperature for catalase activity were at 40°C and pH 7.0, respectively. The metal ions that stimulated catalase activity acted were Ca2+, Mn2+ and Zn2+, and inhibitors were EDTA, Mg2+ and Cu2+. Based on Km and Vmax values were 0.2384 mM and 13.3156 s/mM.

Promotion of Nuclear Non-proliferation in East Asia

International Nuclear Information System (INIS)

Hwang, Yong Soo

2009-07-01

KAERI has jointly worked with Sandia National Laboratories for Nuclear Energy Non-proliferation in East Asia for the last five years. This project aims at support activities in this joint project between two states. The annual meetings were held during the project period, the 4th one in 2008 and the 5th one in 2009. In addition code comparison between KAERI and SNL's codes for assessing the back-end fuel cycle options was carried out. This project strongly enhances the close tie for the non-proliferation, transparency and safeguards among Korea Japan China Taiwan the United States Russia Malaysia Singapore Indonesia Thailand Vietnam and others for the project period

The Rarotonga treaty: regional approach to non-proliferation in the South Pacific

International Nuclear Information System (INIS)

Papadimitropulos, P.

1988-01-01

The regional approach to the problem of non-proliferation in the South-Pacific-the Rarotonga treaty - is discussed. The regional approach to the problem of non-proliferation is aimed in a wide sense at the assistance to detante in a certain region and the propagation of measures strengthening confidence there. On December 11, 1975 at the initiative of New Zealand and Fiji the UN General Assembly adopted a resolution on the nuclear-free zone in the South-Pacific. In compliance with the Rarotonga treaty a large nuclear-free zone is created. The participants of the Rarotonga Treaty assess the values of the Non-Proliferation Treaty

Nonproliferation and safeguards aspects of the DUPIC fuel cycle concept

Energy Technology Data Exchange (ETDEWEB)

Persiani, P K [Argonne National Lab., IL (United States)

1997-07-01

The purpose of the study is to comment on the proliferation characteristic profiles of some of the proposed fuel cycle alternatives to help ensure that nonproliferation concerns are introduced into the early stages of a fuel cycle concept development program, and to perhaps aid in the more effective implementation of the international nonproliferation regime initiative and safeguards systems. Alternative recycle concepts proposed by several countries involve the recycle of spent fuel without the separation of plutonium from uranium and fission products. The concepts are alternatives to either the direct long-term storage deposition of or the purex reprocessing of the spent fuels. The alternate fuel cycle concepts reviewed include: the dry-recycle processes such as the direct use of reconfigured PWR spent fuel assemblies into CANDU reactors(DUPIC); low-decontamination, single-cycle co-extraction of fast reactor fuels in a wet-purex type of reprocessing; and on a limited scale the thorium-uranium fuel cycle. The nonproliferation advantages usually associated with the above non-separation processes are: the highly radioactive spent fuel presents a barrier to the physical diversion of the nuclear material; avoid the need to dissolve and chemically separate the plutonium from the uranium and fission products; and that the spent fuel isotopic quality of the plutonium vector is further degraded. Although the radiation levels and the need for reprocessing may be perceived as barriers to the terrorist or the subnational level of safeguards, the international level of nonproliferation concerns is addressed primarily by material accountancy and verification activities. On the international level of nonproliferation concerns, the non-separation fuel cycle concepts involved have to be evaluated on the bases of the impact the processes may have on nuclear materials accountancy. (author).

Competitive emissions of InAs (QDs)/GaInAsP/InP grown by GSMBE

Energy Technology Data Exchange (ETDEWEB)

Yuan, Xiaowen [Huazhong University of Science and Technology, Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Wuhan (China); Chinese Academy of Sciences, National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Shanghai (China); Wang, Qi; Li, Senlin; Chen, C.Q. [Huazhong University of Science and Technology, Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Wuhan (China); Sun, Liaoxin; Luo, X.D.; Zhang, Bo [Chinese Academy of Sciences, National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Shanghai (China)

2015-04-01

In this letter, the optical properties of InAs (QDs)/GaInAsP on InP substrate grown by gas source molecular beam epitaxy are investigated. By measuring and analyzing the photoluminescence spectra of InAs (QDs)/GaInAsP/InP at different temperatures and excitation powers, the origin of each emission is verified. And it is found that, with the temperature increasing, the emission intensity of GaInAsP wetting layers decreases firstly (T < 150 K) and then increases from 160 K to room temperature. By analyzing the experimental results of three samples with different QDs' sizes, a competitive emission between InAs QDs and GaInAsP wetting layers is confirmed. (orig.)

Elastic properties and electron transport in InAs nanowires

Energy Technology Data Exchange (ETDEWEB)

Migunov, Vadim

2013-02-22

The electron transport and elastic properties of InAs nanowires grown by chemical vapor deposition on InAs (001) substrate were studied experimentally, in-situ in a transmission electron microscope (TEM). A TEM holder allowing the measurement of a nanoforce while simultaneous imaging nanowire bending was used. Diffraction images from local areas of the wire were recorded to correlate elastic properties with the atomic structure of the nanowires. Another TEM holder allowing the application of electrical bias between the nanowire and an apex of a metallic needle while simultaneous imaging the nanowire in TEM or performing electron holography was used to detect mechanical vibrations in mechanical study or holographical observation of the nanowire inner potential in the electron transport studies. The combination of the scanning probe methods with TEM allows to correlate the measured electric and elastic properties of the nanowires with direct identification of their atomic structure. It was found that the nanowires have different atomic structures and different stacking fault defect densities that impacts critically on the elastic properties and electric transport. The unique methods, that were applied in this work, allowed to obtain dependencies of resistivity and Young's modulus of left angle 111 right angle -oriented InAs nanowires on defect density and diameter. It was found that the higher is the defect density the higher are the resistivity and the Young's modulus. Regarding the resistivity, it was deduced that the stacking faults increase the scattering of the electrons in the nanowire. These findings are consistent with the literature, however, the effect described by the other groups is not so pronounced. This difference can be attributed to the significant incompleteness of the physical models used for the data analysis. Regarding the elastic modulus, there are several mechanisms affecting the elasticity of the nanowires discussed in the thesis. It

Asia nuclear-test-ban network for nuclear non-proliferation

International Nuclear Information System (INIS)

Shinohara, Nobuo; Kokaji, Lisa; Ichimasa, Sukeyuki

2010-01-01

In Global Center of Excellence Program of The University of Tokyo, Non- Proliferation Study Committee by the members of nuclear industries, electricity utilities, nuclear energy institutes and universities has initiated on October 2008 from the viewpoints of investigating a package of measures for nuclear non-proliferation and bringing up young people who will support the near-future nuclear energy system. One of the non-proliferation issues in the Committee is the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Objective of this treaty is to cease all nuclear weapon test explosions and all other nuclear explosion. This purpose should be contributed effectively to the political stability of the Asian region by continuous efforts to eliminate the nuclear weapons. In the Committee, by extracting several issues related to the CTBT, conception of 'Asia nuclear-test-ban network for nuclear non-proliferation' has been discussed with the aim of the nuclear-weapon security in Asian region, where environmental nuclear-test monitoring data is mainly treated and utilized. In this paper, the conception of the 'network' is presented in detail. (author)

Nuclear power generation and nuclear nonproliferation

International Nuclear Information System (INIS)

Walske, C.

1978-01-01

In the future outlook around year 2000 of nuclear power, thought must be given to fuel reprocessing and plutonium utilization. The adverse utilization of plutonium may be prevented by the means balanced with its economical value. As the method of less cost with lower effect of nonproliferation, combination of fuel reprocessing and fuel fabrication facilities and mixed plutonium/uranium processing are possible. As the method of more cost with higher effect of nonproliferation the maintenance of high radioactivity and inaccessibility of plutonium is conceivable. As for the agreeable methods in 2000, seven principles may be mentioned, such as the dependence upon the agreements among major nations and upon nuclear exporting countries. These are still inadequate, however. What is important is to provide with the sufficient safeguards to countries concerned to negate the need for nuclear weapons. Efforts are then necessary for leading nuclear countries to extend aids to other nuclear-oriented countries. (Mori, K.)

Evaluation method of nuclear nonproliferation credibility

International Nuclear Information System (INIS)

Kwon, Eun-ha; Ko, Won Il

2009-01-01

This paper presents an integrated multicriteria analysis method for the quantitative evaluation of a state's nuclear nonproliferation credibility level. Underscoring the implications of policy on the sources of political demand for nuclear weapons rather than focusing on efforts to restrict the supply of specific weapons technology from the 'haves' to the 'have-nots', the proposed methodology considers the political, social, and cultural dimensions of nuclear proliferation. This methodology comprises three steps: (1) identifying the factors that influence credibility formation and employing them to construct a criteria tree that will illustrate the relationships among these factors; (2) defining the weight coefficients of each criterion through pairwise comparisons of the Analytical Hierarchy Process (AHP); and (3) assigning numerical scores to a state under each criterion and combining them with the weight coefficients in order to provide an overall assessment of the state. The functionality of this methodology is examined by assessing the current level of nuclear nonproliferation credibility of four countries: Japan, North Korea, South Korea, and Switzerland.

Establishment of Japan Atomic Energy Agency and strategy for nuclear non-proliferation studies

International Nuclear Information System (INIS)

Senzaki, Masao; Kurasaki, Takaaki; Inoue, Naoko

2005-01-01

Japan Atomic Energy Agency (JAEA) was established on October 1, 2005, after the merger of Japan Atomic Energy Research Institute and Japan Nuclear Cycle Development Institute. JAEA is the only governmental nuclear research and development institute in Japan. It will engage in research activities ranging from basic research to practical applications in the nuclear field and will operate research laboratories, reactors, a reprocessing plant and a fuel fabrication plant. At the same time, the Nuclear Nonproliferation Science and Technology Center (NPSTC) was also established inside of JAEA to conduct the studies on the strategy for nuclear nonproliferation studies. Five roles that JAEA should play for nuclear nonproliferation were identified and four offices were established in the center to carry out those five roles effectively. To conduct the research and development for nuclear nonproliferation efficiently, the center aims to be a 'Research Hub' based on Partnership' with other organizations. (author)

Etching and oxidation of InAs in planar inductively coupled plasma

Energy Technology Data Exchange (ETDEWEB)

Dultsev, F.N., E-mail: fdultsev@thermo.isp.nsc.ru [Institute of Semiconductor Physics SB RAS, Lavrentiev av. 13, Novosibirsk 630090 (Russian Federation); Kesler, V.G. [Institute of Semiconductor Physics SB RAS, Lavrentiev av. 13, Novosibirsk 630090 (Russian Federation)

2009-10-15

The surface of InAs (1 1 1)A was investigated under plasmachemical etching in the gas mixture CH{sub 4}/H{sub 2}/Ar. Etching was performed using the RF (13.56 MHz) and ICP plasma with the power 30-150 and 50-300 W, respectively; gas pressure in the reactor was 3-10 mTorr. It was demonstrated that the composition of the subsurface layer less than 5 nm thick changes during plasmachemical etching. A method of deep etching of InAs involving ICP plasma and hydrocarbon based chemistry providing the conservation of the surface relief is proposed. Optimal conditions and the composition of the gas phase for plasmachemical etching ensuring acceptable etch rates were selected.

Etching and oxidation of InAs in planar inductively coupled plasma

Science.gov (United States)

Dultsev, F. N.; Kesler, V. G.

2009-10-01

The surface of InAs (1 1 1)A was investigated under plasmachemical etching in the gas mixture CH 4/H 2/Ar. Etching was performed using the RF (13.56 MHz) and ICP plasma with the power 30-150 and 50-300 W, respectively; gas pressure in the reactor was 3-10 mTorr. It was demonstrated that the composition of the subsurface layer less than 5 nm thick changes during plasmachemical etching. A method of deep etching of InAs involving ICP plasma and hydrocarbon based chemistry providing the conservation of the surface relief is proposed. Optimal conditions and the composition of the gas phase for plasmachemical etching ensuring acceptable etch rates were selected.

Etching and oxidation of InAs in planar inductively coupled plasma

International Nuclear Information System (INIS)

Dultsev, F.N.; Kesler, V.G.

2009-01-01

The surface of InAs (1 1 1)A was investigated under plasmachemical etching in the gas mixture CH 4 /H 2 /Ar. Etching was performed using the RF (13.56 MHz) and ICP plasma with the power 30-150 and 50-300 W, respectively; gas pressure in the reactor was 3-10 mTorr. It was demonstrated that the composition of the subsurface layer less than 5 nm thick changes during plasmachemical etching. A method of deep etching of InAs involving ICP plasma and hydrocarbon based chemistry providing the conservation of the surface relief is proposed. Optimal conditions and the composition of the gas phase for plasmachemical etching ensuring acceptable etch rates were selected.

The National Ignition Facility (NIF) and the issue of nonproliferation. Final study

International Nuclear Information System (INIS)

1995-01-01

NIF, the next step proposed by DOE in a progression of Inertial Confinement Fusion (ICF) facilities, is expected to reach the goal of ICF capsule ignition in the laboratory. This report is in response to a request of a Congressman that DOE resolve the question of whether NIF will aid or hinder U.S. nonproliferation efforts. Both technical and policy aspects are addressed, and public participation was part of the decision process. Since the technical proliferation concerns at NIF are manageable and can be made acceptable, and NIF can contribute positively to U.S. arms control and nonproliferation policy goals, it is concluded that NIF supports the nuclear nonproliferation objectives of the United States

The National Ignition Facility (NIF) and the issue of nonproliferation. Final study

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-19

NIF, the next step proposed by DOE in a progression of Inertial Confinement Fusion (ICF) facilities, is expected to reach the goal of ICF capsule ignition in the laboratory. This report is in response to a request of a Congressman that DOE resolve the question of whether NIF will aid or hinder U.S. nonproliferation efforts. Both technical and policy aspects are addressed, and public participation was part of the decision process. Since the technical proliferation concerns at NIF are manageable and can be made acceptable, and NIF can contribute positively to U.S. arms control and nonproliferation policy goals, it is concluded that NIF supports the nuclear nonproliferation objectives of the United States.

Growth and electrical characterization of Zn-doped InAs and InAs{sub 1-x}Sb{sub x}

Energy Technology Data Exchange (ETDEWEB)

Venter, A., E-mail: andre.venter@nmmu.ac.z [Department of Physics, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth (South Africa); Shamba, P.; Botha, L.; Botha, J.R. [Department of Physics, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth (South Africa)

2009-06-01

The electrical properties of Zn doped InAs and InAsSb layers grown on semi-insulating GaAs by metal organic vapour phase epitaxy, using dimethyl zinc as the p-type dopant source, have been studied. The influence of dopant flow rate, V/III ratio and substrate orientation on the electrical properties of these InAs and InAs{sub 1-x}Sb{sub x} layers have been studied at a few appropriate growth temperatures. A promising group V source, tertiary butyl arsenic was used as an alternative to arsenic hydride in the case of InAs growth. The electrical properties of the InAs and InAs{sub 1-x}Sb{sub x} epitaxial layers were mainly studied by the Hall effect. However, surface accumulation in these materials results in deceptive Hall results being extracted. A two layer model (assuming the layer to consist of two parallel conducting paths viz. surface and bulk) has therefore been used to extract sensible transport properties. In addition, conventional Hall measurements ignores the high electron to hole mobility ratio in InAs and InAsSb leading to erroneous transport properties.

Sensing Responses Based on Transfer Characteristics of InAs Nanowire Field-Effect Transistors

Science.gov (United States)

Savelyev, Igor; Blumin, Marina; Wang, Shiliang; Ruda, Harry E.

2017-01-01

Nanowire-based field-effect transistors (FETs) have demonstrated considerable promise for a new generation of chemical and biological sensors. Indium arsenide (InAs), by virtue of its high electron mobility and intrinsic surface accumulation layer of electrons, holds properties beneficial for creating high performance sensors that can be used in applications such as point-of-care testing for patients diagnosed with chronic diseases. Here, we propose devices based on a parallel configuration of InAs nanowires and investigate sensor responses from measurements of conductance over time and FET characteristics. The devices were tested in controlled concentrations of vapour containing acetic acid, 2-butanone and methanol. After adsorption of analyte molecules, trends in the transient current and transfer curves are correlated with the nature of the surface interaction. Specifically, we observed proportionality between acetic acid concentration and relative conductance change, off current and surface charge density extracted from subthreshold behaviour. We suggest the origin of the sensing response to acetic acid as a two-part, reversible acid-base and redox reaction between acetic acid, InAs and its native oxide that forms slow, donor-like states at the nanowire surface. We further describe a simple model that is able to distinguish the occurrence of physical versus chemical adsorption by comparing the values of the extracted surface charge density. These studies demonstrate that InAs nanowires can produce a multitude of sensor responses for the purpose of developing next generation, multi-dimensional sensor applications. PMID:28714903

Geometric factors in the magnetoresistance of n-doped InAs epilayers

KAUST Repository

Sun, Jian

2013-11-27

We investigate the magnetoresistance (MR) effect in n-doped InAs and InAs/metal hybrid devices with geometries tailored to elucidate the physical mechanism and the role of geometry in the MR. Despite the isotropic Fermi surface in InAs, we observe a strong intrinsic MR in the InAs epilayer due to the existence of a surface conducting layer. Experimental comparison confirms that the extraordinary MR in the InAs/metal hybrids outperforms the orbital MR in the Corbino disk in terms of both the MR ratio and the magnetic field resolution. The results also indicate the advantage of a two-contact configuration in the hybrid devices over a four-contact one with respect to the magnetic field resolution. This is in contrast to previously reported results, where performance was evaluated in terms of the MR ratio and a four-contact configuration was found to be optimal. By applying Kohler\\'s rule, we find that at temperatures above 75 K the extraordinary MR violates Kohler\\'s rule, due to multiple relaxation rates, whereas the orbital MR obeys it. This finding can be used to distinguish the two geometric effects, the extraordinary MR and the orbital MR, from each other.

Critical surface phase of α2(2 × 4) reconstructed zig-zag chains on InAs(001)

Energy Technology Data Exchange (ETDEWEB)

Guo, Xiang [Department of Electronic Information Science and Technology, Guizhou University, Guizhou, Guiyang 550025 (China); Zhou, Xun [Department of Electronic Information Science and Technology, Guizhou University, Guizhou, Guiyang 550025 (China); School of Physics and Electronics Science, Guizhou Normal University, Guizhou, Guiyang 550001 (China); Wang, Ji-Hong [Department of Electronic Information Science and Technology, Guizhou University, Guizhou, Guiyang 550025 (China); Luo, Zi-Jiang [Department of Electronic Information Science and Technology, Guizhou University, Guizhou, Guiyang 550025 (China); School of Education Administration, Guizhou University of Finance and Economics, Guizhou, Guiyang 550004 (China); Zhou, Qing; Liu, Ke; Hu, Ming-Zhe [Department of Electronic Information Science and Technology, Guizhou University, Guizhou, Guiyang 550025 (China); Ding, Zhao, E-mail: zding@gzu.edu.cn [Department of Electronic Information Science and Technology, Guizhou University, Guizhou, Guiyang 550025 (China)

2014-07-01

The critical condition for InAs(001) surface phase transition has been studied, the surface phase transition of InAs(001) showed discontinuity with hysteresis cycle as a function of substrate temperature. A mixed reconstruction surface and zig-zag chain α2(2 × 4) reconstruction surface have been observed by scanning tunneling microscopy. Considering the interaction and dynamics of surface arsenic atoms, the zig-zag chains of α2(2 × 4) reconstruction were found to be actually caused by the selective adsorption and desorption of surface arsenic dimers, they played a critical role in the surface phase transition between (2 × 4) and (4 × 2). - Highlights: • Discontinuous surface phase transition phenomena on the flat InAs(001) surface • Nanoscale InAs(001) surface observed by scanning tunneling microscopy • “Zig-Zag” chains of α2(2 × 4) reconstruction • Critical role in the surface phase transition between (2 × 4) and (4 × 2)

Critical surface phase of α2(2 × 4) reconstructed zig-zag chains on InAs(001)

International Nuclear Information System (INIS)

Guo, Xiang; Zhou, Xun; Wang, Ji-Hong; Luo, Zi-Jiang; Zhou, Qing; Liu, Ke; Hu, Ming-Zhe; Ding, Zhao

2014-01-01

The critical condition for InAs(001) surface phase transition has been studied, the surface phase transition of InAs(001) showed discontinuity with hysteresis cycle as a function of substrate temperature. A mixed reconstruction surface and zig-zag chain α2(2 × 4) reconstruction surface have been observed by scanning tunneling microscopy. Considering the interaction and dynamics of surface arsenic atoms, the zig-zag chains of α2(2 × 4) reconstruction were found to be actually caused by the selective adsorption and desorption of surface arsenic dimers, they played a critical role in the surface phase transition between (2 × 4) and (4 × 2). - Highlights: • Discontinuous surface phase transition phenomena on the flat InAs(001) surface • Nanoscale InAs(001) surface observed by scanning tunneling microscopy • “Zig-Zag” chains of α2(2 × 4) reconstruction • Critical role in the surface phase transition between (2 × 4) and (4 × 2)

Pathogenic and Ice-Nucleation Active (INA) Bacteria causing Dieback of Willows in Short Rotation Forestry

Energy Technology Data Exchange (ETDEWEB)

Nejad, Pajand

2005-03-01

To find out whether bacteria isolated from diseased plant parts can be the main causal agent for the dieback appearing in Salix energy forestry plantations in Sweden during the last few years, and if the joint effects of bacteria and frost injury are synergistic, extensive sampling of shoots from diseased Salix plants was performed. We performed several laboratory and greenhouse investigations and used evaluation techniques on the functions of the Ice-Nucleation Active (INA) bacteria. We carried out a comparison between spring and autumn bacterial communities isolated from within (endophytically) and surface (epiphytically) plant tissues of Salix viminalis. Seasonal variation of bacteria in willow clones with different levels of frost sensitivity and symptoms of bacterial damage was also investigated. We further focussed on possible effect of fertilisation and nutrient availability on the bacterial community in relation to plant dieback in Estonian willow plantations. The identification and detection of INA bacteria which cause damage in combination with frost to willow (Salix spp) plants in late fall, winter and spring was performed using BIOLOG MicroPlate, biochemical tests, selective INA primers and 16S rDNA analysis. To distinguish the character for differentiation between these bacteria morphologically and with respect to growing ability different culture media were used. We studied the temperature, at which ice nucleation occurred for individual bacteria, estimated the population of INA bacteria, effect of growth limiting factors, and evaluated the effect of chemical and physical agents for disruption and possible inhibition of INA among individual bacterial strains. The concentration of carbon, nitrogen and phosphorus on INA is discussed. We demonstrate that among the bacterial isolates recovered from the willow plantations, there were many that were capable of ice nucleation at temperatures between -2 and -10 deg C, many that were capable of inducing a

Developing Effluent Analysis Technologies to Support Nonproliferation Initiatives, Arms Control and Nonproliferation Technologies, Third quarter 1995

Energy Technology Data Exchange (ETDEWEB)

Schubert, S A; Staehle, G; Alonzo, G M [eds.

1995-01-01

This issue provides an overview of the Effluent Research Program of the DOE Office of Research and Development, highlighting a number of representative projects within this program in support of nonproliferation initiatives. Technologies reported include portable instruments for on-site inspections, standoff detectors, fieldable, real-time instruments, field collection techniques, and ultrasensitive laboratory techniques.

Nonproliferation norms in civilian nuclear fuel cycle

International Nuclear Information System (INIS)

Kawata, Tomio

2005-01-01

For sustainable use of nuclear energy in large scale, it seems inevitable to choose a closed cycle option. One of the important questions is, then, whether we can really achieve the compatibility between civilian nuclear fuel cycle and nonproliferation norms. In this aspect, Japan is very unique because she is now only one country with full-scope nuclear fuel cycle program as a non-nuclear weapon state in NPT regime. In June 2004 in the midst of heightened proliferation concerns in NPT regime, the IAEA Board of Governors concluded that, for Japanese nuclear energy program, non-diversion of declared nuclear material and the absence of undeclared nuclear material and activities were verified through the inspections and examinations under Comprehensive Safeguards and the Additional Protocol. Based on this conclusion, the IAEA announced the implementation of Integrated Safeguards in Japan in September 2004. This paper reviews how Japan has succeeded in becoming the first country with full-scope nuclear fuel cycle program to qualify for integrated Safeguards, and identifies five key elements that have made this achievement happen: (1) Obvious need of nuclear fuel cycle program, (2) Country's clear intention for renunciation of nuclear armament, (3) Transparency of national nuclear energy program, (4) Record of excellent compliance with nonproliferation obligations for many decades, and (5) Numerous proactive efforts. These five key elements will constitute a kind of an acceptance model for civilian nuclear fuel cycle in NNWS, and may become the basis for building 'Nonproliferation Culture'. (author)

Electronic Structures of Strained InAs x P1-x by Density Functional Theory.

Science.gov (United States)

Lee, Seung Mi; Kim, Min-Young; Kim, Young Heon

2018-09-01

We investigated the effects of strain on the electronic structures of InAsxP1-x using quantum mechanical density functional theory calculations. The electronic band gap and electron effective mass decreased with the increase of the uniaxial tensile strain along the [0001] direction of wurtzite InAs0.75P0.25. Therefore, faster electron movements are expected. These theoretical results are in good agreement with the experimental measurements of InAs0.75P0.25 nanowire.

InAs migration on released, wrinkled InGaAs membranes used as virtual substrate

International Nuclear Information System (INIS)

Filipe Covre da Silva, S; Lanzoni, E M; De Araujo Barboza, V; Deneke, Ch; Malachias, A; Kiravittaya, S

2014-01-01

Partly released, relaxed and wrinkled InGaAs membranes are used as virtual substrates for overgrowth with InAs. Such samples exhibit different lattice parameters for the unreleased epitaxial parts, the released flat, back-bond areas and the released wrinkled areas. A large InAs migration towards the released membrane is observed with a material accumulation on top of the freestanding wrinkles during overgrowth. A semi-quantitative analysis of the misfit strain shows that the material migrates to the areas of the sample with the lowest misfit strain, which we consider as the areas of the lowest chemical potential of the surface. Material migration is also observed for the edge-supported, freestanding InGaAs membranes found on these samples. Our results show that the released, wrinkled nanomembranes offer a growth template for InAs deposition that fundamentally changes the migration behavior of the deposited material on the growth surface. (paper)

Electron microscopy of GaAs-based structures with InAs and As quantum dots separated by an AlAs barrier

International Nuclear Information System (INIS)

Nevedomskiy, V. N.; Bert, N. A.; Chaldyshev, V. V.; Preobrazhenskiy, V. V.; Putyato, M. A.; Semyagin, B. R.

2013-01-01

Electron microscopy studies of GaAs-based structures grown by molecular beam epitaxy and containing arrays of semiconductor InAs quantum dots and metal As quantum dots are performed. The array of InAs quantum dots is formed by the Stranski-Krastanov mechanism and consists of vertically coupled pairs of quantum dots separated by a GaAs spacer 10 nm thick. To separate the arrays of semiconductor and metal quantum dots and to prevent diffusion-induced mixing, the array of InAs quantum dots is overgrown with an AlAs barrier layer 5 or 10 nm thick, after which a GaAs layer is grown at a comparatively low temperature (180°C). The array of As quantum dots is formed in an As-enriched layer of the low-temperature GaAs by means of post-growth annealing at 400–760°C for 15 min. It is established that the AlAs barrier layer has a surface profile corresponding to that of a subbarrier layer with InAs quantum dots. The presence of such a profile causes the formation of V-shaped structural defects upon subsequent overgrowth with the GaAs layer. Besides, it was obtained that AlAs layer is thinned over the InAs quantum dots tops. It is shown that the AlAs barrier layer in the regions between the InAs quantum dots effectively prevents the starting diffusion of excess As at annealing temperatures up to 600°C. However, the concentration of mechanical stresses and the reduced thickness of the AlAs barrier layer near the tops of the InAs quantum dots lead to local barrier breakthroughs and the diffusion of As quantum dots into the region of coupled pairs of InAs quantum dots at higher annealing temperatures

Single-photon generation with InAs quantum dots

International Nuclear Information System (INIS)

Santori, Charles; Fattal, David; Vuckovic, Jelena; Solomon, Glenn S; Yamamoto, Yoshihisa

2004-01-01

Single-photon generation using InAs quantum dots in pillar microcavities is described. The effects on performance of the excitation wavelength and polarization, and the collection bandwidth and polarization, are studied in detail. The efficiency and photon state purity of these devices have been measured, and issues affecting these parameters are discussed. Prospects for improved devices are also discussed

Correlation between the Montreal Cognitive Assessment-Indonesian Version (Moca-INA) and the Mini-Mental State Examination (MMSE) in Elderly.

Science.gov (United States)

Rambe, Aldy Safruddin; Fitri, Fasihah Irfani

2017-12-15

As the rapid growth of the elderly population and the increased prevalence of Alezheimer's Disease and related disorders, there is an increasing need for effective cognitive screening. The Mini Mental State Examination (MMSE) is the most frequently used screening test of cognitive impairment because of its convenience. The Montreal Cognitive Assessment-Indonesian Version (MoCA-INA) has been validated and recently been used as a cognitive screening tool. The aim of this study was to compare the MMSE and MoCA-INA scores and to determine the correlation between the MMSE and MoCA-INA scores in elderly. This was a cross-sectional study including 83 elderly subjects from November 2016 until June 2017. We performed MMSE and MoCA-INA for assessment of cognitive function and the time between each test was at least 30 minutes. The study included 83 subjects which were consisted of 46 (55.4%) males and 37 (44.6%) females. The mean age was 69.19 ± 4.23 ranging from 65 to 79 years old. The average MMSE scores was 24.96 ± 3.38 (range 14 to 30). The average MoCA-INA scores was 21.06 ± 4.56 (range 5 to 30). The Pearson correlation coefficient between the scores was 0.71 (p<0.005). There were no significant differences of both scores based on history of hypertension, diabetes mellitus and previous stroke, but there was a significant difference in MMSE scores based on level of education. The MoCA-INA score showed a good correlation with the MMSE score. Both tests showed comparable results but MoCA-INA showed lower average with wider range of scores.

76 FR 68809 - Bureau of International Security and Nonproliferation; Termination of Chemical and Biological...

Science.gov (United States)

2011-11-07

..., Office of Missile, Biological, and Chemical Nonproliferation, Bureau of International Security and... DEPARTMENT OF STATE [Public Notice: 7678] Bureau of International Security and Nonproliferation; Termination of Chemical and Biological Weapons (CBW) Proliferation Sanctions Against a Foreign Person AGENCY...

Surface Preparation of InAs (110 Using Atomic Hydrogen

Directory of Open Access Journals (Sweden)

T.D. Veal

2002-06-01

Full Text Available Atomic hydrogen cleaning has been used to produce structurally and electronically damage-free InAs(110 surfaces.  X-ray photoelectron spectroscopy (XPS was used to obtain chemical composition and chemical state information about the surface, before and after the removal of the atmospheric contamination. Low energy electron diffraction (LEED and high-resolution electron-energy-loss spectroscopy (HREELS were also used, respectively, to determine the surface reconstruction and degree of surface ordering, and to probe the adsorbed contaminant vibrational modes and the collective excitations of the clean surface. Clean, ordered and stoichiometric  InAs(110-(1×1 surfaces were obtained by exposure to thermally generated atomic hydrogen at a substrate temperature as low as 400ºC.  Semi-classical dielectric theory analysis of HREEL spectra of the phonon and plasmon excitations of the clean surface indicate that no electronic damage or dopant passivation were induced by the surface preparation method.

How we think about peace and security. The ABCs of initiatives for disarmament and non-proliferation education

International Nuclear Information System (INIS)

Toki, Masako; Potter, William C.

2005-01-01

Education and training are among the most important but underutilized tools for promoting disarmament and non-proliferation. Although few national governments or international organizations have invested significantly in such training programs, there is a growing recognition among States of the need to rectify this situation. This positive development is reflected in the broad support for recommendations of a UN study on Disarmament and Non-Proliferation Education and in related initiatives within the review process of the Nuclear Non-Proliferation Treaty (NPT). In view of the forthcoming 2005 NPT Review Conference, it is useful to take stock of the implementation of the UN study's recommendations. In particular, it is important to observe the progress that has been made within the context of the NPT review process, as well as the obstacles that must be overcome if the full potential for disarmament and non-proliferation education is to be realized. Resources on disarmament and non-proliferation education are increasingly available on the Internet. The UN Department for Disarmament Affairs has launched new features on its web site that include links to academic institutes, governmental centers, NGOs and other bodies engaged in educational efforts. As part of its mission to combat the spread of weapons of mass destruction (WMD) by training the next generation of nonproliferation specialists and raising global public awareness on WMD issues, the Center for Nonproliferation Studies (CNS) has developed a series of tutorials for non-proliferation and disarmament education. Among these tutorials, the NPT Tutorial has been designed to educate and provide useful material about the treaty through interactive text and enriched multimedia segments, including timelines, maps, and numerous links to relevant resources. Among other resources are teaching guides developed by the Monterey Institute's Center for Nonproliferation Studies through its Critical Issues Forum (CIF). More

The international nuclear non-proliferation system: Challenges and choices

International Nuclear Information System (INIS)

Simpson, J.; McGrew, A.G.

1984-01-01

When a topic has been under discussion for almost 40 years there is a danger that the literature will become excessively esoteric and that, as Philip Grummett suggests, '...a new scholasticism will arise' (p.79). Originating in a November l982 seminar co-sponsored by the British International Studies Association and the Foreign and Commonwealth Office, this volume is a refreshing, well conceived, and well written antidote to that trend. It is also well timed for the 1985 NPT Review Conference. The eight chapters of the volume are divided into three sections. Following an introduction by Anthony McGrew that touches on all the major themes of the volume, the first section deals with the existing non-proliferation system. In three chapters the historical, institutional and policy-making elements of the present system are outlined. There is a vignette on the Nuclear Suppliers Group in Wilmshurst's chapter one (pp. 28-33). Fischer's informative chapter on the IAEA is followed by Gummett's examination of policy options, including, for example, the linking of conventional weapons transfer to non-proliferation policies. The second section, also of three chapters, examines current issues: the state of the international nuclear industry, and the non-proliferation policies of the United States and Britain. Walker's chapter focuses chiefly on change in the industry-from monopoly to pluralism in suppliers, the effect of the economic recession, and the combined effect of these two factors on international politics. Devine's American non-proliferation chapter is a statement of the State Department view, whilst Keohane's chapter on Britain attempts to put the Trident procurement into a proliferation context. The British chapter is present because of ethnocentric considerations

Reforming the non-proliferation system in the 1980s

International Nuclear Information System (INIS)

Wilmshurst, M.J.

1984-01-01

The non-proliferation policies of the 1970s were based largely on the misconception that the main danger lay in the possible misuse of civil nuclear-power plants for the production of weapon materials. In consequence their aim, whether by means of denial or control, was to ensure that such misuse was made more difficult in all countries with nuclear-power industries. Less attention was paid to the potential for misuse of the nuclear-research plants in the handful of countries outside the non-proliferation system. The resulting difficulties placed in the way of countries developing their nuclear-power industries damaged relations between the supplier and the consumer states, and discredited any new efforts aimed at strengthening the non-proliferation system. By contrast, the 1980s began, first in INFCE and then in the Committee on Assurances of Supply, with a concerted attempt to re-establish a dialogue based on a relationship of trust between the supplier and the customer states. But a restored consensus will not, on its own, deal with the problem of those states that are outside the non-proliferation system and that have the capability to produce nuclear weapons. The outcome of the work of the Committee on Assurances of Supply may help to attract some of those states into the system, but more needs to be done either by adapting the NPT, making adherence to it appear more attractive, or by devising some alternative code of behaviour for states not party to the Treaty and by seeking to remove the political obstacles that lie in the way of at least some of the potential weapon states adhering to the Treaty

Previewing the 2010 Nuclear Non-Proliferation Treaty Review Conference

International Nuclear Information System (INIS)

Pomper, Miles A.

2010-01-01

Despite groundbreaking disarmament pledges and substantial effort, the Obama administration's hopes for a successful Nuclear Non-Proliferation Treaty (NPT) Review Conference may not be fully realised. Many developing countries are in no mood to grant new non-proliferation concessions, such as tightened rules on access to sensitive nuclear technologies, tougher inspection rules, or limits on withdrawing from the treaty. The non-nuclear weapon states (NNWS) remain angered by the failure to move forward on many disarmament commitments pledged at the 1995 and 2000 Conferences. Moreover, progress on disarmament measures under Obama has been slower than hoped, as he faces considerable scepticism in Washington about his strategy. (author)

Joint DOE-PNC research on the use of transparency in support of Nuclear Nonproliferation

International Nuclear Information System (INIS)

Mochiji, Toshiro; Tazaki, Makiko; Keeney, Robin; Puckett, John; Stanbro, William; Nakhleh, Charles

1998-01-01

PNC and LANL collaborated in research on the concept of transparency in nuclear nonproliferation. The research was based on the Action Sheet no.21, which was signed in February 1996, 'The Joint Research on 'Transparency' in Nuclear Nonproliferation' under the 'Agreement between the Power Reactor and Nuclear Fuel Development Corporation of Japan (PNC) and the US Department of Energy (DOE) for Cooperation in Research and Development Concerning Nuclear Material Control and Accounting Measures for Safeguards and Nonproliferation.' The scope of the research was a fundamental study on transparency to clarify the means to improve worldwide acceptability of nuclear energy from a nuclear nonproliferation viewpoint. The research encompassed three main topics: the policy environment of transparency, the development of transparency options, and technical options for transparency. Each side performed independent research then joint workshops were held to exchange information and views. This paper summarizes the results of these workshops. (author)

Activities of the study group of peaceful uses of nuclear energy and non-proliferation policy. FY Heisei 11

International Nuclear Information System (INIS)

Kurosawa, Mitsuru; Oi, Noboru

2000-01-01

The Study Group on the Peaceful Uses of Nuclear Energy and Non-Proliferation Policy (Chairman: Prof. Kurosawa) was established in FY1999 with the funding from the Science and Technology Agency. The aim of the Study Group is to clearly understand nuclear proliferation issues and to lead international opinion. Nuclear non-proliferation is a matter of rather scanty interest compared to nuclear safety while both of them are important in promoting peaceful uses of nuclear energy in Japan. In FY2000, the Study Group held International Symposium 'Peaceful Uses of Nuclear Energy and Non-Proliferation: A Challenge of 21st Century' and in conjunction with this Symposium, dispatched 'The Statement on the Peaceful Uses of Nuclear Energy and Non-Proliferation, Action Plan towards 21st Century'. The Statement consists of five propositions: 1) Strengthening the global nuclear non-proliferation regime and making it universally applicable, 2) Negative legacy of cold war: rapid solution of problems, 3) Civil (non-military) plutonium, 4) Development of technology to strengthen the nuclear non-proliferation regime internationally, and 5) Strengthening Japanese initiative on nuclear non-proliferation policy. In this report, these activities will be explained in detail. (author)

The Non-Proliferation Treaty increases security

International Nuclear Information System (INIS)

Kahiluoto, K.

1995-01-01

Extension of the Nuclear Non-Proliferation Treaty indefinitely was a historic decision. The Treaty is the most extensive international agreement on security policy to date; now its obligations have become a permanent part of international justice. Moreover, the NPT represents a political and moral obligation. Through the NPT, the international community has made a permanent commitment to restrict the proliferation of nuclear weapons. Increasing pressures will be applied to the few countries still outside the NPT, making it more likely that these countries will eventually change their views. The likelihood of regional bans on nuclear weapons in the Middle East and in Asia, too, will increase. The Treaty promotes the establishment of new nuclear-free zones. The nuclear-free zone in Latin America - the countries covered by the Tlatelolco Treaty - is already very close to its full implementation. Finland is firmly committed to the obligations of the Non-Proliferation Treaty. The NPT Conference of 1995 was among the first international meetings in which Finland participated, and took an active role, as a Member State of the European Union. (orig.)

Nuclear Nonproliferation Ontology Assessment Team Final Report

Energy Technology Data Exchange (ETDEWEB)

Strasburg, Jana D.; Hohimer, Ryan E.

2012-01-01

Final Report for the NA22 Simulations, Algorithm and Modeling (SAM) Ontology Assessment Team's efforts from FY09-FY11. The Ontology Assessment Team began in May 2009 and concluded in September 2011. During this two-year time frame, the Ontology Assessment team had two objectives: (1) Assessing the utility of knowledge representation and semantic technologies for addressing nuclear nonproliferation challenges; and (2) Developing ontological support tools that would provide a framework for integrating across the Simulation, Algorithm and Modeling (SAM) program. The SAM Program was going through a large assessment and strategic planning effort during this time and as a result, the relative importance of these two objectives changed, altering the focus of the Ontology Assessment Team. In the end, the team conducted an assessment of the state of art, created an annotated bibliography, and developed a series of ontological support tools, demonstrations and presentations. A total of more than 35 individuals from 12 different research institutions participated in the Ontology Assessment Team. These included subject matter experts in several nuclear nonproliferation-related domains as well as experts in semantic technologies. Despite the diverse backgrounds and perspectives, the Ontology Assessment team functioned very well together and aspects could serve as a model for future inter-laboratory collaborations and working groups. While the team encountered several challenges and learned many lessons along the way, the Ontology Assessment effort was ultimately a success that led to several multi-lab research projects and opened up a new area of scientific exploration within the Office of Nuclear Nonproliferation and Verification.

Romania non-proliferation policy

International Nuclear Information System (INIS)

Biro, Lucian; Grama, Viviana

2001-01-01

Full text: Non-proliferation concept in Romania is based on the Treaty on the Non-proliferation of Nuclear Weapons, which was ratified in 1970. According to the Article III of the Treaty, Romania ratified in 1972, the Agreement between Romania and IAEA for the application of Safeguards in connection with the Treaty on the Non-proliferation of Nuclear Weapons. In 2000 Romania ratified the Additional Protocol to contribute through increased transparency, to confidence that no undeclared nuclear activities are concealed within the declared programme or make use of elements of that programme. Under the Additional Protocol Romania understands to increase the transparency of its nuclear activities lengthways fuel cycle. Romania has a strong legal framework to control nuclear material and nuclear activities. The Law 111/1996, republished is the Law on the safe deployment of nuclear activities. CNCAN issued National Regulations for Safeguards and Physical Protection. Prospecting for uranium in Romania was initiated in 1950. Between 1962 and 1978 all the uranium ore production was stockpiled at the mine sites. In 1978 the Feldioara Powder Plant was commissioned, since then both ore stockpiles and ore exploited have been processed to uranium chemical concentrates. The Powder Plant Feldioara was conceived and built following the necessity of milling and processing the uranium ore to UO 2 , in concordance with the national nuclear programme in order to produce electric energy from nuclear fuel. The Nuclear Fuel Plant has capability to manufacture CANDU-6 nuclear fuel. Nuclear Fuel Plant consists of two Production areas, the Quality Assurance and Engineering Departments. There are two Production Departments: Pelleting area including granulation, pressing, sintering, pellet grinding, uranium recycling and Assembling area including components fabrication, beryllium coating, brazing, graphite coating, fuel element and bundle assembly welding. Romania's Strategy for Energy Sector

Consideration on non-proliferation regime meeting in a changing world

International Nuclear Information System (INIS)

Kurihara, Hiroyoshi; Kikuchi, Masahiro

1995-01-01

This paper presents some proposals for improvement of non-proliferation regime including safeguards structures with historical changes of international regime. Current non-proliferation regime was established under the circumstances of Cold War, and it's structure and measures were influenced by the situation of these time. Although, a couple of years have passed from end of Cold War, new world order has not established yet. Therefore, it is expected that the current regime could be improved in accordance with new world order. Generally speaking, it could be welcomed that the current regime has got some successes from two points of views, namely no new nuclear weapon states have emerged and after the establishment of NPT and all nuclear weapon state is joined NPT finally. However, it is the authors' concern that some gray countries, such as India, Pakistan and Israel, have not joined the NPT yet and cases of Iraqi and DPRK have occurred. After reviewing of such new situation, some proposals will be presented in order to strengthen the nonproliferation regime to meet current world conditions

Infrasonic measurements of the Non-Proliferation Experiment

Energy Technology Data Exchange (ETDEWEB)

Whitaker, R.W.; Noel, S.; Meadows, W. [Los Alamos National Laboratory, NM (United States)

1994-12-31

Two infrasonic arrays were operated for the Non-Proliferation Experiment (NPE). The arrays were located at the Nevada Test Site and at St. George, UT. The results were consistent with experience on underground tests, and therefore close to underground nuclear tests of similar size.

EMP at the Non-Proliferation Experiment

Energy Technology Data Exchange (ETDEWEB)

Bell, J. [AWE, Aldermaston (United Kingdom)

1994-12-31

This experiment presented an opportunity to field customized equipment designed to detect and record electromagnetic pulse (EMP) emanations from an explosion over a wide frequency range. Any data recorded could be used in conjunction with the seismic methods to further non-proliferation studies. No EMP emanations were detectable from the four sensors deployed outside the tunnel confines.

Fe-contacts on InAs(100) and InP(100) characterised by conversion electron Mössbauer spectroscopy

DEFF Research Database (Denmark)

Damsgaard, Christian Danvad; Gunnlaugsson, H.P; Weyer, G.

2005-01-01

We have grown 4 nm thin films of Fe-57 on InAs(100) and InP(100) surfaces by use of MBE and studied the samples by Fe-57 conversion electron Mossbauer spectroscopy. In the case of InAs, the Mossbauer spectrum showed a sextet due to alpha-Fe and a further magnetically split component with slightly...

Non-proliferation through effective international control. Report of working group I

International Nuclear Information System (INIS)

Miller, S.E.

1993-01-01

Working Group I focused on two issues: the nuclear non-proliferation regime and the Missile Technology Regime (MTCR). There was wide agreement within the Group on a number of factors that will strongly influence the prospects for the Non-proliferation Treaty (NPT) extension Conference. Two points stood out as particularly important: first, emphasis on the obligations for nuclear Powers to move in good faith in direction of nuclear disarmament; and second, inadequacy of security guarantees to non-nuclear States associated with the NPT

United Nations study on disarmament and non-proliferation education

International Nuclear Information System (INIS)

2003-01-01

Science and technology transformed the world in the twentieth century. Living standards improved but warfare was rendered more deadly. Weapons of mass destruction - biological, chemical and nuclear - and their means of delivery were developed, as ever more sophisticated conventional armaments were produced and disseminated. The horrors and destruction of armed conflict persist. The need for disarmament and non-proliferation education and training has never been greater. Indeed, changing concepts and perceptions of security and threat magnify the urgency for new thinking to pursue disarmament and non-proliferation goals. More than a decade after the end of the cold war and at the start of the twenty- first century, there is a pressing need to combat ignorance, complacency and a culture of violence. These can be countered through long-term programmes of education and training, especially those related to disarmament and non- proliferation of weapons of mass destruction and their means of delivery, with a view to their reduction and complete elimination. At the same time, concern has heightened over the global threat of the excessive and destabilizing proliferation of conventional weapons, especially small arms and light weapons, rendering more acute the need to combat such proliferation in a sustained way through disarmament and non-proliferation education and training. Additionally there is a need to raise awareness of new challenges to international security and the process of disarmament. Among them, terrorism, with the possibility of the use of weapons of mass destruction, is a source of particular concern. Other challenges, such as organized crime, poverty, human rights abuses and environmental concerns must also be taken into account. Education and training remain important but under utilized tools for promoting peace, disarmament and non-proliferation. The present report addresses that issue and proposes ideas for action

The international nuclear non-proliferation system: Challenges and choices

Energy Technology Data Exchange (ETDEWEB)

Simpson, J.; McGrew, A.G.

1984-01-01

When a topic has been under discussion for almost 40 years there is a danger that the literature will become excessively esoteric and that, as Philip Grummett suggests, '...a new scholasticism will arise' (p.79). Originating in a November l982 seminar co-sponsored by the British International Studies Association and the Foreign and Commonwealth Office, this volume is a refreshing, well conceived, and well written antidote to that trend. It is also well timed for the 1985 NPT Review Conference. The eight chapters of the volume are divided into three sections. Following an introduction by Anthony McGrew that touches on all the major themes of the volume, the first section deals with the existing non-proliferation system. In three chapters the historical, institutional and policy-making elements of the present system are outlined. There is a vignette on the Nuclear Suppliers Group in Wilmshurst's chapter one (pp. 28-33). Fischer's informative chapter on the IAEA is followed by Gummett's examination of policy options, including, for example, the linking of conventional weapons transfer to non-proliferation policies. The second section, also of three chapters, examines current issues: the state of the international nuclear industry, and the non-proliferation policies of the United States and Britain. Walker's chapter focuses chiefly on change in the industry-from monopoly to pluralism in suppliers, the effect of the economic recession, and the combined effect of these two factors on international politics. Devine's American non-proliferation chapter is a statement of the State Department view, whilst Keohane's chapter on Britain attempts to put the Trident procurement into a proliferation context. The British chapter is present because of ethnocentric considerations.

How Might Industry Governance Be Broadened To Include Nonproliferation

International Nuclear Information System (INIS)

Hund, Gretchen; Seward, Amy M.

2009-01-01

Broadening industry governance to support nonproliferation could provide significant new leverage in preventing the spread/diversion of nuclear, radiological, or dual-use material or technology that could be used in making a nuclear or radiological weapon. Industry is defined broadly to include (1) the nuclear industry, (2) dual-use industries, and (3) radioactive source manufacturers and selected radioactive source-user industries worldwide. This paper describes how industry can be an important first line of defense in detecting and thwarting proliferation, such as an illicit trade network or an insider theft case, by complementing and strengthening existing governmental efforts. For example, the dual-use industry can play a critical role by providing export, import, or security control information that would allow a government or the International Atomic Energy Agency (IAEA) to integrate this information with safeguards, export, import, and physical protection information it has to create a more complete picture of the potential for proliferation. Because industry is closest to users of the goods and technology that could be illicitly diverted throughout the supply chain, industry information can potentially be more timely and accurate than other sources of information. Industry is in an ideal position to help ensure that such illicit activities are detected. This role could be performed more effectively if companies worked together within a particular industry to promote nonproliferation by implementing an industry-wide self-regulation program. Performance measures could be used to ensure their materials and technologies are secure throughout the supply chain and that customers are legitimately using and/or maintaining oversight of these items. Nonproliferation is the overarching driver that industry needs to consider in adopting and implementing a self-regulation approach. A few foreign companies have begun such an approach to date; it is believed that

The nuclear non-proliferation international system before the TNP revision conference (1995)

International Nuclear Information System (INIS)

Biad, A.

1996-01-01

This document described the international cooperation on nuclear non-proliferation. It consists of different agreements which aim at a pacific use of nuclear energy. However it is shown that many difficulties occurred during the non-proliferation treaty. Questions on equilibrium between control and cooperation, on the link between nuclear weapons reduction and countries equipped with the weapon, on the security for non-equipped countries are separately discussed. (TEC)

On the processing of InAs and InSb photodiode applications

Energy Technology Data Exchange (ETDEWEB)

Odendaal, V.; Botha, J.R. [Department of Physics, Nelson Mandela Metropolitan University, PO Box 77000, Nelson Mandela Metropolitan University, Port Elizabeth 6031 (South Africa); Auret, F.D. [Department of Physics, University of Pretoria, Lynnwood road, Hillcrest, Pretoria 0002 (South Africa)

2008-07-01

In this paper, potential methods for the surface passivation of InSb and InAs material, covering both compositional extremes of the promising narrow band gap semiconductor InAsSb, are evaluated. Surface states, mostly due to dangling bonds and exposure to the atmosphere, create generation-recombination centres that negatively influence the dark current, stability, efficiency and related noise characteristics of photosensitive devices fabricated from these materials. The effect of various surface treatments, including sulphuric acid based etching, lactic acid based etching, KOH anodising and Na{sub 2}S anodising, on the relative number of surface states is deduced by evaluating the capacitance versus voltage characteristics of metal-insulator-semiconductor structures fabricated on InAs and InSb. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

On the processing of InAs and InSb photodiode applications

International Nuclear Information System (INIS)

Odendaal, V.; Botha, J.R.; Auret, F.D.

2008-01-01

In this paper, potential methods for the surface passivation of InSb and InAs material, covering both compositional extremes of the promising narrow band gap semiconductor InAsSb, are evaluated. Surface states, mostly due to dangling bonds and exposure to the atmosphere, create generation-recombination centres that negatively influence the dark current, stability, efficiency and related noise characteristics of photosensitive devices fabricated from these materials. The effect of various surface treatments, including sulphuric acid based etching, lactic acid based etching, KOH anodising and Na 2 S anodising, on the relative number of surface states is deduced by evaluating the capacitance versus voltage characteristics of metal-insulator-semiconductor structures fabricated on InAs and InSb. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

The role of strain-driven in migration in the growth of self-assembled InAs quantum dots on InP

CERN Document Server

Yoon, S H; Lee, T W; Hwang, H D; Yoon, E J; Kim, Y D

1999-01-01

Self-assembled InAs quantum dots (SAQDs) were grown on InP by metalorganic chemical vapor deposition. The amount of excess InAs and the aspect ratio of the SAQD increased with temperature and V/III ratio. It is explained that the As/P exchange reaction at the surface played an important role in the kinetics of SAQD formation. Insertion of a lattice-matched InGaAs buffer layer suppressed the excess InAs formation, and lowered the aspect ratio. Moreover, the dots formed on InGaAs buffer layers were faceted, whereas those on InP were hemispherical, confirming the effect of the As/P exchange reaction. The shape of InAs quantum dots on InGaAs buffer layers was a truncated pyramid with four [136] facets and base edges parallel to directions.

The Crystal structure of InAs nanorods grown onto Si[111] substrate

Energy Technology Data Exchange (ETDEWEB)

Davydok, Anton; Biermanns, Andreas; Pietsch, Ullrich [Festkoerperphysik, Universitaet Siegen, Walter-Flex-Str. 3,57072, Siegen (Germany); Breuer, Steffen; Dimakis, Manos; Geelhaar, Lutz [Paul-Drude-Institut fuer Festkoerperelektronik, Hausvogteiplatz 5-7, 10117 Berlin (Germany)

2011-07-01

Nanowires are of particular interest due to the ability to synthesize heterostructures in the nanometer range. It was found that nearly any AIIIBV semiconductor material can be grown as NWs onto another AIIIBV or group IV [111] substrate independent from lattice mismatch. We presented an X-ray characterization of InAs NRs on Si [111] grown by assist free MBE method. Lattice mismatch of this materials is 11%. For study of strain realizing we concentrated our research on initial stages of growth process investigating samples set with different growth time. Using synchrotron radiation we have performed experiments in symmetrical and asymmetrical out-of plane scattering geometry and grazing-incidence diffraction. Combining the results we were able to characterize the transition between silicon silicon substrate and InAs NWs. We find in-plane lattice mismatch of -0.18% close to the interface compared to InAs bulk material. With help of micro-focus setup we are able measure structural parameters of single NWs to determine the strain accomodation as function of NW size. In particular using asymmetric wurzite-sensitive reflections under coherent beam illumination we could quantify the number of stacking faults. In the talk we present details of the analysis and first simulation results.

Sovereignty and non-proliferation policy

International Nuclear Information System (INIS)

Kimminich, O.

1990-01-01

The Non-Proliferation Treaty seems to violate the fundamental principle of the quality of the states. However, if interpreted in the light of the latest developments of the international law, it is possible to justify the discriminations which it imposes on the non-nuclear states. A crucial point is the implementation of article VI by the nuclear states. If the latter procrastinate in nuclear disarmament the whole NPT-regime will collapse. (orig.) [de

Activities of the ANS special committee on nuclear nonproliferation

International Nuclear Information System (INIS)

Buckner, M.R.; Sanders, T.L.

2001-01-01

The American Nuclear Society (ANS) Special Committee on Nuclear Nonproliferation (SCNN) believes that to reverse current trends, U.S. policy must revisit the fundamental premise of Atoms for Peace: A collaborative nuclear enterprise enhances rather than diminishes national security. To accomplish this, the U.S. Government must develop an integrated policy on energy, nuclear technology, and national security. The policy must recognize that these are interrelated and that an integrated policy will require substantial investments in nuclear research and development and in nuclear education. This paper describes the current activities of the SCNN to heighten awareness of nonproliferation issues for decision makers and ANS members, and alert them to the need for action to resolve these concerns. (author)

Activities of the ANS special committee on nuclear nonproliferation

Energy Technology Data Exchange (ETDEWEB)

Buckner, M.R. [Westinghouse Savannah River Co., Aiken, SC (United States); Sanders, T.L. [Sandia National Labs., Albuquerque, NM (United States)

2001-07-01

The American Nuclear Society (ANS) Special Committee on Nuclear Nonproliferation (SCNN) believes that to reverse current trends, U.S. policy must revisit the fundamental premise of Atoms for Peace: A collaborative nuclear enterprise enhances rather than diminishes national security. To accomplish this, the U.S. Government must develop an integrated policy on energy, nuclear technology, and national security. The policy must recognize that these are interrelated and that an integrated policy will require substantial investments in nuclear research and development and in nuclear education. This paper describes the current activities of the SCNN to heighten awareness of nonproliferation issues for decision makers and ANS members, and alert them to the need for action to resolve these concerns. (author)

Physical protection and its role in nuclear non-proliferation

International Nuclear Information System (INIS)

Nilsson, A.

1999-01-01

Non-proliferation of nuclear weapons has been one of the main concerns of the international community since the first nuclear weapons were developed. To prevent the proliferation of nuclear weapons has been on the agenda for individual States, groups of States and the international organizations. A number of treaties, conventions and agreements, the most important being the Non-Proliferation Treaty, have been negotiated to prevent the horizontal proliferation of nuclear weapons. States have concluded safeguards agreements with the IAEA to fulfill their obligations according to Article III.1 of the NPT. Other agreements relate to the prevention of vertical proliferation and also to the disarmament of nuclear weapons. It has also been recognized that sub-national, terrorist, or criminal activities may pose a proliferation risk. Illicit trafficking of nuclear material, particularly highly enriched uranium or plutonium, is a non-proliferation concern. States have recognized the need to prevent, as far as possible, the use of nuclear material in unlawful activities. The Convention of Physical Protection of Nuclear Materials, obligates the State Parties to protect nuclear material from theft during international transport, and to make unlawful possession, use, etc., of nuclear material a criminal offense, subject to punishment under national law. Although the physical protection convention recognizes the importance of the physical protection of nuclear material in domestic use, storage and transport, it does not obligate the State party to establish the necessary systems for this purpose. It is this limitation which led many States to believe that the international physical protection regime needs to be strengthened. Although not legally binding per se, the recommendations documented in INFCIRC/225/Rev. 4, The Physical Protection of Nuclear Material and Nuclear Facilities, has obtained wide recognition. There is recognition among States that protecting nuclear material

15 CFR Supplement No. 1 to Part 742 - Nonproliferation of Chemical and Biological Weapons

Science.gov (United States)

2010-01-01

... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Nonproliferation of Chemical and...—Nonproliferation of Chemical and Biological Weapons Note: Exports and reexports of items in performance of.... Contract sanctity dates are established in the course of the imposition of foreign policy controls on...

Non-proliferation and nuclear cooperation - accomplishments and challenges

International Nuclear Information System (INIS)

Marshall, H.R. Jr.

1983-01-01

The purpose of this paper is to assess the accomplishments in non-proliferation and nuclear co-operation since the beginning of President Reagan's administration, and the challenges remaining to be met in those fields. (NEA) [fr

99mTc-MIBI/123I-Na subtraction scanning for localized parathyroid adenoma in patients with asymptomatic/mild primary hyperparathyroidism

International Nuclear Information System (INIS)

Tanaka, Yuji; Funahashi, Hiroomi; Imai, Tsuneo

1996-01-01

Primary hyperparathyroidism is most commonly detected as a mild elevation of the serum calcium concentration. In the present study, the utility of 99m Tc-methoxyisobutylisonitrile (MIBI) imaging before initial surgery was evaluated for localizing abnormal parathyroid glands in patients with asymptomatic and mild primary hyperparathyroidism. The results were compared with those of thallium-technetium subtraction scanning (TTSS). 99m Tc-MIBI/ 123 I-Na subtraction scanning was performed in 11 patients, and TTSS was performed in 10 of them. The sensitivity was 100% and the positive predictive value was 92% for 99m Tc-MIBI/ 123 I-Na, while the sensitivity was 50% and the positive predictive value was 100% for TTSS. The smallest gland detected weighed 85 mg in 99m Tc-MIBI/ 123 I-Na, and 570 mg in TTSS. There was a difference between the median weight of adenomas which were detected by 99m Tc-MIBI/ 123 I-Na (754 mg), and those which were detected by TTSS (1,195 mg). These results suggest that TTSS parathyroid scintigraphy could give way to 99m Tc-MIBI/ 123 I-Na parathyroid scintigraphy for improved detection of low-weight abnormal parathyroid glands. (author)

InP and InAs nanowires hetero- and homojunctions: energetic stability and electronic properties.

Science.gov (United States)

Dionízio Moreira, M; Venezuela, P; Miwa, R H

2010-07-16

We performed an ab initio total energy investigation, within the density functional theory, of the energetic stability and the electronic properties of hydrogenated InAs/InP nanowire (NW) heterojunctions, as well as InAs and InP homojunctions composed of different structural arrangements, zinc-blend (zb) and wurtzite (w). For InAs/InP NW heterojunctions our results indicate that w and zb NW heterojunctions are quite similar, energetically, for thin NWs. We also examined the robustness of the abrupt interface through an atomic swap at the InAs/InP interface. Our results support the formation of abrupt (non-abrupt) interfaces in w (zb) InAs/InP heterojunctions. Concerning InAs/InP NW-SLs, our results indicate a type-I band alignment, with the energy barrier at the InP layers, in accordance with experimental works. For InAs or InP zb/w homojunctions, we also found a type-I band alignment for thin NWs, however, on increasing the NW diameter both InAs and InP homojunctions exhibit a type-II band alignment.

InP and InAs nanowires hetero- and homojunctions: energetic stability and electronic properties

International Nuclear Information System (INIS)

Dionizio Moreira, M; Venezuela, P; Miwa, R H

2010-01-01

We performed an ab initio total energy investigation, within the density functional theory, of the energetic stability and the electronic properties of hydrogenated InAs/InP nanowire (NW) heterojunctions, as well as InAs and InP homojunctions composed of different structural arrangements, zinc-blend (zb) and wurtzite (w). For InAs/InP NW heterojunctions our results indicate that w and zb NW heterojunctions are quite similar, energetically, for thin NWs. We also examined the robustness of the abrupt interface through an atomic As↔P swap at the InAs/InP interface. Our results support the formation of abrupt (non-abrupt) interfaces in w (zb) InAs/InP heterojunctions. Concerning InAs/InP NW-SLs, our results indicate a type-I band alignment, with the energy barrier at the InP layers, in accordance with experimental works. For InAs or InP zb/w homojunctions, we also found a type-I band alignment for thin NWs, however, on increasing the NW diameter both InAs and InP homojunctions exhibit a type-II band alignment.

Approaches to nuclear disarmament and non-proliferation

International Nuclear Information System (INIS)

Subrahmanyam, K.

1981-01-01

The logic behind the approach of the nuclear weapon states (NWS) to the issue of nuclear disarmament and non-proliferation is based on: (1) The assumption that the less the number of decision makers who could initiate a nuclear war less the probability of war, (2) the claim of the NWS that their nuclear weapons are under strict control, and (3) the claim of the NWS who have signed the Non-Proliferation Treaty (NPT) that the Treaty is being scrupulously observed by them. This logic is critically examined in the light of disclosures that indicate that: (1) both vertical and horizontal proliferation is going on without respite among the NWS, and (2) the fissile material is clandestinely being allowed to be diverted to the favoured clients by one or more of the NWS. These NWS are not subject to any safeguards under the NPT. They are using the NPT and the concept of nuclear free zone as a sort of tactic to divert the attention from the correct approach to the disarmament and to impose their hegemony over the Third World Countries. Moreover, the NPT has conferred a sort of legitimacy to the possession of nuclear weapons by the NWS. In these circumstances their preaching to the Third World countries about nuclear disarmament and non-proliferation sounds hypocritical. The correct approach to these issues would be to put the nuclear weapons under the category of weapons of mass destruction and to ban their use under a non-discriminatory international convention as has been done in the case of biological and chemical weapons. (M.G.B.)

High uniformity of self-organized InAs quantum wires on InAlAs buffers grown on misoriented InP(001)

International Nuclear Information System (INIS)

Wang Yuanli; Jin, P.; Ye, X.L.; Zhang, C.L.; Shi, G.X.; Li, R.Y.; Chen, Y.H.; Wang, Z.G.

2006-01-01

Highly uniform InAs quantum wires (QWRs) have been obtained on the In 0.5 Al 0.5 As buffer layer grown on the InP substrate 8 (convolutionsign) off (001) towards (111) by molecular-beam epitaxy. The quasi-periodic composition modulation was spontaneously formed in the In 0.5 Al 0.5 As buffer layer on this misoriented InP (001). The width and period of the In-rich bands are about 10 and 40 nm, respectively. The periodic In-rich bands play a major role in the sequent InAs QWRs growth and the InAs QWRs are well positioned atop In-rich bands. The photoluminescence (PL) measurements showed a significant reduction in full width at half maximum and enhanced PL efficiency for InAs QWRs on misoriented InP(001) as compared to that on normal InP(001)

Charge pumping in InAs nanowires by surface acoustic waves

NARCIS (Netherlands)

Roddaro, Stefano; Strambini, Elia; Romeo, Lorenzo; Piazza, Vincenzo; Nilsson, Kristian; Samuelson, Lars; Beltram, Fabio

2010-01-01

We investigate the interaction between surface acoustic waves on a piezoelectric LiNbO3 substrate and charge carriers in InAs nanowire transistors. Interdigital transducers are used to excite electromechanical waves on the chip surface and their influence on the transport in the nanowire devices is

Crystal-phase intergradation in InAs nanostructures grown by van der Waals heteroepitaxy on graphene

Science.gov (United States)

Choi, Ji Eun; Yoo, Jinkyoung; Lee, Donghwa; Hong, Young Joon; Fukui, Takashi

2018-04-01

This study demonstrates the crystal-phase intergradation of InAs nanostructures grown on graphene via van der Waals epitaxy. InAs nanostructures with diverse diameters are yielded on graphene. High-resolution transmission electron microscopy (HR-TEM) reveals two crystallographic features of (i) wurtzite (WZ)-to-zinc blende (ZB) intergradation along the growth direction of InAs nanostructures and (ii) an increased mean fraction of ZB according to diameter increment. Based on the HR-TEM observations, a crystal-phase intergradation diagram is depicted. We discuss how the formation of a WZ-rich phase during the initial growth stage is an effective way of releasing heterointerfacial stress endowed by the lattice mismatch of InAs/graphene for energy minimization in terms of less in-plane lattice mismatching between WZ-InAs and graphene. The WZ-to-ZB evolution is responsible for the attenuation of the bottom-to-top surface charge interaction as growth proceeds.

Nuclear non-proliferation: a guide to the debate

International Nuclear Information System (INIS)

Goldblat, Jozef.

1985-01-01

The non-proliferation policies of 15 countries have been studied and summarized for use by participants of the third Review Conference of the Parties to the Treaty on the Non-Proliferation (NPT) of Nuclear weapons held in September 1985. The main purpose of the guide is to examine what action must be taken to ensure the Treaty's survival. There are four chapters following an introduction, covering the implementation of the essential provisions of the NPT, the motivations of the countries which have not joined the NPT, together with the motivations of those which have formally renounced the possession of nuclear weapons, even though they possess the technical and economic potential necessary to manufacture them. The last chapter summarises measures which might be taken to strengthen the NPT including ideas put forward at a workshop held in 1984. (author)

Experience of Republic of Macedonia in Providing WMD Non-Proliferation Policy

International Nuclear Information System (INIS)

Mecinovic, S.

2007-01-01

The Republic of Macedonia as a country in transition and as a country which does not posses WMD, has accepted to developed and implemented non-proliferation policy of WMD. First of all, we accepted the definition of WMD as used in international agreements, conventions and protocol and WMD includes nuclear, biological and toxin weapons, agent and precursors. WMD in wide sense includes all toxic chemical substances if they are used as means of attack or if they are the target of attack, all microorganisms and their product, all industrial facilities that use toxic chemicals in their process of production, transport and stockpile if they are a target of military or terrorist attack. For WMD non-proliferation projects to be valid, they must be on the level and carry the weight of international policy and doctrine and involve a most comprehensive sphere of the scientific and professional communities. This is only way to implement the projects in country such is Republic of Macedonia where the public opinion is that WMD are not real security problem because we neither possess nor seek to posses these kinds of weapons. Our WMD non-proliferation policy is tied to control of weapons, agents, precursors, technology and their transfer, market and possibility of use. Because of that we try to control know terrorist organization, groups and individuals. Terrorism caused special concern and attention, particularly when we talk about terrorism with NBC weapons and radiological, chemical and biological warfare agents. Scientific and technological progress led to fact that the instruments for performing terrorism (including WMD) can be produced or procured much easier than before. Rising industry which uses toxic chemicals and microorganisms in the production process created a lot of potential targets for terrorism actions in which they can use be as a target and an executive instrument. The new goal of contemporary treats is safety of life environment, which today includes

Report of the international forum on nuclear energy, nuclear non-proliferation and nuclear security. Measures to ensure nuclear non-proliferation and nuclear security for the back end of nuclear fuel cycle and regional cooperation in Asia

International Nuclear Information System (INIS)

Tazaki, Makiko; Yamamura, Tsukasa; Suzuki, Mitsutoshi; Kuno, Yusuke; Mochiji, Toshiro

2013-03-01

The Japan Atomic Energy Agency (JAEA) held 'International Forum on Nuclear Energy, Nuclear Non-proliferation and Nuclear Security - Measures to ensure nuclear non-proliferation and nuclear security for the back end of nuclear fuel cycle and regional cooperation in Asia-' on 12 and 13 December 2012, co-hosted by the Japan Institute of International Affairs (JIIA) and School of Engineering, The University of Tokyo. In the forum, keynote speakers from Japan, International Atomic Energy Agency (IAEA), the U.S., France and Republic of Korea (ROK), respectively explained their efforts regarding peaceful use of nuclear energy and nuclear non-proliferation. In two panel discussions, entitled 'Measures to ensure nuclear non-proliferation and nuclear security of nuclear fuel cycle back end' and 'Measures to ensure nuclear non-proliferation and nuclear security for nuclear energy use in the Asian region and a multilateral cooperative framework', active discussions were made among panelists from Japan, IAEA, the U.S., France, ROK, Russia and Kazakhstan. This report includes abstracts of keynote speeches, summaries of two panel discussions and materials of the presentations in the forum. The editors take full responsibility for the wording and content of this report except presentation materials. (author)

Diameter dependence of the thermal conductivity of InAs nanowires

NARCIS (Netherlands)

Swinkels, M.Y.; van Delft, M.R.; Oliveira, D.S.; Cavalli, A.; Zardo, I.; van der Heijden, R.W.; Bakkers, E.P.A.M.

2015-01-01

The diameter dependence of the thermal conductivity of InAs nanowires in the range of 40–1500 nm has been measured. We demonstrate a reduction in thermal conductivity of 80% for 40 nm nanowires, opening the way for further design strategies for nanoscaled thermoelectric materials. Furthermore, we

Non-proliferation efforts in South Asia

International Nuclear Information System (INIS)

Chellaney, B.

1994-01-01

Southern Asia is one of the most volatile regions in the world because of inter-State and intra-State conflicts. Security in the region highly depends on the rival capabilities of the involved states, Pakistan, India, China. Increased Confidence building and nuclear transparency are becoming more significant issues in attaining stability in the region, although non-proliferation efforts in this region have attained little headway

Characterization of multilayer self-organized InAs quantum dot embedded waveguides at 1.3 and 1.5 μm

NARCIS (Netherlands)

Akca, I.B.; Dana, A.; Aydinli, A.; Rossetti, M.; Li, L.; Fiore, A.; Dagli, N.

2007-01-01

In this paper, we characterized the electro-optic coefficient and loss of multilayer InAs quantum dot laser structures at 1309 and 1515 nm. Quantum dot waveguides were grown by molecular beam epitaxy, where the active region is formed by three or five layers of self-assembled InAs QDs. Loss

Working Group 3: Broader Perspectives on Non-proliferation and Nuclear Verification

International Nuclear Information System (INIS)

Dreicer, M.; Pregenzer, A.; Stein, G.

2013-01-01

This working group (WG) focused on the technical topics related to international security and stability in global nonproliferation and arms control regimes and asked how nonproliferation tools and culture might facilitate verification of future nuclear treaties. The review of existing and future nonproliferation and disarmament regimes (Comprehensive Test Ban Treaty - CTBT, UNSC Resolution 1540, UK/Norway/VERTIC exercise, Fissile Material Cut-off Treaty - FMCT) offered a view on challenges, possibilities, and limitations for future initiatives. The concepts that the WG considered, with potential use in implementing future nuclear verification treaties, are: Triple S Culture (Safety, Security, Safeguards), State-Level Approach, Safeguards-by-Design, risk-based approaches, managed access, inspections, and protection of sensitive information. Under these concepts, many existing tools, considered by the WG could be used for nuclear verification. Export control works to control sensitive technology and expertise. Global implementation is complicated and multi-faceted and would benefit from greater consistency and efficiency. In most cases, international cooperation and development international capability would supplement efforts. This document is composed of the slides and the paper of the presentation. (A.C.)

INTEGRATION OF FACILITY MODELING CAPABILITIES FOR NUCLEAR NONPROLIFERATION ANALYSIS

Energy Technology Data Exchange (ETDEWEB)

Gorensek, M.; Hamm, L.; Garcia, H.; Burr, T.; Coles, G.; Edmunds, T.; Garrett, A.; Krebs, J.; Kress, R.; Lamberti, V.; Schoenwald, D.; Tzanos, C.; Ward, R.

2011-07-18

Developing automated methods for data collection and analysis that can facilitate nuclear nonproliferation assessment is an important research area with significant consequences for the effective global deployment of nuclear energy. Facility modeling that can integrate and interpret observations collected from monitored facilities in order to ascertain their functional details will be a critical element of these methods. Although improvements are continually sought, existing facility modeling tools can characterize all aspects of reactor operations and the majority of nuclear fuel cycle processing steps, and include algorithms for data processing and interpretation. Assessing nonproliferation status is challenging because observations can come from many sources, including local and remote sensors that monitor facility operations, as well as open sources that provide specific business information about the monitored facilities, and can be of many different types. Although many current facility models are capable of analyzing large amounts of information, they have not been integrated in an analyst-friendly manner. This paper addresses some of these facility modeling capabilities and illustrates how they could be integrated and utilized for nonproliferation analysis. The inverse problem of inferring facility conditions based on collected observations is described, along with a proposed architecture and computer framework for utilizing facility modeling tools. After considering a representative sampling of key facility modeling capabilities, the proposed integration framework is illustrated with several examples.

Integration of facility modeling capabilities for nuclear nonproliferation analysis

International Nuclear Information System (INIS)

Garcia, Humberto; Burr, Tom; Coles, Garill A.; Edmunds, Thomas A.; Garrett, Alfred; Gorensek, Maximilian; Hamm, Luther; Krebs, John; Kress, Reid L.; Lamberti, Vincent; Schoenwald, David; Tzanos, Constantine P.; Ward, Richard C.

2012-01-01

Developing automated methods for data collection and analysis that can facilitate nuclear nonproliferation assessment is an important research area with significant consequences for the effective global deployment of nuclear energy. Facility modeling that can integrate and interpret observations collected from monitored facilities in order to ascertain their functional details will be a critical element of these methods. Although improvements are continually sought, existing facility modeling tools can characterize all aspects of reactor operations and the majority of nuclear fuel cycle processing steps, and include algorithms for data processing and interpretation. Assessing nonproliferation status is challenging because observations can come from many sources, including local and remote sensors that monitor facility operations, as well as open sources that provide specific business information about the monitored facilities, and can be of many different types. Although many current facility models are capable of analyzing large amounts of information, they have not been integrated in an analyst-friendly manner. This paper addresses some of these facility modeling capabilities and illustrates how they could be integrated and utilized for nonproliferation analysis. The inverse problem of inferring facility conditions based on collected observations is described, along with a proposed architecture and computer framework for utilizing facility modeling tools. After considering a representative sampling of key facility modeling capabilities, the proposed integration framework is illustrated with several examples.

Integration Of Facility Modeling Capabilities For Nuclear Nonproliferation Analysis

International Nuclear Information System (INIS)

Gorensek, M.; Hamm, L.; Garcia, H.; Burr, T.; Coles, G.; Edmunds, T.; Garrett, A.; Krebs, J.; Kress, R.; Lamberti, V.; Schoenwald, D.; Tzanos, C.; Ward, R.

2011-01-01

Developing automated methods for data collection and analysis that can facilitate nuclear nonproliferation assessment is an important research area with significant consequences for the effective global deployment of nuclear energy. Facility modeling that can integrate and interpret observations collected from monitored facilities in order to ascertain their functional details will be a critical element of these methods. Although improvements are continually sought, existing facility modeling tools can characterize all aspects of reactor operations and the majority of nuclear fuel cycle processing steps, and include algorithms for data processing and interpretation. Assessing nonproliferation status is challenging because observations can come from many sources, including local and remote sensors that monitor facility operations, as well as open sources that provide specific business information about the monitored facilities, and can be of many different types. Although many current facility models are capable of analyzing large amounts of information, they have not been integrated in an analyst-friendly manner. This paper addresses some of these facility modeling capabilities and illustrates how they could be integrated and utilized for nonproliferation analysis. The inverse problem of inferring facility conditions based on collected observations is described, along with a proposed architecture and computer framework for utilizing facility modeling tools. After considering a representative sampling of key facility modeling capabilities, the proposed integration framework is illustrated with several examples.

An Introduction to Nuclear Non-Proliferation and Safeguards

International Nuclear Information System (INIS)

Haakansson, Ane; Jonter, Thomas

2007-06-01

The purpose of this project was to compile a course material that covers how the nuclear safeguards system has emerged and how it works today. The produced compendium is directed to both university students and people concerned by safeguards from the industry. The primary aim of the first part of this paper is to describe the historical development of this global non-proliferation system and its central tasks. A second purpose is to discuss the advantages and disadvantages of its current design in order to answer the following question: Can we today say that we have a functioning global non-proliferation system? Does it require further strengthening, and, if so, how can this be achieved? In the second section we review the verification regime within nuclear safeguards, i. e. describe the methods and techniques that are available to reassure the world community that concluded treaties are adhered to

An Introduction to Nuclear Non-Proliferation and Safeguards

Energy Technology Data Exchange (ETDEWEB)

Haakansson, Ane; Jonter, Thomas

2007-06-15

The purpose of this project was to compile a course material that covers how the nuclear safeguards system has emerged and how it works today. The produced compendium is directed to both university students and people concerned by safeguards from the industry. The primary aim of the first part of this paper is to describe the historical development of this global non-proliferation system and its central tasks. A second purpose is to discuss the advantages and disadvantages of its current design in order to answer the following question: Can we today say that we have a functioning global non-proliferation system? Does it require further strengthening, and, if so, how can this be achieved? In the second section we review the verification regime within nuclear safeguards, i. e. describe the methods and techniques that are available to reassure the world community that concluded treaties are adhered to

Legislation to amend the Nuclear Non-Proliferation Act of 1978. Hearings and markup before the Committee on Foreign Affairs and its Subcommittees on International Security and Scientific Affairs, and on International Economic Policy and Trade of the House of Representatives, Ninety-Seventh Congress, Second Session on H.R. 6032 and H.R. 6318, August 3, 10; September 8, 15; and December 14, 1982

International Nuclear Information System (INIS)

Anon.

1983-01-01

Witnesses evaluated the effectiveness of non-proliferation policies during five days of hearings on H.R. 6032 and H.R. 6318 amending the Nuclear Non-Proliferation Act (NNPA) of 1978. The objective is to retain US leadership in nuclear trade while strengthening restrictions that retard the proliferation of weapons-grade material. They examined the economic benefits of new policy initiatives which permit foreign countries to reprocess and recycle US-supplied fuel and permit US companies to export reprocessing technology. The 19 witnesses spoke for the nuclear industry, organizations involved in arms control, and the administration. The 30 appendices include the texts of H.R. 6032, H.R. 6318, and H.R. 7430 and other comments and materials submitted for the record

New evolution of safeguards and non-proliferation

International Nuclear Information System (INIS)

Seyama, K.; Kurihara, H.

1999-01-01

Since the end of the Cold War, circumstances concerning international safeguards and nuclear non-proliferation have changed drastically. At this stage, early introduction of a strengthened and streamlined new safeguards system and broad implementation of the verification activities regarding nuclear material from dismantled nuclear weapons are expected, and in the near future, the international community is expected to establish a verification regime under the Cut Off Treaty. From now on, the roles of the IAEA will become more important in these new areas. At the same time the efficiency of the activities is essential from a financial and human resources aspect in order to introduce those measures smoothly. On the other hand, the Member States should cooperate with the IAEA to improve the transparency of its nuclear policy and activities. Taking account of such circumstances, first, the authors will explain the non-proliferation policy of Japan. Second, the authors will introduce the present status of Japan's safeguards system and activities. Finally, the authors will present several tasks which are important for the IAEA and Japanese safeguards for coming several years. (author)

Cooperative Remote Monitoring, Arms control and nonproliferation technologies: Fourth quarter 1995

Energy Technology Data Exchange (ETDEWEB)

Alonzo, G M [ed.

1995-01-01

The DOE`s Cooperative Remote Monitoring programs integrate elements from research and development and implementation to achieve DOE`s objectives in arms control and nonproliferation. The contents of this issue are: cooperative remote monitoring--trends in arms control and nonproliferation; Modular Integrated Monitoring System (MIMS); Authenticated Tracking and Monitoring Systems (ATMS); Tracking and Nuclear Materials by Wide-Area Nuclear Detection (WAND); Cooperative Monitoring Center; the International Remote Monitoring Project; international US and IAEA remote monitoring field trials; Project Dustcloud: monitoring the test stands in Iraq; bilateral remote monitoring: Kurchatov-Argonne-West Demonstration; INSENS Sensor System Project.

Argentina’s nuclear development and the non-proliferation regime

Directory of Open Access Journals (Sweden)

Sandra Colombo

2017-01-01

Full Text Available The development and transfer of nuclear technology have been put under strict control due to its possible military use, leading to the creation of international non-proliferation regimes. One of the latest proposals was the creation of multilateral banks of low enriched uranium (leu. The article states that, under the goal of non-proliferation, this initiative can contribute to accentuate the asymmetry in the distribution of world economic and political power, damaging the endogenous development of this technology in emerging countries. Against this, the article investigates the existence of margins to maneuver in the international system from the case of study of Argentina, one of the few developing countries that have managed to export nuclear technology, and has declared the development of independent nuclear activity as a State policy

Growth and anisotropic transport properties of self-assembled InAs nanostructures in InP

International Nuclear Information System (INIS)

Bierwagen, O.

2007-01-01

Self-assembled InAs nanostructures in InP, comprising quantum wells, quantum wires, and quantum dots, are studied in terms of their formation and properties. In particular, the structural, optical, and anisotropic transport properties of the nanostructures are investigated. The focus is a comprehending exploration of the anisotropic in-plane transport in large ensembles of laterally coupled InAs nanostructures. The self-assembled Stranski-Krastanov growth of InAs nanostructures is studied by gas-source molecular beam epitaxy on both nominally oriented and vicinal InP(001). Optical polarization of the interband transitions arising from the nanostructure type is demonstrated by photoluminescence and transmission spectroscopy. The experimentally convenient four-contact van der Pauw Hall measurement of rectangularly shaped semiconductors, usually applied to isotropic systems, is extended to yield the anisotropic transport properties. Temperature dependent transport measurements are performed in large ensembles of laterally closely spaced nanostructures. The transport of quantum wire-, quantum dash- and quantum dot containing samples is highly anisotropic with the principal axes of conductivity aligned to the directions. The direction of higher mobility is [ anti 110], which is parallel to the direction of the quantum wires. In extreme cases, the anisotropies exceed 30 for electrons, and 100 for holes. The extreme anisotropy for holes is due to diffusive transport through extended states in the [ anti 110], and hopping transport through laterally localized states in the [110] direction, within the same sample. A novel 5-terminal electronic switching device based on gate-controlled transport anisotropy is proposed. The gate-control of the transport anisotropy in modulation-doped, self-organized InAs quantum wires embedded in InP is demonstrated. (orig.)

Growth and anisotropic transport properties of self-assembled InAs nanostructures in InP

Energy Technology Data Exchange (ETDEWEB)

Bierwagen, O.

2007-12-20

Self-assembled InAs nanostructures in InP, comprising quantum wells, quantum wires, and quantum dots, are studied in terms of their formation and properties. In particular, the structural, optical, and anisotropic transport properties of the nanostructures are investigated. The focus is a comprehending exploration of the anisotropic in-plane transport in large ensembles of laterally coupled InAs nanostructures. The self-assembled Stranski-Krastanov growth of InAs nanostructures is studied by gas-source molecular beam epitaxy on both nominally oriented and vicinal InP(001). Optical polarization of the interband transitions arising from the nanostructure type is demonstrated by photoluminescence and transmission spectroscopy. The experimentally convenient four-contact van der Pauw Hall measurement of rectangularly shaped semiconductors, usually applied to isotropic systems, is extended to yield the anisotropic transport properties. Temperature dependent transport measurements are performed in large ensembles of laterally closely spaced nanostructures. The transport of quantum wire-, quantum dash- and quantum dot containing samples is highly anisotropic with the principal axes of conductivity aligned to the <110> directions. The direction of higher mobility is [ anti 110], which is parallel to the direction of the quantum wires. In extreme cases, the anisotropies exceed 30 for electrons, and 100 for holes. The extreme anisotropy for holes is due to diffusive transport through extended states in the [ anti 110], and hopping transport through laterally localized states in the [110] direction, within the same sample. A novel 5-terminal electronic switching device based on gate-controlled transport anisotropy is proposed. The gate-control of the transport anisotropy in modulation-doped, self-organized InAs quantum wires embedded in InP is demonstrated. (orig.)

INFCE and US non-proliferation policy

Energy Technology Data Exchange (ETDEWEB)

Donnelly, W H [Library of Congress, Washington, DC (USA)

1980-12-01

The International Fuel Cycle Evaluation (INFCE), which published its final reports in February 1980 produced a massive international effort of a kind never before seen. Over a period of two years its eight working groups held 61 meetings involving 519 experts from 46 countries and five international organizations. This article outlines the background and structure of INFCE and discusses how its recommendations diverge from US non-proliferation policy.

Carrier dynamics in InAs quantum dots embedded in InGaAs/GaAs multi quantum well structures

International Nuclear Information System (INIS)

Espinola, J L Casas; Dybic, M; Ostapenko, S; Torchynska, T V; Polupan, G

2007-01-01

Ground and multi excited state photoluminescence, as well as its temperature dependence, in InAs quantum dots embedded in symmetric In x Ga 1-x As/GaAs (x = 0.15) quantum wells (DWELL) have been investigated. The solution of the set of rate equations for exciton dynamics (relaxation into QWs or QDs and thermal escape) solved by us earlier is used for analysis the variety of thermal activation energies of photoluminescence thermal quenching for ground and multi excited states of InAs QDs. The obtained solutions were used at the discussion of the variety of activation energies of PL thermal quenching in InAs QDs. It is revealed three different regimes of thermally activated quenching of the QD PL intensity. These three regimes were attributed to thermal escape of excitons: i) from the high energy excited states of InAs QDs into the WL with follows exciton re-localization; ii) from the In x Ga 1-x As QWs into the GaAs barrier and iii) from the WL into the GaAs barrier with their subsequent nonradiative recombination in GaAs barrier

Calculation of Nonlinear Thermoelectric Coefficients of InAs1-xSbx Using Monte Carlo Method

Energy Technology Data Exchange (ETDEWEB)

Sadeghian, RB; Bahk, JH; Bian, ZX; Shakouri, A

2011-12-28

It was found that the nonlinear Peltier effect could take place and increase the cooling power density when a lightly doped thermoelectric material is under a large electrical field. This effect is due to the Seebeck coefficient enhancement from an electron distribution far from equilibrium. In the nonequilibrium transport regime, the solution of the Boltzmann transport equation in the relaxation-time approximation ceases to apply. The Monte Carlo method, on the other hand, proves to be a capable tool for simulation of semiconductor devices at small scales as well as thermoelectric effects with local nonequilibrium charge distribution. InAs1-xSb is a favorable thermoelectric material for nonlinear operation owing to its high mobility inherited from the binary compounds InSb and InAs. In this work we report simulation results on the nonlinear Peltier power of InAs1-xSb at low doping levels, at room temperature and at low temperatures. The thermoelectric power factor in nonlinear operation is compared with the maximum value that can be achieved with optimal doping in the linear transport regime.

Nuclear nonproliferation

International Nuclear Information System (INIS)

Neubert, M.

1992-01-01

The following motion was put before the United Kingdom House of Commons on 3rd February 1992 and agreed; that this House, recognising the potential dangers of the rapidly changing world order, welcomes the recent proposals for substantial reductions in nuclear weaponry, the growing support for the non-proliferation treaty and progress in the implementation of the United Nations Security Council Resolutions concerning the dismantling of Iraqi nuclear, chemical and biological capabilities; urges the Government to play their full part in helping the relevant authorities in the Commonwealth of Independent States to dismantle their nuclear devices, to safeguard their nuclear components and to discourage the proliferation of nuclear expertise; and believes it is of the first importance that Britain retains an effective and credible minimum nuclear deterrent as security in a world where there remain many sources of instability. The record of arguments for and against the motion in the debate is presented. (author)

Nuclear Safeguards and Electricity (Finance) Act 1978

International Nuclear Information System (INIS)

1978-01-01

This Act of 30 June 1978 gives effect to the Agreement concluded on 6 September 1976 between the United Kingdom, the European Atomic Energy Community and the International Atomic Energy Agency for the application of safeguards in the territory of the United Kingdom in connection with the Treaty on the Non-Proliferation of nuclear Weapons. It also deals with the financial support provided by the State for the generating station at Drax. (NEA) [fr

Reconstruction of an InAs nanowire using geometric tomography

DEFF Research Database (Denmark)

Pennington, Robert S.; König, Stefan; Alpers, Andreas

Geometric tomography and conventional algebraic tomography algorithms are used to reconstruct cross-sections of an InAs nanowire from a tilt series of experimental annular dark-field images. Both algorithms are also applied to a test object to assess what factors affect the reconstruction quality....... When using the present algorithms, geometric tomography is faster, but artifacts in the reconstruction may be difficult to recognize....

76 FR 81004 - Imposition of Nonproliferation Measures Against Foreign Persons, Including a Ban on U.S...

Science.gov (United States)

2011-12-27

... DEPARTMENT OF STATE [Public Notice: 7741] Imposition of Nonproliferation Measures Against Foreign... Nonproliferation, Department of State. ACTION: Notice. SUMMARY: A determination has been made that a number of foreign entities and one foreign person have engaged in activities that warrant the imposition of measures...

Reagan outlines nonproliferation policy

International Nuclear Information System (INIS)

Walsh, J.

1981-01-01

The Reagan Administration wants to shift from efforts to impose direct control over the fuel cycle and nuclear technology to a framework based on cooperation and initiatives for greater political stability. A nuclear-free zone for the Middle East is one area to explore. Congress responded to this announced plan with a counter move to tighten non-proliferation strategies. Reagan's policy will be to restore the US as an aggressive, but reliable nuclear trading partner operating under adequate safeguards. Critics find this approach dangerous and contradictory. The policy is still too general to answer specific questions about bilateral arrangements, generic permits, plutonium recycling, and other matters

Current nuclear non-proliferation policies in the world

International Nuclear Information System (INIS)

Kurosawa, Mitsuru

1997-01-01

Although a global nuclear confrontation between the U.S. and the Soviet Union has disappeared, many challenges to nuclear non-proliferation have emerged. Sources of concern, like a nuclear weapon program by Iraq and suspicions of North Korea have caused the adoption of a variety of political and technical measures in order to meet these challenges in the post-Cold War era. This paper describes the following ten policies for non-proliferation: 1) Strengthening the NPT; 2) Nuclear reduction; 3) CTBT and cut-off treaty; 4) Establishment of NWFZs; 5) Counterproliferation; 6) Strengthening the IAEA Safeguards; 7) Control and disposal of nuclear material from dismantled nuclear weapons; 8) Export control; 9) Registration of plutonium; and 10) Actions against nuclear smuggling. The first four measures can be said to be mainly political policies, the fifth measure (counterproliferation), can be categorized as basically a military policy, and the last five measures can be said to be technical. (J.P.N.)

The G1/S Specific Cyclin D2 Is a Regulator of HIV-1 Restriction in Non-proliferating Cells

Science.gov (United States)

Badia, Roger; Pujantell, Maria; Riveira-Muñoz, Eva; Puig, Teresa; Torres-Torronteras, Javier; Martí, Ramón; Clotet, Bonaventura; Ampudia, Rosa M.; Ballana, Ester

2016-01-01

Macrophages are a heterogeneous cell population strongly influenced by differentiation stimuli that become susceptible to HIV-1 infection after inactivation of the restriction factor SAMHD1 by cyclin-dependent kinases (CDK). Here, we have used primary human monocyte-derived macrophages differentiated through different stimuli to evaluate macrophage heterogeneity on cell activation and proliferation and susceptibility to HIV-1 infection. Stimulation of monocytes with GM-CSF induces a non-proliferating macrophage population highly restrictive to HIV-1 infection, characterized by the upregulation of the G1/S-specific cyclin D2, known to control early steps of cell cycle progression. Knockdown of cyclin D2, enhances HIV-1 replication in GM-CSF macrophages through inactivation of SAMHD1 restriction factor by phosphorylation. Co-immunoprecipitation experiments show that cyclin D2 forms a complex with CDK4 and p21, a factor known to restrict HIV-1 replication by affecting the function of the downstream cascade that leads to SAMHD1 deactivation. Thus, we demonstrate that cyclin D2 acts as regulator of cell cycle proteins affecting SAMHD1-mediated HIV-1 restriction in non-proliferating macrophages. PMID:27541004

Nuclear World Order and Nonproliferation

Energy Technology Data Exchange (ETDEWEB)

Joeck, N

2007-02-05

The decision by India and Pakistan in May 1998 to conduct nuclear weapon tests and declare themselves as nuclear weapon states challenged South Asian regional stability calculations, US nonproliferation policy, and prevailing assumptions about international security. A decade later, the effects of those tests are still being felt and policies are still adjusting to the changed global conditions. This paper will consider non- and counter-proliferation policy options for the United States and Pakistan as they work as partners to prevent the transfer of nuclear technology and further nuclear proliferation.

Adding GaAs Monolayers to InAs Quantum-Dot Lasers on (001) InP

Science.gov (United States)

Qiu, Yueming; Chacon, Rebecca; Uhl, David; Yang, Rui

2005-01-01

In a modification of the basic configuration of InAs quantum-dot semiconductor lasers on (001)lnP substrate, a thin layer (typically 1 to 2 monolayer thick) of GaAs is incorporated into the active region. This modification enhances laser performance: In particular, whereas it has been necessary to cool the unmodified devices to temperatures of about 80 K in order to obtain lasing at long wavelengths, the modified devices can lase at wavelengths of about 1.7 microns or more near room temperature. InAs quantum dots self-assemble, as a consequence of the lattice mismatch, during epitaxial deposition of InAs on ln0.53Ga0.47As/lnP. In the unmodified devices, the quantum dots as thus formed are typically nonuniform in size. Strainenergy relaxation in very large quantum dots can lead to poor laser performance, especially at wavelengths near 2 microns, for which large quantum dots are needed. In the modified devices, the thin layers of GaAs added to the active regions constitute potential-energy barriers that electrons can only penetrate by quantum tunneling and thus reduce the hot carrier effects. Also, the insertion of thin GaAs layer is shown to reduce the degree of nonuniformity of sizes of the quantum dots. In the fabrication of a batch of modified InAs quantum-dot lasers, the thin additional layer of GaAs is deposited as an interfacial layer in an InGaAs quantum well on (001) InP substrate. The device as described thus far is sandwiched between InGaAsPy waveguide layers, then further sandwiched between InP cladding layers, then further sandwiched between heavily Zn-doped (p-type) InGaAs contact layer.

The legal points at issue concerning the Non-proliferation Treaty and the verification agreement of EURATOM with the IAEA

International Nuclear Information System (INIS)

Zieger, G.

1975-01-01

An excellent and comprehensive but very juridicial contribution on: Development and content of the Non-proliferation Treaty, the problems which this Treaty poses for EURATOM (a common market, common supply, joint enterprises, Non-proliferation Treaty and France), the compatibility of the Non-proliferation Treaty with the EURATOM Treaty, verification agreement EURATOM - IAEA (the IAEA as the supervisory authority, the control system of the IAEA, guidelines elaborated by the IAEA to be used as the basis for negotiating safeguard agreements, national systems of accounting for and control of nuclear material IAEA supervision as a secondary control, principles of IAEA supervision, secrecy, conflict management), conclusion of the verification agreement, deviations from the guidelines elaborated by the IAEA to be used as the basis for negotiating safeguard agreements legal reflexions (verification agreement and Non-proliferation Treaty, reservations concerning the Non-proliferation Treaty, questions of competence between EURATOM and member states without nuclear weapons, problems of equal treatment). (HP/LN) [de

Nuclear non-proliferation: Revisiting the basics. Carnegie international non-proliferation conference 2002. Washington, D.C., 14 November 2002

International Nuclear Information System (INIS)

ElBaradei, M.

2002-01-01

The 1970 Treaty on the Non-Proliferation of Nuclear Weapons (NPT), with 188 States party, represents the cornerstone of the global nuclear non-proliferation and disarmament effort - and despite recent challenges, it has never been more relevant than it is today. But the international community has to move forward, it is essential that a number of the basic assumptions should be revisited, and a number of new approaches reconsidered. A key assumption at the core of the NPT was that the asymmetry between nuclear-weapon States and non-nuclear-weapon States would gradually disappear. The nuclear non-proliferation regime has overall been successful - but with some shortcomings. Efforts to end nuclear weapons development achieved an important milestone with the conclusion of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) in September 1996, but the pace of progress has been sluggish among the 44 countries whose ratification is required for the treaty to enter into force - and the rejection of the CTBT by the US Senate in 1999 was a distinct setback. Negotiation of a Fissile Material Cut-Off Treaty (FMCT) continues to languish in Geneva, more than seven years after agreement was reached on a mandate. The 2000 NPT Review Conference, building on the package of decisions and resolutions that led to the indefinite extension of the NPT in 1995, resulted in a number of encouraging commitments, not least the 'unequivocal undertaking' by the nuclear-weapon States to accomplish the total elimination of their nuclear arsenals. But a scant two years later, we have moved sharply away from those commitments, with a number of the '13 steps' toward nuclear disarmament - such as 'irreversibility,' 'START II, START III and the ABM Treaty,' further 'unilateral' reductions in nuclear arsenals, 'increased transparency,' 'further reduction of non-strategic nuclear weapons,' and 'regular reports' on the implementation of Article VI of the NPT - left without concrete follow-up actions and in

Second annual report on nuclear non-proliferation: supplement to Secretary's Annual Report to Congress

International Nuclear Information System (INIS)

1980-01-01

This document covers: goals of US nonproliferation policy, agreements for cooperation, technical exchange, US as a reliable supplier of nuclear fuels, IAEA Expert Group on International Plutonium Storage, implementation of US nonproliferation policy, classification, cooperation in strengthening international safeguards and physical security, the US-IAEA voluntary offer safeguards agreement, US spent fuel storage policy, development of proliferation-resistant fuel cycle technologies, and the International Nuclear Fuel Cycle Evaluation

Fermi energy dependence of the optical emission in core/shell InAs nanowire homostructures

Science.gov (United States)

Möller, M.; Oliveira, D. S.; Sahoo, P. K.; Cotta, M. A.; Iikawa, F.; Motisuke, P.; Molina-Sánchez, A.; de Lima, M. M., Jr.; García-Cristóbal, A.; Cantarero, A.

2017-07-01

InAs nanowires grown by vapor-liquid-solid (VLS) method are investigated by photoluminescence. We observe that the Fermi energy of all samples is reduced by ˜20 meV when the size of the Au nanoparticle used for catalysis is increased from 5 to 20 nm. Additional capping with a thin InP shell enhances the optical emission and does not affect the Fermi energy. The unexpected behavior of the Fermi energy is attributed to the differences in the residual donor (likely carbon) incorporation in the axial (low) and lateral (high incorporation) growth in the VLS and vapor-solid (VS) methods, respectively. The different impurity incorporation rate in these two regions leads to a core/shell InAs homostructure. In this case, the minority carriers (holes) diffuse to the core due to the built-in electric field created by the radial impurity distribution. As a result, the optical emission is dominated by the core region rather than by the more heavily doped InAs shell. Thus, the photoluminescence spectra and the Fermi energy become sensitive to the core diameter. These results are corroborated by a theoretical model using a self-consistent method to calculate the radial carrier distribution and Fermi energy for distinct diameters of Au nanoparticles.

Quantum efficiency and oscillator strength of site-controlled InAs quantum dots

DEFF Research Database (Denmark)

Albert, F.; Stobbe, Søren; Schneider, C.

2010-01-01

We report on time-resolved photoluminescence spectroscopy to determine the oscillator strength (OS) and the quantum efficiency (QE) of site-controlled InAs quantum dots nucleating on patterned nanoholes. These two quantities are determined by measurements on site-controlled quantum dot (SCQD...

Quantum Dots obtained by LPE from under-saturated In-As liquid phases on GaAs substrates

Energy Technology Data Exchange (ETDEWEB)

Ortiz F E; Mishurnyi V; Gorbatchev A; De Anda F [Universidad Autonoma de San Luis Potosi, Instituto de Investigacion en Comunicacion Optica, Av. Karacorum 1470, Col. Lomas 4a Sec., CP 78210San Luis PotosI (Mexico); Prutskij T, E-mail: fcoe_ov@prodigy.net.mx, E-mail: andre@cactus.iico.uaslp.mx [BUAP, Instituto de Ciencias, Apartado Postal 207, 72000, Puebla (Mexico)

2011-01-01

In this work we inform about quantum dots (QD) obtained by Liquid Phase Epitaxy (LPE) on GaAs substrates from under-saturated In-As liquid phases. In our processes, we have prepared saturated In-rich liquid phases by dissolving an InAs wafer at one of the temperatures interval from 450 to 414 C for 60 minutes. The contact between In-As liquid phase and the GaAs substrate was always done at a constant temperature of 444 C for 5 seconds. Thus, the growth temperature for most of the samples was higher than the liquidus temperature. We think that the growth driving force is related to a transient process that occurs when the system is trying to reach equilibrium. Under the atom force microscope (AFM) we have observed nano-islands on the surfaces of the samples obtained from under-saturated liquid phases prepared at 438, 432 and 426 C. The 25 K photoluminescence spectrum shows a peak at a 1.33 eV, in addition to the GaAs related line.

Studies on the controlled growth of InAs nanostructures on scission surfaces

International Nuclear Information System (INIS)

Bauer, J.

2006-01-01

The aim of this thesis was the controlled alignment of self-assembled InAs nano-structures on a {110}-oriented surface. The surface is prestructured with the atomic precision offered by molecular beam epitaxy, using the cleaved edge overgrowth-technique. On all samples grown within this work, the epitaxial template in the first growth step was deposited on a (001)GaAs substrate, while the InAs-layer forming the nanostructures during the second growth step was grown on cleaved {110}-GaAs surfaces. Atomic Force Microscopy (AFM) investigations demonstrate the formation of quantum dot (QD)-like nanostructures on top of the AlAs-stripes. X-ray diffraction measurements on large arrays of aligned quantum dots demonstrate that the quantum dots are formed of pure InAs. First investigations on the optical properties of these nanostructures were done using microphotoluminescence-spectroscopy with both high spatial and spectral resolution. (orig.)

Linear electro-optic coefficient in multilayer self-organized InAs quantum dot structures

NARCIS (Netherlands)

Akca, I.B.; Dana, A.; Aydinli, A.; Rossetti, M.; Li, L.; Dagli, N.; Fiore, A.

2007-01-01

The electro-optic coefficients of self-organized InAs quantum dot layers in molecular beam epitaxy grown laser structures in reverse bias have been investigated. Enhanced electrooptic coefficients compared to bulk GaAs were observed.

Non-proliferation policies and demand for uranium

International Nuclear Information System (INIS)

Warnecke, S.J.

1978-01-01

The non-proliferation policies of USA, Canada and Australia are outlined, and the effects on nuclear policy in the consumer countries, particularly the member states of the European Community and Japan are considered. Supply and demand in relation to uranium, security and economic aspects are covered. Reprocessing, the use of plutonium in breeder reactors, and the wider issues of international confidence and trade are discussed. (U.K.)

Environmental effects of additional uranium development required by a non-proliferation policy

International Nuclear Information System (INIS)

Baca, T.E.; Scudella, G.

1978-01-01

New Mexico can expect to see an accelerated development of its uranium resources. The President's policy on non-proliferation will impact the degree and quantity of uranium ore mined. Environmental impacts are significant and are affected by the mining and milling phase more than any other aspect of the uranium fuel cycle. The state has begun evaluating the resource-associated impacts of uranium mining and milling, although very little reliable data are available. The information gathered, however, shows a need for state and Federal evaluation of both the impacts and the non-proliferation policy. 4 references

Nuclear Safeguards and Non-Proliferation Education at Texas A&M University

International Nuclear Information System (INIS)

Gariazzo, C.; Charlton, W.

2015-01-01

The MS degree in Nuclear Engineering - Non-proliferation at Texas A&M University is administered by the Nuclear Security Science and Policy Institute (NSSPI). The oldest and largest of its kind in the US, 45 M.S. and 15 Ph.D. students conducted technical research in relevant areas: safeguards, nuclear security, non-proliferation, and arms control. In addition to focusing on graduate education with a wide combination of internationally-recognized talent, NSSPI faculty lead research and service activities in safeguarding of nuclear materials and reducing nuclear threats. Texas A&M Nuclear Engineering students take relevant nonproliferation and safeguards courses (within the College of Engineering and the Texas A&M Bush School of Government) as well as conduct their research under competent experts. The complete educational experience here is unique because of the strong research and educational support NSSPI provides. This paper will detail these endeavors and convey contributions from NSSPI for developing next-generation safeguards experts via practical experiences and strong affiliations with real-world practitioners. The safeguards and non-proliferation education programme blends historical, legal, technical and policy aspects that is unique for a technical university such as Texas A&M. Beyond classroom lectures, NSSPI provides opportunities for students ranging from asynchronous learning modules to practical experiences. Publicly-available self-paced, online course modules in basic and advanced safeguards education have been developed by NSSPI as supplemental nuclear education for students and professionals. By leveraging NSSPI's contacts, students participate in exchange programmes with international institutions as well as partake in experiences like engaging safeguards practitioners at nuclear fuel cycle facilities around the world, conducting experiments at internationally-renowned laboratories, and representing their communities at workshops worldwide

Positive steps toward non-proliferation

Energy Technology Data Exchange (ETDEWEB)

Greenhalgh, G.

1979-08-30

Russel W. Fox and Mason Willrich in their paper, International Custody of Plutonium Stocks: A First Step Toward an International Regime for Sensitive Nuclear Energy Activities, advocate placing excess plutonium in an international custodial facility; critical criteria governing releases are outlined so that, on one hand the owners can have high confidence that their plutonium will be returned promptly, under appropriate circumstances, and on the other hand, all the other participating and concerned countries can have confidence in the assurance that plutonium will be released only for immediate use in a defined and approved civil purpose. The Stockholm International Peace Research Institute in the 1978 issue of its Year Book, recognizes a move towards a more positive approach to the problem of nuclear proliferation. It is noted that the non-proliferation strategies of the main supply countries have largely concentrated on a two-pronged approach of technology denials with tightening of safeguards. But already, enrichment, reprocessing, and breeder reactor programs extend far beyond the five nuclear weapon states. History testifies to the limitations of a policy of technical denials. SIPRI recognizes that another way to dissuade non-nuclear weapon states from creating their own enrichment or reprocessing plants would be to establish an open market for these services, a market characterized by diversity and competition. So far, there has been no case where a country has developed nuclear explosives by diverting material from a civil power station. Development of nuclear weapons by various countries is briefly noted and areas where strengthening of the Non-Proliferation Treaty is needed are noted. (MCW)

Future technology challenges in non-proliferation

International Nuclear Information System (INIS)

Richardson, J.H.

2004-01-01

Radiation detection technologies are an important tool in the prevention of proliferation. A variety of new developments have enabled enhanced performance in terms of energy resolution, spatial resolution, predictive modeling and simulation, active interrogation, and ease of operation and deployment in the field. For example, various gamma ray imaging approaches are being explored to combine spatial resolution with background suppression in order to enhance sensitivity at reasonable standoff distances and acquisition times. New materials and approaches are being developed in order to provide adequate energy resolution in field use without the necessity for liquid nitrogen. Finally, different detectors combined into distributed networks offer promise for detection and tracking of radioactive materials. As the world moves into the 21st century, the possibility of greater reliance on nuclear energy will impose additional technical requirements to prevent proliferation. In addition to proliferation resistant reactors, a careful examination of the various possible fuel cycles from cradle to grave will provide additional technical and nonproliferation challenges in the areas of conversion, enrichment, transportation, recycling and waste disposal. Radiation detection technology and information management have a prominent role in any future global regime for nonproliferation beyond the current Advanced Protocol. This work was performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48. (author)

Nuclear non-proliferation: Global security in a rapidly changing world. Carnegie International Non-Proliferation Conference, 21 June 2004, Washington, DC, USA

International Nuclear Information System (INIS)

ElBaradei, M.

2004-01-01

This statement outlines what the IAEA and the international community has learned, what are the problems faced and the nature of the required reforms in the field of non-proliferation, security, safeguards inspection. The proposals are mostly fucued on international/collective cooperation in arms control, improvements of security and effectiveness of safeguards

Nuclear non-proliferation: Global security in a rapidly changing world. Carnegie International Non-Proliferation Conference, 21 June 2004, Washington, DC, USA

Energy Technology Data Exchange (ETDEWEB)

ElBaradei, M

2004-06-21

This statement outlines what the IAEA and the international community has learned, what are the problems faced and the nature of the required reforms in the field of non-proliferation, security, safeguards inspection. The proposals are mostly fucued on international/collective cooperation in arms control, improvements of security and effectiveness of safeguards.

The Non-Proliferation Treaty and the peaceful use of nuclear energy

International Nuclear Information System (INIS)

Wilmshurst, M.J.

1983-01-01

The author discusses the reasons of criticism and even rejection of the Non-Proliferation Treaty of 1968, dealing in particular with the alledged discriminating nature of the Treaty and with the statement that the Treaty is not apt to prevent proliferation on a vertical plane. He further discusses the motives behind the efforts of potential nuclear weapons states to get nuclear weapons. The system of worldwide and bilateral safeguards and controls covering the transfer of nuclear technologies is explained. In conclusion the author suggests to pay more attention to article IV, sub-section (2) of the Non-Proliferation Treaty as this might offer a suitable approach to restricting the dissemination of nuclear explosives. (HP) [de

The Non-Proliferation Treaty: Fifteen years after entry into force

International Nuclear Information System (INIS)

1985-01-01

The need to halt a wider spread of nuclear weapons grew out of the realization that the increase in the number of countries possessing such weapons would increase the threat to world security. As the Treaty on the Non-Proliferation of Nuclear Weapons clearly states in its preamble, the proliferation of nuclear weapons would seriously enhance the danger of nuclear war. The Treaty - also known as the non-proliferation Treaty - was concluded in 1968, at a time when there were already five nuclear-weapon Powers: the United States, the Soviet Union, the United Kingdom, France and China. This fact sheet is intended to provide background material on the Treaty, including the events that led to its conclusion, an overview of its provisions and the developments at the two previously held Review Conferences

Strengthening the nuclear nonproliferation regime: focus on the civilian nuclear fuel cycle

International Nuclear Information System (INIS)

Saltiel, David H.; Pregenzer, Arian Leigh

2005-01-01

Leaders around the world and across the ideological spectrum agree that the global nonproliferation regime is facing a serious test. The emergence of sophisticated terrorist networks, black markets in nuclear technology, and technological leaps associated with globalization have conspired to threaten one of the most successful examples of international cooperation in history. The rampant proliferation of nuclear weapons that was predicted at the start of the nuclear age has been largely held in check and the use of those weapons avoided. Nonetheless, with the thirty-fifth anniversary of the Treaty on the Nonproliferation of Nuclear Weapons (NPT), the threat of nuclear proliferation seems more serious than ever. Although experts readily concede that there exist many pathways to proliferation, the threat posed by the misuse of the civilian nuclear fuel cycle has received considerable recent attention. While the connection between nuclear energy and nonproliferation has been a topic of discussion since the dawn of the nuclear age, world events have brought the issue to the forefront once again. United States President George W. Bush and International Atomic Energy Agency (IAEA) Director General Mohammad ElBaradei are among those who have highlighted proliferation risks associated with civilian nuclear power programs and called for revitalizing the nuclear nonproliferation regime to address new threats. From the possibility of diversion or theft of nuclear material or technology, to the use of national civilian programs as a cover for weapons programs - what some have called latent proliferation - the fuel cycle appears to many to represent a glaring proliferation vulnerability. Just as recognition of these risks is not new, neither is recognition of the many positive benefits of nuclear energy. In fact, a renewed interest in exploiting these benefits has increased the urgency of addressing the risks. Global energy demand is expected to at least double by the middle of

Role of non-governmental organizations in formation of non-proliferation culture in new independent countries (NIC)

International Nuclear Information System (INIS)

Sevchik, M.

2000-01-01

Purpose of the report is demonstrate the non-governmental organizations (NGO) role in formation of non-proliferation culture in former Soviet Union. Activity of Center of Non-proliferation Problems Investigation (CNPI) of Monterey Institute of International Investigations and its collaboration with existing in Commonwealth of Independent States (CIS) non-governmental organizations is considered as example. Brief information about CNPI and reasons for it representatives opening of in Kazakhstan and in other CIS-countries, as well as cooperation of NGO in Belarus, Kazakhstan, Russia and Ukraine for creation on Central Asia zone free from nuclear weapon ia given. Some measures which could promote to formation of non-proliferation culture in region are suggested

Nonproliferation Graduate Fellowship Program, Annual Report, Class of 2012

Energy Technology Data Exchange (ETDEWEB)

McMakin, Andrea H.

2013-09-23

This 32-pp annual report/brochure describes the accomplishments of the Class of 2012 of the Nonproliferation Graduate Fellowship Program (the last class of this program), which PNNL administers for the National Nuclear Security Administration. The time period covers Sept 2011 through June 2013.

Stress evolution during growth of InAs on GaAs measured by an in-situ cantilever beam setup

Energy Technology Data Exchange (ETDEWEB)

Hu Dongzhi

2007-02-13

The influence of stress on the growth of InAs on GaAs(001) by molecular beam epitaxy (MBE) is investigated in this thesis. Film force curves were measured for InAs deposition under As-rich as well as In-rich growth conditions. The growth under As-rich conditions proceeds in the Stranski- Krastanov growth mode, meaning that quantum dots are formed after the initial growth of a wetting layer. During subsequent growth interruptions or intentional annealing at the growth temperature, the quantum dots undergo ripening. This growth mode of InAs films and the subsequent annealing behavior were studied in detail in this thesis. To understand the influence of strain on the growth mechanisms, the film force curves were analyzed and correlated to the morphological evolution of the InAs films during deposition and especially during annealing. Models were developed to fit and explain the relaxation of the film force measured during the annealing of InAs quantum dots. At temperatures lower than 470 C, quantum dots undergo standard Ostwald ripening. Different mechanisms, such as kinetic and diffusion limited, determine the ripening process. Fits of models based on these mechanisms to the film force relaxation curves, show, that although the relaxation curve for annealing at 440 C can be fitted reasonably well with all the models, the model describing ripening limited by the diffusion along dot boundaries yields a slightly better fit. The relaxation curves obtained at 455 C and 470 C can be fitted very well only with the model in which the ripening is controlled by the attachment/detachment of atoms on the dot surface. Annealing of quantum dots at temperatures higher than 500 C shows a very different behavior. Atomic force microscopy images reveal that the quantum dots ripen first and then dissolve after 450 s-600 s annealing. (orig.)

Stress evolution during growth of InAs on GaAs measured by an in-situ cantilever beam setup

International Nuclear Information System (INIS)

Hu Dongzhi

2007-01-01

The influence of stress on the growth of InAs on GaAs(001) by molecular beam epitaxy (MBE) is investigated in this thesis. Film force curves were measured for InAs deposition under As-rich as well as In-rich growth conditions. The growth under As-rich conditions proceeds in the Stranski- Krastanov growth mode, meaning that quantum dots are formed after the initial growth of a wetting layer. During subsequent growth interruptions or intentional annealing at the growth temperature, the quantum dots undergo ripening. This growth mode of InAs films and the subsequent annealing behavior were studied in detail in this thesis. To understand the influence of strain on the growth mechanisms, the film force curves were analyzed and correlated to the morphological evolution of the InAs films during deposition and especially during annealing. Models were developed to fit and explain the relaxation of the film force measured during the annealing of InAs quantum dots. At temperatures lower than 470 C, quantum dots undergo standard Ostwald ripening. Different mechanisms, such as kinetic and diffusion limited, determine the ripening process. Fits of models based on these mechanisms to the film force relaxation curves, show, that although the relaxation curve for annealing at 440 C can be fitted reasonably well with all the models, the model describing ripening limited by the diffusion along dot boundaries yields a slightly better fit. The relaxation curves obtained at 455 C and 470 C can be fitted very well only with the model in which the ripening is controlled by the attachment/detachment of atoms on the dot surface. Annealing of quantum dots at temperatures higher than 500 C shows a very different behavior. Atomic force microscopy images reveal that the quantum dots ripen first and then dissolve after 450 s-600 s annealing. (orig.)

Fabrication of GaAs/Al0.3Ga0.7As multiple quantum well nanostructures on (100) si substrate using a 1-nm InAs relief layer.

Science.gov (United States)

Oh, H J; Park, S J; Lim, J Y; Cho, N K; Song, J D; Lee, W; Lee, Y J; Myoung, J M; Choi, W J

2014-04-01

Nanometer scale thin InAs layer has been incorporated between Si (100) substrate and GaAs/Al0.3Ga0.7As multiple quantum well (MQW) nanostructure in order to reduce the defects generation during the growth of GaAs buffer layer on Si substrate. Observations based on atomic force microscopy (AFM) and transmission electron microscopy (TEM) suggest that initiation and propagation of defect at the Si/GaAs interface could be suppressed by incorporating thin (1 nm in thickness) InAs layer. Consequently, the microstructure and resulting optical properties improved as compared to the MQW structure formed directly on Si substrate without the InAs layer. It was also observed that there exists some limit to the desirable thickness of the InAs layer since the MQW structure having thicker InAs layer (4 nm-thick) showed deteriorated properties.

Upotreba začina u proizvodnji tradicionalnih sireva

OpenAIRE

Josipović, Renata; Markov, Ksenija; Frece, Jadranka; Stanzer, Damir; Cvitković, Ante; Mrvčić, Jasna

2016-01-01

Sir je visoko cijenjeni mliječni proizvod u mnogim zemljama svijeta, a posebna pažnja pridaje se tradicionalnim sirevima, koji nisu samo hrana već i dio kulture i obilježja neke zemlje. Zahvaljujući zemljopisnom položaju i klimatsko-vegetacijskoj raznolikosti Republike Hrvatske, u pojedinim regijama razvijena je proizvodnja različitih tradicionalnih sireva uz upotrebu začina. Kod proizvodnje sireva sa začinima, začini se dodaju ili u sir koji se potom oblikuje, ili se sir omata lišćem začinsk...

Finland and nuclear non-proliferation: The evolution and cultivation of a norm

International Nuclear Information System (INIS)

Dassen, L. van

1998-03-01

Finland''s entrance on the non-proliferation scene was in 1963 when President Kekkonen suggested a Nordic nuclear-weapons-free zone (NWFZ). This started a debate in and among the Nordic countries and it created a Finnish profile towards the Soviet Union. In most cases, the Soviets tried to bring Finland into a much closer relationship with the USSR. The mere prospect and debate on a Nordic NWFZ reduced the incentive for the Soviets to undermine Finnish neutrality or their desire to suggest consultations according to the Treaty of Friendship, Cooperation and Mutual Assistance on military assistance in the case of a threat to Soviet and/or Finnish security. During the negotiations on the Non-Proliferation Treaty, 1965-1968, Finland played a very active role as a bridge-builder, first between the superpowers and later between the developed and the developing world. This activity gave Finland a name in the UN, strengthened its neutrality and established good relations with the West as well. In 1978, Kekkonen brought up the Nordic NWFZ once more, this time under influence of certain strategic challenges to Finland and general East-West developments. In this Kekkonen had much backing by the public in Finland whereas other states reacted very reluctantly. Politics in Finland has to a large extent been marked by the relations with Russia and later the Soviet Union. However, nuclear non-proliferation was used to ease the weight of this imposing neighbour; a strategy that certainly must be regarded as successful. While achieving this, it was also possible to increase contacts with western states and remain accepted as a neutral state. For Finland, non-proliferation policy was initially a suitable issue to solve other problems than those related exclusively to proliferation. But it was also a policy with a high degree of persistence, pragmatism and willingness to work with concrete issues that maybe do not reach the international limelight in the short run but that work in

Finland and nuclear non-proliferation: The evolution and cultivation of a norm

Energy Technology Data Exchange (ETDEWEB)

Dassen, L. van [Uppsala Univ. (Sweden). Dept. of Peace and Conflict Research

1998-03-01

Finland``s entrance on the non-proliferation scene was in 1963 when President Kekkonen suggested a Nordic nuclear-weapons-free zone (NWFZ). This started a debate in and among the Nordic countries and it created a Finnish profile towards the Soviet Union. In most cases, the Soviets tried to bring Finland into a much closer relationship with the USSR. The mere prospect and debate on a Nordic NWFZ reduced the incentive for the Soviets to undermine Finnish neutrality or their desire to suggest consultations according to the Treaty of Friendship, Cooperation and Mutual Assistance on military assistance in the case of a threat to Soviet and/or Finnish security. During the negotiations on the Non-Proliferation Treaty, 1965-1968, Finland played a very active role as a bridge-builder, first between the superpowers and later between the developed and the developing world. This activity gave Finland a name in the UN, strengthened its neutrality and established good relations with the West as well. In 1978, Kekkonen brought up the Nordic NWFZ once more, this time under influence of certain strategic challenges to Finland and general East-West developments. In this Kekkonen had much backing by the public in Finland whereas other states reacted very reluctantly. Politics in Finland has to a large extent been marked by the relations with Russia and later the Soviet Union. However, nuclear non-proliferation was used to ease the weight of this imposing neighbour; a strategy that certainly must be regarded as successful. While achieving this, it was also possible to increase contacts with western states and remain accepted as a neutral state. For Finland, non-proliferation policy was initially a suitable issue to solve other problems than those related exclusively to proliferation. But it was also a policy with a high degree of persistence, pragmatism and willingness to work with concrete issues that maybe do not reach the international limelight in the short run but that work in

Effects of crossed states on photoluminescence excitation spectroscopy of InAs quantum dots

Directory of Open Access Journals (Sweden)

Lin Chien-Hung

2011-01-01

Full Text Available Abstract In this report, the influence of the intrinsic transitions between bound-to-delocalized states (crossed states or quasicontinuous density of electron-hole states on photoluminescence excitation (PLE spectra of InAs quantum dots (QDs was investigated. The InAs QDs were different in size, shape, and number of bound states. Results from the PLE spectroscopy at low temperature and under a high magnetic field (up to 14 T were compared. Our findings show that the profile of the PLE resonances associated with the bound transitions disintegrated and broadened. This was attributed to the coupling of the localized QD excited states to the crossed states and scattering of longitudinal acoustical (LA phonons. The degree of spectral linewidth broadening was larger for the excited state in smaller QDs because of the higher crossed joint density of states and scattering rate.

X-ray characterization Si-doped InAs nanowires grown on GaAs

Energy Technology Data Exchange (ETDEWEB)

Saqib, Muhammad; Biermanns, Andreas; Pietsch, Ullrich [Universitaet Siegen, Festkoerperphysik (Germany); Grap, Thomas; Lepsa, Mihail [Forschungszentrum Juelich, Institut fuer Bio- und Nanosysteme (Germany)

2011-07-01

Semiconductor nanowires (NW) are of particular interest due to the ability to synthesize single-crystalline 1D epitaxial structures and heterostructures in the nanometer range. However, many details of the growth mechanism are not well understood. In particular, understanding and control of doping mechanisms during NW growth are important issues for technological applications. In this contribution we present a x-ray diffraction study of the influence of Si-doping in InAs NWs grown on GaAs(111) substrates using In-assisted MBE growth. With the help of coplanar and asymmetric x-ray diffraction, we monitor the evolution of the lattice constants and structure of the InAs NWs as function of doping concentration. We observe that increasing the nominal doping concentration leads to the appearance of additional diffraction maxima corresponding to material whose vertical lattice parameter is 1% smaller than that of the undoped nanowires. Those lattice parameters can be attributed with alloy formation in the form of island like crystallites.

Brazil and Mexico in the Nonproliferation Regime, Common Structures and Divergent Trajectories in Latin America

OpenAIRE

Sotomayor, Arturo C.

2014-01-01

Chapter 8 There are multiple options Latin American countries to support and comply with the nuclear nonproliferation regime. At the global level, states can decide to ratify the core treaties and join their supporting institutions such as the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), the International Atomic Energy Agency (IAEA), the Comprehensive Nuclear-Test-Ban Treaty (CTBT), the Nuclear Suppliers Group (NSG), the Missile Technology Control Regime, the...

Nuclear safety and control act, chapter 9: An Act to establish the Canadian Nuclear Safety Commission and to make consequential amendements to other Acts

International Nuclear Information System (INIS)

1997-01-01

The purpose of this Act is to provide for: the limitation, to a reasonable level and in a manner that is consistent with Canada's international obligations, of the risks to national security, the health and safety of persons and the environment that are associated with the development, production and use of nuclear energy and the production, possession and use of nuclear substances, prescribed equipment and prescribed information; and the implementation in Canada of measures to which Canada has agreed respecting international control of the development, production and use of nuclear energy, including the non-proliferation of nuclear weapons and nuclear explosive devices

Report of “the 2013 international forum on peaceful use of nuclear energy, nuclear non-proliferation and nuclear security. Ensuring nuclear non-proliferation and nuclear security of nuclear fuel cycle options in consideration of the accident at TEPCO's Fukushima Daiichi Nuclear Power Station”

International Nuclear Information System (INIS)

Yamamura, Tsukasa; Suda, Kazunori; Tomikawa, Hirofumi; Suzuki, Mitsutoshi; Kuno, Yusuke; Mochiji, Toshiro

2014-03-01

The Japan Atomic Energy Agency (JAEA) held “International Forum on Peaceful Use of Nuclear Energy, Nuclear Non-proliferation and Nuclear Security – Ensuring Nuclear Non-Proliferation and Nuclear Security of Nuclear Fuel Cycle Options in consideration of the Accident at TEPCO's Fukushima Daiichi Nuclear Power Station –” on 3 and 4 December 2013, with the Japan Institute of International Affairs (JIIA) and School of Engineering, The University of Tokyo, as co-hosts. In the Forum, officials from Japan, the United States, France and International Atomic Energy Agency (IAEA) explained their efforts regarding peaceful use of nuclear energy and nuclear non-proliferation. Discussion was made in two panels, entitled “Nuclear non-proliferation and nuclear security measures of nuclear fuel cycle options in consideration of the Accident at TEPCO's Fukushima Daiichi Nuclear Power Station” and “Roles of safeguards and technical measures for ensuring nuclear non-proliferation for nuclear fuel cycle options”. In the first panel based on the implications of the Accident at TEPCO's Fukushima Daiichi Nuclear Power Station on the domestic and global nuclear energy use and increased interest in the back end of nuclear fuel cycle, discussion was made on nuclear non-proliferation and nuclear security challenges on both fuel cycle options from the policy and institutional viewpoints whereas in the second panel the roles of safeguards and proliferation resistant nuclear technology including plutonium burning technology in ensuring nuclear non-proliferation and nuclear security in the back end of nuclear fuel cycle were discussed. Officials and experts from Japan, IAEA, the United States, France and Republic of Korea participated in the panel and made contributions to active discussion. This report includes abstracts of keynote speeches, summaries of two panel discussions and materials of the presentations in the forum. The editors take full responsibility for the wording

Molecular dynamics growth modeling of InAs1-xSbx-based type-II superlattice

Science.gov (United States)

Ciani, Anthony J.; Grein, Christoph H.; Irick, Barry; Miao, Maosheng; Kioussis, Nicholas

2017-09-01

Type-II strained-layer superlattices (T2SL) based on InAs1-xSbx are a promising photovoltaic detector material technology for thermal imaging; however, Shockley-Read-Hall recombination and generation rates are still too high for thermal imagers based on InAs1-xSbx T2SL to reach their ideal performance. Molecular dynamics simulations using the Stillinger-Weber (SW) empirical potentials are a useful tool to study the growth of tetrahedral coordinated crystals and the nonequilibrium formation of defects within them, including the long-range effects of strain. SW potentials for the possible atomic interactions among {Ga, In, As, Sb} were developed by fitting to ab initio calculations of elastically distorted zinc blende and diamond unit cells. The SW potentials were tested against experimental observations of molecular beam epitaxial (MBE) growth and then used to simulate the MBE growth of InAs/InAs0.5Sb0.5 T2SL on GaSb substrates over a range of processes parameters. The simulations showed and helped to explain Sb cross-incorporation into the InAs T2SL layers, Sb segregation within the InAsSb layers, and identified medium-range defect clusters involving interstitials and their induction of interstitial-vacancy pairs. Defect formation was also found to be affected by growth temperature and flux stoichiometry.

Increasing the quantum efficiency of GaAs solar cells by embedding InAs quantum dots

Science.gov (United States)

Salii, R. A.; Mintairov, S. A.; Nadtochiy, A. M.; Payusov, A. S.; Brunkov, P. N.; Shvarts, M. Z.; Kalyuzhnyy, N. A.

2016-11-01

Development of Metalorganic Vapor Phase Epitaxy (MOVPE) technology of InAs quantum dots (QDs) in GaAs for photovoltaic applications is presented. The growth peculiarities in InAs-GaAs lattice-mismatched system were considered. The photoluminescence (PL) intensity dependences on different growth parameters were obtained. The multimodal distribution of QDs by sizes was found using AFM and PL methods. GaAs solar cell nanoheterostructures with imbedded QD arrays were designed and obtained. Ones have been demonstrated a significant increase of quantum efficiency and photogenerated current of QD solar cells due to photo effect in InAs QD array (0.59 mA/cm2 for AM1.5D and 82 mA/cm2 for AM0).

Temperature dependence of the transport properties of spin field-effect transistors built with InAs and Si channels

Science.gov (United States)

Osintsev, D.; Sverdlov, V.; Stanojević, Z.; Makarov, A.; Selberherr, S.

2012-05-01

We study the transport properties of the Datta-Das spin field-effect transistor built on InAs and Si. First, we demonstrate that the amplitude of the magnetoresistance oscillations as a function of the band mismatch between the ferromagnetic contacts and the semiconductor channel made of InAs decreases dramatically with increasing temperature. A shorter InAs channel is needed to create an InAs-based SpinFET which will operate at higher temperatures. Second, we show that the [1 0 0] orientation of the fin is preferable for silicon SpinFETs due to stronger modulation of the conductance as a function of spin-orbit interaction and magnetic field. Short silicon fins can be used for current modulation as a function of the conduction band mismatch between the channel and the ferromagnetic contacts only at relatively low temperatures. In contrast, longer silicon channels allow a TMR modulation at room temperature by changing the strength of the spin-orbit interaction through the gate bias.

Temperature effect on the growth of Au-free InAs and InAs/GaSb heterostructure nanowires on Si substrate by MOCVD

Science.gov (United States)

Kakkerla, Ramesh Kumar; Anandan, Deepak; Hsiao, Chih-Jen; Yu, Hung Wei; Singh, Sankalp Kumar; Chang, Edward Yi

2018-05-01

We demonstrate the growth of vertically aligned Au-free InAs and InAs/GaSb heterostructure nanowires on Si (1 1 1) substrate by Metal Organic Chemical Vapor Deposition (MOCVD). The effect of growth temperature on the morphology and growth rate of the InAs and InAs/GaSb heterostructure nanowires (NWs) is investigated. Control over diameter and length of the InAs NWs and the GaSb shell thickness was achieved by using growth temperature. As the GaSb growth temperature increase, GaSb radial growth rate increases due to the increase in alkyl decomposition at the substrate surface. Diffusivity of the adatoms increases as the GaSb growth temperature increase which results in tapered GaSb shell growth. Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) measurements revealed that the morphology and shell thickness can be tuned by the growth temperature. Electron microscopy also shows the formation of GaSb both in radial and axial directions outside the InAs NW core can be controlled by the growth temperature. This study demonstrates the control over InAs NWs growth and the GaSb shell thickness can be achieved through proper growth temperature control, such technique is essential for the growth of nanowire for future nano electronic devices, such as Tunnel FET.

NNSA Nonproliferation Graduate Fellowship Program Annual Report June 2008 - May 2009

Energy Technology Data Exchange (ETDEWEB)

Berkman, Clarissa O.; Fankhauser, Jana G.

2010-03-01

In 2009, the Nonproliferation Graduate Fellowship Program (NGFP) completed its 16th successful year in support of the NNSA’s mission by developing future leaders in nonproliferation and promoting awareness of career opportunities. We provide this annual report to review program activities from June 2008 through May 2009 - the fellowship term for the Class of 2008. Contents include: Welcome Letter Introduction The NGFP Team Program Management Highlights Class of 2008 Incoming Fellows Orientation Travel Career Development Management of the Fellows Performance Highlights Closing Ceremony Encore Performance Where They Are Now Alumnus Career Highlights: Christine Buzzard Class of 2009 Applicant Database Upgrades Fall Recruitment Activities Interviews Hiring and Clearances Introducing the Class of 2009 Class of 2010 Recruitment Strategy On the Horizon Appendix A: Class of 2009 Fellows

Cathodoluminescence imaging and spectroscopy of excited states in InAs self-assembled quantum dots

International Nuclear Information System (INIS)

Khatsevich, S.; Rich, D.H.; Kim, Eui-Tae; Madhukar, A.

2005-01-01

We have examined state filling and thermal activation of carriers in buried InAs self-assembled quantum dots (SAQDs) with excitation-dependent cathodoluminescence (CL) imaging and spectroscopy. The InAs SAQDs were formed during molecular-beam epitaxial growth of InAs on undoped planar GaAs (001). The intensities of the ground- and excited-state transitions were analyzed as a function of temperature and excitation density to study the thermal activation and reemission of carriers. The thermal activation energies associated with the thermal quenching of the luminescence were measured for ground- and excited-state transitions of the SAQDs, as a function of excitation density. By comparing these activation energies with the ground- and excited-state transition energies, we have considered various processes that describe the reemission of carriers. Thermal quenching of the intensity of the QD ground- and first excited-state transitions at low excitations in the ∼230-300-K temperature range is attributed to dissociation of excitons from the QD states into the InAs wetting layer. At high excitations, much lower activation energies of the ground and excited states are obtained, suggesting that thermal reemission of single holes from QD states into the GaAs matrix is responsible for the observed temperature dependence of the QD luminescence in the ∼230-300-K temperature range. The dependence of the CL intensity of the ground-and first excited-state transition on excitation density was shown to be linear at all temperatures at low-excitation density. This result can be understood by considering that carriers escape and are recaptured as excitons or correlated electron-hole pairs. At sufficiently high excitations, state-filling and spatial smearing effects are observed together with a sublinear dependence of the CL intensity on excitation. Successive filling of the ground and excited states in adjacent groups of QDs that possess different size distributions is assumed to

Optical characterization of InAs quantum wells and dots grown radially on wurtzite InP nanowires

International Nuclear Information System (INIS)

Lindgren, David; Kawaguchi, Kenichi; Heurlin, Magnus; Borgström, Magnus T; Pistol, Mats-Erik; Samuelson, Lars; Gustafsson, Anders

2013-01-01

Correlated micro-photoluminescence (μPL) and cathodoluminescence (CL) measurements are reported for single core–shell InP–InAs wurtzite nanowires grown using metal–organic vapor phase epitaxy. Samples covering a radial InAs shell thickness of 1–12 ML were investigated. The effective masses for the wurtzite material were determined from the transition energy dependence of the InAs shell thickness, using a model based on linear deformation potential theory. InP cores with segments of mixed zincblende and wurtzite, on which quantum dots nucleated selectively, were also investigated. Narrow peaks were observed by μPL and the spatial origin of the emission was identified with CL imaging. (paper)

STM/STS Measurements of Two-Dimensional Electronic States in Magnetic Fields at Epitaxially Grown InAs(111)A Surfaces

International Nuclear Information System (INIS)

Niimi, Y; Kanisawa, K; Kojima, H; Kambara, H; Hirayama, Y; Tarucha, S; Fukuyama, Hiroshi

2007-01-01

The local density of states (LDOS) at the epitaxially grown InAs surface on a GaAs substrate was studied at very low temperatures in magnetic fields up to 6 T by scanning tunneling microscopy and spectroscopy. We observed a series of peaks, associated with Landau quantization of the two-dimensional electron system (2DES), in the tunnel spectra just above the subband energy (-80 meV) of the 2DES. The intervals between the peaks are consistent with the estimation from the effective mass of the 2DES at the InAs surface. In a wider energy range, another type of oscillation which was independent of magnetic field was also observed. This oscillation can be explained by the energy dependence of the transmission probability of the tunneling current through the Schottky barrier formed at the interface between the InAs film and GaAs substrate

Energy Band Structure Studies Of Zinc-Blende GaAs and InAs ...

African Journals Online (AJOL)

A self-consistent calculation of the structural and electronic properties of zinc blende GaAs and InAs has been carried out. The calculations were done using the full potential-linearized augmented plane wave (FPLAPW) method within the density functional theory (DFT). The exchange-correlation energy used is the ...

Nonproliferation analysis of the reduction of excess separated plutonium and high-enriched uranium

International Nuclear Information System (INIS)

Persiani, P.J.

1995-01-01

The purpose of this preliminary investigation is to explore alternatives and strategies aimed at the gradual reduction of the excess inventories of separated plutonium and high-enriched uranium (HEU) in the civilian nuclear power industry. The study attempts to establish a technical and economic basis to assist in the formation of alternative approaches consistent with nonproliferation and safeguards concerns. The analysis addresses several options in reducing the excess separated plutonium and HEU, and the consequences on nonproliferation and safeguards policy assessments resulting from the interacting synergistic effects between fuel cycle processes and isotopic signatures of nuclear materials

Nonproliferation impacts assessment for the management of the Savannah River Site aluminum-based spent nuclear fuel

International Nuclear Information System (INIS)

1998-12-01

On May 13, 1996, the US established a new, 10-year policy to accept and manage foreign research reactor spent nuclear fuel containing uranium enriched in the US. The goal of this policy is to reduce civilian commerce in weapons-usable highly enriched uranium (HEU), thereby reducing the risk of nuclear weapons proliferation. Two key disposition options under consideration for managing this fuel include conventional reprocessing and new treatment and packaging technologies. The Record of Decision specified that, while evaluating the reprocessing option, ''DOE will commission or conduct an independent study of the nonproliferation and other (e.g., cost and timing) implications of chemical separation of spent nuclear fuel from foreign research reactors.'' DOE's Office of Arms Control and Nonproliferation conducted this study consistent with the aforementioned Record of Decision. This report addresses the nonproliferation implications of the technologies under consideration for managing aluminum-based spent nuclear fuel at the Savannah River Site. Because the same technology options are being considered for the foreign research reactor and the other aluminum-based spent nuclear fuels discussed in Section ES.1, this report addresses the nonproliferation implications of managing all the Savannah River Site aluminum-based spent nuclear fuel, not just the foreign research reactor spent nuclear fuel. The combination of the environmental impact information contained in the draft EIS, public comment in response to the draft EIS, and the nonproliferation information contained in this report will enable the Department to make a sound decision regarding how to manage all aluminum-based spent nuclear fuel at the Savannah River Site

Intermediate band solar cell simulation use InAs quantum dot in GaAs

International Nuclear Information System (INIS)

Hendra P, I. B.; Rahayu, F.; Sahdan, M. F.; Darma, Y.

2015-01-01

Intermediate band solar cell (IBSC) has become a new approach in increasing solar cell efficiency significantly. One way to create intermediate band is by proposing quantum dots (QD) technology. One of the important aspects in utilizing IBSC is the absorption of light. In this work we simulated the influence of QD arrangement in order to increase absorption coefficient and solar cell efficiency. We also simulated the influence of QD size to capture a wider light spectrum. We present a simple calculation method with low computing power demand. Results show that the increasing in quantum dot size can increase in capturing wider spectrum of light. Arrangement InAs QD in bulk material GaAs can capture wider spectrum of light and increase the absorption coefficient. The arrangement InAs QD 2 nm in GaAs bulk can increase solar cell efficiency up to 49.68%

The photoluminescence decay time of self-assembled InAs quantum dots covered by InGaAs layers

International Nuclear Information System (INIS)

Shu, G W; Wang, C K; Wang, J S; Shen, J L; Hsiao, R S; Chou, W C; Chen, J F; Lin, T Y; Ko, C H; Lai, C M

2006-01-01

The temperature dependence of the time-resolved photoluminescence (PL) of self-assembled InAs quantum dots (QDs) with InGaAs covering layers was investigated. The PL decay time increases with temperature from 50 to 170 K, and then decreases as the temperature increases further above 170 K. A model based on the phonon-assisted transition between the QD ground state and the continuum state is used to explain the temperature dependence of the PL decay time. This result suggests that the continuum states are important in the carrier capture in self-assembled InAs QDs

Time-resolved x-ray diffraction measurements of high-density InAs quantum dots on Sb/GaAs layers and the suppression of coalescence by Sb-irradiated growth interruption

International Nuclear Information System (INIS)

Kakuda, Naoki; Yamaguchi, Koichi; Kaizu, Toshiyuki; Takahasi, Masamitu; Fujikawa, Seiji

2010-01-01

Self-assembly of high-density InAs quantum dots (QDs) on Sb-irradiated GaAs buffer layers was observed in-situ by a time-resolved X-ray diffraction (XRD) technique using a combination of XRD and molecular beam epitaxy. Evolution of dot height and lattice constant was analyzed during InAs QD growth and subsequent growth interruption (GI), and as a result, dislocated giant dots due to coalescence and coherent dots were separately evaluated. An Sb-irradiated GI (Sb-GI) method to be applied after InAs growth was attempted for the suppression of coalescence. Using this method, the XRD intensity of giant dots decreased, and the photoluminescence intensity of InAs QDs was enhanced. High-density InAs QDs without giant dots were produced by using the combination of the QD growth on the Sb-irradiated GaAs buffer layers and the Sb-GI. (author)

Fast reactors and nonproliferation

International Nuclear Information System (INIS)

Orlov, V.V.

1997-01-01

1.Three aspects of nonproliferation relevant to nuclear power are: Pu buildup in NPP spent fuel cooling ponds (∼ 104 t in case of consumption of ∼ 107 t cheap uranium). Danger of illegal radiochemical extraction of Pu for weapons production; Pu extraction from NPP fuel at the plants available in nuclear countries, its burning along with weapon-grade Pu in NPP reactors or in special-purpose burners; increased hazard of nuclear weapons sprawl with breeders and closed fuel cycle technology spreading all over the world. 2.The latter is one of major obstacles to creation of large-scale nuclear power. 3.Nuclear power of the first stage using 235 U will be able to meet the demands of certain fuel-deficient countries and regions, replacing ∼ 5-10% of conventional fuels in the global consumption for a number of decades. 4.Fast reactors of the first generation and the currently employed fuel technology are far from exhausting their potential for solving economic problems and meeting the challenges of safety, radioactive waste and nonproliferation. Development of large-scale nuclear power will become an option accepted by society for solving energy problems in the following century, provided a breeder technology is elaborated and demonstrated in the next 15-20 years, which would comply with the totality of the following requirement: full internal Pu breeding deterministic elimination of severe accidents involving fuel damage and high radioactivity releases: fast runaway, loss of coolant, fires, steam and hydrogen explosions, etc.; reaching a balance between radioactive wastes disposed of and uranium mined in terms of radiation hazard; technology of closed fuel cycle preventing its use for Pu extraction and permitting physical protection from fuel thefts;economic competitiveness of nuclear power for most of countries and regions, i.e. primarily the cost of NPPs with fat reactors is to be below the cost of modern LWR plants, etc

Nuclear disarmament. Options for the coming non-proliferation treaty surveillance cycle; Nukleare Abruestung. Optionen fuer den kommenden Ueberpruefungszyklus des NVV

Energy Technology Data Exchange (ETDEWEB)

Mueller, Harald

2011-07-01

The report is aimed on the nuclear disarmament discussion with respect to the disagreement of nuclear weapon states and those without nuclear weapons, esp. the non-aligned movement (NAM) concerning the non-proliferation treaty. The report covers the following issues: The role of the non-proliferation treaty, nuclear disarmament in the last surveillance conference 2010, the different disarmament philosophies, the possibilities of bridging the disagreement, further disarmament options for the future non-proliferation treaty surveillance cycle, German options for the future surveillance cycle.

Policy of Kyrgyz Republic in the field of weapons of mass destruction nonproliferation

International Nuclear Information System (INIS)

Duisheeva, Zh.Z.

2010-01-01

Full text: Kyrgyz Republic is principle and sequential member of accepting effective international measures, directed to active prevention to weapons of mass destruction (WMD) proliferation, its components and means of delivery. Commitment to prevention policy and WMD nonproliferation is one of basic principles of foreign and domestic policy of Kyrgyz Republic. The real measure against WMD proliferation and relating to its production technologies of military, special and dual use is international export control based on national systems of export control including smoothly running national system of account for, control and physical protection of arm materials. Currently juridical basis of export control system in Kyrgyz Republic is actively developing. In 2003 the Law of Kyrgyz Republic On export control, based on principles and norms of international law in the field of export control was adopted. The Law On export control determines basic principles of state policy, legal activity basis of state management and participants of foreign-economic activity in the field of export control, as well as defines their rights, obligations and responsibilities in this field. Also in the law, the requirements of international treaties realization in the field of WMD nonproliferation and means of their delivery, signed by Kyrgyzstan, is defined as one of national systems goals of export control. In article 13, Law On export control it is defined that international cooperation in the field of export control by means of efforts coordination and cooperation with foreign states on prevention of WMD nonproliferation, means of their delivery and technologies on their creation; participation in international regimes of export control and international forums, as well as carrying out negotiations, consultations with foreign states, bilateral information exchange and realization of joint programs and other events in the field of export control on bilateral and multilateral basis. By

Nuclear proliferation and civilian nuclear power: report of the Nonproliferation Alternative Systems Assessment Program. Volume VII. International perspectives

International Nuclear Information System (INIS)

1979-12-01

The purpose of this volume is to assess the proliferation vulnerabilities of the present deployment of civilian nuclear-power systems within the current nonproliferation regime and, in light of their prospective deployment, to consider technical and institutional measures and alternatives which may contribute to an improved regime in which nuclear power could play a significant part. An assessment of these measures must include consideration of their nonproliferation effectiveness as well as their bearing upon energy security, and their operational, economic, and political implications. The nature of these considerations can provide some measure of their likely acceptability to various nations. While any final assessment of such measures and alternatives would have to examine the circumstances particular to each nation, it is hoped that the more generic assessments conducted here will be useful in suggesting guidelines for developing an improved nonproliferation regime which also helps to meet nuclear-energy needs. One chapter outlines the existing nonproliferation regime, including the Treaty for the Non-Proliferation of Nuclear Weapons (NPT), International Atomic Energy Agency (IAEA) safeguards, bilateral and multilateral requirements for agreements of cooperation and transfers of technology, and existing provisons for sanctions for violation of nonproliferation commitments. The chapter then proceeds to an assessment of various alternatives for providing assurance of fuel supply in light of this current regime. Another chapter examines a set of technical and institutional measures and alternatives for various components of once-through and closed fuel cycles. The components of the once-through fuel cycle assessed are enrichment services and spent-fuel management; the components of closed fuel cycles assessed are reprocessing and plutonium management and fast-breeder reactor (FBR) deployment

Non-proliferation of nuclear weapons: The road ahead. London, 15 January 2001

International Nuclear Information System (INIS)

ElBaradei, M.

2001-01-01

The document reproduces the text of the conference given by the Director General of the IAEA at the Royal Institute of International Affairs in London, 15 January 2001. The Director General points out that for over five decades since the summer of 1945, strategies of national and international security have been intertwined with the concept of nuclear weapons as a strategic deterrent. In his view, the achievement of a nuclear weapon free world will crucially depend on a fundamental change in that concept of 'security'. Besides the historical perspectives the paper focuses on the non-proliferation and nuclear disarmament strategies. The Director General also states that to achieve the main goal of universal non-proliferation and disarmament it is indispensable to re-evaluate nuclear weapon states status; challenge the doctrine of nuclear deterrence; develop alternatives to nuclear deterrence; and engage in constructive dialogue. In conclusion it is re-emphasized that there remain both the difficulties and the opportunities of the road towards nuclear disarmament. It is pointed out that construction of a non-proliferation regime with near-universal participation has been successful and some progress towards nuclear disarmament has been achieved, but several goals must be pursued to maintain and build upon achievements

Report on the 8. ESARDA course on nuclear safeguards and non-proliferation

International Nuclear Information System (INIS)

Grape, S.; Jonter, T.

2013-01-01

The 8. ESARDA course on nuclear safeguards and non-proliferation took place in Uppsala, Sweden, on September 12-16, 2011. 44 participants from 15 countries followed the one week long course, comprising four days of lectures, one group exercise and one full day visit to the Swedish final repository (SFR) for short-lived radioactive waste. The lectures covered political and technical aspects related to the general background of safeguards legislation and treaties, the nuclear fuel cycle, destructive and non-destructive safeguards techniques, physical protection, verification technologies such as nuclear material accountancy and control, safeguards inspections, remote monitoring, containment and surveillance, export control, illicit trafficking and nuclear forensics. The course also contained a group exercise, whereby the participants learnt about different nonproliferation treaties on/or related to Weapons of Mass Destruction (WMD): the Chemical Weapons Convention (CWC), the Biological and Toxin Weapons Convention (BWC), the nuclear Non-Proliferation Treaty (NPT) as well as the Comprehensive Nuclear Test Ban Treaty (CTBT) and the Fissile Material Cut-off Treaty (FMCT). The task of the group exercise was to discuss and compare the treaties with respect to obligations and rights of state parties, verification of compliance, membership, terrorism, similarities/differences, successes and failures. The paper is followed by the slides of the presentation

Australian Safeguards and Non-Proliferation Office, Annual Report 2001-2002

International Nuclear Information System (INIS)

2002-01-01

During the year Australian Safeguards and Non-Proliferation Office (ASNO) continued our substantial contribution to the development and strengthening of international verification regimes concerned with weapons of mass destruction (WMD). Domestically, ASNO conducted, or contributed to, review of WMD- related legislation and administration, amending permits to enhance security arrangements, and beginning development of supporting legislative changes. Another major area of work is the replacement research reactor project, where ASNO has been closely involved through safeguards and security aspects. This year has been dominated by the terrorist attacks of 11 September 2001 on the United States, and ongoing consequences. These events, and the concern that terrorists would use WMD if they were able to acquire them, have served to emphasise the importance of effective counter-proliferation and counter-terrorism measures to complement the non-proliferation regimes. They have also focused attention on the need to deal with non- compliance with WMD treaty commitments. The key achivements reported for the year under review include: 1. All treaty and statutory requirements met in respect of: nuclear material and nuclear items in Australia, Australian uranium exports (Australian Obligated Nuclear Material), chemicals covered by the CWC (Chemical Weapons Convention) and establishment of CTBT(Comprehensive Nuclear-Test-Ban Treaty) monitoring stations; 2. Effective contribution to strengthening non-proliferation verification regimes and counter terrorism initiatives: ongoing support for IAEA safeguards development, regional outreach on IAEA safeguards, CWC implementation and encouraging CTBT ratification, ANSTO security upgraded; security plan approved for construction of replacement research reactor, review, with other responsible authorities, of security of CWC related chemicals, and radiation sources

Nonlinear refraction at the absorption edge in InAs.

Science.gov (United States)

Poole, C D; Garmire, E

1984-08-01

The results of measurements of nonlinear refraction at the absorption edge in InAs between 68 and 90 K taken with an HF laser are compared with those of a band-gap resonant model in which the contribution of the light-hole band is included and found to account for more than 40% of the observed nonlinear refraction. A generalized expression for the nonlinear index is derived by using the complete Fermi-Dirac distribution function. Good agreement between theory and experiment is obtained, with no free parameters.

Quantification of Discrete Oxide and Sulfur Layers on Sulfur-Passivated InAs by XPS

National Research Council Canada - National Science Library

Petrovykh, D. Y; Sullivan, J. M; Whitman, L. J

2005-01-01

.... The S-passivated InAs(001) surface can be modeled as a sulfur-indium-arsenic layer-cake structure, such that characterization requires quantification of both arsenic oxide and sulfur layers that are at most a few monolayers thick...

Non-proliferation and the control of atomic energy

International Nuclear Information System (INIS)

Goldschmidt, B.

1977-01-01

The non-proliferation problem has never ceased to haunt and to influence those responsible for the development of atomic energy. During and after the Second World War, Anglo-American co-operation was reflected in restrictions on the exchange of enrichment and reprocessing know-how. Between 1945 and 1955, the Anglo-Saxon powers continued with the policy of secrecy and uranium monopoly decided on in 1943 at the Quebec summit conference. Starting in 1955, the failure of this policy led - at the suggestion of the United States of America - to a freer flow of information and to the creation of the International Atomic Energy Agency with its safeguards, which permitted widespread application of the policy of technical assistance subject to controls and widespread commerce in research and power reactors - mainly fuelled with enriched uranium and manufactured in the USA. There followed periods characterized by general legal blocks, with two unilateral renunciation treaties - the Partial Test Ban Treaty of 1963, covering non-underground tests, and the Treaty on the Non-Proliferation of Nuclear Weapons, of 1968, covering nuclear explosive devices and the entire fuel cycle. The Indian atomic explosion and the acceleration of nuclear programmes owing to the oil crisis prompted - in 1974 - efforts by supplier countries to limit the transfer of sensitive technology and the possession of plants capable of producing substances which could be used in the production of nuclear weapons; the USA has even proposed the curtailment of plutonium extraction and of breeder construction, although these are considered by many countries to be essential to the independence of their energy development programmes. This policy of reserving the sensitive stages of the fuel cycles to a few advanced countries and the questioning of existing nuclear agreements have created, in the relations between supplier and recipient countries, a regrettable intensification of the distrust which must be dispelled

Non-proliferation and safeguards aspects. Key issue paper no. 5

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-06-01

This paper examines the current nuclear non-proliferation regime (Section 2) and the issues most likely to arise as the civil nuclear fuel cycle develops over the next 50 years (Section 3). Section 4 deals with fuel cycles and nuclear material inventories. 14 refs.

Considerations on nonproliferation regime meeting in a changing world

International Nuclear Information System (INIS)

Kurihara, Hiroyoshi; Kikuchi, Masahiro

1994-01-01

This paper summarizes the past history of worldwide nonproliferation regime, then proposes the future improvements on the regime. Present worldwide nonproliferation regime have been formulated during the cold war era. Therefore, the structure and measures of the regime were heavily influenced by the features of cold war era. Though the cold war was over, still new international order does not seem to be on the horizon, we need to review the present regime and to improve the regime compatible to new world situation. Generally speaking, the nonproliferation regime have gained moderate success so far. We could point out the following features as a kind of success: 1) No increase of overt Nuclear Weapon State (NWS), 2) All five NWSs have finally participated to the NPT, 3) South Africa has destroyed its nuclear weapons and became Non-Nuclear Weapon State (NNWS), 4) Successful conclusions of some regional arrangements, such as Tlatelolco, Ralotonga, and 5) Strengthening of export control on sensitive items. On the other hand, we recognize the following points as the failures of the regime. 6) India, Pakistan and Israel reject to join the NPT, 7) Existence of some violation against NPT regime, i.e. Iraqi case and DPRK case, 8) Insufficient effective measures against brain drain problem, 9) Risk exists for the long term extension of NPT, and 10) Insufficient flexibility to meet changing boundary conditions. We would propose the various measures for strengthening to meet changing boundary conditions, as follows: 11) Measures to be taken along with future civil use of Plutonium, 12) Strengthening and rationalizing international safeguards, 13) Countermeasures for emerging new types of nuclear proliferation, 14) Strengthening nuclear material control in NWS, 15) Measures to be taken for nuclear material from dismantled nuclear weapons, and 16) Nuclear disarmament. (author)

High tunability and superluminescence in InAs mid-infrared light emitting diodes

International Nuclear Information System (INIS)

Sherstnev, V.V.; Krier, A.; Hill, G.

2002-01-01

We report on the observation of super luminescence and high spectral current tunability (181 nm) of InAs light emitting diodes operating at 3.0 μm. The source is based on an optical whispering gallery mode which is generated near the edges of the mesa and which is responsible for the superluminescence. (author)

Statement at Inauguration Ceremony for Vienna Center for Disarmament and Non-Proliferation, 25 February 2011, Vienna, Austria

International Nuclear Information System (INIS)

Amano, Y.

2011-01-01

I was a member of the Group of Governmental Experts which drafted the United Nations Study on Disarmament and Non proliferation Education in 2002. In my new role at the IAEA, I continue to attach great importance to education. I believe it is vital that we educate the people of the world about how devastating nuclear weapons are and build awareness of the importance of nuclear disarmament and non-proliferation. I have no doubt that the new Vienna Center for Disarmament and Non-Proliferation will make an important contribution in this area. The recent conclusion of the new START Treaty between the Russian Federation and the United States was a welcome development in the nuclear disarmament field. Reducing the role and numbers of nuclear weapons is a positive step towards a safe and peaceful world free of nuclear weapons which can impact positively on nuclear non-proliferation efforts. But, of course, further steps are needed. Disarmament and non-proliferation education have an essential role to play in maintaining and strengthening the momentum towards achieving a world free of nuclear weapons. The IAEA has for decades been actively involved in promoting nuclear non-proliferation education. My colleagues and I speak about nuclear non-proliferation throughout the world. We organize briefings here in Vienna for members of parliament, government officials, think tanks, academics and other groups. We host educational seminars for NGOs, diplomats and journalists on the Agency's non-proliferation activities - the latest one was held this week. The IAEA also provides opportunities for on-the-job training and work experience to students and young professionals. Indeed, several Monterey Institute graduates are currently working with us. This is an excellent example of how disarmament and non-proliferation education can contribute to promoting international peace and security. The 9/11 terrorist attacks in the United States took place during my time with Monterey in

IAEA safeguards and non-proliferation

International Nuclear Information System (INIS)

Harry, R.J.S.

1995-02-01

An overview is given of the efforts to contain the nuclear weapons proliferation during half a century of man-controlled nuclear fission. An initial policy of denial did not work, a following period of cooperation needed a gradual strengthening of international assurances on the exclusively peaceful character of the flourishing use of nuclear techniques for power generation and of other applications. The focus of the nuclear weapon proliferation concern changed from the highly developed states to developing states. The Non-Proliferation Treaty laid the basis for a unique system of voluntarily accepted international inspections to verify the peaceful use of nuclear energy. The IAEA got the task to implement this 'Full Scope Safeguards' on all nuclear material and all nuclear activities in the non-nuclear weapon states. Thanks to the structure of the IAEA, in which both proponent and states with a critical attitude take part in the decision making process on the IAEA execution of its tasks, a balanced, and widely acceptable system emerged. International developments necessitated additional improvements of the non-proliferation system. The increase of strength of sub-national groups triggered international cooperation on physical protection, about a quarter of a century ago. More recently, it appeared that NPT states with assumed nuclear weapon ambitions operated in the margins between the interpretation of IAEA safeguards and the spirit and purpose of NPT. Improvements of the IAEA safeguards and a stronger cooperation between states, including the constraints which exporting states have imposed on nuclear supplies, strengthen the safeguards system. The important reductions in the two largest nuclear weapon arsenals lead, together with the delay in the fast breeder implementation, to large stockpiles of nuclear weapon usable materials. Also in this areas new internationally credible assurances have to be obtained, that these materials will never return to nuclear

IAEA safeguards and non-proliferation

Energy Technology Data Exchange (ETDEWEB)

Harry, R J.S.

1995-02-01

An overview is given of efforts to contain the nuclear weapons proliferation during half a century of man-controlled nuclear fission. An initial policy of denial did not work, a following period of cooperation needed a gradual strengthening of international assurances on the peaceful character of the flourishing use of nuclear techniques for power generation and of other applications. The focus of the nuclear weapon proliferation concern changed from the highly developed states to developing states. The Non-Proliferation Treaty laid the basis for a unique system of voluntarily accepted international inspections to verify the peaceful use of nuclear energy. The IAEA got the task to implement this `Full Scope Safeguards` on all nuclear material and all nuclear activities in the non-nuclear weapon states. Thanks to the structure of the IAEA, in which both proponent and states with a critical attitude take part in the decision making process on the IAEA execution of its tasks, a balanced, and widely acceptable system emerged. International developments necessitated additional improvements of the non-proliferation system. The increase of strength of sub-national groups triggered international cooperation on physical protection, about a quarter of a century ago. More recently, it appeared that NPT states with assumed nuclear weapon ambitions operated in the margins between the interpretation of IAEA safeguards and the spirit and purpose of NPT. Improvements of the IAEA safeguards and a stronger cooperation between states, including the constraints which exporting states have imposed on nuclear supplies, strengthen the safeguards system. The important reductions in the two largest nuclear weapon arsenals lead, together with the delay in the fast breeder implementation, to large stockpiles of nuclear weapon usable materials. Also in this areas new internationally credible assurances have to be obtained, that these materials will never return to nuclear weapon applications.

Need for Strengthening Nuclear Non-Proliferation and Safeguards Education to Prepare the Next Generation of Experts

International Nuclear Information System (INIS)

Janssens, W.A.M.; Peerani, P.; ); Gariazzo, C.; Ward, S.; Crete, J.-M.; Braunegger-Guelich, A.

2015-01-01

Although nuclear non-proliferation and safeguards are a continuous concern of the international community and discussed frequently at international fora and conferences, the academic world is not really on board with these topics. What we mean by this is that nuclear non-proliferation and safeguards is only very seldom part of a university curriculum. In the few cases where it does appear in the curriculum, whether in a nuclear engineering course or a political sciences master programme, it is typically covered only partially. Nuclear non-proliferation and safeguards are multidisciplinary and embrace, inter alia, historical, legal, technical, and political aspects. This is perhaps the reason why it is challenging for a single professor or university to develop and implement a comprehensive academic course or programme in this area. Professional organizations in this field, like the European Safeguards Research and Development Association (ESARDA) and the Institute for Nuclear Materials Management (INMM), have made first steps to address this issue by implementing specific educational activities. However, much more needs to be done. Therefore, ESARDA, INMM and the International Atomic Energy Agency (IAEA) are in the process of joining efforts to identify key elements and priorities to support universities in establishing appropriate and effective academic programmes in this area. This paper will share best practices, achievements and lessons learned by ESARDA, INMM and the IAEA in providing education and training to develop and maintain the expertise of nuclear non-proliferation and safeguards professionals. In addition, it will suggest potential ways on how to assist universities to get prepared for building-up the next generation of experts able to meet any future challenges in the area of non-proliferation and safeguards. (author)

Wet etch methods for InAs nanowire patterning and self-aligned electrical contacts

Science.gov (United States)

Fülöp, G.; d'Hollosy, S.; Hofstetter, L.; Baumgartner, A.; Nygård, J.; Schönenberger, C.; Csonka, S.

2016-05-01

Advanced synthesis of semiconductor nanowires (NWs) enables their application in diverse fields, notably in chemical and electrical sensing, photovoltaics, or quantum electronic devices. In particular, indium arsenide (InAs) NWs are an ideal platform for quantum devices, e.g. they may host topological Majorana states. While the synthesis has been continously perfected, only a few techniques have been developed to tailor individual NWs after growth. Here we present three wet chemical etch methods for the post-growth morphological engineering of InAs NWs on the sub-100 nm scale. The first two methods allow the formation of self-aligned electrical contacts to etched NWs, while the third method results in conical shaped NW profiles ideal for creating smooth electrical potential gradients and shallow barriers. Low temperature experiments show that NWs with etched segments have stable transport characteristics and can serve as building blocks of quantum electronic devices. As an example we report the formation of a single electrically stable quantum dot between two etched NW segments.

Static and low frequency noise characterization of ultra-thin body InAs MOSFETs

Science.gov (United States)

Karatsori, T. A.; Pastorek, M.; Theodorou, C. G.; Fadjie, A.; Wichmann, N.; Desplanque, L.; Wallart, X.; Bollaert, S.; Dimitriadis, C. A.; Ghibaudo, G.

2018-05-01

A complete static and low frequency noise characterization of ultra-thin body InAs MOSFETs is presented. Characterization techniques, such as the well-known Y-function method established for Si MOSFETs, are applied in order to extract the electrical parameters and study the behavior of these research grade devices. Additionally, the Lambert-W function parameter extraction methodology valid from weak to strong inversion is also used in order to verify its applicability in these experimental level devices. Moreover, a low-frequency noise characterization of the UTB InAs MOSFETs is presented, revealing carrier trapping/detrapping in slow oxide traps and remote Coulomb scattering as origin of 1/f noise, which allowed for the extraction of the oxide trap areal density. Finally, Lorentzian-like noise is also observed in the sub-micron area devices and attributed to both Random Telegraph Noise from oxide individual traps and g-r noise from the semiconductor interface.

Surface morphology and electronic structure of halogen etched InAs (1 1 1)

Energy Technology Data Exchange (ETDEWEB)

Eassa, N., E-mail: nashwa.eassa@nmmu.ac.za [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa); Murape, D.M. [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa); Betz, R. [Department of Chemistry, Nelson Mandela Metropolitan University (South Africa); Neethling, J.H.; Venter, A.; Botha, J.R. [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa)

2012-05-15

The reaction of halogen-based etchants with n-InAs (1 1 1)A and the resulting surface morphology and surface electronic structure are investigated using field emission scanning electron microscopy and Raman spectroscopy. Using the intensity ratio of the unscreened longitudinal optical (LO) phonon to the transverse optical (TO) phonon in the Raman spectrum, a significant reduction in band bending is deduced after exposure of the InAs surface to HCl:H{sub 2}O, Br-methanol and I-ethanol for moderate times and concentrations. These procedures also lead to smooth and defect-free InAs surfaces. The improvements in surface properties are reversed, however, if the concentrations of the etchants are increased or the etch time is too long. In the worst cases, pit formation and inverted pyramids with {l_brace}1 1 1{r_brace} side facets are observed. The influence of the etchant concentration and etch time on the morphological and electronic properties of the etched surfaces is reported.

Surface morphology and electronic structure of halogen etched InAs (1 1 1)

International Nuclear Information System (INIS)

Eassa, N.; Murape, D.M.; Betz, R.; Neethling, J.H.; Venter, A.; Botha, J.R.

2012-01-01

The reaction of halogen-based etchants with n-InAs (1 1 1)A and the resulting surface morphology and surface electronic structure are investigated using field emission scanning electron microscopy and Raman spectroscopy. Using the intensity ratio of the unscreened longitudinal optical (LO) phonon to the transverse optical (TO) phonon in the Raman spectrum, a significant reduction in band bending is deduced after exposure of the InAs surface to HCl:H 2 O, Br–methanol and I–ethanol for moderate times and concentrations. These procedures also lead to smooth and defect-free InAs surfaces. The improvements in surface properties are reversed, however, if the concentrations of the etchants are increased or the etch time is too long. In the worst cases, pit formation and inverted pyramids with {1 1 1} side facets are observed. The influence of the etchant concentration and etch time on the morphological and electronic properties of the etched surfaces is reported.

Tlatelolco regime and nonproliferation in Latin America

International Nuclear Information System (INIS)

Redick, J.R.

1981-01-01

The regime established by the Treaty of Tlatelolco supports peace and security in the Latin American region and global nonproliferation efforts. Circumstances leading to the creation of the nuclear-weapon-free zone include careful preparations and negotiations, individual leadership, existence of certain shared cultural and legal traditions of Latin American countries, and the temporary stimulus of the Cuban missile crisis. The lack of overt superpower pressure on Latin America, compared with more turbulent regions, has permitted continued progress toward full realization of the zone. Tlatelolco's negotiating process, as well as the substance of the Treaty, deserve careful consideration relative to other areas. The Treaty enjoys wide international approval, but full support by certain Latin American States (Argentina, Brazil, Chile, Cuba) has been negatively affected by the failure of the US Senate to ratify Tlatelolco's Protocol I. Nuclear programs of Argentina, Brazil, and Mexico are expanding rapidly and these nations are forming linkages with West European countries, rather than the United States. The May 1980 Argentine-Brazilian nuclear agreement foresees significant cooperation between the two nation's nuclear energy commissions and more coordinated resistance to the nuclear supplier countries. Argentine-Brazilian nuclear convergence and the response accorded to it by the United States will have significant implications for the future of the Tlatelolco regime and nonproliferation in Latin America. 52 references

Nuclear nonproliferation: Concerns with US delays in accepting foregin research reactors' spent fuel

International Nuclear Information System (INIS)

1994-01-01

One key US nonproliferation goal is to discourage use of highly enriched uranium fuel (HEU), which can be used to make nuclear bombs, in civilian nuclear programs worldwide. DOE's Off-Site Fuels Policy for taking back spent HEU from foreign research reactors was allowed to expire due to environmental reasons. This report provides information on the effects of delays in renewing the Off-Site Fuels Policy on US nonproliferation goals and programs (specifically the reduced enrichment program), DOE's efforts to renew the fuels policy, and the price to be charged to the operators of foreign reactors for DOE's activities in taking back spent fuel

Reconstruction of an InAs nanowire using geometric and algebraic tomography

International Nuclear Information System (INIS)

Pennington, R S; Boothroyd, C B; König, S; Alpers, A; Dunin-Borkowski, R E

2011-01-01

Geometric tomography and conventional algebraic tomography algorithms are used to reconstruct cross-sections of an InAs nanowire from a tilt series of experimental annular dark-field images. Both algorithms are also applied to a test object to assess what factors affect the reconstruction quality. When using the present algorithms, geometric tomography is faster, but artifacts in the reconstruction may be difficult to recognize.

Reconstruction of an InAs nanowire using geometric and algebraic tomography

DEFF Research Database (Denmark)

Pennington, Robert S.; König, S.; Alpers, A.

2011-01-01

Geometric tomography and conventional algebraic tomography algorithms are used to reconstruct cross-sections of an InAs nanowire from a tilt series of experimental annular dark-field images. Both algorithms are also applied to a test object to assess what factors affect the reconstruction quality....... When using the present algorithms, geometric tomography is faster, but artifacts in the reconstruction may be difficult to recognize....

Critical Temperature for the Conversion from Wurtzite to Zincblende of the Optical Emission of InAs Nanowires

KAUST Repository

Rota, Michele B.

2017-07-12

One hour annealing at 300 degrees C changes the optical emission characteristics of InAs nanowires (NWs) from the wurtzite (WZ) phase into that of zincblende (ZB). These results are accounted for by the conversion of a small fraction of the NW WZ metastable structure into the stable ZB structure. Several paths toward the polytype transformation in the configuration space are also demonstrated using first-principles calculations. For lower annealing temperatures, emission which is likely related to WZ polytypes is observed at energies that agree with theoretical predictions. These results demonstrate severe constraints on thermal processes to which devices made from InAs WZ NWs can be exposed.

The structure of German non-proliferation policy - past and future

International Nuclear Information System (INIS)

Mueller, H.

1990-01-01

West German nonproliferation policy has evolved through four phases: First German policy strived to regain the right to nuclear research and industrial development. Then West Germany struggled for participation in NATO nuclear decision-making. Following the conclusion of the NPT, the full development of a mature nuclear industry, including activities in the full fuel cycle, and the promotion of nuclear exports were the focus of national nuclear policy. Starting in the early eighties, political aspects became more important. International security, arms control and disarmament, and foreign reputation had a more prominent role than pure economic interests. In the future, the united Germany must take care not to repeat the sad scandals of the eighties. Its renunciation of nuclear weapons remains a pillar of European stability and a prerequisite for a European peace system. Together with its European partners, Germany can be expected to take a more active, supportive and effective role in international non-proliferation policy. (orig./HSCH) [de

Workshop on regional cooperation in remote monitoring for transparency and nonproliferation

International Nuclear Information System (INIS)

Olsen, John; Inoue, Naoko; Hori, Masato; Hashimoto, Yu; Mochiji, Toshiro

2006-06-01

The Workshop on Regional Cooperation in Remote Monitoring for Transparency and Nonproliferation on 8-9 February at O'arai, Japan, brought together remote monitoring experts to share technical experience and consider potential uses of remote monitoring for nuclear transparency and strengthened nonproliferation. Sponsored by the Nuclear Nonproliferation Science and Technology Center (NPSTC) of the Japan Atomic Energy Agency (JAEA), this event gathered thirty five attendees from the JAEA, the Republic of Korea's National Nuclear Management and Control Agency (NNCA), the International Atomic Energy Agency (IAEA), and U.S. Department of Energy/National Nuclear Security Administration (DOE/NNSA). U.S. technical experts represented Sandia National Laboratories (SNL) and Los Alamos National Laboratory (LANL). Workshop discussions and interactions met or surpassed all goals: On the technical front, the JAEA, NNCA, and SNL exchanged presentations on their respective uses and technical approaches to remote monitoring. These included systems for both international safeguards and transparency. The IAEA shared valuable guidance on future remote monitoring system requirements. Following the presentations SNL conducted training in remote monitoring for technical personnel. In parallel project planning discussions, the JAEA, NNCA, SNL and the U.S. DOE reaffirmed mutual interest in regional cooperation in remote monitoring that could eventuate in exchange of safeguards-related data. A productive off-the-record session by all parties considered the path forward and established intermediate steps and time scales. The 15 of the presented papers are indexed individually. (J.P.N.)

Arsenic flux dependence of island nucleation on InAs(001)

International Nuclear Information System (INIS)

Grosse, Frank; Barvosa-Carter, William; Zinck, Jenna; Wheeler, Matthew; Gyure, Mark F.

2002-01-01

The initial stages of InAs(001) homoepitaxial growth are investigated using a combination of kinetic Monte Carlo simulations based on ab initio density functional theory and scanning tunneling microscopy. In the two dimensional island nucleation mode investigated, the island number density is found to decrease with increasing As. This behavior is explained by a suppression of the effective In-adatom density leading to a reduction in island nucleation. The relevant microscopic processes responsible for this reduction are identified

Treaty on the non-proliferation of nuclear weapons

International Nuclear Information System (INIS)

ElBaradei, M.

2000-01-01

The document reproduces the statement of the Director General of the IAEA to the Review Conference of the Treaty on the Non-Proliferation of Nuclear Weapons, New York, 24 April 2000. The speech focus on the IAEA activities relevant to the implementation of the Treaty, namely: verification through the IAEA safeguards, peaceful nuclear co-operation in the field of human health, food and agriculture, water resources management, environmental pollution monitoring, training

Growth and characterization of InAs columnar quantum dots on GaAs substrate

International Nuclear Information System (INIS)

Li, L. H.; Patriarche, G.; Rossetti, M.; Fiore, A.

2007-01-01

The growth of InAs columnar quantum dots (CQDs) on GaAs substrates by molecular beam epitaxy was investigated. The CQDs were formed by depositing a 1.8 monolayer (ML) InAs seed dot layer and a short period GaAs/InAs superlattice (SL). It was found that the growth of the CQDs is very sensitive to growth interruption (GI) and growth temperature. Both longer GI and higher growth temperature impact the size dispersion of the CQDs, which causes the broadening of photoluminescence (PL) spectrum and the presence of the additional PL peak tails. By properly choosing the GI and the growth temperature, CQDs including GaAs (3 ML)/InAs (0.62 ML) SL with period number up to 35 without plastic relaxation were grown. The corresponding equivalent thickness of the SL is 41 nm which is two times higher than the theoretical critical thickness of the strained InGaAs layer with the same average In composition of 16%. The increase of the critical thickness is partially associated with the formation of the CQDs. Based on a five-stack CQD active region, laser diodes emitting around 1120 nm at room temperature were demonstrated, indicating a high material quality. CQDs with nearly isotropic cross section (20 nmx20 nm dimensions) were formed by depositing a 16-period GaAs (3 ML)/InAs (0.62 ML) SL on an InAs seed dot layer, indicating the feasibility of artificial shape engineering of QDs. Such a structure is expected to be very promising for polarization insensitive device applications, such as semiconductor optical amplifiers

Direct evidence of strain transfer for InAs island growth on compliant Si substrates

Energy Technology Data Exchange (ETDEWEB)

Marçal, L. A. B.; Magalhães-Paniago, R.; Malachias, Angelo, E-mail: angeloms@fisica.ufmg.br [Universidade Federal de Minas Gerais, Av. Antonio Carlos 6627, CEP 31270-901, Belo Horizonte (Brazil); Richard, M.-I. [European Synchrotron (ESRF), ID01 beamline, CS 40220, 38043 Grenoble Cedex 9 (France); Aix-Marseille University, IM2NP-CNRS, Faculté des Sciences de St Jérôme, 13397 Marseille (France); Cavallo, F. [Center for High Technology Materials, University of New Mexico, 1313 Goddard St., Albuquerque, New Mexico 87106 (United States); University of Wisconsin-Madison, 1500 Engineering Drive, Madison, Wisconsin 53706 (United States); Lagally, M. G. [University of Wisconsin-Madison, 1500 Engineering Drive, Madison, Wisconsin 53706 (United States); Schmidt, O. G. [Institute for Integrative Nanosciences, IFW-Dresden, D-01171 Dresden (Germany); Schülli, T. Ü. [European Synchrotron (ESRF), ID01 beamline, CS 40220, 38043 Grenoble Cedex 9 (France); Deneke, Ch. [Laboratório Nacional de Nanotecnologia (LNNano/CNPEM), C.P. 6192, CEP 13083-970, Campinas (Brazil)

2015-04-13

Semiconductor heteroepitaxy on top of thin compliant layers has been explored as a path to make inorganic electronics mechanically flexible as well as to integrate materials that cannot be grown directly on rigid substrates. Here, we show direct evidences of strain transfer for InAs islands on freestanding Si thin films (7 nm). Synchrotron X-ray diffraction measurements using a beam size of 300 × 700 nm{sup 2} can directly probe the strain status of the compliant substrate underneath deposited islands. Using a recently developed diffraction mapping technique, three-dimensional reciprocal space maps were reconstructed around the Si (004) peak for specific illuminated positions of the sample. The strain retrieved was analyzed using continuous elasticity theory via Finite-element simulations. The comparison of experiment and simulations yields the amount of strain from the InAs islands, which is transferred to the compliant Si thin film.

Functional display of ice nucleation protein InaZ on the surface of bacterial ghosts.

Science.gov (United States)

Kassmannhuber, Johannes; Rauscher, Mascha; Schöner, Lea; Witte, Angela; Lubitz, Werner

2017-09-03

In a concept study the ability to induce heterogeneous ice formation by Bacterial Ghosts (BGs) from Escherichia coli carrying ice nucleation protein InaZ from Pseudomonas syringae in their outer membrane was investigated by a droplet-freezing assay of ultra-pure water. As determined by the median freezing temperature and cumulative ice nucleation spectra it could be demonstrated that both the living recombinant E. coli and their corresponding BGs functionally display InaZ on their surface. Under the production conditions chosen both samples belong to type II ice-nucleation particles inducing ice formation at a temperature range of between -5.6 °C and -6.7 °C, respectively. One advantage for the application of such BGs over their living recombinant mother bacteria is that they are non-living native cell envelopes retaining the biophysical properties of ice nucleation and do no longer represent genetically modified organisms (GMOs).

Shubnikov-de Haas effect study of InAs after transmutation doping at low temperatures

International Nuclear Information System (INIS)

Gerstenberg, H.; Mueller, P.

1990-01-01

Degenerate InAs single crystals have been irradiated by thermal neutrons below 6 K. The Shubnikov-de Haas effect and the electrical resistivity have been measured as a function of the neutron dose and the annealing temperature. The effects of transmutation doping and simultaneous introduction of lattice defects have been analysed in terms of the conduction electron density and the scattering rates τ ρ -1 - ρne 2 /m * and τ x -1 2πkub(B)X/h/2π (where X is the Dingle temperature). The measured conduction electron density after irradiation and thermal annealing agreed well with the values calculated from the experimental and materials parameters. The effects of radiation damage may qualitatively be explained assuming neutral In vacancies to be the most common type of defect in thermal-neutron-irradiated InAs. A comparison with similar experiments on InSb is given. (author)

Plutonium: key issue in nuclear disarmament and non-proliferation of nuclear weapons

International Nuclear Information System (INIS)

Yoshisaki, M.B.

1993-01-01

The technical report is a 1993 update on weapons-grade plutonium, a key issue in nuclear disarmament. Its vital significance would again be discussed during the fifth and the last Review Conference on the Non-Proliferation Treaty (NPT) for Nuclear Weapons which would end in 1995. Member States shall decide whether an indefinite or conditional extension of NPT is necessary for world peace and international security. Two Non-NPT States, Russia and U.S.A. are in the forefront working for the reduction of nuclear weapons through nuclear disarmament. Their major effort is focused on the implementation of the Strategic Arms Reduction Treaty I and II or START I and II for world peace. The eventual implementation of START I and II would lead to the dismantling of plutonium from nuclear warheads proposed to be eliminated by both countries. This report gives three technical options to be derived from nuclear disarmament issues for the non-proliferation of nuclear weapons: (a) indefinite storage - there is no guarantee that these will not be used in the future (b) disposal as wastes - possible only in principle, because of lack of experience in mixing plutonium with high level wastes, and (c) source of energy - best option in managing stored weapons materials, because it satisfies non-proliferation objectives. It means fuel for energy in Light Water Reactors (LWR) or Fast Breeder Reactors (FBR). (author). 8 refs

Effects of growth temperature and arsenic pressure on size distribution and density of InAs quantum dots on Si (001)

International Nuclear Information System (INIS)

Zhao, Z.M.; Hul'ko, O.; Kim, H.J.; Liu, J.; Shi, B.; Xie, Y.H.

2005-01-01

InAs self-assembled quantum dots (QDs) were grown on Si (001) substrates via molecular beam epitaxy. The size distribution and density of InAs QDs grown under different conditions were studied using plan-view transmission electron microscopy. Dot density was shown to strongly depend on arsenic beam equivalent pressure (BEP) ranging from 2.8x10 -5 to 1.2x10 -3 Pa. In contrast, dot density was nearly independent of substrate temperature from 295 to 410 deg. C under constant arsenic BEP, while broadening of size distribution was observed with increasing temperature. The mechanism accounting for some of the main features of the experimental observations is discussed. Finally, InAs quantum dots with optimized narrow size distribution and high density were grown at low arsenic BEP of 7.2 x10 -5 Pa and low temperature of 250 deg. C followed by annealing at arsenic BEP of 1.9 x10 -4 Pa and temperature of 410 deg. C

The impact of non-proliferation policies on the uranium market - an industry view

International Nuclear Information System (INIS)

Stephany, M.

1977-01-01

It is concluded that from an economic point of view, the impact of the present political discussions on non-proliferation (referring particularly to U.S. and Canadian initiatives) on the uranium market (through the choice of reactor programmes in different countries, and other parts of the fuel cycle, such an enrichment, reprocessing, the use of plutonium and the disposal of radioactive waste) cannot be assessed quantitatively. It is believed, however, that in general terms the non-proliferation issue will lead to an increase in the cost of nuclear energy and of all energy. It is also considered that it will tend to strengthen nationalism and thereby to restrict international trade. (U.K.)

Supercurrent through a spin-split quasi-ballistic point contact in an InAs nanowire

DEFF Research Database (Denmark)

Saldaña, J. C. Estrada; Žitko, R.; Cleuziou, J. P.

2018-01-01

We study the superconducting proximity effect in an InAs nanowire contacted by Ta-based superconducting electrodes. Using local bottom gates, we control the potential landscape along the nanowire, tuning its conductance to a quasi-ballistic regime. At high magnetic field ($B$), we observe...

Tuning of Rashba/Dresselhaus Spin Splittings by Inserting Ultra-Thin InAs Layers at Interfaces in Insulating GaAs/AlGaAs Quantum Wells.

Science.gov (United States)

Yu, Jinling; Zeng, Xiaolin; Cheng, Shuying; Chen, Yonghai; Liu, Yu; Lai, Yunfeng; Zheng, Qiao; Ren, Jun

2016-12-01

The ratio of Rashba and Dresselhaus spin splittings of the (001)-grown GaAs/AlGaAs quantum wells (QWs), investigated by the spin photocurrent spectra induced by circular photogalvanic effect (CPGE) at inter-band excitation, has been effectively tuned by changing the well width of QWs and by inserting a one-monolayer-thick InAs layer at interfaces of GaAs/AlGaAs QWs. Reflectance difference spectroscopy (RDS) is also employed to study the interface asymmetry of the QWs, whose results are in good agreement with that obtained by CPGE measurements. It is demonstrated that the inserted ultra-thin InAs layers will not only introduce structure inversion asymmetry (SIA), but also result in additional interface inversion asymmetry (IIA), whose effect is much stronger in QWs with smaller well width. It is also found that the inserted InAs layer brings in larger SIA than IIA. The origins of the additional SIA and IIA introduced by the inserted ultra-thin InAs layer have been discussed.

Definition of Nuclear Material in Aspects of Nuclear Nonproliferation and Security

International Nuclear Information System (INIS)

Jeon, Ji Hye; Lee, Chan Suh

2014-01-01

Nuclear safety accidents directly affect human health but nuclear security incidents indirectly influence human, which demonstrates the reason why security receives less attention. However, it is acknowledged that nuclear terrorism is indeed one of the most dreadful threat humanity faces. As part of strengthening nuclear security as well as nonproliferation to response to the threat, we need a better understanding of the nuclear material which needs to be safe under the objective of nuclear security. In reality, practitioners implement safeguards and physical protection in compliance with the regulation text in domestic legislation. Thus, it is important to specify nuclear material clearly in law for effective implementation. Therefore, the definition of terminology related to nuclear material is explored herein, within the highest-level legislation on the safeguards and physical protection. First the definition in Korean legislation is analyzed. Then, so as to suggest some improvements, other international efforts are examined and some case studies are conducted on other states which have similar level of nuclear technology and industry to Korea. Finally, a draft of definition on nuclear material in perspective of nuclear nonproliferation and security is suggested based on the analysis below. The recommendation showed the draft nuclear material definition in nuclear control. The text will facilitate the understanding of nuclear material in the context of nuclear nonproliferation and security. It might provide appropriate provision for future legislation related to nuclear nonproliferation and security. For effective safeguards and physical protection measures, nuclear material should be presented with in a consistent manner as shown in the case of United Kingdom. It will be much more helpful if further material engineering studies on each nuclear material are produced. Multi-dimensional approach is required for the studies on the degree of efforts to divert

Definition of Nuclear Material in Aspects of Nuclear Nonproliferation and Security

Energy Technology Data Exchange (ETDEWEB)

Jeon, Ji Hye; Lee, Chan Suh [Korea Institute of Nuclear Nonproliferation and Control, Daejeon (Korea, Republic of)

2014-10-15

Nuclear safety accidents directly affect human health but nuclear security incidents indirectly influence human, which demonstrates the reason why security receives less attention. However, it is acknowledged that nuclear terrorism is indeed one of the most dreadful threat humanity faces. As part of strengthening nuclear security as well as nonproliferation to response to the threat, we need a better understanding of the nuclear material which needs to be safe under the objective of nuclear security. In reality, practitioners implement safeguards and physical protection in compliance with the regulation text in domestic legislation. Thus, it is important to specify nuclear material clearly in law for effective implementation. Therefore, the definition of terminology related to nuclear material is explored herein, within the highest-level legislation on the safeguards and physical protection. First the definition in Korean legislation is analyzed. Then, so as to suggest some improvements, other international efforts are examined and some case studies are conducted on other states which have similar level of nuclear technology and industry to Korea. Finally, a draft of definition on nuclear material in perspective of nuclear nonproliferation and security is suggested based on the analysis below. The recommendation showed the draft nuclear material definition in nuclear control. The text will facilitate the understanding of nuclear material in the context of nuclear nonproliferation and security. It might provide appropriate provision for future legislation related to nuclear nonproliferation and security. For effective safeguards and physical protection measures, nuclear material should be presented with in a consistent manner as shown in the case of United Kingdom. It will be much more helpful if further material engineering studies on each nuclear material are produced. Multi-dimensional approach is required for the studies on the degree of efforts to divert

Comparison between mini mental state examination (MMSE) and Montreal cognitive assessment Indonesian version (MoCA-Ina) as an early detection of cognitive impairments in post-stroke patients

Science.gov (United States)

Lestari, S.; Mistivani, I.; Rumende, C. M.; Kusumaningsih, W.

2017-08-01

Mild cognitive impairment (MCI) is defined as cognitive impairment that may never develop into dementia. Cognitive impairment is one long-term complication of a stroke. The Mini Mental State Examination (MMSE), which is commonly used as a screening tool for cognitive impairment, has a low sensitivity to detect cognitive impairment, especially MCI. Alternatively, the Montreal Cognitive Assessment Indonesian version (MoCA-Ina) has been reported to have a higher sensitivity than the MMSE. The aim of this study was to compare the proportion of MCI identified between the MMSE and MoCA-Ina in stroke patients. This was a cross-sectional study of stroke outpatients who attended the Polyclinic Neuromuscular Division, Rehabilitation Department, and Polyclinic Stroke, Neurology Department Cipto Mangunkusumo General Hospital, Jakarta. The proportion of MCI identified using the MMSE was 31.03% compared to 72.41% when using the MoCA-Ina. This difference was statistically significant (Fisher’s exact test, p = 0.033). The proportion of MCI in stroke patients was higher when using the MoCA-Ina compared to the MMSE. The MoCA-Ina should be used as an alternative in the early detection of MCI in stroke patients, especially those undergoing rehabilitation.

Contactless electroreflectance and photoluminescence of InAs quantum dots with GaInNAs barriers grown on GaAs substrate

International Nuclear Information System (INIS)

Motyka, M.; Kudrawiec, R.; Misiewicz, J.; Pucicki, D.; Tlaczala, M.; Fischer, M.; Marquardt, B.; Forchel, A.

2007-01-01

InAs quantum dots (QDs) with GaInNAs barriers grown on (001) GaAs substrate by molecular beam epitaxy have been studied by contactless electroreflectance (CER) and photoluminescence (PL) spectroscopies. It has been observed that the overgrowth of self-organized InAs QDs with GaInNAs layers effectively tunes the QD emission to the 1.3 μm spectral region. In case of PL spectra only one peak related to QD emission has been observed. In the case of CER spectra, in addition to a CER feature corresponding to the QD ground state, a rich spectrum of CER resonances related to optical transitions in InAs/GaInNAs/GaAs QW has been observed. It has been concluded that the application of GaInNAs instead InGaAs leads to better control of emission wavelength from InAs QDs since strains in GaInNAs can be tuned from compressive to tensile. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

International nuclear trade and nonproliferation

International Nuclear Information System (INIS)

Potter, W.C.

1990-01-01

The purpose of this book, the culmination of one phase of an ongoing international research project on nuclear suppliers and nonproliferation, is to explore the international political and economic dimensions of nuclear trade, especially as they pertain to the behavior of eleven emerging nuclear-supplier states. More specifically, the book sets forth a conceptual framework for analyzing international nuclear trade; details the domestic and external factors that shape the nuclear export policies of Argentina, Brazil, India, Israel, Japan, Pakistan, the People's Republic of China, South Korea, South Africa, Spain and Taiwan; and identifies and assesses alternative strategies for containing the new proliferation risks posed by these emerging suppliers. The book also describes an innovative effort to utilize a computer-based system for tracking international nuclear trade

Growth patterns of self-assembled InAs quantum dots near the two-dimensional to three-dimensional transition

Science.gov (United States)

Colocci, M.; Bogani, F.; Carraresi, L.; Mattolini, R.; Bosacchi, A.; Franchi, S.; Frigeri, P.; Rosa-Clot, M.; Taddei, S.

1997-06-01

Self-assembled InAs quantum dots have been grown by molecular beam epitaxy in such a way as to obtain a continuous variation of InAs coverages across the wafer. Structured photoluminescence spectra are observed after excitation of a large number of dots; deconvolution into Gaussian components yields narrow emission bands (full width at half-maximum 20-30 meV) separated in energy by an average spacing of 30-40 meV. We ascribe the individual bands of the photoluminescence spectra after low excitation to families of dots with similar shapes and with heights differing by one monolayer, as strongly supported by numerical calculations of the fundamental electronic transitions in quantum dot structures.

NNSA Nonproliferation Graduate Fellowship Program Annual Report June 2009 - May 2010

International Nuclear Information System (INIS)

Berkman, Clarissa O.; Fankhauser, Jana G.

2011-01-01

In 2009, the Nonproliferation Graduate Fellowship Program (NGFP) completed its 17th successful year in support of the NNSA's mission by developing future leaders in nonproliferation and promoting awareness of career opportunities. This annual report to reviews program activities from June 2009 through May 2010 - the fellowship term for the Class of 2009. Contents include: Welcome Letter (Mission Driven: It's all about results), Introduction, Structure of the NGFP, Program Management Highlights, Annual Lifecycle, Class of 2009 Incoming Fellows, Orientation, Global Support of the Mission, Career Development, Management of the Fellows, Performance Highlights, Closing Ceremony, Where They Are Now, Alumni Highlight - Mission Success: Exceptional Leaders from the NGFP, Class of 2009 Fall Recruitment Activities, Established Partnerships, Face-to-Face, Recruiting Results, Interviews, Hiring and Clearances, Introducing the Class of 2010, Class of 2011 Recruitment Strategy, On the Horizon, Appendix A: Class of 2010 Fellow Biographies.

NNSA Nonproliferation Graduate Fellowship Program Annual Report June 2009 - May 2010

Energy Technology Data Exchange (ETDEWEB)

Berkman, Clarissa O.; Fankhauser, Jana G.

2011-04-01

In 2009, the Nonproliferation Graduate Fellowship Program (NGFP) completed its 17th successful year in support of the NNSA’s mission by developing future leaders in nonproliferation and promoting awareness of career opportunities. This annual report to reviews program activities from June 2009 through May 2010 - the fellowship term for the Class of 2009. Contents include: Welcome Letter (Mission Driven: It’s all about results), Introduction, Structure of the NGFP, Program Management Highlights, Annual Lifecycle, Class of 2009 Incoming Fellows, Orientation, Global Support of the Mission, Career Development, Management of the Fellows, Performance Highlights, Closing Ceremony, Where They Are Now, Alumni Highlight - Mission Success: Exceptional Leaders from the NGFP, Class of 2009 Fall Recruitment Activities, Established Partnerships, Face-to-Face, Recruiting Results, Interviews, Hiring and Clearances, Introducing the Class of 2010, Class of 2011 Recruitment Strategy, On the Horizon, Appendix A: Class of 2010 Fellow Biographies

In situ surface and interface study of crystalline (3×1)-O on InAs

Energy Technology Data Exchange (ETDEWEB)

Qin, Xiaoye, E-mail: xxq102020@utdallas.edu; Wallace, Robert M., E-mail: rmwallace@utdallas.edu [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States); Wang, Wei-E.; Rodder, Mark S. [Advanced Logic Lab, Samsung Semiconductor, Inc., Austin, Texas 78754 (United States)

2016-07-25

The oxidation behavior of de-capped InAs (100) exposed to O{sub 2} gas at different temperatures is investigated in situ with high resolution of monochromatic x-ray photoelectron spectroscopy and low energy electron diffraction. The oxide chemical states and structure change dramatically with the substrate temperature. A (3 × 1) crystalline oxide layer on InAs is generated in a temperature range of 290–330 °C with a coexistence of In{sub 2}O and As{sub 2}O{sub 3}. The stability of the crystalline oxide upon the atomic layer deposition (ALD) of HfO{sub 2} is studied as well. It is found that the generated (3 × 1) crystalline oxide is stable upon ALD HfO{sub 2} growth at 100 °C.

Preparation for the Nuclear Non-Proliferation Treaty Extension Conference in 1995

International Nuclear Information System (INIS)

Chrzanowski, P.L.

1993-01-01

About 30 specialists in non-proliferation participated in a workshop to explore ideas for US Government preparatory steps leading to the 1995 Nuclear Non-Proliferation Treaty (NPT) Extension Conference. To that end, workshop sessions were devoted to reviewing the lessons learned from previous Review Conferences, discussing the threats to the non-proliferation regime together with ways of preserving and strengthening it, and examining the management of international nuclear commerce. A fundamental premise shared by workshop participants was that extension of the NPT is immensely important to international security. The importance of stemming proliferation and, more specifically, extending the Treaty, is growing as a result of the significant changes in the world. If the conferees of the Extension Conference decide on no extension or extension for a short limited duration, some technically advanced states that have foregone development of nuclear weapons may begin to rethink their options. Also, other arms control measures, such as the Chemical Weapons Convention, could start to unravel. The US must provide strong international leadership to ensure that the Extension Conference is a success, resulting in Treaty extension, perhaps through successive terms, into the indefinite future. Workshop participants were struck by the urgent need for the US to take organizational steps so that it is highly effective in its advance preparations for the Extension Conference. Moreover, the Extension Conference provides both a challenge and an opportunity to mold a cohesive set of US policy actions to define the future role of nuclear weapons and combat their proliferation

Transport and performance of a gate all around InAs nanowire transistor

International Nuclear Information System (INIS)

Alam, Khairul

2009-01-01

The transport physics and performance metrics of a gate all around an InAs nanowire transistor are studied using a three-dimensional quantum simulation. The transistor action of an InAs nanowire transistor occurs by modulating the transmission coefficient of the device. This action is different from a conventional metal-oxide-semiconductor field effect transistor, where the transistor action occurs by modulating the charge in the channel. The device has 82% tunneling current in the off-state and 81% thermal current in the on-state. The two current components become equal at a gate bias at which an approximate source-channel flat-band condition is achieved. Prior to this gate bias, the tunneling current dominates and the thermal current dominates beyond it. The device has an on/off current ratio of 7.84 × 10 5 and an inverse subthreshold slope of 63 mV dec −1 . The transistor operates in the quantum capacitance limit with a normalized transconductance value of 14.43 mS µm −1 , an intrinsic switching delay of 90.1675 fs, and an intrinsic unity current gain frequency of 6.8697 THz

Study of electron transport in n-type InAs substrate by Monte Carlo ...

African Journals Online (AJOL)

It is therefore an iterative process made up from a whole coasting flights stopped by acoustics interactions, polar and non polar optics, piezoelectric, inter-valley, impurity, ionization and surface. By applying this method to the III-V material, case of InAs, we have described the behavior of the carriers from dynamic and ...

Nonproliferation of Nuclear Weapons and the Nuclear Program of the DPRK

Directory of Open Access Journals (Sweden)

- Park Sang Hoon

2012-09-01

Full Text Available The article analyzes the contemporary aspects of the nuclear weapon nonproliferation issue as exemplified by the international approaches to the DPRK nuclear weapons program, as well as the international community efforts to resolve it, in particular via the Six-Party Talks.

The Nuclear Progress And The Non-Proliferation Policies

Energy Technology Data Exchange (ETDEWEB)

Popa-Simil, Liviu [Los Alamos, NM 87544 (United States)

2009-06-15

The 2008 fall crisis showed the limits of globalization under the actual rules and de-regulations promoted by few developed countries. It also showed the weakness of the planetary economy induced by strong economic connections that makes the propagation of crises faster than the spread of welfare. The increase in severe weather and natural disasters showed how fast the civilization can be spoiled while the competition for oil resources made the interstate tensions grow. For almost all states, the development of the nuclear power becomes a prime option, even oil producers started to show interest in nuclear technology and also, policies that in particular are clearly oriented towards national development policies. The fact that anybody mastering nuclear technologies and uses for power production is capable in a reasonable time to produce weapons is a well-known fact. Therefore, in order to reduce the proliferation risk it is necessary to contain the nuclear science development. An alternative is to shift the weight in promoting renewable energies, as potential future energy alternative. Considering rigorously the future climate change effects, it becomes obvious that any delay in nuclear development will turn very costly for any nation ignoring all these facts and, the complexity of the real nonproliferation is growing. This new trend raises serious challenges in front of all states regarding the non-proliferation and, in order to keep control and stimulate a sound nuclear development, some of the actual non-proliferation concepts and policies have to be reformulated and enhanced. This has to be done in parallel with a more intensive implication of the international organisms in the real development of the nuclear power at national level. The large diversity of nuclear applications with huge collateral implication in every national economy makes the role of the international organisms orders of magnitude more important. The new challenges posed in front of the

ODNOS ZAPOSLENIH V VRTCU DO ZDRAVEGA NAČINA ŽIVLJENJA

OpenAIRE

Cesarec, Anja

2009-01-01

Diplomsko delo predstavlja temo odnos zaposlenih v vrtcu do zdravega načina življenja. Predstavili smo zdravje, dejavnike, ki vplivajo na stopnjo zdravja in dejavnike, ki vplivajo na življenjski slog, kot so kajenje tobaka, način prehranjevanja, telesno aktivnost, uživanje nedovoljenih drog in alkohola ter stres. Posebno poglavje pa je namenjeno skrbi za zdrav način življenja. V empiričnem delu so predstavljeni rezultati raziskave, narejene v vrtcu Rogaška Slatina, enota Izvir. V raziskavo, k...

U.S.-China commercial nuclear commerce: Nonproliferation and trade issues

International Nuclear Information System (INIS)

1997-01-01

The report concludes that the United States should not be denied access to the Chinese nuclear energy program. To the contrary, the report finds that--provided China meets the requisite nonproliferation criteria--it is strongly in the US national interest to engage in peaceful nuclear, cooperation with China, from security, environmental, safety, and economic perspectives

Non-Proliferation, the IAEA Safeguards System, and the importance of nuclear material measurements

Energy Technology Data Exchange (ETDEWEB)

Stevens, Rebecca S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-09-18

The objective of this project is to explain the contribution of nuclear material measurements to the system of international verification of State declarations and the non-proliferation of nuclear weapons.

Cavity pressure/residual stress measurements from the Non-Proliferation Experiment

Energy Technology Data Exchange (ETDEWEB)

Heinle, R.A.; Hudson, B.C. [Lawrence Livermore National Lab., CA (United States); Hatch, M.A. Jr.

1994-12-31

The Lawrence Livermore National Laboratory planned and conducted experiments on the Non-Proliferation Experiment to determine post-detonation gas pressure inside the explosive cavity and the residual rock stress in the region immediately outside the cavity. Before detonation there was significant concern that steam and detonation products would create very high temperatures and pressure in the blast cavity that would exist for weeks and months after firing. This could constitute a safety hazard to personnel re-entering the tunnel. Consequently the Lawrence Livermore National Laboratory was asked to field its Cavity Pressure/Residual stress monitor system on the Non-Proliferation Experiment. We obtained experimental data for the first 600 ms after the explosion and again several weeks after detonation upon tunnel re-entry. We recorded early-time cavity pressure of about 8.3 MPa. In addition we believe that the ends of our sensor hoses were subjected to an ambient driving pressure of about 0.5 MPa (absolute) that persisted until at least three weeks after zero time.

Self-Assembled InAs Nanowires as Optical Reflectors

Directory of Open Access Journals (Sweden)

Francesco Floris

2017-11-01

Full Text Available Subwavelength nanostructured surfaces are realized with self-assembled vertically-aligned InAs nanowires, and their functionalities as optical reflectors are investigated. In our system, polarization-resolved specular reflectance displays strong modulations as a function of incident photon energy and angle. An effective-medium model allows one to rationalize the experimental findings in the long wavelength regime, whereas numerical simulations fully reproduce the experimental outcomes in the entire frequency range. The impact of the refractive index of the medium surrounding the nanostructure assembly on the reflectance was estimated. In view of the present results, sensing schemes compatible with microfluidic technologies and routes to innovative nanowire-based optical elements are discussed.

JAEA's actions and contributions to the strengthening of nuclear non-proliferation

Science.gov (United States)

Suda, Kazunori; Suzuki, Mitsutoshi; Michiji, Toshiro

2012-06-01

Japan, a non-nuclear weapons state, has established a commercial nuclear fuel cycle including LWRs, and now is developing a fast neutron reactor fuel cycle as part of the next generation nuclear energy system, with commercial operation targeted for 2050. Japan Atomic Energy Agency (JAEA) is the independent administrative agency for conducting comprehensive nuclear R&D in Japan after the merger of Japan Atomic Energy Research Institute (JAERI) and Japan Nuclear Cycle Development Institute (JNC). JAEA and its predecessors have extensive experience in R&D, facility operations, and safeguards development and implementation for new types of nuclear facilities for the peaceful use of nuclear energy. As the operator of various nuclear fuel cycle facilities and numerous nuclear materials, JAEA makes international contributions to strengthen nuclear non-proliferation. This paper provides an overview of JAEA's development of nuclear non-proliferation and safeguards technologies, including remote monitoring of nuclear facilities, environmental sample analysis methods and new efforts since the 2010 Nuclear Security Summit in Washington D.C.

Back-end of the fuel cycle and non-proliferation strategies

Energy Technology Data Exchange (ETDEWEB)

Chebeskov, A.N.; Oussanov, V.I.; Iougai, S.V.; Pshakin, G.M. [Institute of Physics and Power Engineering, State Scientific Center of Russian Federation, Obninsk (Russian Federation)

2001-07-01

The paper focuses on the problem of fissile materials proliferation risk estimation. Some methodological approaches to the solution of this task and results of their application for comparison of different nuclear fuel cycle strategies are discussed. The results of comparative assessment of non-proliferation aspects of plutonium utilization alternatives in Russia using system analysis approach are presented. (author)

Back-end of the fuel cycle and non-proliferation strategies

International Nuclear Information System (INIS)

Chebeskov, A.N.; Oussanov, V.I.; Iougai, S.V.; Pshakin, G.M.

2001-01-01

The paper focuses on the problem of fissile materials proliferation risk estimation. Some methodological approaches to the solution of this task and results of their application for comparison of different nuclear fuel cycle strategies are discussed. The results of comparative assessment of non-proliferation aspects of plutonium utilization alternatives in Russia using system analysis approach are presented. (author)

Controlling the size of InAs quantum dots on Si1-xGex/Si(0 0 1) by metalorganic vapor-phase epitaxy

International Nuclear Information System (INIS)

Kawaguchi, Kenichi; Ebe, Hiroji; Ekawa, Mitsuru; Sugama, Akio; Arakawa, Yasuhiko

2009-01-01

The formation of III-V InAs quantum dots (QDs) on group-IV Si 1-x Ge x /Si(0 0 1) was investigated by metalorganic vapor-phase epitaxy. Two types of QDs, round-shaped QDs and giant QDs elongated in the [1 1 0] or [1,-1,0] direction, were observed in a growth condition of low V/III ratios. An increase in the V/III ratio and AsH 3 preflow during the cooling process was found to suppress the formation of giant QDs. It was considered that replacing the H-stabilized SiGe surface with the As-stabilized surface was necessary for increasing the QD nucleation. The size and density of InAs QDs on SiGe were controllable as well as that on III-V semiconductor buffer layers, and InAs QDs with a density as high as 5 x 10 10 cm -2 were obtained.

Joint DOE-PNC research on the use of transparency in support of nuclear nonproliferation

International Nuclear Information System (INIS)

Mochiji, Toshiro; Keeney, R.; Tazaki, Makiko; Nakhleh, C.; Puckett, J.; Stanbro, W.

1999-01-01

PNC and LANL collaborated in research on the concept of transparency in nuclear nonproliferation. The research was based on the Action Sheet No. 21, which was signed in February 1996, ''The Joint Research on Transparency in Nuclear Nonproliferation'' under the ''Agreement between the Power Reactor and Nuclear Fuel Development Corporation of Japan (PNC) and the US Department of Energy (DOE) for Cooperation in Research and Development Concerning Nuclear Material Control and Accounting Measures for Safeguards and Nonproliferation''. The purpose of Action Sheet 21 is to provide a fundamental study on Transparency to clarify the means to improve worldwide acceptability for the nuclear energy from the nuclear nonproliferation point of view. This project consists of independent research and then joint discussion at workshops that address a series of topics and issues in transparency. The activities covered in Action Sheet 21 took place over a period of 18 months. Three workshops were held; the first and the third hosted by PNC in Tokyo, Japan and the second hosted by LANL in Los Alamos, New Mexico, US. The following is a summary of the three workshops. The first workshop addressed the policy environment of transparency. Each side presented its perspective on the following issues: (1) a definition of transparency, (2) reasons for transparency, (3) detailed goals of transparency and (4) obstacles to transparency. The topic of the second workshop was ''Development of Transparency Options.'' The activities accomplished were (1) identify type of facilities where transparency might be applied, (2) define criteria for applying transparency, and (3) delineate applicable transparency options. The goal of the third workshop, ''Technical Options for Transparency,'' was to (1) identify conceptual options for transparency system design; (2) identify instrumentation, measurement, data collection and data processing options; (3) identify data display options; and (4) identify technical

Composition, morphology and surface recombination rate of HCl-isopropanol treated and vacuum annealed InAs(1 1 1)A surfaces

Energy Technology Data Exchange (ETDEWEB)

Kesler, V.G., E-mail: kesler@isp.nsc.ru [Institute of Semiconductor Physics SB RAS, Lavrentiev av., 13, Novosibirsk 630090 (Russian Federation); Seleznev, V.A.; Kovchavtsev, A.P.; Guzev, A.A. [Institute of Semiconductor Physics SB RAS, Lavrentiev av., 13, Novosibirsk 630090 (Russian Federation)

2010-05-01

X-ray photoelectron spectroscopy and atomic force microscopy were used to examine the chemical composition and surface morphology of InAs(1 1 1)A surface chemically etched in isopropanol-hydrochloric acid solution (HCl-iPA) and subsequently annealed in vacuum in the temperature range 200-500 deg. C. Etching for 2-30 min resulted in the formation of 'pits' and 'hillocks' on the sample surface, respectively 1-2 nm deep and high, with lateral dimensions 50-100 nm. The observed local formations, whose density was up to 3 x 10{sup 8} cm{sup -2}, entirely vanished from the surface after the samples were vacuum-annealed at temperatures above 300 deg. C. Using a direct method, electron beam microanalysis, we have determined that the defects of the hillock type includes oxygen and excessive As, while the 'pits' proved to be identical in their chemical composition to InAs. Vacuum anneals were found to cause a decrease in As surface concentration relative to In on InAs surface, with a concomitant rise of surface recombination rate.

Composition, morphology and surface recombination rate of HCl-isopropanol treated and vacuum annealed InAs(1 1 1)A surfaces

Science.gov (United States)

Kesler, V. G.; Seleznev, V. A.; Kovchavtsev, A. P.; Guzev, A. A.

2010-05-01

X-ray photoelectron spectroscopy and atomic force microscopy were used to examine the chemical composition and surface morphology of InAs(1 1 1)A surface chemically etched in isopropanol-hydrochloric acid solution (HCl-iPA) and subsequently annealed in vacuum in the temperature range 200-500 °C. Etching for 2-30 min resulted in the formation of "pits" and "hillocks" on the sample surface, respectively 1-2 nm deep and high, with lateral dimensions 50-100 nm. The observed local formations, whose density was up to 3 × 10 8 cm -2, entirely vanished from the surface after the samples were vacuum-annealed at temperatures above 300 °C. Using a direct method, electron beam microanalysis, we have determined that the defects of the hillock type includes oxygen and excessive As, while the "pits" proved to be identical in their chemical composition to InAs. Vacuum anneals were found to cause a decrease in As surface concentration relative to In on InAs surface, with a concomitant rise of surface recombination rate.

Composition, morphology and surface recombination rate of HCl-isopropanol treated and vacuum annealed InAs(1 1 1)A surfaces

International Nuclear Information System (INIS)

Kesler, V.G.; Seleznev, V.A.; Kovchavtsev, A.P.; Guzev, A.A.

2010-01-01

X-ray photoelectron spectroscopy and atomic force microscopy were used to examine the chemical composition and surface morphology of InAs(1 1 1)A surface chemically etched in isopropanol-hydrochloric acid solution (HCl-iPA) and subsequently annealed in vacuum in the temperature range 200-500 deg. C. Etching for 2-30 min resulted in the formation of 'pits' and 'hillocks' on the sample surface, respectively 1-2 nm deep and high, with lateral dimensions 50-100 nm. The observed local formations, whose density was up to 3 x 10 8 cm -2 , entirely vanished from the surface after the samples were vacuum-annealed at temperatures above 300 deg. C. Using a direct method, electron beam microanalysis, we have determined that the defects of the hillock type includes oxygen and excessive As, while the 'pits' proved to be identical in their chemical composition to InAs. Vacuum anneals were found to cause a decrease in As surface concentration relative to In on InAs surface, with a concomitant rise of surface recombination rate.

Jačina sveze adhezijskih materijala na tvrda zubna tkiva

OpenAIRE

Žagar, Polona

2017-01-01

Adhezija se odnosi na povezivanje atoma i molekula na kontaktnim površinama različitih materijala. Adhezijske sustave možemo podjeliti prema interakciji sa tvrdim zubnim tkivima na jetkajuće ispirajuće, samojetkajuće i staklenoionomerne sustave. Univerzalni adhezivi su najnovija generacija adheziva na tržištu. Mogu se koristiti kao jetkajući ispirajući i samojetkajući sustavi. U ovom radu je ispitivana jačina adhezijske sveze s caklinom jetkajuće ispirajućim i univerzalnim adheziv...

Selective area growth of InAs nanowires from SiO2/Si(1 1 1) templates direct-written by focused helium ion beam technology

Science.gov (United States)

Yang, Che-Wei; Chen, Wei-Chieh; Chou, Chieh; Lin, Hao-Hsiung

2018-02-01

We report on the selective area growth of InAs nanowires on patterned SiO2/Si (1 1 1) nano-holes, prepared by focused helium ion beam technology. We used a single spot mode, in which the focused helium ion beam was fixed on a single point with a He+-ion dosage, ranging from 1.5 pC to 8 pC, to drill the nano-holes. The smallest hole diameter achieved is ∼8 nm. We found that low He+-ion dosage is able to facilitate the nucleation of (1 1 1)B InAs on the highly mismatched Si, leading to the vertical growth of InAs nanowires (NWs). High He-ion dosage, on the contrary, severely damaged Si surface, resulting in tilted and stripe-like NWs. In addition to titled NW grown from (1 1 1)A InAs domain, a new titled growth direction due to defect induced twinning was observed. Cross-sectional TEM images of vertical NWs show mixed wurtizite (WZ) and zincblende (ZB) phases, while WZ phase dominants. The stacking faults resulting from the phase change is proportional to NW diameter, suggesting that the critical diameter of phase turning is larger than 110 nm, the maximum diameter of our NWs. Period of misfit dislocation at the InAs/Si interface of vertical NW is also found larger than the theoretical value when the diameter of heterointerface is smaller than 50 nm, indicating that the small contact area is able to accommodate the large lattice and thermal mismatch between InAs and Si.

Review of international forum on peaceful use of nuclear energy and nuclear non-proliferation

International Nuclear Information System (INIS)

Shimizu, Ryo; Suzuki, Mitsutoshi; Sakurai, Satoshi; Tamai, Hiroshi; Yamamura, Tsukasa; Kuno, Yusuke

2012-02-01

International forum on peaceful use of nuclear energy and nuclear non-proliferation was held at Gakushi-kaikan, Tokyo on February 2-3, 2011 in cooperation with The Japan Institute of International Affairs (JIIA) and The University of Tokyo Global COE. In our International Forum, we would like to encourage active discussion of international challenges to and solutions for compatibility between peaceful use of nuclear energy and nuclear non-proliferation, and international cooperation for emerging nuclear energy states. It was successfully carried out with as many as 310 participants and a lot of discussions. This report includes abstracts of keynote speeches, summary of panel discussions and materials of the presentations in the forum. (author)

Absorption coefficients for interband optical transitions in a strained InAs1−xPx/InP quantum wire

International Nuclear Information System (INIS)

Saravanan, S.; John Peter, A.; Lee, Chang Woo

2014-01-01

Excitons confined in an InAs 1−x P x /InP (x=0.2) quantum well wire are studied in the presence of magnetic field strength. Numerical calculations are carried out using variational approach within the single band effective mass approximation. The compressive strain contribution to the confinement potential is included throughout the calculations. The energy difference of the ground and the first excited state is investigated in the influence of magnetic field strength taking into account the geometrical confinement effect. The magnetic field induced optical band as a function of wire radius is investigated in the InAs 0.8 P 0.2 /InP quantum well wire. The valence-band anisotropy is included in our theoretical model by employing different hole masses in different spatial directions. The optical gain as a function of incident photon energy is computed in the presence of magnetic field strength. The corresponding 1.55 μm wavelength is achieved for 40 Å InAs 0.8 P 0.2 /InP quantum well wire. We hope that the results could be used for the potential applications in fiber optic communications. -- Highlights: • Magnetic field induced excitons confined in a InAs 1−x P x /InP (x=0.2) quantum well wire are studied. • The compressive strain is included throughout the calculations. • The energy difference of the ground and the first excited state is investigated in the presence of magnetic field strength. • The magnetic field induced optical band with the geometrical confinement is studied. • The optical gain with the photon energy is computed in the presence of magnetic field strength

JAEA's efforts for regional transparency in the area of nuclear nonproliferation

International Nuclear Information System (INIS)

Hoffheins, Barbara; Kawakubo, Yoko; Inoue, Naoko

2014-03-01

The Japan Atomic Energy Agency (JAEA) has undertaken a joint R and D project with the US Department of Energy's National Nuclear Security Administration (DOE/NNSA) for the purposes of developing an Information Sharing Framework (ISF) for regional nonproliferation cooperation since July 2011. This project builds on nearly twenty years of technical cooperation between JAEA, its predecessor organizations and the DOE including the activities to define, develop and test transparency technologies and other multilateral efforts. The objective of current project is to design a viable information sharing process to support the goals of building confidence in the peaceful nature of regional nuclear programs. At the end of a two-year-effort, project partners, JAEA and Sandia National Laboratories (SNL), have defined the comprehensive requirements for an ISF that will ensure nonproliferation transparency success and sustainability. In October 2011, a parallel project with the similar title and objective was launched under the arrangement between the US DOE/NNSA and the Republic of Korea Ministry of Education, Science and Technology (MEST). Since then, JAEA, SNL, the Korea Institute for Nuclear Nonproliferation and Control (KINAC) and Korea Atomic Energy Institute (KAERI) have jointly carried out the project in a form of informal, multilateral cooperation. The project partners have identified needs and audience for ISF, and initiated the discussion to develop requirements for ISF through workshops, meetings, regular telephone conferences, etc. The activities include conducting a survey to identify stakeholders' needs and requirements for an ISF, launching a website to practice information sharing concepts, and presenting papers. This paper provides the historical context of the current project to establish ISF, and reports the progress to date and speculates on future directions. (author)

Thermal conductivity of InAs quantum dot stacks using AlAs strain compensating layers on InP substrate

International Nuclear Information System (INIS)

Salman, S.; Folliot, H.; Le Pouliquen, J.; Chevalier, N.; Rohel, T.; Paranthoën, C.; Bertru, N.; Labbé, C.; Letoublon, A.; Le Corre, A.

2012-01-01

Highlights: ► The thermal conductivity of InAs on InP (1 1 3)B quantum dots stacks is measured. ► The growth of a close stack of 100 layers of InAs using AlAs strain compensating layers is presented. ► New data on the thermal conductivity of InP n-doped susbtrate are given. - Abstract: The growth and thermal conductivity of InAs quantum dot (QD) stacks embedded in GaInAs matrix with AlAs compensating layers deposited on (1 1 3)B InP substrate are presented. The effect of the strain compensating AlAs layer is demonstrated through Atomic Force Microscopy (AFM) and X-ray diffraction structural analysis. The thermal conductivity (2.7 W/m K at 300 K) measured by the 3ω method reveals to be clearly reduced in comparison with a bulk InGaAs layer (5 W/m K). In addition, the thermal conductivity measurements of S doped InP substrates and the SiN insulating layer used in the 3ω method in the 20–200 °C range are also presented. An empirical law is proposed for the S doped InP substrate, which slightly differs from previously presented results.

Simulation of quantum dots size and spacing effect for intermediate band solar cell application based on InAs quantum dots arrangement in GaAs

Energy Technology Data Exchange (ETDEWEB)

Hendra, P. I. B., E-mail: ib.hendra@gmail.com; Rahayu, F., E-mail: ib.hendra@gmail.com; Darma, Y., E-mail: ib.hendra@gmail.com [Physical Vapor Deposition Laboratory, Physics of Material Electronics Research, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia)

2014-03-24

Intermediate band solar cell (IBSC) has become a promising technology in increasing solar cell efficiency. In this work we compare absorption coefficient profile between InAs quantum dots with GaAs bulk. We calculate the efficiency of GaAs bulk and GaAs doped with 2, 5, and 10 nm InAs quantum dot. Effective distances in quantum dot arrangement based on electron tunneling consideration were also calculated. We presented a simple calculation method with low computing power demand. Results showed that arrangement of quantum dot InAs in GaAs can increase solar cell efficiency from 23.9 % initially up to 60.4%. The effective distance between two quantum dots was found 2 nm in order to give adequate distance to prevent electron tunneling and wave functions overlap.

Electron Spin Polarization and Detection in InAs Quantum Dots Through p-Shell Trions

Science.gov (United States)

2010-01-08

optical control of spin states in quantum dots. II. EXPERIMENT The QD sample consists of 20 layers of InAs QDs, grown by molecular -beam epitaxy through...anisotropic 2D harmonic poten- tials. The electrons and holes are described by Fock- Darwin states harmonic oscillators with lateral sizes ax and ay in this

Spin interactions in InAs quantum dots

Science.gov (United States)

Doty, M. F.; Ware, M. E.; Stinaff, E. A.; Scheibner, M.; Bracker, A. S.; Gammon, D.; Ponomarev, I. V.; Reinecke, T. L.; Korenev, V. L.

2006-03-01

Fine structure splittings in optical spectra of self-assembled InAs quantum dots (QDs) generally arise from spin interactions between particles confined in the dots. We present experimental studies of the fine structure that arises from multiple charges confined in a single dot [1] or in molecular orbitals of coupled pairs of dots. To probe the underlying spin interactions we inject particles with a known spin orientation (by using polarized light to perform photoluminescence excitation spectroscopy experiments) or use a magnetic field to orient and/or mix the spin states. We develop a model of the spin interactions that aids in the development of quantum information processing applications based on controllable interactions between spins confined to QDs. [1] Polarized Fine Structure in the Photoluminescence Excitation Spectrum of a Negatively Charged Quantum Dot, Phys. Rev. Lett. 95, 177403 (2005)

Stimulated Emission from InAs (GaAs Monolayers Stacks Embedded in Al0.33Ga0.67As Ective Region

Directory of Open Access Journals (Sweden)

Dusan Pudis

2002-01-01

Full Text Available Our study is focused on the optical and electronic properties of InAs (GaAs monolayers embedded in Al0.33GA0.67As barrier layers investigated by temperature dependencies of electroluminescence spectra. The experimental results obtained from low temperature electroluminescence measurements of InAs (GaAs/Al0.33GA0.67As revealed the excellent emission spectra in the visib le range 630-690 nm. The stimulated emission from these structures across their cleavage planes has been observed at low  temperatures what is highly interesting for potential device applications.

Dynamics of postirradiation intracellular cysteine and aspartic proteinases profiles in proliferating and nonproliferating mammalian cells

International Nuclear Information System (INIS)

Korbelik, M.; Osmak, M.; Suhar, A.; Turk, V.; Skrk, J.

1990-01-01

Dynamics of postirradiation intracellular cysteine and aspartic proteinases profiles were examined in proliferating and nonproliferating Chinese hamster fibroblasts (V 79). The results show that there are significant alterations in cysteine and aspartic intracellular proteinases activity already in the early postirradiation period, which are different in proliferating and nonproliferating cells. Irradiation of the cells examined to low doses and up to 15 Gy induced an increase in cysteine proteinases activity in the early postexposure period, while at higher irradiation doses applied, the activity of these proteinases was decreased. These observations suggest that intracellular proteinases are actively participating in process involving recovery from radiation injury or cell killing. (orig.) [de

The third review conference of the parties of the Treaty on Non-Proliferation of Nuclear Weapons, and recent developments concerning international safeguards

International Nuclear Information System (INIS)

Canty, M.J.; Richter, B.; Schlupp, C.; Stein, G.

1986-11-01

The non-proliferation activities and instruments are listed in a table. The two main instruments are the Non-Proliferation Treaty and the IAEA Safeguards, which are supplemented by treaties of regional restricted effects, such as the Treaty of Tlatelolco and the EURATOM treaty. The two-tier structure of the treaties, i.e. to provide for non-proliferation of nuclear weapons and at the same time foster the peaceful uses of nuclear energy, has proven to have a particularly stabilizing effect, which was confirmed by the last Review Conference of the Parties to the Treaty on Non-Proliferation. The conference members were particularly satisfied with the results of the IAEA Safeguards. Future developments towards improving international safeguards will concentrate on operator-friendly and financially reasonable safeguards measures, such as safeguards effectiveness evaluations and near-real-time accountancy. The results of the CAS discussions on the definition of principles and goals of co-operation for the peaceful uses of nuclear energy are of importance also to the PUNE conference. The PUNE conference will be held in 1987 and is expected to yield points of orientation for further embedding the non-proliferation principle in the international co-operative activities and the nuclear business in the 1980s. (orig./HP) [de

Spin Qubits in GaAs Heterostructures and Gating of InAs Nanowires for Lowtemperature Measurements

DEFF Research Database (Denmark)

Nissen, Peter Dahl

of the contenders in the race to build a large-scale quantum computer, is such a component, and research aiming to build, manipulate and couple spin qubits is looking at many materials systems to nd one where the requirements for fast control and long coherence time can be combined with ecient coupling between...... distant qubits. This thesis presents electric measurement on two of the materials systems currently at the forefront of the spin qubit race, namely InAs nanowires and GaAs/AlGaAs heterostructures. For the InAs nanowires we investigate dierent gating geometries towards the goal of dening stable quantum...... electrodes induces tunable barriers of up to 0:25 eV. From the temperature dependence of the conductance, the barrier height is extracted and mapped as a function of gate voltage. Top and bottom gates are similar to each other in terms of electrostatic couplings (lever arms 0:10:2 eV=V) and threshold...

Comparative study of porosification in InAs, InP, ZnSe and ZnCdS

International Nuclear Information System (INIS)

Monaico, Eduard; Tiginyanu, Ion; Nielsch, Kornelius; Ursaki, Veaceslav; Colibaba, Gleb; Nedeoglo, Dmitrii; Cojocaru, Ala; Foell Helmut

2013-01-01

We report on a comparative study of the pore growth during anodization of a narrow-bandgap III-V compound (InAs), a medium-bandgap III-V one (InP) and wide-bandgap II-VI semiconductors (ZnSe and Zn 0,4 Cd 0,6 S). According to the obtained results, the morphology of the porous layers can be controlled by the composition of the electrolyte and the applied electrochemical parameters. It was evidenced that in the narrow bandgap semiconductor InAs it is difficult to control the mechanism of pore growth. Both current line oriented pores and crystallographically oriented pores were produced in the medium-bandgap material InP. The electrochemical nanostructuring of wide-bandgap semiconductors realized in single crystalline high conductivity samples evidenced only current-line oriented pores. This behavior is explained in terms of difference in the values of electronegativity of the constituent atoms and the degree of ionicity. (authors)

Direct Identification of Atomic-Like Electronic Levels in InAs Nano crystal Quantum Dots

International Nuclear Information System (INIS)

Millo, O.; Katz, D.

1999-01-01

The size dependent level structure of InAs nano crystals in the range 2-7 nm in diameter is investigated using both tunneling and optical spectroscopies. The tunneling measurements are performed using a cryogenic scanning tunneling microscope on individual nano crystals that, are attached to a gold substrate via dithiol molecules. The tunneling I-V characteristics manifest an interplay between single electron charging and quantum size effects. We are able to directly identify quantum confined states of isolated InAs nano crystals having s and p symmetries. These states are observed in the I-V curves as two and six-fold single electron charging multiplets. Excellent agreement is found between the strongly allowed optical transitions [1] and the spacing of levels detected in the tunneling experiment. This correlation provides new information on the quantum-dot level structure, from which we conclude that the top-most valence band state has both s and p characteristics. The interplay between level structure singles electron charging of the nano crystals obeys an atomic-like Aufbau sequential electron level occupation

Formation of anodic layers on InAs (111)III. Study of the chemical composition

Energy Technology Data Exchange (ETDEWEB)

Valisheva, N. A., E-mail: valisheva@thermo.isp.nsc.ru; Tereshchenko, O. E. [Russian Academy of Sciences, Institute of Semiconductor Physics, Siberian Branch (Russian Federation); Prosvirin, I. P.; Kalinkin, A. V. [Russian Academy of Sciences, Boreskov Institute of Catalysis, Siberian Branch (Russian Federation); Goljashov, V. A. [Novosibirsk State University (Russian Federation); Levtzova, T. A. [Russian Academy of Sciences, Institute of Semiconductor Physics, Siberian Branch (Russian Federation); Bukhtiyarov, V. I. [Russian Academy of Sciences, Boreskov Institute of Catalysis, Siberian Branch (Russian Federation)

2012-04-15

The chemical composition of {approx}20-nm-thick anodic layers grown on InAs (111)III in alkaline and acid electrolytes containing or not containing NH{sub 4}F is studied by X-ray photoelectron spectroscopy. It is shown that the composition of fluorinated layers is controlled by the relation between the concentrations of fluorine and hydroxide ions in the electrolyte and by diffusion processes in the growing layer. Fluorine accumulates at the (anodic layer)/InAs interface. Oxidation of InAs in an acid electrolyte with a low oxygen content and a high NH{sub 4}F content brings about the formation of anodic layers with a high content of fluorine and elemental arsenic and the formation of an oxygen-free InF{sub x}/InAs interface. Fluorinated layers grown in an alkaline electrolyte with a high content of O{sup 2-} and/or OH{sup -} groups contain approximately three times less fluorine and consist of indium and arsenic oxyfluorides. No distinction between the compositions of the layers grown in both types of fluorine-free electrolytes is established.

Photoreflectance study of InAs ultrathin layer embedded in Si-delta-doped GaAs/AlGaAs quantum wells

Energy Technology Data Exchange (ETDEWEB)

Dhifallah, I., E-mail: ines.dhifallah@gmail.co [Laboratoire de Photovoltaique, des Semiconducteurs et des Nanostructures, Centre de Recherche et des Technologies de l' energie, BP 95 Hammam-Lif 2050 (Tunisia); Daoudi, M.; Bardaoui, A. [Laboratoire de Photovoltaique, des Semiconducteurs et des Nanostructures, Centre de Recherche et des Technologies de l' energie, BP 95 Hammam-Lif 2050 (Tunisia); Eljani, B. [Unite de recherche sur les Hetero-Epitaxie et Applications, Faculte des Sciences de Monastir (Tunisia); Ouerghi, A. [Laboratoire de Photonique et de Nanostructures, CNRS Route de Nozay 91 46a0, Marcoussis (France); Chtourou, R. [Laboratoire de Photovoltaique, des Semiconducteurs et des Nanostructures, Centre de Recherche et des Technologies de l' energie, BP 95 Hammam-Lif 2050 (Tunisia)

2011-05-15

Photoreflectance and photoluminescence studies were performed to characterize InAs ultrathin layer embedded in Si-delta-doped GaAs/AlGaAs high electron mobility transistors. These structures were grown by Molecular Beam Epitaxy on (1 0 0) oriented GaAs substrates with different silicon-delta-doped layer densities. Interband energy transitions in the InAs ultrathin layer quantum well were observed below the GaAs band gap in the photoreflectance spectra, and assigned to electron-heavy-hole (E{sub e-hh}) and electron-light-hole (E{sub e-lh}) fundamental transitions. These transitions were shifted to lower energy with increasing silicon-{delta}-doping density. This effect is in good agreement with our theoretical results based on a self-consistent solution of the coupled Schroedinger and Poisson equations and was explained by increased escape of photogenerated carriers and enhanced Quantum Confined Stark Effect in the Si-delta-doped InAs/GaAs QW. In the photoreflectance spectra, not only the channel well interband energy transitions were observed, but also features associated with the GaAs and AlGaAs bulk layers located at about 1.427 and 1.8 eV, respectively. By analyzing the Franz-Keldysh Oscillations observed in the spectral characteristics of Si-{delta}-doped samples, we have determined the internal electric field introduced by ionized Si-{delta}-doped centers. We have observed an increase in the electric field in the InAs ultrathin layer with increasing silicon content. The results are explained in terms of doping dependent ionized impurities densities and surface charges. - Research highlights: {yields} Studying HEMTs structures with different silicon doping content. {yields} An increase of the electric field in the InAs layer with increasing Si content. {yields} The interband energy transitions in the HEMTs structures have been obtained from PR. {yields} Experimental and theoretical values of transitions energies were in good agreement.

Photoreflectance study of InAs ultrathin layer embedded in Si-delta-doped GaAs/AlGaAs quantum wells

International Nuclear Information System (INIS)

Dhifallah, I.; Daoudi, M.; Bardaoui, A.; Eljani, B.; Ouerghi, A.; Chtourou, R.

2011-01-01

Photoreflectance and photoluminescence studies were performed to characterize InAs ultrathin layer embedded in Si-delta-doped GaAs/AlGaAs high electron mobility transistors. These structures were grown by Molecular Beam Epitaxy on (1 0 0) oriented GaAs substrates with different silicon-delta-doped layer densities. Interband energy transitions in the InAs ultrathin layer quantum well were observed below the GaAs band gap in the photoreflectance spectra, and assigned to electron-heavy-hole (E e-hh ) and electron-light-hole (E e-lh ) fundamental transitions. These transitions were shifted to lower energy with increasing silicon-δ-doping density. This effect is in good agreement with our theoretical results based on a self-consistent solution of the coupled Schroedinger and Poisson equations and was explained by increased escape of photogenerated carriers and enhanced Quantum Confined Stark Effect in the Si-delta-doped InAs/GaAs QW. In the photoreflectance spectra, not only the channel well interband energy transitions were observed, but also features associated with the GaAs and AlGaAs bulk layers located at about 1.427 and 1.8 eV, respectively. By analyzing the Franz-Keldysh Oscillations observed in the spectral characteristics of Si-δ-doped samples, we have determined the internal electric field introduced by ionized Si-δ-doped centers. We have observed an increase in the electric field in the InAs ultrathin layer with increasing silicon content. The results are explained in terms of doping dependent ionized impurities densities and surface charges. - Research highlights: → Studying HEMTs structures with different silicon doping content. → An increase of the electric field in the InAs layer with increasing Si content. → The interband energy transitions in the HEMTs structures have been obtained from PR. → Experimental and theoretical values of transitions energies were in good agreement.

Liquid phase epitaxy of abrupt junctions in InAs and studies of injection radiative tunneling processes

International Nuclear Information System (INIS)

Bull, D.J.

1977-01-01

The p-n junction in a InAs crystal, by liquid phase epitaxy is obtained. The processes of injection and tunneling radiative recombination by emitted radiation from active region of p-n junction for low injection current are studied. (M.C.K.) [pt

Atomic structures of a monolayer of AlAs, GaAs, and InAs on Si(111)

International Nuclear Information System (INIS)

Lee, Geunjung; Yoon, Younggui

2010-01-01

We study atomic structures of a monolayer of AlAs, GaAs, and InAs on a Si(111) substrate from first-principles. The surface with the stacking sequence of ...SiSiMAsSiAs is energetically more stable than the surface with the stacking sequence of ...SiSiSiAsMAs, where M is Al, Ga, or In. The atomic structure of the three top layers of the low-energy surfaces are quite robust, irrespective of M, and the atomic structure of the AlAsSiAs terminated surface and that of the GaAsSiAs terminated surface are very similar. For the high-energy AsMAs terminated surfaces, the broken local tetrahedral symmetry plays an important role in the atomic structures. The calculated atomic structures of InAs on the Si(111) substrate depart most from the structure of crystalline Si.

Seeded growth of InP and InAs quantum rods using indium acetate and myristic acid

International Nuclear Information System (INIS)

Shweky, Itzhak; Aharoni, Assaf; Mokari, Taleb; Rothenberg, Eli; Nadler, Moshe; Popov, Inna; Banin, Uri

2006-01-01

A synthesis of soluble III-V semiconductor quantum rods using gold nanoparticles to direct and catalyze one-dimensional growth is developed. The growth takes place via the solution-liquid-solid (SLS) mechanism where proper precursors are injected into a coordinating solvent. We report the synthesis of InP nanorods using indium acetate and myristic acid with gold nanoparticles as the catalysts in the SLS growth mode. A similar route was successfully developed for the growth of InAs nanorods. We find that the amount of Au catalyst in the reaction is an important parameter to achieve shape control. Transmission electron microscope (TEM) images of InP and InAs nanocrystals revealed that the crystals are mostly rod-shaped, and provide strong evidence for Au presence in one edge. The rods were characterized structurally using X-ray diffraction and high-resolution TEM and optically by absorption and photoluminescence

Nuclear power generation and nuclear non-proliferation

International Nuclear Information System (INIS)

Rathjens, G.

1979-01-01

The main points existing between nuclear energy development and nuclear non-proliferation policy are reviewed. The solar energy and other energy will replace for nuclear fission energy in the twenty first century, but it may not occur in the first half, and the structure has to be established to continue the development of nuclear fission technology, including breeder reactor technology. In the near future, it should be encouraged to use advanced thermal reactors if they are economic and operated with safety. Miserable results may be created in the worldwide scale, if a serious accident occurs anywhere or nuclear power reactors are utilized for military object. It is estimated to be possible to develop the ability of manufacturing nuclear weapons within two or three years in the countries where the industry is highly developed so as to generate nuclear power. It is also difficult to take measures so that nuclear power generation does not increase nuclear proliferation problems, and it is necessary to mitigate the motive and to establish the international organization. Concensus exists that as the minimum security action, the storage and transportation of materials, which can be directly utilized for nuclear weapons, should be decided by the international system. The most portions of sensitive nuclear fuel cycle should be put under the international management, as far as possible. This problem is discussed in INFCE. Related to the nuclear nonproliferation, the difference of policy in fuel cycle problems between USA and the other countries, the enrichment of nuclear fuel material, especially the reasons to inhibit the construction of additional enrichment facilities, nuclear fuel reprocessing problems, radioactive waste disposal, plutonium stock and plutonium recycle problems are reviewed. (Nakai, Y.)

The non-proliferation regime, vertical proliferation and the interests of the Federal Republic of Germany

International Nuclear Information System (INIS)

Fischer, W.

1988-12-01

The disarmament orientation of the NPT, which stands beside the central aim of avoiding horizontal proliferation, raises a question: Does a compatibility exist between the non-proliferation policy of the Federal Republic and its security policy, which has its basic pillar in the nuclear deterrence strategy? Critics of this deterrence policy therefore, hinting to the disarmament determination of the NPT, demand that the Federal Republic should exercise its influence for the conclusion of a 'Comprehensive Test Ban Treaty' (CTBT), the establishment of a 'Nuclear-Weapons-Free-Zones' (NWFZ) in Europe, a 'No First Use'-Treaty (NFU) and finally the abolishment of all atomic weapons ('Zero Solution'). According to them such disarmament 'remedies' can reestablish or assure the waning or damaged international consensus for horizontal non-proliferation. This is a contribution for the establishment of a stable world order and will smooth the way for a prolongation of the NPT in the year 1995. An analysis of the history and the structure of interests shows that the policy of the Federal Republic of Germany is deeply rooted in the NPT and that a prolongation of the treaty and its own membership is a substantial object of the foreign and security policy. Consequently the Federal Republic has to face the demands for an intensification of 'anti-nuclear measures' and has to examine their acceptability and their usefulness with respect to non-proliferation. The structure of the problem encloses the following aspects: The security conception of the Federal Republic with its military-strategic essence; the provisions in article VI NPT for negotiations with the object of a world free of atomic weapons; the derived disarmament 'remedies' for strengthening the consensus for horizontal non-proliferation and, finally, the real interface between horizontal and vertical proliferation. (orig./DG) [de

Problems of the nuclear non-proliferation policy. Contributions to the international discussion

International Nuclear Information System (INIS)

Blix, H.; Butler, P. von; Fischer, W.; Caccia Dominioni, F.; Frick, H.; Gmelin, W.; Haeckel, E.; Lauppe, W.D.; Mueller, H.; Richter, B.; Stein, G.

1994-01-01

The volume assembles a number of essays wherein basic problems of nonproliferation are identified and discussed in view of recent developments and future policy requirements. What is the role of multilateral institutions in the containment of nuclear proliferation? How are Western Europe's security needs to be reconciled with the tenets of the global nonproliferation regime? How can international safeguards be upgraded so as to increase confidence among states? What kinds of disciplinary instruments are needed for the international community to prevent an unco-operative state from gaining access to nuclear weapons? What kinds of obstacles stand in the way of smooth co-operation between the European Union and the United States in the nuclear field? How does the demise of global bipolarity impinge on the need to pursue an international nuclear order? The essays in this volume seek to combine structural analysis of conceptual issues with substantive policy recommendations. (orig./HP) [de

Impasses and mistakes of the nuclear non-proliferation policy

International Nuclear Information System (INIS)

Hirst, M.

1980-01-01

It is analyzed the limitations for implementing the American Nuclear non-proliferation policy. It is shown the crisis of the North American international relations, with the economic and scientific development of the advanced capitalist nations and some countries of the third world, the penetration of these countries in the world trade commerce of the nuclear industry as sellers and cunsumers, and the Latin American's and Brazil's position in the international panorama of nuclear power. (M.C.K.) [pt

Non-proliferation and international safeguards

International Nuclear Information System (INIS)

Blix, H.

1992-01-01

Full text: In my view, drastic nuclear disarmament by nuclear weapon States could be coupled with universal commitment to non-proliferation by non-nuclear weapon States by 1995 when the extension of the NPT Will be discussed. The incentives and disincentives for making and stockpiling nuclear weapons are first of all in the political and security fields, (Global and regional detente reduce the incentive, With the cold war gone, the US and Russia are now agreeing on far-reaching cuts in their nuclear arsenals and at some point the other declared nuclear weapon States Will follow.In the regional fields, we have seen how Argentina and Brazil are about to commit themselves to exclusively peaceful uses of the atom through the Latin American Tlatelolco Treaty. And we have seen how South Africa has joined the NPT. A new wave of States adhering to the NPT may be expected from countries in the former Soviet Union. Some have already come, others are on the way. Detente in the Middle East and on the Indian subcontinent would improve the outlook for non-proliferation in these areas. A second barrier to nuclear proliferation lies in export restrictions on sensitive nuclear material and equipment, Following the discoveries in Iraq, these restrictions are being strengthened in a large number of States. A third barrier to nuclear proliferation lies in the economic and political consequences that would follow for a State if IAEA safeguards inspection revealed activities aimed at the production of nuclear weapons. These must have a high degree of reliability. The case of Iraq showed that it was possible for a closed, highly militarized State to hide nuclear activities from the IAEA and the world We are now drawing the lessons from this case. It is not physically possible for inspectors to look into every building and basement in vast countries, They must have information about where to look, and the IAEA is significantly strengthening its information basis. The IAEA has also re

Fukushima Daiichi: implications for carbon-free energy, nuclear nonproliferation, and community resilience.

Science.gov (United States)

Hall, Howard L

2011-07-01

Implications of the nuclear power plant accidents at Fukushima Daiichi are explored in this commentary. In addition to questions of nuclear reactor regulatory standards, broader implications on noncarbon-emitting energy production, nuclear nonproliferation objectives, and community resilience and emergency response against catastrophic events are explored. Copyright © 2011 SETAC.

Nonproliferation and arms control assessment of weapons-usable fissile material storage and excess plutonium disposition alternatives

International Nuclear Information System (INIS)

1997-01-01

This report has been prepared by the Department of Energy's Office of Arms Control and Nonproliferation (DOE-NN) with support from the Office of Fissile Materials Disposition (DOE-MD). Its purpose is to analyze the nonproliferation and arms reduction implications of the alternatives for storage of plutonium and HEU, and disposition of excess plutonium, to aid policymakers and the public in making final decisions. While this assessment describes the benefits and risks associated with each option, it does not attempt to rank order the options or choose which ones are best. It does, however, identify steps which could maximize the benefits and mitigate any vulnerabilities of the various alternatives under consideration

Growth of InAs Wurtzite Nanocrosses from Hexagonal and Cubic Basis

DEFF Research Database (Denmark)

Krizek, Filip; Kanne, Thomas; Razmadze, Davydas

2017-01-01

. Two methods use conventional wurtzite nanowire arrays as a 6-fold hexagonal basis for growing single crystal wurtzite nanocrosses. A third method uses the 2-fold cubic symmetry of (100) substrates to form well-defined coherent inclusions of zinc blende in the center of the nanocrosses. We show......Epitaxially connected nanowires allow for the design of electron transport experiments and applications beyond the standard two terminal device geometries. In this Letter, we present growth methods of three distinct types of wurtzite structured InAs nanocrosses via the vapor-liquid-solid mechanism...

Leveraging U.S. nuclear weapons policy to advance U.S. nonproliferation goals : implications of major theories of international relations.

Energy Technology Data Exchange (ETDEWEB)

Walter, Andrew

2009-06-01

National policymakers are currently considering a dilemma of critical importance to the continued security of the United States: how can U.S. nuclear weapons policies be leveraged to benefit U.S. nuclear nonproliferation goals in the near-term, without sacrificing U.S. national security? In its role supporting U.S. nuclear weapons policy, Sandia National Laboratories has a responsibility to provide objective technical advice to support policy deliberations on this question. However, to best fulfill this duty Sandia must have a broader understanding of the context of the problem. To help develop this understanding, this paper analyzes the two predominant analytical perspectives of international relations theory to explore their prescriptions for how nuclear weapons and nonproliferation policies interact. As lenses with which to view and make sense of the world, theories of international relations must play a crucial role in framing the trade-offs at the intersection of the nuclear weapons and nonproliferation policy domains. An analysis of what these theories suggest as courses of action to leverage nuclear weapons policies to benefit nonproliferation goals is then offered, with particular emphasis on where the policy prescriptions resulting from the respective theories align to offer near-term policy changes with broad theoretical support. These policy prescriptions are then compared to the 2001 Nuclear Posture Review to understand what the theories indicate policymakers may have gotten right in their dealing with the nuclear dilemma, and where they may have gone wrong. Finally, a brief international relations research agenda is proposed to help address the dilemma between nuclear deterrence and nuclear nonproliferation policies, with particular emphasis on how such an agenda can best support the needs of the policy community and a potential 'all things nuclear' policy deliberation and decision-support framework.

Comparison of the reactivity of alkyl and alkyl amine precursors with native oxide GaAs(100) and InAs(100) surfaces

Energy Technology Data Exchange (ETDEWEB)

Henegar, A.J., E-mail: henegar1@umbc.edu; Gougousi, T., E-mail: gougousi@umbc.edu

2016-12-30

Graphical abstract: The interaction of the native oxides of GaAs(100) and InAs(100) with alkyl (trimethyl aluminum) and alkyl amine (tetrakis dimethylamino titanium) precursors during thermal atomic layer deposition (ALD) of Al{sub 2}O{sub 3} and TiO{sub 2} is compared. Al{sub 2}O{sub 3} if found to be a significantly better barrier against the transport of the surface native oxide during the film deposition as well as after post-deposition heat treatment. This superior blocking ability also limits the removal of the native oxides during the Al{sub 2}O{sub 3} ALD process. - Highlights: • Native oxide diffusion is required for continuous native oxide removal. • The diffusion barrier capabilities of Al{sub 2}O{sub 3} limits native oxide removal during ALD. • Arsenic oxide exhibits higher mobility from InAs compared to GaAs substrates. • Oxygen scavenging from the surface by trimethyl aluminum is confirmed. - Abstract: In this manuscript we compare the interaction of alkyl (trimethyl aluminum) and alkyl amine (tetrakis dimethylamino titanium) precursors during thermal atomic layer deposition with III-V native oxides. For that purpose we deposit Al{sub 2}O{sub 3} and TiO{sub 2}, using H{sub 2}O as the oxidizer, on GaAs(100) and InAs(100) native oxide surfaces. We find that there are distinct differences in the behavior of the two films. For the Al{sub 2}O{sub 3} ALD very little native oxide removal happens after the first few ALD cycles while the interaction of the alkyl amine precursor for TiO{sub 2} and the native oxides continues well after the surface has been covered with 2 nm of TiO{sub 2}. This difference is traced to the superior properties of Al{sub 2}O{sub 3} as a diffusion barrier. Differences are also found in the behavior of the arsenic oxides of the InAs and GaAs substrates. The arsenic oxides from the InAs surface are found to mix more efficiently in the growing dielectric film than those from the GaAs surface. This difference is attributed to

Comparison of the reactivity of alkyl and alkyl amine precursors with native oxide GaAs(100) and InAs(100) surfaces

International Nuclear Information System (INIS)

Henegar, A.J.; Gougousi, T.

2016-01-01

Graphical abstract: The interaction of the native oxides of GaAs(100) and InAs(100) with alkyl (trimethyl aluminum) and alkyl amine (tetrakis dimethylamino titanium) precursors during thermal atomic layer deposition (ALD) of Al_2O_3 and TiO_2 is compared. Al_2O_3 if found to be a significantly better barrier against the transport of the surface native oxide during the film deposition as well as after post-deposition heat treatment. This superior blocking ability also limits the removal of the native oxides during the Al_2O_3 ALD process. - Highlights: • Native oxide diffusion is required for continuous native oxide removal. • The diffusion barrier capabilities of Al_2O_3 limits native oxide removal during ALD. • Arsenic oxide exhibits higher mobility from InAs compared to GaAs substrates. • Oxygen scavenging from the surface by trimethyl aluminum is confirmed. - Abstract: In this manuscript we compare the interaction of alkyl (trimethyl aluminum) and alkyl amine (tetrakis dimethylamino titanium) precursors during thermal atomic layer deposition with III-V native oxides. For that purpose we deposit Al_2O_3 and TiO_2, using H_2O as the oxidizer, on GaAs(100) and InAs(100) native oxide surfaces. We find that there are distinct differences in the behavior of the two films. For the Al_2O_3 ALD very little native oxide removal happens after the first few ALD cycles while the interaction of the alkyl amine precursor for TiO_2 and the native oxides continues well after the surface has been covered with 2 nm of TiO_2. This difference is traced to the superior properties of Al_2O_3 as a diffusion barrier. Differences are also found in the behavior of the arsenic oxides of the InAs and GaAs substrates. The arsenic oxides from the InAs surface are found to mix more efficiently in the growing dielectric film than those from the GaAs surface. This difference is attributed to lower native oxide stability as well as an initial diffusion path formation by the indium oxides.

Self-assembled monolayers of alkyl-thiols on InAs: A Kelvin probe force microscopy study

Science.gov (United States)

Szwajca, A.; Wei, J.; Schukfeh, M. I.; Tornow, M.

2015-03-01

We report on the preparation and characterization of self-assembled monolayers from aliphatic thiols with different chain length and termination on InAs (100) planar surfaces. This included as first step the development and investigation of a thorough chemical InAs surface preparation step using a dedicated bromine/NH4OH-based etching process. Ellipsometry, contact angle measurements and atomic force microscopy (AFM) indicated the formation of smooth, surface conforming monolayers. The molecular tilt angles were obtained as 30 ± 10° with respect to the surface normal. Kelvin probe force microscopy (KPFM) measurements in hand with Parameterized Model number 5 (PM5) calculations of the involved molecular dipoles allowed for an estimation of the molecular packing densities on the surface. We obtained values of up to n = 1014 cm- 2 for the SAMs under study. These are close to what is predicted from a simple geometrical model that would calculate a maximum density of about n = 2.7 × 1014 cm- 2. We take this as additional conformation of the substrate smoothness and quality of our InAs-SAM hybrid layer systems.

IAEA Director General welcomes Cuba's intention to join the nuclear Non-Proliferation Treaty

International Nuclear Information System (INIS)

2002-01-01

Full text: IAEA Director General Mohamed ElBaradei welcomed Cuba's announcement to accede to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) and to ratify the Treaty of Tlatelolco establishing a nuclear-weapon-free zone in Latin America and the Caribbean. He expressed the hope that Cuba will conclude soon a comprehensive safeguards agreement with the Agency, as required under Article III of the NPT. 'With Cuba's intention to become party to the NPT, we have come a step closer to a universal nuclear non-proliferation regime,' Mr. ElBaradei said. Only three countries worldwide with significant nuclear activities now remain outside the NPT. With 188 countries party to the Treaty, the NPT is the most adhered to international agreement after the United Nations Charter and the most widely adhered to multilateral arms control treaty. The NPT makes it mandatory that all non-nuclear-weapon States conclude comprehensive safeguards agreements with the IAEA, and thus put all of their nuclear material under IAEA safeguards. The Director General also welcomed Cuba's ratification of the Tlatelolco Treaty, which completes the process of having all countries in the region of Latin America and the Caribbean as members of the nuclear-weapon-free zone in that region. Mr. ElBaradei said that, 'the Tlatelolco Treaty provides a good model for other regional nuclear-weapon-free zones to follow'. He added that 'universal adherence of all countries in regions having nuclear-weapon-free zone arrangements is important to further strengthen the non-proliferation regime'. (IAEA)

Strain in GaAs / InAs core-shell nanowire heterostructures grown on GaAs

Energy Technology Data Exchange (ETDEWEB)

Biermanns, Andreas; Davydok, Anton; Pietsch, Ullrich [Universitaet Siegen, Festkoerperphysik (Germany); Rieger, Torsten; Lepsa, Mihail Ion [Peter Gruenberg Institut 9, Forschungszentrum Juelich (Germany); JARA - Fundamentals of Future Information Technology (Germany)

2012-07-01

The growth of semiconductor nanowires (NWs) has attracted significant interest in recent years due to the possible fabrication of novel semiconductor devices for future electronic and opto-electronic applications. Compared to planar heterostructures, the nanowire approach offers an advantage regarding the possibility to form heterostructures between highly lattice mismatched systems, because the free surface of the nanowires allows to relieve the strain more efficiently. One particular way to form heterostructures in the NW geometry, is the fabrication of core-shell devices, in which a NW core is surrounded by a shell of different material. The understanding of the mutual strain between core and shell, as well as the relaxation behavior of the system are crucial for the fabrication of functional devices. In this contribution we report on first X-ray diffraction measurements of GaAs-core/InAs-shell nanowires grown on GaAs(111) by molecular beam epitaxy. Using symmetric- and grazing-incidence X-ray diffraction, the relaxation state of the InAs shell as well as the strain in the GaAs core are measured as function of the InAs shell thickness, showing a gradual relaxation behavior of the shell.

Nuclear disarmament and evolution of the nuclear non-proliferation regime

International Nuclear Information System (INIS)

Bragin, V.; Carlson, J.; Bardsley, J.; Hill, J.

1999-01-01

The 1995 NPT Review and Extension Conference reaffirmed 'the ultimate goals of the complete elimination of nuclear weapons and a treaty on general and complete disarmament under strict and effective international control' and endorsed 'universal application of safeguards once the complete elimination of nuclear weapons has been achieved'. Hence strengthening the international non-proliferation regime and incremental broadening of its coverage towards the universal application of international safeguards in all States is a high priority albeit for the medium to long term. A tentative attempt is made in this paper to anticipate how the elements of verification under the NPT, FMCT and other conventions and arrangements related to nuclear non-proliferation will evolve against the background of the disarmament process, with the goal of achieving at some future stage an ultimate convergence of verification regimes under a complete nuclear disarmament. We think, however, that most of the new initiatives in the area of disarmament/non-proliferation should be realised during the current disarmament phase. We do not wish our model to be perceived as a rigid time-bound scheme. New initiatives should be implemented in parallel and as soon as practicable. This paper reflects the personal views of the authors and should not be taken to represent Australian Government policy. (author)

Critical Temperature for the Conversion from Wurtzite to Zincblende of the Optical Emission of InAs Nanowires

KAUST Repository

Rota, Michele B.; Ameruddin, Amira S.; Wong-Leung, Jennifer; Belabbes, Abderrezak; Gao, Qiang; Miriametro, Antonio; Mura, Francesco; Tan, Hark Hoe; Polimeni, Antonio; Bechstedt, Friedhelm; Jagadish, Chennupati; Capizzi, Mario

2017-01-01

One hour annealing at 300 degrees C changes the optical emission characteristics of InAs nanowires (NWs) from the wurtzite (WZ) phase into that of zincblende (ZB). These results are accounted for by the conversion of a small fraction of the NW WZ

InAs quantum dot growth on AlxGa1−xAs by metalorganic vapor phase epitaxy for intermediate band solar cells

International Nuclear Information System (INIS)

Jakomin, R.; Kawabata, R. M. S.; Souza, P. L.; Mourão, R. T.; Pires, M. P.; Micha, D. N.; Xie, H.; Fischer, A. M.; Ponce, F. A.

2014-01-01

InAs quantum dot multilayers have been grown using Al x Ga 1−x As spacers with dimensions and compositions near the theoretical values for optimized efficiencies in intermediate band photovoltaic cells. Using an aluminium composition of x = 0.3 and InAs dot vertical dimensions of 5 nm, transitions to an intermediate band with energy close to the ideal theoretical value have been obtained. Optimum size uniformity and density have been achieved by capping the quantum dots with GaAs following the indium-flush method. This approach has also resulted in minimization of crystalline defects in the epilayer structure

Formation of InAs/GaAs quantum dots from a subcritical InAs wetting layer: A reflection high-energy electron diffraction and theoretical study

International Nuclear Information System (INIS)

Song, H. Z.; Usuki, T.; Nakata, Y.; Yokoyama, N.; Sasakura, H.; Muto, S.

2006-01-01

InAs/GaAs quantum dots (QD's) are formed by postgrowth annealing of an InAs wetting layer thinner than the critical thickness for the transition from two- (2D) to three-dimensional (3D) growth mode. Reflection high energy electron diffraction is used to monitor the QD formation. Based on a mean-field theory [Phys. Rev. Lett. 79, 897 (1997)], the time evolution of total QD's volume, first increasing and finally saturating, is well explained by precursors forming during wetting layer growth and converting into nucleated QD's after growth stop. Both the saturation QD's volume and the QD nucleation rate depend exponentially on the InAs coverage. These behaviors and their temperature and InAs growth rate dependences are essentially understandable in the frame of the mean-field theory. Similar analysis to conventional QD growth suggests that the often observed significant mass transport from wetting layer to QD's can be ascribed to the precursors existing before 2D-3D growth mode transition

Nuclear power and the non-proliferation issue

International Nuclear Information System (INIS)

1978-12-01

This leaflet, issued by the British Nuclear Forum on behalf of the industry, seeks first to place the problem of reconciling the need for nuclear power with its possible weapon uses in a historical perspective. Secondly, it describes the technical and political measures which are now taken, and others which could be introduced in order to ensure that nuclear power, which offers the cheapest and safest large-scale energy source for the future, can be made available without contributing to the proliferation of nuclear weapons. Headings are: introduction; the early years; the IAEA; uranium enrichment; plutonium; secrecy has failed; the Non-Proliferation Treaty; the London Suppliers Group; the situation today; the British position; conclusions. (U.K.)

Steering of quantum waves: Demonstration of Y-junction transistors using InAs quantum wires

Science.gov (United States)

Jones, Gregory M.; Qin, Jie; Yang, Chia-Hung; Yang, Ming-Jey

2005-06-01

In this paper we demonstrate using an InAs quantum wire Y-branch switch that the electron wave can be switched to exit from the two drains by a lateral gate bias. The gating modifies the electron wave functions as well as their interference pattern, causing the anti-correlated, oscillatory transconductances. Our result suggests a new transistor function in a multiple-lead ballistic quantum wire system.

Multinational alternatives and nuclear nonproliferation

International Nuclear Information System (INIS)

Scheinman, L.

1981-01-01

The use of multinational institutional arrangements to control sensitive nuclear-fuel-cycle activities has interested policymakers since the dawn of the nuclear age. Several such ventures have been tried in the past, largely for economic, commercial, or technical reasons, and they have enjoyed varying degrees of success. More recently, with the spread of sensitive nuclear technologies, multinational arrangements have received increasing attention as a means of reinforcing international safeguards which, together with political commitments on peaceful use, have been the principal components of the nonproliferation regime. The political acceptability and efficacy of multinational arrangements is related to the historic experience with multinational ventures, the changed political circumstances of the 1970s, and the probable requirements for constructive future cooperation. As part of a comprehensive regime covering the development of sensitive nuclear activities, multinational arrangements can reinforce the regime in a manner that is widely acceptable. A political effort to win support for such arrangements is thus worthwhile. 29 references

Report of 'the 2014 international forum on peaceful use of nuclear energy, nuclear non-proliferation and nuclear security. Future direction toward promoting non-proliferation and the ideal method of developing human resources using Centers of Excellence (COEs) following the new strategic energy plan'

International Nuclear Information System (INIS)

Yamaga, Chikanobu; Tomikawa, Hirofumi; Kobayashi, Naoki; Naoi, Yosuke; Oda, Tetsuzo; Mochiji, Toshiro

2015-10-01

The Japan Atomic Energy Agency (JAEA) held 'International Forum on Peaceful Use of Nuclear Energy, Nuclear Non-proliferation and Nuclear Security – Future direction toward promoting non-proliferation and the ideal method of developing human resources using Centers of Excellence (COEs) following the New Strategic Energy Plan -' on 3 December 2014, with the Japan Institute of International Affairs (JIIA) and School of Engineering, The University of Tokyo, and International Nuclear Research Center, Tokyo Institute of Technology as co-hosts. In the Forum, officials and experts from Japan, the United States explained their efforts regarding peaceful use of nuclear energy, nuclear non-proliferation and nuclear security. Discussion was made in two panels, entitled 'Effective and efficient measures to ensure nuclear non-proliferation based on domestic and foreign issues and the direction and role of technology development' and 'Roles of nuclear security COEs and future expectations'. In Panel Discussion 1, as the nuclear non-proliferation regime is facing various problems and challenges under current international circumstances, how to implement effective and efficient safeguards was discussed. In Panel Discussion 2, panelists discussed the following three points: 1. Current status of Nuclear Security Training and Support Centers and COEs, and Good Practice; 2. What these centers can do to enhance nuclear security (New role for COEs); 3. Regional cooperation in the Nuclear Security Training and Support Center (NSSC) and COEs in states, which the IAEA recommends establishing, and international cooperation and partnerships with international initiatives (New Role). Officials and experts from Japan, IAEA, the United States, France, Republic of Korea, and Indonesia participated in the panel and made contributions to active discussion. This report includes abstracts of keynote speeches, summaries of two panel discussions and materials of the

Abstracts of reports of the International conference on non-proliferation problems

International Nuclear Information System (INIS)

Koltysheva, G.I.; Perepelkin, I.G.

1997-01-01

On August 21, 1947, the USSR Council of Ministers made a decision on creating Semipalatinsk Nuclear Test Site (STS). The first Nuclear Test on the Test Site was conducted on August 29, 1949, the last one was made on October 19, 1989. In all during 40 years on Semipalatinsk Test Site 116 ground and air and 340 underground nuclear tests were conducted. They brought much damage to health and lives of thousands of people who involuntarily participated in those events. On August 29, 1991, by Kazakstan President's decree STS was closed but the problems of people's rehabilitation, natural landscapes recovering, test-site infrastructure conversion remained. These problems are being solved under direct state programs, intergovernmental agreements of Kazakstan with Russia and the USA, cooperation with different international and foreign organizations, enterprises, scientific-research centers. Kazakstan subsequently constantly pursues the policy of nonproliferation, takes measures on ellimination of nuclear tests consequences and relative infrastructure. The Republic is not involved into military nuclear programs. From its territory all the nuclear weapon was taken away. Kazakstan joined the Agreement on Non-proliferation, signed the Agreement on Safeguards to all Nuclear activity on Kazakh territory with the IAEA

Nonproliferation and arms control assessment of weapons-usable fissile material storage and excess plutonium disposition alternatives

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-01-01

This report has been prepared by the Department of Energy`s Office of Arms Control and Nonproliferation (DOE-NN) with support from the Office of Fissile Materials Disposition (DOE-MD). Its purpose is to analyze the nonproliferation and arms reduction implications of the alternatives for storage of plutonium and HEU, and disposition of excess plutonium, to aid policymakers and the public in making final decisions. While this assessment describes the benefits and risks associated with each option, it does not attempt to rank order the options or choose which ones are best. It does, however, identify steps which could maximize the benefits and mitigate any vulnerabilities of the various alternatives under consideration.

Sweden and the making of nuclear non-proliferation: from indecision to assertiveness

International Nuclear Information System (INIS)

Dassen, L. van

1998-03-01

Swedish research on nuclear weapons started at a modest scale in 1945 but was soon expanded. By the early 1950s the research programme started to face some of the problems that were going to accompany it for the rest of its life: different priorities and cost-estimates were made by the sectors that wanted to develop nuclear energy and those working on the bomb. Moreover, an introduction of nuclear weapons would lead to a major redistribution of resources to the disadvantage of the navy and army. The public and political debates intensified during the 1950s and culminated in 1960. At first, pro-nuclear voices had been strongest but were soon challenged by interest groups, unions and peace movements. 1960, a committee within the government had established a compromise: Nuclear weapons research for production of weapons would be terminated, while research on the consequences of nuclear weapons would continue. It was a cosmetic decision that could cover for a continued research on weapons design. Nevertheless, there are some general qualities from the debates that indicate why the outcome was that Sweden signed the NPT in 1968. First, the number of interested persons, groups movements and party politicians engaged in the issue increased every time the issue came up. Secondly, the segments of society that supported the nuclear option remained roughly the same. No strong movements rallied to the defence of this position. On the other hand, the anti-nuclear wing received more and more followers. Third, there was a marked tendency by virtually all actors (except the military) to include every sign of progress in international disarmament and non-proliferation efforts as arguments against Swedish proliferation. Since 1968, the non-proliferation choice has ben manifested through Sweden''s adherence to the NPT and this has been accompanied by a strong commitment to other non-proliferation initiatives

Non-proliferation issues for the disposition of fissile materials using reactor alternatives

International Nuclear Information System (INIS)

Jaeger, C.D.; Duggan, R.A.; Tolk, K.M.

1996-01-01

The Department of Energy (DOE) is analyzing long-term storage on options for excess weapons-usable fissile materials. A number of the disposition alternatives are being considered which involve the use of reactors. The various reactor alternatives are all very similar and include front-end processes that could convert plutonium to a usable form for fuel fabrication, a MOX fuel fab facility, reactors to bum the MOX fuel and ultimate disposal of spent fuel in some geologic repository. They include existing, partially completed, advanced or evolutionary light water reactors and Canadian deuterium uranium (CANDU) reactors. In addition to the differences in the type of reactors, other variants on these alternatives are being evaluated to include the location and number of the reactors, the location of the mixed oxide (MOX) fabrication facility, the ownership of the facilities (private or government) and the colocation and/or separation of these facilities. All of these alternatives and their variants must be evaluated with respect to non-proliferation resistance. Both domestic and international safeguards support are being provided to DOE's Fissile Materials Disposition Program (FMDP) and includes such areas as physical protection, nuclear materials accountability and material containment and surveillance. This paper will focus on how the non-proliferation objective of reducing security risks and strengthening arms reduction will be accomplished and what some of the nonproliferation issues are for the reactor alternatives. Proliferation risk has been defined in terms of material form, physical environment, and the level of security and safeguards that is applied to the material. Metrics have been developed for each of these factors. The reactor alternatives will be evaluated with respect to these proliferation risk factors at each of the unit process locations in the alternative

Non-proliferation issues for the disposition of fissile materials using reactor alternatives

International Nuclear Information System (INIS)

Jaeger, C.D.; Duggan, R.A.; Tolk, K.M.

1996-01-01

The Department of Energy (DOE) is analyzing long-term storage imposition options for excess weapons-usable fissile materials. A number of the disposition alternatives are being considered which involve the use of reactors. The various reactor alternatives are all very similar and include front-end processes that could convert plutonium to a usable form for fuel fabrication, a MOX fuel fab facility, reactors to burn the MOX fuel and ultimate disposal of spent fuel in some geologic repository. They include existing, partially completed, advanced or evolutionary light water reactors and Canadian deuterium uranium (CANDU) reactors. In addition to the differences in the type of reactors, other variants on these alternatives are being evaluated to include the location and number of the reactors, the location of the mixed oxide (MOX) fabrication facility, the ownership of the facilities (private or government) and the colocation and/or separation of these facilities. All of these alternatives and their variants must be evaluated with respect to non-proliferation resistance. Both domestic and international safeguards support are being provided to DOE's Fissile Materials Disposition Program (FMDP) and includes such areas as physical protection, nuclear materials accountability and material containment and surveillance. This paper will focus on how the non-proliferation objective of reducing security risks and strengthening arms reduction will be accomplished and what some of the non-proliferation issues are for the reactor alternatives. Proliferation risk has been defined in terms of material form, physical environment, and the level of security and safeguards that is applied to the material. Metrics have been developed for each of these factors. The reactor alternatives will be evaluated with respect to these proliferation risk factors at each of the unit process locations in the alternative

Sweden and the making of nuclear non-proliferation: from indecision to assertiveness

Energy Technology Data Exchange (ETDEWEB)

Dassen, L. van [Uppsala Univ. (Sweden). Dept. of Peace and Conflict Research

1998-03-01

Swedish research on nuclear weapons started at a modest scale in 1945 but was soon expanded. By the early 1950s the research programme started to face some of the problems that were going to accompany it for the rest of its life: different priorities and cost-estimates were made by the sectors that wanted to develop nuclear energy and those working on the bomb. Moreover, an introduction of nuclear weapons would lead to a major redistribution of resources to the disadvantage of the navy and army. The public and political debates intensified during the 1950s and culminated in 1960. At first, pro-nuclear voices had been strongest but were soon challenged by interest groups, unions and peace movements. 1960, a committee within the government had established a compromise: Nuclear weapons research for production of weapons would be terminated, while research on the consequences of nuclear weapons would continue. It was a cosmetic decision that could cover for a continued research on weapons design. Nevertheless, there are some general qualities from the debates that indicate why the outcome was that Sweden signed the NPT in 1968. First, the number of interested persons, groups movements and party politicians engaged in the issue increased every time the issue came up. Secondly, the segments of society that supported the nuclear option remained roughly the same. No strong movements rallied to the defence of this position. On the other hand, the anti-nuclear wing received more and more followers. Third, there was a marked tendency by virtually all actors (except the military) to include every sign of progress in international disarmament and non-proliferation efforts as arguments against Swedish proliferation. Since 1968, the non-proliferation choice has ben manifested through Sweden``s adherence to the NPT and this has been accompanied by a strong commitment to other non-proliferation initiatives. Refs.

The control of non-proliferation of nuclear weapons and nuclear development - present uncertainties

International Nuclear Information System (INIS)

Machado de Faria, N.G.; Amaral Barros, E.

1983-01-01

This report gives the views of Brazilian lawyers on the non-proliferation of nuclear weapons. It deals with the present situation and future prospects concerning the uses of nuclear energy. In particular, it proposes the preparation of a protocol prohibiting the use of nuclear weapons. (NEA) [fr

Nuclear energy and non-proliferation in Latin America: the constitution of Tlatelolco system

International Nuclear Information System (INIS)

Armanet, P.

1982-01-01

The nuclear energy as alternative energy resource and its military use are analysed. Then the main characteristics of the Tratelolco treaty and non-proliferation in Latin America are discussed. Finally the importance of the nuclear-weapons-free zone in Latin America is shown. (A.B.T.) [pt

Framework for Proliferation Resistance and Physical Protection for Nonproliferation Impact Assessments

International Nuclear Information System (INIS)

Bari, R.

2008-01-01

This report describes a framework for proliferation resistance and physical protection evaluation for the fuel cycle systems envisioned in the expansion of nuclear power for electricity generation. The methodology is based on an approach developed as part of the Generation IV technical evaluation framework and on a qualitative evaluation approach to policy factors similar to those that were introduced in previous Nonproliferation Impact Assessments performed by DOE

The third order nonlinear susceptibility of InAs at infrared region

International Nuclear Information System (INIS)

Musayev, M.A.

2008-01-01

Nonlinear susceptibilities of the third order and coefficient of nonlinear absorption in InAs n-type with a different degree of a doping have been measured. The values of the third order nonlinear susceptibilities have derived from these measurements essentially exceed the values calculated on the basis of model featuring nonlinear susceptibility of electrons, being in conduction-band nonparabolicity. It has been shown that the observable discrepancy has been eliminated, if in calculation a dissipation of energy of electrons has been considered. Growth of efficiency at four-wave mixingin narrow-gap semiconductors has been restricted to nonlinear absorption of interacting waves

In situ doping of catalyst-free InAs nanowires with Si: Growth, polytypism, and local vibrational modes of Si

Energy Technology Data Exchange (ETDEWEB)

Dimakis, Emmanouil; Ramsteiner, Manfred; Huang, Chang-Ning; Trampert, Achim; Riechert, Henning; Geelhaar, Lutz [Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin (Germany); Davydok, Anton; Biermanns, Andreas; Pietsch, Ullrich [Festkörperphysik, Universität Siegen, Walter-Flex-Str. 3, 57072 Siegen (Germany)

2013-09-30

Growth and structural aspects of the in situ doping of InAs nanowires with Si have been investigated. The nanowires were grown catalyst-free on Si(111) substrates by molecular beam epitaxy. The supply of Si influenced the growth kinetics, affecting the nanowire dimensions, but not the degree of structural polytypism, which was always pronounced. As determined by Raman spectroscopy, Si was incorporated as substitutional impurity exclusively on In sites, which makes it a donor. Previously unknown Si-related Raman peaks at 355 and 360 cm{sup −1} were identified, based on their symmetry properties in polarization-dependent measurements, as the two local vibrational modes of an isolated Si impurity on In site along and perpendicular, respectively, to the c-axis of the wurtzite InAs crystal.

INFLUENCE OF LOW-ENERGY AR-SPUTTERING ON THE ELECTRONIC-PROPERTIES OF INAS-BASED QUANTUM-WELL STRUCTURES

NARCIS (Netherlands)

Magnee, P.H.C.; den Hartog, S.G.; Wees, B.J.van; Klapwijk, T.M; van de Graaf, W.; Borghs, G.

1995-01-01

The influence of low energy (80-500 eV) Ar-ion milling cleaning techniques on InAs based quantum well structures is investigated. It is found that both etching with a Kaufmann source and sputter-etching with a rf-plasma enhances the electron density and reduces the mobility. An anneal at 180 degrees

Swedish support programme on nuclear non-proliferation in Central and Eastern Europe and Central Asia

Energy Technology Data Exchange (ETDEWEB)

Ek, P.; Andersson, Sarmite [Swedish Nuclear Power Inspectorate, Stockholm (Sweden); Wredberg, L. [ILG Consultant Ltd., Vienna (Austria)

2000-06-15

At the request of the Swedish Government, the Swedish Nuclear Power Inspectorate has established a support and co-operation programme in the area of nuclear non-proliferation with Russia and several of the republics of the former Soviet Union. The Programme was initiated in 1991 and an overall goal is to accomplish national means and measures for control and protection of nuclear material and facilities, in order to minimise the risk of proliferation of nuclear weapons and illicit trafficking of nuclear material and equipment. The objective of the Swedish Support Programme is to help each, so called, recipient State to be able to, independently and without help from outside, take the full responsibility for operating a national non-proliferation system and thereby fulfil the requirements imposed through the international legal instruments. This would include both the development and implementation of a modern nuclear legislation system, and the establishment of the components making up a national system for combating illicit trafficking. The support and co-operation projects are organised in five Project Groups (i.e. nuclear legislation, nuclear material control, physical protection, export/import control, and combating of illicit trafficking), which together cover the entire non-proliferation area. Up till June 2000, support and co-operation projects, completed and on-going, have been carried out in ten States, namely Armenia, Azerbaijan, Belarus, Georgia, Kazakstan, Latvia, Lithuania, Moldova, Russia and Ukraine. Furthermore, programmes have been initiated during the first part of 2000 with Estonia, Uzbekistan, Kyrgyzstan and Tajikistan. In addition, assistance has been given to Poland on a specific nuclear material accountancy topic. All projects are done on request by and in co-operation with these States. The total number of projects initiated during the period 1991 to June 2000 is 109, thereof 77 have been completed and 32 are currently on-going. It is the

Swedish support programme on nuclear non-proliferation in Central and Eastern Europe and Central Asia

International Nuclear Information System (INIS)

Ek, P.; Andersson, Sarmite; Wredberg, L.

2000-06-01

At the request of the Swedish Government, the Swedish Nuclear Power Inspectorate has established a support and co-operation programme in the area of nuclear non-proliferation with Russia and several of the republics of the former Soviet Union. The Programme was initiated in 1991 and an overall goal is to accomplish national means and measures for control and protection of nuclear material and facilities, in order to minimise the risk of proliferation of nuclear weapons and illicit trafficking of nuclear material and equipment. The objective of the Swedish Support Programme is to help each, so called, recipient State to be able to, independently and without help from outside, take the full responsibility for operating a national non-proliferation system and thereby fulfil the requirements imposed through the international legal instruments. This would include both the development and implementation of a modern nuclear legislation system, and the establishment of the components making up a national system for combating illicit trafficking. The support and co-operation projects are organised in five Project Groups (i.e. nuclear legislation, nuclear material control, physical protection, export/import control, and combating of illicit trafficking), which together cover the entire non-proliferation area. Up till June 2000, support and co-operation projects, completed and on-going, have been carried out in ten States, namely Armenia, Azerbaijan, Belarus, Georgia, Kazakstan, Latvia, Lithuania, Moldova, Russia and Ukraine. Furthermore, programmes have been initiated during the first part of 2000 with Estonia, Uzbekistan, Kyrgyzstan and Tajikistan. In addition, assistance has been given to Poland on a specific nuclear material accountancy topic. All projects are done on request by and in co-operation with these States. The total number of projects initiated during the period 1991 to June 2000 is 109, thereof 77 have been completed and 32 are currently on-going. It is the

Self-assembled InAs quantum dots formed by molecular beam epitaxy at low temperature and postgrowth annealing

NARCIS (Netherlands)

Zhan, H.H.; Nötzel, R.; Hamhuis, G.J.; Eijkemans, T.J.; Wolter, J.H.

2003-01-01

Self-assembled InAs quantum dots are grown at low temperature (LT) by molecular beam epitaxy (MBE) on GaAs substrates. The growth is in situ monitored by reflection high-energy electron diffraction, and ex situ evaluated by atomic force microscopy for the morphological properties, and by

New process for high optical quality InAs quantum dots grown on patterned GaAs(001) substrates

NARCIS (Netherlands)

Alonso-González, Pablo; González, Luisa; González, Yolanda; Fuster, David; Fernández-Martinez, Ivan; Martin-Sánchez, Javier; Abelmann, Leon

2007-01-01

This work presents a selective ultraviolet (UV)-ozone oxidation-chemical etching process that has been used, in combination with laser interference lithography (LIL), for the preparation of GaAs patterned substrates. Further molecular beam epitaxy (MBE) growth of InAs results in ordered InAs/GaAs

American alliances and nuclear non-proliferation. The end of nuclear weapon activities of US allies

International Nuclear Information System (INIS)

Schneider, Jonas

2016-01-01

Jonas Schneider tackles a question that is of great interest both to scholars of nuclear proliferation and to practitioners of nonproliferation diplomacy: Why do some political leaders of U.S. allies agree to abandon their nation's nuclear weapons activities, while others - who are often members of the same allied government and sometimes even of the same political party - steadfastly reject such a course reversal? Our existing stock of theories does not fare well in accounting for this important variation in leaders' attitudes. To solve this puzzle, Schneider develops an innovative theory that draws on the individual status conceptions of allied political leaders. Subsequently, the author undertakes to test his theory using four thoroughly researched case studies, and he derives important lessons for international nonproliferation diplomacy toward the Middle East and Northeast Asia.

Two-color single-photon emission from InAs quantum dots: toward logic information management using quantum light.

Science.gov (United States)

Rivas, David; Muñoz-Matutano, Guillermo; Canet-Ferrer, Josep; García-Calzada, Raúl; Trevisi, Giovanna; Seravalli, Luca; Frigeri, Paola; Martínez-Pastor, Juan P

2014-02-12

In this work, we propose the use of the Hanbury-Brown and Twiss interferometric technique and a switchable two-color excitation method for evaluating the exciton and noncorrelated electron-hole dynamics associated with single photon emission from indium arsenide (InAs) self-assembled quantum dots (QDs). Using a microstate master equation model we demonstrate that our single QDs are described by nonlinear exciton dynamics. The simultaneous detection of two-color, single photon emission from InAs QDs using these nonlinear dynamics was used to design a NOT AND logic transference function. This computational functionality combines the advantages of working with light/photons as input/output device parameters (all-optical system) and that of a nanodevice (QD size of ∼ 20 nm) while also providing high optical sensitivity (ultralow optical power operational requirements). These system features represent an important and interesting step toward the development of new prototypes for the incoming quantum information technologies.

Design of a multivariable controller for a CANDU 600 MWe nuclear power plant using the INA method

International Nuclear Information System (INIS)

Roy, N.; Boisvert, J.; Mensah, S.

1984-04-01

The development of large and complex nuclear and process plants requires high-performance control systems, designed with rigorous multivariable techniques. This work is part of an analytical study demonstrating the real potential of multivariable methods. It covers every step in the design of a multi-variable controller for a Gentilly-2 type CANDU 600 MWe nuclear power plant using the Inverse Nyquist Array (INA) method. First the linear design model and its preliminary modifications are described. The design tools are reviewed and the operations required to achieve open-loop diagonal dominance are thoroughly described. Analysis of the closed-loop system is then performed and a feedback matrix is selected to meet the design specifications. The performance of the controller on the linear model is verified by simulation. Finally, the controller is implemented on the reference non-linear model to assess its overall performance. The results show that the INA method can be used successfully to design controllers for large and complex systems

Nuclear proliferation and civilian nuclear power. Report of the Nonproliferation Alternative Systems Assessment Program. Volume VII. International perspectives

Energy Technology Data Exchange (ETDEWEB)

1980-06-01

The purpose of this volume is to assess the proliferation vulnerabilities of the present deployment of civilian nuclear-power systems within the current nonproliferation regime and, in light of their prospective deployment, to consider technical and institutional measures and alternatives which may contribute to an improved regime in which nuclear power could play a significant part. An assessment of these measures must include consideration of their nonproliferation effectiveness as well as their bearing upon energy security, and their operational, economic, and political implications. The nature of these considerations can provide some measure of their likely acceptability to various nations.

Nuclear proliferation and civilian nuclear power. Report of the Nonproliferation Alternative Systems Assessment Program. Volume VII. International perspectives

International Nuclear Information System (INIS)

1980-06-01

The purpose of this volume is to assess the proliferation vulnerabilities of the present deployment of civilian nuclear-power systems within the current nonproliferation regime and, in light of their prospective deployment, to consider technical and institutional measures and alternatives which may contribute to an improved regime in which nuclear power could play a significant part. An assessment of these measures must include consideration of their nonproliferation effectiveness as well as their bearing upon energy security, and their operational, economic, and political implications. The nature of these considerations can provide some measure of their likely acceptability to various nations

BIAYA KLAIM INA CBGS DAN BIAYA RIIL PENYAKIT KATASTROPIK RAWAT INAP PESERTA JAMKESMAS DI RUMAH SAKIT STUDI DI 10 RUMAH SAKIT MILIK KEMENTERIAN KESEHATAN JANUARI–MARET 2012

Directory of Open Access Journals (Sweden)

Wasis Budiarto

2013-08-01

Full Text Available Latar belakang: Implementasi sistem INA-CBGs bagi pasien penyakit katastropik (jantung, kanker, stroke peserta Jamkesmas di rumah sakit, memberikan konsekuensi di satu pihak bahwa penyakit katastropik merupakan ancaman terhadap membengkaknya pembiayaan Jamkesmas di masa datang, sedangkan di pihak lain, rumah sakit merasakan bahwa biaya penggantian klaim INA CBGs lebih rendah dari tarif yang berlaku dirumah sakit. Tujuan: Tujuan penelitian ini untuk memperoleh gambaran biaya pengobatan penyakit katastropik dan perbandingan pembiayaan klaim berdasarkan INA-DRGs dengan biaya pengobatan riil penyakit katastropik dirumah sakit. Jenis penelitian adalah deskriptif menurut perspektif rumah sakit. Metode: Metode pengambilan data dilakukan secara retrospektif yang diambil dari penelusuran dokumen catatan medik pasien penyakit katastropik di 10 rumah sakit selama 3 bulan (Januari–Maret 2012. Analisis data dilakukan secara deskriptif. Hasil: Hasil penelitian menunjukkan bahwa pasien Jamkesmas yang dirawat dengan kasus katastropik terdiri dari penyakit jantung sebesar37,11%, penyakit kanker 23,54% dan sisanya sebesar 39,35% pasien penyakit stroke. Kesimpulan: Biaya pengobatan rawat inap berdasarkan tarif rumah sakit kelas A jauh lebih besar dibandingkan kelas B dan RS Khusus, biaya klaim berdasarkan INA-CBGs jauh lebih besar di rumah sakit kelas A dibanding kelas B dan RS Khusus. Komponen biaya yang banyak peruntukannya adalah biaya akomodasi, tindakan ruangan, pemeriksaan laboratorium, tindakan intervensi nonbedah untuk jantung, tindakan operasi untuk kanker serta biaya obat-obatan. Biaya penggantian klaim penyakit katastropik berdasarkan INA CBGs lebih besar dibandingkan dengan biaya riil berdasarkan tarif rumah sakit, sehingga untuk penyakit katastropik rumah sakit tidak merugi. Untuk itu pelaksanaan kebijakan rujukan berjenjang bagi peserta Jamkesmas harus diawasi secara ketat sehingga pelayanan kesehatan bagi penduduk miskin menjadi lebih terjamin

Effects of InAlAs strain reducing layer on the photoluminescence properties of InAs quantum dots embedded in InGaAs/GaAs quantum wells

Energy Technology Data Exchange (ETDEWEB)

Kong, Lingmin, E-mail: konglm@qq.com [School of Marine Science and Technology, Zhejiang Ocean University, Zhoushan 316000 (China); Sun, Wei [SEM School of Electromechanical Engineering, Weifang Engineering Vocational College, Qingzhou 262500 (China); Feng, Zhe Chuan, E-mail: zcfeng@nut.edu.tw [Institute of Photonics and Optoelectronics, Department of Electrical Engineering, and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei 106-17, Taiwan (China); Xie, Sheng [School of Electronic and Information Engineering, Tianjin University, Tianjin 300072 (China); Zhou, Yunqing; Wang, Rui; Zhang, Cunxi; Zong, Zhaocun; Wang, Hongxia; Qiao, Qian [Department of Physics, Zhejiang Ocean University, Zhoushan 316000 (China); Wu, Zhengyun [Department of Physics, Xiamen University, Xiamen 361005 China (China)

2014-07-01

Two kinds of self-assembled quantum dots (QDs) embedded within InGaAs/GaAs quantum wells were grown by molecular beam epitaxy: one was capped with an InAlAs strain reducing (SR) layer, while the other was not. Their emission dynamics was investigated by time-resolved and temperature dependent (TD) photoluminescence (PL) measurements. A significant redshift can be observed in the emission peak position of InAs QDs with thin InAlAs SR cap layer, which results from SR effects. Different behaviors of the integrated PL intensity for the samples with or without InAlAs layer may be ascribed to the reduced carrier transition at higher temperature for the higher energy barrier of the InAlAs layer, and the TD mode of carrier migration. The PL decay time of quantum dots grown with InAlAs layer was much longer than that without the layer, which implies that the InAlAs layer with higher energy barrier may enhance the quantum restriction of carriers in InAs QDs. These observations are discussed from the viewpoint of strain compensation and potential barrier variation with SR layers. Our experiments also demonstrate that the main mode of carrier migration is quantum tunneling effect at lower temperature, while it is quantum transition at higher temperature. The results demonstrate the importance of InAlAs SR layer for the optical quality of InAs QDs. - Highlights: • InAs quantum dots (QDs) were grown on GaAs. • A thin InAlAs layer was grown on InAs QDs. • Temperature dependent photoluminescence (PL) and time-resolved PL were carried out. • Both a redshift and a double exponential decay of PL emission were generated by the InAlAs layer.

Making Mn substitutional impurities in InAs using a scanning tunneling microscope.

Science.gov (United States)

Song, Young Jae; Erwin, Steven C; Rutter, Gregory M; First, Phillip N; Zhitenev, Nikolai B; Stroscio, Joseph A

2009-12-01

We describe in detail an atom-by-atom exchange manipulation technique using a scanning tunneling microscope probe. As-deposited Mn adatoms (Mn(ad)) are exchanged one-by-one with surface In atoms (In(su)) to create a Mn surface-substitutional (Mn(In)) and an exchanged In adatom (In(ad)) by an electron tunneling induced reaction Mn(ad) + In(su) --> Mn(In) + In(ad) on the InAs(110) surface. In combination with density-functional theory and high resolution scanning tunneling microscopy imaging, we have identified the reaction pathway for the Mn and In atom exchange.

Improving Capture-gamma Libraries for Nonproliferation Applications

Energy Technology Data Exchange (ETDEWEB)

Sleaford, Brad W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hurst, Aaron M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)

2016-11-01

This report describes the measurement, evaluation and incorporation of new -ray spectroscopic data into the Evaluated Nuclear Data File (ENDF) for nonproliferation applications. Analysis and processing techniques are described along with key deliverables that have been met over the course of this project. A total of nine new ENDF libraries have been submitted to the National Nuclear Data Center at the Brookhaven National Laboratory and are now available in the ENDF/B-VIII.beta2 release. Furthermore, this project has led to more than ten peer-reviewed publications and provided theses for ve graduate students. This project is a component of the NA-22 venture collaboration on \\Correlated Nuclear Data in Fission Events" (LA14-V-CorrData-PD2Jb).

Naval nuclear propulsion and the international nonproliferation regime

International Nuclear Information System (INIS)

Guimaraes, Leonam dos Santos

2005-01-01

Nuclear powered attack submarine (SSN) acquisition by Non-Proliferation Treaty No- Nuclear Weapon State (NPT-NNWS) Navies does not imply nuclear weapon proliferation risks higher than those related to stationary research and power reactors. It must then be recognized that stringent restraints on supplies and political pressures on governments, both exercised very effectively by No-Proliferation Treaty - Nuclear Weapon State (NPT-NWS) against NPT-NNWS indigenous development of SSN and associated fuel cycle facilities, are fundamentally based on geopolitical and military strategic objectives. This practice is far from being related exclusively to the NPT spirit: in fact, it is a matter of freedom at seas and not of nuclear proliferation. (author)

A modified gradient approach for the growth of low-density InAs quantum dot molecules by molecular beam epitaxy

Science.gov (United States)

Sharma, Nandlal; Reuter, Dirk

2017-11-01

Two vertically stacked quantum dots that are electronically coupled, so called quantum dot molecules, are of great interest for the realization of solid state building blocks for quantum communication networks. We present a modified gradient approach to realize InAs quantum dot molecules with a low areal density so that single quantum dot molecules can be optically addressed. The individual quantum dot layers were prepared by solid source molecular beam epitaxy depositing InAs on GaAs(100). The bottom quantum dot layer has been grown without substrate rotation resulting in an In-gradient across the surface, which translated into a density gradient with low quantum dot density in a certain region of the wafer. For the top quantum dot layer, separated from the bottom quantum dot layer by a 6 nm thick GaAs barrier, various InAs amounts were deposited without an In-gradient. In spite of the absence of an In-gradient, a pronounced density gradient is observed for the top quantum dots. Even for an In-amount slightly below the critical thickness for a single dot layer, a density gradient in the top quantum dot layer, which seems to reproduce the density gradient in the bottom layer, is observed. For more or less In, respectively, deviations from this behavior occur. We suggest that the obvious influence of the bottom quantum dot layer on the growth of the top quantum dots is due to the strain field induced by the buried dots.

Nonlinear absorption and receptivity of the third order in InAs infrared region

International Nuclear Information System (INIS)

Musayev, M.A.

2005-01-01

Nonlinear absorption and receptivity of the third order and coefficient nonlinear absorption in InAs n-type with different degree of alloying was measured. Obtained score considerably exceed sense, calculated on the basis of the models describing nonlinear receptivity of electrons, situated in the nonparabolic area of conductivity. It was shown that, observable deviations withdraw; if in the calculation apply energy dissipation of electrons. Growth of the efficiency under four-wave interaction in low-energy-gap semiconductors confines nonlinear absorption of interacting waves

AN ANALYTICAL FRAMEWORK FOR ASSESSING RELIABLE NUCLEAR FUEL SERVICE APPROACHES: ECONOMIC AND NON-PROLIFERATION MERITS OF NUCLEAR FUEL LEASING

International Nuclear Information System (INIS)

Kreyling, Sean J.; Brothers, Alan J.; Short, Steven M.; Phillips, Jon R.; Weimar, Mark R.

2010-01-01

The goal of international nuclear policy since the dawn of nuclear power has been the peaceful expansion of nuclear energy while controlling the spread of enrichment and reprocessing technology. Numerous initiatives undertaken in the intervening decades to develop international agreements on providing nuclear fuel supply assurances, or reliable nuclear fuel services (RNFS) attempted to control the spread of sensitive nuclear materials and technology. In order to inform the international debate and the development of government policy, PNNL has been developing an analytical framework to holistically evaluate the economics and non-proliferation merits of alternative approaches to managing the nuclear fuel cycle (i.e., cradle-to-grave). This paper provides an overview of the analytical framework and discusses preliminary results of an economic assessment of one RNFS approach: full-service nuclear fuel leasing. The specific focus of this paper is the metrics under development to systematically evaluate the non-proliferation merits of fuel-cycle management alternatives. Also discussed is the utility of an integrated assessment of the economics and non-proliferation merits of nuclear fuel leasing.

Accountability and non-proliferation nuclear regime: a review of the mutual surveillance Brazilian-Argentine model for nuclear safeguards

International Nuclear Information System (INIS)

Xavier, Roberto Salles

2014-01-01

The regimes of accountability, the organizations of global governance and institutional arrangements of global governance of nuclear non-proliferation and of Mutual Vigilance Brazilian-Argentine of Nuclear Safeguards are the subject of research. The starting point is the importance of the institutional model of global governance for the effective control of non-proliferation of nuclear weapons. In this context, the research investigates how to structure the current arrangements of the international nuclear non-proliferation and what is the performance of model Mutual Vigilance Brazilian-Argentine of Nuclear Safeguards in relation to accountability regimes of global governance. For that, was searched the current literature of three theoretical dimensions: accountability, global governance and global governance organizations. In relation to the research method was used the case study and the treatment technique of data the analysis of content. The results allowed: to establish an evaluation model based on accountability mechanisms; to assess how behaves the model Mutual Vigilance Brazilian-Argentine Nuclear Safeguards front of the proposed accountability regime; and to measure the degree to which regional arrangements that work with systems of global governance can strengthen these international systems. (author)

Theoretical interpretation of the electron mobility behavior in InAs nanowires

International Nuclear Information System (INIS)

Marin, E. G.; Ruiz, F. G.; Godoy, A.; Tienda-Luna, I. M.; Martínez-Blanque, C.; Gámiz, F.

2014-01-01

This work studies the electron mobility in InAs nanowires (NWs), by solving the Boltzmann Transport Equation under the Momentum Relaxation Time approximation. The numerical solver takes into account the contribution of the main scattering mechanisms present in III-V compound semiconductors. It is validated against experimental field effect-mobility results, showing a very good agreement. The mobility dependence on the nanowire diameter and carrier density is analyzed. It is found that surface roughness and polar optical phonons are the scattering mechanisms that mainly limit the mobility behavior. Finally, we explain the origin of the oscillations observed in the mobility of small NWs at high electric fields.

Theoretical interpretation of the electron mobility behavior in InAs nanowires

Energy Technology Data Exchange (ETDEWEB)

Marin, E. G., E-mail: egmarin@ugr.es; Ruiz, F. G., E-mail: franruiz@ugr.es; Godoy, A.; Tienda-Luna, I. M.; Martínez-Blanque, C.; Gámiz, F. [Departamento de Electrónica y Tecnología de los Computadores, Facultad de Ciencias, Universidad de Granada, Av. Fuentenueva S/N, 18071 Granada (Spain)

2014-11-07

This work studies the electron mobility in InAs nanowires (NWs), by solving the Boltzmann Transport Equation under the Momentum Relaxation Time approximation. The numerical solver takes into account the contribution of the main scattering mechanisms present in III-V compound semiconductors. It is validated against experimental field effect-mobility results, showing a very good agreement. The mobility dependence on the nanowire diameter and carrier density is analyzed. It is found that surface roughness and polar optical phonons are the scattering mechanisms that mainly limit the mobility behavior. Finally, we explain the origin of the oscillations observed in the mobility of small NWs at high electric fields.

Improvement of the optical quality of site-controlled InAs quantum dots by a double stack growth technique in wet-chemically etched holes

Energy Technology Data Exchange (ETDEWEB)

Pfau, Tino Johannes; Gushterov, Aleksander; Reithmaier, Johann-Peter [Technische Physik, INA, Universitaet Kassel (Germany); Cestier, Isabelle; Eisenstein, Gadi [Electrical Engineering Dept., Technion, Haifa (Israel); Linder, Evgany; Gershoni, David [Solid State Institute and Physics Dept., Technion, Haifa (Israel)

2010-07-01

The optimization of the wet-chemically etching of holes and a special MBE growth stack technique allows enlarging the site-control of low density InAs QDs on GaAs substrates up to a buffer layer thickness of 55 nm. The strain of InAs QDs, grown in the etched holes, reduces the hole closing, so that a pre-patterned surface is conserved for the second QD layer. The distance of 50 nm GaAs between the two QD layers exceeds drastically the maximum vertical alignment based on pure strain coupling (20 nm). Compared to stacks with several QD layers, this method avoids electronic coupling between the different QD layers and reduces the problems to distinguish the dots of different layers optically. Confocal microphotoluminescence reveals a significant diminution of the low temperature photoluminescence linewidth of the second InAs QD layer to an average value of 505{+-}53 {mu}eV and a minimum width of 460 {mu}eV compared to 2 to 4 meV for QDs grown on thin buffer layers. The increase of the buffer layer thickness decreases the influence of the surface defects caused by prepatterning.

The Future of Nonproliferation in a Changed and Changing Environment: A Workshop Summary

International Nuclear Information System (INIS)

Dreicer, M.

2016-01-01

The Center for Global Security Research and Global Security Principal Directorate at Lawrence Livermore National Laboratory convened a workshop in July 2016 to consider ''The Future of Nonproliferation in a Changed and Changing Security Environment.'' We took a broad view of nonproliferation, encompassing not just the treaty regime but also arms control, threat reduction, counter-roliferation, and countering nuclear terrorism. We gathered a group of approximately 60 experts from the technical, academic, political, defense and think tank communities and asked them what and how much can reasonably be accomplished in each of these areas in the 5 to 10 years ahead. Discussion was on a not-for-attribution basis. This document provides a summary of key insights and lessons learned, and is provided to help stimulate broader public discussion of these issues. It is a collection of ideas as informally discussed and debated among a group of experts. The ideas reported here are the personal views of individual experts and should not be attributed to Lawrence Livermore National Laboratory.

The Future of Nonproliferation in a Changed and Changing Environment: A Workshop Summary

Energy Technology Data Exchange (ETDEWEB)

Dreicer, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2016-08-30

The Center for Global Security Research and Global Security Principal Directorate at Lawrence Livermore National Laboratory convened a workshop in July 2016 to consider “The Future of Nonproliferation in a Changed and Changing Security Environment.” We took a broad view of nonproliferation, encompassing not just the treaty regime but also arms control, threat reduction, counter-­proliferation, and countering nuclear terrorism. We gathered a group of approximately 60 experts from the technical, academic, political, defense and think tank communities and asked them what—and how much—can reasonably be accomplished in each of these areas in the 5 to 10 years ahead. Discussion was on a not-­for-­attribution basis. This document provides a summary of key insights and lessons learned, and is provided to help stimulate broader public discussion of these issues. It is a collection of ideas as informally discussed and debated among a group of experts. The ideas reported here are the personal views of individual experts and should not be attributed to Lawrence Livermore National Laboratory.

Post-Cold War Effects on the Non-proliferation Regime

Energy Technology Data Exchange (ETDEWEB)

Kessler, Carol E.

2006-03-31

This journal article analyzes nuclear and security related events of the past 15 years to illustrate the changes in geopolitics and the shifting balance of power following the collapse of the Soviet Union. Reflection upon these events establishes the context for strengthening the nonproliferation regime. The author concludes that post Soviet communism hastened the movement towards a unipolar system with hegemonic power vested in the United States, and this geopolitical imbalance fostered insecurities and greater threats. Multilateral cooperation and commitment from the US would help this leader achieve its goal of security through increased global confidence in the international system.

Saving the NPT: past and future non-proliferation bargains

Energy Technology Data Exchange (ETDEWEB)

Tertrais, B

2005-07-01

In this thorough study of the Nuclear Nonproliferation Treaty (NPT), the author looks at the origins of the NPT, its original bargains, and the current 'global crisis of compliance'. Then he looks to the 2005 NPT Review Conference for approaches 'to preserve the integrity and the credibility of the Treaty'. He suggests a new set of bargains centered around two issues: increase rewards for members in good standing of their obligations, but promote sanctions for those cheating; and recognize that nuclear disarmament is a distant goal, but satisfy the legitimate worries of NNWS (Non-Nuclear Weapon States)

Saving the NPT: past and future non-proliferation bargains

International Nuclear Information System (INIS)

Tertrais, B.

2005-01-01

In this thorough study of the Nuclear Nonproliferation Treaty (NPT), the author looks at the origins of the NPT, its original bargains, and the current 'global crisis of compliance'. Then he looks to the 2005 NPT Review Conference for approaches 'to preserve the integrity and the credibility of the Treaty'. He suggests a new set of bargains centered around two issues: increase rewards for members in good standing of their obligations, but promote sanctions for those cheating; and recognize that nuclear disarmament is a distant goal, but satisfy the legitimate worries of NNWS (Non-Nuclear Weapon States)

The European Safeguards Research and Development Association Addresses Safeguards and Nonproliferation

International Nuclear Information System (INIS)

Janssens-Maenhout, Greet; Kusumi, R.; Daures, Pascal A.; Janssens, Willem; Dickman, Deborah A.

2010-01-01

The renaissance of efforts to expand the use of nuclear energy requires the parallel development of a renewed and more sophisticated work force. Growth in the nuclear sector with high standard of safety, safeguards and security requires skilled staff for design, operations, inspections etc. High-quality nuclear technology educational programs are diminished from past years, and the ability of universities to attract students and to meet future staffing requirements of the nuclear industry is becoming seriously compromised. Thus, education and training in nuclear engineering and sciences is one of the cornerstones for the nuclear sector. Teaching in the nuclear field still seems strongly influenced by national history but it is time to strengthen resources and collaborate. Moreover with the current nuclear security threats it becomes critical that nuclear technology experts master the basic principles not only of safety, but also of nuclear safeguards, nonproliferation and nuclear security. In Europe the European Nuclear Education Network (ENEN) Association has established the certificate 'European Master of Science in Nuclear Engineering (EMSNE)' as the classic nuclear engineering program covering reactor operation and nuclear safety. However, it does not include courses on nonproliferation, safeguards, or dual-use technologies. The lack of education in nuclear safeguards was tackled by the European Safeguards Research and Development Association (ESARDA), through development and implementation of safeguards course modules. Since 2005 the ESARDA Working Group, called the Training and Knowledge Management Working Group, (TKMWG) has worked with the Joint Research Centre (JRC) in Ispra, Italy to organize a Nuclear Safeguards and Nonproliferation course. This five-day course is held each spring at the JRC, and continues to show increasing interest as evidenced by the positive responses of international lecturers and students. The standard set of lectures covers a broad

Explosive performance on the non-proliferation experiment

Energy Technology Data Exchange (ETDEWEB)

McKown, T.O.

1994-03-01

The non-proliferation experiment, originally called the chemical kiloton experiment, was planned and executed by Lawrence Livermore National Laboratory to investigate the seismic yield relationship and distinguishing seismic signals between a nuclear event and a large mass conventional explosion. The Los Alamos National Laboratory planned and conducted experiments to further their studies of the source function for signals observed seismically. Since all investigations were contingent on the performance of the emplaced chemical explosive, an array of diagnostic measurements was fielded in the emplaced explosive. The CORRTEX system was used to investigate the explosive initiation and to determine the detonation velocities in multiple levels and in numerous directions. A description of the CORRTEX experiments fielded, a review of the data obtained and some interpretations of the data are reported.

Non-proliferation and advances in nuclear science

International Nuclear Information System (INIS)

Iyengar, P.K.

1995-01-01

So far, the non-proliferation treaty (NPT) has concentrated on safeguard regimes based on technologies relating to the production of uranium and plutonium in nuclear reactors, and on their potential diversion for use in nuclear weapons. As nuclear science advances, however, nuclear technology both peaceful and for weapons will change, and for the NPT to remain relevant, it must reflect these changes. At this juncture, when the NPT is coming up for review in a year's time, it is important for physicists to take a fresh look at recent advances in nuclear science, and inform the policy-makers and the public at large about their potential for impacting nuclear technology in the future. In this article a few such advances are highlighted and their implications for the NPT are considered. (author). 4 refs

Arms control and nonproliferation technologies. First quarter 1995

Energy Technology Data Exchange (ETDEWEB)

Staehle, G; Alonzo, G M; Sanford, N M [eds.

1995-01-01

This first quarter issue for 1995 highlights the Small Business Innovation Research (SBIR) program. The SBIR program is managed by the DOE`s Basic Energy Sciences program within the Office of Energy Research. Each year, the SBIR program solicits research ideas of interest to the DOE. Articles contained in this issue include: The Small Business Innovation Research Program supported by the Office of Nonproliferation and National Security; Automated cueing to man-made objects via multispectral image; Security systems get smart with advanced processing and thermal imaging; A breakthrough in cooling system technology; The APSTNG neutron probe; Lithium-doped fullerene neutron detector; Miniature GC-MS for on-site chemical analysis; and Winner of Sandia President`s Quality Award.

Future of US utilities under non-proliferation policy

International Nuclear Information System (INIS)

Ladesich, J.N.

1978-01-01

The non-proliferation policy, a negative policy that closes the back end of the nuclear fuel cycle, is only a small part of a chaotic energy environment characterized by inaction. The impact of this environment on California utilities has resulted in a virtual moratorium on new facilities at a time when the nuclear option can be shown to be vital. Utilities are experiencing uncertainties in future power generation because alternatives to nuclear energy may not be the best choices. Utilities feel frustrated by the inaction; not by the objectives of the accountability and security proposals. The utilities will continue to support nuclear power and the completion of the fuel cycle in spite of these uncertainties

The Effect of INA [(R)-1-O-(1-Pyrenylmethyl)Glycerol] Insertions on the Structure and Biological Activity of a G-Quadruplex from a Critical Kras G-Rich Sequence

DEFF Research Database (Denmark)

Cogoi, Susanna; Paramasivan, Manikandan; Xodo, Luigi E.

2007-01-01

Quadruplex-forming oligonucleotides containing INA [(R)-1-O-(1-pyrenylmethyl)glycerol] insertions have been designed and studied for their capacity to inhibit the expression of the KRAS oncogene in pancreatic adenocarcinoma cells. It is found that INA can influence the folding topology of the G-q...

Auger recombination in p-type InAs and in Gasub(x)Insub(1-x)As solid solutions

International Nuclear Information System (INIS)

Zotova, N.V.; Yassievich, I.N.

1977-01-01

The probability of the Auger recombination in p-type semiconductors, which is accompanied by transition of the second hole into the zone, splitted by spin-orbital interaction, was calculated. The above process is effective when the energy of spin-orbital splitting off Δ is close to the forbidden zone energy Esub(g), which takes place in the case of InAs, GaSb and solid solutions based on these compounds. The calculation is performed for the non-degenerate hole gas at a finite difference of Esub(g) - Δ. By means of the study of radiative recombination in InAs and Gasub(x)Insub(1-x)As solid solutions with small contents of GaAs (0 17 cm -3 . It is found that the quantum yield of radiative recombination increases sharply in Gasub(x)Insub(1-x)As solid solutions with the increase of x, which is associated with the increase of the difference of Esub(g) - Δ; the radiative recombination intensity increases in correspondence with the theoretical calculation made

Nonproliferation, disarmament and the security link

International Nuclear Information System (INIS)

Raja Mohan, C.

1997-01-01

It is obvious that nuclear weapons are here to stay for a long time to come. Many nation states are likely to operate on the premise that the combination of nuclear weapons and long range missile provides an unrivalled source of power. The United States and India cannot hope to structure cooperation on the hope that nuclear weapons can be marginalised and eventually eliminated from the international calculus of power. Nor can they go by the premise that the existing structure of international power can be frozen through the strengthening of the current nonproliferation regime. Continued diffusion of power and the spread of technology as well as the political dynamics could break the current order. This bleak assessment does not however imply that there are no prospects for cooperation between India and the United States. If both the nations move towards a more realistic policy positions and locate their nuclear dialogue in a broader strategic context, it should not be impossible to develop areas of cooperation

Missile non-proliferation: an alternative approach

International Nuclear Information System (INIS)

Delory, Stephane

2011-01-01

In this report, the author first proposes an overview of the notion of missile prohibition. He notices that the association between weapons of mass destruction and missiles is a prelude to the legitimacy of missile control, notably within the framework of the Missile Technology Control Regime or MTCR. He also comments the notion of total ban. In a second part, the author analyses and discusses the limitations of the control of technology diffusion. He discusses the role of the MTCR, comments the evolution of this regime with the taking of China and Russia into consideration, the impacts of national implementations of export regimes on the MTCR, and economic aspects of control implementation. In the next part, the author addresses other kinds of limitations, i.e. those related with capacity evolutions of proliferating States. The last part addresses the evolution towards a new definition of approach to missile non-proliferation, notably in terms of perception of missile roles and of technology transfer controls

INFCE and US non-proliferation policy

Energy Technology Data Exchange (ETDEWEB)

Donnelly, W H

1980-12-01

The International Fuel Cycle Evaluation (INFCE), which published its final reports in February 1980 produced a massive international effort of a kind never before seen. Over a period of two years its eight working groups held 61 meetings involving 519 experts from 46 countries and five international organizations. Here the author outlines the background and structure of INFCE and discusses how its recommendations diverge from US nonproliferation policy. If the future of nuclear power is to include more sensitive facilities in which plutonium and highly enriched uranium are present, it must be determined whether the risks seen in proliferation are great enough to cause the USA and other governments to place such facilities under some form of international ownership or control in addition to international safeguards. A final crucial problem is deciding what can and should be done to dissuade non-nuclear-weapons states from the direct manufacture of nuclear weapons. 6 references.

Direct radiocarbon dates for Vindija G1 and Velika Pećina Late Pleistocene hominid remains

Science.gov (United States)

Smith, Fred H.; Trinkaus, Erik; Pettitt, Paul B.; Karavanić, Ivor; Paunović, Maja

1999-01-01

New accelerator mass spectrometry radiocarbon dates taken directly on human remains from the Late Pleistocene sites of Vindija and Velika Pećina in the Hrvatsko Zagorje of Croatia are presented. Hominid specimens from both sites have played critical roles in the development of current perspectives on modern human evolutionary emergence in Europe. Dates of ≈28 thousand years (ka) before the present (B.P.) and ≈29 ka B.P. for two specimens from Vindija G1 establish them as the most recent dated Neandertals in the Eurasian range of these archaic humans. The human frontal bone from Velika Pećina, generally considered one of the earliest representatives of modern humans in Europe, dated to ≈5 ka B.P., rendering it no longer pertinent to discussions of modern human origins. Apart from invalidating the only radiometrically based example of temporal overlap between late Neandertal and early modern human fossil remains from within any region of Europe, these dates raise the question of when early modern humans first dispersed into Europe and have implications for the nature and geographic patterning of biological and cultural interactions between these populations and the Neandertals. PMID:10535913

Spin-lattice relaxation times and knight shift in InSb and InAs

International Nuclear Information System (INIS)

Braun, P.; Grande, S.

1976-01-01

For a dominant contact interaction between nuclei and conduction electrons the relaxation rate is deduced. The extreme cases of degenerate and non-degenerate semiconductors are separately discussed. At strong degeneracy the product of the Knight shift and relaxation time gives the Korringa relation for metals. Measurements of the NMR spin-lattice relaxation times of 115 InSb and 115 InAs were made between 4.2 and 300 K for strongly degenerated samples. The different relaxation mechanisms are discussed and the experimental and theoretical results are compared. (author)

Unit Cell Structure of Crystal Polytypes in InAs and InSb Nanowires

DEFF Research Database (Denmark)

Kriegner, Dominik; Panse, Christian; Mandl, Bernhard

2011-01-01

The atomic distances in hexagonal polytypes of III−V compound semiconductors differ from the values expected from simply a change of the stacking sequence of (111) lattice planes. While these changes were difficult to quantify so far, we accurately determine the lattice parameters of zinc blende......, wurtzite, and 4H polytypes for InAs and InSb nanowires, using X-ray diffraction and transmission electron microscopy. The results are compared to density functional theory calculations. Experiment and theory show that the occurrence of hexagonal bilayers tends to stretch the distances of atomic layers...

Direct-Bandgap InAs Quantum-Dots Have Long-Range Electron--Hole Exchange Whereas Indirect Gap Si Dots Have Short-Range Exchange

International Nuclear Information System (INIS)

Juo, J.W.; Franceschetti, A.; Zunger, A.

2009-01-01

Excitons in quantum dots manifest a lower-energy spin-forbidden 'dark' state below a spin-allowed 'bright' state; this splitting originates from electron-hole (e-h) exchange interactions, which are strongly enhanced by quantum confinement. The e-h exchange interaction may have both a short-range and a long-range component. Calculating numerically the e-h exchange energies from atomistic pseudopotential wave functions, we show here that in direct-gap quantum dots (such as InAs) the e-h exchange interaction is dominated by the long-range component, whereas in indirect-gap quantum dots (such as Si) only the short-range component survives. As a result, the exciton dark/bright splitting scales as 1/R 2 in InAs dots and 1/R 3 in Si dots, where R is the quantum-dot radius.

Crisis as opportunity. Implications of the nuclear conflict with Iran for the nuclear non-proliferation regime

International Nuclear Information System (INIS)

Meier, Oliver

2014-01-01

The conflict over the Iranian nuclear programme represents the greatest challenge for international efforts to prevent nuclear proliferation. For decades Iran has been violating obligations contained in its safeguards agreement with the International Atomic Energy Agency (IAEA) in order to become nuclear weapons capable. But what impact does the conflict over Tehran's nuclear programme have on the nuclear non-proliferation regime? In three areas there is significant overlap between efforts to find a solution with Iran and broader discussions about strengthening non-proliferation norms, rules and procedures: verification of civilian nuclear programmes, limiting the ability to produce weapons-grade fissile materials, and nuclear fuel supply guarantees. The nuclear dispute with Tehran is likely to have specific effects in each of these fields on the non-proliferation regime's norms, rules and procedures. The ninth NPT review conference, which will take place from 27 April to 22 May 2015, offers an opportunity to draw lessons from the nuclear conflict and discuss ideas for further strengthening the regime. Germany is the only non-nuclear-weapon state within the E3+3 group and the strongest proponent of nuclear disarmament. As a supporter of effective multilateralism, Berlin also bears a special responsibility for ensuring that steps to strengthen nuclear verification and control efforts in the talks with Iran also reflect the non-nuclear-weapon states' interest in disarmament and transparency on the part of the nuclear-weapons states.

Crisis as opportunity. Implications of the nuclear conflict with Iran for the nuclear non-proliferation regime

Energy Technology Data Exchange (ETDEWEB)

Meier, Oliver

2014-11-15

The conflict over the Iranian nuclear programme represents the greatest challenge for international efforts to prevent nuclear proliferation. For decades Iran has been violating obligations contained in its safeguards agreement with the International Atomic Energy Agency (IAEA) in order to become nuclear weapons capable. But what impact does the conflict over Tehran's nuclear programme have on the nuclear non-proliferation regime? In three areas there is significant overlap between efforts to find a solution with Iran and broader discussions about strengthening non-proliferation norms, rules and procedures: verification of civilian nuclear programmes, limiting the ability to produce weapons-grade fissile materials, and nuclear fuel supply guarantees. The nuclear dispute with Tehran is likely to have specific effects in each of these fields on the non-proliferation regime's norms, rules and procedures. The ninth NPT review conference, which will take place from 27 April to 22 May 2015, offers an opportunity to draw lessons from the nuclear conflict and discuss ideas for further strengthening the regime. Germany is the only non-nuclear-weapon state within the E3+3 group and the strongest proponent of nuclear disarmament. As a supporter of effective multilateralism, Berlin also bears a special responsibility for ensuring that steps to strengthen nuclear verification and control efforts in the talks with Iran also reflect the non-nuclear-weapon states' interest in disarmament and transparency on the part of the nuclear-weapons states.

The Non-Proliferation Treaty on the threshold to the 21st century

International Nuclear Information System (INIS)

Fischer, W.

1991-06-01

The basic outlines of non-proliferation policy, its instruments, the position of the protagonists' interests and the fundamental fields of conflict are to the fore. The history and structure of international non-poliferation policy and, in particular, of the NPT, are described, the instruments for verifying the purely peaceful use of nuclear power (safeguards) are analysed, and important future technological and political challenges of the Treaty are listed. (orig./HP) [de

Four decades of living with the genie: United States nuclear export policy

International Nuclear Information System (INIS)

Kramish, A.

1983-01-01

The subject is discussed as follows: general introduction (examples of complex nature of nuclear trade); non-proliferation policy - the beginnings (early US action to control dealings with other countries); the Nuclear Non-Proliferation Act of 1978 (formulation of US policy on nuclear trade; INFCE (International Nuclear Fuel Cycle Evaluation)); the Symington and Glenn Amendments (US legislation to control trade with other countries); the Export-Import Bank Act (US legislation for the same purpose as above); the Non-Proliferation Treaty; the Reagan Policy (US present policy to support IAEA safeguards and Non-Proliferation Treaty); future prospects. (U.K.)

Nonlinear absorption and transmission properties of Ge, Te and InAs using tuneable IR FEL

Energy Technology Data Exchange (ETDEWEB)

Amirmadhi, F.; Becker, K.; Brau, C.A. [Vanderbilt Univ., Nashville, TN (United States)

1995-12-31

Nonlinear absorption properties of Ge, Te and InAs are being investigated using the transmission of FEL optical pulses through these semiconductors (z-scan method). Wavelength, intensity and macropulse dependence are used to differentiate between two-photon and free-carrier absorption properties of these materials. Macropulse dependence is resolved by using a Pockles Cell to chop the 4-{mu}s macropulse down to 100 ns. Results of these experiments will be presented and discussed.

Iran's Relations to the East: Nonproliferation and Regional Security in a Changing Southwest Asia

Energy Technology Data Exchange (ETDEWEB)

Tehsin, Muhammad [Quaid-I-Azam Univ., Islamabad (Pakistan)

2014-11-01

This study attempts to answer the following questions: would a successful JPOA result in nuclear nonproliferation and regional security in Southwest Asia; and could the Middle East and South Asia work together to contain the threat of Salafi jihadism?

Nuclear Deterrence in the Age of Nonproliferation

Energy Technology Data Exchange (ETDEWEB)

Richardson, J

2009-01-21

The fallacy of zero nuclear weapons, even as a virtual goal, is discussed. Because the complete abolition of nuclear weapons is not verifiable, nuclear weapons will always play a role in the calculus of assure, dissuade, deter and defeat (ADDD). However, the relative contribution of nuclear weapons to international security has diminished. To reconstitute the Cold War nuclear capability, with respect to both the nuclear weapons capability and their associated delivery systems, is fiscally daunting and not warranted due to competing budgetary pressures and their relative contribution to international security and nonproliferation. A proposed pathway to a sustainable nuclear weapons capability end-state is suggested which provides enough ADDD; a Dyad composed of fewer delivery and weapon systems, with trickle production at the National Laboratories and private sector to maintain capability and guard against technological surprise.

20 CFR 668.700 - What process must an INA grantee use to plan its employment and training services?

Science.gov (United States)

2010-04-01

... it uses to plan other activities and services. (b) However, in the process of preparing its Two Year... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false What process must an INA grantee use to plan its employment and training services? 668.700 Section 668.700 Employees' Benefits EMPLOYMENT AND...

Passive measurements of mixed-oxide fuel for nuclear nonproliferation

International Nuclear Information System (INIS)

Dolan, Jennifer L.; Flaska, Marek; Pozzi, Sara A.; Chichester, David L.

2013-01-01

We present new results on passive measurements and simulations of mixed-oxide fuel-pin assemblies. Potential tools for mixed-oxide fuel pin characterization are discussed for future nuclear-nonproliferation applications. Four EJ-309 liquid scintillation detectors coupled with an accurate pulse timing and digital, offline and optimized pulse-shape discrimination method were used. Measurement analysis included pulse-height distributions to distinguish between purely fission neutron sources and alpha-n plus fission neutrons sources. Time-dependent cross-correlation functions were analyzed to measure the fission neutron contribution to the measured sample's neutron source. The use of Monte Carlo particle transport code MCNPX-PoliMi is discussed in conjunction with the measurements

The non-proliferation policies of non-nuclear-weapon states

International Nuclear Information System (INIS)

Marwah, Onkar

1987-01-01

Eight countries are considered to be capable of producing nuclear weapons and highly suspect in their intentions to actually produce them. These are Argentina, Brazil, India, Pakistan, Israel, South Africa, the Republic of Korea and Taiwan. The policies of these suspect Non-nuclear-weapon States (NNWS) are considered in this paper. The first part assesses the non-proliferation (or proliferation) policies of the eight suspect NNWS, the second part evaluates their differences in approach from the policies urged upon them by the nuclear-weapon states (NWS) and the third and final part attempts to understand the future evolution of NNWS policies in the nuclear military field. (U.K.)

Scientists for non-proliferation of nuclear weapons. Transactions of international seminar

International Nuclear Information System (INIS)

1994-01-01

This publication presents the results of the Second International Seminar 'Scientists for Non-Proliferation of Nuclear Weapons'. The Seminar took place from 11 to 14 October 1994 in Nakhabino Country Club near Moscow. More than 60 specialists from Russia, USA, France, Belgium as well as IAEA and CEU took part in the seminar. Problems of cooperation in the field of nuclear materials accounting, control and safeguards, physical protection of nuclear materials, nuclear export regulations and disarmament control are discussed at the seminar

Mieloencefalite protozoária eqüina (Relato de caso.

Directory of Open Access Journals (Sweden)

R. C. Gonçalves

2005-03-01

Full Text Available RESUMO :O objetivo deste trabalho foi relatar um caso de mieloencefalite protozoária eqüina no Estado de São Paulo, Brasil. O diagnóstico se baseou nos sinais clínicos, no resultado positivo para anticorpos contra Sarcocystis neurona no soro e no líquor pela técnica de Western blot. Palavras chave: Mieloencefalite, Sarcocystis neurona, eqüinos. SUMMARY: The purpose of this work was to present a case of equine protozoal myeloencephalitis (EPM in the State of São Paulo, Brazil. The diagnosis was based on the clinical sings, the positive results of the serum and cerebrospinal fluid analysis (Western blot for antibodies against Sarcocystis neurona. Keywords: Myeloencephalitis, Sarcocystis neurona,

Act of 9 Februray 1981 on the conditions for the export of nuclear material and equipment and of nuclear technological data

International Nuclear Information System (INIS)

1981-01-01

The purpose of this Act is to implement international agreements on the non-proliferation of nuclear weapons and in particular, to prevent the transfer of materials, equipment and technological data likely to be used for non-peaceful purposes. Therefore each transfer of this type is subject to prior authorisation by the Minister responsible for energy, after consultation with an advisory committee made up of representatives of the Ministries concerned (NEA) [fr

Application of U.S. export controls to DOE technical exchanges: New guidelines on export control and nonproliferation

International Nuclear Information System (INIS)

Lisann, E.G.; Hollander, Z.; Rudolph, R.R.

1995-01-01

As the Department of Energy's nuclear weapon's complex shrinks, concern regarding the proliferation of nuclear weapons technology through the release of export-controlled equipment, materials and information has come to the fore. In November, 1994 Under Secretary Charles Curtis issued new guidelines on export control and nonproliferation. The new policies and procedures are designed to help Department of Energy Headquarters Offices, Operations Offices, Area Offices, laboratories and contractors implement a consistent and technologically sound policy regarding DOE transfers of unclassified equipment, materials and information that could adversely affect US nuclear nonproliferation objectives or national security. The DOE Export Control Division has developed a multi-faceted program of guidelines and training materials to sensitize DOE and DOE-contractors to their responsibilities and to teach them how to evaluate the proliferation risks of their activities

Shape analysis of single and stacked InAs quantum dots at the atomic level by cross-sectional STM

NARCIS (Netherlands)

Bruls, D.M.; Vugs, J.W.A.M.; Koenraad, P.M.; Skolnick, M.S.; Hopkinson, M.; Wolter, J.H.; Miura, N.; Ando, T.

2001-01-01

We present a study of InAs self-assembled quantum dots in GaAs by cross-sectional scanning tunneling microscopy (X-STM). Our results shows that the dots consist of an JnGaAs alloy and that the indium content increases towards the top. The analysis of the height versus base length relation obtained

InAs quantum dot growth on Al{sub x}Ga{sub 1−x}As by metalorganic vapor phase epitaxy for intermediate band solar cells

Energy Technology Data Exchange (ETDEWEB)

Jakomin, R., E-mail: robertojakomin@xerem.ufrj.br [Campus de Xerém, Universidade Federal do Rio de Janeiro, UFRJ, Duque de Caxias-RJ (Brazil); Campus de Xerém, Universidade Federal do Rio de Janeiro, UFRJ, Duque de Caxias-RJ (Brazil); Kawabata, R. M. S.; Souza, P. L. [Instituto Nacional de Ciência e Tecnologia de Nanodispositivos Semicondutoires–DISSE–PUC-Rio, RJ (Brazil); Pontificia Universidade Católica do Rio de Janeiro, Marques de São Vicente 225, Rio de Janeiro, 22452-900 RJ (Brazil); Mourão, R. T.; Pires, M. P. [Instituto Nacional de Ciência e Tecnologia de Nanodispositivos Semicondutoires–DISSE–PUC-Rio, RJ (Brazil); Instituto de Física, Universidade Federal do Rio de Janeiro, UFRJ, Rio de Janeiro-RJ (Brazil); Micha, D. N. [Instituto Nacional de Ciência e Tecnologia de Nanodispositivos Semicondutoires–DISSE–PUC-Rio, RJ (Brazil); Instituto de Física, Universidade Federal do Rio de Janeiro, UFRJ, Rio de Janeiro-RJ (Brazil); Coordenação de Licenciatura em Física, CEFET/RJ, Petrópolis-RJ (Brazil); Xie, H.; Fischer, A. M.; Ponce, F. A. [Department of Physics, Arizona State University, Tempe, Arizona 85287-1504 (United States)

2014-09-07

InAs quantum dot multilayers have been grown using Al{sub x}Ga{sub 1−x}As spacers with dimensions and compositions near the theoretical values for optimized efficiencies in intermediate band photovoltaic cells. Using an aluminium composition of x = 0.3 and InAs dot vertical dimensions of 5 nm, transitions to an intermediate band with energy close to the ideal theoretical value have been obtained. Optimum size uniformity and density have been achieved by capping the quantum dots with GaAs following the indium-flush method. This approach has also resulted in minimization of crystalline defects in the epilayer structure.

Solução concentrada de albumina eqüina na fluidoterapia em eqüinos com desidratação leve a moderada

OpenAIRE

Belli,C.B.; Michima,L.E.S.; Latorre,S.M.; Fernandes,W.R.

2008-01-01

Avaliou-se o efeito da solução concentrada de albumina eqüina diluída a 5% em solução fisiológica (SF) durante fluidoterapia em eqüinos, após indução de desidratação leve a moderada, utilizando-se cinco eqüinos adultos, sem alterações clínicas. Cada animal passou por dois protocolos de fluidoterapia: apenas com SF (metade sob pressão e metade em fluxo contínuo - grupo-controle); com solução de albumina eqüina e SF (apenas em fluxo contínuo - grupo experimental). Avaliaram-se peso, exame físic...

Transparency and nonproliferation in the Asia-Pacific region. Enhancing transparency, strengthening the nonproliferation regime

International Nuclear Information System (INIS)

Hamada, Kazuko

2008-01-01

Driven by the prospect of rapid economic growth and the perceived need for energy security, the Asia-Pacific region is destined to increase its nuclear energy use in the coming decades. This projected increase, however, will bring with it nuclear proliferation concerns, fueling fears about the security of nuclear material and creating suspicions about its use. The increasing use of nuclear energy inevitably necessitates supplementary efforts, designed to ensure nuclear security and a legitimate use of nuclear energy, other than the obligation to the Treaty on the Nonproliferation of Nuclear Weapons (NPT). Nuclear transparency measures could be useful tools for building confidence that the increasing nuclear energy use does not contribute to nuclear proliferation. These measures could also foster a cooperative tradition that can address rising concerns over nuclear trafficking and terrorism, which require regional coordination to combat. However, moderate progress in implementing transparency measures suggests a lack of political appreciation of this concept. Thus, this paper describes various forms of potential transparency measures to expand the possibilities of the transparency concept and explore areas in which this concept might be applicable. This paper also clarifies some challenges involving transparency projects, and suggests possible ways to address these challenges. (author)

The crisis bears the chance. The nuclear conflict with Iran and the impact on the nuclear non-proliferation regime; In der Krise liegt die Chance. Der Atomkonflikt mit Iran und seine Auswirkungen auf das nukleare Nichtverbreitungsregime

Energy Technology Data Exchange (ETDEWEB)

Meier, Oliver

2014-10-15

The contribution on the nuclear conflict with Iran and the impact on the nuclear non-proliferation regime covers the following topics: Iran and the verification of non-nuclear -weapon states, the system of nuclear safeguards, the application of new verification instruments, verification of possible military research and development activities, the limitation of proliferation relevant activities, delivery guarantees as mean for non-proliferation, Iran and the handling of contract violations, graded reactions, political issues, problems of harmonization, capacity and process deficiencies, before the ninth non-proliferation verification conference, approaches for strengthening the non-proliferation regime, recommendation to the German politics.

Nuclear weapon-free zone, non-proliferation treaty and South Asia

International Nuclear Information System (INIS)

Jayaramu, P.S.

1980-01-01

Emergence of and the motivations behind the concept of nuclear weapon free zone, the conceptual linkage between the nuclear weapon free zone and the Non-Proliferation Treaty and the problems involved in the implementation of nuclear weapon free zone proposals put forward from time to time are discussed. Pakistan's proposal for a nuclear weapon free zone in South Asia, motivations behind the proposal, and India's response to it are examined. It is pointed out that both the NPT and nuclear weapon free zone indirectly grant a certain amount of legitimacy to the use of nuclear weapons. (M.G.B.)

Implementing nuclear non-proliferation in Finland. Regulatory control, international cooperation and the Comprehensive Nuclear-Test-Ban Treaty. Annual report 2011

Energy Technology Data Exchange (ETDEWEB)

Okko, O [ed.

2012-07-01

The regulatory control of nuclear materials (i.e. nuclear safeguards) is a prerequisite for the peaceful use of nuclear energy in Finland. Safeguards are required for Finland to comply with international agreements on nuclear non-proliferation - mainly the Non-Proliferation Treaty (NPT). This regulatory control is exercised by the Nuclear Materials Section of the Finnish Radiation and Nuclear Safety Authority (STUK). The results of STUK's nuclear safeguards inspection activities in 2011 continued to demonstrate that the Finnish licence holders take good care of their nuclear materials. There were no indications of undeclared nuclear materials or activities and the inspected materials and activities were in accordance with the licence holders' declarations.

ISTRAŽIVANJE ZAGAĐENOSTI MESA, RADNIH POVRŠINA I PRIBORA BAKTERIJAMA RODA PROTEUS

OpenAIRE

Hadžiosmanović, Mirza; Živković, Josip; Trešćec, Aida

1992-01-01

Istraživan je stupanj zagađenja sirovina i radnih površina tijekom proizvodnje mesnih prerađevina bakterijama roda Proteus. Rezultati su pokazali da je meso peradi zagađeno vrstama roda Proteus u količini od 8,8%, svježe goveđe meso 7,8 % a polutrajne i obarene kobasice neposredno nakon proizvoodnje u količini od 2,8 %. Rezultati pretraga brisova s proizvodnih linija pokazuju da je pripadnika roda Proteus najviše u kobasičarnici (14,6 %), na liniji prerade svinja (11,8 %), goveda (10,9 %), a ...

The investigation of alloy formation during InAs nanowires growth on GaAs (111)B substrate

Energy Technology Data Exchange (ETDEWEB)

Saqib, Muhammad; Biermanns, Andreas; Davydok, Anton; Pietsch, Ullrich [Festkoerperphysik, Universitaet Siegen, Walter-Flex-Str. 3, Siegen 57072 (Germany); Rieger, Torsten; Grap, Thomas; Lepsa, Mihail [Peter Gruenberg Institute (PGI-9), Forschungzentrum Juelich, Juelich 52425 (Germany)

2013-07-01

A possible way to obtain nanowires is the growth in molecular beam epitaxy (MBE) on the (111) oriented surface of the desired substrate, covered by a thin oxide layer. A crucial parameter in this method is the initial thickness of the oxide layer, often determined by an etching procedure. In this contribution, we report on the structural investigation of two different series (etched and unetched) of NWs samples. Vertically aligned InAs nanowires (NWs) doped with Si were self-assisted grown by molecular beam epitaxy on GaAs [111]B substrates covered with a thin SiO{sub x} layer. Using a combination of symmetric and asymmetric X-ray diffraction we study the influence of Si supply on the growth process and nanostructure formation. We find that the number of parasitic crystallites grown between the NWs increases with increasing Si flux. In addition, we observe the formation of a Ga{sub 0.2}In{sub 0.8}As alloy if the growth is performed on samples covered by a defective (etched) oxide layer. This alloy formation is observed within the crystallites and not within the nanowires. The Gallium concentration is determined from the lattice mismatch of the crystallites relative to the InAs nanowires. No alloy formation is found for samples with faultless oxide layers.

The influence of atmosphere on performance of pure-phase WZ and ZB InAs nanowire transistors.

Science.gov (United States)

Ullah, Abu Rifat; Joyce, Hannah J; Tan, Hoe; Jagadish, Chennupati; Micolich, Adam P

2017-09-21

We compare the characteristics of phase-pure MOCVD grown ZB and WZ InAs nanowire transistors in several atmospheres: air, dry pure N₂ and O₂, and N₂ bubbled through liquid H₂O and alcohols to identify whether phase-related structural/surface differences affect their response. Both WZ and ZB give poor gate characteristics in dry state. Adsorption of polar species reduces off-current by 2-3 orders of magnitude, increases on-off ratio and significantly reduces sub-threshold slope. The key difference is the greater sensitivity of WZ to low adsorbate level. We attribute this to facet structure and its influence on the separation between conduction electrons and surface adsorption sites. We highlight the important role adsorbed species play in nanowire device characterisation. WZ is commonly thought superior to ZB in InAs nanowire transistors. We show this is an artefact of the moderate humidity found in ambient laboratory conditions: WZ and ZB perform equally poorly in the dry gas limit yet equally well in the wet gas limit. We also highlight the vital role density-lowering disorder has in improving gate characteristics, be it stacking faults in mixed-phase WZ or surface adsorbates in pure-phase nanowires. © 2017 IOP Publishing Ltd.

Course modules on nuclear safeguards and non-proliferation

International Nuclear Information System (INIS)

Bril, L.-V.; Janssens-Maenhout, G.

2004-01-01

Full text: One of major current concern in the nuclear field is the conservation of developed knowledge and expertise. The relevance of this subject is steadily increasing for several reasons: retirement of the generation of first industrial development of nuclear energy, only one new reactor under construction in Europe while several in Eastern and Asian countries, the public's concern on safety, radioactive waste and safeguards aspects, and some lack of interest common to many activities in engineering and physics. Moreover nuclear safeguards is nowadays characterised with an enlarged scope and no longer strictly limited to the accountancy of nuclear material; today it encompasses non proliferation of nuclear material, and deals with the control of dual use equipment and technologies, illicit trafficking and External Security. Some higher education networks, such as the European Nuclear Engineering Network (ENEN), have been established to make better use of dwindling teaching capacity, scientific equipment and research infrastructure, through co-operation amongst universities and research centres. The European Safeguards Research and Development Association (ESARDA) initiated the set-up of course modules under an e-learning medium, to preserve knowledge in nuclear safeguards. These course modules should be considered as basic pedagogical documentation, which will be accessible via the Internet. Monitoring or controlling of the accesses will be ensured. The modules are structured with an increasing level of detail, in function of the audience. On one hand the course modules should be attractive to University students in nuclear, chemical or mechanical engineering, in radiochemistry, statistics, law, political science etc. at universities or specialised institutes. On the other hand the course modules aim to give professionals, working on specific safeguards or non-proliferation issues an overview and detailed technical information on the wide variety of nuclear

Electronic properties of GaAs, InAs and InP nanowires studied by terahertz spectroscopy

International Nuclear Information System (INIS)

Joyce, Hannah J; Docherty, Callum J; Lloyd-Hughes, James; Herz, Laura M; Johnston, Michael B; Gao Qiang; Tan, H Hoe; Jagadish, Chennupati

2013-01-01

We have performed a comparative study of ultrafast charge carrier dynamics in a range of III–V nanowires using optical pump–terahertz probe spectroscopy. This versatile technique allows measurement of important parameters for device applications, including carrier lifetimes, surface recombination velocities, carrier mobilities and donor doping levels. GaAs, InAs and InP nanowires of varying diameters were measured. For all samples, the electronic response was dominated by a pronounced surface plasmon mode. Of the three nanowire materials, InAs nanowires exhibited the highest electron mobilities of 6000 cm 2 V −1 s −1 , which highlights their potential for high mobility applications, such as field effect transistors. InP nanowires exhibited the longest carrier lifetimes and the lowest surface recombination velocity of 170 cm s −1 . This very low surface recombination velocity makes InP nanowires suitable for applications where carrier lifetime is crucial, such as in photovoltaics. In contrast, the carrier lifetimes in GaAs nanowires were extremely short, of the order of picoseconds, due to the high surface recombination velocity, which was measured as 5.4 × 10 5   cm s −1 . These findings will assist in the choice of nanowires for different applications, and identify the challenges in producing nanowires suitable for future electronic and optoelectronic devices. (paper)

Ballistic One-Dimensional InAs Nanowire Cross-Junction Interconnects.

Science.gov (United States)

Gooth, Johannes; Borg, Mattias; Schmid, Heinz; Schaller, Vanessa; Wirths, Stephan; Moselund, Kirsten; Luisier, Mathieu; Karg, Siegfried; Riel, Heike

2017-04-12

Coherent interconnection of quantum bits remains an ongoing challenge in quantum information technology. Envisioned hardware to achieve this goal is based on semiconductor nanowire (NW) circuits, comprising individual NW devices that are linked through ballistic interconnects. However, maintaining the sensitive ballistic conduction and confinement conditions across NW intersections is a nontrivial problem. Here, we go beyond the characterization of a single NW device and demonstrate ballistic one-dimensional (1D) quantum transport in InAs NW cross-junctions, monolithically integrated on Si. Characteristic 1D conductance plateaus are resolved in field-effect measurements across up to four NW-junctions in series. The 1D ballistic transport and sub-band splitting is preserved for both crossing-directions. We show that the 1D modes of a single injection terminal can be distributed into multiple NW branches. We believe that NW cross-junctions are well-suited as cross-directional communication links for the reliable transfer of quantum information as required for quantum computational systems.

A Brief History of INA and ICOH SCNP: International Neurotoxicology Association and International Congress on Occupational Health Scientific Committee on Neurotoxicology and Psychophysiology

Science.gov (United States)

Two international scientific societies dedicated to research in neurotoxicology and neurobehavioral toxicology are the International Neurotoxicology Association (INA) and the International Congress on Occupational Health International Symposium on Neurobehavioral Methods and Effe...

Surface roughness induced electron mobility degradation in InAs nanowires

International Nuclear Information System (INIS)

Wang Fengyun; Yip, Sen Po; Han, Ning; Fok, KitWa; Lin, Hao; Hou, Jared J; Dong, Guofa; Hung, Tak Fu; Chan, K S; Ho, Johnny C

2013-01-01

In this work, we present a study of the surface roughness dependent electron mobility in InAs nanowires grown by the nickel-catalyzed chemical vapor deposition method. These nanowires have good crystallinity, well-controlled surface morphology without any surface coating or tapering and an excellent peak field-effect mobility up to 15 000 cm 2 V −1 s −1 when configured into back-gated field-effect nanowire transistors. Detailed electrical characterizations reveal that the electron mobility degrades monotonically with increasing surface roughness and diameter scaling, while low-temperature measurements further decouple the effects of surface/interface traps and phonon scattering, highlighting the dominant impact of surface roughness scattering on the electron mobility for miniaturized and surface disordered nanowires. All these factors suggest that careful consideration of nanowire geometries and surface condition is required for designing devices with optimal performance. (paper)

Flaws in the Non-Proliferation Treaty

International Nuclear Information System (INIS)

Leventhal, P.

1986-01-01

The Treaty on the Non-Proliferation of Nucler Weapons has the twin objectives of stopping the further spread of nuclear weapons and ending the nuclear arms race on the one hand, and promoting peaceful uses of atomic energy on the other. In quantitative and symbolic terms the NPT is a huge success. More than two-thirds of the world's nations have signed on, making this the most popular arms control agreement on earth. Not a single nation has declared itself to be a nuclear-weapons state beyond the original five members of the ''nuclear club'' who qualified for weapons status under the terms of the Treaty itself: the United States, the Soviet Union, the United Kingdom, France, and China. No party to the Treaty has exercised the permitted option to drop out, and none has been found by the International Atomic Energy Agency (IAEA) to have diverted nuclear material from civil to weapons purposes. Nor has any party been known to have violated NPT prohibitions on developing or assisting other nations to develop nuclear weapons

Treaty on the non-proliferation of nuclear weapons: Review conference of the States Parties Geneva 1985

International Nuclear Information System (INIS)

1984-01-01

The Third Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons will be held in Geneva, Switzerland, in 1985 with a view to assuring that the purposes and provisions of the Treaty are being realized. The Treaty, commonly referred to as the non-proliferation Treaty, is the fundamental instrument to avert the danger of proliferation of nuclear weapons and is, perhaps, the most important multilateral arms regulation agreement of our time. It was negotiated in the 1960s in the Eighteen-Nation Committee on Disarmament in Geneva and in the United Nations General Assembly. The Treaty was opened for signature in London, Moscow and Washington on July 1, 1968. On that date, it was signed by the three Depositary Governments - the Soviet Union, the United Kingdom and the United States - and by 58 other States. As of December 31, 1983 the number of States parties to the Treaty had risen to 119

ANALYSIS OF INA-CBG’S FARE AND GOVERNOR REGULATION FAREON SURGERY AT INPATIENT ROOM OF UNDATA REGIONAL PUBLIC HOSPITAL IN PALU

Directory of Open Access Journals (Sweden)

Muh. Ryman Napirah

2016-03-01

Full Text Available Aim: In order to determine the fares of surgery, there are two types of fares used by hospitals namely Indonesian Case Based Groups fare (INA-CBG s and Governor Regulation fare. This study aimed to identify and analyze both types of fares in orthopedic surgery, general, eyes, midwifery, mouth, ENT, urology at inpatient room of Undata Regional Public Hospital in Palu during year 2014. Method: This was a quantitative study with descriptive approach with 46 cases as the number of surgery. Data were collected through observation and analysis of secondary data were gotten from medical record, pharmaceutical installation of IBS/IDR, inpatient therapy room (Matahari, Aster, and Teratai pavilions and cashier of inpatient room in form of cost details and patient data from January to December 2014. Data Presentation was formed on tables, where the existing fares are grouped based on the component of each cost then summed and calculated the deviation between the two types of fares. Results: This study indicated that orthopedic surgery with deviation of Rp 11.311.365, general surgery with deviation of Rp 6.438.409, eyes surgery with deviation of Rp 45.173.741, midwifery surgery with deviation of Rp 6.645.765, oral surgery with deviation of Rp 6.105.659, and urological surgery with deviation of Rp. 3.809.959. Conclusion: It can be concluded that INA-CBG's fares are higher than Governor Regulation fares except orthopedic surgery, where the Governor Regulation faresare higher than INA-CBG’s fares.