Surface and Flow Field Measurements on the FAITH Hill Model

Science.gov (United States)

Bell, James H.; Heineck, James T.; Zilliac, Gregory; Mehta, Rabindra D.; Long, Kurtis R.

2012-01-01

A series of experimental tests, using both qualitative and quantitative techniques, were conducted to characterize both surface and off-surface flow characteristics of an axisymmetric, modified-cosine-shaped, wall-mounted hill named "FAITH" (Fundamental Aero Investigates The Hill). Two separate models were employed: a 6" high, 18" base diameter machined aluminum model that was used for wind tunnel tests and a smaller scale (2" high, 6" base diameter) sintered nylon version that was used in the water channel facility. Wind tunnel and water channel tests were conducted at mean test section speeds of 165 fps (Reynolds Number based on height = 500,000) and 0.1 fps (Reynolds Number of 1000), respectively. The ratio of model height to boundary later height was approximately 3 for both tests. Qualitative techniques that were employed to characterize the complex flow included surface oil flow visualization for the wind tunnel tests, and dye injection for the water channel tests. Quantitative techniques that were employed to characterize the flow included Cobra Probe to determine point-wise steady and unsteady 3D velocities, Particle Image Velocimetry (PIV) to determine 3D velocities and turbulence statistics along specified planes, Pressure Sensitive Paint (PSP) to determine mean surface pressures, and Fringe Imaging Skin Friction (FISF) to determine surface skin friction (magnitude and direction). This initial report summarizes the experimental set-up, techniques used, data acquired and describes some details of the dataset that is being constructed for use by other researchers, especially the CFD community. Subsequent reports will discuss the data and their interpretation in more detail

Tunneling times and the Hartman effect revisited

International Nuclear Information System (INIS)

Olkhovsky, Vladislav S.; Recami, Erasmo; Raciti, Fabio

1995-05-01

In a recent review paper we proposed, within conventional quantum mechanics, new definitions for the sub-barrier tunnelling and reflection times. Aims of the present paper are: presenting and analysing the results of various numerical calculations (based on our equations) on the penetration and return times , , during tunneling inside a rectangular potential barrier, for various penetration depths x f ; putting forth and discussing suitable definitions, besides of the mean values, also of the variances (or dispersions) D τ T D τ R for the time durations of transmission and reflection process; mentioning that our definition τ T > for the average transmission time results to constitute an improvement of the ordinary dwell-time τ Dw formula; commenting upon some recent criticism by C.R. Leavens, on the basis of our new numerical results. We stress that our numerical evaluations confirm that our approach implied and implies, the existence of the Hartman effect: an effect that in these days (due to the theoretical connections between tunneling and evanescent wave propagation) is receiving - at Cologne, Berkeley, Florence and Vienna- indirect, but quite interesting, experimental verifications. At last, we briefly analyze some other definitions of tunnelling times. (author). 24 refs., 5 figs

Berkeley mini-collider

International Nuclear Information System (INIS)

Schroeder, L.S.

1984-06-01

The Berkeley Mini-Collider, a heavy-ion collider being planned to provide uranium-uranium collisions at T/sub cm/ less than or equal to 4 GeV/nucleon, is described. The central physics to be studied at these energies and our early ideas for a collider detector are presented

Tunneling times and the Hartman effect revisited

Energy Technology Data Exchange (ETDEWEB)

Olkhovsky, Vladislav S. [Ukrainian Academy of Sciences, Kiev (Ukraine). Inst. for Nuclear Research]|[Istituto Nazionale di Fisica Nucleare, Catania (Italy); Recami, Erasmo [Universidade Estadual de Campinas, SP (Brazil). Dept. de Matematica Aplicada]|[Istituto Nazionale di Fisica Nucleare, Milano (Italy); Raciti, Fabio [Catania Univ. (Italy). Dipt. di Fisica; Zaichenko, Aleksandr K. [Ukrainian Academy of Sciences, Kiev (Ukraine)

1995-05-01

In a recent review paper we proposed, within conventional quantum mechanics, new definitions for the sub-barrier tunnelling and reflection times. Aims of the present paper are: presenting and analysing the results of various numerical calculations (based on our equations) on the penetration and return times < {tau}Pen >, <{tau}Ret >, during tunneling inside a rectangular potential barrier, for various penetration depths x{sub f}; putting forth and discussing suitable definitions, besides of the mean values, also of the variances (or dispersions) D {sup {tau}}T D {sup {tau}}R for the time durations of transmission and reflection process; mentioning that our definition < {sup {tau}}T > for the average transmission time results to constitute an improvement of the ordinary dwell-time {tau}{sup Dw} formula; commenting upon some recent criticism by C.R. Leavens, on the basis of our new numerical results. We stress that our numerical evaluations confirm that our approach implied and implies, the existence of the Hartman effect: an effect that in these days (due to the theoretical connections between tunneling and evanescent wave propagation) is receiving - at Cologne, Berkeley, Florence and Vienna- indirect, but quite interesting, experimental verifications. At last, we briefly analyze some other definitions of tunnelling times. (author). 24 refs., 5 figs.

City of Berkeley, California Municipal Tree Resource Analysis

Science.gov (United States)

S.E. Maco; E.G. McPherson; J.R. Simpson; P.J. Peper; Q. Xiao

2005-01-01

Vibrant, renowned for its livability and cultural wealth, the city of Berkeley maintains trees as an integral component of the urban infrastructure. Research indicates that healthy trees can mitigate impacts associated with the built environment by reducing stormwater runoff, energy consumption, and air pollutants. Put simply, trees improve urban life, making Berkeley...

Environmental Survey preliminary report, Lawrence Berkeley Laboratory, Berkeley, California

International Nuclear Information System (INIS)

1988-07-01

The purpose of this report is to present the preliminary findings made during the Environmental Survey, February 22--29, 1988, at the US Department of Energy (DOE) Lawrence Berkeley Laboratory (LBL) in Berkeley, California. The University of California operates the LBL facility for DOE. The LBL Survey is part of the larger DOE-wide Environmental Survey announced by Secretary John S. Herrington on September 18, 1985. The purpose of this effort is to identify, via ''no fault'' baseline Surveys, existing environmental problems and areas of environmental risk at DOE facilities, and to rank them on a DOE wide basis. This ranking will enable DOE to more effectively establish priorities for addressing environmental problems and allocate the resources necessary to correct them. Because the Survey is ''no fault'' and is not an ''audit,'' it is not designed to identify specific isolated incidents of noncompliance or to analyze environmental management practices. Such incidents and/or management practices will, however, be used in the Survey as a means of identifying existing and potential environmental problems. The LBL Survey was conducted by a multidisciplinary team of technical specialists headed and managed by a Team Leader and Assistant Team Leader from DOE's Office of Environmental Audit. A complete list of the LBL Survey participants and their affiliations is provided in Appendix A. 80 refs., 27 figs., 37 tabs

Environmental Survey preliminary report, Lawrence Berkeley Laboratory, Berkeley, California

Energy Technology Data Exchange (ETDEWEB)

1988-07-01

The purpose of this report is to present the preliminary findings made during the Environmental Survey, February 22--29, 1988, at the US Department of Energy (DOE) Lawrence Berkeley Laboratory (LBL) in Berkeley, California. The University of California operates the LBL facility for DOE. The LBL Survey is part of the larger DOE-wide Environmental Survey announced by Secretary John S. Herrington on September 18, 1985. The purpose of this effort is to identify, via no fault'' baseline Surveys, existing environmental problems and areas of environmental risk at DOE facilities, and to rank them on a DOE wide basis. This ranking will enable DOE to more effectively establish priorities for addressing environmental problems and allocate the resources necessary to correct them. Because the Survey is no fault'' and is not an audit,'' it is not designed to identify specific isolated incidents of noncompliance or to analyze environmental management practices. Such incidents and/or management practices will, however, be used in the Survey as a means of identifying existing and potential environmental problems. The LBL Survey was conducted by a multidisciplinary team of technical specialists headed and managed by a Team Leader and Assistant Team Leader from DOE's Office of Environmental Audit. A complete list of the LBL Survey participants and their affiliations is provided in Appendix A. 80 refs., 27 figs., 37 tabs.

Evaluating the Impact of Open Access at Berkeley: Results from the 2015 Survey of Berkeley Research Impact Initiative (BRII) Funding Recipients

Science.gov (United States)

Teplitzky, Samantha; Phillips, Margaret

2016-01-01

The Berkeley Research Impact Initiative (BRII) was one of the first campus-based open access (OA) funds to be established in North America and one of the most active, distributing more than $244,000 to support University of California (UC) Berkeley authors. In April 2015, we conducted a qualitative study of 138 individuals who had received BRII…

Berkeley Lab Laser Accelerator (BELLA) facility

Data.gov (United States)

Federal Laboratory Consortium — The Berkeley Lab Laser Accelerator (BELLA) facility (formerly LOASIS) develops advanced accelerators and radiation sources. High gradient (1-100 GV/m) laser-plasma...

Experimental and Numerical Modelling of Flow over Complex Terrain: The Bolund Hill

Science.gov (United States)

Conan, Boris; Chaudhari, Ashvinkumar; Aubrun, Sandrine; van Beeck, Jeroen; Hämäläinen, Jari; Hellsten, Antti

2016-02-01

In the wind-energy sector, wind-power forecasting, turbine siting, and turbine-design selection are all highly dependent on a precise evaluation of atmospheric wind conditions. On-site measurements provide reliable data; however, in complex terrain and at the scale of a wind farm, local measurements may be insufficient for a detailed site description. On highly variable terrain, numerical models are commonly used but still constitute a challenge regarding simulation and interpretation. We propose a joint state-of-the-art study of two approaches to modelling atmospheric flow over the Bolund hill: a wind-tunnel test and a large-eddy simulation (LES). The approach has the particularity of describing both methods in parallel in order to highlight their similarities and differences. The work provides a first detailed comparison between field measurements, wind-tunnel experiments and numerical simulations. The systematic and quantitative approach used for the comparison contributes to a better understanding of the strengths and weaknesses of each model and, therefore, to their enhancement. Despite fundamental modelling differences, both techniques result in only a 5 % difference in the mean wind speed and 15 % in the turbulent kinetic energy (TKE). The joint comparison makes it possible to identify the most difficult features to model: the near-ground flow and the wake of the hill. When compared to field data, both models reach 11 % error for the mean wind speed, which is close to the best performance reported in the literature. For the TKE, a great improvement is found using the LES model compared to previous studies (20 % error). Wind-tunnel results are in the low range of error when compared to experiments reported previously (40 % error). This comparison highlights the potential of such approaches and gives directions for the improvement of complex flow modelling.

THE YOUNG OPEN CLUSTER BERKELEY 55

Energy Technology Data Exchange (ETDEWEB)

Negueruela, Ignacio; Marco, Amparo, E-mail: ignacio.negueruela@ua.es, E-mail: amparo.marco@ua.es [Departamento de Fisica, Ingenieria de Sistemas y Teoria de la Senal, Universidad de Alicante, Apdo. 99, E-03080 Alicante (Spain)

2012-02-15

We present UBV photometry of the highly reddened and poorly studied open cluster Berkeley 55, revealing an important population of B-type stars and several evolved stars of high luminosity. Intermediate-resolution far-red spectra of several candidate members confirm the presence of one F-type supergiant and six late supergiants or bright giants. The brightest blue stars are mid-B giants. Spectroscopic and photometric analyses indicate an age 50 {+-} 10 Myr. The cluster is located at a distance d Almost-Equal-To 4 kpc, consistent with other tracers of the Perseus Arm in this direction. Berkeley 55 is thus a moderately young open cluster with a sizable population of candidate red (super)giant members, which can provide valuable information about the evolution of intermediate-mass stars.

The East Bay Vegetation Management Consortium:\\ta subregional approach to resource management and planning

Science.gov (United States)

Tony Acosta

1995-01-01

Formed in response to the October 20, 1991, Oakland/Berkeley hills firestorm, the East Bay Vegetation Management Consortium (EBVMC) is a voluntary association of public agencies concerned with vegetation management and planning related to fire hazard reduction in the Oakland/ Berkeley hills. To date, a total of nine agencies are participating in the EBVMC, including...

Parks of Chapel Hill

Data.gov (United States)

Town of Chapel Hill, North Carolina — Hours, location, and amenity information for Chapel Hill parks as shown on the Town of Chapel Hill's website. Includes a map with points for each park location.

George Berkeley e a tradição platônica

Directory of Open Access Journals (Sweden)

Costica Bradatan

2009-12-01

Full Text Available Existe já uma grande quantidade de literatura dedicada à presença na filosofia inicial de Berkeley de alguns assuntos tipicamente platônicos (arquétipos, o problema da mente de Deus, a relação entre ideias e coisas, etc.. Baseados em alguns desses escritos, nas próprias palavras de Berkeley, assim como no exame de alguns elementos da tradição platônica num amplo sentido, sugiro que, longe de serem apenas tópicos isolados, livremente espalhados nos primeiros escritos de Berkeley, eles formam uma perfeita rede de aspectos, atitudes e modos de pensar platônicos, e que, por mais alusivos ou ambíguos que esses elementos platônicos possam parecer, eles constituem um todo coerente e complexo, desempenhando um papel importante na formação da própria essência do pensamento de Berkeley. Em outras palavras, sugiro que, dadas algumas das ideias apresentadas em suas primeiras obras, foi de certo modo inevitável para George Berkeley, em virtude da lógica interna do desenvolvimento de seu pensamento, chegar a uma obra tão abertamente platônica e especulativa como Siris (1744.

Tunnels: different construction methods and its use for pipelines installation

Energy Technology Data Exchange (ETDEWEB)

Mattos, Tales; Soares, Ana Cecilia; Assis, Slow de; Bolsonaro, Ralfo; Sanandres, Simon [Petroleo do Brasil S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

2009-07-01

In a continental dimensions country like Brazil, the pipeline modal faces the challenge of opening ROW's in the most different kind of soils with the most different geomorphology. To safely fulfill the pipeline construction demand, the ROW opening uses all techniques in earthworks and route definition and, where is necessary, no digging techniques like horizontal directional drilling, micro tunneling and also full size tunnels design for pipelines installation in high topography terrains to avoid geotechnical risks. PETROBRAS has already used the tunnel technique to cross higher terrains with great construction difficult, and mainly to make it pipeline maintenance and operation easier. For the GASBOL Project, in Aparados da Serra region and in GASYRG, in Bolivia, two tunnels were opened with approximately 700 meters and 2,000 meters each one. The GASBOL Project had the particularity of being a gallery with only one excavation face, finishing under the hill and from this point was drilled a vertical shaft was drilled until the top to install the pipeline section, while in GASYRG Project the tunnel had two excavation faces. Currently, two projects are under development with tunnels, one of then is the Caraguatatuba-Taubate gas pipeline (GASTAU), with a 5 km tunnel, with the same concepts of the GASBOL tunnel, with a gallery to be opened with the use of a TBM (Tunneling Boring Machine), and a shaft to the surface, and the gas pipeline Cabiunas-Reduc III (GASDUC III) project is under construction with a 3.7 km tunnel, like the GASYRG tunnel with two faces. This paper presents the main excavation tunneling methods, conventional and mechanized, presenting the most relevant characteristics from both and, in particular, the use of tunnels for pipelines installation. (author)

Political-social reactor problems at Berkeley

International Nuclear Information System (INIS)

Little, G.A.

1980-01-01

For better than ten years there was little public notice of the TRIGA reactor at UC-Berkeley. Then: a) A non-student persuaded the Student and Senate to pass a resolution to request Campus Administration to stop operation of the reactor and remove it from campus. b) Presence of the reactor became a campaign-issue in a City Mayoral election. c) Two local residents reported adverse physical reactions before, during, and after a routine tour of the reactor facility. d) The Berkeley City Council began a study of problems associated with radioactive material within the city. e) Friends Of The Earth formally petitioned the NRC to terminate the reactor's license. Campus personnel have expended many man-hours and many pounds of paper in responding to these happenings. Some of the details are of interest, and may be of use to other reactor facilities. (author)

Petrology and geochemistry of samples from bed-contact zones in Tunnel Bed 5, U12g-Tunnel, Nevada Test Site

International Nuclear Information System (INIS)

Connolly, J.R.; Keil, K.; Mansker, W.L.; Allen, C.C.; Husler, J.; Lowy, R.; Fortney, D.R.; Lappin, A.R.

1984-10-01

This report summarizes the detailed geologic characterization of samples of bed-contact zones and surrounding nonwelded bedded tuffs, both within Tunnel Bed 5, that are exposed in the G-Tunnel complex beneath Rainier Mesa on the Nevada Test Site (NTS). Original planning studies treated the bed-contact zones in Tunnel Bed 5 as simple planar surfaces of relatively high permeability. Detailed characterization, however, indicates that these zones have a finite thickness, are depositional in origin, vary considerably over short vertical and horizontal distances, and are internally complex. Fluid flow in a sequence of nonwelded zeolitized ash-flow or bedded tuffs and thin intervening reworked zones appears to be a porous-medium phenomenon, regardless of the presence of layering. There are no consistent differences in either bulk composition or detailed mineralogy between bedded tuffs and bed-contact zones in Tunnel Bed 5. Although the original bulk composition of Tunnel Bed 5 was probably peralkaline, extensive zeolitization has resulted in a present peraluminous bulk composition of both bedded tuffs and bed-contact zones. The major zeolite present, clinoptilolite, is intermediate (Ca:K:Na = 26:35:39) and effectively uniform in composition. This composition is similar to that of clinoptilolite from the tuffaceous beds of Calico Hills above the static water level in hole USW G-1, but somewhat different from that reported for zeolites from below the static water level in USW G-2. Tunnel Bed 5 also contains abundant hydrous manganese oxides. The similarity in composition of the clinoptilolites from Tunnel Bed 5 and those above the static water level at Yucca Mountain indicates that many of the results of nuclide-migration experiments in Tunnel Bed 5 would be transferrable to zeolitized nonwelded tuffs above the static water level at Yucca Mountain

Power Management Controls, Ernest Orlando Lawrence Berkeley National Laboratory; Power Management Controls, Ernest Orlando Lawrence Berkeley National Laboratory

Energy Technology Data Exchange (ETDEWEB)

Westerberg, Emil [Dalarna Univ., Borlaenge (Sweden). Graphic Art Technology

2002-12-01

This report describes the work that is being conducted on power management controls at Berkeley National Laboratory. We can see a significant increasing amount of electronic equipment in our work places and in our every day life. Today's modern society depends on a constant energy flow. The future's increasing need of energy will burden our economy as well as our environment. The project group at Berkeley National Laboratory is working with leading manufacturers of office equipment. The goal is to agree on how interfaces for power management should be presented on office equipment. User friendliness and a more consistent power management interface is the project focus. The project group's role is to analyze data that is relevant to power management, as well as to coordinate communication and discussions among the involved parties.

Guidelines for the segregation characterization management of dry waste at Berkeley Lab

International Nuclear Information System (INIS)

1997-05-01

Managing and disposing of dry low level radioactive waste at Berkeley Lab. is problematic. The Waste Management Group must assure off site treatment, storage, and disposal facilities that dry waste from Berkeley Lab. is free of liquids and regulated metals (such as lead and mercury). RTR (Real Time Radioagraphy) used for waste to be rejected. This pamphlet helps to clarify dry waste management requirements that will ensure that Berkeley Lab. dry waste will be accepted for off site shipment. These issues are critical if we are to have an off site disposal option for your dry radioactive waste

BERKELEY: Light Source anniversary

International Nuclear Information System (INIS)

Anon.

1994-01-01

The staff of the Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory has been too busy to celebrate the first anniversary of the facility's transition from a US Department of Energy construction project to operating third-generation synchrotron radiation source. Based on a 1.5-GeV, low-emittance electron storage ring that accommodates up to ten insertion-device radiation sources optimized primarily for the soft X-ray and vacuum ultra-violet regions of the spectrum, the ALS has completed

BERKELEY: Light Source anniversary

Energy Technology Data Exchange (ETDEWEB)

Anon.

1994-10-15

The staff of the Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory has been too busy to celebrate the first anniversary of the facility's transition from a US Department of Energy construction project to operating third-generation synchrotron radiation source. Based on a 1.5-GeV, low-emittance electron storage ring that accommodates up to ten insertion-device radiation sources optimized primarily for the soft X-ray and vacuum ultra-violet regions of the spectrum, the ALS has completed.

UC Berkeley's Celebration of the International Year of Astronomy 2009

Science.gov (United States)

Cobb, B. E.; Croft, S.; Silverman, J. M.; Klein, C.; Modjaz, M.

2010-08-01

We present the astronomy outreach efforts undertaken for the International Year of Astronomy 2009 at the University of California, Berkeley. Our department-wide endeavors included a monthly public lecture series by UC Berkeley astronomers and a major astronomy outreach event during a campus-wide university "open house," which included solar observing and a Starlab Planetarium. In addition to sharing our outreach techniques and outcomes, we discuss some of our unique strategies for advertising our events to the local community.

Ernest Orlando Lawrence Berkeley National Laboratory Institutional Plan FY 2000-2004

Energy Technology Data Exchange (ETDEWEB)

Chartock, Mike (ed.); Hansen, Todd (ed.)

1999-08-01

The FY 2000-2004 Institutional Plan provides an overview of the Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab, the Laboratory) mission, strategic plan, initiatives, and the resources required to fulfill its role in support of national needs in fundamental science and technology, energy resources, and environmental quality. To advance the Department of Energy's ongoing efforts to define the Integrated Laboratory System, the Berkeley Lab Institutional Plan reflects the strategic elements of our planning efforts. The Institutional Plan is a management report that supports the Department of Energy's mission and programs and is an element of the Department of Energy's strategic management planning activities, developed through an annual planning process. The Plan supports the Government Performance and Results Act of 1993 and complements the performance-based contract between the Department of Energy and the Regents of the University of California. It identifies technical and administrative directions in the context of the national energy policy and research needs and the Department of Energy's program planning initiatives. Preparation of the plan is coordinated by the Office of Planning and Communications from information contributed by Berkeley Lab's scientific and support divisions.

Nuclear Medicine at Berkeley Lab: From Pioneering Beginnings to Today (LBNL Summer Lecture Series)

International Nuclear Information System (INIS)

Budinger, Thomas

2006-01-01

Summer Lecture Series 2006: Thomas Budinger, head of Berkeley Lab's Center for Functional Imaging, discusses Berkeley Lab's rich history pioneering the field of nuclear medicine, from radioisotopes to medical imaging.

BERKELEY: Collaboration on PEP-II

International Nuclear Information System (INIS)

Anon.

1995-01-01

Since the announcement by President Clinton in October 1993 that the US Department of Energy would going ahead the PEPII Asymmetric B Factory project (a joint proposal of the Stanford Linear Accelerator Center - SLAC, the Lawrence Berkeley National Laboratory - LBNL, and the Lawrence Livermore National Laboratory - LLNL), LBNL has continued its strong support of the project (for a review, see October, page 9). LBNL accelerator physicists have been active in the design of PEP-II since 1988 - shortly after the original concept was suggested by LBNL Deputy Director Pier Oddone. Indeed, the original feasibility study for such a machine was a joint LBNLSLAC- Caltech effort led by Swapan Chattopadhyay, now head of LBNL's Center for Beam Physics (CBP) in the Accelerator & Fusion Research Division (AFRD). The effort grew to include about seven full-time LBNL accelerator physicists (along with about 15 SLAC and LLNL physicists) during the formal design phase, which began in late 1989. This effort encompassed three editions of the Conceptual Design Report, along with innumerable reviews, as is typical of today's accelerator projects. Taking advantage of an experienced engineering staff, fresh from the successful completion of the Advanced Light Source (ALS), LBNL has been assigned lead responsibility for the challenging Low Energy Ring (LER) of the PEP-II project, an entirely new storage ring to be added to the PEP tunnel. The LBNL design team is headed by CBP accelerator physicist Michael Zisman and senior engineers Ron Yourd (who served as the Project Manager for the ALS) and Hank Hsieh (a recent addition to the LBNL staff who was Project Engineer for the NSLS storage rings at BNL and most recently served as Project Engineer for the DAFNE project at Frascati). LBNL is also represented in the overall management of the PEP-II project by Tom Elioff, who serves as Deputy to the Project Director Jonathan Dorfan at SLAC. (Elioff served in the same role for the original

IMPLEMENTASI SANDI HILL UNTUK PENYANDIAN CITRA

Directory of Open Access Journals (Sweden)

JJ Siang

2002-01-01

Full Text Available Hill's code is one of text encoding technique. In this research, Hill's code is extended to image encoding. The image used is BMP 24 bit format. 2x2 and 3x3 matrices is used as a key. The results show that Hill's code is suitable for image whose RGB values vary highly. On the contrary, it is not suitable for less varied RGB images since its original pattern is still persisted in encrypted image. Hill's code for image encoding has also disadvantage in the case that the key matrix is not unique. However, for daily application, with good key matrix, Hill's code can be applied to encode image since it's process only deals with simple matrix operation so it become fast. Abstract in Bahasa Indonesia : Sandi Hill merupakan salah satu teknik penyandian teks. Dalam penelitian ini, pemakaian sandi Hill diperluas dari teks ke citra bertipe BMP 24 bit. Matriks yang dipakai berordo 2x2 dan 3x3. Hasil percobaan menunjukkan bahwa sandi Hill cocok untuk enkripsi citra dengan variasi nilai RGB antar piksel berdekatan yang tinggi (seperti foto, tapi tidak cocok untuk citra dengan variasi nilai RGB yang rendah (seperti gambar kartun karena pola citra asli masih tampak dalam citra sandi. Sandi Hill juga memiliki kelemahan dalam hal tidak tunggalnya matriks kunci yang dapat dipakai. Akan tetapi untuk pemakaian biasa, dengan pemilihan matriks kunci yang baik, sandi Hill dapat dipakai untuk penyandian karena hanya melibatkan operasi matriks biasa sehingga prosesnya relatif cepat. Kata kunci: Sandi Hill, Citra, Relatif Prima.

Electron Microscope Center Opens at Berkeley.

Science.gov (United States)

Robinson, Arthur L.

1981-01-01

A 1.5-MeV High Voltage Electron Microscope has been installed at the Lawrence Berkeley Laboratory which will help materials scientists and biologists study samples in more true-to-life situations. A 1-MeV Atomic Resolution Microscope will be installed at the same location in two years which will allow scientists to distinguish atoms. (DS)

Superbends expand the scope of Berkeley's ALS

CERN Document Server

Robin, D S; Tamura, L S

2002-01-01

The first-ever retrofit of superconducting bend magnets into the storage ring of an operating synchrotron radiation source extends the spectrum of Lawrence Berkeley National Laboratory's Advanced Light Source into the hard-X-ray region without compromising soft X-ray availability, or performance. (4 refs).

Hill's formula

Energy Technology Data Exchange (ETDEWEB)

Bolotin, Sergey V [Steklov Mathematical Institute, Russian Academy of Sciences, Moscow (Russian Federation); Treschev, Dmitrii V [M. V. Lomonosov Moscow State University, Moscow (Russian Federation)

2010-07-27

In his study of periodic orbits of the three-body problem, Hill obtained a formula connecting the characteristic polynomial of the monodromy matrix of a periodic orbit with the infinite determinant of the Hessian of the action functional. A mathematically rigorous definition of the Hill determinant and a proof of Hill's formula were obtained later by Poincare. Here two multidimensional generalizations of Hill's formula are given: for discrete Lagrangian systems (symplectic twist maps) and for continuous Lagrangian systems. Additional aspects appearing in the presence of symmetries or reversibility are discussed. Also studied is the change of the Morse index of a periodic trajectory upon reduction of order in a system with symmetries. Applications are given to the problem of stability of periodic orbits. Bibliography: 34 titles.

The Origin of the Columbia Hills

Science.gov (United States)

Rice, J. W.

2005-12-01

The Columbia Hills form a rugged ridge complex comprised of 7 peaks spanning some 3.5 km in length and reaching a maximum height of 106 m (Husband Hill) above the plains of Spirit's landing site. As of this writing Spirit has been exploring the Columbia Hills for over 440 sols (since sol 156 on June 11, 2004). Thus far the origin of the Columbia Hills has remained elusive despite detailed analysis of numerous rock and soil targets, including outcrops. The chemical differences among the 6 distinct rock classes attest to the lithologic diversity and geologic complexity of the Hills. Origin of the Columbia Hills Several hypothesis have been put forth to explain the origin of the Columbia Hills: Old eroded partially buried impact crater rim(s), central peak, residual intracrater fill material, volcanic construct, wrinkle ridge, delta and or combinations of the above. Observations that support various aspects of these multiple hypotheses will be discussed. Numerous buried craters are observed on the floor of Gusev lending credence to the idea that the Columbia Hills are the remains of an ancient impact crater rim or possibly a central peak. Morphologic evidence of the rim of Thira crater and the Columbia Hills appears to support this hypothesis. The Aeolis region contains numerous craters that contain layered materials in the absence of any major fluvial systems. This could imply that the Columbia Hills are the remnants of a formerly extensive unit(s). Gusev contains many hills scattered across its floor such as Grissom, White, Chaffee and numerous other buttes and mesas that may be remnants of a former extensive intracrater deposit. Another possibility is that the Columbia Hills are composed of volcanic materials (cinder cones and associated ash and lava flows) derived either locally or from Apollinaris Patera located 300 km to the north. Several depressions are located in the Columbia Hills. These features could be calderas but are most likely impact craters. The most

The Hill Chart Calculation for Pelton Runner Models using the HydroHillChart - Pelton Module Software

Directory of Open Access Journals (Sweden)

Adelina Bostan

2015-07-01

Full Text Available The Pelton turbines industrial design is based on the hill chart characteristics obtained by measuring the models. Primary data measurements used to obtain the hill chart can be processed graphically, by hand or by using graphic programs respectively CAD programs; the HydroHillChart - Pelton module software is a specialized tool in achieving the hill chart, using interpolation cubic spline functions. Thereby, based on measurements of several models of Pelton turbines, a computerized library, used to design industrial Pelton turbines can be created. The paper presents the universal characteristics calculated by using the HydroHillChart - Pelton module software for a series of Pelton runners.

Disintegration of the Aged Open Cluster Berkeley 17

Energy Technology Data Exchange (ETDEWEB)

Bhattacharya, Souradeep; Vaidya, Kaushar [Department of Physics, Birla Institute of Technology and Science, Pilani 333031, Rajasthan (India); Mishra, Ishan [Indian Institute of Technology Guwahati, Guwahati 781039, Assam (India); Chen, W. P., E-mail: f2012553@pilani.bits-pilani.ac.in [Graduate Institute of Astronomy, National Central University, 300 Jhongda Road, Jhongli 32001, Taiwan (China)

2017-10-01

We present the analysis of the morphological shape of Berkeley 17, the oldest known open cluster (∼10 Gyr), using the probabilistic star counting of Pan-STARRS point sources, and confirm its core-tail shape, plus an antitail, previously detected with the 2MASS data. The stellar population, as diagnosed by the color–magnitude diagram and theoretical isochrones, shows many massive members in the clusters core, whereas there is a paucity of such members in both of the tails. This manifests mass segregation in this aged star cluster with the low-mass members being stripped away from the system. It has been claimed that Berkeley 17 is associated with an excessive number of blue straggler candidates. A comparison of nearby reference fields indicates that about half of these may be field contamination.

Berkeley Lab's ALS generates femtosecond synchrotron radiation

CERN Document Server

Robinson, A L

2000-01-01

A team at Berkeley's Advanced Light Source has shown how a laser time-slicing technique provides a path to experiments with ultrafast time resolution. A Lawrence Berkeley National Laboratory team has succeeded in generating 300 fs pulses of synchrotron radiation at the ALS synchrotron radiation machine. The team's members come from the Materials Sciences Division (MSD), the Center for Beam Physics in the Accelerator and Fusion Research Division and the Advanced Light Source (ALS). Although this proof-of principle experiment made use of visible light on a borrowed beamline, the laser "time-slicing" technique at the heart of the demonstration will soon be applied in a new bend magnet beamline that was designed specially for the production of femtosecond pulses of X-rays to study long-range and local order in condensed matter with ultrafast time resolution. An undulator beamline based on the same technique has been proposed that will dramatically increase the flux and brightness. The use of X-rays to study the c...

Loess Hills of Iowa

Data.gov (United States)

Iowa State University GIS Support and Research Facility — This coverage outlines the boundary of the Loess Hills in Iowa at 1:100,000 scale. Criteria applied to the delineation of the Loess Hills included drainage density,...

Flight style optimization in ski jumping on normal, large, and ski flying hills.

Science.gov (United States)

Jung, Alexander; Staat, Manfred; Müller, Wolfram

2014-02-07

In V-style ski jumping, aerodynamic forces are predominant performance factors and athletes have to solve difficult optimization problems in parts of a second in order to obtain their jump length maximum and to keep the flight stable. Here, a comprehensive set of wind tunnel data was used for optimization studies based on Pontryagin's minimum principle with both the angle of attack α and the body-ski angle β as controls. Various combinations of the constraints αmax and βmin(t) were analyzed in order to compare different optimization strategies. For the computer simulation studies, the Olympic hill profiles in Esto-Sadok, Russia (HS 106m, HS 140m), and in Harrachov, Czech Republic, host of the Ski Flying World Championships 2014 (HS 205m) were used. It is of high importance for ski jumping practice that various aerodynamic strategies, i.e. combinations of α- and β-time courses, can lead to similar jump lengths which enables athletes to win competitions using individual aerodynamic strategies. Optimization results also show that aerodynamic behavior has to be different at different hill sizes (HS). Optimized time courses of α and β using reduced drag and lift areas in order to mimic recent equipment regulations differed only in a negligible way. This indicates that optimization results presented here are not very sensitive to minor changes of the aerodynamic equipment features when similar jump length are obtained by using adequately higher in-run velocities. However, wind tunnel measurements with athletes including take-off and transition to stabilized flight, flight, and landing behavior would enable a more detailed understanding of individual flight style optimization. © 2013 Published by Elsevier Ltd.

Hybrid Wing Body Model Identification Using Forced-Oscillation Water Tunnel Data

Science.gov (United States)

Murphy, Patrick C.; Vicroy, Dan D.; Kramer, Brian; Kerho, Michael

2014-01-01

Static and dynamic testing of the NASA 0.7 percent scale Hybrid Wing Body (HWB) configuration was conducted in the Rolling Hills Research Corporation water tunnel to investigate aerodynamic behavior over a large range of angle-of-attack and to develop models that can predict aircraft response in nonlinear unsteady flight regimes. This paper reports primarily on the longitudinal axis results. Flow visualization tests were also performed. These tests provide additional static data and new dynamic data that complement tests conducted at NASA Langley 14- by 22-Foot Subsonic Tunnel. HWB was developed to support the NASA Environmentally Responsible Aviation Project goals of lower noise, emissions, and fuel burn. This study also supports the NASA Aviation Safety Program efforts to model and control advanced transport configurations in loss-of-control conditions.

Multiple Landslide-Hazard Scenarios Modeled for the Oakland-Berkeley Area, Northern California

Science.gov (United States)

Pike, Richard J.; Graymer, Russell W.

2008-01-01

With the exception of Los Angeles, perhaps no urban area in the United States is more at risk from landsliding, triggered by either precipitation or earthquake, than the San Francisco Bay region of northern California. By January each year, seasonal winter storms usually bring moisture levels of San Francisco Bay region hillsides to the point of saturation, after which additional heavy rainfall may induce landslides of various types and levels of severity. In addition, movement at any time along one of several active faults in the area may generate an earthquake large enough to trigger landslides. The danger to life and property rises each year as local populations continue to expand and more hillsides are graded for development of residential housing and its supporting infrastructure. The chapters in the text consist of: *Introduction by Russell W. Graymer *Chapter 1 Rainfall Thresholds for Landslide Activity, San Francisco Bay Region, Northern California by Raymond C. Wilson *Chapter 2 Susceptibility to Deep-Seated Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike and Steven Sobieszczyk *Chapter 3 Susceptibility to Shallow Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Kevin M. Schmidt and Steven Sobieszczyk *Chapter 4 Landslide Hazard Modeled for the Cities of Oakland, Piedmont, and Berkeley, Northern California, from a M=7.1 Scenario Earthquake on the Hayward Fault Zone by Scott B. Miles and David K. Keefer *Chapter 5 Synthesis of Landslide-Hazard Scenarios Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike The plates consist of: *Plate 1 Susceptibility to Deep-Seated Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike, Russell W. Graymer, Sebastian Roberts, Naomi B. Kalman, and Steven Sobieszczyk *Plate 2 Susceptibility to Shallow Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Kevin M. Schmidt and Steven

Antigravity hills are visual illusions.

Science.gov (United States)

Bressan, Paola; Garlaschelli, Luigi; Barracano, Monica

2003-09-01

Antigravity hills, also known as spook hills or magnetic hills, are natural places where cars put into neutral are seen to move uphill on a slightly sloping road, apparently defying the law of gravity. We show that these effects, popularly attributed to gravitational anomalies, are in fact visual illusions. We re-created all the known types of antigravity spots in our laboratory using tabletop models; the number of visible stretches of road, their slant, and the height of the visible horizon were systematically varied in four experiments. We conclude that antigravity-hill effects follow from a misperception of the eye level relative to gravity, caused by the presence of either contextual inclines or a false horizon line.

New Cepheid variables in the young open clusters Berkeley 51 and Berkeley 55

Science.gov (United States)

Lohr, M. E.; Negueruela, I.; Tabernero, H. M.; Clark, J. S.; Lewis, F.; Roche, P.

2018-05-01

As part of a wider investigation of evolved massive stars in Galactic open clusters, we have spectroscopically identified three candidate classical Cepheids in the little-studied clusters Berkeley 51, Berkeley 55 and NGC 6603. Using new multi-epoch photometry, we confirm that Be 51 #162 and Be 55 #107 are bona fide Cepheids, with pulsation periods of 9.83±0.01 d and 5.850±0.005 d respectively, while NGC 6603 star W2249 does not show significant photometric variability. Using the period-luminosity relationship for Cepheid variables, we determine a distance to Be 51 of 5.3^{+1.0}_{-0.8} kpc and an age of 44^{+9}_{-8} Myr, placing it in a sparsely-attested region of the Perseus arm. For Be 55, we find a distance of 2.2±0.3 kpc and age of 63^{+12}_{-11} Myr, locating the cluster in the Local arm. Taken together with our recent discovery of a long-period Cepheid in the starburst cluster VdBH222, these represent an important increase in the number of young, massive Cepheids known in Galactic open clusters. We also consider new Gaia (data release 2) parallaxes and proper motions for members of Be 51 and Be 55; the uncertainties on the parallaxes do not allow us to refine our distance estimates to these clusters, but the well-constrained proper motion measurements furnish further confirmation of cluster membership. However, future final Gaia parallaxes for such objects should provide valuable independent distance measurements, improving the calibration of the period-luminosity relationship, with implications for the distance ladder out to cosmological scales.

Berkeley Experiments on Superfluid Macroscopic Quantum Effects

International Nuclear Information System (INIS)

Packard, Richard

2006-01-01

This paper provides a brief history of the evolution of the Berkeley experiments on macroscopic quantum effects in superfluid helium. The narrative follows the evolution of the experiments proceeding from the detection of single vortex lines to vortex photography to quantized circulation in 3He to Josephson effects and superfluid gyroscopes in both 4He and 3He

Berkeley Lab Sheds Light on Improving Solar Cell Efficiency

International Nuclear Information System (INIS)

Lawrence Berkeley National Laboratory

2007-01-01

Typical manufacturing methods produce solar cells with an efficiency of 12-15%; and 14% efficiency is the bare minimum for achieving a profit. In work performed at the Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley, CA, 5 10-486-577 1)--a US Department of Energy national laboratory that conducts unclassified scientific research and is managed by the University of California--scientist Scott McHugo has obtained keen insights into the impaired performance of solar cells manufactured from polycrystalline silicon. The solar cell market is potentially vast, according to Berkeley Lab. Lightweight solar panels are highly beneficial for providing electrical power to remote locations in developing nations, since there is no need to build transmission lines or truck-in generator fuel. Moreover, industrial nations confronted with diminishing resources have active programs aimed at producing improved, less expensive solar cells. 'In a solar cell, there is a junction between p-type silicon and an n-type layer, such as diffused-in phosphorous', explained McHugo, who is now with Berkeley Lab's Accelerator and Fusion Research Division. 'When sunlight is absorbed, it frees electrons, which start migrating in a random-walk fashion toward that junction. If the electrons make it to the junction; they contribute to the cell's output of electric current. Often, however, before they reach the junction, they recombine at specific sites in the crystal' (and, therefore, cannot contribute to current output). McHugo scrutinized a map of a silicon wafer in which sites of high recombination appeared as dark regions. Previously, researchers had shown that such phenomena occurred not primarily at grain boundaries in the polycrystalline material, as might be expected, but more often at dislocations in the crystal. However, the dislocations themselves were not the problem. Using a unique heat treatment technique, McHugo performed electrical measurements to investigate the material

Berkeley automated supernova search

Energy Technology Data Exchange (ETDEWEB)

Kare, J.T.; Pennypacker, C.R.; Muller, R.A.; Mast, T.S.; Crawford, F.S.; Burns, M.S.

1981-01-01

The Berkeley automated supernova search employs a computer controlled 36-inch telescope and charge coupled device (CCD) detector to image 2500 galaxies per night. A dedicated minicomputer compares each galaxy image with stored reference data to identify supernovae in real time. The threshold for detection is m/sub v/ = 18.8. We plan to monitor roughly 500 galaxies in Virgo and closer every night, and an additional 6000 galaxies out to 70 Mpc on a three night cycle. This should yield very early detection of several supernovae per year for detailed study, and reliable premaximum detection of roughly 100 supernovae per year for statistical studies. The search should be operational in mid-1982.

Berkeley automated supernova search

International Nuclear Information System (INIS)

Kare, J.T.; Pennypacker, C.R.; Muller, R.A.; Mast, T.S.

1981-01-01

The Berkeley automated supernova search employs a computer controlled 36-inch telescope and charge coupled device (CCD) detector to image 2500 galaxies per night. A dedicated minicomputer compares each galaxy image with stored reference data to identify supernovae in real time. The threshold for detection is m/sub v/ = 18.8. We plan to monitor roughly 500 galaxies in Virgo and closer every night, and an additional 6000 galaxies out to 70 Mpc on a three night cycle. This should yield very early detection of several supernovae per year for detailed study, and reliable premaximum detection of roughly 100 supernovae per year for statistical studies. The search should be operational in mid-1982

Lawrence Berkeley Laboratory Institutional Plan FY 1995--2000

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-12-01

This report presents the details of the mission and strategic plan for Lawrence Berkeley Laboratory during the fiscal years of 1995--2000. It presents summaries of current programs and potential changes; critical success factors such as human resources; management practices; budgetary allowances; and technical and administrative initiatives.

Berkeley extreme-ultraviolet airglow rocket spectrometer - BEARS

Science.gov (United States)

Cotton, D. M.; Chakrabarti, S.

1992-01-01

The Berkeley EUV airglow rocket spectrometer (BEARS) instrument is described. The instrument was designed in particular to measure the dominant lines of atomic oxygen in the FUV and EUV dayglow at 1356, 1304, 1027, and 989 A, which is the ultimate source of airglow emissions. The optical and mechanical design of the instrument, the detector, electronics, calibration, flight operations, and results are examined.

Berkeley Lab Pilot on External Regulation of DOE National Laboratories by the U.S. NRC

International Nuclear Information System (INIS)

Zeman, Gary H.

1999-01-01

The US Department of Energy and the US Nuclear Regulatory Commission entered into an agreement in November 1997 to pursue external regulation of radiation safety at DOE national laboratories through a Pilot Program of simulated regulation at 6-10 sites over a 2 year period. The Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab), the oldest of the DOE national laboratories, volunteered and was selected as the first Pilot site. Based on the similarities and linkages between Berkeley Lab and nearby university research laboratories, Berkeley Lab seemed a good candidate for external regulation and a good first step in familiarizing NRC with the technical and institutional issues involved in regulating laboratories in the DOE complex. NRC and DOE team members visited Berkeley Lab on four occasions between October 1997 and January 1998 to carry out the Pilot. The first step was to develop a detailed Work Plan, then to carry out both a technical review of the radiation safety program and an examination of policy and regulatory issues. The Pilot included a public meeting held in Oakland, CA in December 1997. The Pilot concluded with NRC's assessment that Berkeley Lab has a radiation protection program adequate to protect workers, the public and the environment, and that it is ready to be licensed by the NRC with minor programmatic exceptions. A draft final report of the Pilot was prepared and circulated for comment as a NUREG document (dated May 7, 1998). The report's recommendations include extending NRC regulatory authority to cover all ionizing radiation sources (including accelerators, x-ray units, NARM) at Berkeley Lab. Questions remaining to be resolved include: who should be the licensee (DOE, the Lab, or both)?; dealing with legacy issues and NRC D and D requirements; minimizing dual oversight; quantifying value added in terms of cost savings, enhanced safety, and improved public perception; extrapolating results to other national laboratories; and

Observations of Local ISM Emission with the Berkeley EUV/FUV Shuttle Telescope

Science.gov (United States)

Martin, C.; Bowyer, S.

1984-01-01

The Berkeley extreme ultraviolet/far ultraviolet shuttle telescope (BEST) will be launched on the Space Shuttle as part of the NASA UVX project. The Berkeley spectrometer will make observations of the cosmic diffuse background in the 600 to 1900 A band, with a spectral resolution of 10 A. The sensitivity and spectral resolution of the instrument make it ideal for the study of components of the interstellar medium in the 10 to the 4th power to 10 to the 6th power K range.

Lawrence Berkeley National Laboratory 2016 Annual Financial Report

Energy Technology Data Exchange (ETDEWEB)

Williams, Kim, P.; Williams, Kim, P.

2017-06-27

FY2016 was a year of significant change and progress at Berkeley Lab. In March, Laboratory Director Michael Witherell assumed his new role when former Lab Director Paul Alivisatos became Vice Chancellor for Research at UC Berkeley. Dr. Witherell has solidified the Lab’s strategy, with a focus on long term science and technology priorities. Large-scale science efforts continued to expand at the Lab, including the Dark Energy Spectroscopic Instrument now heading towards construction, and the LUX-ZEPLIN dark matter detector to be built underground in South Dakota. Another proposed project, the Advanced Light Source-Upgrade, was given preliminary approval and will be the Lab’s largest scientific investment in years. Construction of the Integrative Genomics Building began, and will bring together researchers from the Lab’s Joint Genome Institute, now based in Walnut Creek, and the Systems Biology Knowledgebase (K-Base) under one roof. Investment in the Lab’s infrastructure also continues, informed by the Lab’s Infrastructure Strategic Plan. Another important focus is on developing the next generation of scientists with the talent and diversity needed to sustain Berkeley Lab’s scientific leadership and mission contributions to DOE and the Nation. Berkeley Lab received $897.5M in new FY2016 funding, a 12.5% increase over FY2015, for both programmatic and infrastructure activities. While the Laboratory experienced a substantial increase in funding, it was accompanied by only a modest increase in spending, as areas of growth were partially offset by the completion of several major efforts in FY2015. FY2016 costs were $826.9M, an increase of 1.9% over FY2015. Similar to the prior year, the indirect-funded Operations units worked with generally flat budgets to yield more funding for strategic needs. A key challenge for Berkeley Lab continues to be achieving the best balance to fund essential investments, deliver highly effective operational mission support and

Annual environmental monitoring report of the Lawrence Berkeley Laboratory, 1980

International Nuclear Information System (INIS)

Schleimer, G.E.

1981-04-01

The Environmental Monitoring Program of the Lawrence Berkeley Laboratory is described. Data on air and water sampling and continuous radiation monitoring for 1980 are presented, and general trends are discussed

Berkeley Lab Computing Sciences: Accelerating Scientific Discovery

International Nuclear Information System (INIS)

Hules, John A.

2008-01-01

Scientists today rely on advances in computer science, mathematics, and computational science, as well as large-scale computing and networking facilities, to increase our understanding of ourselves, our planet, and our universe. Berkeley Lab's Computing Sciences organization researches, develops, and deploys new tools and technologies to meet these needs and to advance research in such areas as global climate change, combustion, fusion energy, nanotechnology, biology, and astrophysics

Tunnel magnetoresistance in alumina, magnesia and composite tunnel barrier magnetic tunnel junctions

International Nuclear Information System (INIS)

Schebaum, Oliver; Drewello, Volker; Auge, Alexander; Reiss, Guenter; Muenzenberg, Markus; Schuhmann, Henning; Seibt, Michael; Thomas, Andy

2011-01-01

Using magnetron sputtering, we have prepared Co-Fe-B/tunnel barrier/Co-Fe-B magnetic tunnel junctions with tunnel barriers consisting of alumina, magnesia, and magnesia-alumina bilayer systems. The highest tunnel magnetoresistance ratios we found were 73% for alumina and 323% for magnesia-based tunnel junctions. Additionally, tunnel junctions with a unified layer stack were prepared for the three different barriers. In these systems, the tunnel magnetoresistance ratios at optimum annealing temperatures were found to be 65% for alumina, 173% for magnesia, and 78% for the composite tunnel barriers. The similar tunnel magnetoresistance ratios of the tunnel junctions containing alumina provide evidence that coherent tunneling is suppressed by the alumina layer in the composite tunnel barrier. - Research highlights: → Transport properties of Co-Fe-B/tunnel barrier/Co-Fe-B magnetic tunnel junctions. → Tunnel barrier consists of MgO, Al-Ox, or MgO/Al-Ox bilayer systems. → Limitation of TMR-ratio in composite barrier tunnel junctions to Al-Ox values. → Limitation indicates that Al-Ox layer is causing incoherent tunneling.

Long-life cathode for the Berkeley-type ion source

International Nuclear Information System (INIS)

Fink, J.H.; Biagi, L.A.

1977-01-01

Preliminary experiments indicate that a hollow cathode, made from impregnated tungsten emitters, can be adapted for the Lawrence Berkeley Laboratory (LBL)/Lawrence Livermore Laboratory (LLL) ion source. Such cathodes could be the basis of a long life, continuously operated positive-ion source

Lawrence Berkeley Laboratory 1993 Site Environmental Report

Energy Technology Data Exchange (ETDEWEB)

1994-05-01

This annual Site Environmental Report summarizes Lawrence Berkeley Laboratory`s (LBL`s) environmental activities in calendar year (CY) 1993. The purpose of this report is to characterize site environmental management performance, confirm compliance status with environmental standards and requirements, and highlight significant programs and efforts. Its format and content are consistent with the requirements of the US Department of Energy (DOE) Order 5400.1, General Environmental Protection Program.

The decommissioning of Berkeley II

International Nuclear Information System (INIS)

Hannan, A.

2002-01-01

This paper describes the decommissioning progress at the Magnox site at Berkeley in Gloucestershire.Throughout the work at Berkeley the emphasis has been on conducting decommissioning safely. This has been reflected in the progress of decommissioning starting with removal of the fuel from site and thus much greater than 99% of the radioactive inventory. The major radioactive hazard is the Intermediate Level Waste in the form of fuel element debris (graphite struts and extraneous magnox components removed to increase the packing density of fuel elements in flasks going to Sellafield), miscellaneous activated components, sludges and resins. Approximately 1500 m 3 of such material exists and is stored in underground waste vaults on site. Work is underway to recover and encapsulate the waste in cement so rendering it 'passively safe'. All work on site is covered by a nuclear safety case which has a key objective of minimising the radiological exposures that could accrue to workers. Reflecting this an early decision has been taken to leave work on the Reactor Pressure Vessels themselves for several decades. Also important in protection of the workforce has been control of asbestos.Much material has been removed with redundant plant and equipment, but a programme of remediation in line with government legislation has been required to ensure personnel safety throughout the decommissioning period and into Care and Maintenance.In addition to health and safety matters the site approach to environmental issues has been consistent. Formally such standards as ISO 14001 have been adhered to and the appropriate certification maintained. At a working level the principles of reduce, reuse and recycle have been inculcated

UC-Berkeley-area citizens decry waste transfer from lab.

CERN Multimedia

Nakasato, L

2002-01-01

Residents are working to stop the transfer of potentially hazardous and radioactive material from Lawrence Berkeley National Laboratory. The lab has begun to dismantle the Bevatron which has been shut down since 1993 and says eight trucks per day will move material offsite (1 page).

Magnetic Quantum Tunneling in Single Molecule Magnets: Mn-12 and Others

Science.gov (United States)

del Barco, Enrique

2004-03-01

Magnetic quantum tunneling (MQT) has been studied in single molecule magnets (SMMs) using a micro-Hall effect magnetometer in a superconducting high field vector magnet system that incorporates the possibility of applying pulsed microwave fields. Mn_12-acetate has been studied extensively over the years. However, only recently the symmetry of MQT and the nature of the transverse interactions important to MQT have been determined [1,2]. Magnetic measurements in the pure quantum tunneling regime (0.6 K) illustrate that an average crystal fourfold MQT symmetry is due to local molecular environments of twofold symmetry that are rotated by 90 degrees with respect to one another, confirming that disorder which lowers the molecule symmetry is important to MQT. We have studied a subset of these lower site symmetry molecules and present evidence for a Berry phase that results from a combination of second and forth order contributions to the transverse magnetic anisotropy. These observations are consistent with high frequency EPR studies of the transverse interactions in Mn_12-acetate [3]. Finally, we discuss recent experiments in which microwave radiation is applied to modulate MQT and characterize the lifetimes and coherence times of states that are superpositions of "up" and "down" high spin-projections. [1] E. del Barco, et al., Phys. Rev. Lett. 91, 047203 (2003) [2] S. Hill, et al., Phys. Rev. Lett. 90, 217204 (2003). [3] E. del Barco, A, D. Kent, R. S. Edwards, S. I. Jones, S. Hill, J. M. North, N. S. Dalal, E. M. Rumnberger, D. N. Hendrickson and G. Christou, to be published.

The Indirect Perception of Distance: Interpretive Complexities in Berkeley's Theory of Vision

Directory of Open Access Journals (Sweden)

Michael James Braund

2007-12-01

Full Text Available The problem of whether perception is direct or if it depends on additional, cognitive contributions made by the perceiving subject, is posed with particular force in an Essay towards a New Theory of Vision (NTV. It is evident from the recurrent treatment it receives therein that Berkeley considers it to be one of the central issues concerning perception. Fittingly, the NTV devotes the most attention to it. In this essay, I deal exclusively with Berkeley's treatment of the problem of indirect distance perception, as it is presented in the context of that work.

Environmental Assessment for the proposed Induction Linac System Experiments in Building 51B at Lawrence Berkeley National Laboratory, Berkeley, California

International Nuclear Information System (INIS)

1995-08-01

The US Department of Energy (DOE) has prepared an Environmental Assessment (EA), (DOE/EA-1087) evaluating the proposed action to modify existing Building 51B at Lawrence Berkeley National Laboratory (LBNL) to install and conduct experiments on a new Induction Linear Accelerator System. LBNL is located in Berkeley, California and operated by the University of California (UC). The project consists of placing a pre-fabricated building inside Building 51B to house a new 10 MeV heavy ion linear accelerator. A control room and other support areas would be provided within and directly adjacent to Building 51B. The accelerator system would be used to conduct tests, at reduced scale and cost, many features of a heavy-ion accelerator driver for the Department of Energy's inertial fusion energy program. Based upon information and analyses in the EA, the DOE has determined that the proposed action is not a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act of 1969. Therefore, an Environmental Impact Statement is not required. This report contains the Environmental Assessment, as well as the Finding of No Significant Impact (FONSI)

New nuclear physics at Berkeley Conference

International Nuclear Information System (INIS)

Anon.

1980-01-01

One of the highlights of the summer was the International Conference on Nuclear Physics, held at Berkeley in August. These big meetings provide a periodic focus for the nuclear physics community. Overall, the Conference paid a lot of attention to topics and phenomna which only a few years ago would have been considered exotic. With many novel ideas being put forward and with new projects afoot, a lot of fresh ground could have been covered by the time of the next meeting, scheduled to be held in Florence in a few years

Environmental assessment for construction and operation of a Human Genome Laboratory at Lawrence Berkeley Laboratory, Berkeley, California

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-12-01

Lawrence Berkeley Laboratory (LBL) proposes to construct and operate a new laboratory for consolidation of current and future activities of the Human Genome Center (HGC). This document addresses the potential direct, indirect, and cumulative environmental and human-health effects from the proposed facility construction and operation. This document was prepared in accordance the National Environmental Policy Act of 1969 (United States Codes 42 USC 4321-4347) (NEPA) and the US Department of Energy`s (DOE) Final Rule for NEPA Implementing Procedures [Code of Federal Regulations 10CFR 1021].

The Beginner's Guide to Wind Tunnels with TunnelSim and TunnelSys

Science.gov (United States)

Benson, Thomas J.; Galica, Carol A.; Vila, Anthony J.

2010-01-01

The Beginner's Guide to Wind Tunnels is a Web-based, on-line textbook that explains and demonstrates the history, physics, and mathematics involved with wind tunnels and wind tunnel testing. The Web site contains several interactive computer programs to demonstrate scientific principles. TunnelSim is an interactive, educational computer program that demonstrates basic wind tunnel design and operation. TunnelSim is a Java (Sun Microsystems Inc.) applet that solves the continuity and Bernoulli equations to determine the velocity and pressure throughout a tunnel design. TunnelSys is a group of Java applications that mimic wind tunnel testing techniques. Using TunnelSys, a team of students designs, tests, and post-processes the data for a virtual, low speed, and aircraft wing.

Annual environmental monitoring report of the Lawrence Berkeley Laboratory, 1986

International Nuclear Information System (INIS)

Schleimer, G.E.

1987-04-01

The Environmental Monitoring Program of the Lawrence Berkeley Laboratory is described. Data for 1986 are presented and general trends are discussed. Topics include radiation monitoring, wastewater discharge monitoring, dose distribution estimates, and ground water monitoring. 9 refs., 8 figs., 20 tabs

HydroHillChart – Francis module. Software used to Calculate the Hill Chart of the Francis Hydraulic Turbines

Directory of Open Access Journals (Sweden)

Dorian Nedelcu

2015-07-01

Full Text Available The paper presents the Hydro Hill Chart - Francis module application, used to calculate the hill chart of the Pelton, Francis and Kaplan hydraulic turbine models, by processing the data measured on the stand. After describing the interface and menu, the input data is graphically presented and the universal characteristic for measuring scenarios ao=const. and n11=const is calculated. Finally, the two calculated hill charts are compared through a graphical superimposition of the isolines.

27 CFR 9.190 - Red Hill Douglas County, Oregon.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Red Hill Douglas County... Areas § 9.190 Red Hill Douglas County, Oregon. (a) Name. The name of the viticultural area described in this section is “Red Hill Douglas County, Oregon”. For purposes of part 4 of this chapter, “Red Hill...

Environmental health-risk assessment for tritium releases at the National Tritium Labeling Facility at Lawrence Berkeley National Laboratory

Energy Technology Data Exchange (ETDEWEB)

McKone, T.E.; Brand, K.P. [Lawrence Livermore National Lab., CA (United States). Health and Ecological Assessment Div.; Shan, C. [Lawrence Berkeley National Lab., CA (United States). Earth Sciences Div.

1997-04-01

This risk assessment calculates the probability of experiencing health effects, including cancer incidence due to tritium exposure for three groups of people: (1) LBNL workers near the LBNL facility--Building 75--that uses tritium; (2) other workers at LBNL and nearby neighbors; and (3) people who use the UC Berkeley campus area, and some Berkeley residents. All of these groups share the same probability of health effects from the background radiation from natural sources in the Berkeley area environment, including an increased risk of developing a cancer of 11,000 chances per million. In calculating risk the authors assumed continuous operation in Building 75 for at least a human lifetime. Under this assumption, LBNL workers located near Building 75 have an additional risk of 60 chances out of one million to suffer a cancer; other workers at LBNL and people who live near LBNL have an additional risk of six chances out of one million over a lifetime of exposure; and users of the UC Berkeley campus area and other residents of Berkeley have an additional risk of less than once chance out of one million over a lifetime.

Environmental health-risk assessment for tritium releases at the National Tritium Labeling Facility at Lawrence Berkeley National Laboratory

International Nuclear Information System (INIS)

McKone, T.E.; Brand, K.P.; Shan, C.

1997-04-01

This risk assessment calculates the probability of experiencing health effects, including cancer incidence due to tritium exposure for three groups of people: (1) LBNL workers near the LBNL facility--Building 75--that uses tritium; (2) other workers at LBNL and nearby neighbors; and (3) people who use the UC Berkeley campus area, and some Berkeley residents. All of these groups share the same probability of health effects from the background radiation from natural sources in the Berkeley area environment, including an increased risk of developing a cancer of 11,000 chances per million. In calculating risk the authors assumed continuous operation in Building 75 for at least a human lifetime. Under this assumption, LBNL workers located near Building 75 have an additional risk of 60 chances out of one million to suffer a cancer; other workers at LBNL and people who live near LBNL have an additional risk of six chances out of one million over a lifetime of exposure; and users of the UC Berkeley campus area and other residents of Berkeley have an additional risk of less than once chance out of one million over a lifetime

Seasonal variations of natural ventilation and radon-222 exhalation in a slightly rising dead-end tunnel.

Science.gov (United States)

Perrier, Frédéric; Richon, Patrick; Gautam, Umesh; Tiwari, Dilli Ram; Shrestha, Prithvi; Sapkota, Soma Nath

2007-01-01

The concentration activity of radon-222 has been monitored, with some interruptions, from 1997 to 2005 in the end section of a slightly rising, dead-end, 38-m long tunnel located in the Phulchoki hill, near Kathmandu, Nepal. While a high concentration varying from 6 x 10(3) Bq m(-3) to 10 x 10(3) Bq m(-3) is observed from May to September (rainy summer season), the concentration remains at a low level of about 200 Bq m(-3) from October to March (dry winter season). This reduction of radon concentration is associated with natural ventilation of the tunnel, which, contrary to expectations for a rising tunnel, takes place mainly from October to March when the outside air temperature drops below the average tunnel temperature. This interpretation is supported by temperature measurements in the atmosphere of the tunnel, a few meters away from the entrance. The temporal variations of the diurnal amplitude of this temperature indeed follow the ventilation rate deduced from the radon measurements. In the absence of significant ventilation (summer season), the radon exhalation flux at the rock surface into the tunnel atmosphere can be inferred; it exhibits a yearly variation with additional transient reductions associated with heavy rainfall, likely to be due to water infiltration. No effect of atmospheric pressure variations on the radon concentration is observed in this tunnel. This experiment illustrates how small differences in the location and geometry of a tunnel can lead to vastly different behaviours of the radon concentration versus time. This observation has consequences for the estimation of the dose rate and the practicability of radon monitoring for tectonic purposes in underground environments.

A Radiation Homeland Security Workshop Presented to the City of Berkeley Fire Department

Science.gov (United States)

Matis, Howard

2005-04-01

A radiation incident in a community, ranging from a transportation accident to a dirty bomb, is expected to be rare, but still can occur. First responders to such an incident must be prepared. City of Berkeley officials met with members of the Lawrence Berkeley National Laboratory staff and agreed that the laboratory participants would create material and teach it to all of their fire fighting staff. To design such a course, nuclear physicists, biologists and health physicists merged some of their existing teaching material together with previous homeland security efforts to produce a course that lasted one full day. The material was designed to help alleviate the myths and fear of radiation experienced by many first responders. It included basic nuclear physics information, biological effects, and methods that health physicists use to detect and handle radiation. The curriculum included several hands on activities which involved working directly with the meters the Berkeley Fire Department possessed. In addition, I will discuss some observations from teaching this course material plus some unusual problems that we encountered, such as suddenly the whole class responding to a fire.

Berkeley High-Resolution Ball

International Nuclear Information System (INIS)

Diamond, R.M.

1984-10-01

Criteria for a high-resolution γ-ray system are discussed. Desirable properties are high resolution, good response function, and moderate solid angle so as to achieve not only double- but triple-coincidences with good statistics. The Berkeley High-Resolution Ball involved the first use of bismuth germanate (BGO) for anti-Compton shield for Ge detectors. The resulting compact shield permitted rather close packing of 21 detectors around a target. In addition, a small central BGO ball gives the total γ-ray energy and multiplicity, as well as the angular pattern of the γ rays. The 21-detector array is nearly complete, and the central ball has been designed, but not yet constructed. First results taken with 9 detector modules are shown for the nucleus 156 Er. The complex decay scheme indicates a transition from collective rotation (prolate shape) to single- particle states (possibly oblate) near spin 30 h, and has other interesting features

A Community of Scientists and Educators: The Compass Project at UC Berkeley

Science.gov (United States)

Roth, Nathaniel; Schwab, Josiah

2016-01-01

The Berkeley Compass Project is a self-formed group of graduate and undergraduate students in the physical sciences at the University of California, Berkeley. Its goals are to improve undergraduate physics education, provide opportunities for professional development, and increase retention of students from populations underrepresented in the physical sciences. For undergraduate students, the core Compass experience consists of a summer program and several seminar courses. These programs are designed to foster a diverse, collaborative student community in which students engage in authentic research practices and regular self-reflection. Graduate students, together with upper-level undergraduates, design and run all Compass programs. Compass strives to incorporate best practices from the science education literature. Experiences in Compass leave participants poised to be successful students researchers, teachers, and mentors.

Lawrence Berkeley Laboratory 1994 site environmental report

International Nuclear Information System (INIS)

1995-05-01

The 1994 Site Environmental Report summarizes environmental activities at Lawrence Berkeley Laboratory (LBL) for the calendar year (CY) 1994. The report strives to present environmental data in a manner that characterizes the performance and compliance status of the Laboratory's environmental management programs when measured against regulatory standards and DOE requirements. The report also discusses significant highlight and planning efforts of these programs. The format and content of the report are consistent with the requirements of the U.S. Department of Energy (DOE) Order 5400.1, General Environmental Protection Program

Lawrence Berkeley Laboratory 1994 site environmental report

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-05-01

The 1994 Site Environmental Report summarizes environmental activities at Lawrence Berkeley Laboratory (LBL) for the calendar year (CY) 1994. The report strives to present environmental data in a manner that characterizes the performance and compliance status of the Laboratory`s environmental management programs when measured against regulatory standards and DOE requirements. The report also discusses significant highlight and planning efforts of these programs. The format and content of the report are consistent with the requirements of the U.S. Department of Energy (DOE) Order 5400.1, General Environmental Protection Program.

Tunneling technologies for the collider ring tunnels

International Nuclear Information System (INIS)

Frobenius, P.

1989-01-01

The Texas site chosen for the Superconducting Super Collider has been studied, and it has been determined that proven, conventional technology and accepted engineering practice are suitable for constructing the collider tunnels. The Texas National Research Laboratory Commission report recommended that two types of tunneling machines be used for construction of the tunnels: a conventional hard rock tunnel boring machine (TBM) for the Austin chalk and a double shielded, rotary TBM for the Taylor marl. Since the tunneling machines usually set the pace for the project, efficient planning, operation, and coordination of the tunneling system components will be critical to the schedule and cost of the project. During design, tunneling rate prediction should be refined by focusing on the development of an effective tunneling system and evaluating its capacity to meet or exceed the required schedules. 8 refs., 13 figs

Guide to user facilities at the Lawrence Berkeley Laboratory

International Nuclear Information System (INIS)

1984-04-01

Lawrence Berkeley Laboratories' user facilities are described. Specific facilities include: the National Center for Electron Microscopy; the Bevalac; the SuperHILAC; the Neutral Beam Engineering Test Facility; the National Tritium Labeling Facility; the 88 inch Cyclotron; the Heavy Charged-Particle Treatment Facility; the 2.5 MeV Van de Graaff; the Sky Simulator; the Center for Computational Seismology; and the Low Background Counting Facility

HydroHillChart – Pelton module. Software used to Calculate the Hill Chart of the Pelton Hydraulic Turbines

OpenAIRE

Dorian Nedelcu; Adelina Bostan; Florin Peris-Bendu

2015-01-01

The paper presents the HydroHillChart - Pelton module application, used to calculate the hill chart of the Pelton hydraulic turbine models, by processing the data measured on the stand. In addition, the tools offered by the application such as: interface, menu, input data, numerical and graphical results, etc. are described.

Confidence Hills Mineralogy and Chemin Results from Base of Mt. Sharp, Pahrump Hills, Gale Crater, Mars

Science.gov (United States)

Cavanagh, P. D.; Bish, D. L.; Blake, D. F.; Vaniman, D. T.; Morris, R. V.; Ming, D. W.; Rampe, E. B.; Achilles, C. N.; Chipera, S. J.; Treiman, A. H.;

The Bradford Hill considerations on causality: a counterfactual perspective

Directory of Open Access Journals (Sweden)

Höfler Michael

2005-11-01

Full Text Available Abstract Bradford Hill's considerations published in 1965 had an enormous influence on attempts to separate causal from non-causal explanations of observed associations. These considerations were often applied as a checklist of criteria, although they were by no means intended to be used in this way by Hill himself. Hill, however, avoided defining explicitly what he meant by "causal effect". This paper provides a fresh point of view on Hill's considerations from the perspective of counterfactual causality. I argue that counterfactual arguments strongly contribute to the question of when to apply the Hill considerations. Some of the considerations, however, involve many counterfactuals in a broader causal system, and their heuristic value decreases as the complexity of a system increases; the danger of misapplying them can be high. The impacts of these insights for study design and data analysis are discussed. The key analysis tool to assess the applicability of Hill's considerations is multiple bias modelling (Bayesian methods and Monte Carlo sensitivity analysis; these methods should be used much more frequently.

Lawrence Berkeley National Laboratory 1997 Site Environmental Report Vol. I

International Nuclear Information System (INIS)

Thorson, Patrick

1998-01-01

Each year, Ernest Orlando Lawrence Berkeley National Laboratory prepares an integrated report on its environmental programs to satisfy the requirements of U.S. Department of Energy Order 231.1. The Site Environmental Report for 1997 is intended to summarize Berkeley Lab's compliance with environmental standards and requirements, characterize environmental management efforts through surveillance and monitoring activities, and highlight significant programs and efforts for calendar year 1997. This report is structured into three basic areas that cover a general overview of the Laboratory, the status of environmental programs, and the results of the surveillance and monitoring activities, including air quality, surface water, groundwater, sanitary sewer, soil and sediment, vegetation and foodstuffs, radiation dose assessment, and quality assurance. The report is separated into two volumes. Volume I contains the body of the report, a list of references, a list of acronyms and abbreviations, a glossary, Appendix A (NESHAPS annual report), and Appendix B (distribution list for volume I). Volume II contains Appendix C, the individual data results from monitoring programs. Each chapter in volume I begins with an outline of the sections that follow

HydroHillChart – Pelton module. Software used to Calculate the Hill Chart of the Pelton Hydraulic Turbines

Directory of Open Access Journals (Sweden)

Dorian Nedelcu

2015-07-01

Full Text Available The paper presents the HydroHillChart - Pelton module application, used to calculate the hill chart of the Pelton hydraulic turbine models, by processing the data measured on the stand. In addition, the tools offered by the application such as: interface, menu, input data, numerical and graphical results, etc. are described.

The Camp Hill Project: Objectives and Design

Science.gov (United States)

Mattingly, John B.

1976-01-01

Available from: EC 090 474. Outlined are the problems and objectives of Pennsylvania's Camp Hill Project--a program designed to complete psychological needs assessments for juveniles incarcerated at Camp Hill, to develop project policies and guidelines in preparation for meeting with juvenile court judges, and to hire staff. (SBH)

BERKELEY: ALS ring

Energy Technology Data Exchange (ETDEWEB)

Anon.

1993-06-15

Everybody at Lawrence Berkeley Laboratory's Center for Beam Physics is pleased with the rapid progress in commissioning LBL's Advanced Light Source (ALS) electron storage ring, the foundation for this third-generation synchrotron radiation facility. Designed for a maximum current of 400 mA, the ALS storage ring reached 407 mA just 24 days after storing the first beam on 16 March. ALS construction as a US Department of Energy (DOE) national user facility to provide high-brightness vacuum ultra-violet and soft x-ray radiation began in October 1987. One technical requirement marking project completion was to accumulate a 50-mA current in the storage ring. The ALS passed this milestone on 24 March, a week ahead of the official deadline. Once injected, the electron beam decays quasi-exponentially primarily because of interactions with residual gas molecules in the storage-ring vacuum chamber. Eventually, when the pressure in the vacuum chamber with beam decreases toward the expected operating level of 1 nano Torr, it will only be necessary to refill the storage ring at intervals of four to eight hours. At present the vacuum is improving rapidly as surfaces are irradiated (scrubbed) by the synchrotron radiation itself. At 100 mA, beam lifetime was about one hour (9 April)

BERKELEY: ALS ring

International Nuclear Information System (INIS)

Anon.

1993-01-01

Everybody at Lawrence Berkeley Laboratory's Center for Beam Physics is pleased with the rapid progress in commissioning LBL's Advanced Light Source (ALS) electron storage ring, the foundation for this third-generation synchrotron radiation facility. Designed for a maximum current of 400 mA, the ALS storage ring reached 407 mA just 24 days after storing the first beam on 16 March. ALS construction as a US Department of Energy (DOE) national user facility to provide high-brightness vacuum ultra-violet and soft x-ray radiation began in October 1987. One technical requirement marking project completion was to accumulate a 50-mA current in the storage ring. The ALS passed this milestone on 24 March, a week ahead of the official deadline. Once injected, the electron beam decays quasi-exponentially primarily because of interactions with residual gas molecules in the storage-ring vacuum chamber. Eventually, when the pressure in the vacuum chamber with beam decreases toward the expected operating level of 1 nano Torr, it will only be necessary to refill the storage ring at intervals of four to eight hours. At present the vacuum is improving rapidly as surfaces are irradiated (scrubbed) by the synchrotron radiation itself. At 100 mA, beam lifetime was about one hour (9 April)

Annual site environmental report of the Lawrence Berkeley Laboratory

International Nuclear Information System (INIS)

Schleimer, G.E.; Pauer, R.O.

1991-05-01

The Environmental Monitoring Program of the Lawrence Berkeley Laboratory is described. Data for 1990 are presented, and general trends are discussed. The report is organized under the following topics: Environmental Program Overview; Environmental Permits; Environmental Assessments; Environmental Activities; Penetrating Radiation; Airborne Radionuclides; Waterborne Radionuclides; Public Doses Resulting from LBL Operations; Trends -- LBL Environmental Impact; Waterborne Pollutants; Airborne Pollutants; Groundwater Protection; and Quality Assurance. 20 refs., 26 figs., 23 tabs

Nuclear materials teaching and research at the University of California, Berkeley

International Nuclear Information System (INIS)

Olander, D.R.; Roberts, J.T.A.

1985-01-01

In academic nuclear engineering departments, research and teaching in the specialized subdiscipline of nuclear materials is usually a one-person or at best a two-person operation. These subcritical sizes invariably result in inadequate overall representation of the many topics in nuclear materials in the research program of the department, although broader coverage of the field is possible in course offerings. Even in course-work, the full range of materials problems important in nuclear technology cannot be dealt with in detail because the small number of faculty involved restricts staffing to as little as a single summary course and generally no more than three courses in this specialty. The contents of the two nuclear materials courses taught at the University of California at Berkeley are listed. Materials research in most US nuclear engineering departments focuses on irradiation effects on metals, but at UC Berkeley, the principal interest is in the high-temperature materials chemistry of UO 2 fuel and Zircaloy cladding

After runaway: The trans-Hill stage of planetesimal growth

International Nuclear Information System (INIS)

Lithwick, Yoram

2014-01-01

When planetesimals begin to grow by coagulation, they first enter an epoch of runaway, during which the biggest bodies grow faster than all the others. The questions of how runaway ends and what comes next have not been answered satisfactorily. We show that runaway is followed by a new stage—the 'trans-Hill stage'—that commences when the bodies that dominate viscous stirring ('big bodies') become trans-Hill, i.e., when their Hill velocity matches the random speed of the small bodies they accrete. Subsequently, the small bodies' random speed grows in lockstep with the big bodies' sizes, such that the system remains in the trans-Hill state. Trans-Hill growth is crucial for determining the efficiency of growing big bodies, as well as their growth timescale and size spectrum. Trans-Hill growth has two sub-stages. In the earlier one, which occurs while the stirring bodies remain sufficiently small, the evolution is collisionless, i.e., collisional cooling among all bodies is irrelevant. The efficiency of forming big bodies in this collisionless sub-stage is very low, ∼10α << 1, where α ∼ 0.005(a/AU) –1 is the ratio between the physical size of a body and its Hill radius. Furthermore, the size spectrum is flat (equal mass per size decade, i.e., q = 4). This collisionless trans-Hill solution explains results from previous coagulation simulations for both the Kuiper Belt and the asteroid belt. The second trans-Hill sub-stage commences once the stirring bodies grow big enough (>α –1 × the size of the accreted small bodies). After that time, collisional cooling among small bodies controls the evolution. The efficiency of forming big bodies rises and the size spectrum becomes more top heavy. Trans-Hill growth can terminate in one of two ways, depending on the sizes of the small bodies. First, mutual accretion of big bodies can become significant and conglomeration proceeds until half of the total mass is converted into big bodies

A community of scientists: cultivating scientific identity among undergraduates within the Berkeley Compass Project

Science.gov (United States)

Aceves, Ana V.; Berkeley Compass Project

2015-01-01

The Berkeley Compass Project is a self-formed group of graduate and undergraduate students in the physical sciences at UC Berkeley. Our goals are to improve undergraduate physics education, provide opportunities for professional development, and increase retention of students from populations typically underrepresented in the physical sciences. For students who enter as freshmen, the core Compass experience consists of a summer program and several seminar courses. These programs are designed to foster a diverse, collaborative student community in which students engage in authentic research practices and regular self-reflection. Compass encourages undergraduates to develop an identity as a scientist from the beginning of their university experience.

Laboratories for the 21st Century: Case Studies, Molecular Foundry, Berkeley, California

Energy Technology Data Exchange (ETDEWEB)

2010-11-01

This case study provides information on the Molecular Foundry, which incorporates Labs21 principles in its design and construction. The design includes many of the strategies researched at Lawrence Berkeley Laboratory for energy efficient cleanroom and data centers.

Popular Berkeley Lab X-ray Data Booklet reissued

International Nuclear Information System (INIS)

Robinson, Art

2001-01-01

X-ray scientists and synchrotron-radiation users who have been patiently waiting for an updated version of the popular X-Ray Data Booklet last published in 1986 by the Center for X-Ray Optics at the Lawrence Berkeley National Laboratory can breathe a sigh of relief. The venerable ''little orange book'' has now been reissued under the auspices of CXRO and the Advanced Light Source (ALS) with an April printing of 10,000 paper copies and the posting of a Web edition at http://xdb.lbl.gov

Accounting for imperfect detection in Hill numbers for biodiversity studies

Science.gov (United States)

Broms, Kristin M.; Hooten, Mevin B.; Fitzpatrick, Ryan M.

2015-01-01

Hill numbers unify biodiversity metrics by combining several into one expression. For example, species richness, Shannon's diversity index and the Gini–Simpson index are a few of the most used diversity measures, and they can be expressed as Hill numbers. Traditionally, Hill numbers have been calculated from relative abundance data, but the expression has been modified to use incidence data as well. We demonstrate an approach for estimating Hill numbers using an occupancy modelling framework that accounts for imperfect detection.

A language for image processing HILLS and its supporting system SDIP

International Nuclear Information System (INIS)

Suzuki, H.; Toriwaki, J.

1984-01-01

This paper presents a language HILLS and its supporting system SDIP for image processing. HILLS is a key-word type language for describing image processing procedures by using subroutine packages SLIP and SPIDER. SDIP, written in FORTRAN to keep portability, supports programming by HILLS in interactive mode including functions such as editing, translating HILLS into FORTRAN, error detection, and providing manual information. Results of preliminary experiments suggest that HILLS and SDIP are very useful tools for beginners and researchers in application fields of image processing to develop desired image analysis procedures

Ernest Orlando Berkeley National Laboratory - Fundamental and applied research on lean premixed combustion

International Nuclear Information System (INIS)

Cheng, Robert K.

1999-01-01

Ernest Orland Lawrence Berkeley National Laboratory (Berkeley Lab) is the oldest of America's national laboratories and has been a leader in science and engineering technology for more than 65 years, serving as a powerful resource to meet Us national needs. As a multi-program Department of Energy laboratory, Berkeley Lab is dedicated to performing leading edge research in the biological, physical, materials, chemical, energy, environmental and computing sciences. Ernest Orlando Lawrence, the Lab's founder and the first of its nine Nobel prize winners, invented the cyclotron, which led to a Golden Age of particle physics and revolutionary discoveries about the nature of the universe. To this day, the Lab remains a world center for accelerator and detector innovation and design. The Lab is the birthplace of nuclear medicine and the cradle of invention for medical imaging. In the field of heart disease, Lab researchers were the first to isolate lipoproteins and the first to determine that the ratio of high density to low density lipoproteins is a strong indicator of heart disease risk. The demise of the dinosaurs--the revelation that they had been killed off by a massive comet or asteroid that had slammed into the Earth--was a theory developed here. The invention of the chemical laser, the unlocking of the secrets of photosynthesis--this is a short preview of the legacy of this Laboratory

27 CFR 9.162 - Sta. Rita Hills.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Sta. Rita Hills. 9.162.... Rita Hills. (a) Name. The name of the viticultural area described in this section is “Sta. Rita Hills”. For purposes of part 4 of this chapter, “Sta. Rita Hills” is a term of viticultural significance. (b...

Biogeography of the Shimba Hills ecosystem herpetofauna in Kenya.

Science.gov (United States)

Malonza, Patrick K; Mulwa, David M; Nyamache, Joash O; Jones, Georgina

2018-03-18

The Shimba Hills ecosystem along the south coast of Kenya is a key East African biodiversity hotspot. Historically, it is biogeographically assignable to the East African coastal biome. We examined the current Shimba Hills herpetofauna and their zoogeographical affinities to the coastal forests and nearby Eastern Arc Mountains biodiversity hotspots. The key studied sites included the Shimba Hills National Reserve, forest reserves, Kaya forests, and adjacent private land. Data on herpetofaunal richness were obtained from recent field surveys, literature, and specimens held at the National Museums of Kenya, Herpetology Section Collection, Nairobi. The Makadara, Mwele, and Longo-Mwagandi forests within the Shimba Hills National Reserve hosted the highest number of unique and rare species. Generally, the forest reserves and Kaya forests were important refuges for forest-associated species. On private land, Mukurumudzi Dam riparian areas were the best amphibian habitat and were host to three IUCN (Red List) Endangered-EN amphibian species, namely, Boulengerula changamwensis, Hyperolius rubrovermiculatus, and Afrixalus sylvaticus, as well as one snake species Elapsoidea nigra. Using herpetofauna as zoogeographic indicators, the Shimba Hills were determined to be at a crossroads between the coastal forests (13 endemic species) and the Eastern Arc Mountains (seven endemic species). Most of the Eastern Arc Mountains endemic species were from recent records, and thus more are likely to be found in the future. This 'hybrid' species richness pattern is attributable to the hilly topography of the Shimba Hills and their proximity to the Indian Ocean. This has contributed to the Shimba Hills being the richest herpetofauna area in Kenya, with a total of 89 and 36 reptile and amphibian species, respectively. Because of its unique zoogeography, the Shimba Hills ecosystem is undoubtedly a key biodiversity area for conservation investment.

Audio-magnetotelluric (AMT) study to investigate the genesis of Mujil hill

Science.gov (United States)

Rahmania, Suryanto, Wiwit

2017-07-01

Gunung Mujil is an isolated hill located near Pondoworejo village, Kalibawang sub-district, Kulon Progo district, and Special Province of Yogyakarta. The hill is part of the eastern Kulon Progo mountain range extended relatively in the North-South direction. The lithology of the hill consists of andesite breccia and it's similar with the Old Andesite Formation that built the Kulon Progo Mountains. There are at least two hypothesis about the genesis and the formation mechanism of this hill, (1) it was formed by debris mass from Kulon Progo Mountains, and (2) ) it was formed by an intrusion. Our study intended to determine the subsurface resistivity below the hill and to relating those results to with the scenario of the genesis of the Mujil hill. We conducted Audio-magnetotellurics (AMT) measurements along two lines survey crossing the Mujil hill consisting of 20 measurements. Since the measurements are located near the villages, most of the data has a fair to bad quality and only one station yielded an excellent data. A 1D Forward modeling was then applied to find best-fit model of the AMT data. The results shows that the Mujil hill was built by debris mass of the Old Andesite Formation from Kulon Progo mountain which is represented by a lower resistivity value under the Mujil hill.

Hume, Mill, Hill, and the sui generis epidemiologic approach to causal inference.

Science.gov (United States)

Morabia, Alfredo

2013-11-15

The epidemiologic approach to causal inference (i.e., Hill's viewpoints) consists of evaluating potential causes from the following 2, noncumulative angles: 1) established results from comparative, observational, or experimental epidemiologic studies; and 2) reviews of nonepidemiologic evidence. It does not involve statements of statistical significance. The philosophical roots of Hill's viewpoints are unknown. Superficially, they seem to descend from the ideas of Hume and Mill. Hill's viewpoints, however, use a different kind of evidence and have different purposes than do Hume's rules or Mill's system of logic. In a nutshell, Hume ignores comparative evidence central to Hill's viewpoints. Mill's logic disqualifies as invalid nonexperimental evidence, which forms the bulk of epidemiologic findings reviewed from Hill's viewpoints. The approaches by Hume and Mill cannot corroborate successful implementations of Hill's viewpoints. Besides Hume and Mill, the epidemiologic literature is clueless about a plausible, pre-1965 philosophical origin of Hill's viewpoints. Thus, Hill's viewpoints may be philosophically novel, sui generis, still waiting to be validated and justified.

Weak Properties and Robustness of t-Hill Estimators

Czech Academy of Sciences Publication Activity Database

Jordanova, P.; Fabián, Zdeněk; Hermann, P.; Střelec, L.; Rivera, A.; Girard, S.; Torres, S.; Stehlík, M.

2016-01-01

Roč. 19, č. 4 (2016), s. 591-626 ISSN 1386-1999 Institutional support: RVO:67985807 Keywords : asymptotic properties of estimators * point estimation * t-Hill estimator * t-lgHill estimator Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 1.679, year: 2016

Catalog of research projects at Lawrence Berkeley Laboratory, 1985

International Nuclear Information System (INIS)

1985-01-01

This Catalog has been created to aid in the transfer of technology from the Lawrence Berkeley Laboratory to potential users in industry, government, universities, and the public. The projects are listed for the following LBL groups: Accelerator and Fusion Research Division, Applied Science Division, Biology and Medicine Division, Center for Advanced Materials, Chemical Biodynamics Division, Computing Division, Earth Sciences Division, Engineering and Technical Services Division, Materials and Molecular Research Division, Nuclear Science Division, and Physics Division

Catalog of research projects at Lawrence Berkeley Laboratory, 1985

Energy Technology Data Exchange (ETDEWEB)

1985-01-01

This Catalog has been created to aid in the transfer of technology from the Lawrence Berkeley Laboratory to potential users in industry, government, universities, and the public. The projects are listed for the following LBL groups: Accelerator and Fusion Research Division, Applied Science Division, Biology and Medicine Division, Center for Advanced Materials, Chemical Biodynamics Division, Computing Division, Earth Sciences Division, Engineering and Technical Services Division, Materials and Molecular Research Division, Nuclear Science Division, and Physics Division.

The man and the hill

Science.gov (United States)

Leopold, Luna Bergere

1962-01-01

He was sitting on a large slab of rock. As he looked at the cloud of dust hanging hazily on the horizon, the piece of antler and the block of flint he held in his hand hung as if they were suspended from their previous rapid motion. The man gazed intently across the swaying grass which rose in wave-like billows across the distant hills. What was that dust - a herd of buffalo, a band of hunters, or were coyotes chasing the antelope again? After watching for a while he started again to chip the flint with a rapid twisting motion of the bone in his right hand. The little chips of flint fell in the grass before him. It is the same hill but the scene has changed. Seated on the same rock, holding the reins of a saddle horse, a man dressed in buckskin took the fur cap off his head and wiped his brow. He was looking intently across a brown and desolate landscape at a cloud of dust on the far horizon. Was it the hostile tribe of Indians? It could be buffalo. Nervously he kicked at the ground with the deerhide moccasin, pushing the flint chips out of the way. He wiped the dust from his long rifle. What a terrible place - no water, practically no grass, everything bare and brown. Now at sunset, slanting across the hills green with springtime, a cowman sits on a big rock, pushes his sombrero back on his head, and looks across the valley at a large but quiet herd of stock, moving slowly as each steer walks from one lush patch of grass to another, nibbling. Suddenly he stood up. Far on the horizon some dark objects were moving. Is it the sheepmen? Could it be the stage coach from Baggs to the Sweetwater Crossing?Same hill - a gray truck was grinding slowly toward the summit. It pulled up near a small fenced enclosure where there were some instruments painted a bright silver color. A man stepped out of the truck and turned to his younger companion, "You've never found an arrowhead? Maybe you have never thought about it correctly. If you want to find where an Indian camped long

Eight-fold quantum states blossom in a high-temperature superconductor

CERN Multimedia

2003-01-01

"Researchers based at Lawrence Berkeley National Laboratory and the University of California at Berkeley have used a scanning tunneling microscope (STM) to reveal eight-fold patterns of quasiparticle interference in the high-temperature superconductor Bi-2212 (bismuth strontium calcium copper oxide)" (2 pages).

Penyelesaian Masalah 8-Puzzle dengan Algoritma Steepest-Ascent Hill Climbing

Directory of Open Access Journals (Sweden)

David Abraham

2016-03-01

Full Text Available 8 puzzle merupakan salah satu implementasi dari Artificial Intelegence. Dalam proses penyelesaiannya banyak terdapat algoritma-algoritma pencarian yang dapat diterapkan. Solusi 8 puzzle akan lebih cepat diperoleh jika digunakan prinsip array dengan variasi algoritma Steepest-Ascent Hill Climbing (Hill Climbing dengan memilih kemiringan yang paling tajam / curam dengan parameter heuristik posisi yang benar dan heuristik jarak serta dikombinasikan dengan LogList sebagai penyimpanan state state yang pernah dilalui untuk menanggulangi permasalah pada algoritma hill climbing itu sendiri dan terhindar dari looping state yang pernah dilalui. Metode-metode yang termasuk ke dalam teknik pencarian yang berdasarkan pada fungsi heuristik salah satu diantaranya adalah Hill Climbing, Best First Search, A* (A Bintang. Loglist merupakan tempat penyimpanan setiap kunjungan dari state-state puzzle yang telah dilakukan untuk menghindari looping atau pengulangan terhadap state yang pernah dilalui. Untuk menanggulangi permasalahan pada SteepestAscent Hill Climbing.

Lawrence Berkeley National Laboratory 1995 site environmental report

Energy Technology Data Exchange (ETDEWEB)

Balgobin, D.; Javandel, I.; Lackner, G.; Smith, C.; Thorson, P.; Tran, H.

1996-07-01

The 1995 Site Environmental Report summarizes environmental activities at the Ernest Orlando Lawrence Berkeley National Laboratory (LBNL) for the 1995 calendar year. The report strives to present environmental data in a manner that characterizes the performance and compliance status of the environmental management programs. The report also discusses significant highlights and plans of these programs. Topics discussed include: environmental monitoring, environmental compliance programs, air quality, water quality, ground water protection, sanitary sewer monitoring, soil and sediment quality, vegetation and foodstuffs monitoring, and special studies which include preoperational monitoring of building 85 and 1995 sampling results, radiological dose assessment, and quality assessment.

Lawrence Berkeley National Laboratory 1995 site environmental report

International Nuclear Information System (INIS)

Balgobin, D.; Javandel, I.; Lackner, G.; Smith, C.; Thorson, P.; Tran, H.

1996-07-01

The 1995 Site Environmental Report summarizes environmental activities at the Ernest Orlando Lawrence Berkeley National Laboratory (LBNL) for the 1995 calendar year. The report strives to present environmental data in a manner that characterizes the performance and compliance status of the environmental management programs. The report also discusses significant highlights and plans of these programs. Topics discussed include: environmental monitoring, environmental compliance programs, air quality, water quality, ground water protection, sanitary sewer monitoring, soil and sediment quality, vegetation and foodstuffs monitoring, and special studies which include preoperational monitoring of building 85 and 1995 sampling results, radiological dose assessment, and quality assessment

Lawrence Berkeley Laboratory upgrading approaches to existing facilities

International Nuclear Information System (INIS)

Engle, H.M. Jr.

1985-01-01

The Lawrence Berkeley Laboratory Plant Engineering Department instituted a seismic risk investigation and seismic upgrade program in 1970. This paper covers the upgrade of two buildings with dissimilar framing systems; Building No. 10, a World War II vintage heavy timber frame building, and Building No. 80, a steel frame structure constructed in 1954. The seismic upgrade task for both structures required that the buildings be kept in service during rehabilitation with a minimum of disruption to occupants. Rehabilitations were phased over two and three year periods with construction management and supervision performed by LBL Plant Engineering staff

Tunnel - history of

International Nuclear Information System (INIS)

1998-11-01

This book introduces history of tunnel in ancient times, the middle ages and modern times, survey of tunnel and classification of bedrock like environment survey of position, survey of the ground, design of tunnel on basic thing of the design, and design of tunnel of bedrock, analysis of stability of tunnel and application of the data, construction of tunnel like lattice girder and steel fiber reinforced shot crete, and maintenance control and repair of tunnel.

Newtonian and pseudo-Newtonian Hill problem

International Nuclear Information System (INIS)

Steklain, A.F.; Letelier, P.S.

2006-01-01

A pseudo-Newtonian Hill problem based on the Paczynski-Wiita pseudo-Newtonian potential that reproduces general relativistic effects is presented and compared with the usual Newtonian Hill problem. Poincare maps, Lyapunov exponents and fractal escape techniques are employed to study bounded and unbounded orbits. In particular we consider the systems composed by Sun, Earth and Moon and composed by the Milky Way, the M2 cluster and a star. We find that some pseudo-Newtonian systems-including the M2 system-are more stable than their Newtonian equivalent

Access to public drinking water fountains in Berkeley, California: a geospatial analysis.

Science.gov (United States)

Avery, Dylan C; Smith, Charlotte D

2018-01-24

In January 2015, Berkeley, California became the first city in the Unites States to impose a tax on sugar-sweetened beverages. The tax is intended to discourage purchase of sugary beverages and promote consumption of healthier alternatives such as tap water. The goal of the study was to assess the condition of public drinking water fountains and determine if there is a difference in access to clean, functioning fountains based on race or socio-economic status. A mobile-GIS App was created to locate and collect data on existing drinking water fountains in Berkeley, CA. Demographic variables related to race and socio-economic status (SES) were acquired from the US Census - American Community Survey database. Disparities in access to, or condition of drinking water fountains relative to demographics was explored using spatial analyses. Spatial statistical-analysis was performed to estimate demographic characteristics of communities near the water fountains and logistic regression was used to examine the relationship between household median income or race and condition of fountain. Although most fountains were classified as functioning, some were dirty, clogged, or both dirty and clogged. No spatial relationships between demographic characteristics and fountain conditions were observed. All geo-located data and a series of maps were provided to the City of Berkeley and the public. The geo-database created as an outcome of this study is useful for prioritizing maintenance of existing fountains and planning the locations of future fountains. The methodologies used for this study could be applied to a wide variety of asset inventory and assessment projects such as clinics or pharmaceutical dispensaries, both in developed and developing countries.

Spectral parameter power series representation for Hill's discriminant

International Nuclear Information System (INIS)

Khmelnytskaya, K.V.; Rosu, H.C.

2010-01-01

We establish a series representation of the Hill discriminant based on the spectral parameter power series (SPPS) recently introduced by Kravchenko. We also show the invariance of the Hill discriminant under a Darboux transformation and employing the Mathieu case the feasibility of this type of series for numerical calculations of the eigenspectrum.

Typical Underwater Tunnels in the Mainland of China and Related Tunneling Technologies

Directory of Open Access Journals (Sweden)

Kairong Hong

2017-12-01

Full Text Available In the past decades, many underwater tunnels have been constructed in the mainland of China, and great progress has been made in related tunneling technologies. This paper presents the history and state of the art of underwater tunnels in the mainland of China in terms of shield-bored tunnels, drill-and-blast tunnels, and immersed tunnels. Typical underwater tunnels of these types in the mainland of China are described, along with innovative technologies regarding comprehensive geological prediction, grouting-based consolidation, the design and construction of large cross-sectional tunnels with shallow cover in weak strata, cutting tool replacement under limited drainage and reduced pressure conditions, the detection and treatment of boulders, the construction of underwater tunnels in areas with high seismic intensity, and the treatment of serious sedimentation in a foundation channel of immersed tunnels. Some suggestions are made regarding the three potential great strait-crossing tunnels—the Qiongzhou Strait-Crossing Tunnel, Bohai Strait-Crossing Tunnel, and Taiwan Strait-Crossing Tunnel—and issues related to these great strait-crossing tunnels that need further study are proposed. Keywords: Underwater tunnel, Strait-crossing tunnel, Shield-bored tunnel, Immersed tunnel, Drill and blast

Higher Retail Prices of Sugar-Sweetened Beverages 3 Months After Implementation of an Excise Tax in Berkeley, California.

Science.gov (United States)

Falbe, Jennifer; Rojas, Nadia; Grummon, Anna H; Madsen, Kristine A

2015-11-01

We assessed the short-term ability to increase retail prices of the first US 1-cent-per-ounce excise tax on the distribution of sugar-sweetened beverages (SSBs), which was implemented in March 2015 by Berkeley, California. In 2014 and 2015, we examined pre- to posttax price changes of SSBs and non-SSBs in a variety of retailers in Berkeley and in the comparison cities Oakland and San Francisco, California. We examined price changes by beverage, brand, size, and retailer type. For smaller beverages (≤ 33.8 oz), price increases (cents/oz) in Berkeley relative to those in comparison cities were 0.69 (95% confidence interval [CI] = 0.36, 1.03) for soda, 0.47 (95% CI = 0.08, 0.87) for fruit-flavored beverages, and 0.47 (95% CI = 0.25, 0.69) for SSBs overall. For 2-liter bottles and multipacks of soda, relative price increases were 0.46 (95% CI = 0.03, 0.89) and 0.49 (95% CI = 0.21, 0.77). We observed no relative price increases for nontaxed beverages overall. Approximately 3 months after the tax was implemented, SSB retail prices increased more in Berkeley than in nearby cities, marking a step in the causal pathway between the tax and reduced SSB consumption.

Direct, coherent and incoherent intermediate state tunneling and scanning tunnel microscopy (STM)

International Nuclear Information System (INIS)

Halbritter, J.

1997-01-01

Theory and experiment in tunneling are still qualitative in nature, which hold true also for the latest developments in direct-, resonant-, coherent- and incoherent-tunneling. Those tunnel processes have recently branched out of the field of ''solid state tunnel junctions'' into the fields of scanning tunnel microscopy (STM), single electron tunneling (SET) and semiconducting resonant tunnel structures (RTS). All these fields have promoted the understanding of tunneling in different ways reaching from the effect of coherence, of incoherence and of charging in tunneling, to spin flip or inelastic effects. STM allows not only the accurate measurements of the tunnel current and its voltage dependence but, more importantly, the easy quantification via the (quantum) tunnel channel conductance and the distance dependence. This new degree of freedom entering exponentially the tunnel current allows an unique identification of individual tunnel channels and their quantification. In STM measurements large tunnel currents are observed for large distances d > 1 nm explainable by intermediate state tunneling. Direct tunneling with its reduced tunnel time and reduced off-site Coulomb charging bridges distances below 1 nm, only. The effective charge transfer process with its larger off-site and on-site charging at intermediate states dominates tunnel transfer in STM, biology and chemistry over distances in the nm-range. Intermediates state tunneling becomes variable range hopping conduction for distances larger than d > 2 nm, for larger densities of intermediate states n 1 (ε) and for larger temperatures T or voltages U, still allowing high resolution imaging

Plants profile of Malakand Pass Hills, District Malakand, Pakistan

African Journals Online (AJOL)

use

2011-11-21

Nov 21, 2011 ... famous Malakand fort guards the road on both sides of the pass. Malakand is a ... Underneath Malakand Hills, the waters of the River Swat ... southern sloping faces of the hills. They speak ...... Pinus roxburghii Sarg. Antidote ...

Construction and operation of replacement hazardous waste handling facility at Lawrence Berkeley Laboratory

International Nuclear Information System (INIS)

1992-09-01

The US Department of Energy (DOE) has prepared an environmental assessment (EA), DOE/EA-0423, for the construction and operation of a replacement hazardous waste handling facility (HWHF) and decontamination of the existing HWHF at Lawrence Berkeley Laboratory (LBL), Berkeley, California. The proposed facility would replace several older buildings and cargo containers currently being used for waste handling activities and consolidate the LBL's existing waste handling activities in one location. The nature of the waste handling activities and the waste volume and characteristics would not change as a result of construction of the new facility. Based on the analysis in the EA, DOE has determined that the proposed action would not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969, 42 USC. 4321 et seq. Therefore, an environmental impact statement is not required

Phosphorus forms in soils of Oban Hills, Akamkpa, Cross River State ...

African Journals Online (AJOL)

Oban Hills is located at Akamkpa in the Southern Senatorial District of Cross River, State, Nigeria. Phosphorus (P)-rich soil from the Hills is expected to have an effect on retention and distribution in the highly acidic soils surrounding the area inundated for several years. Phosphorus forms in the soils of the Hills varied with ...

Photovoltaics - 10 years after Cherry Hill

Science.gov (United States)

Ralph, E. L.

The status of R&D programs connected with photovoltaic (PV) systems 10 years after the Cherry Hill workshop on 'Photovoltaic Conversion of Solar Energy for Terrestrial Applications' is assessed. The five categories of research recommended by the Cherry Hill Workshop are listed in a table together with their recommended research budget allocations. The workshop categories include: single-crystal Si cells; poly-Si cells; systems and diagnostics. Categories for thin film CdS/Cu2S and CuInSe2 cells are also included. The roles of government and private utility companies in providing adequate financial support for PV research programs is emphasized.

78 FR 73187 - Black Hills National Forest Advisory Board

Science.gov (United States)

2013-12-05

... DEPARTMENT OF AGRICULTURE Forest Service Black Hills National Forest Advisory Board AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Black Hills National Forest Advisory Board (Board... all members of the Advisory Board; (2) provide orientation to Board Members on Basic Laws governing...

Funny hills in pion spectra from heavy-ion collisions

International Nuclear Information System (INIS)

Rasmussen, J.O.

1982-03-01

A discussion of some of the systematic features of the pion spectra in heavy-ions reactions is given. A discussion of the hills and valleys in heavy ion pion spectra that show up at the lower pion energies is given. The following topics are discussed: (1) three kinds of funny hills; (2) π - / + ratios near center of mass; (3) new Monte Carlo studies of charged pion spectra; and (4) pion orbiting about fireballs and Bose-Einstein behavior as explanation for the mid-rapidity P/sub perpendicular to/ approx. = 0.4 to 0.5 m/sub π/c hill

Berkeley Foundation for Opportunities in Information Technology: A Decade of Broadening Participation

Science.gov (United States)

Crutchfield, Orpheus S. L.; Harrison, Christopher D.; Haas, Guy; Garcia, Daniel D.; Humphreys, Sheila M.; Lewis, Colleen M.; Khooshabeh, Peter

2011-01-01

The Berkeley Foundation for Opportunities in Information Technology is a decade-old endeavor to expose pre-college young women and underrepresented racial and ethnic minorities to the fields of computer science and engineering, and prepare them for rigorous, university-level study. We have served more than 150 students, and graduated more than 65…

Wind Tunnel Modeling Of Wind Flow Over Complex Terrain

Science.gov (United States)

Banks, D.; Cochran, B.

2010-12-01

This presentation will describe the finding of an atmospheric boundary layer (ABL) wind tunnel study conducted as part of the Bolund Experiment. This experiment was sponsored by Risø DTU (National Laboratory for Sustainable Energy, Technical University of Denmark) during the fall of 2009 to enable a blind comparison of various air flow models in an attempt to validate their performance in predicting airflow over complex terrain. Bohlund hill sits 12 m above the water level at the end of a narrow isthmus. The island features a steep escarpment on one side, over which the airflow can be expected to separate. The island was equipped with several anemometer towers, and the approach flow over the water was well characterized. This study was one of only two only physical model studies included in the blind model comparison, the other being a water plume study. The remainder were computational fluid dynamics (CFD) simulations, including both RANS and LES. Physical modeling of air flow over topographical features has been used since the middle of the 20th century, and the methods required are well understood and well documented. Several books have been written describing how to properly perform ABL wind tunnel studies, including ASCE manual of engineering practice 67. Boundary layer wind tunnel tests are the only modelling method deemed acceptable in ASCE 7-10, the most recent edition of the American Society of Civil Engineers standard that provides wind loads for buildings and other structures for buildings codes across the US. Since the 1970’s, most tall structures undergo testing in a boundary layer wind tunnel to accurately determine the wind induced loading. When compared to CFD, the US EPA considers a properly executed wind tunnel study to be equivalent to a CFD model with infinitesimal grid resolution and near infinite memory. One key reason for this widespread acceptance is that properly executed ABL wind tunnel studies will accurately simulate flow separation

"A Woman's World": The University of California, Berkeley, during the Second World War

Science.gov (United States)

Dorn, Charles

2008-01-01

During World War II, female students at the University of California, Berkeley--then the most populous undergraduate campus in American higher education--made significant advances in collegiate life. In growing numbers, women enrolled in male-dominated academic programs, including mathematics, chemistry, and engineering, as they prepared for…

Monitoring pilot projects on bored tunnelling : The Second Heinenoord Tunnel and the Botlek Rail Tunnel

NARCIS (Netherlands)

Bakker, K.J.; De Boer, F.; Admiraal, J.B.M.; Van Jaarsveld, E.P.

1999-01-01

Two pilot projects for bored tunnelling in soft soil have been undertaken in the Netherlands. The monitoring was commissioned under the authority of the Centre for Underground Construction (COB). A description of the research related to the Second Heinenoord Tunnel and the Botlek Rail Tunnel will be

EMG activities and plantar pressures during ski jumping take-off on three different sized hills.

Science.gov (United States)

Virmavirta, M; Perttunen, J; Komi, P V

2001-04-01

Different profiles of ski jumping hills have been assumed to make the initiation of take-off difficult especially when moving from one hill to another. Neuromuscular adaptation of ski jumpers to the different jumping hills was examined by measuring muscle activation and plantar pressure of the primary take-off muscles on three different sized hills. Two young ski jumpers volunteered as subjects and they performed several trials from each hill (K-35 m, K-65 m and K-90 m) with the same electromyographic (EMG) electrode and insole pressure transducer set-up. The results showed that the differences in plantar pressure and EMGs between the jumping hills were smaller than expected for both jumpers. The small changes in EMG amplitudes between the hills support the assumption that the take-off was performed with the same intensity on different jumping hills and the timing of the gluteus EMG demonstrates well the similarity of the muscle activation on different hills. On the basis of the results obtained it seems that ski jumping training on small hills does not disturb the movement patterns for bigger hills and can also be helpful for special take-off training with low speed.

Searching for multiple stellar populations in the massive, old open cluster Berkeley 39

Science.gov (United States)

Bragaglia, A.; Gratton, R. G.; Carretta, E.; D'Orazi, V.; Sneden, C.; Lucatello, S.

2012-12-01

The most massive star clusters include several generations of stars with a different chemical composition (mainly revealed by an Na-O anti-correlation) while low-mass star clusters appear to be chemically homogeneous. We are investigating the chemical composition of several clusters with masses of a few 104 M⊙ to establish the lower mass limit for the multiple stellar population phenomenon. Using VLT/FLAMES spectra we determine abundances of Fe, O, Na, and several other elements (α, Fe-peak, and neutron-capture elements) in the old open cluster Berkeley 39. This is a massive open cluster: M ~ 104 M⊙, approximately at the border between small globular clusters and large open clusters. Our sample size of about 30 stars is one of the largest studied for abundances in any open cluster to date, and will be useful to determine improved cluster parameters, such as age, distance, and reddening when coupled with precise, well-calibrated photometry. We find that Berkeley 39 is slightly metal-poor, ⟨[Fe/H]⟩ = -0.20, in agreement with previous studies of this cluster. More importantly, we do not detect any star-to-star variation in the abundances of Fe, O, and Na within quite stringent upper limits. The rms scatter is 0.04, 0.10, and 0.05 dex for Fe, O, and Na, respectively. This small spread can be entirely explained by the noise in the spectra and by uncertainties in the atmospheric parameters. We conclude that Berkeley 39 is a single-population cluster. Based on observations collected at ESO telescopes under programme 386.B-0009.Tables 2 and 3 are available in electronic form at http://www.aanda.org

Gilbert Newton Lewis: his influence on physical-organic chemists at Berkeley

Energy Technology Data Exchange (ETDEWEB)

Calvin, M.

1982-03-01

A review is presented of the historical contributions of Gilbert N. Lewis to science and a discussion of the influence of Lewis on the research of the members of the physical-organic staff at Berkeley, including Melvin Calvin, during the twenties, thirties and forties. Some specific examples are discussed. Also, the effect of Lewis, his science and administrative concepts in the creation of excellence in a department of chemistry are reviewed.

Gilbert Newton Lewis: his influence on physical-organic chemists at Berkeley

International Nuclear Information System (INIS)

Calvin, M.

1982-03-01

A review is presented of the historical contributions of Gilbert N. Lewis to science and a discussion of the influence of Lewis on the research of the members of the physical-organic staff at Berkeley, including Melvin Calvin, during the twenties, thirties and forties. Some specific examples are discussed. Also, the effect of Lewis, his science and administrative concepts in the creation of excellence in a department of chemistry are reviewed

Changes in prices, sales, consumer spending, and beverage consumption one year after a tax on sugar-sweetened beverages in Berkeley, California, US: A before-and-after study.

Directory of Open Access Journals (Sweden)

Lynn D Silver

2017-04-01

Full Text Available Taxes on sugar-sweetened beverages (SSBs meant to improve health and raise revenue are being adopted, yet evaluation is scarce. This study examines the association of the first penny per ounce SSB excise tax in the United States, in Berkeley, California, with beverage prices, sales, store revenue/consumer spending, and usual beverage intake.Methods included comparison of pre-taxation (before 1 January 2015 and first-year post-taxation (1 March 2015-29 February 2016 measures of (1 beverage prices at 26 Berkeley stores; (2 point-of-sale scanner data on 15.5 million checkouts for beverage prices, sales, and store revenue for two supermarket chains covering three Berkeley and six control non-Berkeley large supermarkets in adjacent cities; and (3 a representative telephone survey (17.4% cooperation rate of 957 adult Berkeley residents. Key hypotheses were that (1 the tax would be passed through to the prices of taxed beverages among the chain stores in which Berkeley implemented the tax in 2015; (2 sales of taxed beverages would decline, and sales of untaxed beverages would rise, in Berkeley stores more than in comparison non-Berkeley stores; (3 consumer spending per transaction (checkout episode would not increase in Berkeley stores; and (4 self-reported consumption of taxed beverages would decline. Main outcomes and measures included changes in inflation-adjusted prices (cents/ounce, beverage sales (ounces, consumers' spending measured as store revenue (inflation-adjusted dollars per transaction in two large chains, and usual beverage intake (grams/day and kilocalories/day. Tax pass-through (changes in the price after imposition of the tax for SSBs varied in degree and timing by store type and beverage type. Pass-through was complete in large chain supermarkets (+1.07¢/oz, p = 0.001 and small chain supermarkets and chain gas stations (1.31¢/oz, p = 0.004, partial in pharmacies (+0.45¢/oz, p = 0.03, and negative in independent corner stores and

SPICE modelling of magnetic tunnel junctions written by spin-transfer torque

Energy Technology Data Exchange (ETDEWEB)

Guo, W; Prenat, G; De Mestier, N; Baraduc, C; Dieny, B [SPINTEC, UMR(8191), INAC, CEA/CNRS/UJF, 17 Av. des Martyrs, 38054 Grenoble Cedex 9 (France); Javerliac, V; El Baraji, M, E-mail: guillaume.prenat@cea.f [CROCUS Technology, 5 Place Robert Schuman, 38025 Grenoble (France)

2010-06-02

Spintronics aims at extending the possibility of conventional electronics by using not only the charge of the electron but also its spin. The resulting spintronic devices, combining the front-end complementary metal oxide semiconductor technology of electronics with a magnetic back-end technology, employ magnetic tunnel junctions (MTJs) as core elements. With the intent of simulating a circuit without fabricating it first, a reliable MTJ electrical model which is applicable to the standard SPICE (Simulation Program with Integrated Circuit Emphasis) simulator is required. Since such a model was lacking so far, we present a MTJ SPICE model whose magnetic state is written by using the spin-transfer torque effect. This model has been developed in the C language and validated on the Cadence Virtuoso Platform with a Spectre simulator. Its operation is similar to that of the standard BSIM (Berkeley Short-channel IGFET Model) SPICE model of the MOS transistor and fully compatible with the SPICE electrical simulator. The simulation results obtained using this model have been found in good accord with those theoretical macrospin calculations and results.

Fun and games in Berkeley: the early years (1956-2013).

Science.gov (United States)

Tinoco, Ignacio

2014-01-01

Life at Berkeley for the past 57 years involved research on the thermodynamics, kinetics, and spectroscopic properties of RNA to better understand its structures, interactions, and functions. We (myself and all the graduate students and postdocs who shared in the fun) began with dinucleoside phosphates and slowly worked our way up to megadalton-sized RNA molecular motors. We used UV absorption, circular dichroism, circular intensity differential scattering, fluorescence, NMR, and single-molecule methods. We learned a lot and had fun doing it.

Particle production in high energy nucleus--nucleus experiments at Berkeley

International Nuclear Information System (INIS)

Schroeder, L.S.

1976-09-01

A review of high energy nucleus-nucleus experiments performed at the Berkeley Bevalac is presented. Earlier results on projectile and target fragmentation and pion production are briefly summarized. More recent results on Coulomb effects in projectile fragmentation, heavy ion total cross-sections, γ-ray production, and charged particle multiplicities are presented. Also, recent experiments which may shed light on phenomena arising from the central collision of two energetic nuclei, including recent evidence for and against the observation of nuclear shock waves, are reviewed

Berkeley 51 Kümesinin Temel ve Astrofiziksel Parametrelerinin Belirlenmesi

Directory of Open Access Journals (Sweden)

İnci Akkaya Oralhan

2016-10-01

Full Text Available Galaksimizin birinci çeyreğinde bulunan ve daha önce çok az çalışılmış açık yıldız kümelerinden biri olan Berkeley 51 kümesinin temel astrofiziksel ve yapısal parametreleri CCD UBV(RIC ve 2MASS JHKS verileri kullanılarak elde edilmiştir. Kümeye ait CCD UBV(RIC verileri Meksika’da bulunan San Pedro Martir Ulusal Gözlemevi’nden 84cm’lik teleskop ile alınmıştır. Küme üyeliklerinin belirlenmesinde ise PPMXL kataloğundaki öz hareket verileri kullanılmıştır. Buna küre bu küme için elde edilen limit yarıçap Rlim=2.5 yay dakikası, kızarma E(B-V=0.85±0.05 kadir, E(J-H=0.28±0.02 kadir, uzaklık modülü DM=(m-M0=10.66±0.04 pc, uzaklığı d=1355±27 pc ve logaritmik yaş log(A=9.54±0.03 Myıl olarak bulunmuştur. Küme için ilk kez bulunan metal ve ağır element bolluğu ise sırasıyla [Fe/H]=-0.38 ve Z=0.006 olarak elde edilmiştir.Anahtar kelimeler: Açık yıldız kümeleri-Berkeley 51

Clinical results of stereotactic hellium-ion radiosurgery of the pituitary gland at Lawrence Berkeley Laboratory

International Nuclear Information System (INIS)

Levy, R.P.; Fabrikant, J.I.; Lyman, J.T.; Frankel, K.A.; Phillips, M.H.; Lawrence, J.H.; Tobias, C.A.

1989-12-01

The first therapeutic clinical trial using accelerated heavy-charged particles in humans was performed at Lawrence Berkeley Laboratory (LBL) for the treatment of various endocrine and metabolic disorders of the pituitary gland, and as suppressive therapy for adenohypophyseal hormone-responsive carcinomas and diabetic retinopathy. In acromegaly, Cushing's disease, Nelson's syndrome and prolactin-secreting tumors, the therapeutic goal in the 433 patients treated has been to destroy or inhibit the growth of the pituitary tumor and control hormonal hypersecretion, while preserving a functional rim of tissue with normal hormone-secreting capacity, and minimizing neurologic injury. An additional group of 34 patients was treated for nonsecreting chromophobe adenomas. This paper discusses the methods and results of stereotactic helium-ion radiosurgery of the pituitary gland at Lawrence Berkeley Laboratory. 11 refs

Clinical results of stereotactic hellium-ion radiosurgery of the pituitary gland at Lawrence Berkeley Laboratory

Energy Technology Data Exchange (ETDEWEB)

Levy, R.P.; Fabrikant, J.I.; Lyman, J.T.; Frankel, K.A.; Phillips, M.H.; Lawrence, J.H.; Tobias, C.A.

1989-12-01

The first therapeutic clinical trial using accelerated heavy-charged particles in humans was performed at Lawrence Berkeley Laboratory (LBL) for the treatment of various endocrine and metabolic disorders of the pituitary gland, and as suppressive therapy for adenohypophyseal hormone-responsive carcinomas and diabetic retinopathy. In acromegaly, Cushing's disease, Nelson's syndrome and prolactin-secreting tumors, the therapeutic goal in the 433 patients treated has been to destroy or inhibit the growth of the pituitary tumor and control hormonal hypersecretion, while preserving a functional rim of tissue with normal hormone-secreting capacity, and minimizing neurologic injury. An additional group of 34 patients was treated for nonsecreting chromophobe adenomas. This paper discusses the methods and results of stereotactic helium-ion radiosurgery of the pituitary gland at Lawrence Berkeley Laboratory. 11 refs.

Annual environmental monitoring report of the Lawrence Berkeley Laboratory

International Nuclear Information System (INIS)

Schleimer, G.E.

1989-06-01

The Environmental Monitoring Program of the Lawrence Berkeley Laboratory (LBL) is described. Data for 1988 are presented and general trends are discussed. In order to establish whether LBL research activities produced any impact on the population surrounding the laboratory, a program of environmental air and water sampling and continuous radiation monitoring was carried on throughout the year. For 1988, as in the previous several years, dose equivalents attributable to LBL radiological operations were a small fraction of both the relevant radiation protection guidelines (RPG) and of the natural radiation background. 16 refs., 7 figs., 21 tabs

Assembly Manual for the Berkeley Lab Cosmic Ray Detector

International Nuclear Information System (INIS)

Collier, Michael

2002-01-01

The Berkeley Lab Cosmic Ray Detector consists of 3 main components that must be prepared separately before they can be assembled. These components are the scintillator, circuit board, and casing. They are described in the main sections of this report, which may be completed in any order. Preparing the scintillator paddles involves several steps--cutting the scintillator material to the appropriate size and shape, preparing and attaching Lucite cookies (optional), polishing the edges, gluing the end to the photomultiplier tube (optional), and wrapping the scintillator. Since the detector has 2 paddles, each of the sections needs to be repeated for the other paddle

Annual environmental monitoring report of the Lawrence Berkeley Laboratory

Energy Technology Data Exchange (ETDEWEB)

Schleimer, G.E. (ed.)

1989-06-01

The Environmental Monitoring Program of the Lawrence Berkeley Laboratory (LBL) is described. Data for 1988 are presented and general trends are discussed. In order to establish whether LBL research activities produced any impact on the population surrounding the laboratory, a program of environmental air and water sampling and continuous radiation monitoring was carried on throughout the year. For 1988, as in the previous several years, dose equivalents attributable to LBL radiological operations were a small fraction of both the relevant radiation protection guidelines (RPG) and of the natural radiation background. 16 refs., 7 figs., 21 tabs.

Hill, Prof. Archibald Vivian

Indian Academy of Sciences (India)

Home; Fellowship. Fellow Profile. Elected: 1935 Honorary. Hill, Prof. Archibald Vivian Nobel Laureate (Medicine) - 1922. Date of birth: 26 September 1886. Date of death: 3 June 1977. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year ...

The montane forest associated amphibian species of the Taita Hills ...

African Journals Online (AJOL)

The montane forest associated amphibian species of the Taita Hills, Kenya. ... They are surrounded by the dry Tsavo plains. ... The biodiversity importance of the Taita Hills lies with the number of endemics per unit of area of remaining forest, ...

Tunnel magnetoresistance in asymmetric double-barrier magnetic tunnel junctions

International Nuclear Information System (INIS)

Useinov, N.Kh.; Petukhov, D.A.; Tagirov, L.R.

2015-01-01

The spin-polarized tunnel conductance and tunnel magnetoresistance (TMR) through a planar asymmetric double-barrier magnetic tunnel junction (DBMTJ) have been calculated using quasi-classical model. In DBMTJ nanostructure the magnetization of middle ferromagnetic metal layer can be aligned parallel or antiparallel with respect to the fixed magnetizations of the top and bottom ferromagnetic electrodes. The transmission coefficients of an electron to pass through the barriers have been calculated in terms of quantum mechanics. The dependencies of tunnel conductance and TMR on the applied voltage have been calculated in case of non-resonant transmission. Estimated in the framework of our model, the difference between the spin-channels conductances at low voltages was found relatively large. This gives rise to very high magnitude of TMR. - Highlights: • The spin-polarized conductance through the junction is calculated. • Dependencies of the tunnel conductance vs applied bias are shown. • Bias voltage dependence of tunnel magnetoresistance for the structure is shown

Environmental Justice Screening Method (EJSM) Score, San Joaquin Valley CA, 2013, Occidental College and UC Berkeley

Data.gov (United States)

U.S. Environmental Protection Agency — The Cumulative Impacts (CI) screening method is jointly being developed by Manuel Pastor, Jim Sadd (Occidental College), and Rachel Morello-Frosch (UC Berkeley) ....

The design and implementation of Berkeley Lab's linuxcheckpoint/restart

Energy Technology Data Exchange (ETDEWEB)

Duell, Jason

2005-04-30

This paper describes Berkeley Linux Checkpoint/Restart (BLCR), a linux kernel module that allows system-level checkpoints on a variety of Linux systems. BLCR can be used either as a stand alone system for checkpointing applications on a single machine, or as a component by a scheduling system or parallel communication library for checkpointing and restoring parallel jobs running on multiple machines. Integration with Message Passing Interface (MPI) and other parallel systems is described.

Are hills like white elephants?

Directory of Open Access Journals (Sweden)

Sunil Sharma

2016-11-01

Full Text Available 'Are Hills Like White Elephants?' is, of course, inspired by Hemingway; the tribute reflects on the abiding relevance of serious art in a changed world and extends the boundaries of his message to other human situations.

Late Devonian spermatophyte diversity and paleoecology at Red Hill, north-central Pennsylvania, USA

Energy Technology Data Exchange (ETDEWEB)

Cressler, Walter L. III. [Francis Harvey Green Library, 29 West Rosedale Avenue, West Chester University, West Chester, PA, 19383 (United States); Prestianni, Cyrille [Universite de Liege, Boulevard du Rectorat B18, Liege 4000 (Belgium); LePage, Ben A. [The Academy of Natural Sciences, 1900 Benjamin Franklin Parkway, Philadelphia, PA, 19103 and PECO Energy Company, 2301 Market Avenue, S9-1, Philadelphia, PA 19103 (United States)

2010-08-01

Early spermatophytes have been discovered at Red Hill, a Late Devonian (Famennian) fossil locality in north-central Pennsylvania, USA. The Red Hill locality contains an Archaeopteris-dominated flora within an outcrop of the Duncannon Member of the Catskill Formation. Palynological analyses of the plant fossil-bearing horizons within the Red Hill outcrop indicate deposition within the VCo palynozone. This is the earliest time horizon known to contain evidence for spermatophytes, and is contemporaneous with well-known spermatophyte-bearing deposits in West Virginia and Belgium. Some of the spermatophyte material from Red Hill compares well with Aglosperma sp., previously known as isolated ovules from the latest Devonian of South Wales and England, thus extending its geographic and stratigraphic range. Red Hill specimens of Aglosperma sp. occur both as isolated ovules and attached to dichotomously forking axes. Additional spermatophyte cupules discovered at Red Hill are morphologically similar to those of the previously described Late Devonian spermatophytes Elkinsia Rothwell, Scheckler, et Gillespie, Moresnetia Stockmans, and Xenotheca Arber et Goode. Some of the Red Hill cupule complexes are distinct from the aforementioned taxa in consisting of slender dichotomously forking axes terminating in paired cupules with highly fused and symmetric cupule quadrant lobes. The distinctive nature of these Red Hill specimens warrants the creation of Duodimidia pfefferkornii Cressler, Prestianni, et LePage gen. et sp. nov. Plant fossil remains with sphenopteroid foliage are also present at Red Hill, possibly attributable to the spermatophytes. Previous systematic sampling of the rich plant-fossil bearing layer at Red Hill and analysis of its floristic diversity and abundance as well as the presence and absence of charcoal suggests a pattern of floral turnover from a local-scale Rhacophyton-dominated community to spermatophyte colonization following disturbance by wildfires

Changes in prices, sales, consumer spending, and beverage consumption one year after a tax on sugar-sweetened beverages in Berkeley, California, US: A before-and-after study.

Science.gov (United States)

Silver, Lynn D; Ng, Shu Wen; Ryan-Ibarra, Suzanne; Taillie, Lindsey Smith; Induni, Marta; Miles, Donna R; Poti, Jennifer M; Popkin, Barry M

2017-04-01

Taxes on sugar-sweetened beverages (SSBs) meant to improve health and raise revenue are being adopted, yet evaluation is scarce. This study examines the association of the first penny per ounce SSB excise tax in the United States, in Berkeley, California, with beverage prices, sales, store revenue/consumer spending, and usual beverage intake. Methods included comparison of pre-taxation (before 1 January 2015) and first-year post-taxation (1 March 2015-29 February 2016) measures of (1) beverage prices at 26 Berkeley stores; (2) point-of-sale scanner data on 15.5 million checkouts for beverage prices, sales, and store revenue for two supermarket chains covering three Berkeley and six control non-Berkeley large supermarkets in adjacent cities; and (3) a representative telephone survey (17.4% cooperation rate) of 957 adult Berkeley residents. Key hypotheses were that (1) the tax would be passed through to the prices of taxed beverages among the chain stores in which Berkeley implemented the tax in 2015; (2) sales of taxed beverages would decline, and sales of untaxed beverages would rise, in Berkeley stores more than in comparison non-Berkeley stores; (3) consumer spending per transaction (checkout episode) would not increase in Berkeley stores; and (4) self-reported consumption of taxed beverages would decline. Main outcomes and measures included changes in inflation-adjusted prices (cents/ounce), beverage sales (ounces), consumers' spending measured as store revenue (inflation-adjusted dollars per transaction) in two large chains, and usual beverage intake (grams/day and kilocalories/day). Tax pass-through (changes in the price after imposition of the tax) for SSBs varied in degree and timing by store type and beverage type. Pass-through was complete in large chain supermarkets (+1.07¢/oz, p = 0.001) and small chain supermarkets and chain gas stations (1.31¢/oz, p = 0.004), partial in pharmacies (+0.45¢/oz, p = 0.03), and negative in independent corner stores and

The principle of phase stability and the accelerator program at Berkeley, 1945--1954

International Nuclear Information System (INIS)

Lofgren, E.J.

1994-07-01

The discovery of the Principle of Phase Stability by Vladimir Veksler and Edwin McMillian and the end of the war released a surge of accelerator activity at the Lawrence Berkeley Laboratory (then The University of California Radiation Laboratory). Six accelerators incorporating the Principle of Phase Stability were built in the period 1945--1954

Preparations for decommissioning the TRIGA Mark III Berkeley Research Reactor

International Nuclear Information System (INIS)

Denton, Michael M.; Lim, Tek. H.

1988-01-01

On December 20, 1986 the chancellor of UC Berkeley announced his decision to decommission the 20 year old Berkeley Research Reactor citing as principal reasons a decline in use and a need to erect a new computer science building over the reactor's site. In order to meet the University's construction timetable for the new building, the reactor staff together with other units of the campus administration have initiated a program to remove the reactor structure and clear the room for unlicensed use as expediently as possible. Due to the sequence of events which must occur in a limited amount of time, the University adopted a policy to contract out as much of the work as possible, including generation of the defueling and decommissioning plans.The first physical step in the decommissioning project is the removal of the irradiated fuel. This task is largely contracted out to a commercial firm with experience in the transport of radioactive materials and reactor fuel. As suggested by the NRC, the reactor will be defueled under the current operating license. This requires that all fuel must be off-site before the DP can be approved. Therefore any delay in defueling in-turn delays the decommissioning. The NRC has given no commitment or date for completion of their review. Informal discussion with NRC project managers and the experience from other facilities indicate that the review process will take between six and nine months

Magnetic tunnel junctions with monolayer hexagonal boron nitride tunnel barriers

Energy Technology Data Exchange (ETDEWEB)

Piquemal-Banci, M.; Galceran, R.; Bouzehouane, K.; Anane, A.; Petroff, F.; Fert, A.; Dlubak, B.; Seneor, P. [Unité Mixte de Physique, CNRS, Thales, Univ. Paris-Sud, Université Paris-Saclay, Palaiseau 91767 (France); Caneva, S.; Martin, M.-B.; Weatherup, R. S.; Kidambi, P. R.; Robertson, J.; Hofmann, S. [Department of Engineering, University of Cambridge, Cambridge CB21PZ (United Kingdom); Xavier, S. [Thales Research and Technology, 1 avenue Augustin Fresnel, Palaiseau 91767 (France)

2016-03-07

We report on the integration of atomically thin 2D insulating hexagonal boron nitride (h-BN) tunnel barriers into Co/h-BN/Fe magnetic tunnel junctions (MTJs). The h-BN monolayer is directly grown by chemical vapor deposition on Fe. The Conductive Tip Atomic Force Microscopy (CT-AFM) measurements reveal the homogeneity of the tunnel behavior of our h-BN layers. As expected for tunneling, the resistance depends exponentially on the number of h-BN layers. The h-BN monolayer properties are also characterized through integration into complete MTJ devices. A Tunnel Magnetoresistance of up to 6% is observed for a MTJ based on a single atomically thin h-BN layer.

Variability in ACL tunnel placement: observational clinical study of surgeon ACL tunnel variability.

Science.gov (United States)

Wolf, Brian R; Ramme, Austin J; Wright, Rick W; Brophy, Robert H; McCarty, Eric C; Vidal, Armando R; Parker, Richard D; Andrish, Jack T; Amendola, Annunziato

2013-06-01

Multicenter and multisurgeon cohort studies on anterior cruciate ligament (ACL) reconstruction are becoming more common. Minimal information exists on intersurgeon and intrasurgeon variability in ACL tunnel placement. Purpose/ The purpose of this study was to analyze intersurgeon and intrasurgeon variability in ACL tunnel placement in a series of The Multicenter Orthopaedic Outcomes Network (MOON) ACL reconstruction patients and in a clinical cohort of ACL reconstruction patients. The hypothesis was that there would be minimal variability between surgeons in ACL tunnel placement. Cross-sectional study; Level of evidence, 3. Seventy-eight patients who underwent ACL reconstruction by 8 surgeons had postoperative imaging with computed tomography, and ACL tunnel location and angulation were analyzed using 3-dimensional surface processing and measurement. Intersurgeon and intrasurgeon variability in ACL tunnel placement was analyzed. For intersurgeon variability, the range in mean ACL femoral tunnel depth between surgeons was 22%. For femoral tunnel height, there was a 19% range. Tibial tunnel location from anterior to posterior on the plateau had a 16% range in mean results. There was only a small range of 4% for mean tibial tunnel location from the medial to lateral dimension. For intrasurgeon variability, femoral tunnel depth demonstrated the largest ranges, and tibial tunnel location from medial to lateral on the plateau demonstrated the least variability. Overall, surgeons were relatively consistent within their own cases. Using applied measurement criteria, 85% of femoral tunnels and 90% of tibial tunnels fell within applied literature-based guidelines. Ninety-one percent of the axes of the femoral tunnels fell within the boundaries of the femoral footprint. The data demonstrate that surgeons performing ACL reconstructions are relatively consistent between each other. There is, however, variability of average tunnel placement up to 22% of mean condylar depth

Interaction between groundwater and TBM (Tunnel Boring Machine) excavated tunnels

OpenAIRE

Font Capó, Jordi

2012-01-01

A number of problems, e.g. sudden inflows are encountered during tunneling under the piezometric level, especially when the excavation crosses high transmissivity areas. These inflows may drag materials when the tunnel crosses low competent layers, resulting in subsidence, chimney formation and collapses. Moreover, inflows can lead to a decrease in head level because of aquifer drainage. Tunnels can be drilled by a tunnel boring machine (TBM) to minimize inflows and groundwater impacts, restr...

The origin of Mauna Loa's Nīnole Hills: Evidence of rift zone reorganization

Science.gov (United States)

Zurek, Jeffrey; Williams-Jones, Glyn; Trusdell, Frank A.; Martin, Simon

2015-01-01

In order to identify the origin of Mauna Loa volcano's Nīnole Hills, Bouguer gravity was used to delineate density contrasts within the edifice. Our survey identified two residual anomalies beneath the Southwest Rift Zone (SWRZ) and the Nīnole Hills. The Nīnole Hills anomaly is elongated, striking northeast, and in inversions both anomalies merge at approximately −7 km above sea level. The positive anomaly, modeled as a rock volume of ~1200 km3 beneath the Nīnole Hills, is associated with old eruptive vents. Based on the geologic and geophysical data, we propose that the gravity anomaly under the Nīnole Hills records an early SWRZ orientation, now abandoned due to geologically rapid rift-zone reorganization. Catastrophic submarine landslides from Mauna Loa's western flank are the most likely cause for the concurrent abandonment of the Nīnole Hills section of the SWRZ. Rift zone reorganization induced by mass wasting is likely more common than currently recognized.

Wine Industry Competitiveness: A survey of the Shawnee Hills American Viticultural Area

Directory of Open Access Journals (Sweden)

C. Matthew Rendleman

2016-06-01

Shawnee Hill׳s AVA winery owner/operators regard increases in regional tourism, growth in the US wine market continuous innovation, unique services and processes, and flow of information from customers to have the most enhancing effects on their businesses, and that confidence/trust in Illinois state political systems, tax systems, and administrative/bureaucratic regulations were the most constraining factors. Furthermore the Shawnee Hills AVA has growing competition, yet consists of innovative winery owners. It may currently lack external financial support, but with a community focus on product differentiation, the Shawnee Hills AVA has a chance, owners believe, to capture a portion of the growing market for regional products.

Theory of synergistic effects: Hill-type response surfaces as 'null-interaction' models for mixtures.

Science.gov (United States)

Schindler, Michael

2017-08-02

The classification of effects caused by mixtures of agents as synergistic, antagonistic or additive depends critically on the reference model of 'null interaction'. Two main approaches are currently in use, the Additive Dose (ADM) or concentration addition (CA) and the Multiplicative Survival (MSM) or independent action (IA) models. We compare several response surface models to a newly developed Hill response surface, obtained by solving a logistic partial differential equation (PDE). Assuming that a mixture of chemicals with individual Hill-type dose-response curves can be described by an n-dimensional logistic function, Hill's differential equation for pure agents is replaced by a PDE for mixtures whose solution provides Hill surfaces as 'null-interaction' models and relies neither on Bliss independence or Loewe additivity nor uses Chou's unified general theory. An n-dimensional logistic PDE decribing the Hill-type response of n-component mixtures is solved. Appropriate boundary conditions ensure the correct asymptotic behaviour. Mathematica 11 (Wolfram, Mathematica Version 11.0, 2016) is used for the mathematics and graphics presented in this article. The Hill response surface ansatz can be applied to mixtures of compounds with arbitrary Hill parameters. Restrictions which are required when deriving analytical expressions for response surfaces from other principles, are unnecessary. Many approaches based on Loewe additivity turn out be special cases of the Hill approach whose increased flexibility permits a better description of 'null-effect' responses. Missing sham-compliance of Bliss IA, known as Colby's model in agrochemistry, leads to incompatibility with the Hill surface ansatz. Examples of binary and ternary mixtures illustrate the differences between the approaches. For Hill-slopes close to one and doses below the half-maximum effect doses MSM (Colby, Bliss, Finney, Abbott) predicts synergistic effects where the Hill model indicates 'null

Young Cluster Berkeley 59: Properties, Evolution, and Star Formation

Science.gov (United States)

Panwar, Neelam; Pandey, A. K.; Samal, Manash R.; Battinelli, Paolo; Ogura, K.; Ojha, D. K.; Chen, W. P.; Singh, H. P.

2018-01-01

Berkeley 59 is a nearby (∼1 kpc) young cluster associated with the Sh2-171 H II region. We present deep optical observations of the central ∼2.5 × 2.5 pc2 area of the cluster, obtained with the 3.58 m Telescopio Nazionale Galileo. The V/(V–I) color–magnitude diagram manifests a clear pre-main-sequence (PMS) population down to ∼0.2 M ⊙. Using the near-infrared and optical colors of the low-mass PMS members, we derive a global extinction of A V = 4 mag and a mean age of ∼1.8 Myr, respectively, for the cluster. We constructed the initial mass function and found that its global slopes in the mass ranges of 0.2–28 M ⊙ and 0.2–1.5 M ⊙ are ‑1.33 and ‑1.23, respectively, in good agreement with the Salpeter value in the solar neighborhood. We looked for the radial variation of the mass function and found that the slope is flatter in the inner region than in the outer region, indicating mass segregation. The dynamical status of the cluster suggests that the mass segregation is likely primordial. The age distribution of the PMS sources reveals that the younger sources appear to concentrate close to the inner region compared to the outer region of the cluster, a phenomenon possibly linked to the time evolution of star-forming clouds. Within the observed area, we derive a total mass of ∼103 M ⊙ for the cluster. Comparing the properties of Berkeley 59 with other young clusters, we suggest it resembles more closely the Trapezium cluster.

Diversity and biogeography of land snails (Mollusca, Gastropoda) in the limestone hills of Perak, Peninsular Malaysia

Science.gov (United States)

Foon, Junn Kitt; Clements, Gopalasamy Reuben; Liew, Thor-Seng

2017-01-01

Abstract Limestone hills are now gaining global conservation attention as hotspots for short-range endemic species. Levels of land snail endemism can be high at limestone hills, especially at hill clusters that are geographically isolated. In the State of Perak, Peninsular Malaysia, limestone hills have been opportunistically surveyed for land snails in the past, but the majority have yet to be surveyed. To address this knowledge gap, we systematically surveyed the terrestrial malacofauna of 12 limestone hills that, based on our opinion, are a representation of the limestone land snail assemblages within the State. Our inventory yielded high sampling completeness (>85%). We found 122 species of land snails, of which 34 species were unique to one of the surveyed hills. We identified 30 species that are potentially new to science. The number of land snail species recorded at each hill ranged between 39 and 63 species. Four of the sampled limestone hills namely, Prk 01 G. Tempurung, Prk 55 G. Pondok, Prk 47 Kanthan, and Prk 64 Bt Kepala Gajah, have high levels of species richness and unique species, representing 91% of the total species recorded in this study. We identified two clusters of limestone hills in central Perak with distinct differences in land snail species composition – a northern hill cluster on elevated granite bedrock and southern hill cluster in a low-lying valley surrounded by alluvial soils. As limestone hills continue to be quarried to meet the cement demand, the four identified limestone hills, along with other hills from the two clusters, warrant urgent conservation attention in order to maintain high species diversity within Perak’s terrestrial malacofauna. PMID:28769723

Berkeley Lab's Saul Perlmutter wins E.O. Lawrence Award; scientist's work on supernovae reveals accelerating Universe

CERN Multimedia

2002-01-01

Saul Perlmutter, from Lawrence Berkeley National Laboratory Physics Division and leader of the Supernova Cosmology Project based there, has won the DOE's 2002 E.O. Lawrence Award in the physics category (2 pages).

Dilepton (e+e-) production recent pp and pd studies with DLS at Berkeley

International Nuclear Information System (INIS)

Schroeder, L.S.

1991-09-01

The use of dileptons as probes of hot, dense hadronic matter is described. Preliminary results on dileptons produced in p-p and p-d interactions at the Bevalac are presented along with potential ramifications for existing model calculations of dileptons at these energies. Future directions of the dilepton program at Berkeley are outlined. 14 refs., 3 figs

Frequency driven inversion of tunnel magnetoimpedance and observation of positive tunnel magnetocapacitance in magnetic tunnel junctions

International Nuclear Information System (INIS)

Parui, Subir; Ribeiro, Mário; Atxabal, Ainhoa; Llopis, Roger; Bedoya-Pinto, Amilcar; Sun, Xiangnan; Casanova, Fèlix; Hueso, Luis E.

2016-01-01

The relevance for modern computation of non-volatile high-frequency memories makes ac-transport measurements of magnetic tunnel junctions (MTJs) crucial for exploring this regime. Here, we demonstrate a frequency-mediated effect in which the tunnel magnetoimpedance reverses its sign in a classical Co/Al 2 O 3 /NiFe MTJ, whereas we only observe a gradual decrease in the tunnel magnetophase. Such effects are explained by the capacitive coupling of a parallel resistor and capacitor in the equivalent circuit model of the MTJ. Furthermore, we report a positive tunnel magnetocapacitance effect, suggesting the presence of a spin-capacitance at the two ferromagnet/tunnel-barrier interfaces. Our results are important for understanding spin transport phenomena at the high frequency regime in which the spin-polarized charge accumulation due to spin-dependent penetration depth at the two interfaces plays a crucial role.

Frequency driven inversion of tunnel magnetoimpedance and observation of positive tunnel magnetocapacitance in magnetic tunnel junctions

Energy Technology Data Exchange (ETDEWEB)

Parui, Subir, E-mail: s.parui@nanogune.eu, E-mail: l.hueso@nanogune.eu; Ribeiro, Mário; Atxabal, Ainhoa; Llopis, Roger [CIC nanoGUNE, 20018 Donostia-San Sebastian (Spain); Bedoya-Pinto, Amilcar [CIC nanoGUNE, 20018 Donostia-San Sebastian (Spain); Max Planck Institute of Microstructure Physics, D-06120 Halle (Germany); Sun, Xiangnan [CIC nanoGUNE, 20018 Donostia-San Sebastian (Spain); National Center for Nanoscience and Technology, 100190 Beijing (China); Casanova, Fèlix; Hueso, Luis E., E-mail: s.parui@nanogune.eu, E-mail: l.hueso@nanogune.eu [CIC nanoGUNE, 20018 Donostia-San Sebastian (Spain); IKERBASQUE, Basque Foundation for Science, 48011 Bilbao (Spain)

2016-08-01

The relevance for modern computation of non-volatile high-frequency memories makes ac-transport measurements of magnetic tunnel junctions (MTJs) crucial for exploring this regime. Here, we demonstrate a frequency-mediated effect in which the tunnel magnetoimpedance reverses its sign in a classical Co/Al{sub 2}O{sub 3}/NiFe MTJ, whereas we only observe a gradual decrease in the tunnel magnetophase. Such effects are explained by the capacitive coupling of a parallel resistor and capacitor in the equivalent circuit model of the MTJ. Furthermore, we report a positive tunnel magnetocapacitance effect, suggesting the presence of a spin-capacitance at the two ferromagnet/tunnel-barrier interfaces. Our results are important for understanding spin transport phenomena at the high frequency regime in which the spin-polarized charge accumulation due to spin-dependent penetration depth at the two interfaces plays a crucial role.

Carpal Tunnel Syndrome

Science.gov (United States)

... a passing cramp? It could be carpal tunnel syndrome. The carpal tunnel is a narrow passageway of ... three times more likely to have carpal tunnel syndrome than men. Early diagnosis and treatment are important ...

Theory of superconducting tunneling without the tunneling Hamiltonian

International Nuclear Information System (INIS)

Arnold, G.B.

1987-01-01

When a tunneling barrier is nearly transparent, the standard tunneling (or transfer) Hamiltonian approximation fails. The author describes the theory which is necessary for calculating the tunneling current in these cases, and illustrate it by comparing theory and experiment on superconductor/insulator/superconductor (SIS) junctions have ultra-thin tunnel barriers. This theory accurately explains the subgap structure which appears in the dynamical resistance of such SIS junctions, including many observed details which no previous theory has reproduced. The expression for the current through an SIS junction with an ultrathin barrier is given by I(t) = Re{Sigma/sub n/ J/sub n/ (omega/sub o/)e/sup in omega/o/sup t/} where omega/sub o/ = 2eV/h is the Josephson frequency, V is the bias voltage, and the J/sub n/ are voltage dependent coefficients, one for each positive or negative integer, n, and n=0. The relative sign of the terms involving cos(n omega/sub o/t) and sin(n omega/sub o/t) agrees with experiment, in contrast to previous theories of Josephson tunneling

Catalog of Research Abstracts, 1993: Partnership opportunities at Lawrence Berkeley Laboratory

Energy Technology Data Exchange (ETDEWEB)

1993-09-01

The 1993 edition of Lawrence Berkeley Laboratory`s Catalog of Research Abstracts is a comprehensive listing of ongoing research projects in LBL`s ten research divisions. Lawrence Berkeley Laboratory (LBL) is a major multi-program national laboratory managed by the University of California for the US Department of Energy (DOE). LBL has more than 3000 employees, including over 1000 scientists and engineers. With an annual budget of approximately $250 million, LBL conducts a wide range of research activities, many that address the long-term needs of American industry and have the potential for a positive impact on US competitiveness. LBL actively seeks to share its expertise with the private sector to increase US competitiveness in world markets. LBL has transferable expertise in conservation and renewable energy, environmental remediation, materials sciences, computing sciences, and biotechnology, which includes fundamental genetic research and nuclear medicine. This catalog gives an excellent overview of LBL`s expertise, and is a good resource for those seeking partnerships with national laboratories. Such partnerships allow private enterprise access to the exceptional scientific and engineering capabilities of the federal laboratory systems. Such arrangements also leverage the research and development resources of the private partner. Most importantly, they are a means of accessing the cutting-edge technologies and innovations being discovered every day in our federal laboratories.

Fertility in Hill Korwas -- a primitive tribe of Madhya Pradesh.

Science.gov (United States)

Pandey, G D; Tiwary, R S

1996-12-01

This study examines fertility behavior among 604 eligible couples in Hill Korwa tribes in Madhya Pradesh state, India. Low fertility patterns are compared to those of neighboring Gonds and nontribals from rural Jabalpur. The Hill Korwa are a subtribe of the Korwa, who remained in the hills and dense forests. Over 60% live in three tehsils of Surguja district, including Ambikapur tehsil where the study was conducted. Data were obtained in March 1991. Eligible couples were those where both partners live together and the noncontracepting wife is under age 50 and nonmenopausal. Only 3% were literate. Female marriage age was about 15 years. The median age was 23.8 years. 92% lived below the poverty line. The average number of children ever born (CEB) per couple was 1.9, compared to 2.5 for the Gond and 2.9 for nontribal couples. The CEB in a reproductive lifetime was 2.9, compared to 5.3 for Gond women and 5.9 for nontribal women. Fecundity among Hill Korwa women was 66% lower at younger ages (16-17 years and 17-18 years), and the differences increased with an increase in age at marriage. Hill Korwas had a low female age at marriage, low literacy, low percentages engaged in agriculture, and higher percentages living above the poverty line.

Midwest nukes tumble, rock industry: Byron, Marble Hill, Zimmer

International Nuclear Information System (INIS)

Nogee, A.

1984-01-01

The nuclear industry is suffering from a lack of investor confidence because of cancelled projects and the unprecedented rejection of an operating license for Commonwealth Edison's Byron plant on grounds that the utility failed to meet quality assurance responsibilities. When plans to complete the Zimmer and Marble Hill nuclear plants were abandoned, Bechtel came forward with a financing plan that, while rejected for Zimmer and Marble Hill, could lead to future bailouts. Both Zimmer and Marble Hill plants could be partially converted to coal. The loss of investor confidence in nuclear plants is largely due to political pressures brought on by a combination of citizen intervenors, whistle blowers on construction sites and disagreements between participating utilities. A rise in stock prices followed the cancellation announcements and the lowered investment security ratings

Environmental assessment for the proposed construction and operation of a Genome Sequencing Facility in Building 64 at Lawrence Berkeley Laboratory, Berkeley, California

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-04-01

This document is an Environmental Assessment (EA) for a proposed project to modify 14,900 square feet of an existing building (Building 64) at Lawrence Berkeley Laboratory (LBL) to operate as a Genome Sequencing Facility. This EA addresses the potential environmental impacts from the proposed modifications to Building 64 and operation of the Genome Sequencing Facility. The proposed action is to modify Building 64 to provide space and equipment allowing LBL to demonstrate that the Directed DNA Sequencing Strategy can be scaled up from the current level of 750,000 base pairs per year to a facility that produces over 6,000,000 base pairs per year, while still retaining its efficiency.

Progress report on the Berkeley/Anglo-Australian Observatory high-redshift supernova search

International Nuclear Information System (INIS)

Goldhaber, G.; Perlmutter, S.; Pennypacker, C.; Marvin, H.; Muller, R.A.; Couch, W.; Boyle, B.

1990-11-01

There are two main efforts related to supernovae in progress at Berkeley. The first is an automated supernova search for nearby supernovae, which was already discussed by Carl Pennypacker at this conference. The second is a search for distant supernovae, in the z = 0.3 to 0.5 region, aimed at measuring Ω. It is the latter that I want to discuss in this paper. 3 refs., 18 figs

Construction and operation of replacement hazardous waste handling facility at Lawrence Berkeley Laboratory. Environmental Assessment

Energy Technology Data Exchange (ETDEWEB)

1992-09-01

The US Department of Energy (DOE) has prepared an environmental assessment (EA), DOE/EA-0423, for the construction and operation of a replacement hazardous waste handling facility (HWHF) and decontamination of the existing HWHF at Lawrence Berkeley Laboratory (LBL), Berkeley, California. The proposed facility would replace several older buildings and cargo containers currently being used for waste handling activities and consolidate the LBL`s existing waste handling activities in one location. The nature of the waste handling activities and the waste volume and characteristics would not change as a result of construction of the new facility. Based on the analysis in the EA, DOE has determined that the proposed action would not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969, 42 USC. 4321 et seq. Therefore, an environmental impact statement is not required.

Tunneling works. Tunnel koji

Energy Technology Data Exchange (ETDEWEB)

Higo, M [Hazam Gumi, Ltd., Tokyo (Japan)

1991-10-25

A mountain tunneling method for rock-beds used to be applied mainly to construction works in the mountains under few restrictions by environmental problems. However, construction works near residential sreas have been increasing. There are such enviromental problems due to tunneling works as vibration, noise, lowering of ground-water level, and influences on other structures. This report mainly describes the measurement examples of vibration and noise accompanied with blasting and the effects of the measures to lessen such influences. When the tunneling works for the railroad was carried out on the natural ground mainly composed of basalt, vibration of the test blasting was measured at three stations with piezoelectric accelerometers. Then, ordinary blasting, mutistage blasting, and ABM blasting methods were used properly besed on the above results, and only a few complaints were made. In the different works, normal noise and low-frequency sound were mesured at 22 stations around the pit mouth. As countermeasures for noise, sound-proof sheets, walls, and single and double doors were installed and foundto be effective. 1 ref., 6 figs., 1 tab.

Lawrence Berkeley laboratory neutral-beam engineering test facility power-supply system

International Nuclear Information System (INIS)

Lutz, I.C.; Arthur, C.A.; deVries, G.J.; Owren, H.M.

1981-10-01

The Lawrence Berkeley Laboratory is upgrading the neutral beam source test facility (NBSTF) into a neutral beam engineering test facility (NBETF) with increased capabilities for the development of neutral beam systems. The NBETF will have an accel power supply capable of 170 kV, 70 A, 30 sec pulse length, 10% duty cycle; and the auxiliary power supplies required for the sources. This paper describes the major components, their ratings and capabilities, and the flexibility designed to accomodate the needs of source development

Tunneling junction as an open system. Normal tunneling

International Nuclear Information System (INIS)

Ono, Y.

1978-01-01

The method of the tunneling Hamiltonian is reformulated in the case of normal tunneling by introducing two independent particle baths. Due to the baths, it becomes possible to realize a final stationary state where the electron numbers of the two electrodes in the tunneling system are maintained constant and where there exists a stationary current. The effect of the bath-system couplings on the current-voltage characteristics of the junction is discussed in relation to the usual expression of the current as a function of voltage. (Auth.)

Microhabitats of Merriam's turkeys in the Black Hills, South Dakota

Science.gov (United States)

Mark A. Rumble; Stanley H. Anderson

1996-01-01

Merriam’s Turkeys (Meleagris gallopavo merriami) are associated with ponderosa pine (Pinus ponderosa) forests in the western United States, but are not native to the ponderosa pine forest of the Black Hills, South Dakota. The Black Hills population was established by transplanting birds from New Mexico and Colorado between 1948 and...

Fermilab and Berkeley Lab Collaborate with Meyer Tool on Key Component for European Particle Accelerator

CERN Multimedia

2004-01-01

Officials of the U.S. Department of Energy's Fermi National Accelerator Laboratory and Lawrence Berkeley National Laboratory announced yesterday the completion of a key component of the U.S. contribution to the Large Hadron Collider, a particle accelerator under construction at CERN, in Geneva, Switzerland

State of conservation of Santa Martha's hills, Colombia

International Nuclear Information System (INIS)

Lopez Salgado, Hector Jaime; Carbono Delahoz, Eduino

2006-01-01

The urban growth of Santa Marta and the occupation without planning of their surrounding hills, affect their natural conditions. The hills are part of the scenic beauty of the city and its conservation is indispensable to maintain the standard of life in her the vegetal cover corresponds to forests and scrubs of isomegathermic floor with xeromorphic characters, due to the low pluvial precipitation, this landscape characterizes the Colombian Caribbean coast in a narrow strip that extends from the south of the Guajira to the gulf of Morrosquillo. At the present time, only they are left surpluses in natural state, due to the floristic simplification of the vegetation, the introduction of invading species and modification of the landscape. The responsibility of the suitable handling of the urban space is imperative for the official, private sector and citizen institutions. The objective is to make an evaluation of the environmental conditions of hills of the city, in order to obtain basic elements, for the design of appropriate strategies of handling and its conservation. By means of the use of the GIS, with verification and aerial photo interpretation of field a multi-temporary study (1955-1993-2003) of the vegetal cover of the hills was elaborated that allowed to establish the happened changes. The execution of inventors allowed knowing the wealth and the structure floristic the vegetal cover of the area. The work was executed between May of the 2004 and May of the 2005

Tunneling time, exit time and exit momentum in strong field tunnel ionization

International Nuclear Information System (INIS)

Teeny, Nicolas

2016-01-01

Tunnel ionization belongs to the fundamental processes of atomic physics. It is still an open question when does the electron tunnel ionize and how long is the duration of tunneling. In this work we solve the time-dependent Schroedinger equation in one and two dimensions and use ab initio quantum calculations in order to answer these questions. Additionally, we determine the exit momentum of the tunnel ionized electron from first principles. We find out results that are different from the assumptions of the commonly employed two-step model, which assumes that the electron ionizes at the instant of electric field maximum with a zero momentum. After determining the quantum final momentum distribution of tunnel ionized electrons we show that the two-step model fails to predict the correct final momentum. Accordingly we suggest how to correct the two-step model. Furthermore, we determine the instant at which tunnel ionization starts, which turns out to be different from the instant usually assumed. From determining the instant at which it is most probable for the electron to enter the tunneling barrier and the instant at which it exits we determine the most probable time spent under the barrier. Moreover, we apply a quantum clock approach in order to determine the duration of tunnel ionization. From the quantum clock we determine an average tunneling time which is different in magnitude and origin with respect to the most probable tunneling time. By defining a probability distribution of tunneling times using virtual detectors we relate both methods and explain the apparent discrepancy. The results found have in general an effect on the interpretation of experiments that measure the spectra of tunnel ionized electrons, and specifically on the calibration of the so called attoclock experiments, because models with imprecise assumptions are usually employed in order to interpret experimental results.

Tunneling time, exit time and exit momentum in strong field tunnel ionization

Energy Technology Data Exchange (ETDEWEB)

Teeny, Nicolas

2016-10-18

Tunnel ionization belongs to the fundamental processes of atomic physics. It is still an open question when does the electron tunnel ionize and how long is the duration of tunneling. In this work we solve the time-dependent Schroedinger equation in one and two dimensions and use ab initio quantum calculations in order to answer these questions. Additionally, we determine the exit momentum of the tunnel ionized electron from first principles. We find out results that are different from the assumptions of the commonly employed two-step model, which assumes that the electron ionizes at the instant of electric field maximum with a zero momentum. After determining the quantum final momentum distribution of tunnel ionized electrons we show that the two-step model fails to predict the correct final momentum. Accordingly we suggest how to correct the two-step model. Furthermore, we determine the instant at which tunnel ionization starts, which turns out to be different from the instant usually assumed. From determining the instant at which it is most probable for the electron to enter the tunneling barrier and the instant at which it exits we determine the most probable time spent under the barrier. Moreover, we apply a quantum clock approach in order to determine the duration of tunnel ionization. From the quantum clock we determine an average tunneling time which is different in magnitude and origin with respect to the most probable tunneling time. By defining a probability distribution of tunneling times using virtual detectors we relate both methods and explain the apparent discrepancy. The results found have in general an effect on the interpretation of experiments that measure the spectra of tunnel ionized electrons, and specifically on the calibration of the so called attoclock experiments, because models with imprecise assumptions are usually employed in order to interpret experimental results.

Quantum theory of tunneling

CERN Document Server

Razavy, Mohsen

2014-01-01

In this revised and expanded edition, in addition to a comprehensible introduction to the theoretical foundations of quantum tunneling based on different methods of formulating and solving tunneling problems, different semiclassical approximations for multidimensional systems are presented. Particular attention is given to the tunneling of composite systems, with examples taken from molecular tunneling and also from nuclear reactions. The interesting and puzzling features of tunneling times are given extensive coverage, and the possibility of measurement of these times with quantum clocks are critically examined. In addition by considering the analogy between evanescent waves in waveguides and in quantum tunneling, the times related to electromagnetic wave propagation have been used to explain certain aspects of quantum tunneling times. These topics are treated in both non-relativistic as well as relativistic regimes. Finally, a large number of examples of tunneling in atomic, molecular, condensed matter and ...

Mass, charge, and energy separation by selective acceleration with a traveling potential hill

Science.gov (United States)

Tung, L. Schwager; Barr, W. L.; Lowder, R. S.; Post, R. F.

1996-10-01

A traveling electric potential hill has been used to generate an ion beam with an energy distribution that is mass dependent from a monoenergetic ion beam of mixed masses. This effect can be utilized as a novel method for mass separation applied to identification or enrichment of ions (e.g., of elements, isotopes, or molecules). This theory for mass-selective acceleration is presented here and is shown to be confirmed by experiment and by a time-dependent particle-in-cell computer simulation. Results show that monoenergetic ions with the particular mass of choice are accelerated by controlling the hill potential and the hill velocity. The hill velocity is typically 20%-30% faster than the ions to be accelerated. The ability of the hill to pickup a particular mass uses the fact that small kinetic energy differences in the lab frame appear much larger in the moving hill frame. Ions will gain energy from the approaching hill if their relative energy in the moving hill frame is less than the peak potential of the hill. The final energy of these accelerated ions can be several times the source energy, which facilitates energy filtering for mass purification or identification. If the hill potential is chosen to accelerate multiple masses, the heaviest mass will have the greatest final energy. Hence, choosing the appropriate hill potential and collector retarding voltage will isolate ions with the lightest, heaviest, or intermediate mass. In the experimental device, called a Solitron, purified 20Ne and 22Ne are extracted from a ribbon beam of neon that is originally composed of 20Ne:22Ne in the natural ratio of 91:9. The isotopic content of the processed beam is determined by measuring the energy distribution of the detected current. These results agree with the theory. In addition to mass selectivity, our theory can also be applied to the filtration of an ion beam according to charge state or energy. Because of this variety of properties, the Solitron is envisioned to

The effect of a combined glenoid and Hill-Sachs defect on glenohumeral stability: a biomechanical cadaveric study using 3-dimensional modeling of 142 patients.

Science.gov (United States)

Arciero, Robert A; Parrino, Anthony; Bernhardson, Andrew S; Diaz-Doran, Vilmaris; Obopilwe, Elifho; Cote, Mark P; Golijanin, Petr; Mazzocca, Augustus D; Provencher, Matthew T

2015-06-01

Bone loss in anterior glenohumeral instability occurs on both the glenoid and the humerus; however, existing biomechanical studies have evaluated glenoid and humeral head defects in isolation. Thus, little is known about the combined effect of these bony lesions in a clinically relevant model on glenohumeral stability. The purpose of this study was to determine the biomechanical efficacy of a Bankart repair in the setting of bipolar (glenoid and humeral head) bone defects determined via computer-generated 3-dimensional (3D) modeling of 142 patients with recurrent anterior shoulder instability. The null hypothesis was that adding a bipolar bone defect will have no effect on glenohumeral stability after soft tissue Bankart repair. Controlled laboratory study. A total of 142 consecutive patients with recurrent anterior instability were analyzed with 3D computed tomography scans. Two Hill-Sachs lesions were selected on the basis of volumetric size representing the 25th percentile (0.87 cm(3); small) and 50th percentile (1.47 cm(3); medium) and printed in plastic resin with a 3D printer. A total of 21 cadaveric shoulders were evaluated on a custom shoulder-testing device permitting 6 degrees of freedom, and the force required to translate the humeral head anteriorly 10 mm at a rate of 2.0 mm/s with a compressive load of 50 N was determined at 60° of glenohumeral abduction and 60° of external rotation. All Bankart lesions were made sharply from the 2- to 6-o'clock positions for a right shoulder. Subsequent Bankart repair with transosseous tunnels using high-strength suture was performed. Hill-Sachs lesions were made in the cadaver utilizing a plastic mold from the exact replica off the 3D printer. Testing was conducted in the following sequence for each specimen: (1) intact, (2) posterior capsulotomy, (3) Bankart lesion, (4) Bankart repair, (5) Bankart lesion with 2-mm glenoid defect, (6) Bankart repair, (7) Bankart lesion with 2-mm glenoid defect and Hill-Sachs lesion

Installation and experimental uses of RTNS-I at the University of California, Berkeley

International Nuclear Information System (INIS)

Belian, A.P.; Morse, E.C.; Tobin, M.

1996-01-01

The National Ignition Facility (NIF) features optical components with line-of-sight access to the 14 MeV neutrons generated by fusion reactions in the target. Two of these components are a final focusing lens, made of fused silica, and a frequency conversion crystal comprised of two potassium dihydrogen phosphate (KDP) crystals. The Rotating Target Neutron Source (RTNS-I), which was previously operated at Lawrence Livermore National Laboratory (LLNL), has now been re-installed at UC Berkeley and is being used for the studies of neutron irradiation of fused silica and KDP. The machine has been installed so as to re-utilize the concrete structure that once housed the Berkeley Research Reactor, now decommissioned. The RTNS uses a 2 - 5 mA beam of deuterons impinging upon a spinning internally cooled tritiated copper target with a 110 Ci tritium inventory. Maximum beam energy is 399 KeV. The 14 MeV neutron production rate is 1.0x10 12 n/sec. Some new features of the machine include fiber-optic coupled microprocessor control of accelerator parameters, a cryogenic tritium collection system, and a scrubber system for exhaust tritium management. 15 refs., 4 figs

Control system for the 2nd generation Berkeley automounters (BAM2) at GM/CA-CAT macromolecular crystallography beamlines

Energy Technology Data Exchange (ETDEWEB)

Makarov, O., E-mail: makarov@anl.gov [GM/CA-CAT, Biosciences Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Hilgart, M.; Ogata, C.; Pothineni, S. [GM/CA-CAT, Biosciences Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Cork, C. [Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

2011-09-01

GM/CA-CAT at Sector 23 of the Advanced Photon Source (APS) is an NIH funded facility for crystallographic structure determination of biological macromolecules by X-ray diffraction. A second-generation Berkeley automounter is being integrated into the beamline control system at the 23BM experimental station. This new device replaces the previous all-pneumatic gripper motions with a combination of pneumatics and XYZ motorized linear stages. The latter adds a higher degree of flexibility to the robot including auto-alignment capability, accommodation of a larger capacity sample Dewar of arbitrary shape, and support for advanced operations such as crystal washing, while preserving the overall simplicity and efficiency of the Berkeley automounter design.

Berkeley Lab's Saul Perlmutter wins E.O. Lawrence Award scientist's work on supernovae reveals accelerating universe

CERN Multimedia

2002-01-01

"Saul Perlmutter, a member of Lawrence Berkeley National Laboratory's Physics Division and leader of the international Supernova Cosmology Project based there, has won the Department of Energy's 2002 E.O. Lawrence Award in the physics category" (1/2 page).

Spin-dependent tunnelling in magnetic tunnel junctions

International Nuclear Information System (INIS)

Tsymbal, Evgeny Y; Mryasov, Oleg N; LeClair, Patrick R

2003-01-01

The phenomenon of electron tunnelling has been known since the advent of quantum mechanics, but continues to enrich our understanding of many fields of physics, as well as creating sub-fields on its own. Spin-dependent tunnelling (SDT) in magnetic tunnel junctions (MTJs) has recently aroused enormous interest and has developed in a vigorous field of research. The large tunnelling magnetoresistance (TMR) observed in MTJs garnered much attention due to possible applications in non-volatile random-access memories and next-generation magnetic field sensors. This led to a number of fundamental questions regarding the phenomenon of SDT. In this review article we present an overview of this field of research. We discuss various factors that control the spin polarization and magnetoresistance in MTJs. Starting from early experiments on SDT and their interpretation, we consider thereafter recent experiments and models which highlight the role of the electronic structure of the ferromagnets, the insulating layer, and the ferromagnet/insulator interfaces. We also discuss the role of disorder in the barrier and in the ferromagnetic electrodes and their influence on TMR. (topical review)

Lawrence Berkeley Laboratory Affirmative Action Program. Revised

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-06-01

The Lawrence Berkeley Laboratory`s Affirmative Action Program (AAP) serves as a working document that describes current policies, practices, and results in the area of affirmative action. It represents the Laboratory`s framework for an affirmative approach to increasing the representation of people of color and women in segments of our work force where they have been underrepresented and taking action to increase the employment of persons with disabilities and special disabled and Vietnam era veterans. The AAP describes the hierarchy of responsibility for Laboratory affirmative action, the mechanisms that exist for full Laboratory participation in the AAP, the policies and procedures governing recruitment at all levels, the Laboratory`s plan for monitoring, reporting, and evaluating affirmative action progress, and a description of special affirmative action programs and plans the Laboratory has used and will use in its efforts to increase the representation and retention of groups historically underrepresented in our work force.

Changes in prices, sales, consumer spending, and beverage consumption one year after a tax on sugar-sweetened beverages in Berkeley, California, US: A before-and-after study

Science.gov (United States)

Ryan-Ibarra, Suzanne; Taillie, Lindsey Smith; Induni, Marta

2017-01-01

Background Taxes on sugar-sweetened beverages (SSBs) meant to improve health and raise revenue are being adopted, yet evaluation is scarce. This study examines the association of the first penny per ounce SSB excise tax in the United States, in Berkeley, California, with beverage prices, sales, store revenue/consumer spending, and usual beverage intake. Methods and findings Methods included comparison of pre-taxation (before 1 January 2015) and first-year post-taxation (1 March 2015–29 February 2016) measures of (1) beverage prices at 26 Berkeley stores; (2) point-of-sale scanner data on 15.5 million checkouts for beverage prices, sales, and store revenue for two supermarket chains covering three Berkeley and six control non-Berkeley large supermarkets in adjacent cities; and (3) a representative telephone survey (17.4% cooperation rate) of 957 adult Berkeley residents. Key hypotheses were that (1) the tax would be passed through to the prices of taxed beverages among the chain stores in which Berkeley implemented the tax in 2015; (2) sales of taxed beverages would decline, and sales of untaxed beverages would rise, in Berkeley stores more than in comparison non-Berkeley stores; (3) consumer spending per transaction (checkout episode) would not increase in Berkeley stores; and (4) self-reported consumption of taxed beverages would decline. Main outcomes and measures included changes in inflation-adjusted prices (cents/ounce), beverage sales (ounces), consumers’ spending measured as store revenue (inflation-adjusted dollars per transaction) in two large chains, and usual beverage intake (grams/day and kilocalories/day). Tax pass-through (changes in the price after imposition of the tax) for SSBs varied in degree and timing by store type and beverage type. Pass-through was complete in large chain supermarkets (+1.07¢/oz, p = 0.001) and small chain supermarkets and chain gas stations (1.31¢/oz, p = 0.004), partial in pharmacies (+0.45¢/oz, p = 0.03), and

Archeological Investigations at Big Hill Lake, Southeastern Kansas, 1980.

Science.gov (United States)

1982-09-01

settled primarily along the Neosho river and Labette, Big Hill, and Pumpkin creeks. One of the first settlers in Osage township, in which Big Hill...slabs is not known at present. About 10 years later, in 1876, materials were reported- ly collected from an aboriginal site along Pumpkin creek...and length- ening its lifetime of use. As would therefore be expected, cracks are present between each of the paired holes on both of the two restored

Measurements of the near-surface flow over a hill

Science.gov (United States)

Vosper, S. B.; Mobbs, S. D.; Gardiner, B. A.

2002-10-01

The near-surface flow over a hill with moderate slope and height comparable with the boundary-layer depth is investigated through field measurements of the mean flow (at 2 m), surface pressure, and turbulent momentum flux divergence between 8 and 15 m. The measurements were made along an east-west transect across the hill Tighvein (height 458 m, approximate width 8 km) on the Isle of Arran, south-west Scotland, during two separate periods, each of around three-weeks duration. Radiosonde ascents are used to determine the variation of a Froude number, FL = U/NL, where U is the wind speed at the middle-layer height, hm, N is the mean Brunt-Väisälä frequency below this height and L is a hill length-scale. Measurements show that for moderately stratified flows (for which FL 0.25) a minimum in the hill-induced surface-pressure perturbation occurs across the summit and this is accompanied by a maximum in the near-surface wind speed. In the more strongly stratified case (FL 0.25) the pressure field is more asymmetric and the lee-slope flow is generally stronger than on the windward slope. Such a flow pattern is qualitatively consistent with that predicted by stratified linear boundary-layer and gravity-wave theories. The near-surface momentum budget is analysed by evaluating the dominant terms in a Bernoulli equation suitable for turbulent flow. Measurements during periods of westerly flow are used to evaluate the dominant terms, and the equation is shown to hold to a reasonable approximation on the upwind slope of the hill and also on the downwind slope, away from the summit. Immediately downwind of the summit, however, the Bernoulli equation does not hold. Possible reasons for this, such as non-separated sheltering and flow separation, are discussed.

Tunnel fire dynamics

CERN Document Server

Ingason, Haukur; Lönnermark, Anders

2015-01-01

This book covers a wide range of issues in fire safety engineering in tunnels, describes the phenomena related to tunnel fire dynamics, presents state-of-the-art research, and gives detailed solutions to these major issues. Examples for calculations are provided. The aim is to significantly improve the understanding of fire safety engineering in tunnels. Chapters on fuel and ventilation control, combustion products, gas temperatures, heat fluxes, smoke stratification, visibility, tenability, design fire curves, heat release, fire suppression and detection, CFD modeling, and scaling techniques all equip readers to create their own fire safety plans for tunnels. This book should be purchased by any engineer or public official with responsibility for tunnels. It would also be of interest to many fire protection engineers as an application of evolving technical principles of fire safety.

Novedades sobre el género Pilosella Hill.: (Asteraceae, Lactuceae) en España, II

OpenAIRE

Mateo Sanz, Gonzalo

2016-01-01

Se comunica la presencia de diversas especies nuevas del género Pilosella Hill. (Asteraceae, Lactuceae) en España. Novelties on the genus Pilosella Hill (Asteraceae, Lactuceae) in Spain, II. Several species of Pilosella Hill (Asteraceae, Lactuceae) found in Spain.

Proton tunneling in solids

Energy Technology Data Exchange (ETDEWEB)

Kondo, J.

1998-10-01

The tunneling rate of the proton and its isotopes between interstitial sites in solids is studied theoretically. The phonons and/or the electrons in the solid have two effects on the tunneling phenomenon. First, they suppress the transfer integral between two neighbouring states. Second, they give rise to a finite lifetime of the proton state. Usually the second effect is large and the tunneling probability per unit time (tunneling rate) can be defined. In some cases, however, a coherent tunneling is expected and actually observed. (author)

Proton tunneling in solids

International Nuclear Information System (INIS)

Kondo, J.

1998-01-01

The tunneling rate of the proton and its isotopes between interstitial sites in solids is studied theoretically. The phonons and/or the electrons in the solid have two effects on the tunneling phenomenon. First, they suppress the transfer integral between two neighbouring states. Second, they give rise to a finite lifetime of the proton state. Usually the second effect is large and the tunneling probability per unit time (tunneling rate) can be defined. In some cases, however, a coherent tunneling is expected and actually observed. (author)

George William Hill, the Great but Unknown 19th Century Celestial Mechanician

Science.gov (United States)

Corbin, Brenda G.

2012-01-01

George William Hill (1838-1914) has long been considered one of the most famous and talented celestial mechanicians of the past century and a half. However, many people have never heard of him and his work. Simon Newcomb said he "will easily rank as the greatest master of mathematical astronomy during the last quarter of the nineteenth century.” After receiving a B.A. at Rutgers in 1859, Hill began work in 1861 at the office of the American Ephemeris and Nautical Almanac in Cambridge, MA. He moved to Washington with the group in 1882 which then became part of the U. S. Naval Observatory. Newcomb, beginning his work on planetary motion, assigned the theory of Jupiter and Saturn to him, calling it about the most difficult topic. Hill's work was published by the USNO in 1890 as A New Theory of Jupiter and Saturn. From 1898 to 1901, Hill lectured on the subject of celestial mechanics at Columbia University in a position created just for him. After 1892 and until his death, he lived at the family homestead in West Nyack, NY. He never married, was something of a recluse, and spent most of his time with his books and research. Hill was an amateur botanist and enjoyed exploring on long walks in the countryside. Many honors and awards came to him during his lifetime, both from the U.S. and abroad, including serving as president of the American Mathematical Society. All of Hill's mathematical and astronomical research was incorporated in The Collected Mathematical Works of George William Hill. This work, containing a preface in French by Poincare, was published in 4 large volumes by the Carnegie Institution of Washington in 1905.

Environmental surveillance program of the Lawrence Berkeley Laboratory

International Nuclear Information System (INIS)

Thomas, R.H.

1976-04-01

The major radiological environmental impact of the Lawrence Berkeley Laboratory is due to the operation of four particle accelerators. Potential sources of population exposure at the Laboratory are discussed. The major source of population exposure due to accelerator operation arises from the prompt radiation field which consists principally of neutrons and photons. Release of small quantities of radionuclides is also a potential source of population exposure but is usually an order of magnitude less significant. Accelerator produced radiation levels at the Laboratory boundary are comparable with the magnitudes of the fluctuations found in the natural background radiation. Environmental monitoring of accelerator-produced radiation and of radionuclides is carried on throughout the Laboratory, at the Laboratory perimeter, and in the regions surrounding the Laboratory. The techniques used are described. The models used to calculate population exposure are described and discussed

The Advanced Light Source at Lawrence Berkeley Laboratory

International Nuclear Information System (INIS)

Robinson, A.L.; Perera, R.C.C.; Schlachter, A.S.

1991-10-01

The Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory (LBL), scheduled to be operational in the spring of 1993 as a US Department of Energy national user facility, will be a next- generation source of soft x-ray and ultraviolet (XUV) synchrotron radiation. Undulators will provide the world's brightest synchrotron radiation at photon energies from below 10 eV to above 2 keV; wiggler and bend-magnet radiation will extend the spectral coverage with high fluxes above 10 keV. These capabilities will support an extensive research program in a broad spectrum of scientific and technological areas in which XUV radiation is used to study and manipulate matter in all its varied gaseous, liquid, and solid forms. The ALS will also serve those interested in developing the fabrication technology for micro- and nanostructures, as well as characterizing them

An Evaluation of the New Curriculum at the University of California, Berkeley, School of Optometry.

Science.gov (United States)

Harris, Michael G.; Kashani, Sandy; Saroj, Namrata

2001-01-01

Evaluated the new curriculum at the University of California, Berkeley, School of Optometry by comparing the content of the new curriculum to the old curriculum and by surveying faculty and students regarding their opinion of the new curriculum. Findings indicated that the curriculum is successful in implementing desired changes, including reduced…

Multi-scale habitat use of male ruffed grouse in the Black Hills National Forest

Science.gov (United States)

Cassandra L. Mehls; Kent C. Jensen; Mark A. Rumble; Michael C. Wimberly

2014-01-01

Ruffed grouse (Bonasa umbellus) are native upland game birds and a management indicator species (MIS) for aspen (Populus tremuloides) in the Black Hills National Forest (Black Hills). Our objective was to assess resource selection of male ruffed grouse to identify the most appropriate scale to manage for aspen and ruffed grouse in the Black Hills. During spring 2007...

Site Environmental Report for 2011, Volumes 1& 2

Energy Technology Data Exchange (ETDEWEB)

Baskin, David; Bauters, Tim; Borglin, Ned; Fox, Robert; Horst, Blair; Jelinski, John; Lackner, Ginny; Philliber, Jeff; Rothermich, Nancy; Thorson, Patrick; Wahl, Linnea; Xu, Suying

2012-09-12

The Site Environmental Report for 2011 summarizes Berkeley Lab’s environmental management performance, presents environmental monitoring results, and describes significant programs for calendar year (CY) 2011. Throughout this report, “Berkeley Lab” or “LBNL” refers both to (1) the multiprogram scientific facility the UC manages and operates on the 202-acre university-owned site located in the hills above the UC Berkeley campus, and the site itself, and (2) the UC as managing and operating contractor for Ernest Orlando Lawrence Berkeley National Laboratory. The report is separated into two volumes. Volume I is organized into an executive summary followed by six chapters that include an overview of LBNL, a discussion of its Environmental Management System (EMS), the status of environmental programs, summarized results from surveillance and monitoring activities, and quality assurance (QA) measures. Volume II contains individual data results from surveillance and monitoring activities.

Fluctuation Dominated Josephson Tunneling with a Scanning Tunneling Microscope

International Nuclear Information System (INIS)

Naaman, O.; Teizer, W.; Dynes, R. C.

2001-01-01

We demonstrate Josephson tunneling in vacuum tunnel junctions formed between a superconducting scanning tunneling microscope tip and a Pb film, for junction resistances in the range 50--300 k Omega. We show that the superconducting phase dynamics is dominated by thermal fluctuations, and that the Josephson current appears as a peak centered at small finite voltage. In the presence of microwave fields (f=15.0 GHz) the peak decreases in magnitude and shifts to higher voltages with increasing rf power, in agreement with theory

The ISI Tunnel

Science.gov (United States)

1993-10-01

DP /etc/tunnelvisa p zephyr dark -star TCP /etc/tunnelvisa p zephyr dak’star ICMP /etc/tunnelvisa p zephyr quark MDP /etc/tunnelvisa p zephyr quark ...drax-net-yp 128.9.32.2 1 route add quark -net-yp 128.9.32.3 1 route add vlsi-net-yp 128.9.32.4 1 route add darkstar-net-yp 128.9.32.3 1 route add rocky...TCP /etc/tunnel-visa p zephyr quark ICMP /etc/tunnel-visa p zephyr drax tTI)P /etc/tunnel-visa p zephyr drax TCP /etc/tunnel_visa p zephyr drax ICMP

Validity and Reliability of Preschool, First and Second Grade Versions of Berkeley Parenting Self-Efficacy Scale

Directory of Open Access Journals (Sweden)

Shahrbanoo Tajeri

2009-02-01

Full Text Available "nObjective: The purpose of this study is to examine the factor structure, internal consistency, and construct validity of preschool, first and second grade versions of Berkeley Parenting self-efficacy scale. "nMethod:  The subjects were 317 mothers: (102 mothers of preschool children, 111 mothers of first grade children and 104 mothers of second grade children who were randomly selected from schools in Tehran. They completed Berkeley parenting self-efficacy and Rotter `s locus of control scales. Factor analysis using the principle component method was used to identify the factor structure of parenting self-efficacy scale. Cronbach`s alpha coefficient was used to identify the reliability of parenting self efficacy scale. "nResults: Results of this study indicated that the cronbach`s alpha coefficient was 0.84, 0.87, 0.64 for preschool, first grade and second grade versions respectively. Based on the scree test ,,factor analysis produced two factors of maternal strategy and child outcome, and it also produced the highest level of total variance explained by these 2 factors. The Parenting self-efficacy scale was negatively associated with measure of locus of control(r=-0.54 for the preschool version, -0.64 for the first grade version and -0.54 for the second grade version. "nConclusion: Due to relatively high reliability and validity of preschool, first and second grade versions of Berkeley Parenting Self-Efficacy scale, this scale could be used as a reliable and valid scale in other research areas

Resonant tunnel magnetoresistance in a double magnetic tunnel junction

KAUST Repository

Useinov, Arthur; Useinov, Niazbeck Kh H; Tagirov, Lenar R.; Kosel, Jü rgen

2011-01-01

We present quasi-classical approach to calculate a spin-dependent current and tunnel magnetoresistance (TMR) in double magnetic tunnel junctions (DMTJ) FML/I/FMW/I/FMR, where the magnetization of the middle ferromagnetic metal layer FMW can

Public census data on CD-ROM at Lawrence Berkeley Laboratory

Energy Technology Data Exchange (ETDEWEB)

Merrill, D.W.

1992-07-02

In connection with the Comprehensive Epidemiologic Data Resource (CEDR) and Populations at Risk to Environmental Pollution (PAREP) projects, of the Information and Computing Sciences Division (ICSD) at Lawrence Berkeley Laboratory (LBL), are using public socioeconomic and geographic data files which are available to CEDR and PAREP collaborators via LBL's computing network. At this time 67 CD-ROM diskettes (approximately 35 gigabytes) are on line via the Unix file server cedrcd.lbl.gov. Most of the files are from the US Bureau of the Census, and most pertain to the 1990 Census of Population and Housing. This paper contains a list of the CD-ROMs available.

Tunneling through landsliding zone; Jisuberi chitainai no tunnel seko

Energy Technology Data Exchange (ETDEWEB)

Konbu, A; Hatabu, K; Kano, T [Tekken Corp., Tokyo (Japan)

1994-08-01

At the new tunnel construction site of the Shirakata tunnel on the Obama line in Yamaguchi Prefecture, a landsliding occurred at about 60 meters to the upper portion obliquely to the right hand side of the shaft when the excavation progressed to about 10 meters from the starting side. The landslide caused displacement at the shaft opening and change in the supports. As a result of the re-investigation, it was confirmed that the slide face went through the tunnel cross section. The measures taken were removal of the upper soil and an adoption of the all ground fastening (AGF) method (injection type long tip fastening method) as an auxiliary construction to stop loosening of the natural ground associated with the tunnel excavation. The result was a completion of tunneling the landsliding zone without a problem. This paper reports the AGF method adopted in the above construction, together with the construction works and natural ground conditions. The AGF method is about the same as the pipe roof method with regard to the natural ground accepting mechanism and the materials used. The difference is building an improved body in a limited area in the natural ground around the steel pipes by injecting the fixing material. The use of this method caused no problems in subsidence and displacement in the surrounding ground, and completed the tunneling construction without an unusual event. 1 ref., 7 figs., 2 tabs.

LAUE lens development at UC Berkeley: status and prospects

Science.gov (United States)

Barrière, Nicolas M.; Tomsick, John A.; Ackermann, Marcelo D.; Bastie, Pierre; Boggs, Steven E.; Hanlon, Lorraine; Jentschel, Michael; Lowell, Alexander; Roudil, Gilles; von Ballmoos, Peter; Wade, Colin

2013-09-01

We report on the status of the Laue lens development effort led by UC Berkeley, where a dedicated X-ray beamline and a Laue lens assembly station were built. This allowed the realization of a first lens prototype in June 2012. Based on this achievement, and thanks to a new NASA APRA grant, we are moving forward to enable Laue lenses. Several parallel activities are in progress. Firstly, we are refining the method to glue quickly and accurately crystals on a lens substrate. Secondly, we are conducting a study of high-Z crystals to diffract energies up to 900 keV efficiently. And thirdly, we are exploring new concepts of Si-based lenses that could further improve the focusing capabilities, and thus the sensitivity of Laue lenses.

Development of the tunneling junction simulation environment for scanning tunneling microscope evaluation

International Nuclear Information System (INIS)

Gajewski, Krzysztof; Piasecki, Tomasz; Kopiec, Daniel; Gotszalk, Teodor

2017-01-01

Proper configuration of scanning tunneling microscope electronics plays an important role in the atomic scale resolution surface imaging. Device evaluation in the tunneling contact between scanning tip and sample may be prone to the surface quality or mechanical disturbances. Thus the use of tunneling junction simulator makes electronics testing more reliable and increases its repeatability. Here, we present the theoretical background enabling the proper selection of electronic components circuitry used as a tunneling junction simulator. We also show how to simulate mechanics related to the piezoelectric scanner, which is applied in real experiments. Practical use of the proposed simulator and its application in metrological characterization of the developed scanning tunneling microscope is also shown. (paper)

Numerical Simulation Analysis of Seismic of Frame Structure on Hill Terrain

Directory of Open Access Journals (Sweden)

Weng Weisu

2017-01-01

Full Text Available In recent year, Wenchuan,Ya’an,Yushu and other areas in china occur a series of high earthquake, however areas of earthquake is similar as mountainous terrain, building structure of seismic increasingly aroused our concern, and the research that hill topography affected building structure seismic in shallow mountain. The research content mainly includes: through modelling was built by the ANSYS software, the cooperative effects of a ten layer of frame structure- hill system were calculation. First, simple comparative dynamic characteristics analysis of soil - structure interaction and the rigid foundation assumption conditions; Second, put Hill-Soil-Structure Interaction(referred to as HSSI and Soil - Structure - Interaction(referred to as SSI further analysis of the dynamic response, including: including structural modal analysis (vibration mode, cycle, the time history analysis (such as displacement, internal force and acceleration and so on. Through Hill-Soil-Structure Interaction research, taking each factor in consideration, giving structure seismic key technology measures about shallow mountain to provide reference for such structure theory research.

Fabrication of magnetic tunnel junctions with a single-crystalline LiF tunnel barrier

Science.gov (United States)

Krishna Narayananellore, Sai; Doko, Naoki; Matsuo, Norihiro; Saito, Hidekazu; Yuasa, Shinji

2018-04-01

We fabricated Fe/LiF/Fe magnetic tunnel junctions (MTJs) by molecular beam epitaxy on a MgO(001) substrate, where LiF is an insulating tunnel barrier with the same crystal structure as MgO (rock-salt type). Crystallographical studies such as transmission electron microscopy and nanobeam electron diffraction observations revealed that the LiF tunnel barrier is single-crystalline and has a LiF(001)[100] ∥ bottom Fe(001)[110] crystal orientation, which is constructed in the same manner as MgO(001) on Fe(001). Also, the in-plane lattice mismatch between the LiF tunnel barrier and the Fe bottom electrode was estimated to be small (about 0.5%). Despite such advantages for the tunnel barrier of the MTJ, the observed tunnel magnetoresistance (MR) ratio was low (˜6% at 20 K) and showed a significant decrease with increasing temperature (˜1% at room temperature). The results imply that indirect tunneling and/or thermally excited carriers in the LiF tunnel barrier, in which the current basically is not spin-polarized, play a major role in electrical transport in the MTJ.

DOE to accept bids for Elk Hills crude

International Nuclear Information System (INIS)

Anon.

1992-01-01

This paper reports that the Department of Energy will accept bids in a reoffering sale covering 53,400 b/d of Elk Hills field oil but later may exercise an option to cut sales volumes and ship 20,000 b/d to Strategic Petroleum Reserve sites in Texas. DOE rejected all 19 bids submitted in an earlier semiannual sale of crude oil from the California naval petroleum reserve, saying they were too low. DOE the, The unique combination of federal and state government policies affecting the movement of oil into and out of the California market has contributed to a situation in which it apparently is very difficult for the government to receive a price for Elk Hills oil that satisfies the minimum price tests that govern the sale of Elk Hills oil. The 12 winning bids in the reoffering sale averaged $13.58/bbl, with bids for the higher quality Stevens zone crude averaging $13.92/bbl, about 67 cents/bbl higher than bids rejected last month. DOE the 20,000 b/d is all local pipelines can ship to the interstate All-American pipeline for transfer to Texas beginning in June

Resonant tunneling via spin-polarized barrier states in a magnetic tunnel junction

NARCIS (Netherlands)

Jansen, R.; Lodder, J.C.

2000-01-01

Resonant tunneling through states in the barrier of a magnetic tunnel junction has been analyzed theoretically for the case of a spin-polarized density of barrier states. It is shown that for highly spin-polarized barrier states, the magnetoresistance due to resonant tunneling is enhanced compared

Quantum tunneling time

International Nuclear Information System (INIS)

Wang, Z.S.; Lai, C.H.; Oh, C.H.; Kwek, L.C.

2004-01-01

We present a calculation of quantum tunneling time based on the transition duration of wave peak from one side of a barrier to the other. In our formulation, the tunneling time comprises a real and an imaginary part. The real part is an extension of the phase tunneling time with quantum corrections whereas the imaginary time is associated with energy derivatives of the probability amplitudes

Rare Plants and Animals of the Texas Hill Country: Educator's Guide.

Science.gov (United States)

Texas State Dept. of Parks and Wildlife, Austin.

Texas Hill Country is a land of fresh water springs, stony hills, and steep canyons and home to many rare plants and animals. Six activities for grades 3-5 and six activities for grades 6-12 are contained in this guide. Elementary activity highlights include using "The Lorax" by Dr. Seuss to stimulate critical thinking about…

Follow the Money: Engineering at Stanford and UC Berkeley during the Rise of Silicon Valley

Science.gov (United States)

Adams, Stephen B.

2009-01-01

A comparison of the engineering schools at UC Berkeley and Stanford during the 1940s and 1950s shows that having an excellent academic program is necessary but not sufficient to make a university entrepreneurial (an engine of economic development). Key factors that made Stanford more entrepreneurial than Cal during this period were superior…

Measuring fire size in tunnels

International Nuclear Information System (INIS)

Guo, Xiaoping; Zhang, Qihui

2013-01-01

A new measure of fire size Q′ has been introduced in longitudinally ventilated tunnel as the ratio of flame height to the height of tunnel. The analysis in this article has shown that Q′ controls both the critical velocity and the maximum ceiling temperature in the tunnel. Before the fire flame reaches tunnel ceiling (Q′ 1.0), Fr approaches a constant value. This is also a well-known phenomenon in large tunnel fires. Tunnel ceiling temperature shows the opposite trend. Before the fire flame reaches the ceiling, it increases very slowly with the fire size. Once the flame has hit the ceiling of tunnel, temperature rises rapidly with Q′. The good agreement between the current prediction and three different sets of experimental data has demonstrated that the theory has correctly modelled the relation among the heat release rate of fire, ventilation flow and the height of tunnel. From design point of view, the theoretical maximum of critical velocity for a given tunnel can help to prevent oversized ventilation system. -- Highlights: • Fire sizing is an important safety measure in tunnel design. • New measure of fire size a function of HRR of fire, tunnel height and ventilation. • The measure can identify large and small fires. • The characteristics of different fire are consistent with observation in real fires

Microwave-induced co-tunneling in single electron tunneling transistors

DEFF Research Database (Denmark)

Ejrnaes, M.; Savolainen, M.; Manscher, M.

2002-01-01

on rubber bellows. Cross-talk was minimized by using individual coaxial lines between the sample and the room temperature electronics: The co-tunneling experiments were performed at zero DC bias current by measuring the voltage response to a very small amplitude 2 Hz current modulation with the gate voltage......The influence of microwaves on the co-tunneling in single electron tunneling transistors has been investigated as function of frequency and power in the temperature range from 150 to 500 mK. All 20 low frequency connections and the RF line were filtered, and the whole cryostat was suspended...

Conditioning exercises in ski jumping: biomechanical relationship of squat jumps, imitation jumps, and hill jumps.

Science.gov (United States)

Lorenzetti, Silvio; Ammann, Fabian; Windmüller, Sabrina; Häberle, Ramona; Müller, Sören; Gross, Micah; Plüss, Michael; Plüss, Stefan; Schödler, Berni; Hübner, Klaus

2017-11-22

As hill jumps are very time-consuming, ski jumping athletes often perform various imitation jumps during training. The performed jumps should be similar to hill jumps, but a direct comparison of the kinetic and kinematic parameters has not been performed yet. Therefore, this study aimed to correlate 11 common parameters during hill jumps (Oberstdorf Germany), squat jumps (wearing indoor shoes), and various imitation jumps (rolling 4°, rolling flat, static; jumping equipment or indoor shoes) on a custom-built instrumented vehicle with a catch by the coach. During the performed jumps, force and video data of the take-off of 10 athletes were measured. The imitation and squat jumps were then ranked. The main difference between the hill jumps and the imitation and squat jumps is the higher maximal force loading rate during the hill jumps. Imitation jumps performed on a rolling platform, on flat ground were the most similar to hill jumps in terms of the force-time, and leg joint kinematic properties. Thus, non-hill jumps with a technical focus should be performed from a rolling platform with a flat inrun with normal indoor shoes or jumping equipment, and high normal force loading rates should be the main focus of imitation training.

Influence of trap-assisted tunneling on trap-assisted tunneling current in double gate tunnel field-effect transistor

International Nuclear Information System (INIS)

Jiang Zhi; Zhuang Yi-Qi; Li Cong; Wang Ping; Liu Yu-Qi

2016-01-01

Trap-assisted tunneling (TAT) has attracted more and more attention, because it seriously affects the sub-threshold characteristic of tunnel field-effect transistor (TFET). In this paper, we assess subthreshold performance of double gate TFET (DG-TFET) through a band-to-band tunneling (BTBT) model, including phonon-assisted scattering and acoustic surface phonons scattering. Interface state density profile (D it ) and the trap level are included in the simulation to analyze their effects on TAT current and the mechanism of gate leakage current. (paper)

Public census data on CD-ROM at Lawrence Berkeley Laboratory

Energy Technology Data Exchange (ETDEWEB)

Merrill, D.W.

1993-01-16

The Comprehensive Epidemiologic Data Resource (CEDR) and Populations at Risk to Environmental Pollution (PAREP) projects, of the Information and Computing Sciences Division (ICSD) at Lawrence Berkeley Laboratory (LBL), are using public socioeconomic and geographic data files which are available to CEDR and PAREP collaborators via LBL's computing network. At this time 72 CD-ROM diskettes (approximately 37 gigabytes) are on line via the Unix file server cedrcd.lbl.gov''. Most of the files are from the US Bureau of the Census, and many of these pertain to the 1990 Census of Population and Housing. All the CD-ROM diskettes contain documentation in the form of ASCII text files. In addition, printed documentation for most files is available for inspection at University of California Data and Technical Assistance (UC DATA), tel. (510) 642-6571, or the UC Documents Library, tel. (510) 642-2569, both located on the UC Berkeley Campus. Many of the CD-ROM diskettes distributed by the Census Bureau contain software for PC compatible computers, for easily accessing the data. Shared access to the data is maintained through a collaboration among the CEDR and PAREP projects at LBL, and UC DATA, and the UC Documents Library. LBL is grateful to UC DATA and the UC Documents Library for the use of their CD-ROM diskettes. Shared access to LBL facilities may be restricted in the future if costs become prohibitive. Via the Sun Network File System (NFS), these data can be exported to Internet computers for direct access by the user's application program(s). Due to the size of the files, this access method is preferred over File Transfer Protocol (FTP) access. Please contact Deane Merrill (dwmerrill lbl.gov) if you wish to make use of the data.

Thermovoltages in vacuum tunneling investigated by scanning tunneling microscopy

OpenAIRE

Hoffmann, D. H.; Rettenberger, Armin; Grand, Jean Yves; Läuger, K.; Leiderer, Paul; Dransfeld, Klaus; Möller, Rolf

1995-01-01

By heating the tunneling tip of a scanning tunneling microscope the thermoelectric properties of a variable vacuum barrier have been investigated. The lateral variation of the observed thermovoltage will be discussed for polycrystalline gold, stepped surfaces of silver, as well as for copper islands on silver.

Distance-Based Functional Diversity Measures and Their Decomposition: A Framework Based on Hill Numbers

Science.gov (United States)

Chiu, Chun-Huo; Chao, Anne

2014-01-01

Hill numbers (or the “effective number of species”) are increasingly used to characterize species diversity of an assemblage. This work extends Hill numbers to incorporate species pairwise functional distances calculated from species traits. We derive a parametric class of functional Hill numbers, which quantify “the effective number of equally abundant and (functionally) equally distinct species” in an assemblage. We also propose a class of mean functional diversity (per species), which quantifies the effective sum of functional distances between a fixed species to all other species. The product of the functional Hill number and the mean functional diversity thus quantifies the (total) functional diversity, i.e., the effective total distance between species of the assemblage. The three measures (functional Hill numbers, mean functional diversity and total functional diversity) quantify different aspects of species trait space, and all are based on species abundance and species pairwise functional distances. When all species are equally distinct, our functional Hill numbers reduce to ordinary Hill numbers. When species abundances are not considered or species are equally abundant, our total functional diversity reduces to the sum of all pairwise distances between species of an assemblage. The functional Hill numbers and the mean functional diversity both satisfy a replication principle, implying the total functional diversity satisfies a quadratic replication principle. When there are multiple assemblages defined by the investigator, each of the three measures of the pooled assemblage (gamma) can be multiplicatively decomposed into alpha and beta components, and the two components are independent. The resulting beta component measures pure functional differentiation among assemblages and can be further transformed to obtain several classes of normalized functional similarity (or differentiation) measures, including N-assemblage functional generalizations of

Distance-based functional diversity measures and their decomposition: a framework based on Hill numbers.

Directory of Open Access Journals (Sweden)

Chun-Huo Chiu

Full Text Available Hill numbers (or the "effective number of species" are increasingly used to characterize species diversity of an assemblage. This work extends Hill numbers to incorporate species pairwise functional distances calculated from species traits. We derive a parametric class of functional Hill numbers, which quantify "the effective number of equally abundant and (functionally equally distinct species" in an assemblage. We also propose a class of mean functional diversity (per species, which quantifies the effective sum of functional distances between a fixed species to all other species. The product of the functional Hill number and the mean functional diversity thus quantifies the (total functional diversity, i.e., the effective total distance between species of the assemblage. The three measures (functional Hill numbers, mean functional diversity and total functional diversity quantify different aspects of species trait space, and all are based on species abundance and species pairwise functional distances. When all species are equally distinct, our functional Hill numbers reduce to ordinary Hill numbers. When species abundances are not considered or species are equally abundant, our total functional diversity reduces to the sum of all pairwise distances between species of an assemblage. The functional Hill numbers and the mean functional diversity both satisfy a replication principle, implying the total functional diversity satisfies a quadratic replication principle. When there are multiple assemblages defined by the investigator, each of the three measures of the pooled assemblage (gamma can be multiplicatively decomposed into alpha and beta components, and the two components are independent. The resulting beta component measures pure functional differentiation among assemblages and can be further transformed to obtain several classes of normalized functional similarity (or differentiation measures, including N-assemblage functional

The Hill's three-body problem: a new deduction of motion equations

International Nuclear Information System (INIS)

Fuente Marcos, C. de la.

1995-01-01

Although the Hill's problem has been considered traditionally as a particular case of the restricted problem, it is not but rather a different problem with the same degree of generality. In this paper it is presented a new derivation of the motion equations obtained originally by Hill in 1878 as well as a brief discussion about its possible applications. (Author) 13 refs

Effects of mineralogy on sorption of strontium and cesium onto Calico Hills Tuff

International Nuclear Information System (INIS)

Meyer, R.E.; Arnold, W.D.; Case, F.I.; O'Kelley, G.D.; Land, J.F.

1990-04-01

The sorption properties of tuff formations at the proposed site for the high-level nuclear waste repository at Yucca Mountain, Nevada, have been extensively studied. Sorption and desorption measurements were made of strontium and cesium onto clinoptilolite and Calico Hills Tuff. The object was to see whether there was a correlation between sorption of strontium and cesium onto Calico Hills Tuff and the sorption of strontium and cesium onto clinoptilolite based on the content of clinoptilolite in the Calico Hills Tuff. 13 refs., 10 figs., 6 tabs

Macroscopic quantum tunneling in Josephson tunnel junctions and Coulomb blockade in single small tunnel junctions

International Nuclear Information System (INIS)

Cleland, A.N.

1991-04-01

Experiments investigating the process of macroscopic quantum tunneling in a moderately-damped, resistively shunted, Josephson junction are described, followed by a discussion of experiments performed on very small capacitance normal-metal tunnel junctions. The experiments on the resistively-shunted Josephson junction were designed to investigate a quantum process, that of the tunneling of the Josephson phase variable under a potential barrier, in a system in which dissipation plays a major role in the dynamics of motion. All the parameters of the junction were measured using the classical phenomena of thermal activation and resonant activation. Theoretical predictions are compared with the experimental results, showing good agreement with no adjustable parameters; the tunneling rate in the moderately damped (Q ∼ 1) junction is seen to be reduced by a factor of 300 from that predicted for an undamped junction. The phase is seen to be a good quantum-mechanical variable. The experiments on small capacitance tunnel junctions extend the measurements on the larger-area Josephson junctions from the region in which the phase variable has a fairly well-defined value, i.e. its wavefunction has a narrow width, to the region where its value is almost completely unknown. The charge on the junction becomes well-defined and is predicted to quantize the current through the junction, giving rise to the Coulomb blockade at low bias. I present the first clear observation of the Coulomb blockade in single junctions. The electrical environment of the tunnel junction, however, strongly affects the behavior of the junction: higher resistance leads are observed to greatly sharpen the Coulomb blockade over that seen with lower resistance leads. I present theoretical descriptions of how the environment influences the junctions; comparisons with the experimental results are in reasonable agreement

Presentation of the National Center for Research in Vocational Education [Berkeley, California] at the AVA Annual Conference.

Science.gov (United States)

National Center for Research in Vocational Education, Berkeley, CA.

This collection contains the following conference presentations about the National Center for Research in Vocational Education at the University of California at Berkeley: "Visions and Principles" (Charles Benson); "How the Center Sees Its Role" (Gordon Swanson); "The Research Agenda" (Sue Berryman); "The Service…

About tunnelling times

International Nuclear Information System (INIS)

Olkhovsky, V.S.; Recami, E.

1991-08-01

In this paper, first we critically analyse the main theoretical definitions and calculations of the sub-barrier tunnelling and reflection times. Secondly, we propose a new, physically sensible definition of such durations, on the basis of a recent general formalism (already tested for other types of quantum collisions). At last, we discuss some results regarding temporal evolution of the tunnelling processes, and in particular the ''particle'' speed during tunnelling. (author). 36 refs, 1 fig

Guide to the NITRD Program FY 2004-FY 2005. Supplement to the President’s Budget for FY 2005

Science.gov (United States)

2004-12-01

and Professor University of California, Berkeley J. Carter Beese , Jr. President Riggs Capital Partners Pedro Celis, Ph.D. Software Architect Microsoft...University of North Carolina at Chapel Hill William J. Hannigan President AT&T Jonathan C. Javitt, M.D., M.P.H. Senior Fellow Potomac Institute for Policy

Tunneling current between graphene layers

OpenAIRE

Poklonski, Nikolai A.; Siahlo, Andrei I.; Vyrko, Sergey A.; Popov, Andrey M.; Lozovik, Yurii E.

2013-01-01

The physical model that allows to calculate the values of the tunneling current be-tween graphene layers is proposed. The tunneling current according to the pro-posed model is proportional to the area of tunneling transition. The calculated value of tunneling conductivity is in qualitative agreement with experimental data.

Analysis of automobile’s automatic control systems for the hill climbing start

Directory of Open Access Journals (Sweden)

Valeriy I. Klimenko

2014-12-01

Full Text Available To improve road safety while driving on the rise, facilitating the driver’s activity the automobile industry leaders are introducing automatic hill-hold control systems into the car design. This study purpose relates to the existing automatic start control systems’ design analysis. Analyzed are the existing design developments of automatic hill start assist control systems applied for driving at the start of the climbing. The effected research allows to select the scheme for further development of start driving automatic control systems. Further improvement of driving control systems and primarily the driver assistance hill-hold control systems is necessary to increase both the driving comfort and the traffic safety.

Life sciences: Lawrence Berkeley Laboratory, 1988

International Nuclear Information System (INIS)

1989-07-01

Life Sciences Research at LBL has both a long history and a new visibility. The physics technologies pioneered in the days of Ernest O. Lawrence found almost immediate application in the medical research conducted by Ernest's brother, John Lawrence. And the tradition of nuclear medicine continues today, largely uninterrupted for more than 50 years. Until recently, though, life sciences research has been a secondary force at the Lawrence Berkeley Laboratory (LBL). Today, a true multi-program laboratory has emerged, in which the life sciences participate as a full partner. The LBL Human Genome Center is a contribution to the growing international effort to map the human genome. Its achievements represent LBL divisions, including Engineering, Materials and Chemical Sciences, and Information and Computing Sciences, along with Cell and Molecular Biology and Chemical Biodynamics. The Advanced Light Source Life Sciences Center will comprise not only beamlines and experimental end stations, but also supporting laboratories and office space for scientists from across the US. This effort reflects a confluence of scientific disciplines --- this time represented by individuals from the life sciences divisions and by engineers and physicists associated with the Advanced Light Source project. And finally, this report itself, the first summarizing the efforts of all four life sciences divisions, suggests a new spirit of cooperation. 30 figs

Single Electron Tunneling

International Nuclear Information System (INIS)

Ruggiero, Steven T.

2005-01-01

Financial support for this project has led to advances in the science of single-electron phenomena. Our group reported the first observation of the so-called ''Coulomb Staircase'', which was produced by tunneling into ultra-small metal particles. This work showed well-defined tunneling voltage steps of width e/C and height e/RC, demonstrating tunneling quantized on the single-electron level. This work was published in a now well-cited Physical Review Letter. Single-electron physics is now a major sub-field of condensed-matter physics, and fundamental work in the area continues to be conducted by tunneling in ultra-small metal particles. In addition, there are now single-electron transistors that add a controlling gate to modulate the charge on ultra-small photolithographically defined capacitive elements. Single-electron transistors are now at the heart of at least one experimental quantum-computer element, and single-electron transistor pumps may soon be used to define fundamental quantities such as the farad (capacitance) and the ampere (current). Novel computer technology based on single-electron quantum dots is also being developed. In related work, our group played the leading role in the explanation of experimental results observed during the initial phases of tunneling experiments with the high-temperature superconductors. When so-called ''multiple-gap'' tunneling was reported, the phenomenon was correctly identified by our group as single-electron tunneling in small grains in the material. The main focus throughout this project has been to explore single electron phenomena both in traditional tunneling formats of the type metal/insulator/particles/insulator/metal and using scanning tunneling microscopy to probe few-particle systems. This has been done under varying conditions of temperature, applied magnetic field, and with different materials systems. These have included metals, semi-metals, and superconductors. Amongst a number of results, we have

Drill and blast tunnelling; Konvensjonell drift av tunneler

Energy Technology Data Exchange (ETDEWEB)

Roenn, Paal-Egil

1997-12-31

This thesis treats drill and blast tunnelling. The rapid technological advance necessitates revised and updated design criteria, quality requirements and quality control. In situ blast experiments were carried out in order to test new methods and improve the basis for calculation and design. The main topics of the experiments were (1) longer rounds and increased drillhole diameter, (2) emulsion slurry as explosives in tunnelling, and (3) electronic detonators in contour blasting. The experiments show that it is technically feasible to blast rounds of up to 8.6 m length. Using current technology, the economical optimum round length is substantially shorter. Dust, low visibility, noise and toxic fumes are occupational environmental strains for the tunnel workers. Several of the environmental factors are strongly influenced by the type of explosives used. For example, emulsion slurry resulted in 4 to 5 times better visibility than Anolit and the concentration of respirable dust and total dust was reduced by 30-50 %. Electronic detonators were tested and found to give a higher percentage of remaining drillholes in the contour than Nonel detonators. The thesis includes a chapter on economic design of hydropower tunnels. 42 refs., 83 figs., 45 tabs.

Resonant tunnel magnetoresistance in double-barrier planar magnetic tunnel junctions

KAUST Repository

Useinov, A. N.

2011-08-24

We present a theoretical approach to calculate the spin-dependent current and tunnel magnetoresistance (TMR) in a double-barrier magnetic tunnel junction (DMTJ), in which the magnetization of the middle ferromagnetic metal layer can be aligned parallel or antiparallel in relation to the fixed magnetizations of the left and right ferromagnetic electrodes. The electron transport through the DMTJ is considered as a three-dimensional problem, taking into account all transmitting electron trajectories as well as the spin-dependent momentum conservation law. The dependence of the transmission coefficient and spin-polarized currents on the applied voltage is derived as an exact solution to the quantum-mechanical problem for the spin-polarized transport. In the range of the developed physical model, the resonant tunneling, nonresonant tunneling, and enhanced spin filtering can be explained; the simulation results are in good agreement with experimental data.

Resonant tunnel magnetoresistance in double-barrier planar magnetic tunnel junctions

KAUST Repository

Useinov, A. N.; Kosel, Jü rgen; Useinov, N. Kh.; Tagirov, L. R.

2011-01-01

We present a theoretical approach to calculate the spin-dependent current and tunnel magnetoresistance (TMR) in a double-barrier magnetic tunnel junction (DMTJ), in which the magnetization of the middle ferromagnetic metal layer can be aligned parallel or antiparallel in relation to the fixed magnetizations of the left and right ferromagnetic electrodes. The electron transport through the DMTJ is considered as a three-dimensional problem, taking into account all transmitting electron trajectories as well as the spin-dependent momentum conservation law. The dependence of the transmission coefficient and spin-polarized currents on the applied voltage is derived as an exact solution to the quantum-mechanical problem for the spin-polarized transport. In the range of the developed physical model, the resonant tunneling, nonresonant tunneling, and enhanced spin filtering can be explained; the simulation results are in good agreement with experimental data.

The Kapsiki of the Mandara Hills

NARCIS (Netherlands)

Beek, van W.E.A.

1987-01-01

The Kapsiki of Cameroon and the Higi of Nigeria are two tribes from the Mandara hills area of central and western Africa. Though they form one coherent group of villages, they are usually considered as two separate ethnic units. The author normally uses the term Kapsiki for both. Based on fieldwork

77 FR 2128 - Southwest Pennsylvania Railroad Company-Acquisition Exemption-Laurel Hill Development Corporation

Science.gov (United States)

2012-01-13

... DEPARTMENT OF TRANSPORTATION Surface Transportation Board [Docket No. FD 35584] Southwest Pennsylvania Railroad Company--Acquisition Exemption-- Laurel Hill Development Corporation Southwest... 49 CFR 1150.41 to acquire a number of rail lines now owned by Laurel Hill Development Corporation...

Investigation of periodic systems by means of the generalized Hill method

International Nuclear Information System (INIS)

Baitin, A.V.; Ivanov, A.A.

1994-01-01

We propose the new method of investigation of infinite periodic determination which is a generalized Hill method. This method has been used for finding of the characteristic value for the Hill equation. finding the band structure of the one-dimensional periodic and obtaining of the dispersion equation for the electromagnetic wave propagation in the waveguide by plasma arbitrary periodic density modulation by plasma arbitrary periodic density modulation

Quantum size effects on spin-tunneling time in a magnetic resonant tunneling diode

OpenAIRE

Saffarzadeh, Alireza; Daqiq, Reza

2009-01-01

We study theoretically the quantum size effects of a magnetic resonant tunneling diode (RTD) with a (Zn,Mn)Se dilute magnetic semiconductor layer on the spin-tunneling time and the spin polarization of the electrons. The results show that the spin-tunneling times may oscillate and a great difference between the tunneling time of the electrons with opposite spin directions can be obtained depending on the system parameters. We also study the effect of structural asymmetry which is related to t...

77 FR 33560 - Southwest Pennsylvania Railroad Company-Acquisition Exemption-Laurel Hill Development Corporation

Science.gov (United States)

2012-06-06

... Pennsylvania Railroad Company--Acquisition Exemption-- Laurel Hill Development Corporation Southwest... 49 CFR 1150.41 to acquire a 0.66-mile line of railroad owned by Laurel Hill Development Corporation... rail line. Most recently, in Southwest Pennsylvania Railroad Company--Acquisition Exemption--Laurel...

Evidence to the Marley Hill Public Inquiry

Energy Technology Data Exchange (ETDEWEB)

Wilson, G.K. (Council for the Protection of Rural England (UK). Durham and Teesdale Branch)

1989-11-01

George Kenneth Wilson, a retired power station enginer, and holder of such offices as Vice-Chairman of the CPRE Durham and Teesdale Branch, Secretary of the Derwent Valley Protection Society and an officer of the Opencast Mining Intelligence Group, presents reasons for dismissing the appeal for opencast mining at the Marley Hill site in the NE of England saying that the Mineral Planning Guidance Note, MPG3 seemed to be repeating mistakes inherent in the previous 'Plan for coal'. He considers that the application cannot be justified on the grounds of demand or forecast market trends. The type of coal is unsuitable for local power station boilers. The working of the site would destroy a large area of pleasant countryside. The standard of restoration of the 32 sites surrounding Marley Hill is in his opinion very poor.

Early History of Heavy Isotope Research at Berkeley

Energy Technology Data Exchange (ETDEWEB)

Glenn T. Seaborg

1976-06-01

I have had the idea for some time that it would be interesting and worthwhile to put together an account of the early work on heavy isotopes at Berkeley. Of a special interest is the discovery of plutonium (atomic number 94) and the isotope U{sup 233}, and the demonstration of their fission with slow neutrons. This work served as a prelude to the subsequent Plutonium Project (Metallurgical Project) centered at the University of Chicago, in connection with which I have also had the idea of putting together a history of the work of my chemistry group. I have decided that it would be an interesting challenge to write this account on a day-to-day basis in a style that would be consistent with the entries having been written at the end of each day. The aim would be to make this history as accurate as possible by going back to the original records and using them with meticulous care.

Spin-Off Successes of SETI Research at Berkeley

Science.gov (United States)

Douglas, K. A.; Anderson, D. P.; Bankay, R.; Chen, H.; Cobb, J.; Korpela, E. J.; Lebofsky, M.; Parsons, A.; von Korff, J.; Werthimer, D.

2009-12-01

Our group contributes to the Search for Extra-Terrestrial Intelligence (SETI) by developing and using world-class signal processing computers to analyze data collected on the Arecibo telescope. Although no patterned signal of extra-terrestrial origin has yet been detected, and the immediate prospects for making such a detection are highly uncertain, the SETI@home project has nonetheless proven the value of pursuing such research through its impact on the fields of distributed computing, real-time signal processing, and radio astronomy. The SETI@home project has spun off the Center for Astronomy Signal Processing and Electronics Research (CASPER) and the Berkeley Open Infrastructure for Networked Computing (BOINC), both of which are responsible for catalyzing a smorgasbord of new research in scientific disciplines in countries around the world. Futhermore, the data collected and archived for the SETI@home project is proving valuable in data-mining experiments for mapping neutral galatic hydrogen and for detecting black-hole evaporation.

Optimizing Excited-State Electronic-Structure Codes for Intel Knights Landing: A Case Study on the BerkeleyGW Software

Energy Technology Data Exchange (ETDEWEB)

Deslippe, Jack; da Jornada, Felipe H.; Vigil-Fowler, Derek; Barnes, Taylor; Wichmann, Nathan; Raman, Karthik; Sasanka, Ruchira; Louie, Steven G.

2016-10-06

We profile and optimize calculations performed with the BerkeleyGW code on the Xeon-Phi architecture. BerkeleyGW depends both on hand-tuned critical kernels as well as on BLAS and FFT libraries. We describe the optimization process and performance improvements achieved. We discuss a layered parallelization strategy to take advantage of vector, thread and node-level parallelism. We discuss locality changes (including the consequence of the lack of L3 cache) and effective use of the on-package high-bandwidth memory. We show preliminary results on Knights-Landing including a roofline study of code performance before and after a number of optimizations. We find that the GW method is particularly well-suited for many-core architectures due to the ability to exploit a large amount of parallelism over plane-wave components, band-pairs, and frequencies.

Influence of trap-assisted tunneling on trap-assisted tunneling current in double gate tunnel field-effect transistor

Science.gov (United States)

Zhi, Jiang; Yi-Qi, Zhuang; Cong, Li; Ping, Wang; Yu-Qi, Liu

2016-02-01

Trap-assisted tunneling (TAT) has attracted more and more attention, because it seriously affects the sub-threshold characteristic of tunnel field-effect transistor (TFET). In this paper, we assess subthreshold performance of double gate TFET (DG-TFET) through a band-to-band tunneling (BTBT) model, including phonon-assisted scattering and acoustic surface phonons scattering. Interface state density profile (Dit) and the trap level are included in the simulation to analyze their effects on TAT current and the mechanism of gate leakage current. Project supported by the National Natural Science Foundation of China (Grant Nos. 61574109 and 61204092).

Study of tunneling transport in Si-based tunnel field-effect transistors with ON current enhancement utilizing isoelectronic trap

Science.gov (United States)

Mori, Takahiro; Morita, Yukinori; Miyata, Noriyuki; Migita, Shinji; Fukuda, Koichi; Mizubayashi, Wataru; Masahara, Meishoku; Yasuda, Tetsuji; Ota, Hiroyuki

2015-02-01

The temperature dependence of the tunneling transport characteristics of Si diodes with an isoelectronic impurity has been investigated in order to clarify the mechanism of the ON-current enhancement in Si-based tunnel field-effect transistors (TFETs) utilizing an isoelectronic trap (IET). The Al-N complex impurity was utilized for IET formation. We observed three types of tunneling current components in the diodes: indirect band-to-band tunneling (BTBT), trap-assisted tunneling (TAT), and thermally inactive tunneling. The indirect BTBT and TAT current components can be distinguished with the plot described in this paper. The thermally inactive tunneling current probably originated from tunneling consisting of two paths: tunneling between the valence band and the IET trap and tunneling between the IET trap and the conduction band. The probability of thermally inactive tunneling with the Al-N IET state is higher than the others. Utilization of the thermally inactive tunneling current has a significant effect in enhancing the driving current of Si-based TFETs.

Electrical installations of the Channel tunnel; Installations electriques du Tunnel sous la Manche

Energy Technology Data Exchange (ETDEWEB)

Kersabiec, G. de [Eurotunnel, Folkestone (United Kingdom)

2002-08-01

Like an underground factory, the railway and auxiliary equipments of the Channel tunnel between France and UK, need a reliable and redundant power supply with a high quality maintenance. This article presents: the design criteria of the power distribution systems, the installation itself and the organisation of its exploitation: 1 - transportation system of the Channel tunnel (loads to supply, exploitation imperatives, fundamental criteria); 2 - external power sources (connection to the UK and French grids, values used by the national grids); 3 - exploitation criteria, tunnel design; 4 - description (main UK and French power stations, 25 kV traction network, 21 kV distribution network, tunnels, lighting in railway tunnels, supply of terminals, earthing network); 5 - exploitation; 6 - maintenance and quality. (J.S.)

Heavy-Atom Tunneling Calculations in Thirteen Organic Reactions: Tunneling Contributions are Substantial, and Bell's Formula Closely Approximates Multidimensional Tunneling at ≥250 K.

Science.gov (United States)

Doubleday, Charles; Armas, Randy; Walker, Dana; Cosgriff, Christopher V; Greer, Edyta M

2017-10-09

Multidimensional tunneling calculations are carried out for 13 reactions, to test the scope of heavy-atom tunneling in organic chemistry, and to check the accuracy of one-dimensional tunneling models. The reactions include pericyclic, cycloaromatization, radical cyclization and ring opening, and S N 2. When compared at the temperatures that give the same effective rate constant of 3×10 -5  s -1 , tunneling accounts for 25-95 % of the rate in 8 of the 13 reactions. Values of transmission coefficients predicted by Bell's formula, κ Bell  , agree well with multidimensional tunneling (canonical variational transition state theory with small curvature tunneling), κ SCT . Mean unsigned deviations of κ Bell vs. κ SCT are 0.08, 0.04, 0.02 at 250, 300 and 400 K. This suggests that κ Bell is a useful first choice for predicting transmission coefficients in heavy-atom tunnelling. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hill functions for stochastic gene regulatory networks from master equations with split nodes and time-scale separation

Science.gov (United States)

Lipan, Ovidiu; Ferwerda, Cameron

2018-02-01

The deterministic Hill function depends only on the average values of molecule numbers. To account for the fluctuations in the molecule numbers, the argument of the Hill function needs to contain the means, the standard deviations, and the correlations. Here we present a method that allows for stochastic Hill functions to be constructed from the dynamical evolution of stochastic biocircuits with specific topologies. These stochastic Hill functions are presented in a closed analytical form so that they can be easily incorporated in models for large genetic regulatory networks. Using a repressive biocircuit as an example, we show by Monte Carlo simulations that the traditional deterministic Hill function inaccurately predicts time of repression by an order of two magnitudes. However, the stochastic Hill function was able to capture the fluctuations and thus accurately predicted the time of repression.

Penerapan Metode Hill Climbing Pada Sistem Informasi Geografis Untuk Mencari Lintasan Terpendek

Directory of Open Access Journals (Sweden)

Eka Vickraien Dangkua

2016-04-01

Full Text Available Heuristic search methods is one of the methods commonly in use in finding the shortest path, one of which, namely the methods Hill Climbing process where testing is done using heuristic functions. Problems generally encountered is the shortest path search to solve the problem of distance can be changed into a graph structure, where the point of declaring the city and the State line that connects the two cities. From the logic so that it can locate destinations and save on travel costs. The hallmarks of this algorithm are all possible solutions will have then checked one by one from the left side, so it will be obtained solutions with optimal results. On a Hill Climbing method according to case using geographic information systems as a tool in making a decision, by way of collect, examine, and analyze information related to digital map. with a combination of Hill Climbing method and geographic information systems can result in an application that is certainly feasible for use in the search path problems.   Keywords: Hill Climbin method; digital map; Geographic Information Systems

Macroscopic quantum tunneling in Josephson tunnel junctions and Coulomb blockade in single small tunnel junctions

International Nuclear Information System (INIS)

Cleland, A.N.

1991-01-01

Experiments investigated the process of macroscopic quantum tunneling in a moderately-damped, resistively shunted, Josephson junction are described, followed by a discussion of experiments performed on very-small-capacitance normal-metal tunnel junctions. The experiments on the resistively-shunted Josephson junction were designed to investigate a quantum process, that of the tunneling of the Josephson-phase variable under a potential barrier, in a system in which dissipation plays a major role in the dynamics of motion. All the parameters of the junction were measured using the classical phenomena of thermal activation and resonant activation. Theoretical predictions are compared with the experimental results, showing good agreement with no adjustable parameters. The experiments on small-capacitance tunnel junctions extend the measurements on the large-area Josephson junctions from the region in which the phase variable has a fairly well-defined value, i.e. its wave function has a narrow width, to the region where its value is almost completely unknown. The charge on the junction becomes well-defined and is predicted to quantize the current through the junction, giving rise to the Coulomb blockade at low bias

Water quality impacts from mining in the Black Hills, South Dakota, USA

International Nuclear Information System (INIS)

Rahn, P.H.; Davis, A.D.; Webb, C.J.; Nichols, A.D.

1996-01-01

The focus of this research was to determine if abandoned mines constitute a major environmental hazard in the Black Hills. Many abandoned gold mines in the Black Hills contribute acid and heavy metals to streams. In some areas of sulfide mineralization local impacts are severe, but in most areas the impacts are small because most ore deposits consist of small quartz veins with few sulfides. Pegmatite mines appear to have negligible effects on water due to the insoluble nature of pegmatite minerals. Uranium mines in the southern Black Hills contribute some radioactivity to surface water, but he impact is limited because of the dry climate and lack of runoff in that area. 26 refs

Tunneling rates in electron transport through double-barrier molecular junctions in a scanning tunneling microscope.

Science.gov (United States)

Nazin, G V; Wu, S W; Ho, W

2005-06-21

The scanning tunneling microscope enables atomic-scale measurements of electron transport through individual molecules. Copper phthalocyanine and magnesium porphine molecules adsorbed on a thin oxide film grown on the NiAl(110) surface were probed. The single-molecule junctions contained two tunneling barriers, vacuum gap, and oxide film. Differential conductance spectroscopy shows that electron transport occurs via vibronic states of the molecules. The intensity of spectral peaks corresponding to the individual vibronic states depends on the relative electron tunneling rates through the two barriers of the junction, as found by varying the vacuum gap tunneling rate by changing the height of the scanning tunneling microscope tip above the molecule. A simple, sequential tunneling model explains the observed trends.

BErkeley Atmospheric CO2 Network (BEACON) - Bringing Measurements of CO2 Emissions to a School Near You

Science.gov (United States)

Teige, V. E.; Havel, E.; Patt, C.; Heber, E.; Cohen, R. C.

2011-12-01

The University of California at Berkeley in collaboration with the Chabot Space and Science Center describe a set of educational programs, workshops, and exhibits based on a multi-node greenhouse gas and air quality monitoring network being deployed over Oakland, California. Examining raw numerical data using highly engaging and effective geo-data visualization tools like Google Earth can make the science come alive for students, and provide a hook for drawing them into deeper investigations. The Climate Science Investigations teacher workshop at the Chabot Space and Science Center will make use of Google Earth, Excel, and other geo-data visualization tools to step students through the process from data acquisition to discovery. Using multiple data sources, including output from the BErkeley Atmospheric CO2 Network (BEACON) project, participants will be encouraged to explore a variety of different modes of data display toward producing a unique, and ideally insightful, illumination of the data.

Vacuum phonon tunneling.

Science.gov (United States)

Altfeder, Igor; Voevodin, Andrey A; Roy, Ajit K

2010-10-15

Field-induced phonon tunneling, a previously unknown mechanism of interfacial thermal transport, has been revealed by ultrahigh vacuum inelastic scanning tunneling microscopy (STM). Using thermally broadened Fermi-Dirac distribution in the STM tip as in situ atomic-scale thermometer we found that thermal vibrations of the last tip atom are effectively transmitted to sample surface despite few angstroms wide vacuum gap. We show that phonon tunneling is driven by interfacial electric field and thermally vibrating image charges, and its rate is enhanced by surface electron-phonon interaction.

Breaking through the tranfer tunnel

CERN Document Server

Laurent Guiraud

2001-01-01

This image shows the tunnel boring machine breaking through the transfer tunnel into the LHC tunnel. Proton beams will be transferred from the SPS pre-accelerator to the LHC at 450 GeV through two specially constructed transfer tunnels. From left to right: LHC Project Director, Lyn Evans; CERN Director-General (at the time), Luciano Maiani, and Director for Accelerators, Kurt Hubner.

New Tunneling Features in Polar III-Nitride Resonant Tunneling Diodes

Directory of Open Access Journals (Sweden)

Jimy Encomendero

2017-10-01

Full Text Available For the past two decades, repeatable resonant tunneling transport of electrons in III-nitride double barrier heterostructures has remained elusive at room temperature. In this work we theoretically and experimentally study III-nitride double-barrier resonant tunneling diodes (RTDs, the quantum transport characteristics of which exhibit new features that are unexplainable using existing semiconductor theory. The repeatable and robust resonant transport in our devices enables us to track the origin of these features to the broken inversion symmetry in the uniaxial crystal structure, which generates built-in spontaneous and piezoelectric polarization fields. Resonant tunneling transport enabled by the ground state as well as by the first excited state is demonstrated for the first time over a wide temperature window in planar III-nitride RTDs. An analytical transport model for polar resonant tunneling heterostructures is introduced for the first time, showing a good quantitative agreement with experimental data. From this model we realize that tunneling transport is an extremely sensitive measure of the built-in polarization fields. Since such electric fields play a crucial role in the design of electronic and photonic devices, but are difficult to measure, our work provides a completely new method to accurately determine their magnitude for the entire class of polar heterostructures.

Sharing the Gift of Jazz: An Interview with Willie L. Hill Jr.

Science.gov (United States)

Howe, Brad

2011-01-01

This article presents an interview with Willie L. Hill Jr., founder and director of the Society for Jazz Education. Currently a professor of music education at the University of Massachusetts-Amherst and the director of the UMass Fine Arts Center, Hill has served as director of education for the Thelonious Monk Institute of Jazz. He is a past…

Theoretical consideration of spin-polarized resonant tunneling in magnetic tunnel junctions

International Nuclear Information System (INIS)

Mu Haifeng; Zhu Zhengang; Zheng Qingrong; Jin Biao; Wang Zhengchuan; Su Gang

2004-01-01

A recent elegant experimental realization [S. Yuasa et al., Science 297 (2002) 234] of the spin-polarized resonant tunneling in magnetic tunnel junctions is interpreted in terms of a two-band model. It is shown that the tunnel magnetoresistance (TMR) decays oscillatorily with the thickness of the normal metal (NM) layer, being fairly in agreement with the experimental observation. The tunnel conductance is found to decay with slight oscillations with the increase of the NM layer thickness, which is also well consistent with the experiment. In addition, when the magnetizations of both ferromagnet electrodes are not collinearly aligned, TMR is found to exhibit sharp resonant peaks at some particular thickness of the NM layer. The peaked TMR obeys nicely a Gaussian distribution against the relative orientation of the magnetizations

A tunnel runs through it: an inside view of the Tualatin Mountains, Oregon

Science.gov (United States)

Walsh, Ken; Peterson, Gary L.; Beeson, Marvin H.; Wells, Ray E.; Fleck, Robert J.; Evarts, Russell C.; Duvall, Alison; Blakely, Richard J.; Burns, Scott

2011-01-01

The Tualatin Mountains form a northwest-striking ridge about 350 m high that separates Portland, Oregon, from the cities of the Tualatin Valley to the west. Known informally as the Portland Hills, the ridge is a late Cenozoic anticline, bounded by reverse faults that dip toward the anticlinal axis. The anticline is a broad, open fold consisting chiefly of Miocene Columbia River Basalt Group, with remnants of Miocene-Pliocene Troutdale Formation and Pleistocene basalt of the Boring Volcanic Field on the flanks of the anticline. Anticlinal structures similar to the Tualatin Mountains are characteristic of the northern Willamette Valley, where the structures accommodate margin-parallel shortening of the Cascadia fore arc. Global Positioning System (GPS) results indicate that the shortening is due to the northward motion of Oregon at several millimeters per year with respect to stable North America. Some of the uplifts may contain active faults, but the structures are poorly exposed and are overlain by thick Pleistocene loess and Missoula flood deposits. Between 1993 and 1998, construction of the 3-mile-long (4500-m-long) TriMet MAX Light Rail tunnel through the Tualatin Mountains provided an unusual opportunity to investigate the geological structure and history of the Tualatin Mountains. This report is a collaborative effort among the tunnel geologists and the U.S. Geological Survey (USGS) to document the geologic story and quantify late Cenozoic and Quaternary deformation rates of the Tualatin Mountains.

Histological Observation of Regions around Bone Tunnels after Compression of the Bone Tunnel Wall in Ligament Reconstruction

International Nuclear Information System (INIS)

Maeda, Shintaro; Ishikawa, Hiroki; Tanigawa, Naoaki; Miyazaki, Kyosuke; Shioda, Seiji

2012-01-01

The objectives of this study were to investigate the time-course of influence of compression of bone tunnel wall in ligament reconstruction on tissue around the bone tunnel and to histologically examine the mechanism of preventing the complication of bone tunnel dilation, using rabbit tibia. A model in which the femoral origin of the extensor digitorum longus tendon was cut and inserted into a bone tunnel made proximal to the tibia was prepared in the bilateral hind legs of 20 Japanese white rabbits. In each animal, a tunnel was made using a drill only in the right leg, while an undersized bone tunnel was made by drilling and then dilated by compression using a dilator to the same tunnel size as that in the right leg. Animals were sacrificed at 0, 2, 4, 8 and 12 weeks after surgery (4 animals at each time point). Observation of bone tunnels by X-ray radiography showed osteosclerosis in the 2- and 4-week dilation groups. Osteosclerosis appeared as white lines around the bone tunnel on X-ray radiography. This suggests that dilation promotes callus formation in the bone tunnel wall and prevents the complication of bone tunnel enlargement after ligament reconstruction

Mammals of Kalimpong Hills, Darjeeling District, West Bengal, India

Directory of Open Access Journals (Sweden)

J.K. Mallick

2012-10-01

Full Text Available Neora Valley National Park (NVNP in the Kalimpong Hills, Darjeeling District, having a wide range of altitudinal variations (183-3,200 m and climatic conditions and forming an ecological trijunction with Sikkim and Bhutan, is the last virgin wilderness in West Bengal. It is a global hotspot for the unique ecosystem, where tropical, sub-tropical, temperate and sub-temperate forests represent a wealth of biodiversity including many threatened and rare mammals. It is the prime habitat of Ailurus fulgens (estimated population 28-32, Neofelis nebulosa (population unassessed, Ursus thibetanus (18, Bos gaurus (81, Hemitragus jemlahicus (32, Naemorhedus goral (73, Capricornis sumatraensis (89, Rusa unicolor (286, Muntiacus vaginalis (590 and Sus scrofa (615. Discovery of Panthera tigris (20 in 1998 prompted the forest department to include NVNP as a sensitive wildlife zone. Many authors recorded the mammalian diversity in Darjeeling District since the mid-nineteenth century, but most of them referred to the Darjeeling Hills. The documentations on Kalimpong Hills are scarce because of the dense canopy, thick undergrowth and inaccessible terrain, particularly in the pristine forests of Neora Valley. Consequently, a comprehensive compendium of the mammals in this region was not prepared. A study was undertaken in 2008-2009 with a view to bridging this knowledge-gap and presenting an updated account of the mammalian species in this new short-listed World Heritage Site and surrounding forests of the Kalimpong Hills based on literature review, questionnaire survey, direct sighting and indirect evidences. During June-October 1916, N.A. Baptista recorded 29 mammalian species (22 genera out of 563 specimens collected, from the region. The present study registered 99 species (68 genera after 94 years.

Micro-topography showing the landslide-origin of the Marumori hill, Matsukawa geothermal field Iwate Prefecture, Japan

Energy Technology Data Exchange (ETDEWEB)

Hashimoto, Tomomasa; Ikeda, Kazuo; Sumi, Seiai

1988-07-27

The Marumori Hill in the Matsukawa geothermal field has been previously considered to be a central cone or a lava dome in a caldera. Airphotogeological study, topographical surveying, and trenching are carried out in order to clarify the origin of the hill. Fifty six topographic linearments trending NE-SW direction distributed parallelly were detected on the top area and the northern flank of the hill. This linearment swarm is composed of the alternated small ranges and valleys with asymmetric profiles similar to cuesta topography. These topographic features are considered to be formed under the tensional stress field trending NW-SE direction on the surface of a landslide block. The hill is inferred to be not a lava dome but a landslide block which slide down from the steep scarp north and west of the hill. The age of the landslide is dated back to be older than 2400 years B.P. according to 14C age of the humic strata covering the hill. (7 figs, 1 tab, 14 refs)

Tunnel fire testing and modeling the Morgex North tunnel experiment

CERN Document Server

Borghetti, Fabio; Gandini, Paolo; Frassoldati, Alessio; Tavelli, Silvia

2017-01-01

This book aims to cast light on all aspects of tunnel fires, based on experimental activities and theoretical and computational fluid dynamics (CFD) analyses. In particular, the authors describe a transient full-scale fire test (~15 MW), explaining how they designed and performed the experimental activity inside the Morgex North tunnel in Italy. The entire organization of the experiment is described, from preliminary evaluations to the solutions found for management of operational difficulties and safety issues. This fire test allowed the collection of different measurements (temperature, air velocity, smoke composition, pollutant species) useful for validating and improving CFD codes and for testing the real behavior of the tunnel and its safety systems during a diesel oil fire with a significant heat release rate. Finally, the fire dynamics are compared with empirical correlations, CFD simulations, and literature measurements obtained in other similar tunnel fire tests. This book will be of interest to all ...

Optimization of a tunneling barrier in magnetic tunneling junction by tilted-plasma oxidation

International Nuclear Information System (INIS)

Nam, C.H.; Shim, Heejae; Kim, K.S.; Cho, B.K.

2004-01-01

Oxidation of an AlO x insulating barrier in a magnetic tunneling junction (MTJ) was carried out by a tilted-plasma oxidation method. It was found that the tilted-plasma oxidation induced a gradual change in the extent of oxidation of an insulating layer, which consequently led to a gradual change in the tunneling magnetoresistance (TMR) and specific junction resistance (RA) of the MTJ. We found a linear relation in the TMR versus RA curve with positive and negative slopes for less- and overoxidized junctions, respectively, and a parabolic relation for optimally oxidized junctions. The crossover in the TMR versus RA curves provides an effective and useful way to optimize (and monitor) the oxidation condition of a tunneling barrier in MTJs especially of a tunneling barrier less than 10 A thick. The tunneling junctions were also investigated after thermal annealing at various temperatures. The observations after thermal annealing were found to be consistent with transmission electrons microscopy images and a scenario of the partial formation of an additional ultrathin tunneling barrier at the top surface of the bottom magnetic layer

"Beverly Hills 90210" : kes mida teeb / Tiina Lepiste

Index Scriptorium Estoniae

Lepiste, Tiina

2003-01-01

Aaron Spellingu produtseeritud ja 2000. aastal lõpetatud menuseriaalis "Beverly Hills 90210" osalenud näitlejate edaspidisest elust seoses plaaniga teha täispikk mängufilm "10 Year High School Reunion"

Radioactive and mixed waste management plan for the Lawrence Berkeley Laboratory Hazardous Waste Handling Facility

International Nuclear Information System (INIS)

1995-01-01

This Radioactive and Mixed Waste Management Plan for the Hazardous Waste Handling Facility at Lawrence Berkeley Laboratory is written to meet the requirements for an annual report of radioactive and mixed waste management activities outlined in DOE Order 5820.2A. Radioactive and mixed waste management activities during FY 1994 listed here include principal regulatory and environmental issues and the degree to which planned activities were accomplished

Quantum mechanical tunneling in chemical physics

CERN Document Server

Nakamura, Hiroki

2016-01-01

Quantum mechanical tunneling plays important roles in a wide range of natural sciences, from nuclear and solid-state physics to proton transfer and chemical reactions in chemistry and biology. Responding to the need for further understanding of multidimensional tunneling, the authors have recently developed practical methods that can be applied to multidimensional systems. Quantum Mechanical Tunneling in Chemical Physics presents basic theories, as well as original ones developed by the authors. It also provides methodologies and numerical applications to real molecular systems. The book offers information so readers can understand the basic concepts and dynamics of multidimensional tunneling phenomena and use the described methods for various molecular spectroscopy and chemical dynamics problems. The text focuses on three tunneling phenomena: (1) energy splitting, or tunneling splitting, in symmetric double well potential, (2) decay of metastable state through tunneling, and (3) tunneling effects in chemical...

Tunneling into quantum wires: regularization of the tunneling Hamiltonian and consistency between free and bosonized fermions

OpenAIRE

Filippone, Michele; Brouwer, Piet

2016-01-01

Tunneling between a point contact and a one-dimensional wire is usually described with the help of a tunneling Hamiltonian that contains a delta function in position space. Whereas the leading order contribution to the tunneling current is independent of the way this delta function is regularized, higher-order corrections with respect to the tunneling amplitude are known to depend on the regularization. Instead of regularizing the delta function in the tunneling Hamiltonian, one may also obta...

Tunnelling of a molecule

International Nuclear Information System (INIS)

Jarvis, P.D.; Bulte, D.P.

1998-01-01

A quantum-mechanical description of tunnelling is presented for a one-dimensional system with internal oscillator degrees of freedom. The 'charged diatomic molecule' is frustrated on encountering a barrier potential by its centre of charge not being coincident with its centre of mass, resulting in transitions amongst internal states. In an adiabatic limit, the tunnelling of semiclassical coherent-like oscillator states is shown to exhibit the Hartman and Bueuttiker-Landauer times t H and t BL , with the time dependence of the coherent state parameter for the tunnelled state given by α(t) = α e -iω(t+Δt) , Δt = t H - it BL . A perturbation formalism is developed, whereby the exact transfer matrix can be expanded to any desired accuracy in a suitable limit. An 'intrinsic' time, based on the oscillator transition rate during tunnelling, transmission or reflection, is introduced. In simple situations the resulting intrinsic tunnelling time is shown to vanish to lowest order. In the general case a particular (nonzero) parametrisation is inferred, and its properties discussed in comparison with the literature on tunnelling times for both wavepackets and internal clocks. Copyright (1998) CSIRO Australia

Influence of quasiparticle multi-tunneling on the energy flow through the superconducting tunnel junction

International Nuclear Information System (INIS)

Samedov, V. V.; Tulinov, B. M.

2011-01-01

Superconducting tunnel junction (STJ) detector consists of two layers of superconducting material separated by thin insulating barrier. An incident particle produces in superconductor excess nonequilibrium quasiparticles. Each quasiparticle in superconductor should be considered as quantum superposition of electron-like and hole-like excitations. This duality nature of quasiparticle leads to the effect of multi-tunneling. Quasiparticle starts to tunnel back and forth through the insulating barrier. After tunneling from biased electrode quasiparticle loses its energy via phonon emission. Eventually, the energy that equals to the difference in quasiparticle energy between two electrodes is deposited in the signal electrode. Because of the process of multi-tunneling, one quasiparticle can deposit energy more than once. In this work, the theory of branching cascade processes was applied to the process of energy deposition caused by the quasiparticle multi-tunneling. The formulae for the mean value and variance of the energy transferred by one quasiparticle into heat were derived. (authors)

Life sciences: Lawrence Berkeley Laboratory, 1988

Energy Technology Data Exchange (ETDEWEB)

1989-07-01

Life Sciences Research at LBL has both a long history and a new visibility. The physics technologies pioneered in the days of Ernest O. Lawrence found almost immediate application in the medical research conducted by Ernest's brother, John Lawrence. And the tradition of nuclear medicine continues today, largely uninterrupted for more than 50 years. Until recently, though, life sciences research has been a secondary force at the Lawrence Berkeley Laboratory (LBL). Today, a true multi-program laboratory has emerged, in which the life sciences participate as a full partner. The LBL Human Genome Center is a contribution to the growing international effort to map the human genome. Its achievements represent LBL divisions, including Engineering, Materials and Chemical Sciences, and Information and Computing Sciences, along with Cell and Molecular Biology and Chemical Biodynamics. The Advanced Light Source Life Sciences Center will comprise not only beamlines and experimental end stations, but also supporting laboratories and office space for scientists from across the US. This effort reflects a confluence of scientific disciplines --- this time represented by individuals from the life sciences divisions and by engineers and physicists associated with the Advanced Light Source project. And finally, this report itself, the first summarizing the efforts of all four life sciences divisions, suggests a new spirit of cooperation. 30 figs.

Exploratory Research and Development Fund, FY 1990. Report on Lawrence Berkeley Laboratory

Energy Technology Data Exchange (ETDEWEB)

1992-05-01

The Lawrence Berkeley Laboratory Exploratory R&D Fund FY 1990 report is compiled from annual reports submitted by principal investigators following the close of the fiscal year. This report describes the projects supported and summarizes their accomplishments. It constitutes a part of an Exploratory R&D Fund (ERF) planning and documentation process that includes an annual planning cycle, projection selection, implementation, and review. The research areas covered in this report are: Accelerator and fusion research; applied science; cell and molecular biology; chemical biodynamics; chemical sciences; earth sciences; engineering; information and computing sciences; materials sciences; nuclear science; physics and research medicine and radiation biophysics.

Enhanced MRI in carpal tunnel syndrome

International Nuclear Information System (INIS)

Hayakawa, Katsuhiko; Nakane, Takashi; Kobayashi, Shigeru; Asai, Takahiro; Wada, Kunio; Yoshizawa, Hidezo

1998-01-01

In this study, we performed contrast-enhanced MRI in patients with idiopathic carpal tunnel syndrome and examined the morphologic change in the carpal tunnel. In the transverse section of the opening of carpal tunnel where scaphoid and pisiform bones are figured out, we measured and examined 4 items, viz. the soft carpal tunnel volume, flat rate of median nerve, position of median nerve and thickness of palmer ligaments composing the base of carpal tunnel, with an image analyzer attached to the MRI apparatus. Whereas the average carpal tunnel volume in 12 hands of normal controls was 166.8 mm 2 , that in 74 hands of carpal tunnel syndrome was 207.2 mm 2 , a significant increase compared with the normal controls. The flat rate of median nerve was 46% in the controls, but that was 37.5% in the carpal tunnel syndrome, a significant flattening was noted. We connected the peaks of the scaphoid node and pisiform bone with a line and named it standard line. When we observed the position of median nerve in the carpal tunnel, the nerve in 9 of 12 hands, 75%, lay below the standard line in the controls, but the nerve in 65 of 74 hands, 87.8%, lay above the standard line in the carpal tunnel syndrome, clearly showing that the median nerve had shifted to the palmar side. Regarding these morphologic changes of the carpal tunnel, the internal pressure of the carpal tunnel is considered to be raised with swelling of the soft tissues mainly composing the inside of carpal tunnel, thus the area of cross section of carpal tunnel to be increased, the median nerve to be shifted to the palmar side and the median nerve to be compressed by the transverse carpal ligament at that time. Although we can observe these morphological changes readily in MRI images, these images show only the results of carpal tunnel syndrome after all, and do not specify the direct causes. However, we believe that these facts are important factors in the manifestation of idiopathic carpal tunnel syndrome. (author)

Josephson tunneling and nanosystems

OpenAIRE

Ovchinnikov, Yurii; Kresin, Vladimir

2010-01-01

Josephson tunneling between nanoclusters is analyzed. The discrete nature of the electronic energy spectra, including their shell ordering, is explicitly taken into account. The treatment considers the two distinct cases of resonant and non-resonant tunneling. It is demonstrated that the current density greatly exceeds the value discussed in the conventional theory. Nanoparticles are shown to be promising building blocks for nanomaterials-based tunneling networks.

Probing spin-polarized tunneling at high bias and temperature with a magnetic tunnel transistor

NARCIS (Netherlands)

Park, B.G.; Banerjee, T.; Min, B.C.; Sanderink, Johannes G.M.; Lodder, J.C.; Jansen, R.

2005-01-01

The magnetic tunnel transistor (MTT) is a three terminal hybrid device that consists of a tunnel emitter, a ferromagnetic (FM) base, and a semiconductor collector. In the MTT with a FM emitter and a single FM base, spin-polarized hot electrons are injected into the base by tunneling. After

Control of tunneling in heterostructures

International Nuclear Information System (INIS)

Volokhov, V M; Tovstun, C A; Ivlev, B

2007-01-01

A tunneling current between two rectangular potential wells can be effectively controlled by applying an external ac field. A variation of the ac frequency by 10% may lead to the suppression of the tunneling current by two orders of magnitude, which is a result of quantum interference under the action of the ac field. This effect of destruction of tunneling can be used as a sensitive control of tunneling current across nanosize heterostructures

Review of Barrow Hill: Curse of the Ancient Circle PC Game

OpenAIRE

Michael Charno

2007-01-01

Archaeological video games are few and far between. Internet Archaeology has reviewed a number of archaeologically-based computer applications, but none that in my opinion would fall under the video game category. Barrow Hill: Curse of the ancient circle from Shadow Tor Studios, is a video game…with archaeology in it. It would be a stretch to claim that Barrow Hill is actually an archaeological video game, but it does have an occasionally solid archaeological foundation and back story.

Tunnelling in Soft Soil : Tunnel Boring Machine Operation and Soil Response

NARCIS (Netherlands)

Festa, D.; Broere, W.; Bosch, J.W.

2013-01-01

Constructing tunnels in soft soil with the use of Tunnel Boring Machines may induce settlements including soil movements ahead of the face, soil relaxation into the tail void, possible heave due to grouting, long lasting consolidation processes, and potentially several other mechanisms. A

Structure and evolution of the Horse Heaven Hills in South-Central Washington

International Nuclear Information System (INIS)

Hagood, M.C.

1986-03-01

The purpose of this study is to describe the structure and evolution of the Horse Heaven Hills uplift at its abrupt structural transition. This was achieved by: (1) delineating the structure within the two trends as they approach the intersection; (2) determining the timing and location of uplift within each trend; (3) comparing and contrasting Miocene vertical growth rates along folds within both trends; and (4) imposing constraints for tectonic models that pertain to the genesis of the Horse Heaven Hills uplift. These objectives can only be fulfilled if the stratigraphy of the area is first delineated. Data from this study suggest that tectonic models that directly or indirectly pertain to the origin of the Horse Heaven Hills uplift may be constrained by: (1) the predominance of monoclinal or near-monoclinal fold geometries and reverse faults along both the northwest and northeast trends; (2) preliminary data which suggest clockwise rotation has occurred along folds of both trends; (3) folds along both trends developing simultaneously and at similar rates (at least during Wanapum and Saddle Mountains time); (4) folds along the northwest trend of the Horse Heaven Hills uplift being genetically related to and forming simultaneously with at least certain folds along the Rattlesnake-Wallula structural alignment; (5) the uplift developing simultaneously with the north-northwest-trending Hog Ranch-Naneum Ridge anticline as well as other Yakima folds during at least Columbia River Basalt Group time. It is proposed that folds of both trends of the Horse Heaven Hills uplift were generated by the same tectonic processes

Seismic prediction ahead of tunnel constructions

Science.gov (United States)

Jetschny, S.; Bohlen, T.; Nil, D. D.; Giese, R.

2007-12-01

To increase safety and efficiency of tunnel constructions, online seismic exploration ahead of a tunnel can become a valuable tool. Within the \\it OnSite project founded by the BMBF (German Ministry of Education and Research) within \\it GeoTechnologien a new forward looking seismic imaging technique is developed to e.g. determine weak and water bearing zones ahead of the constructions. Our approach is based on the excitation and registration of \\it tunnel surface waves. These waves are excited at the tunnel face behind the cutter head of a tunnel boring machine and travel into drilling direction. Arriving at the front face they generate body waves (mainly S-waves) propagating further ahead. Reflected S-waves are back- converted into tunnel surface waves. For a theoretical description of the conversion process and for finding optimal acquisition geometries it is of importance to study the propagation characteristics of tunnel surface waves. 3D seismic finite difference modeling and analytic solutions of the wave equation in cylindric coordinates revealed that at higher frequencies, i.e. if the tunnel diameter is significantly larger than the wavelength of S-waves, these surface waves can be regarded as Rayleigh-waves circulating the tunnel. For smaller frequencies, i.e. when the S-wavelength approaches the tunnel diameter, the propagation characteristics of these surface waves are then similar to S- waves. Field measurements performed by the GeoForschungsZentrum Potsdam, Germany at the Gotthard Base Tunnel (Switzerland) show both effects, i.e. the propagation of Rayleigh- and body-wave like waves along the tunnel. To enhance our understanding of the excitation and propagation characteristics of tunnel surface waves the transition of Rayleigh to tube-waves waves is investigated both analytically and by numerical simulations.

Radioactive waste management research at CEGB Berkeley nuclear laboratories

International Nuclear Information System (INIS)

Bradbury, D.

1988-01-01

The CEGB is the major electric utility in the United Kingdom. This paper discusses how, at the research laboratories at Berkeley (BNL), several programs of work are currently taking place in the radioactive waste management area. The theme running through all this work is the safe isolation of radionuclides from the environment. Normally this means disposal of waste in solid form, but it may also be desirable to segregate and release nonradioactive material from the waste to reduce volume or improve the solid waste characteristics (e.g., the release of liquid or gaseous effluents after treatment to convert the radioactivity to solid form). The fuel cycle and radioactive waste section at BNL has a research program into these aspects for wastes arising from the operation or decommissioning of power stations. The work is done both in-house and on contract, with primarily the UKAEA

Gap anisotropy and tunneling currents. [MPS3

DEFF Research Database (Denmark)

Lazarides, N.; Sørensen, Mads Peter

1996-01-01

The tunneling Hamiltonian formalism is applied to calculate the tunnelingcurrents through a small superconducting tunnel junction. The formalism isextended to nonconstant tunneling matrix elements. The electrodes of thejunction are assumed to......The tunneling Hamiltonian formalism is applied to calculate the tunnelingcurrents through a small superconducting tunnel junction. The formalism isextended to nonconstant tunneling matrix elements. The electrodes of thejunction are assumed to...

Public Computer Usage in Chapel Hill Public Library

Data.gov (United States)

Town of Chapel Hill, North Carolina — Data collected November 2014 - May 2016. As of June 2016, this data is no longer collected on a continual basis.This dataset includes frequency and length of use of...

Magnetic Fluxtube Tunneling

Science.gov (United States)

Dahlburg, Russell B.; Antiochos,, Spiro K.; Norton, D.

1996-01-01

We present numerical simulations of the collision and subsequent interaction of two initially orthogonal, twisted, force free field magnetic fluxtubes. The simulations were carried out using a new three dimensional explicit parallelized Fourier collocation algorithm for solving the viscoresistive equations of compressible magnetohydrodynamics. It is found that, under a wide range of conditions, the fluxtubes can 'tunnel' through each other. Two key conditions must be satisfied for tunneling to occur: the magnetic field must be highly twisted with a field line pitch much greater than 1, and the magnetic Lundquist number must be somewhat large, greater than or equal to 2880. This tunneling behavior has not been seen previously in studies of either vortex tube or magnetic fluxtube interactions. An examination of magnetic field lines shows that tunneling is due to a double reconnection mechanism. Initially orthogonal field lines reconnect at two specific locations, exchange interacting sections and 'pass' through each other. The implications of these results for solar and space plasmas are discussed.

Profiles in medical courage: causation and Austin Bradford Hill

Directory of Open Access Journals (Sweden)

Robbins RA

2012-09-01

Full Text Available Austin Bradford Hill was a British epidemiologist and statistician who is best remembered for two landmark pulmonary studies. He was the statistician on the Medical Research Council Streptomycin in Tuberculosis Trial. This is regarded as the first randomized clinical trial. The second was the demonstration of the connection between cigarette smoking and lung cancer. However, Hill’s most lasting contribution may be his establishment of a group of conditions necessary to provide adequate evidence of a causal relationship between an incidence and a consequence, widely known as the Bradford Hill Criteria of Causation. In this profile of medical courage we examine his remarkable background that led to the epidemiological equivalent of Koch’s postulates.

Atomistic modeling trap-assisted tunneling in hole tunnel field effect transistors

Science.gov (United States)

Long, Pengyu; Huang, Jun Z.; Povolotskyi, Michael; Sarangapani, Prasad; Valencia-Zapata, Gustavo A.; Kubis, Tillmann; Rodwell, Mark J. W.; Klimeck, Gerhard

2018-05-01

Tunnel Field Effect Transistors (FETs) have the potential to achieve steep Subthreshold Swing (S.S.) below 60 mV/dec, but their S.S. could be limited by trap-assisted tunneling (TAT) due to interface traps. In this paper, the effect of trap energy and location on OFF-current (IOFF) of tunnel FETs is evaluated systematically using an atomistic trap level representation in a full quantum transport simulation. Trap energy levels close to band edges cause the highest leakage. Wave function penetration into the surrounding oxide increases the TAT current. To estimate the effects of multiple traps, we assume that the traps themselves do not interact with each other and as a whole do not modify the electrostatic potential dramatically. Within that model limitation, this numerical metrology study points to the critical importance of TAT in the IOFF in tunnel FETs. The model shows that for Dit higher than 1012/(cm2 eV) IO F F is critically increased with a degraded IO N/IO F F ratio of the tunnel FET. In order to have an IO N/IO F F ratio higher than 104, the acceptable Dit near Ev should be controlled to no larger than 1012/(cm2 eV) .

Hanoi and the American War: Two International Histories

Directory of Open Access Journals (Sweden)

Geoffrey C. Stewart

2014-03-01

Full Text Available Pierre Asselin, Hanoi’s Road to the Vietnam War, 1954-1965. Berkeley: University of California Press, 2013. 319 pp. $55 (cloth Lien-Hang T. Nguyen, Hanoi’s War: An International History of the War for Peace in Vietnam. Chapel Hill: The University of North Carolina Press, 2012. 444 pp. $34.95 (cloth.

Review of Barrow Hill: Curse of the Ancient Circle PC Game

Directory of Open Access Journals (Sweden)

Michael Charno

2007-01-01

Full Text Available Archaeological video games are few and far between. Internet Archaeology has reviewed a number of archaeologically-based computer applications, but none that in my opinion would fall under the video game category. Barrow Hill: Curse of the ancient circle from Shadow Tor Studios, is a video game…with archaeology in it. It would be a stretch to claim that Barrow Hill is actually an archaeological video game, but it does have an occasionally solid archaeological foundation and back story.

Lowest order in inelastic tunneling approximation : efficient scheme for simulation of inelastic electron tunneling data

NARCIS (Netherlands)

Rossen, E.T.R.; Flipse, C.F.J.; Cerda, J.I.

2013-01-01

We have developed an efficient and accurate formalism which allows the simulation at the ab initio level of inelastic electron tunneling spectroscopy data under a scanning tunneling microscope setup. It exploits fully the tunneling regime by carrying out the structural optimization and vibrational

Scanning tunneling microscopic images and scanning tunneling spectra for coupled rectangular quantum corrals

International Nuclear Information System (INIS)

Mitsuoka, Shigenori; Tamura, Akira

2011-01-01

Assuming that an electron confined by double δ-function barriers lies in a quasi-stationary state, we derived eigenstates and eigenenergies of the electron. Such an electron has a complex eigenenergy, and the imaginary part naturally leads to the lifetime of the electron associated with tunneling through barriers. We applied this point of view to the electron confined in a rectangular quantum corral (QC) on a noble metal surface, and obtained scanning tunneling microscopic images and a scanning tunneling spectrum consistent with experimental ones. We investigated the electron states confined in coupled QCs and obtained the coupled states constructed with bonding and anti-bonding states. Using those energy levels and wavefunctions we specified scanning tunneling microscope (STM) images and scanning tunneling spectra (STS) for the doubly and triply coupled QCs. In addition we pointed out the feature of resonant electron states associated with the same QCs at both ends of the triply coupled QCs.

Berkeley lab checkpoint/restart (BLCR) for Linux clusters

International Nuclear Information System (INIS)

Hargrove, Paul H; Duell, Jason C

2006-01-01

This article describes the motivation, design and implementation of Berkeley Lab Checkpoint/Restart (BLCR), a system-level checkpoint/restart implementation for Linux clusters that targets the space of typical High Performance Computing applications, including MPI. Application-level solutions, including both checkpointing and fault-tolerant algorithms, are recognized as more time and space efficient than system-level checkpoints, which cannot make use of any application-specific knowledge. However, system-level checkpointing allows for preemption, making it suitable for responding to ''fault precursors'' (for instance, elevated error rates from ECC memory or network CRCs, or elevated temperature from sensors). Preemption can also increase the efficiency of batch scheduling; for instance reducing idle cycles (by allowing for shutdown without any queue draining period or reallocation of resources to eliminate idle nodes when better fitting jobs are queued), and reducing the average queued time (by limiting large jobs to running during off-peak hours, without the need to limit the length of such jobs). Each of these potential uses makes BLCR a valuable tool for efficient resource management in Linux clusters

2013 strategic petroleum reserve big hill well integrity grading report.

Energy Technology Data Exchange (ETDEWEB)

Lord, David L.; Roberts, Barry L.; Lord, Anna C. Snider; Bettin, Giorgia; Sobolik, Steven Ronald; Park, Byoung Yoon; Rudeen, David Keith; Eldredge, Lisa; Wynn, Karen; Checkai, Dean; Perry, James Thomas

2014-02-01

This report summarizes the work performed in developing a framework for the prioritization of cavern access wells for remediation and monitoring at the Big Hill Strategic Petroleum Reserve site. This framework was then applied to all 28 wells at the Big Hill site with each well receiving a grade for remediation and monitoring. Numerous factors affecting well integrity were incorporated into the grading framework including casing survey results, cavern pressure history, results from geomechanical simulations, and site geologic factors. The framework was developed in a way as to be applicable to all four of the Strategic Petroleum Reserve sites.

Ivar Giaever, Tunneling, and Superconductors

Science.gov (United States)

dropdown arrow Site Map A-Z Index Menu Synopsis Ivar Giaever, Tunneling, and Superconductors Resources with in Superconductors Measured by Electron Tunneling; Physical Review Letters, Vol. 5 Issue 4: 147 - 148 ; August 15, 1960 Electron Tunneling Between Two Superconductors; Physical Review Letters, Vol. 5 Issue 10

Physics of optimal resonant tunneling

NARCIS (Netherlands)

Racec, P.N.; Stoica, T.; Popescu, C.; Lepsa, M.I.; Roer, van de T.G.

1997-01-01

The optimal resonant tunneling, or the complete tunneling transparence of a biased double-barrier resonant-tunneling (DBRT) structure, is discussed. It is shown that its physics does not rest on the departure from the constant potential within the barriers and well, due to the applied electric

Spin-polarized tunneling with GaAs tips in scanning tunneling microscopy

NARCIS (Netherlands)

Prins, M.W.J.; Jansen, R.; Kempen, van H.

1996-01-01

We describe a model as well as experiments on spin-polarized tunneling with the aid of optical spin orientation. This involves tunnel junctions between a magnetic material and gallium arsenide (GaAs), where the latter is optically excited with circularly polarized light in order to generate

Submucosal tunneling techniques: current perspectives.

Science.gov (United States)

Kobara, Hideki; Mori, Hirohito; Rafiq, Kazi; Fujihara, Shintaro; Nishiyama, Noriko; Ayaki, Maki; Yachida, Tatsuo; Matsunaga, Tae; Tani, Johji; Miyoshi, Hisaaki; Yoneyama, Hirohito; Morishita, Asahiro; Oryu, Makoto; Iwama, Hisakazu; Masaki, Tsutomu

2014-01-01

Advances in endoscopic submucosal dissection include a submucosal tunneling technique, involving the introduction of tunnels into the submucosa. These tunnels permit safer offset entry into the peritoneal cavity for natural orifice transluminal endoscopic surgery. Technical advantages include the visual identification of the layers of the gut, blood vessels, and subepithelial tumors. The creation of a mucosal flap that minimizes air and fluid leakage into the extraluminal cavity can enhance the safety and efficacy of surgery. This submucosal tunneling technique was adapted for esophageal myotomy, culminating in its application to patients with achalasia. This method, known as per oral endoscopic myotomy, has opened up the new discipline of submucosal endoscopic surgery. Other clinical applications of the submucosal tunneling technique include its use in the removal of gastrointestinal subepithelial tumors and endomicroscopy for the diagnosis of functional and motility disorders. This review suggests that the submucosal tunneling technique, involving a mucosal safety flap, can have potential values for future endoscopic developments.

Ultrafast scanning tunneling microscopy

Energy Technology Data Exchange (ETDEWEB)

Botkin, D.A. [California Univ., Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley Lab., CA (United States)

1995-09-01

I have developed an ultrafast scanning tunneling microscope (USTM) based on uniting stroboscopic methods of ultrafast optics and scanned probe microscopy to obtain nanometer spatial resolution and sub-picosecond temporal resolution. USTM increases the achievable time resolution of a STM by more than 6 orders of magnitude; this should enable exploration of mesoscopic and nanometer size systems on time scales corresponding to the period or decay of fundamental excitations. USTM consists of a photoconductive switch with subpicosecond response time in series with the tip of a STM. An optical pulse from a modelocked laser activates the switch to create a gate for the tunneling current, while a second laser pulse on the sample initiates a dynamic process which affects the tunneling current. By sending a large sequence of identical pulse pairs and measuring the average tunnel current as a function of the relative time delay between the pulses in each pair, one can map the time evolution of the surface process. USTM was used to measure the broadband response of the STM`s atomic size tunnel barrier in frequencies from tens to hundreds of GHz. The USTM signal amplitude decays linearly with the tunnel junction conductance, so the spatial resolution of the time-resolved signal is comparable to that of a conventional STM. Geometrical capacitance of the junction does not appear to play an important role in the measurement, but a capacitive effect intimately related to tunneling contributes to the measured signals and may limit the ultimate resolution of the USTM.

The comparison between limited open carpal tunnel release using direct vision and tunneling technique and standard open carpal tunnel release: a randomized controlled trial study.

Science.gov (United States)

Suppaphol, Sorasak; Worathanarat, Patarawan; Kawinwongkovit, Viroj; Pittayawutwinit, Preecha

2012-04-01

To compare the operative outcome of carpal tunnel release between limited open carpal tunnel release using direct vision and tunneling technique (group A) with standard open carpal tunnel release (group B). Twenty-eight patients were enrolled in the present study. A single blind randomized control trial study was conducted to compare the postoperative results between group A and B. The study parameters were Levine's symptom severity and functional score, grip and pinch strength, and average two-point discrimination. The postoperative results between two groups were comparable with no statistical significance. Only grip strength at three months follow up was significantly greater in group A than in group B. The limited open carpal tunnel release in the present study is effective comparable to the standard open carpal tunnel release. The others advantage of this technique are better cosmesis and improvement in grip strength at the three months postoperative period.

13th Australian tunnelling conference. Proceedings

Energy Technology Data Exchange (ETDEWEB)

NONE

2008-07-01

The theme of the conference was 'Engineering in a changing environment'. Topics covered include Australian tunnelling projects, design and development of ground support, tunnelling, international projects, fire and life safety, mining projects, risk management in tunnelling, and tunnel boring machine tunnelling. Papers of particular interest to the coal industry are: improving roadway development in underground coal mine (G. Lewis and G. Gibson), and polymer-based alternative to steel mesh for coal mine strata reinforcement (C. Lukey and others).

Does flexible tunnel drilling affect the femoral tunnel angle measurement after anterior cruciate ligament reconstruction?

Science.gov (United States)

Muller, Bart; Hofbauer, Marcus; Atte, Akere; van Dijk, C Niek; Fu, Freddie H

2015-12-01

To quantify the mean difference in femoral tunnel angle (FTA) as measured on knee radiographs between rigid and flexible tunnel drilling after anatomic anterior cruciate ligament (ACL) reconstruction. Fifty consecutive patients that underwent primary anatomic ACL reconstruction with a single femoral tunnel drilled with a flexible reamer were included in this study. The control group was comprised of 50 patients all of who underwent primary anatomic ACL reconstruction with a single femoral tunnel drilled with a rigid reamer. All femoral tunnels were drilled through a medial portal to ensure anatomic tunnel placement. The FTA was determined from post-operative anterior-to-posterior (AP) radiographs by two independent observers. A 5° difference between the two mean FTA was considered clinically significant. The average FTA, when drilled with a rigid reamer, was 42.0° ± 7.2°. Drilling with a flexible reamer resulted in a mean FTA of 44.7° ± 7.0°. The mean difference of 2.7° was not statistically significant. The intraclass correlation coefficient for inter-tester reliability was 0.895. The FTA can be reliably determined from post-operative AP radiographs and provides a useful and reproducible metric for characterizing femoral tunnel position after both rigid and flexible femoral tunnel drilling. This has implications for post-operative evaluation and preoperative treatment planning for ACL revision surgery. IV.

Solar heating and hot water system installed at Cherry Hill, New Jersey

Science.gov (United States)

1979-01-01

The solar heating and hot water system installed in existing buildings at the Cherry Hill Inn in Cherry Hill, New Jersey is described in detail. The system is expected to furnish 31.5% of the overall heating load and 29.8% of the hot water load. The collectors are liquid evacuated tube type. The storage system is an above ground insulated steel water tank with a capacity of 7,500 gallons.

Derivation of the tunnelling exchange time for the model of trap-assisted tunnelling

International Nuclear Information System (INIS)

Racko, J.; Ballo, P.; Benko, P.; Harmatha, L.; Grmanova, A.; Breza, J.

2014-01-01

We present derivation of the tunnelling exchange times that play the key role in the model of trap assisted tunnelling (TAT) considering the electron and hole exchange processes between the trapping centre lying in the forbidden band of the semiconductor and the conduction band, valence band or a metal. All exchange processes are quantitatively described by respective exchange times. The reciprocal values of these exchange times represent the frequency with which the exchange processes contribute to the probability of occupation of the trap by free charge carriers. The crucial problem in any model of TAT is the calculation of the occupation probability. In our approach this probability is expressed in terms of only thermal and tunnelling exchange times. The concept of tunnelling exchange times presents a dominant contribution to our model of TAT. The new approach allows to simply calculate the probability of occupation of the trapping centre by a free charge carrier and subsequently to get the thermal and tunnelling generation-recombination rates occurring in the continuity equations. This is why the TAT model based on thermal and tunnelling exchange times is suitable for simulating the electrical properties of semiconductor nanostructures in which quantum mechanical phenomena play a key role. (authors)

SCR series switch and impulse crowbar at the Lawrence Berkeley Laboratory for CTR neutral beam source development

International Nuclear Information System (INIS)

Franck, J.V.; Arthur, A.A.; Brusse, L.A.; Low, W.

1977-10-01

The series switch is designed to operate at 120kV and pass 65A for 0.5 sec every 30 sec on the Lawrence Berkeley Laboratory CTR Neutral Beam Source Test Stand IIIB. The series switch consists of 400 individual SCR circuits connected in series and is turned on by a simple system of cascaded pulse transformers with multiple single turn secondaries each driving the individual SCR gates. It is turned off by an SCR impulse crowbar that momentarily shorts the power supply allowing the series switch to recover. The SCR switch has been tested in the impulse crowbar configuration and will reliably commutate up to 90A at 120kV. The series switch and impulse crowbar are now in service in Test Stand IIIB. A series switch and impulse crowbar similar in concept is routinely powering a 10 x 10 cm source at 150kV, 20A, 0.5 sec with a 1% duty cycle on the Lawrence Berkeley Laboratory CTR NSB Test Stand IIIA

Electronic noise of superconducting tunnel junction detectors

International Nuclear Information System (INIS)

Jochum, J.; Kraus, H.; Gutsche, M.; Kemmather, B.; Feilitzsch, F. v.; Moessbauer, R.L.

1994-01-01

The optimal signal to noise ratio for detectors based on superconducting tunnel junctions is calculated and compared for the cases of a detector consisting of one single tunnel junction, as well as of series and of parallel connections of such tunnel junctions. The influence of 1 / f noise and its dependence on the dynamical resistance of tunnel junctions is discussed quantitatively. A single tunnel junction yields the minimum equivalent noise charge. Such a tunnel junction exhibits the best signal to noise ratio if the signal charge is independent of detector size. In case, signal charge increases with detector size, a parallel or a series connection of tunnel junctions would provide the optimum signal to noise ratio. The equivalent noise charge and the respective signal to noise ratio are deduced as functions of tunnel junction parameters such as tunneling time, quasiparticle lifetime, etc. (orig.)

Tunneling of Atoms, Nuclei and Molecules

International Nuclear Information System (INIS)

Bertulani, C.A.

2015-01-01

This is a brief review of few relevant topics on tunneling of composite particles and how the coupling to intrinsic and external degrees of freedom affects tunneling probabilities. I discuss the phenomena of resonant tunneling, different barriers seen by subsystems, damping of resonant tunneling by level bunching and continuum effects due to particle dissociation. (author)

Long-term changes in explosive and effusive behaviour at andesitic arc volcanoes: Chronostratigraphy of the Centre Hills Volcano, Montserrat

Science.gov (United States)

Coussens, Maya; Cassidy, Michael; Watt, Sebastian F. L.; Jutzeler, Martin; Talling, Peter J.; Barfod, Dan; Gernon, Thomas M.; Taylor, Rex; Hatter, Stuart J.; Palmer, Martin R.; Montserrat Volcano Observatory

2017-03-01

Volcanism on Montserrat (Lesser Antilles arc) has migrated southwards since the formation of the Silver Hills 2.5 Ma, and has formed three successively active volcanic centres. The Centre Hills volcano was the focus of volcanism from 1-0.4 Ma, before activity commenced at the currently active Soufrière Hills volcano. The history of activity at these two volcanoes provides an opportunity to investigate the pattern of volcano behaviour on an andesitic arc island over the lifetime of individual volcanoes. Here, we describe the pyroclastic stratigraphy of subaerial exposures around central Montserrat; identifying 11 thick (> 1 m) pumiceous units derived from sustained explosive eruptions of Centre Hills from 0.8-0.4 Ma. Over 10 other, less well- exposed pumiceous units have also been identified. The pumice-rich units are interbedded with andesite lava breccias derived from effusive, dome-forming eruptions of Centre Hills. The stratigraphy indicates that large (up to magnitude 5) explosive eruptions occurred throughout the history of Centre Hills, alongside effusive activity. This behaviour at Centre Hills contrasts with Soufrière Hills, where deposits from sustained explosive eruptions are much less common and restricted to early stages of activity at the volcano, from 175-130 ka. Subsequent eruptions at Soufriere Hills have been dominated by andesitic effusive eruptions. The bulk composition, petrography and mineral chemistry of volcanic rocks from Centre Hills and Soufrière Hills are similar throughout the history of both volcanoes, except for occasional, transient departures to different magma compositions, which mark shifts in vent location or dominant eruption style. For example, the final recorded eruption of Centre Hills, before the initiation of activity at Soufrière Hills, was more silicic than any other identified eruption on Montserrat; and the basaltic South Soufrière Hills episode marked the transition to the current stage of predominantly effusive

Chaos regularization of quantum tunneling rates

International Nuclear Information System (INIS)

Pecora, Louis M.; Wu Dongho; Lee, Hoshik; Antonsen, Thomas; Lee, Ming-Jer; Ott, Edward

2011-01-01

Quantum tunneling rates through a barrier separating two-dimensional, symmetric, double-well potentials are shown to depend on the classical dynamics of the billiard trajectories in each well and, hence, on the shape of the wells. For shapes that lead to regular (integrable) classical dynamics the tunneling rates fluctuate greatly with eigenenergies of the states sometimes by over two orders of magnitude. Contrarily, shapes that lead to completely chaotic trajectories lead to tunneling rates whose fluctuations are greatly reduced, a phenomenon we call regularization of tunneling rates. We show that a random-plane-wave theory of tunneling accounts for the mean tunneling rates and the small fluctuation variances for the chaotic systems.

Public census data on CD-ROM at Lawrence Berkeley Laboratory. Revision 4

Energy Technology Data Exchange (ETDEWEB)

Merrill, D.W.

1993-03-12

The Comprehensive Epidemiologic Data Resource (CEDR) and Populations at Risk to Environmental Pollution (PAREP) projects, of the Information and Computing sciences Division (ICSD) at Lawrence Berkeley Laboratory (LBL), are using public socioeconomic and geographic data files which are available to CEDR and PAREP collaborators via LBL`s computing network. At this time 89 CD-ROM diskettes (approximately 45 gigabytes) are on line via the Unix file server cedrcd.lbl.gov. Most of the files are from the US Bureau of the Census, and many of these pertain to the 1990 Census of Population and Housing. All the CD-ROM diskettes contain documentation in the form of ASCII text files. In addition, printed documentation for most files is available for inspection at University of California Data and Technical Assistance (UC DATA), tel. (510) 642-6571, or the UC Documents Library, tel. (510) 642-2569, both located on the UC Berkeley Campus. Many of the CD-ROM diskettes distributed by the Census Bureau contain software for PC compatible computers, for easily accessing the data. Shared access to the data is maintained through a collaboration among the CEDR and PAREP projects at LBL, and UC DATA, and the UC Documents Library. LBL is grateful to UC DATA and the UC Documents Library for the use of their CD-ROM diskettes. Shared access to LBL facilities may be restricted in the future if costs become prohibitive. Via the Sun Network File System (NFS), these data can be exported to Internet computers for direct access by the user`s application program(s). Due to the size of the files, this access method is preferred over File Transfer Protocol (FTP) access.

Excavation of the Surikamigawa dam diversion tunnel. Surikamigawa dam karihaisui tunnel kantsu

Energy Technology Data Exchange (ETDEWEB)

Ikeda, T.; Konno, T. (Ministry of Construction, Tokyo (Japan))

1994-04-01

A bypass tunnel construction has been completed at the Surikamigawa dam (Japan). This paper describes the summary of the construction. The full-swing dam construction work is scheduled to begin in 1995. The soils distributed near the dam site consist of lapillus tuff containing andesite-based light stones and tuff-based conglomerates containing large gravels. Excavation of the dam diversion tunnel has used a blasting method, and the tunnel construction has adopted an automatic tunnel cross section marking system and a non-electric explosion method. This marking system is a system to irradiate a laser beam onto the facing to depict excavation lines that realizes labor saving and high-accuracy excavation. The error at the tunnel completion was found 20 mm. The non-electric explosion method ignites a coated explosive layer with an impact wave, which is electrostatically safe, and reduces blasting vibration. Electric detonators have also been used because of using ANFO explosives. The result obtained from measurements of inner space displacement necessary for the blasting process has indicated that the area near the dam site consists of stable mountains. 6 figs., 4 tabs.

Charge Islands Through Tunneling

Science.gov (United States)

Robinson, Daryl C.

2002-01-01

It has been recently reported that the electrical charge in a semiconductive carbon nanotube is not evenly distributed, but rather it is divided into charge "islands." This paper links the aforementioned phenomenon to tunneling and provides further insight into the higher rate of tunneling processes, which makes tunneling devices attractive. This paper also provides a basis for calculating the charge profile over the length of the tube so that nanoscale devices' conductive properties may be fully exploited.

Quantifying rockfall risk on roads in the Port Hills, Christchurch, New Zealand

Science.gov (United States)

Unterrader, Stefan; Fuchs, Sven

2016-04-01

specifically, both the annual collective risk and individual risk of being hit by rockfalls on the Port Hills traffic lines were calculated. Both risk terms were assessed by drawing on a well-established method originally developed for evaluating snow avalanche risk on high-alpine pass roads. In order to reflect the discontinuous distribution of rockfall across the hazard zone (i.e. boulders will only hit certain points or follow one specific run-out path compared to the typical snow avalanche run-out behaviour) the original risk equation was adjusted. Hence, (1) the annual collective risk as well as the individual risk of being hit by rockfalls when travelling on the local road network was quantified, (2) the temporal dynamics of most susceptible elements at risk (i.e. commuter traffic) were identified and related dynamics in risk were assessed, and (3) the specific case of waiting traffic and the associated increase in fatality risk compared to moving traffic was computed. The results of this study provide first insights in both the collective and individual rockfall fatality risk on important traffic lines across the Port Hills. Road sections that are most prone to rockfall hazard were clearly identified in high spatial resolution. Sensitivity analysis of main parameters showed that the decrease in seismic hazard expected over the next decades resulted in decreasing rockfall hazard and therefore decreasing fatality risk even if currently increasing traffic volumes will further rise. Furthermore, a closer look on the individual risk of commuters was addressing some of the challenges within the inherent static approach of the risk concept, namely the temporal dynamics in traffic flow. It was further shown that the main traffic line, Tunnel Road, is characterized by a strongly diurnal variability including two traffic peaks between 7 and 9 a.m. and around 5 to 6 p.m. Additionally, the influence of road blockage by boulders falling onto endangered road sections was also

Tunneling progress on the Yucca Mountain Project

International Nuclear Information System (INIS)

Hansmire, W.H.; Munzer, R.J.

1996-01-01

The current status of tunneling progress on the Yucca Mountain Project (YMP) is presented in this paper. The Exploratory Studies Facility (ESF), a key part of the YMP, has been long in development and construction is ongoing. This is a progress report on the tunneling aspects of the ESF as of January 1, 1996. For purposes of discussion in this summary, the tunneling has progressed in four general phases. The paper describes: tunneling in jointed rock under low stress; tunneling through the Bow Ridge Fault and soft rock; tunneling through the Imbricate Fault Zone; and Tunneling into the candidate repository formation

Gender, professionalization, and the child in the Progressive Era: Patty Smith Hill, 1868-1946.

Science.gov (United States)

Allen, Ann Taylor

2011-01-01

This article discusses the career of Patty Smith Hill, a major figure in the American kindergarten movement, in the context of the Progressive Era in American history. Hill, an educator and child-welfare activist, became known both as a reformer of early-childhood education and as an advocate of the inclusion of the kindergarten, originally a private institution, in public-school systems. The article acknowledges this as one of the most significant achievements of the woman-led reform movements of the Progressive Era, but at the same time notes that it involved a substantial transfer of power from the women who had originally developed the kindergarten to the male principals and superintendants who now supervised kindergarten teachers, often without much understanding of their distinctive methods and aims. As a professor at Columbia Teachers College, Hill also exercised an international influence. Hill's career exemplifies broader patterns of women's professionalization during the late-nineteenth and early-twentieth centuries.

Outcomes of arthroscopic "Remplissage": capsulotenodesis of the engaging large Hill-Sachs lesion

Directory of Open Access Journals (Sweden)

Mayo Lee

2011-06-01

Full Text Available Abstract Background A Hill-Sachs lesion of the humeral head after a shoulder dislocation is clinically insignificant in most cases. However, a sizable defect will engage with the anterior rim of the glenoid and cause instability even after anterior glenoid reconstruction. The purpose of this study was to evaluate the outcome of arthroscopic capsulotenodesis of the posterior capsule and infraspinatus tendon ("remplissage" to seal a large engaging Hill-Sachs lesion in an unstable shoulder. Methods This was a prospective follow-up study of patients who underwent arthroscopic surgery for recurrent shoulder instability with a large engaging Hill-Sachs lesion from 2007 to 2009. The clinical results were measured preoperatively and postoperatively with the Simple Shoulder test (SST and the Rowe score for instability. Results Eleven patients met the inclusion criteria of this study. The mean follow-up time was 30 months (range 24 to 35 months. At the last follow-up, significant improvement was observed in both scores with no recurrent dislocations. The mean SST improved from 6.6 to 11 (p Conclusions Arthroscopic remplissage for shoulder instability is an effective soft tissue technique to seal a large engaging Hill-Sachs lesion with respect to recurrence rate, range of motion and shoulder function.

Peak stresses shift from femoral tunnel aperture to tibial tunnel aperture in lateral tibial tunnel ACL reconstructions: a 3D graft-bending angle measurement and finite-element analysis.

Science.gov (United States)

Van Der Bracht, Hans; Tampere, Thomas; Beekman, Pieter; Schepens, Alexander; Devriendt, Wouter; Verdonk, Peter; Victor, Jan

2018-02-01

To investigate the effect of tibial tunnel orientation on graft-bending angle and stress distribution in the ACL graft. Eight cadaveric knees were scanned in extension, 45°, 90°, and full flexion. 3D reconstructions with anatomically placed anterior cruciate ligament (ACL) grafts were constructed with Mimics 14.12 ® . 3D graft-bending angles were measured for classic medial tibial tunnels (MTT) and lateral tibial tunnels (LTT) with different drill-guide angles (DGA) (45°, 55°, 65°, and 75°). A pivot shift was performed on 1 knee in a finite-element analysis. The peak stresses in the graft were calculated for eight different tibial tunnel orientations. In a classic anatomical ACL repair, the largest graft-bending angle and peak stresses are seen at the femoral tunnel aperture. The use of a different DGA at the tibial side does not change the graft-bending angle at the femoral side or magnitude of peak stresses significantly. When using LTT, the largest graft-bending angles and peak stresses are seen at the tibial tunnel aperture. In a classic anatomical ACL repair, peak stresses in the ACL graft are found at the femoral tunnel aperture. When an LTT is used, peak stresses are similar compared to classic ACL repairs, but the location of the peak stress will shift from the femoral tunnel aperture towards the tibial tunnel aperture. the risk of graft rupture is similar for both MTTs and LTTs, but the location of graft rupture changes from the femoral tunnel aperture towards the tibial tunnel aperture, respectively. I.

Hypersonic Tunnel Facility (HTF)

Data.gov (United States)

Federal Laboratory Consortium — The Hypersonic Tunnel Facility (HTF) is a blow-down, non-vitiated (clean air) free-jet wind tunnel capable of testing large-scale, propulsion systems at Mach 5, 6,...

The Synthesis of of Empiricism and Innatism in Berkeley's Doctrine of Notions

Czech Academy of Sciences Publication Activity Database

Hill, James

2010-01-01

Roč. 21, č. 21 (2010), s. 3-15 ISSN 1947-3737 R&D Projects: GA ČR(CZ) GAP401/10/1504 Institutional research plan: CEZ:AV0Z90090514 Keywords : empiricism * innatism * notions Subject RIV: AA - Philosophy ; Religion http://people.hsc.edu/berkeleystudies/issues/BS%20No%20021/BS_021_Hill_Article.pdf

Klein tunneling phenomenon with pair creation process

Science.gov (United States)

Wu, G. Z.; Zhou, C. T.; Fu, L. B.

2018-01-01

In this paper, we study the Klein tunneling phenomenon with electron-positron pair creation process. Pairs can be created from the vacuum by a supercritical single-well potential (for electrons). In the time region, the time-dependent growth pattern of the created pairs can be characterized by four distinct regimes which can be considered as four different statuses of the single well. We find that if positrons penetrate the single well by Klein tunneling in different statuses, the total number of the tunneling positrons will be different. If Klein tunneling begins at the initial stage of the first status i.e. when the sing well is empty, the tunneling process and the total number of tunneling positrons are similar to the traditional Klein tunneling case without considering the pair creation process. As the tunneling begins later, the total tunneling positron number increases. The number will finally settle to an asymptotic value when the tunneling begins later than the settling-down time t s of the single well which has been defined in this paper.

Public census data on CD-ROM at Lawrence Berkeley Laboratory. Revision 1

Energy Technology Data Exchange (ETDEWEB)

Merrill, D.W.

1992-07-02

In connection with the Comprehensive Epidemiologic Data Resource (CEDR) and Populations at Risk to Environmental Pollution (PAREP) projects, of the Information and Computing Sciences Division (ICSD) at Lawrence Berkeley Laboratory (LBL), are using public socioeconomic and geographic data files which are available to CEDR and PAREP collaborators via LBL`s computing network. At this time 67 CD-ROM diskettes (approximately 35 gigabytes) are on line via the Unix file server cedrcd.lbl.gov. Most of the files are from the US Bureau of the Census, and most pertain to the 1990 Census of Population and Housing. This paper contains a list of the CD-ROMs available.

The LBL [Lawrence Berkeley Laboratory] 1-2 GeV synchrotron radiation source

International Nuclear Information System (INIS)

Cornacchia, M.

1987-03-01

A description is presented of the conceptual design of the 1 to 2 GeV Synchrotron Radiation Source proposed for construction at Lawrence Berkeley Laboratory. This facility is designed to produce ultraviolet and soft x-ray radiation. The accelerator complex consists of an injection system (linac plus booster synchrotron) and a low-emittance storage ring optimized for insertion devices. Eleven straight sections are available for undulators and wigglers, and up to 48 photon beam lines may ultimately emanate from bending magnets. Design features of the radiation source are the high brightness of the photon beams, the very short pulses (tens of picoseconds), and the tunability of the radiation

Tunneling time, what is its meaning?

International Nuclear Information System (INIS)

McDonald, C R; Orlando, G; Vampa, G; Brabec, T

2015-01-01

The tunnel time ionization dynamics for bound systems in laser fields are investigated. Numerical analysis for a step function switch-on of the field allows for the tunnel time to be defined as the time it takes the ground state to develop the under-barrier wavefunction components necessary to achieve the static field ionization rate. A relation between the tunnel time and the Keldysh time is established. The definition of the tunnel time is extended to time varying fields and experimental possibilities for measuring the tunnel time are discussed

Decommissioning of fuel PIE caves at Berkeley Nuclear Laboratories

International Nuclear Information System (INIS)

Brant, A.W.

1990-01-01

This paper describes the first major contract awarded to private industry to carry out decommissioning of a facility with significant radiation levels. The work required operatives to work in pressurised suits, entry times were significantly affected by sources of radiation in the Caves, being as low as thirty minutes per day initially. The Caves at Berkeley Nuclear Laboratories carry out post irradiation examination of fuel elements support units and reactor core components from CEGB power stations. The decommissioning work is part of an overall refurbishment of the facility to allow the receipt of AGR Fuel Stringer Component direct from power stations. The paper describes the decommissioning and decontamination of the facility from the remote removal and clean up work carried out by the client to the hands-on work. It includes reference to entry times, work patterns, interfaces with the client and the operations of the laboratory. Details of a specially adapted size reduction method are given. (Author)

Transonic Dynamics Tunnel (TDT)

Data.gov (United States)

Federal Laboratory Consortium — The Transonic Dynamics Tunnel (TDT) is a continuous flow wind-tunnel facility capable of speeds up to Mach 1.2 at stagnation pressures up to one atmosphere. The TDT...

Effects of neglecting carrier tunneling on electrostatic potential in calculating direct tunneling gate current in deep submicron MOSFETs

OpenAIRE

Hakim, MMA; Haque, A

2002-01-01

We investigate the validity of the assumption of neglecting carrier tunneling effects on self-consistent electrostatic potential in calculating direct tunneling gate current in deep submicron MOSFETs. Comparison between simulated and experimental results shows that for accurate modeling of direct tunneling current, tunneling effects on potential profile need to be considered. The relative error in gate current due to neglecting carrier tunneling is higher at higher gate voltages and increases...

Topographical Hill Shading Map Production Based Tianditu (map World)

Science.gov (United States)

Wang, C.; Zha, Z.; Tang, D.; Yang, J.

2018-04-01

TIANDITU (Map World) is the public version of National Platform for Common Geospatial Information Service, and the terrain service is an important channel for users on the platform. With the development of TIANDITU, topographical hill shading map production for providing and updating global terrain map on line becomes necessary for the characters of strong intuition, three-dimensional sense and aesthetic effect. As such, the terrain service of TIANDITU focuses on displaying the different scales of topographical data globally. And this paper mainly aims to research the method of topographical hill shading map production globally using DEM (Digital Elevation Model) data between the displaying scales about 1 : 140,000,000 to 1 : 4,000,000, corresponded the display level from 2 to 7 on TIANDITU website.

Soils of wet valleys in the Larsemann Hills and Vestfold Hills oases (Princess Elizabeth Land, East Antarctica)

Science.gov (United States)

Mergelov, N. S.

2014-09-01

The properties and spatial distribution of soils and soil-like bodies in valleys of the coastal Larsemann Hills and Vestfold Hills oases—poorly investigated in terms of the soil areas of East Antarctica—are discussed. In contrast to Dry Valleys—large continental oases of Western Antarctica—the studied territory is characterized by the presence of temporarily waterlogged sites in the valleys. It is argued that the deficit of water rather than the low temperature is the major limiting factor for the development of living organisms and the pedogenesis on loose substrates. The moisture gradients in the surface soil horizons explain the spatial distribution of the different soils and biotic complexes within the studied valleys. Despite the permanent water-logging of the deep suprapermafrost horizons of most of the soils in the valleys, no gley features have been identified in them. The soils of the wet valleys in the Larsemann Hills oasis do not contain carbonates. They have a slightly acid or neutral reaction. The organic carbon and nitrogen contents are mainly controlled by the amount of living and dead biomass rather than by the humic substances proper. The larger part of the biomass is concentrated inside the mineral soil matrix rather than on the soil surface. The stresses caused by surface drying, strong winds, and ultraviolet radiation prevent the development of organisms on the surface of the soil and necessitate the search for shelter within the soil fine earth material (endoedaphic niche) or under the gravelly pavement (hypolithic niche). In the absence of higher plants, humified products of their decomposition, and rainwater that can wash the soil profile and upon the low content of silt and clay particles in the soil material, "classical" soil horizons are not developed. The most distinct (and, often, the only diagnosed) products of pedogenesis in these soils are represented by organomineral films on the surface of mineral particles.

Road and Railroad Tunnels

Data.gov (United States)

Department of Homeland Security — Tunnels in the United States According to the HSIP Tiger Team Report, a tunnel is defined as a linear underground passageway open at both ends. This dataset is based...

PUREX Storage Tunnels dangerous waste permit application

International Nuclear Information System (INIS)

1991-12-01

The PUREX Storage Tunnels are a mixed waste storage unit consisting of two underground railroad tunnels: Tunnel Number 1 designated 218-E-14 and Tunnel Number 2 designated 218-E-15. The two tunnels are connected by rail to the PUREX Plant and combine to provide storage space for 48 railroad cars (railcars). The PUREX Storage Tunnels provide a long-term storage location for equipment removed from the PUREX Plant. Transfers into the PUREX Storage Tunnels are made on an as-needed basis. Radioactively contaminated equipment is loaded on railcars and remotely transferred by rail into the PUREX Storage Tunnels. Railcars act as both a transport means and a storage platform for equipment placed into the tunnels. This report consists of part A and part B. Part A reports on amounts and locations of the mixed water. Part B permit application consists of the following: Facility Description and General Provisions; Waste Characteristics; Process Information; Groundwater Monitoring; Procedures to Prevent Hazards; Contingency Plan; Personnel Training; Exposure Information Report

Electrically tunable tunneling rectification magnetoresistance in magnetic tunneling junctions with asymmetric barriers.

Science.gov (United States)

Wang, Jing; Huang, Qikun; Shi, Peng; Zhang, Kun; Tian, Yufeng; Yan, Shishen; Chen, Yanxue; Liu, Guolei; Kang, Shishou; Mei, Liangmo

2017-10-26

The development of multifunctional spintronic devices requires simultaneous control of multiple degrees of freedom of electrons, such as charge, spin and orbit, and especially a new physical functionality can be realized by combining two or more different physical mechanisms in one specific device. Here, we report the realization of novel tunneling rectification magnetoresistance (TRMR), where the charge-related rectification and spin-dependent tunneling magnetoresistance are integrated in Co/CoO-ZnO/Co magnetic tunneling junctions with asymmetric tunneling barriers. Moreover, by simultaneously applying direct current and alternating current to the devices, the TRMR has been remarkably tuned in the range from -300% to 2200% at low temperature. This proof-of-concept investigation provides an unexplored avenue towards electrical and magnetic control of charge and spin, which may apply to other heterojunctions to give rise to more fascinating emergent functionalities for future spintronics applications.

Scanning tunneling microscopy

International Nuclear Information System (INIS)

Binnig, G.; Rohrer, H.

1983-01-01

Based on vacuum tunneling, a novel type of microscope, the scanning tunneling microscope (STM) was developed. It has an unprecedented resolution in real space on an atomic scale. The authors review the important technical features, illustrate the power of the STM for surface topographies and discuss its potential in other areas of science and technology. (Auth.)

Scanning tunneling microscope nanoetching method

Science.gov (United States)

Li, Yun-Zhong; Reifenberger, Ronald G.; Andres, Ronald P.

1990-01-01

A method is described for forming uniform nanometer sized depressions on the surface of a conducting substrate. A tunneling tip is used to apply tunneling current density sufficient to vaporize a localized area of the substrate surface. The resulting depressions or craters in the substrate surface can be formed in information encoding patterns readable with a scanning tunneling microscope.

Superconducting tunneling with the tunneling Hamiltonian. II. Subgap harmonic structure

International Nuclear Information System (INIS)

Arnold, G.B.

1987-01-01

The theory of superconducting tunneling without the tunneling Hamiltonian is extended to treat superconductor/insulator/superconductor junctions in which the transmission coefficient of the insulating barrier approaches unity. The solution for the current in such junctions is obtained by solving the problem of a particle hopping in a one-dimensional lattice of sites, with forward and reverse transfer integrals that depend on the site. The results are applied to the problem of subgap harmonic structure in superconducting tunneling. The time-dependent current at finite voltage through a junction exhibiting subgap structure is found to have terms that oscillate at all integer multiples of the Josephson frequency, n(2eV/h). The amplitudes of these new, and as yet unmeasured, ac current contributions as a function of voltage are predicted

Dirac particle tunneling from black rings

International Nuclear Information System (INIS)

Jiang Qingquan

2008-01-01

Recent research shows that Hawking radiation can be treated as a quantum tunneling process, and Hawking temperatures of Dirac particles across the horizon of a black hole can be correctly recovered via the fermion tunneling method. In this paper, motivated by the fermion tunneling method, we attempt to apply the analysis to derive Hawking radiation of Dirac particles via tunneling from black ring solutions of 5-dimensional Einstein-Maxwell-dilaton gravity theory. Finally, it is interesting to find that, as in the black hole case, fermion tunneling can also result in correct Hawking temperatures for the rotating neutral, dipole, and charged black rings.

Engineers win award for Swiss tunnel

CERN Multimedia

2003-01-01

A Derby engineering consultancy has won the Tunnelling Industry Award 2003 for Excellence in Tunnel Design, offered by the British Tunnelling Society, for its work on the LHC in Geneva, Switzerland (1/2 page).

Semiclassical description of resonant tunneling

International Nuclear Information System (INIS)

Bogomolny, E.B.; Rouben, D.C.

1996-01-01

A semiclassical formula is calculated for the tunneling current of electrons trapped in a potential well which can tunnel into and across a wide quantum well. The tunneling current is measured at the second interface of this well and the calculations idealized an experimental situation where a strong magnetic field tilted with respect to an electric field was used. It is shown that the contribution to the tunneling current, due to trajectories which begin at the first interface and end on the second, is dominant for periodic orbits which hit both walls of the quantum well. (author)

A Top Pilot Tunnel Preconditioning Method for the Prevention of Extremely Intense Rockbursts in Deep Tunnels Excavated by TBMs

Science.gov (United States)

Zhang, Chuanqing; Feng, Xiating; Zhou, Hui; Qiu, Shili; Wu, Wenping

2012-05-01

The headrace tunnels at the Jinping II Hydropower Station cross the Jinping Mountain with a maximum overburden depth of 2,525 m, where 80% of the strata along the tunnels consist of marble. A number of extremely intense rockbursts occurred during the excavation of the auxiliary tunnels and the drainage tunnel. In particular, a tunnel boring machine (TBM) was destroyed by an extremely intense rockburst in a 7.2-m-diameter drainage tunnel. Two of the four subsequent 12.4-m-diameter headrace tunnels will be excavated with larger size TBMs, where a high risk of extremely intense rockbursts exists. Herein, a top pilot tunnel preconditioning method is proposed to minimize this risk, in which a drilling and blasting method is first recommended for the top pilot tunnel excavation and support, and then the TBM excavation of the main tunnel is conducted. In order to evaluate the mechanical effectiveness of this method, numerical simulation analyses using the failure approaching index, energy release rate, and excess shear stress indices are carried out. Its construction feasibility is discussed as well. Moreover, a microseismic monitoring technique is used in the experimental tunnel section for the real-time monitoring of the microseismic activities of the rock mass in TBM excavation and for assessing the effect of the top pilot tunnel excavation in reducing the risk of rockbursts. This method is applied to two tunnel sections prone to extremely intense rockbursts and leads to a reduction in the risk of rockbursts in TBM excavation.

Tunneling Ionization of Diatomic Molecules

DEFF Research Database (Denmark)

Svensmark, Jens Søren Sieg

2016-01-01

When a molecule is subject to a strong laser field, there is a probability that an electron can escape, even though the electrons are bound by a large potential barrier. This is possible because electrons are quantum mechanical in nature, and they are therefore able to tunnel through potential...... barriers, an ability classical particles do not possess. Tunnelling is a fundamental quantum mechanical process, a process that is distinctly non-classical, so solving this tunnelling problem is not only relevant for molecular physics, but also for quantum theory in general. In this dissertation the theory...... of tunneling ionizaion of molecules is presented and the results of numerical calculations are shown. One perhaps surprising result is, that the frequently used Born-Oppenheimer approximation breaks down for weak fields when describing tunneling ionization. An analytic theory applicable in the weak-field limit...

Asymmetric voltage behavior of the tunnel magnetoresistance in double barrier magnetic tunnel junctions

KAUST Repository

Useinov, Arthur

2012-06-01

In this paper, we study the value of the tunnel magnetoresistance (TMR) as a function of the applied voltage in double barrier magnetic tunnel junctions (DMTJs) with the left and right ferromagnetic (FM) layers being pinned and numerically estimate the possible difference of the TMR curves for negative and positive voltages in the homojunctions (equal barriers and electrodes). DMTJs are modeled as two single barrier junctions connected in series with consecutive tunneling (CST). We investigated the asymmetric voltage behavior of the TMR for the CST in the range of a general theoretical model. Significant asymmetries of the experimental curves, which arise due to different annealing regimes, are mostly explained by different heights of the tunnel barriers and asymmetries of spin polarizations in magnetic layers. © (2012) Trans Tech Publications.

Asymmetric voltage behavior of the tunnel magnetoresistance in double barrier magnetic tunnel junctions

KAUST Repository

Useinov, Arthur; Gooneratne, Chinthaka Pasan; Kosel, Jü rgen

2012-01-01

In this paper, we study the value of the tunnel magnetoresistance (TMR) as a function of the applied voltage in double barrier magnetic tunnel junctions (DMTJs) with the left and right ferromagnetic (FM) layers being pinned and numerically estimate the possible difference of the TMR curves for negative and positive voltages in the homojunctions (equal barriers and electrodes). DMTJs are modeled as two single barrier junctions connected in series with consecutive tunneling (CST). We investigated the asymmetric voltage behavior of the TMR for the CST in the range of a general theoretical model. Significant asymmetries of the experimental curves, which arise due to different annealing regimes, are mostly explained by different heights of the tunnel barriers and asymmetries of spin polarizations in magnetic layers. © (2012) Trans Tech Publications.

Tunneling magnetoresistance and electroresistance in Fe/PbTiO3/Fe multiferroic tunnel junctions

International Nuclear Information System (INIS)

Dai, Jian-Qing

2016-01-01

We perform first-principles electronic structure and spin-dependent transport calculations for a Fe/PbTiO 3 /Fe multiferroic tunnel junction with asymmetric TiO 2 - and PbO-terminated interfaces. We demonstrate that the interfacial electronic reconstruction driven by the in situ screening of ferroelectric polarization, in conjunction with the intricate complex band structure of barrier, play a decisive role in controlling the spin-dependent tunneling. Reversal of ferroelectric polarization results in a transition from insulating to half-metal-like conducting state for the interfacial Pb 6p z orbitals, which acts as an atomic-scale spin-valve by releasing the tunneling current in antiparallel magnetization configuration as the ferroelectric polarization pointing to the PbO-terminated interface. This effect produces large change in tunneling conductance. Our results open an attractive avenue in designing multiferroic tunnel junctions with excellent performance by exploiting the interfacial electronic reconstruction originated from the in situ screening of ferroelectric polarization.

Atomistic nature in band-to-band tunneling in two-dimensional silicon pn tunnel diodes

International Nuclear Information System (INIS)

Tabe, Michiharu; Tan, Hoang Nhat; Mizuno, Takeshi; Muruganathan, Manoharan; Anh, Le The; Mizuta, Hiroshi; Nuryadi, Ratno; Moraru, Daniel

2016-01-01

We study low-temperature transport properties of two-dimensional (2D) Si tunnel diodes, or Si Esaki diodes, with a lateral layout. In ordinary Si Esaki diodes, interband tunneling current is severely limited because of the law of momentum conservation, while nanoscale Esaki diodes may behave differently due to the dopants in the narrow depletion region, by atomistic effects which release such current limitation. In thin-Si lateral highly doped pn diodes, we find clear signatures of interband tunneling between 2D-subbands involving phonon assistance. More importantly, the tunneling current is sharply enhanced in a narrow voltage range by resonance via a pair of a donor- and an acceptor-atom in the pn junction region. Such atomistic behavior is recognized as a general feature showing up only in nanoscale tunnel diodes. In particular, a donor-acceptor pair with deeper ground-state energies is likely to be responsible for such a sharply enhanced current peak, tunable by external biases.

Three-dimensional computed tomography measurement accuracy of varying Hill-Sachs lesion size.

Science.gov (United States)

Ho, Anthony; Kurdziel, Michael D; Koueiter, Denise M; Wiater, J Michael

2018-02-01

The glenoid track concept has been proposed to correlate shoulder stability with bone loss. Accurate assessment of Hill-Sachs lesion size preoperatively may affect surgical planning and postoperative outcomes; however, no measurement method has been universally accepted. This study aimed to assess the accuracy and reliability of measuring Hill-Sachs lesion sizes using 3-dimensional (3D) computed tomography (CT). Nine polyurethane humerus bone substitutes were used to create Hill-Sachs lesions of varying sizes with a combination of lesion depth (shallow, intermediate, and deep) and width (small, medium, and large). Specimens were scanned with a clinical CT scanner for size measurements and a micro-CT scanner for measurement of true lesion size. Six evaluators repeated measurements twice in a 2-week interval. Scans were measured by use of 3D CT reconstructions for length, width, and Hill-Sachs interval and with use of 2D CT for depth. The interclass correlation coefficient evaluated interobserver and intraobserver variability and percentage error, and Student t-tests assessed measurement accuracy. Interclass correlation coefficient reliability demonstrated strong agreement for all variables measured (0.856-0.975). Percentage error between measured length and measured depth and the true measurement significantly varied with respect to both lesion depth (P = .003 and P = .005, respectively) and lesion size (P = .049 and P = .004, respectively). The 3D CT imaging is effective and reproducible in determining lesion size. Determination of Hill-Sachs interval width is also reliable when it is applied to the glenoid track concept. Measured values on 3D and 2-dimensional imaging using a conventional CT scanner may slightly underestimate true measurements. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Assessment of Groundwater Resources in Kirana Hills Region, Rabwah, District Chiniot, Pakistan

Directory of Open Access Journals (Sweden)

Mirza Naseer Ahmad

2016-12-01

Full Text Available This study was planned to assess the groundwater quality of the area adjacent to Precambrian Kirana Hills, Pakistan. The majority of the people in the area use groundwater from private wells for drinking and domestic use. Therefore, it is important to provide an overview of the groundwater quality. This information would be beneficial to local people and the administration for selecting suitable water treatment methods. Samples were collected from different wells of Rabwah town, close to the Kirana Hills. Parameters like EC, pH, alkalinity and total dissolved solids (TDS were determined for 142 samples. While 40 samples were analyzed for hardness, Ca, Mg, Cl, SO4, NO3, and F. standards set by the World Health Organization (WHO were considered to evaluate the quality of groundwater. Geographic Information System (GIS was used to interpolate analyzed physicochemical parameters. The results showed that EC, TDS, hardness, Cl, SO4, and Ca were very high in the water samples of the area. Fifty-two percent of samples had pH values lower than the permissible limits. Results suggest that the water quality is extremely adverse close to the hills. The poor water quality in the area near the hills may be due to the limited recharge of aquifers because of the hills and shallow basement, which may act as a barrier to subsurface water movement. Some physical and chemical parameters indicated that the quality of water at deeper levels (i.e. >150 ft is relatively better. This may be due to limited exploitation of water from deeper aquifers as compared to shallow aquifers. Hence, proper aquifer management is required to prevent water quality deterioration due to over exploiataion. NO3 was found within the acceptable limits and all water samples were found free of any significant contamination by human activities.

78 FR 21098 - Black Hills National Forest Advisory Board

Science.gov (United States)

2013-04-09

... Hills National Forest Advisory Board (Board) will meet in Rapid City South Dakota. The Board is... staff before the meeting. The agenda will include time for people to make oral statements of three...

Stormwater Management Plan for the Arden Hills Army Training Site, Arden Hills, Minnesota

Energy Technology Data Exchange (ETDEWEB)

Carr, Adrianne E. [Argonne National Lab. (ANL), Argonne, IL (United States); Wuthrich, Kelsey K. [Argonne National Lab. (ANL), Argonne, IL (United States); Ziech, Angela M. [Argonne National Lab. (ANL), Argonne, IL (United States); Bowen, Esther E. [Argonne National Lab. (ANL), Argonne, IL (United States); Quinn, John [Argonne National Lab. (ANL), Argonne, IL (United States)

2013-03-01

This stormwater management plan focuses on the cantonment and training areas of the Arden Hills Army Training Site (AHATS). The plan relates the site stormwater to the regulatory framework, and it summarizes best management practices to aide site managers in promoting clean site runoff. It includes documentation for a newly developed, detailed model of stormwater flow retention for the entire AHATS property and adjacent upgradient areas. The model relies on established modeling codes integrated in a U.S. Department of Defense-sponsored software tool, the Watershed Modeling System (WMS), and it can be updated with data on changes in land use or with monitoring data.

Quantum tunneling with friction

Science.gov (United States)

Tokieda, M.; Hagino, K.

2017-05-01

Using the phenomenological quantum friction models introduced by P. Caldirola [Nuovo Cimento 18, 393 (1941), 10.1007/BF02960144] and E. Kanai [Prog. Theor. Phys. 3, 440 (1948), 10.1143/ptp/3.4.440], M. D. Kostin [J. Chem. Phys. 57, 3589 (1972), 10.1063/1.1678812], and K. Albrecht [Phys. Lett. B 56, 127 (1975), 10.1016/0370-2693(75)90283-X], we study quantum tunneling of a one-dimensional potential in the presence of energy dissipation. To this end, we calculate the tunneling probability using a time-dependent wave-packet method. The friction reduces the tunneling probability. We show that the three models provide similar penetrabilities to each other, among which the Caldirola-Kanai model requires the least numerical effort. We also discuss the effect of energy dissipation on quantum tunneling in terms of barrier distributions.

INCAS TRISONIC WIND TUNNEL

Directory of Open Access Journals (Sweden)

Florin MUNTEANU

2009-09-01

Full Text Available The 1.2 m x 1.2 m Trisonic Blowdown Wind Tunnel is the largest of the experimental facilities at the National Institute for Aerospace Research - I.N.C.A.S. "Elie Carafoli", Bucharest, Romania. The tunnel has been designed by the Canadian company DSMA (now AIOLOS and since its commissioning in 1978 has performed high speed aerodynamic tests for more than 120 projects of aircraft, missiles and other objects among which the twin jet fighter IAR-93, the jet trainer IAR-99, the MIG-21 Lancer, the Polish jet fighter YRYDA and others. In the last years the wind tunnel has been used mostly for experimental research in European projects such as UFAST. The high flow quality parameters and the wide range of testing capabilities ensure the competitivity of the tunnel at an international level.

In-mine (tunnel-to-tunnel) electrical resistance tomography in South African platinum mines

CSIR Research Space (South Africa)

Van Schoor, Abraham M

2009-12-01

Full Text Available The applicability of tunnel-to-tunnel electrical resistance tomography (ERT) for imaging disruptive geological structures ahead of mining, in an igneous platinum mining environment is assessed. The geophysical targets of interest are slump...

New type of hill-top inflation

Energy Technology Data Exchange (ETDEWEB)

Barvinsky, A.O.; Nesterov, D.V. [Theory Department, Lebedev Physics Institute, Leninsky Prospect 53, Moscow 119991 (Russian Federation); Kamenshchik, A.Yu., E-mail: barvin@td.lpi.ru, E-mail: Alexander.Kamenshchik@bo.infn.it, E-mail: nesterov@td.lpi.ru [Dipartimento di Fisica and INFN, via Irnerio 46, 40126 Bologna (Italy)

2016-01-01

We suggest a new type of hill-top inflation originating from the initial conditions in the form of the microcanonical density matrix for the cosmological model with a large number of quantum fields conformally coupled to gravity. Initial conditions for inflation are set up by cosmological instantons describing underbarrier oscillations in the vicinity of the inflaton potential maximum. These periodic oscillations of the inflaton field and cosmological scale factor are obtained within the approximation of two coupled oscillators subject to the slow roll regime in the Euclidean time. This regime is characterized by rapid oscillations of the scale factor on the background of a slowly varying inflaton, which guarantees smallness of slow roll parameters ε and η of the following inflation stage. A hill-like shape of the inflaton potential is shown to be generated by logarithmic loop corrections to the tree-level asymptotically shift-invariant potential in the non-minimal Higgs inflation model and R{sup 2}-gravity. The solution to the problem of hierarchy between the Planckian scale and the inflation scale is discussed within the concept of conformal higher spin fields, which also suggests the mechanism bringing the model below the gravitational cutoff and, thus, protecting it from large graviton loop corrections.

New type of hill-top inflation

Energy Technology Data Exchange (ETDEWEB)

Barvinsky, A.O. [Theory Department, Lebedev Physics Institute,Leninsky Prospect 53, Moscow 119991 (Russian Federation); Department of Physics, Tomsk State University,Lenin Ave. 36, Tomsk 634050 (Russian Federation); Department of Physics and Astronomy, Pacific Institue for Theoretical Physics,University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Kamenshchik, A.Yu. [Dipartimento di Fisica and INFN,via Irnerio 46, 40126 Bologna (Italy); L.D. Landau Institute for Theoretical Physcis,Kosygin str. 2, 119334 Moscow (Russian Federation); Nesterov, D.V. [Theory Department, Lebedev Physics Institute,Leninsky Prospect 53, Moscow 119991 (Russian Federation)

2016-01-20

We suggest a new type of hill-top inflation originating from the initial conditions in the form of the microcanonical density matrix for the cosmological model with a large number of quantum fields conformally coupled to gravity. Initial conditions for inflation are set up by cosmological instantons describing underbarrier oscillations in the vicinity of the inflaton potential maximum. These periodic oscillations of the inflaton field and cosmological scale factor are obtained within the approximation of two coupled oscillators subject to the slow roll regime in the Euclidean time. This regime is characterized by rapid oscillations of the scale factor on the background of a slowly varying inflaton, which guarantees smallness of slow roll parameters ϵ and η of the following inflation stage. A hill-like shape of the inflaton potential is shown to be generated by logarithmic loop corrections to the tree-level asymptotically shift-invariant potential in the non-minimal Higgs inflation model and R{sup 2}-gravity. The solution to the problem of hierarchy between the Planckian scale and the inflation scale is discussed within the concept of conformal higher spin fields, which also suggests the mechanism bringing the model below the gravitational cutoff and, thus, protecting it from large graviton loop corrections.

Destructive quantum interference in spin tunneling problems

OpenAIRE

von Delft, Jan; Henley, Christopher L.

1992-01-01

In some spin tunneling problems, there are several different but symmetry-related tunneling paths that connect the same initial and final configurations. The topological phase factors of the corresponding tunneling amplitudes can lead to destructive interference between the different paths, so that the total tunneling amplitude is zero. In the study of tunneling between different ground state configurations of the Kagom\\'{e}-lattice quantum Heisenberg antiferromagnet, this occurs when the spi...

The hill forts and castle mounds in Lithuania: interaction between geodiversity and human-shaped landscape

Science.gov (United States)

Skridlaite, Grazina; Guobyte, Rimante; Satkunas, Jonas

2015-04-01

Lithuania is famous for its abundant, picturesque hill forts and castle mounds of natural origin. In Lithuania as well as in whole Europe the fortified hills were used as the society dwelling place since the beginning of the Late Bronze Age. Their importance increased when Livonian and Teutonic Orders directed a series of military campaigns against Lithuania with the aim of expansion of Christianity in the region at the end of 1st millennium AD, and they were intensively used till the beginning of the 15th c. when most of them were burned down during fights with the Orders or just abandoned due to the changing political and economical situation. What types of the geodiversity were used for fortified dwellings? The choice in a particular area depended on a variety of geomorphology left behind the retreating ice sheets. High spots dominating their surroundings were of prime interest. In E and SE Lithuania, the Baltic Upland hills marking the eastern margin of the last Weichselian glacier hosted numerous fortified settlements from the end of 2nd millennium BC to the Medieval Ages (Narkunai, Velikuskes etc). In W Lithuania, plateau-like hills of the insular Samogitian Upland had been repeatedly fortified from the beginning of 1st millennium AD to the 14th century (Satrija, Medvegalis etc). Chains of hill forts and castle mounds feature the slopes of glaciofluvial valleys of Nemunas, Neris and other rivers where the slopes were dissected by affluent rivulets and ravines and transformed into isolated, well protected hills (Kernave, Punia, Veliuona etc). Peninsulas and headlands formed by the erosion of fluvial and lacustrine deposits were used in the lowlands, e.g. in central and N Lithuania (Paberze, Mezotne etc). How much the landscape was modified for defense purposes? Long-term erosion and overgrowing vegetation damaged the former fortified sites, however some remains and the archeological excavations allowed their reconstruction. The fortified Bronze Age settlements

A power function profile of a ski jumping in-run hill.

Science.gov (United States)

Zanevskyy, Ihor

2011-01-01

The aim of the research was to find a function of the curvilinear segment profile which could make possible to avoid an instantaneous increasing of a curvature and to replace a circle arc segment on the in-run of a ski jump without any correction of the angles of inclination and the length of the straight-line segments. The methods of analytical geometry and trigonometry were used to calculate an optimal in-run hill profile. There were two fundamental conditions of the model: smooth borders between a curvilinear segment and straight-line segments of an in-run hill and concave of the curvilinear segment. Within the framework of this model, the problem has been solved with a reasonable precision. Four functions of a curvilinear segment profile of the in-run hill were investigated: circle arc, inclined quadratic parabola, inclined cubic parabola, and power function. The application of a power function to the in-run profile satisfies equal conditions for replacing a circle arc segment. Geometrical parameters of 38 modern ski jumps were investigated using the methods proposed.

Snow and ice blocking of tunnels

Energy Technology Data Exchange (ETDEWEB)

Lia, Leif

1998-12-31

Hydroelectric power development in cold regions causes much concern about operational reliability and dam safety. This thesis studies the temperature distribution in tunnels by means of air temperature measurements in six tunnel spillways and five diversion tunnels. The measurements lasted for two consecutive winters. The air through flow tunnel is used as it causes cooling of both rock and water. In open spillway tunnels, frost reaches the entire tunnel. In spillway tunnels with walls, the frost zones reach about 100 m from the downstream end. In mildly-inclined diversion tunnels, a frost free zone is located in the middle of the tunnel and snow and ice problems were only observed in the inlet and outlet. Severe aufeis is accumulation is observed in the frost zones. The heat transfer from rock to air, water and ice is calculated and used in a prediction model for the calculation of aufeis build-up together with local field observation data. The water penetration of snow plugs is also calculated, based on the heat balance. It takes 20 to 50 days for water to enter the blocked tunnel. The empirical values are 30 to 60 days, but only 1 day if the temperature of the snow pack is 0{sup o}C. Sensitivity analyses are carried out for temperature variations in rock, snow, water and ice. Systematic field observation shows that it is important for hydropower companies to know about the effects of snow and ice blocking in an area. A risk analysis of dam safety is presented for a real case. Finally, the thesis proposes solutions which can reduce the snow and ice problems. 79 refs., 63 figs., 11 tabs.

Investigation of Corner Effect and Identification of Tunneling Regimes in L-Shaped Tunnel Field-Effect-Transistor.

Science.gov (United States)

Najam, Faraz; Yu, Yun Seop

2018-09-01

Corner-effect existing in L-shaped tunnel field-effect-transistor (LTFET) was investigated using numerical simulations and band diagram analysis. It was found that the corner-effect is caused by the convergence of electric field in the sharp source corner present in an LTFET, thereby increasing the electric field in the sharp source corner region. It was found that in the corner-effect region tunneling starts early, as a function of applied bias, as compared to the rest of the channel not affected by corner-effect. Further, different tunneling regimes as a function of applied bias were identified in the LTFET including source to channel and channel to channel tunneling regimes. Presence of different tunneling regimes in LTFET was analytically justified with a set of equations developed to model source to channel, and channel to channel tunneling currents. Drain-current-gate-voltage (Ids-Vgs) characteristics obtained from the equations is in reasonable qualitative agreement with numerical simulation.

Scanning Tunneling Optical Resonance Microscopy

Science.gov (United States)

Bailey, Sheila; Wilt, Dave; Raffaelle, Ryne; Gennett, Tom; Tin, Padetha; Lau, Janice; Castro, Stephanie; Jenkins, Philip; Scheiman, Dave

2003-01-01

Scanning tunneling optical resonance microscopy (STORM) is a method, now undergoing development, for measuring optoelectronic properties of materials and devices on the nanoscale by means of a combination of (1) traditional scanning tunneling microscopy (STM) with (2) tunable laser spectroscopy. In STORM, an STM tip probing a semiconductor is illuminated with modulated light at a wavelength in the visible-to-near-infrared range and the resulting photoenhancement of the tunneling current is measured as a function of the illuminating wavelength. The photoenhancement of tunneling current occurs when the laser photon energy is sufficient to excite charge carriers into the conduction band of the semiconductor. Figure 1 schematically depicts a proposed STORM apparatus. The light for illuminating the semiconductor specimen at the STM would be generated by a ring laser that would be tunable across the wavelength range of interest. The laser beam would be chopped by an achromatic liquid-crystal modulator. A polarization-maintaining optical fiber would couple the light to the tip/sample junction of a commercial STM. An STM can be operated in one of two modes: constant height or constant current. A STORM apparatus would be operated in the constant-current mode, in which the height of the tip relative to the specimen would be varied in order to keep the tunneling current constant. In this mode, a feedback control circuit adjusts the voltage applied to a piezoelectric actuator in the STM that adjusts the height of the STM tip to keep the tunneling current constant. The exponential relationship between the tunneling current and tip-to-sample distance makes it relatively easy to implement this mode of operation. The choice of method by which the photoenhanced portion of the tunneling current would be measured depends on choice of the frequency at which the input illumination would be modulated (chopped). If the frequency of modulation were low enough (typically tunneling current

Fiber coupled ultrafast scanning tunneling microscope

DEFF Research Database (Denmark)

Keil, Ulrich Dieter Felix; Jensen, Jacob Riis; Hvam, Jørn Märcher

1997-01-01

We report on a scanning tunneling microscope with a photoconductive gate in the tunneling current circuit. The tunneling tip is attached to a coplanar transmission line with an integrated photoconductive switch. The switch is illuminated through a fiber which is rigidly attached to the switch...... waveguide. The measurements show that the probe works as a transient voltage detector in contact and a capacitively coupled transient field detector in tunneling mode. We do not measure the transient voltage change in the ohmic tunneling current. In this sense, the spatial resolution for propagating...... substrate. By using a firmly attached fiber we achieve an excellent reproducibility and unconstrained positioning of the tip. We observe a transient signal with 2.9 ps pulse width in tunneling mode and 5 ps in contact mode. The instrument is applied to investigating the mode structure on a coplanar...

Hill climbing algorithms and trivium

DEFF Research Database (Denmark)

Borghoff, Julia; Knudsen, Lars Ramkilde; Matusiewicz, Krystian

2011-01-01

This paper proposes a new method to solve certain classes of systems of multivariate equations over the binary field and its cryptanalytical applications. We show how heuristic optimization methods such as hill climbing algorithms can be relevant to solving systems of multivariate equations....... A characteristic of equation systems that may be efficiently solvable by the means of such algorithms is provided. As an example, we investigate equation systems induced by the problem of recovering the internal state of the stream cipher Trivium. We propose an improved variant of the simulated annealing method...

Fuel management optimization in pressure water reactors with hexagonal geometry using hill climbing method

International Nuclear Information System (INIS)

Andres Diaz, J.; Quintero, Ruben; Melian, Manuel; Rosete, Alejandro

2000-01-01

In this work the general-purpose optimization method, Hill Climbing, was applied to the Fuel Management Optimization problem in PWR reactors, WWER type. They were carried out a series of experiments in order to study the performance of Hill Climbing. It was proven two starting point for initialize the search: a reload configuration by project and a reload configuration generated with the application of a minimal knowledge of the problem. It was also studied the effect of imposing constraints based on the physics of the reactor in order to reduce the number of possible solutions to be generated. The operator used in Hill Climbing was defined as a binary exchange of fuel assemblies. For the simulation of each generated configuration, the tridimensional simulator program SPPS-1 was used. It was formulated an objective function with power peaking constraint to guide the search. As results, a methodology ws proposed for the In-core Fuel Management Optimization in hexagonal geometry, and the feasibility of the application of the Hill Climbing to this type of problem was demonstrated. (author)

Experimental Evidence for Quantum Tunneling Time

Science.gov (United States)

Camus, Nicolas; Yakaboylu, Enderalp; Fechner, Lutz; Klaiber, Michael; Laux, Martin; Mi, Yonghao; Hatsagortsyan, Karen Z.; Pfeifer, Thomas; Keitel, Christoph H.; Moshammer, Robert

2017-07-01

The first hundred attoseconds of the electron dynamics during strong field tunneling ionization are investigated. We quantify theoretically how the electron's classical trajectories in the continuum emerge from the tunneling process and test the results with those achieved in parallel from attoclock measurements. An especially high sensitivity on the tunneling barrier is accomplished here by comparing the momentum distributions of two atomic species of slightly deviating atomic potentials (argon and krypton) being ionized under absolutely identical conditions with near-infrared laser pulses (1300 nm). The agreement between experiment and theory provides clear evidence for a nonzero tunneling time delay and a nonvanishing longitudinal momentum of the electron at the "tunnel exit."

Tunneling from the past horizon

Science.gov (United States)

Kang, Subeom; Yeom, Dong-han

2018-04-01

We investigate a tunneling and emission process of a thin-shell from a Schwarzschild black hole, where the shell was initially located beyond the Einstein-Rosen bridge and finally appears at the right side of the Penrose diagram. In order to obtain such a solution, we should assume that the areal radius of the black hole horizon increases after the tunneling. Hence, there is a parameter range such that the tunneling rate is exponentially enhanced, rather than suppressed. We may have two interpretations regarding this. First, such a tunneling process from the past horizon is improbable by physical reasons; second, such a tunneling is possible in principle, but in order to obtain a stable Einstein-Rosen bridge, one needs to restrict the parameter spaces. If such a process is allowed, this can be a nonperturbative contribution to Einstein-Rosen bridges as well as eternal black holes.

Public census data on CD-ROM at Lawrence Berkeley Laboratory. Revision 3

Energy Technology Data Exchange (ETDEWEB)

Merrill, D.W.

1993-01-16

The Comprehensive Epidemiologic Data Resource (CEDR) and Populations at Risk to Environmental Pollution (PAREP) projects, of the Information and Computing Sciences Division (ICSD) at Lawrence Berkeley Laboratory (LBL), are using public socioeconomic and geographic data files which are available to CEDR and PAREP collaborators via LBL`s computing network. At this time 72 CD-ROM diskettes (approximately 37 gigabytes) are on line via the Unix file server ``cedrcd.lbl.gov``. Most of the files are from the US Bureau of the Census, and many of these pertain to the 1990 Census of Population and Housing. All the CD-ROM diskettes contain documentation in the form of ASCII text files. In addition, printed documentation for most files is available for inspection at University of California Data and Technical Assistance (UC DATA), tel. (510) 642-6571, or the UC Documents Library, tel. (510) 642-2569, both located on the UC Berkeley Campus. Many of the CD-ROM diskettes distributed by the Census Bureau contain software for PC compatible computers, for easily accessing the data. Shared access to the data is maintained through a collaboration among the CEDR and PAREP projects at LBL, and UC DATA, and the UC Documents Library. LBL is grateful to UC DATA and the UC Documents Library for the use of their CD-ROM diskettes. Shared access to LBL facilities may be restricted in the future if costs become prohibitive. Via the Sun Network File System (NFS), these data can be exported to Internet computers for direct access by the user`s application program(s). Due to the size of the files, this access method is preferred over File Transfer Protocol (FTP) access. Please contact Deane Merrill (dwmerrill@lbl.gov) if you wish to make use of the data.

Molecular series-tunneling junctions.

Science.gov (United States)

Liao, Kung-Ching; Hsu, Liang-Yan; Bowers, Carleen M; Rabitz, Herschel; Whitesides, George M

2015-05-13

Charge transport through junctions consisting of insulating molecular units is a quantum phenomenon that cannot be described adequately by classical circuit laws. This paper explores tunneling current densities in self-assembled monolayer (SAM)-based junctions with the structure Ag(TS)/O2C-R1-R2-H//Ga2O3/EGaIn, where Ag(TS) is template-stripped silver and EGaIn is the eutectic alloy of gallium and indium; R1 and R2 refer to two classes of insulating molecular units-(CH2)n and (C6H4)m-that are connected in series and have different tunneling decay constants in the Simmons equation. These junctions can be analyzed as a form of series-tunneling junctions based on the observation that permuting the order of R1 and R2 in the junction does not alter the overall rate of charge transport. By using the Ag/O2C interface, this system decouples the highest occupied molecular orbital (HOMO, which is localized on the carboxylate group) from strong interactions with the R1 and R2 units. The differences in rates of tunneling are thus determined by the electronic structure of the groups R1 and R2; these differences are not influenced by the order of R1 and R2 in the SAM. In an electrical potential model that rationalizes this observation, R1 and R2 contribute independently to the height of the barrier. This model explicitly assumes that contributions to rates of tunneling from the Ag(TS)/O2C and H//Ga2O3 interfaces are constant across the series examined. The current density of these series-tunneling junctions can be described by J(V) = J0(V) exp(-β1d1 - β2d2), where J(V) is the current density (A/cm(2)) at applied voltage V and βi and di are the parameters describing the attenuation of the tunneling current through a rectangular tunneling barrier, with width d and a height related to the attenuation factor β.

Dental disease control in Pine Hill, New Mexico.

Science.gov (United States)

Carberry, Frank J; Cloud, Bill; Finster, Carolyn

2004-02-01

One-year results of a community-operated dental disease control project in Pine Hill, New Mexico. The program uses fluoride, chiefly rinse, and has not only reduced the amount of decay in permanent teeth, but has markedly reduced the need for restorative care of primary teeth.

Automated Boundary Conditions for Wind Tunnel Simulations

Science.gov (United States)

Carlson, Jan-Renee

2018-01-01

Computational fluid dynamic (CFD) simulations of models tested in wind tunnels require a high level of fidelity and accuracy particularly for the purposes of CFD validation efforts. Considerable effort is required to ensure the proper characterization of both the physical geometry of the wind tunnel and recreating the correct flow conditions inside the wind tunnel. The typical trial-and-error effort used for determining the boundary condition values for a particular tunnel configuration are time and computer resource intensive. This paper describes a method for calculating and updating the back pressure boundary condition in wind tunnel simulations by using a proportional-integral-derivative controller. The controller methodology and equations are discussed, and simulations using the controller to set a tunnel Mach number in the NASA Langley 14- by 22-Foot Subsonic Tunnel are demonstrated.

Lawrence Berkeley National Laboratory 1995 site environmental report: Volume 2, Data appendix

International Nuclear Information System (INIS)

1996-07-01

Ernest Orlando Lawrence Berkeley National Laboratory presents Volume II, Data Appendix as a reference document to supplement the 1995 Site Environmental Report. Volume II contains the raw environmental monitoring and sampling data used to generate many of the summary results included in the main report. Supplemental data is provided for sitewide activities involving the media of stack and ambient air quality, rainwater, surface water, stormwater, wastewater, and soil and sediment. Volume II also contains supplemental data on the special preoperational monitoring study for the new Hazardous Waste Handling Facility. The Table of Contents provides a cross-reference to the data tables of the main report and this appendix. Data are given in System International (SI) units

Environmental protection and regulatory compliance at the Elk Hills field

International Nuclear Information System (INIS)

Chappelle, H.H.; Donahoe, R.L.; Kato, T.T.; Ordway, H.E.

1991-01-01

Environmental protection has played an integral role in the development and operation of the Elk Hills field since production at the maximum efficient rate was authorized in 1976. The field is located in a non-attainment area for California and National Ambient Air Quality Standards for two criteria pollutants and their associated precursors, is home to four endangered species, and operates within the California regulatory framework. Environmental protection and regulatory compliance is a multi-faceted program carried out through a substantial commitment of resources and workforce involvement. This paper describes the actions taken and resources employed to protect the environment, specific technologies and projects implemented, and the ongoing nature of these efforts at Elk Hills

One-Way Nested Large-Eddy Simulation over the Askervein Hill

Directory of Open Access Journals (Sweden)

James D. Doyle

2009-07-01

Full Text Available Large-eddy simulation (LES models have been used extensively to study atmospheric boundary layer turbulence over flat surfaces; however, LES applications over topography are less common. We evaluate the ability of an existing model – COAMPS^®-LES – to simulate flow over terrain using data from the Askervein Hill Project. A new approach is suggested for the treatment of the lateral boundaries using one-way grid nesting. LES wind profile and speed-up are compared with observations at various locations around the hill. The COAMPS-LES model performs generally well. This case could serve as a useful benchmark for evaluating LES models for applications over topography.

Stochastic modeling and simulation of reaction-diffusion system with Hill function dynamics.

Science.gov (United States)

Chen, Minghan; Li, Fei; Wang, Shuo; Cao, Young

2017-03-14

Stochastic simulation of reaction-diffusion systems presents great challenges for spatiotemporal biological modeling and simulation. One widely used framework for stochastic simulation of reaction-diffusion systems is reaction diffusion master equation (RDME). Previous studies have discovered that for the RDME, when discretization size approaches zero, reaction time for bimolecular reactions in high dimensional domains tends to infinity. In this paper, we demonstrate that in the 1D domain, highly nonlinear reaction dynamics given by Hill function may also have dramatic change when discretization size is smaller than a critical value. Moreover, we discuss methods to avoid this problem: smoothing over space, fixed length smoothing over space and a hybrid method. Our analysis reveals that the switch-like Hill dynamics reduces to a linear function of discretization size when the discretization size is small enough. The three proposed methods could correctly (under certain precision) simulate Hill function dynamics in the microscopic RDME system.

FUNDAMENTAL TUNNELING PROCESSES IN MOSa SOLAR CELLS

OpenAIRE

Balberg , I.; Hanak , J.; Weakliem , H.; Gal , E.

1981-01-01

In previous studies of tunneling through a MOSa tunnel junction, where Sa was a-Si : H, it was shown that their characteristics resemble those of MOSc devices where Sc was crystalline silicon. In the present work we would like to report a demonstration of fundamental tunneling processes in such tunnel junctions. In particular, the transition from semiconductor controlled regime to tunneling controlled regime can be clearly distinguished. The present results represent one of the rare cases whe...

AN INTRODUCTION TO EXPLORING LAW, DISABILITY, AND THE CHALLENGE OF EQUALITY IN CANADA AND THE UNITED STATES: PAPERS FROM THE BERKELEY SYMPOSIUM

Directory of Open Access Journals (Sweden)

Laverne Jacobs

2015-10-01

Full Text Available It brings me great pleasure to write this Introduction to Exploring Law, Disability, and the Challenge of Equality in Canada and the United States. This special collection of articles in the Windsor Yearbook of Access to Justice [WYAJ] stems from a symposium of the same name held at the Berkeley Law School at the University of California on 5 December 2014. Writing this introduction allows me to bring together my identities as a law and disability scholar, the principal organizer and convener of the Berkeley Symposium, and editor-in-chief of the WYAJ. In these roles, I have had the opportunity to engage with this set of articles and their authors in a distinct way – from the early versions of these articles through to the final peer-reviewed publications. The Berkeley Symposium is the first conference, of which we are aware, to bring together scholars and experts from both Canada and the United States to present research and exchange ideas on equality issues affecting persons with disabilities in both countries.1 Each academic was invited to write about an equality issue of their choice that is of contemporary concern to persons with disabilities, and to focus on Canada, the United States,or both, at their  option. The result is a set of articles that is simultaneously introspective and comparative.

Distribution of tunnelling times for quantum electron transport

International Nuclear Information System (INIS)

Rudge, Samuel L.; Kosov, Daniel S.

2016-01-01

In electron transport, the tunnelling time is the time taken for an electron to tunnel out of a system after it has tunnelled in. We define the tunnelling time distribution for quantum processes in a dissipative environment and develop a practical approach for calculating it, where the environment is described by the general Markovian master equation. We illustrate the theory by using the rate equation to compute the tunnelling time distribution for electron transport through a molecular junction. The tunnelling time distribution is exponential, which indicates that Markovian quantum tunnelling is a Poissonian statistical process. The tunnelling time distribution is used not only to study the quantum statistics of tunnelling along the average electric current but also to analyse extreme quantum events where an electron jumps against the applied voltage bias. The average tunnelling time shows distinctly different temperature dependence for p- and n-type molecular junctions and therefore provides a sensitive tool to probe the alignment of molecular orbitals relative to the electrode Fermi energy.

Radiometric evidence of Middle Devonian inversion of the Hill End Trough, northeast Lachlan Fold Belt

International Nuclear Information System (INIS)

Pakham, G.H.

1999-01-01

The publication of a new geological time-scale by the Australian Geological Survey Organisation and radiometric dates from the Hill End goldfield have prompted the re-examination of the timing of deformation of the Hill End Trough to determine whether it occurred in Middle Devonian or Early Carboniferous time. Palaeontological evidence from the western trough margin and the Capertee High dates the end of deposition in the trough as late Emsian or early Eifelian (385-382 Ma). After a mid-Devonian hiatus of at least 15 million years, paralic sedimentation commenced on the Molong and Capertee Highs in late Frasnian or early Famennian time (367-363 Ma). No Upper Devonian sedimentary formations occur in the Hill End Trough. Structural relationships indicate that the oldest mineral veins at Hill End preceded cleavage formation in the deformed trough sedimentary rocks. Early vein muscovites have Middle Devonian 40 Ar/ 39 Ar dates of 380-370 Ma. Regional metamorphic biotites from Hill End have well constrained 40 Ar/ 39 Ar closing ages of 360-358 Ma (mid-Famennian). The metamorphic (thermal) maximum which outlasted penetrative deformation. is estimated here by modelling to have been about 370 Ma (latest Givetian). This clearly places the earlier main deformation in the Middle Devonian. Deformation probably began by terminating trough deposition in latest Emsian to early Eifelian time and ended in early Givetian time at about 375 Ma ago. Published pressure and temperature data from the Hill End goldfield suggest that deformation thickened the 6 km sediment column to around 11 km. The thermal model suggests there was post-deformation erosion of about 4km and little if any further erosion occurred during Late Devonian to Early Carboniferous time. The shortening accompanying the inversion of the northern Hill End Trough may have been taken up in the region to the south, both east and west of the Copperhannia Thrust, and east of the southern termination of the Capertee High

Een systeem voor classificatie van korte tunnels.

NARCIS (Netherlands)

Schreuder, D.A.

1985-01-01

The most difficult problems in the lighting of tunnels occur in daylight and in particular in the entrance of the tunnel, while drivers approaching the tunnel must be able to look into the tunnel from the outside to detect the road course and eventual obstacles. A classification should The made on

Effects of the finite duration of quantum tunneling in laser-assisted scanning tunneling microscopy

International Nuclear Information System (INIS)

Hagmann, M.J.

1994-01-01

Previous measurements of tunnel conductance in heterostructures and experiments with Josephson junctions suggest quantum tunneling has a definite duration. The authors use semiclassical methods to determine the effects of this delay on the tunneling current in a laser-assisted STM. A planar-planar STM model is used with the exact multiple image potential, and the energy distribution for a free-electron metal. It is necessary to average over the phase at barrier entry, and iteration with back propagated solutions is required to obtain the transmission coefficients for evenly spaced phases and specified energies at barrier entry. The simulations suggest that the dependence of the tunneling current on the wavelength of illumination can serve as a basis for determining the duration of barrier traversal. A power flux density of 10 11 W/m 2 would be required at several wavelengths from 1 to 10 μm. It is possible that thermal effects could be separated from the modeled phenomena by determining the time dependence of the tunneling current with a pulsed laser

Dependences of the Tunnel Magnetoresistance and Spin Transfer Torque on the Sizes and Concentration of Nanoparticles in Magnetic Tunnel Junctions

Science.gov (United States)

Esmaeili, A. M.; Useinov, A. N.; Useinov, N. Kh.

2018-01-01

Dependences of the tunnel magnetoresistance and in-plane component of the spin transfer torque on the applied voltage in a magnetic tunnel junction have been calculated in the approximation of ballistic transport of conduction electrons through an insulating layer with embedded magnetic or nonmagnetic nanoparticles. A single-barrier magnetic tunnel junction with a nanoparticle embedded in an insulator forms a double-barrier magnetic tunnel junction. It has been shown that the in-plane component of the spin transfer torque in the double-barrier magnetic tunnel junction can be higher than that in the single-barrier one at the same thickness of the insulating layer. The calculations show that nanoparticles embedded in the tunnel junction increase the probability of tunneling of electrons, create resonance conditions, and ensure the quantization of the conductance in contrast to the tunnel junction without nanoparticles. The calculated dependences of the tunnel magnetoresistance correspond to experimental data demonstrating peak anomalies and suppression of the maximum magnetoresistances at low voltages.

Proceedings of the meeting on tunneling reaction and low temperature chemistry, 98 August. Tunneling reaction and its theory

Energy Technology Data Exchange (ETDEWEB)

Miyazaki, Tetsuo; Aratono, Yasuyuki; Ichikawa, Tsuneki; Shiotani, Masaru [eds.

1998-10-01

Present report is the proceedings of the 4th Meeting on Tunneling Reaction and Low Temperature Chemistry held in August 3 and 4, 1998. The main subject of the meeting is `Tunneling Reaction and Its Theory`. In the present meeting the theoretical aspects of tunneling phenomena in the chemical reaction were discussed intensively as the main topics. Ten reports were presented on the quantum diffusion of muon and proton in the metal and H{sub 2}{sup -} anion in the solid para-hydrogen, the theory of tunnel effect in the nuclear reaction and the tunneling reaction in the organic compounds. One special lecture was presented by Prof. J. Kondo on `Proton Tunneling in Solids`. The 11 of the presented papers are indexed individually. (J.P.N.)

Strain-enhanced tunneling magnetoresistance in MgO magnetic tunnel junctions.

Science.gov (United States)

Loong, Li Ming; Qiu, Xuepeng; Neo, Zhi Peng; Deorani, Praveen; Wu, Yang; Bhatia, Charanjit S; Saeys, Mark; Yang, Hyunsoo

2014-09-30

While the effects of lattice mismatch-induced strain, mechanical strain, as well as the intrinsic strain of thin films are sometimes detrimental, resulting in mechanical deformation and failure, strain can also be usefully harnessed for applications such as data storage, transistors, solar cells, and strain gauges, among other things. Here, we demonstrate that quantum transport across magnetic tunnel junctions (MTJs) can be significantly affected by the introduction of controllable mechanical strain, achieving an enhancement factor of ~2 in the experimental tunneling magnetoresistance (TMR) ratio. We further correlate this strain-enhanced TMR with coherent spin tunneling through the MgO barrier. Moreover, the strain-enhanced TMR is analyzed using non-equilibrium Green's function (NEGF) quantum transport calculations. Our results help elucidate the TMR mechanism at the atomic level and can provide a new way to enhance, as well as tune, the quantum properties in nanoscale materials and devices.

HILL: The High-Intensity Laser Laboratory Core Team's Reply to Questions from the NNSA Experimental Facilities Panel

International Nuclear Information System (INIS)

Albright, B.J.

2012-01-01

Question 1 - The type of physics regimes that HILL can access for weapons studies is quite interesting. The question that arises for the proposal team is what priority does this type of experimental data have versus data that can be obtained with NIF, and Z. How does HILL rank in priority compared to MARIE 1.0 in terms of the experimental data it will provide? We reiterate that isochoric heating experiments to be conducted with HILL are complementary to the high energy density physics experiments at NIF and Z and uniquely access states of matter that neither other facility can access. It is our belief that HILL will enable several important questions, e.g., as related to mix morphology, radiation transfer from corrugated surfaces, and equations of state, to be run to ground through carefully diagnosed, 'unit-physics' experiments. Such experiments will substantially improve confidence in our computer models and provide a rigorous science basis for certification. Question 2 - A secondary question relates to the interests of LLNL and SNL in the physics that HILL can address. This should be spelled out clearly. I would like to see the other labs be part of the discussion regarding how important this capability would be if built. Both sister Labs have a keen interest in the physics enabled by high-intensity, high-energy lasers, as evinced by the Z Petawatt and NIF ARC upgrades to their signature facilities. LANL scientists have teamed with scientists from both Laboratories in high-intensity laser 'first experiments' envisioned for HILL and we fully intend to continue these profitable discussions going forward. In the preparation of the HILL proposal, feedback was solicited from the broader HEDP and weapons science communities. The consensus view was that HILL filled a critical gap and that there was a need for a facility like HILL to address outstanding questions in weapons science. It was recognized that co-location of HILL with a facility such as MaRIE 1.0, Z, NIF, or

Trap assisted tunneling and its effect on subthreshold swing of tunnel field effect transistors

OpenAIRE

Sajjad, Redwan N.; Chern, Winston; Hoyt, Judy L.; Antoniadis, Dimitri A.

2016-01-01

We provide a detailed study of the interface Trap Assisted Tunneling (TAT) mechanism in tunnel field effect transistors to show how it contributes a major leakage current path before the Band To Band Tunneling (BTBT) is initiated. With a modified Shockley-Read-Hall formalism, we show that at room temperature, the phonon assisted TAT current always dominates and obscures the steep turn ON of the BTBT current for common densities of traps. Our results are applicable to top gate, double gate and...

Geologic map of the Bodie Hills, California and Nevada

Science.gov (United States)

John, David A.; du Bray, Edward A.; Box, Stephen E.; Vikre, Peter G.; Rytuba, James J.; Fleck, Robert J.; Moring, Barry C.

2015-01-01

The Bodie Hills covers about 1,200 km2 straddling the California-Nevada state boundary just north of Mono Lake in the western part of the Basin and Range Province, about 20 km east of the central Sierra Nevada. The area is mostly underlain by the partly overlapping, middle to late Miocene Bodie Hills volcanic field and Pliocene to late Pleistocene Aurora volcanic field (John and others, 2012). Upper Miocene to Pliocene sedimentary deposits, mostly basin-filling sediments, gravel deposits, and fanglomerates, lap onto the west, north, and east sides of the Bodie Hills, where they cover older Miocene volcanic rocks. Quaternary surficial deposits, including extensive colluvial, fluvial, glacial, and lacustrine deposits, locally cover all older rocks. Miocene and younger rocks are tilted ≤30° in variable directions. These rocks are cut by several sets of high-angle faults that exhibit a temporal change from conjugate northeast-striking left-lateral and north-striking right-lateral oblique-slip faults in rocks older than about 9 Ma to north- and northwest-striking dip-slip faults in late Miocene rocks. The youngest faults are north-striking normal and northeast-striking left-lateral oblique-slip faults that cut Pliocene-Pleistocene rocks. Numerous hydrothermal systems were active during Miocene magmatism and formed extensive zones of hydrothermally altered rocks and several large mineral deposits, including gold- and silver-rich veins in the Bodie and Aurora mining districts (Vikre and others, in press).

78 FR 46117 - National Tunnel Inspection Standards

Science.gov (United States)

2013-07-30

... busiest vehicular tunnel in the world. The Fort McHenry Tunnel handles a daily traffic volume of more than... vehicular, transit, and rail tunnels in the New York City metropolitan area. Although it is still too early... congestion along alternative routes, and save users both dollars and fuel. If these tunnels were closed due...

Tunneling magnetoresistance and electroresistance in Fe/PbTiO{sub 3}/Fe multiferroic tunnel junctions

Energy Technology Data Exchange (ETDEWEB)

Dai, Jian-Qing, E-mail: djqkust@sina.com [School of Materials Science and Engineering, Kunming University of Science and Technology, Kunming 650093 (China)

2016-08-21

We perform first-principles electronic structure and spin-dependent transport calculations for a Fe/PbTiO{sub 3}/Fe multiferroic tunnel junction with asymmetric TiO{sub 2}- and PbO-terminated interfaces. We demonstrate that the interfacial electronic reconstruction driven by the in situ screening of ferroelectric polarization, in conjunction with the intricate complex band structure of barrier, play a decisive role in controlling the spin-dependent tunneling. Reversal of ferroelectric polarization results in a transition from insulating to half-metal-like conducting state for the interfacial Pb 6p{sub z} orbitals, which acts as an atomic-scale spin-valve by releasing the tunneling current in antiparallel magnetization configuration as the ferroelectric polarization pointing to the PbO-terminated interface. This effect produces large change in tunneling conductance. Our results open an attractive avenue in designing multiferroic tunnel junctions with excellent performance by exploiting the interfacial electronic reconstruction originated from the in situ screening of ferroelectric polarization.

Tunnel nitrogen spill experiment

International Nuclear Information System (INIS)

Ageyev, A.I.; Alferov, V.N.; Mulholland, G.T.

1983-01-01

The Energy Saver Safety Analysis Report (SAR) found the tunnel oxygen deficiency considerations emphasized helium spills. These reports concluded the helium quickly warms and because of its low denisty, rises to the apex of the tunnel. The oxygen content below the apex and in all but the immediate vicinity of the helium spill is essentially unchanged and guarantees an undisturbed source of oxygen especially important to fallen personnel. In contrast nitrogen spills warm slower than helium due to the ratio of the enthalpy changes per unit volume spilled spread more uniformly across the tunnel cross-section when warmed because of the much smaller density difference with air, and generally provides a greater hazard than helium spills as a result. In particular there was concern that personnel that might fall to the floor for oxygen deficiency or other reasons might find less, and not more, oxygen with dire consequences. The SAR concluded tunnel nitrogen spills were under-investigated and led to this work

New generation of free-piston shock tunnels

Science.gov (United States)

Morrison, W. R. B.; Stalker, R. J.; Duffin, J.

1990-01-01

Consideration is given to three free-piston driven hypersonic tunnels under construction that will greatly enhance existing test capabilities. The tunnel being built at Caltech will feature energy capabilities about 40 percent higher than those of the world's largest operational free-piston tunnel to date. The second tunnel under construction will allow full-size engine hardware at near-orbital speeds. The third facility is a high-performance expansion tube that will be capable of generating high enthalpy flows at speeds of up to 9 km/sec. It will provide flows with dissociation levels much lower than are attainable with a reflected shock tunnel, approaching actual flight conditions. A table shows the tunnels' characteristics.

Geological Prediction Ahead of Tunnel Face in the Limestone Formation Tunnel using Multi-Modal Geophysical Surveys

Science.gov (United States)

Zaki, N. F. M.; Ismail, M. A. M.; Hazreek Zainal Abidin, Mohd; Madun, Aziman

2018-04-01

Tunnel construction in typical karst topography face the risk which unknown geological condition such as abundant rainwater, ground water and cavities. Construction of tunnel in karst limestone frequently lead to potentially over-break of rock formation and cause failure to affected area. Physical character of limestone which consists large cavity prone to sudden failure and become worsen due to misinterpretation of rock quality by engineer and geologists during analysis stage and improper method adopted in construction stage. Consideration for execution of laboratory and field testing in rock limestone should be well planned and arranged in tunnel construction project. Several tests including Ground Penetration Radar (GPR) and geological face mapping were studied in this research to investigate the performances of limestone rock in tunnel construction, measured in term of rock mass quality that used for risk assessment. The objective of this study is to focus on the prediction of geological condition ahead of tunnel face using short range method (GPR) and verified by geological face mapping method to determine the consistency of actual geological condition on site. Q-Value as the main indicator for rock mass classification was obtained from geological face mapping method. The scope of this study is covering for tunnelling construction along 756 meters in karst limestone area which located at Timah Tasoh Tunnel, Bukit Tebing Tinggi, Perlis. For this case study, 15% of GPR results was identified as inaccurate for rock mass classification in which certain chainage along this tunnel with 34 out of 224 data from GPR was identified as incompatible with actual face mapping.

D Modelling of Tunnel Excavation Using Pressurized Tunnel Boring Machine in Overconsolidated Soils

Science.gov (United States)

Demagh, Rafik; Emeriault, Fabrice

2013-06-01

The construction of shallow tunnels in urban areas requires a prior assessment of their effects on the existing structures. In the case of shield tunnel boring machines (TBM), the various construction stages carried out constitute a highly three-dimensional problem of soil/structure interaction and are not easy to represent in a complete numerical simulation. Consequently, the tunnelling- induced soil movements are quite difficult to evaluate. A 3D simulation procedure, using a finite differences code, namely FLAC3D, taking into account, in an explicit manner, the main sources of movements in the soil mass is proposed in this paper. It is illustrated by the particular case of Toulouse Subway Line B for which experimental data are available and where the soil is saturated and highly overconsolidated. A comparison made between the numerical simulation results and the insitu measurements shows that the 3D procedure of simulation proposed is relevant, in particular regarding the adopted representation of the different operations performed by the tunnel boring machine (excavation, confining pressure, shield advancement, installation of the tunnel lining, grouting of the annular void, etc). Furthermore, a parametric study enabled a better understanding of the singular behaviour origin observed on the ground surface and within the solid soil mass, till now not mentioned in the literature.

Comparison of Genetic Algorithm and Hill Climbing for Shortest Path Optimization Mapping

Directory of Open Access Journals (Sweden)

Fronita Mona

2018-01-01

Full Text Available Traveling Salesman Problem (TSP is an optimization to find the shortest path to reach several destinations in one trip without passing through the same city and back again to the early departure city, the process is applied to the delivery systems. This comparison is done using two methods, namely optimization genetic algorithm and hill climbing. Hill Climbing works by directly selecting a new path that is exchanged with the neighbour’s to get the track distance smaller than the previous track, without testing. Genetic algorithms depend on the input parameters, they are the number of population, the probability of crossover, mutation probability and the number of generations. To simplify the process of determining the shortest path supported by the development of software that uses the google map API. Tests carried out as much as 20 times with the number of city 8, 16, 24 and 32 to see which method is optimal in terms of distance and time computation. Based on experiments conducted with a number of cities 3, 4, 5 and 6 producing the same value and optimal distance for the genetic algorithm and hill climbing, the value of this distance begins to differ with the number of city 7. The overall results shows that these tests, hill climbing are more optimal to number of small cities and the number of cities over 30 optimized using genetic algorithms.

Tunneling Flight Time, Chemistry, and Special Relativity.

Science.gov (United States)

Petersen, Jakob; Pollak, Eli

2017-09-07

Attosecond ionization experiments have not resolved the question "What is the tunneling time?". Different definitions of tunneling time lead to different results. Second, a zero tunneling time for a material particle suggests that the nonrelativistic theory includes speeds greater than the speed of light. Chemical reactions, occurring via tunneling, should then not be considered in terms of a nonrelativistic quantum theory calling into question quantum dynamics computations on tunneling reactions. To answer these questions, we define a new experimentally measurable paradigm, the tunneling flight time, and show that it vanishes for scattering through an Eckart or a square barrier, irrespective of barrier length or height, generalizing the Hartman effect. We explain why this result does not lead to experimental measurement of speeds greater than the speed of light. We show that this tunneling is an incoherent process by comparing a classical Wigner theory with exact quantum mechanical computations.

Geology of the hills in the region of the City of Santiago de Chile: New isotopic constraints

International Nuclear Information System (INIS)

Vergara, M; Lopez-Escobar, I; Palma, J.L; Hickey-Vargas, R

2001-01-01

Geological, geochronological and geochemical data demonstrate that the area where the city of Santiago de Chile is established used to be a huge volcanic field. At present, it is possible to distinguish in the area at least three volcanic cycles, which are geographically superimposed and deeply eroded. The first is Oligocene in age, the second Lower to Middle Miocene and the third is Middle to Upper Miocene. The Oligocene cycle is represented by volcanic and volcanoclastic rocks of the Provincia-San Ramon-Abanico and Conchali belts, and welded tuffs of the San Cristobal and Renca hills. The Lower to Middle Miocene cycle consists of subvolcanic rocks, mostly of basaltic to basaltic-andesite composition, characterized by the presence of clino- and orthopyroxene. The Middle to Upper Miocene cycle is composed predominantly of amphibole-bearing subvolcanic rocks of dacitic composition. The latter are found at the Manquehue hill, which limits the northern part of the city, and the hills at the Rinconada de Conchali. In this communication, we present new Sr-, Nd- and Pb- isotope data obtained from two subvolcanic samples of basaltic composition collected from the San Cristobal hill and at the Santa Lucia hill (Lower to Middle Miocene) and one amphibole-bearing subvolcanic sample of dacitic composition from the Manquehue hill (Middle to Upper Miocene) (au)

Tunnel Face Stability & New CPT Applications

NARCIS (Netherlands)

Broere, W.

2001-01-01

Nearly all tunnels bored in soft soils have encountered problems with the stability of the tunnel face. In several cases these problems led to an extended stand-still of the boring process. A better understanding of the face stability, and of the soil conditions around the tunnel boring machine, can

Shaft and tunnel sealing considerations

International Nuclear Information System (INIS)

Kelsall, P.C.; Shukla, D.K.

1980-01-01

Much of the emphasis of previous repository sealing research has been placed on plugging small diameter boreholes. It is increasingly evident that equal emphasis should now be given to shafts and tunnels which constitute more significant pathways between a repository and the biosphere. The paper discusses differences in requirements for sealing shafts and tunnels as compared with boreholes and the implications for seal design. Consideration is given to a design approach for shaft and tunnel seals based on a multiple component design concept, taking into account the requirements for retrievability of the waste. A work plan is developed for the future studies required to advance shaft and tunnel sealing technology to a level comparable with the existing technology for borehole sealing

Meteorological observations in support of a hill cap cloud experiment

Energy Technology Data Exchange (ETDEWEB)

Nielsen, Morten

1998-06-01

Humid air flows form a hill cap cloud over the Agana mountain ridge in the north-east of Tenerife. The HILLCLOUD project utilised this cloud formation to investigate the chemical and physical properties of cloud aerosols by land based observations. The project was part of the second Aerosol characterisation Experiment (ACE-2) of the International Global Atmospheric chemistry project (IGAC). The present report describes meteorological observations in support of the hill cap cloud experiment. Time-series of wind speed, wind direction, temperature and humidity were collected at ground-based meteorological stations during a period starting one year in advance of the main campaign. A series of radiosonde detecting the upstream stability and wind profile were launched during the main campaign. (au) 5 tabs., 32 ills., 6 refs.

Computational Multiqubit Tunnelling in Programmable Quantum Annealers

Science.gov (United States)

2016-08-25

ARTICLE Received 3 Jun 2015 | Accepted 26 Nov 2015 | Published 7 Jan 2016 Computational multiqubit tunnelling in programmable quantum annealers...state itself. Quantum tunnelling has been hypothesized as an advantageous physical resource for optimization in quantum annealing. However, computational ...qubit tunnelling plays a computational role in a currently available programmable quantum annealer. We devise a probe for tunnelling, a computational

Evaluation of the Influence Caused by Tunnel Construction on Groundwater Environment: A Case Study of Tongluoshan Tunnel, China

Directory of Open Access Journals (Sweden)

Jian Liu

2015-01-01

Full Text Available Problems related to water inflow during tunnel construction are challenging to designers, workers, and management departments, as they can threaten tunneling project from safety, time, and economic aspects. Identifying the impacts on groundwater environment resulting from tunnel drainage and making a correct assessment before tunnel construction is essential to better understand troubles that would be encountered during tunnel excavation and helpful to adopt appropriate countermeasures to minimize the influences. This study presents an indicator system and quantifies each indicator of Tongluoshan tunnel, which is located in southwest China with a length of 5.2 km and mainly passes through carbonate rocks and sandstones, based on field investigation and related technological reports. Then, an evaluation is made using fuzzy comprehensive assessment method, with a result showing that it had influenced the local groundwater environment at a moderate degree. Information fed back from environmental investigation and hydrologic monitoring carried out during the main construction period proves the evaluation, as the flow of some springs and streams located beside the tunnel route was found experiencing an apparent decline.

Investigation into scanning tunnelling luminescence microscopy

International Nuclear Information System (INIS)

Manson-Smith, S.K.

2001-01-01

This work reports on the development of a scanning tunnelling luminescence (STL) microscope and its application to the study of Ill-nitride semiconductor materials used in the production of light emitting devices. STL microscopy is a technique which uses the high resolution topographic imaging capabilities of the scanning tunnelling microscope (STM) to generate high resolution luminescence images. The STM tunnelling current acts as a highly localised source of electrons (or holes) which generates luminescence in certain materials. Light generated at the STM tunnelling junction is collected concurrently with the height variation of the tunnelling probe as it is scanned across a sample surface, producing simultaneous topographic and luminescence images. Due to the very localised excitation source, high resolution luminescence images can be obtained. Spectroscopic resolution can be obtained by using filters. Additionally, the variation of luminescence intensity with tunnel current and with bias voltage can provide information on recombination processes and material properties. The design and construction of a scanning tunnelling luminescence microscope is described in detail. Operating under ambient conditions, the microscope has several novel features, including a new type of miniature inertial slider-based approach motor, large solid-angle light collection optical arrangement and a tip-height regulation system which requires the minimum of operator input. (author)

Proceedings of the meeting on tunneling reaction and low temperature chemistry, 97 October. Tunneling reaction and quantum medium

Energy Technology Data Exchange (ETDEWEB)

Miyazaki, Tetsuo; Aratono, Yasuyuki; Ichikawa, Tsuneki; Shiotani, Masaru [eds.

1998-02-01

Present report is the proceedings of the 3rd Meeting on Tunneling Reaction and Low Temperature Chemistry held in Oct. 13 and 14, 1997. The main subject of the meeting is `Tunneling Reaction and Quantum Medium`. In the meeting, the physical and chemical phenomena in the liquid helium such as quantum nucleation, spectroscopy of atoms and molecules, and tunneling abstraction reaction of tritium atom were discussed as the main topics as well as the tunneling reactions in the solid hydrogen and organic compounds. Through the meetings held in 1995, 1996, and 1997, the tunneling phenomena proceeding at various temperatures (room temperature to mK) in the wide fields of chemistry, biology, and physics were discussed intensively and the importance of the tunneling phenomena in the science has been getting clear. The 12 of the presented papers are indexed individually. (J.P.N.)

Proceedings of the meeting on tunneling reaction and low temperature chemistry, 97 October. Tunneling reaction and quantum medium

International Nuclear Information System (INIS)

Miyazaki, Tetsuo; Aratono, Yasuyuki; Ichikawa, Tsuneki; Shiotani, Masaru

1998-02-01

Present report is the proceedings of the 3rd Meeting on Tunneling Reaction and Low Temperature Chemistry held in Oct. 13 and 14, 1997. The main subject of the meeting is 'Tunneling Reaction and Quantum Medium'. In the meeting, the physical and chemical phenomena in the liquid helium such as quantum nucleation, spectroscopy of atoms and molecules, and tunneling abstraction reaction of tritium atom were discussed as the main topics as well as the tunneling reactions in the solid hydrogen and organic compounds. Through the meetings held in 1995, 1996, and 1997, the tunneling phenomena proceeding at various temperatures (room temperature to mK) in the wide fields of chemistry, biology, and physics were discussed intensively and the importance of the tunneling phenomena in the science has been getting clear. The 12 of the presented papers are indexed individually. (J.P.N.)

Tunneling anisotropic magnetoresistance in Co/AIOx/Al tunnel junctions with fcc Co (111) electrodes

NARCIS (Netherlands)

Wang, Kai; Tran, T. Lan Ahn; Brinks, Peter; Brinks, P.; Sanderink, Johannes G.M.; Bolhuis, Thijs; van der Wiel, Wilfred Gerard; de Jong, Machiel Pieter

2013-01-01

Tunneling anisotropic magnetoresistance (TAMR) has been characterized in junctions comprised of face-centered cubic (fcc) Co (111) ferromagnetic electrodes grown epitaxially on sapphire substrates, amorphous AlOx tunnel barriers, and nonmagnetic Al counterelectrodes. Large TAMR ratios have been

Mechanical stability of repository tunnels and factors to be considered for determining tunnel spacing

International Nuclear Information System (INIS)

Takeuchi, Kunifumi

1994-01-01

Kristallin-1 organized by Nagra is currently advanced as a synthetic project regarding a high level radioactive waste (HLW) repository in Switzerland. Its host rock is granitic rocks, and the potential siting area is located in northern Switzerland. The objective of this project is to demonstrate the long term safety of a HLW repository under more site-specific conditions than before. As the detailed geological data were investigated, the average size of undisturbed crystalline rock blocks is limited horizontally to about several hundred meter, therefore, the HLW repository area must be divided into several panels to avoid fracture zones. It is necessary to make tunnel spacing as small as possible for the purpose of reasonably designing the entire layout of repository tunnels. The main factors to be considered for determining repository tunnel spacing are listed. Rock mass modeling, rock mass material properties, the analysis model and parameters, the numerical analysis of repository tunnel stability and its main conclusion are reported. The numerical analysis of the temperature distribution in near field was carried out. Tunnel spacing should be set more than 20 m in view of the maximum temperature. (K.I.)

Resonance tunneling electron-vibrational spectroscopy of polyoxometalates.

Science.gov (United States)

Dalidchik, F I; Kovalevskii, S A; Balashov, E M

2017-05-21

The tunneling spectra of the ordered monolayer films of decamolybdodicobaltate (DMDC) compounds deposited from aqueous solutions on HOPG were measured by scanning tunnel microscopy in air. The DMDC spectra, as well as the tunneling spectra of other polyoxometalates (POMs), exhibit well-defined negative differential resistances (NDRs). The mechanism of formation of these spectral features was established from the collection of revealed NDR dependences on the external varying parameters and found to be common to all systems exhibiting Wannier-Stark localization. A model of biresonance tunneling was developed to provide an explanation for the totality of experimental data, both the literature and original, on the tunneling POM probing. A variant of the tunneling electron-vibrational POM spectroscopy was proposed allowing the determination of the three basic energy parameters-energy gaps between the occupied and unoccupied states, frequencies of the vibrational transitions accompanying biresonance electron-tunneling processes, and electron-vibrational interaction constants on the monomolecular level.

Current noise in tunnel junctions

Energy Technology Data Exchange (ETDEWEB)

Frey, Moritz; Grabert, Hermann [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Strasse 3, 79104, Freiburg (Germany)

2017-06-15

We study current fluctuations in tunnel junctions driven by a voltage source. The voltage is applied to the tunneling element via an impedance providing an electromagnetic environment of the junction. We use circuit theory to relate the fluctuations of the current flowing in the leads of the junction with the voltage fluctuations generated by the environmental impedance and the fluctuations of the tunneling current. The spectrum of current fluctuations is found to consist of three parts: a term arising from the environmental Johnson-Nyquist noise, a term due to the shot noise of the tunneling current and a third term describing the cross-correlation between these two noise sources. Our phenomenological theory reproduces previous results based on the Hamiltonian model for the dynamical Coulomb blockade and provides a simple understanding of the current fluctuation spectrum in terms of circuit theory and properties of the average current. Specific results are given for a tunnel junction driven through a resonator. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Anomalous Tunnel Magnetoresistance and Spin Transfer Torque in Magnetic Tunnel Junctions with Embedded Nanoparticles

Science.gov (United States)

Useinov, Arthur; Ye, Lin-Xiu; Useinov, Niazbeck; Wu, Te-Ho; Lai, Chih-Huang

2015-01-01

The tunnel magnetoresistance (TMR) in the magnetic tunnel junction (MTJ) with embedded nanoparticles (NPs) was calculated in range of the quantum-ballistic model. The simulation was performed for electron tunneling through the insulating layer with embedded magnetic and non-magnetic NPs within the approach of the double barrier subsystem connected in parallel to the single barrier one. This model can be applied for both MTJs with in-plane magnetization and perpendicular one. We also calculated the in-plane component of the spin transfer torque (STT) versus the applied voltage in MTJs with magnetic NPs and determined that its value can be much larger than in single barrier system (SBS) for the same tunneling thickness. The reported simulation reproduces experimental data of the TMR suppression and peak-like TMR anomalies at low voltages available in leterature. PMID:26681336

A 2D analytical cylindrical gate tunnel FET (CG-TFET) model: impact of shortest tunneling distance

Science.gov (United States)

Dash, S.; Mishra, G. P.

2015-09-01

A 2D analytical tunnel field-effect transistor (FET) potential model with cylindrical gate (CG-TFET) based on the solution of Laplace’s equation is proposed. The band-to-band tunneling (BTBT) current is derived by the help of lateral electric field and the shortest tunneling distance. However, the analysis is extended to obtain the subthreshold swing (SS) and transfer characteristics of the device. The dependency of drain current, SS and transconductance on gate voltage and shortest tunneling distance is discussed. Also, the effect of scaling the gate oxide thickness and the cylindrical body diameter on the electrical parameters of the device is analyzed.

A 2D analytical cylindrical gate tunnel FET (CG-TFET) model: impact of shortest tunneling distance

International Nuclear Information System (INIS)

Dash, S; Mishra, G P

2015-01-01

A 2D analytical tunnel field-effect transistor (FET) potential model with cylindrical gate (CG-TFET) based on the solution of Laplace’s equation is proposed. The band-to-band tunneling (BTBT) current is derived by the help of lateral electric field and the shortest tunneling distance. However, the analysis is extended to obtain the subthreshold swing (SS) and transfer characteristics of the device. The dependency of drain current, SS and transconductance on gate voltage and shortest tunneling distance is discussed. Also, the effect of scaling the gate oxide thickness and the cylindrical body diameter on the electrical parameters of the device is analyzed. (paper)

Stratigraphy and paleontology of fossil hill Peninsula Fildes, Rey Jorge island, Antarctica: a new approach

International Nuclear Information System (INIS)

Perea, D.; Masquelin, H.; Verde, M.; Guerequiz, R.

1998-01-01

Results of the first Uruguayan paleontologic and biostratigraphical investigations in Antarctica are presented.The field work was performed in Fildes Peninsula, King George Island, near the Uruguayan station Base Cientifica Antartida Artigas. Some fossiliferous outcrops were geologic and pale ontologically analyzed, among them the Fossil Hill, placed in the middle part of the peninsula, in front of Ardley Island between the Chinese and Chilean stations. This hill is composed of fossil bearing piroclastic and epiclastic rocks, assigned to the Fossil Hill Fm.Vegetal remains (petrified wood and leaf impronts)were observed and collected in this unit and it is remarkable the presence of Nothofagus sp. and invertebrate trace fossils Cochlichnus isp and Helminthopsis isp.

Lithium in Jack Hills zircons: Evidence for extensive weathering of Earth's earliest crust

Science.gov (United States)

Ushikubo, Takayuki; Kita, Noriko T.; Cavosie, Aaron J.; Wilde, Simon A.; Rudnick, Roberta L.; Valley, John W.

2008-08-01

In situ Li analyses of 4348 to 3362 Ma detrital zircons from the Jack Hills, Western Australia by SIMS reveal that the Li abundances (typically 10 to 60 ppm) are commonly over 10,000 times higher than in zircons crystallized from mantle-derived magmas and in mantle-derived zircon megacrysts (typically Jack Hills zircons also have fractionated lithium isotope ratios ( δ7Li = - 19 to + 13‰) about five times more variable than those recorded in primitive ocean floor basalts (2 to 8‰), but similar to continental crust and its weathering products. Values of δ7Li below - 10‰ are found in zircons that formed as early as 4300 Ma. The high Li compositions indicate that primitive magmas were not the source of Jack Hills zircons and the fractionated values of δ7Li suggest that highly weathered regolith was sampled by these early Archean magmas. These new Li data provide evidence that the parent magmas of ancient zircons from Jack Hills incorporated materials from the surface of the Earth that interacted at low temperature with liquid water. These data support the hypothesis that continental-type crust and oceans existed by 4300 Ma, within 250 million years of the formation of Earth and the low values of δ7Li suggest that weathering was extensive in the early Archean.

Instabilities in thin tunnel junctions

International Nuclear Information System (INIS)

Konkin, M.K.; Adler, J.G.

1978-01-01

Tunnel junctions prepared for inelastic electron tunneling spectroscopy are often plagued by instabilities in the 0-500-meV range. This paper relates the bias at which the instability occurs to the barrier thickness

ACCOMMODATION INFRASTRUCTURE AND TOURISM FLOWS ON FELEACU HILL (CLUJ COUNTY

Directory of Open Access Journals (Sweden)

DANIELA-LIVIA GHEORGHIEȘ

2016-06-01

Full Text Available Accommodation Infrastructure and Tourism Flows on Feleacu Hill (Cluj County. Feleacu Hill experienced tourism development between 2001 and 2015. The INS data indicates that the number of accommodation units increased from one (2001 to four (2015 and there are a few more which are not registered in the INS database. The accommodation capacity increases, as many guesthouses are expanding their premises to receive more tourists and new accommodation units emerge, such as Hotel Premier in Vâlcele (Feleacu commune. Tourism flows also registered a highly positive trend. The number of arrivals increased from 95 tourists in 2002 to 7791 tourists in 2015. However, there was a downturn between 2009 and 2012, due to the economic crisis and the opening of the Turda – Gilău motorway (A3, which redirected transit routes outside the region and led to the closure of Paradis Hotel in 2012. Since 2012, the number of arrivals and overnight stays increased steadily due to the development of new forms of tourism – rural tourism, agrotourism, extreme tourism and complex tourism, materialized in growing numbers of tourists at the two guesthouses in Ciurila commune (“La Mesteceni” and “Domeniul Regilor”. Tourism brings obvious benefits to the rural communities on Feleacu Hill, even if the average duration of stay is still low.

An injector for the proposed Berkeley Ultrafast X-Ray Light Source

International Nuclear Information System (INIS)

Lidia, Steven; Corlett, John; Pusina, Jan; Staples, John; Zholents, Alexander

2003-01-01

Berkeley Lab has proposed to build a recirculating linac based X-ray source for ultra-fast dynamic studies [1]. This machine requires a flat electron beam with a small vertical emittance and large x/y emittance ratio to allow for compression of spontaneous undulator emission of soft and hard x-ray pulses, and a low-emittance, round electron beam for coherent emission of soft x-rays via the FEL process based on cascaded harmonic generation [2]. We propose an injector system consisting of two high gradient high repetition rate photo cathode guns [3] (one for each application), an ∼120 MeV super conducting linear accelerator, a 3rd harmonic cavity for linearization of the longitudinal phase space, and a bunch compressor. We present details of the design and the results of particle tracking studies using several computer codes

Tunneling time in fluctuating symmetric double wells: Suppression and enhancement of tunneling by spatial symmetry-preserving perturbations

International Nuclear Information System (INIS)

Kar, Susmita; Bhattacharyya, S.P.

2011-01-01

Graphical abstract: Spatial symmetry-preserving sinusoidal fluctuations of symmetric double-well parameters cause enhancement of tunneling at ω ∼ ω 0 while rectified sinusoidal fluctuations suppress it at ω∼(ω 0 )/2 . Research highlights: → Spatial symmetry-preserving sinusoidal and rectified sinusoidal fluctuations of symmetrical double-well parameters have contrasting effects on tunneling. → Sinusoidal fluctuations at frequency ω ∼ ω 0 causes resonance enhancement of tunneling, ω 0 being the 0 + ↔ 1 + transition frequency. → Under rectified sinusoidal fluctuations at a frequency ω∼1/2 ω 0 suppression or coherent destruction of tunneling is observed due to barrier localization. → The observations are explained by energy-gain analysis and analysis of the time-dependent overlap amplitudes. - Abstract: We investigate how tunneling-time gets affected by spatial symmetry preserving fluctuations in the parameters determining the width, barrier height and well-depth of a symmetric double-well potential. Sinusoidal and rectified sinusoidal fluctuations of the well-parameters are shown to have contrasting effects. Significant enhancement of tunneling is noticed when the well-parameters fluctuate sinusoidally with frequency ω ∼ ω 0 while under rectified sinusoidal perturbation, quenching of tunneling takes place at a fluctuation frequency ω∼1/2 ω 0 ,ω 0 , being the frequency of the lowest transition allowed by the fluctuation induced spatial perturbation of even parity. Time-dependent Hellmann-Feynman theorem is invoked to analyze the energy changes induced by fluctuations. It turns out that the enhancement of tunneling in the sinusoidally fluctuating double well at frequency ω ∼ ω 0 is caused by transition to 1 ± levels under the barrier while in the rectified sinusoidal field at ω∼1/2 ω 0 , a two-photon like process suppresses the tunneling by inducing barrier localization.

The proterozoic Georgetown Province - a Broken Hill analogue

International Nuclear Information System (INIS)

Carr, G.R.

2000-01-01

Collaborative work between CSIRO and AGSO has resulted in the development of a Pb isotope model that attempts to place relatively precise (∼5 Ma) age constraints on Proterozoic mineralisation in the Mount Isa and McArthur River terrains (Sun et al., 1994). Although this model was developed for sediment hosted mineralisation in low grade metamorphic terrains, the CSIRO-AGSO model ages for other mineralisation in high-grade terrains such as Broken Hill appear to be consistent with the U-Pb zircon ages obtained for the high-grade host sequences. Without independent evidence that the model is applicable to such terrains, the observations cannot be used to indicate the age of the mineralisation. Lead isotope data obtained on potassium feldspar separates from five felsic intrusive samples in the Georgetown terrain show a wide range of Pb isotope ratios. The lowest 206 Pb/ 204 Pb analyses are considered to approximate to the Proterozoic initial ratio and indicate a model age of ∼1510 Ma based on the CSIRO-AGSO model. This age is 45 Ma younger than the crystallisation age of the granite, but must be considered a minimum as the initial 206 Pb/ 204 Pb ratio may well prove to be lower after more comprehensive analysis. Sulfide mineralisation within the Einasleigh Metamorphics has a wide range of 206 Pb/ 204 Pb ratios that lie between this granite value and the relatively homogeneous population from Railway Flat. The Railway Flat data are very similar to values for Broken Hill and also the Broken Hill-type Pegmont mineralisation in the Mount Isa Eastern Succession. These data all have significantly lower 207 Pb/ 204 Pb ratios than the CSIRO-AGSO model, suggesting a significantly different source rock environment for this style of mineralisation from that for the sediment hosted deposits

On the numerical treatment of the Griffin-Hill-Eheeler equation

International Nuclear Information System (INIS)

Galleti, D.; Toledo Piza, A.F.R.

The precision attainable in the numerical treatment of the Griffin-Hill-Wheeler equation is studied in a solvable model. Trucation errors related to the generator coordinate kinematics are exhibited and briefly discussed [pt

Tunnelling in Dante's Inferno

Energy Technology Data Exchange (ETDEWEB)

Furuuchi, Kazuyuki [Manipal Centre for Natural Sciences, Manipal University, Dr.T.M.A. Pai Planetarium Building, Madhav Nagar, Manipal, Karnataka 576104 (India); Sperling, Marcus, E-mail: kazuyuki.furuuchi@manipal.edu, E-mail: marcus.sperling@univie.ac.at [Fakultät für Physik, Universität Wien, Boltzmanngasse 5, A-1090 Wien (Austria)

2017-05-01

We study quantum tunnelling in Dante's Inferno model of large field inflation. Such a tunnelling process, which will terminate inflation, becomes problematic if the tunnelling rate is rapid compared to the Hubble time scale at the time of inflation. Consequently, we constrain the parameter space of Dante's Inferno model by demanding a suppressed tunnelling rate during inflation. The constraints are derived and explicit numerical bounds are provided for representative examples. Our considerations are at the level of an effective field theory; hence, the presented constraints have to hold regardless of any UV completion.

Fire safety assessment of tunnel structures

DEFF Research Database (Denmark)

Gkoumas, Konstantinos; Giuliani, Luisa; Petrini, Francesco

2011-01-01

.g. structural and non structural, organizational, human behavior). This is even more truth for the fire safety design of such structures. Fire safety in tunnels is challenging because of the particular environment, bearing in mind also that a fire can occur in different phases of the tunnel’s lifecycle. Plans...... for upgrading fire safety provisions and tunnel management are also important for existing tunnels. In this study, following a brief introduction of issues regarding the above mentioned aspects, the structural performance of a steel rib for a tunnel infrastructure subject to fire is assessed by means...

Tunnelling in Dante's Inferno

International Nuclear Information System (INIS)

Furuuchi, Kazuyuki; Sperling, Marcus

2017-01-01

We study quantum tunnelling in Dante's Inferno model of large field inflation. Such a tunnelling process, which will terminate inflation, becomes problematic if the tunnelling rate is rapid compared to the Hubble time scale at the time of inflation. Consequently, we constrain the parameter space of Dante's Inferno model by demanding a suppressed tunnelling rate during inflation. The constraints are derived and explicit numerical bounds are provided for representative examples. Our considerations are at the level of an effective field theory; hence, the presented constraints have to hold regardless of any UV completion.

Tunneling path toward spintronics

International Nuclear Information System (INIS)

Miao Guoxing; Moodera, Jagadeesh S; Muenzenberg, Markus

2011-01-01

The phenomenon of quantum tunneling, which was discovered almost a century ago, has led to many subsequent discoveries. One such discovery, spin polarized tunneling, was made 40 years ago by Robert Meservey and Paul Tedrow (Tedrow and Meservey 1971 Phys. Rev. Lett. 26 192), and it has resulted in many fundamental observations and opened up an entirely new field of study. Until the mid-1990s, this field developed at a steady, low rate, after which a huge increase in activity suddenly occurred as a result of the unraveling of successful spin tunneling between two ferromagnets. In the past 15 years, several thousands of papers related to spin polarized tunneling and transport have been published, making this topic one of the hottest areas in condensed matter physics from both fundamental science and applications viewpoints. Many review papers and book chapters have been written in the past decade on this subject. This paper is not exhaustive by any means; rather, the emphases are on recent progress, technological developments and informing the reader about the current direction in which this topic is moving.

Aquatic assessment of the Pike Hill Copper Mine Superfund site, Corinth, Vermont

Science.gov (United States)

Piatak, Nadine M.; Argue, Denise M.; Seal, Robert R.; Kiah, Richard G.; Besser, John M.; Coles, James F.; Hammarstrom, Jane M.; Levitan, Denise M.; Deacon, Jeffrey R.; Ingersoll, Christopher G.

2013-01-01

The Pike Hill Copper Mine Superfund site in Corinth, Orange County, Vermont, includes the Eureka, Union, and Smith mines along with areas of downstream aquatic ecosystem impairment. The site was placed on the U.S. Environmental Protection Agency (USEPA) National Priorities List in 2004. The mines, which operated from about 1847 to 1919, contain underground workings, foundations from historical structures, several waste-rock piles, and some flotation tailings. The mine site is drained to the northeast by Pike Hill Brook, which includes several wetland areas, and to the southeast by an unnamed tributary that flows to the south and enters Cookville Brook. Both brooks eventually drain into the Waits River, which flows into the Connecticut River. The aquatic ecosystem at the site was assessed using a variety of approaches that investigated surface-water quality, sediment quality, and various ecological indicators of stream-ecosystem health. The degradation of surface-water quality is caused by elevated concentrations of copper, and to a lesser extent cadmium, with localized effects caused by aluminum, iron, and zinc. Copper concentrations in surface waters reached or exceeded the USEPA national recommended chronic water-quality criteria for the protection of aquatic life in all of the Pike Hill Brook sampling locations except for the location farthest downstream, in half of the locations sampled in the tributary to Cookville Brook, and in about half of the locations in one wetland area located in Pike Hill Brook. Most of these same locations also contained concentrations of cadmium that exceeded the chronic water-quality criteria. In contrast, surface waters at background sampling locations were below these criteria for copper and cadmium. Comparison of hardness-based and Biotic Ligand Model (BLM)-based criteria for copper yields similar results with respect to the extent or number of stations impaired for surface waters in the affected area. However, the BLM

Solar heating and hot water system installed at Cherry Hill, New Jersey. [Hotels

Energy Technology Data Exchange (ETDEWEB)

1979-05-16

The solar heating and hot water system installed in existing buildings at the Cherry Hill Inn in Cherry Hill, New Jersey is described in detail. The system went into operation November 8, 1978 and is expected to furnish 31.5% of the overall heating load and 29.8% of the hot water load. The collectors are General Electric Company liquid evacuated tube type. The storage system is an above ground insulated steel water tank with a capacity of 7,500 gallons.

The effects of the introduction of the no-smoking policy at HMYOI Warren Hill on bullying behaviour.

Science.gov (United States)

Lawrence, Sally; Welfare, Heather

2008-01-01

The current research explores the prevalence of bullying behaviour at HMYOI Warren Hill and the Carlford Unit. The introduction of the no-smoking policy at the establishment was also explored in relation to its effect on bullying behaviour given that tobacco has historically been the main item that young people have been bullied for. The Direct and Indirect Prisoner behaviour Checklist--Revised (DIPC-R) and a questionnaire designed to identify the effect of the introduction of the no-smoking policy on bullying behaviour were used within this study to answer the following questions: what is the prevalence of bullying behaviour at Warren Hill and the Carlford Unit, and do young people at Warren Hill and the Carlford Unit think that the rate and nature of bullying has been affected by the introduction of the no-smoking policy? One hundred and fifteen young people took part in the study. At Warren Hill, Bully/Victims were the most prevalent type identified and this was significantly greater than the number of young people identified as Pure Victims or Not Involved. On the Carlford Unit, Not Involved was the most prevalent type identified, and this finding provides limited support for the theories of bullying behaviour identified within the present study. The study found that the rate of bullying decreased following the introduction of the no-smoking policy at Warren Hill. The findings from this study are being used in the development of a new Violence Reduction Policy at HMYOI Warren Hill.

Lithostratigraphy of the Calico Hills Formation and Prow Pass Tuff (Crater Flat Group) at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Moyer, T.C.; Geslin, J.K.

1995-01-01

Lithostratigraphic relations within the Calico Hills Formation and Prow Pass Tuff (Crater Flat Group) were reconstructed from analysis of core samples and observation of outcrop exposures. The Calico Hills Formation is composed of five nonwelded pyroclastic units (each formed of one or more pyroclastic-flow deposits) that overlie an interval of bedded tuff and a basal volcaniclastic sandstone unit. The Prow Pass Tuff is divided into four pyroclastic units and an underlying interval of bedded tuff. The pyroclastic units of the Prow Pass Tuff are distinguished by the sizes and amounts of their pumice and lithic clasts and their degree of welding. Pyroclastic units of the Prow Pass Tuff are distinguished from those of the Calico Hills Formation by their phenocryst assemblage, chemical composition, and ubiquitous siltstone lithic clasts. Downhole resistivity tends to mirror the content of authigenic minerals, primarily zeolites, in both for-mations and may be useful for recognizing the vitric-zeolite boundary in the study area. Maps of zeolite distribution illustrate that the bedded tuff and basal sandstone units of the Calico Hills Formation are altered over a wider area than the pyroclastic units of both the Calico Hills Formation and the upper Prow Pass Tuff

Lithostratigraphy of the Calico Hills Formation and Prow Pass Tuff (Crater Flat Group) at Yucca Mountain, Nevada

Energy Technology Data Exchange (ETDEWEB)

Moyer, T.C.; Geslin, J.K. [Science Applications International Corp., Las Vegas, NV (United States)

1995-07-01

Lithostratigraphic relations within the Calico Hills Formation and Prow Pass Tuff (Crater Flat Group) were reconstructed from analysis of core samples and observation of outcrop exposures. The Calico Hills Formation is composed of five nonwelded pyroclastic units (each formed of one or more pyroclastic-flow deposits) that overlie an interval of bedded tuff and a basal volcaniclastic sandstone unit. The Prow Pass Tuff is divided into four pyroclastic units and an underlying interval of bedded tuff. The pyroclastic units of the Prow Pass Tuff are distinguished by the sizes and amounts of their pumice and lithic clasts and their degree of welding. Pyroclastic units of the Prow Pass Tuff are distinguished from those of the Calico Hills Formation by their phenocryst assemblage, chemical composition, and ubiquitous siltstone lithic clasts. Downhole resistivity tends to mirror the content of authigenic minerals, primarily zeolites, in both for-mations and may be useful for recognizing the vitric-zeolite boundary in the study area. Maps of zeolite distribution illustrate that the bedded tuff and basal sandstone units of the Calico Hills Formation are altered over a wider area than the pyroclastic units of both the Calico Hills Formation and the upper Prow Pass Tuff.

Susceptibility of Shallow Landslide in Fraser Hill Catchment, Pahang Malaysia

Directory of Open Access Journals (Sweden)

Wan Nor Azmin Sulaiman

2010-01-01

Full Text Available In tropical areas especially during monsoon seasons intense precipitation is the main caused that trigger the natural shallow landslide phenomena. This phenomenon can be disastrous and widespread in occurrence even in undisturbed forested catchment. In this paper, an attempt has been made to evaluate the susceptibility of natural hill slopes to failure for a popular hill resort area, the Fraser Hill Catchment under different rainfall regimes and soil thickness. A Digital Elevation Model (DEM was prepared for the 8.2 km2 catchment. A GIS based deterministic model was then applied to predict the spatial landslide occurrence within catchment. Model input parameters include bulk density, friction angle, cohesion and hydraulic conductivity were gathered through in situ and lab analysis as well as from previous soil analysis records. Landslides locations were recorded using GPS as well as previous air photos and satellite imagery to establish landslide source areas inventory. The landslide susceptibility map was produced under different precipitation event’s simulation to see the effects of precipitation to stability of the hill slopes of the catchment. The results were categorized into naturally unstable (Defended, Upper Threshold, Lower Threshold, marginal instability (Quasi Stable and stable area (Moderately Stable and Stable. Results of the simulation indicated notable change in precipitation effect on Defended area is between 10mm to 40mm range in a single storm event. However, when storm event is exceeded 120mm, the result on Defended area produced by the model tends to be constant further on. For area categorized as naturally unstable (Factor of Safety, SF<1, with 110 mm of precipitation in a single storm event and soil depth at 2 meters and 4 meters could affect 69.51% and 69.88% respectively of the catchment area fall under that class. In addition, the model was able to detect 4% more of the landslide inventory under shallower soil depth of

Utilization of geothermal energy in tunnels driven by tunnel drilling machines; Nutzung von Geothermie in TBM vorgetriebenen Tunneln

Energy Technology Data Exchange (ETDEWEB)

Pralle, Norbert; Franzius, Jan-Niklas [Ed. Zueblin AG, Stuttgart (Germany). Zentrale Technik; Liebel, Volker [Rehau AG und Co, Erlangen (Germany)

2009-07-01

Tunnels are nowadays more and more often constructed by means of tunnel boring machines rather than by conventional tunnel excavation. This is because tunnel boring provides a greater degree of safety for neighbouring structures, especially when it takes place in near-surface unconsolidated rock. However, bored tunnels offer less favourable framework conditions for the exploitation of geothermal energy because they are usually lined with concrete tubbings. Depending on the tunnel's diameter this normally involves rings of 1 to 2 metres width made up of several concrete elements. Adapting this type of design for geothermal energy production requires the use of an absorber piping system which permits coupling between the individual concrete elements while at the same time meeting the strict geometric tolerances required for its installation. A system of this type has been developed in a cooperation between the Rehau AG +Co. and Ed. Zueblin AG (Central Technology Services). These energy tubbings have already been installed in two tunnel structures and have also been examined in laboratory tests. An extensive measurement programme is under preparation which is aimed at gaining insights for the further optimisation of energy tubbings.

Tunneling anisotropic magnetoresistance driven by magnetic phase transition.

Science.gov (United States)

Chen, X Z; Feng, J F; Wang, Z C; Zhang, J; Zhong, X Y; Song, C; Jin, L; Zhang, B; Li, F; Jiang, M; Tan, Y Z; Zhou, X J; Shi, G Y; Zhou, X F; Han, X D; Mao, S C; Chen, Y H; Han, X F; Pan, F

2017-09-06

The independent control of two magnetic electrodes and spin-coherent transport in magnetic tunnel junctions are strictly required for tunneling magnetoresistance, while junctions with only one ferromagnetic electrode exhibit tunneling anisotropic magnetoresistance dependent on the anisotropic density of states with no room temperature performance so far. Here, we report an alternative approach to obtaining tunneling anisotropic magnetoresistance in α'-FeRh-based junctions driven by the magnetic phase transition of α'-FeRh and resultantly large variation of the density of states in the vicinity of MgO tunneling barrier, referred to as phase transition tunneling anisotropic magnetoresistance. The junctions with only one α'-FeRh magnetic electrode show a magnetoresistance ratio up to 20% at room temperature. Both the polarity and magnitude of the phase transition tunneling anisotropic magnetoresistance can be modulated by interfacial engineering at the α'-FeRh/MgO interface. Besides the fundamental significance, our finding might add a different dimension to magnetic random access memory and antiferromagnet spintronics.Tunneling anisotropic magnetoresistance is promising for next generation memory devices but limited by the low efficiency and functioning temperature. Here the authors achieved 20% tunneling anisotropic magnetoresistance at room temperature in magnetic tunnel junctions with one α'-FeRh magnetic electrode.

Electron tunneling in chemistry

International Nuclear Information System (INIS)

Zamaraev, K.I.; Khajrutdinov, R.F.; Zhdanov, V.P.; Molin, Yu.N.

1985-01-01

Results of experimental and theoretical investigations are outlined systematically on electron tunnelling in chemical reactions. Mechanism of electron transport to great distances is shown to be characteristic to chemical compounds of a wide range. The function of tunnel reactions is discussed for various fields of chemistry, including radiation chemistry, electrochemistry, chemistry of solids, chemistry of surface and catalysis

Mixed waste certification plan for the Lawrence Berkeley Laboratory Hazardous Waste Handling Facility. Revision 1

International Nuclear Information System (INIS)

1995-01-01

The purpose of this plan is to describe the organization and methodology for the certification of mixed waste handled in the Hazardous Waste Handling Facility (HWHF) at Lawrence Berkeley Laboratory (LBL). This plan is composed to meet the requirements found in the Westinghouse Hanford Company (WHC) Solid Waste Acceptance Criteria (WAC) and follows the suggested outline provided by WHC in the letter of April 26, 1990, to Dr. R.H. Thomas, Occupational Health Division, LBL. Mixed waste is to be transferred to the WHC Hanford Site Central Waste Complex and Burial Grounds in Hanford, Washington

Signatures of unstable semiclassical trajectories in tunneling

International Nuclear Information System (INIS)

Levkov, D G; Panin, A G; Sibiryakov, S M

2009-01-01

It was found recently that processes of multidimensional tunneling are generally described at high energies by unstable semiclassical trajectories. We study two observational signatures related to the instability of trajectories. First, we find an additional power-law dependence of the tunneling probability on the semiclassical parameter as compared to the standard case of potential tunneling. The second signature is a substantial widening of the probability distribution over final-state quantum numbers. These effects are studied using a modified semiclassical technique which incorporates stabilization of the tunneling trajectories. The technique is derived from first principles. We obtain expressions for the inclusive and exclusive tunneling probabilities in the case of unstable semiclassical trajectories. We also investigate the 'phase transition' between the cases of stable and unstable trajectories across certain 'critical' values of energy. Finally, we derive the relation between the semiclassical probabilities of tunneling from the low-lying and highly excited initial states. This puts on firm ground a conjecture made previously in the semiclassical description of collision-induced tunneling in field theory

Disc Bit Abrasion Parameters in TBM Tunnelling regarded exemplarily for the Gotthard Base Tunnel

Directory of Open Access Journals (Sweden)

Edmund a Wax

2005-11-01

Full Text Available In this article the author presents Amund Bruland’s empirical approach to determine the disc bit abrasion of TBMs (Tunnel Boring Machines, transforms the respective empirical dependencies into approximated mathematical relations and verifies them exemplarily for the currently constructed Gotthard Base Tunnel.

Magnetic reconstruction induced magnetoelectric coupling and spin-dependent tunneling in Ni/KNbO_3/Ni multiferroic tunnel junctions

International Nuclear Information System (INIS)

Zhang, Hu; Dai, Jian-Qing; Song, Yu-Min

2016-01-01

We investigate the magnetoelectric coupling and spin-polarized tunneling in Ni/KNbO_3/Ni multiferroic tunnel junctions with asymmetric interfaces based on density functional theory. The junctions have two stable polarization states. We predict a peculiar magnetoelectric effect in such junctions originating from the magnetic reconstruction of Ni near the KO-terminated interface. This reconstruction is induced by the reversal of the ferroelectric polarization of KNbO_3. Furthermore, the change in the magnetic ordering filters the spin-dependent current. This effect leads to a change in conductance by about two orders of magnitude. As a result we obtain a giant tunneling electroresistance effect. In addition, there exist sizable tunneling magnetoresistance effects for two polarization states. - Highlights: • We study the ME coupling and electron tunneling in Ni/KNbO_3/Ni junctions. • There is magnetic reconstruction of Ni atoms near the KO-terminated interface. • A peculiar magnetoelectric coupling effect is obtained. • Predicted giant tunneling electroresistance effects.

Unified time analysis of photon and particle tunnelling

International Nuclear Information System (INIS)

Olkhovsky, V.S.; Recami, Erasmo; Jakiel, Jacek

2004-01-01

A unified time analysis of photon and nonrelativistic particle tunnellings is presented, in which time is regarded as a quantum observable, canonically conjugated to energy. Within this approach, one can introduce self-consistent definitions of the tunnelling times, on the basis of conventional quantum mechanics (or one-dimensional quantum electrodynamics) only. The validity of the Hartman effect [which states the tunnelling duration to be independent of the (opaque) barrier width, with superluminal group velocities of the tunnelling packet as a consequence] is verified for all the known expressions of the mean tunnelling time. However, some noticeable generalizations of (and deviations from) the Hartman effect are, as well, briefly investigated. Moreover, the analogy between particle and photon tunnelling is suitably exploited; on the basis of such an analogy, an explanation of some recent interesting microwave and optical experimental results on tunnelling times is proposed. Attention is devoted, at last, to some aspects of the causality problem for particle and photon tunnelling

The anisotropic tunneling behavior of spin transport in graphene-based magnetic tunneling junction

Science.gov (United States)

Pan, Mengchun; Li, Peisen; Qiu, Weicheng; Zhao, Jianqiang; Peng, Junping; Hu, Jiafei; Hu, Jinghua; Tian, Wugang; Hu, Yueguo; Chen, Dixiang; Wu, Xuezhong; Xu, Zhongjie; Yuan, Xuefeng

2018-05-01

Due to the theoretical prediction of large tunneling magnetoresistance (TMR), graphene-based magnetic tunneling junction (MTJ) has become an important branch of high-performance spintronics device. In this paper, the non-collinear spin filtering and transport properties of MTJ with the Ni/tri-layer graphene/Ni structure were studied in detail by utilizing the non-equilibrium Green's formalism combined with spin polarized density functional theory. The band structure of Ni-C bonding interface shows that Ni-C atomic hybridization facilitates the electronic structure consistency of graphene and nickel, which results in a perfect spin filtering effect for tri-layer graphene-based MTJ. Furthermore, our theoretical results show that the value of tunneling resistance changes with the relative magnetization angle of two ferromagnetic layers, displaying the anisotropic tunneling behavior of graphene-based MTJ. This originates from the resonant conduction states which are strongly adjusted by the relative magnetization angles. In addition, the perfect spin filtering effect is demonstrated by fitting the anisotropic conductance with the Julliere's model. Our work may serve as guidance for researches and applications of graphene-based spintronics device.

Improved multidimensional semiclassical tunneling theory.

Science.gov (United States)

Wagner, Albert F

2013-12-12

We show that the analytic multidimensional semiclassical tunneling formula of Miller et al. [Miller, W. H.; Hernandez, R.; Handy, N. C.; Jayatilaka, D.; Willets, A. Chem. Phys. Lett. 1990, 172, 62] is qualitatively incorrect for deep tunneling at energies well below the top of the barrier. The origin of this deficiency is that the formula uses an effective barrier weakly related to the true energetics but correctly adjusted to reproduce the harmonic description and anharmonic corrections of the reaction path at the saddle point as determined by second order vibrational perturbation theory. We present an analytic improved semiclassical formula that correctly includes energetic information and allows a qualitatively correct representation of deep tunneling. This is done by constructing a three segment composite Eckart potential that is continuous everywhere in both value and derivative. This composite potential has an analytic barrier penetration integral from which the semiclassical action can be derived and then used to define the semiclassical tunneling probability. The middle segment of the composite potential by itself is superior to the original formula of Miller et al. because it incorporates the asymmetry of the reaction barrier produced by the known reaction exoergicity. Comparison of the semiclassical and exact quantum tunneling probability for the pure Eckart potential suggests a simple threshold multiplicative factor to the improved formula to account for quantum effects very near threshold not represented by semiclassical theory. The deep tunneling limitations of the original formula are echoed in semiclassical high-energy descriptions of bound vibrational states perpendicular to the reaction path at the saddle point. However, typically ab initio energetic information is not available to correct it. The Supporting Information contains a Fortran code, test input, and test output that implements the improved semiclassical tunneling formula.

Superconducting tunnel-junction refrigerator

International Nuclear Information System (INIS)

Melton, R.G.; Paterson, J.L.; Kaplan, S.B.

1980-01-01

The dc current through an S 1 -S 2 tunnel junction, with Δ 2 greater than Δ 1 , when biased with eV 1 +Δ 2 , will lower the energy in S 1 . This energy reduction will be shared by the phonons and electrons. This device is shown to be analogous to a thermoelectric refrigerator with an effective Peltier coefficient π* approx. Δ 1 /e. Tunneling calculations yield the cooling power P/sub c/, the electrical power P/sub e/ supplied by the bias supply, and the cooling efficiency eta=P/sub c//P/sub e/. The maximum cooling power is obtained for eV= +- (Δ 2 -Δ 1 ) and t 1 =T 1 /T/sub c/1 approx. 0.9. Estimates are made of the temperature difference T 2 -T 1 achievable in Al-Pb and Sn-Pb junctions with an Al 2 O 3 tunneling barrier. The performance of this device is shown to yield a maximum cooling efficiency eta approx. = Δ 1 /(Δ 2 -Δ 1 ) which can be compared with that available in an ideal Carnot refrigerator of eta=T 1 /(T 2 -T 1 ). The development of a useful tunnel-junction refrigerator requires a tunneling barrier with an effective thermal conductance per unit area several orders of magnitude less than that provided by the A1 2 O 3 barrier in the Al-Pb and Sn-Pb systems

TunnelVision: LHC Tunnel Photogrammetry System for Structural Monitoring

CERN Document Server

Fallas, William

2014-01-01

In this document an algorithm to detect deformations in the LHC Tunnel of CERN is presented. It is based on two images, one represents the ideal state of the tunnel and the other one the actual state. To find the differences between both, the algorithm is divided in three steps. First, an image enhancement is applied to make easier the detection. Second, two different approaches to reduce noise are applied to one or both images. And third, it is defined a group of characteristics about the type of deformation desired to detect. Finally, the conclusions show the effectiveness of the algorithm in the experimental results.

Electric and VLF-MT survey of Tegatayama tunnel; Tegatayama tunnel no denki tansa oyobi VLF tansa

Energy Technology Data Exchange (ETDEWEB)

Nishitani, T [Akita University, Akita (Japan). Mining College

1997-05-27

To survey the structure at the depth between 20 and 30 m, field tests were conducted by means of vertical electric and VFL-MT (magnetotelluric) survey. Tegatayama tunnel has a total length of 276 m, width of 7.5 m, and height of 4.7 m, and the depth from the surface is about 28 m near the top of mountain. Near the tunnel, the thickness of surface soil is about 60 cm, which consists of clay soil including soft mudstone gravel. It was found that terrace deposit is distributed up to the depth of 8 m, and that mudstone is distributed below the depth of 8 m. Weighted four-electrode method was adopted for the vertical electrical survey. Measurements were conducted at the immediately above the tunnel, 10 m apart from the center of tunnel in the right and left, and 20 m apart from the center in the east. For the VLF-MT method, component of frequency 22.2 kHz was used. As a result of the tests, it was difficult to illustrate the existence of tunnel from the vertical electrical survey only at one point. Feature of the tunnel could be well illustrated by means of the VLF-MT method. 3 refs., 9 figs.

Characterization of the influence of building a road on the stability of the tunnel lining in a Banska Bystrica railway tunnel

Directory of Open Access Journals (Sweden)

Vavrek Pavol

2001-06-01

Full Text Available This paper deals with solving the problem of tunnel lining stability in a railway tunnel. The road cut was made into the overburden of the tunnel. I investigated the effect of the road cut on the stability of tunnel lining. The FLAC3D mathematical modelling technique was used for this purpose. The solution consist of: - - - - - - - - - - - -modelling the initial situation before building the intervention,Determing the internal characteristics of the tunnel lining in its original state,modelling the situation after making the road cut,Determing the internal characteristics of the tunnel lining after the building intervention,Comparison of the internal characteristics of the tunnel lining before and after the building intervention.In the model, I used these general geotechnical properties of the rock environment and the tunnel lining:Material Youngus modulus [MPa] Poissons RatioClay 8 0,42Weakly wheathered calcite 3 000 0,25Hard wheathered calcite 600 0,30Fill 300 0,25Lining 20 000 0,20The arbitration of the tunnel lining stability was executed on the basis of the Mohr – Coulomb limit of the state. Building the road cut does not lead to loss of stability in the tunnel a at Station 1.225 00 or at Station 1.300 00.

Paul Hill d/b/a Alternative Energy Windows and Siding

Science.gov (United States)

Paul Hill d/b/a Alternative Energy Windows and Siding (the Company) is located in Concord, New Hampshire. The settlement involves renovation activities conducted at property constructed prior to 1978, located in Concord, New Hampshire.

Electron tunneling in proteins program.

Science.gov (United States)

Hagras, Muhammad A; Stuchebrukhov, Alexei A

2016-06-05

We developed a unique integrated software package (called Electron Tunneling in Proteins Program or ETP) which provides an environment with different capabilities such as tunneling current calculation, semi-empirical quantum mechanical calculation, and molecular modeling simulation for calculation and analysis of electron transfer reactions in proteins. ETP program is developed as a cross-platform client-server program in which all the different calculations are conducted at the server side while only the client terminal displays the resulting calculation outputs in the different supported representations. ETP program is integrated with a set of well-known computational software packages including Gaussian, BALLVIEW, Dowser, pKip, and APBS. In addition, ETP program supports various visualization methods for the tunneling calculation results that assist in a more comprehensive understanding of the tunneling process. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Berkeley Nuclear Laboratories Reactor Physics Mk. III Experimental Programme. Description of facility and programme for 1971

Energy Technology Data Exchange (ETDEWEB)

Nunn, R M; Waterson, R H; Young, J D

1971-01-15

Reactor physics experiments have been carried out at Berkeley Nuclear Laboratories during the past few years in support of the Civil Advanced Gas-Cooled Reactors (Mk. II) the Generating Board is building. These experiments are part of an overall programme whose objective is to assess the accuracy of the calculational methods used in the design and operation of these reactors. This report provides a description of the facility for the Mk. III experimental programme and the planned programme for 1971.

Tunneling Anomalous and Spin Hall Effects.

Science.gov (United States)

Matos-Abiague, A; Fabian, J

2015-07-31

We predict, theoretically, the existence of the anomalous Hall effect when a tunneling current flows through a tunnel junction in which only one of the electrodes is magnetic. The interfacial spin-orbit coupling present in the barrier region induces a spin-dependent momentum filtering in the directions perpendicular to the tunneling current, resulting in a skew tunneling even in the absence of impurities. This produces an anomalous Hall conductance and spin Hall currents in the nonmagnetic electrode when a bias voltage is applied across the tunneling heterojunction. If the barrier is composed of a noncentrosymmetric material, the anomalous Hall conductance and spin Hall currents become anisotropic with respect to both the magnetization and crystallographic directions, allowing us to separate this interfacial phenomenon from the bulk anomalous and spin Hall contributions. The proposed effect should be useful for proving and quantifying the interfacial spin-orbit fields in metallic and metal-semiconductor systems.

Use of a krypton isotope for rapid ion changeover at the Lawrence Berkeley Laboratory 88-inch cyclotron

Science.gov (United States)

Soli, George A.; Nichols, Donald K.

1989-01-01

An isotope of krypton, Kr86, has been combined with a mix of Ar, Ne, and N ions at the electron cyclotron resonance (ECR) source, at the Lawrence Berkeley Laboratory cyclotron, to provide rapid ion changeover in Single Event Phenomena (SEP) testing. The new technique has been proved out successfully by a recent Jet Propulsion Laboratory (JPL) test in which it was found that there was no measurable contamination from other isotopes.

Relativistic tunneling through two successive barriers

International Nuclear Information System (INIS)

Lunardi, Jose T.; Manzoni, Luiz A.

2007-01-01

We study the relativistic quantum mechanical problem of a Dirac particle tunneling through two successive electrostatic barriers. Our aim is to study the emergence of the so-called generalized Hartman effect, an effect observed in the context of nonrelativistic tunneling as well as in its counterparts and which is often associated with the possibility of superluminal velocities in the tunneling process. We discuss the behavior of both the phase (or group) tunneling time and the dwell time, and show that in the limit of opaque barriers the relativistic theory also allows the emergence of the generalized Hartman effect. We compare our results with the nonrelativistic ones and discuss their interpretation

Thermodynamics of phonon-modulated tunneling centers

International Nuclear Information System (INIS)

Junker, W.; Wagner, M.

1989-01-01

In recent years tunneling centers have frequently been used to explain the unusual thermodynamic properties of disordered materials; in these approaches, however, the effect of the tunneling-phonon interaction is neglected. The present study considers the archetype model of phono-assisted tunneling, which is well known from other areas of tunneling physics (quantum diffusion, etc.). It is shown that the full thermodynamic information can be rigorously extracted from a single Green function. An extended factorization procedure beyond Hartree-Fock is introduced, which is checked by sum rules as well as by exact Goldberger-Adams expansions. The phonon-modulated internal energy and specific heat are calculated for different power-law coupling setups

Characterization of magnetic tunnel junction test pads

DEFF Research Database (Denmark)

Østerberg, Frederik Westergaard; Kjær, Daniel; Nielsen, Peter Folmer

2015-01-01

We show experimentally as well as theoretically that patterned magnetic tunnel junctions can be characterized using the current-in-plane tunneling (CIPT) method, and the key parameters, the resistance-area product (RA) and the tunnel magnetoresistance (TMR), can be determined. The CIPT method...

Food security and ecological footprint of chittagong hill tracts in bangladesh

International Nuclear Information System (INIS)

Bala, B.K.; Hossain, M.A.

2014-01-01

This paper presents food security and ecological footprint of the Chittagong Hill Tracts (CHT) in Bangladesh. To estimate food security and ecological footprint, primary and secondary data were collected and a multistage sampling was designed for selecting the farm households from the three districts of the Hill Tracts of Chittagong. A quantitative method for computation of food security was used. To estimate the environmental sustainability sustainability as upazila (sub-district) levels, a method of computation of ecological footprint developed by Wackernagel was used. Multiple logistic regression models were fitted to data on food security of the farmers in CHT to identify the factors affecting food security at household levels in CHT. Overall status of food security at upazila levels was found to be good for all the upazilas except Rangamati sadar and the best was found Alikadam. Environmental status in the Hill Tracts of Chittagong was poor for all the upazilas. Household food security was found to be significantly (p<0.05) affected by farm size, education, professions, crops cultivated (jhum and tobacco), distance from market and transition from jhum to horticulture. This study supports transition from jhum to horticulture crops for increased food security and banning tobacco cultivation to avoid deforestation in CHT. (author)

USGS Hill Shade Base Map Service from The National Map

Data.gov (United States)

U.S. Geological Survey, Department of the Interior — USGS Hill Shade (or Shaded Relief) is a tile cache base map created from the National Elevation Dataset (NED), a seamless dataset of best available raster elevation...

NPP Grassland: Beacon Hill, U.K., 1972-1993, R1

Data.gov (United States)

National Aeronautics and Space Administration — This data set contains two ASCII text files, one providing productivity measurements for a chalk grassland on Beacon Hill, West Sussex, U.K. (50.92 N, -0.85 W) and...

Franck-Condon fingerprinting of vibration-tunneling spectra.

Science.gov (United States)

Berrios, Eduardo; Sundaradevan, Praveen; Gruebele, Martin

2013-08-15

We introduce Franck-Condon fingerprinting as a method for assigning complex vibration-tunneling spectra. The B̃ state of thiophosgene (SCCl2) serves as our prototype. Despite several attempts, assignment of its excitation spectrum has proved difficult because of near-degenerate vibrational frequencies, Fermi resonance between the C-Cl stretching mode and the Cl-C-Cl bending mode, and large tunneling splittings due to the out-of-plane umbrella mode. Hence, the spectrum has never been fitted to an effective Hamiltonian. Our assignment approach replaces precise frequency information with intensity information, eliminating the need for double resonance spectroscopy or combination differences, neither of which have yielded a full assignment thus far. The dispersed fluorescence spectrum of each unknown vibration-tunneling state images its character onto known vibrational progressions in the ground state. By using this Franck-Condon fingerprint, we were able to determine the predominant character of several vibration-tunneling states and assign them; in other cases, the fingerprinting revealed that the states are strongly mixed and cannot be characterized with a simple normal mode assignment. The assigned transitions from vibration-tunneling wave functions that were not too strongly mixed could be fitted within measurement uncertainty by an effective vibration-tunneling Hamiltonian. A fit of all observed vibration-tunneling states will require a full resonance-tunneling Hamiltonian.

Ethnoveterinary medicine of the Shervaroy Hills of Eastern Ghats, India as alternative medicine for animals.

Science.gov (United States)

Usha, Swaminathan; Rajasekaran, Chandrasekaran; Siva, Ramamoorthy

2016-01-01

The Eastern Ghats of India is well known for its wealth of natural vegetation and Shervaroy is a major hill range of the Eastern Ghats of Tamil Nadu. Ethnomedicinal studies in the Eastern Ghats of Tamil Nadu or the Shervaroy Hills have been carried out by various researchers. However, there is not much information available on ethnoveterinary medicine in the Eastern Ghats of India. The aim of this study was to examine the potential use of folk plants as alternative medicine for cattle to cure various diseases in the Shervaroy Hills of the Eastern Ghats. Based on interactions with traditional medicine practitioners, it has been observed that a total of 21 medicinal plants belonging to 16 families are used to cure various diseases such as mastitis, enteritis, arthritis, stomatitis, salivation from the mouth, wounding, and conjunctivitis in animals. It has been observed that the traditional knowledge of ethnoveterinary medicine is now confined only among the surviving older people and a few practitioners in the tribal communities of the Shervaroy Hills. Unfortunately, no serious attempts have been made to document and preserve this immense treasure of traditional knowledge.

Hawking temperature from tunnelling formalism

OpenAIRE

Mitra, P.

2007-01-01

It has recently been suggested that the attempt to understand Hawking radiation as tunnelling across black hole horizons produces a Hawking temperature double the standard value. It is explained here how one can obtain the standard value in the same tunnelling approach.

Homoepitaxial graphene tunnel barriers for spin transport

Directory of Open Access Journals (Sweden)

Adam L. Friedman

2016-05-01

Full Text Available Tunnel barriers are key elements for both charge-and spin-based electronics, offering devices with reduced power consumption and new paradigms for information processing. Such devices require mating dissimilar materials, raising issues of heteroepitaxy, interface stability, and electronic states that severely complicate fabrication and compromise performance. Graphene is the perfect tunnel barrier. It is an insulator out-of-plane, possesses a defect-free, linear habit, and is impervious to interdiffusion. Nonetheless, true tunneling between two stacked graphene layers is not possible in environmental conditions usable for electronics applications. However, two stacked graphene layers can be decoupled using chemical functionalization. Here, we demonstrate that hydrogenation or fluorination of graphene can be used to create a tunnel barrier. We demonstrate successful tunneling by measuring non-linear IV curves and a weakly temperature dependent zero-bias resistance. We demonstrate lateral transport of spin currents in non-local spin-valve structures, and determine spin lifetimes with the non-local Hanle effect. We compare the results for hydrogenated and fluorinated tunnel and we discuss the possibility that ferromagnetic moments in the hydrogenated graphene tunnel barrier affect the spin transport of our devices.

Homoepitaxial graphene tunnel barriers for spin transport

Science.gov (United States)

Friedman, Adam L.; van't Erve, Olaf M. J.; Robinson, Jeremy T.; Whitener, Keith E.; Jonker, Berend T.

2016-05-01

Tunnel barriers are key elements for both charge-and spin-based electronics, offering devices with reduced power consumption and new paradigms for information processing. Such devices require mating dissimilar materials, raising issues of heteroepitaxy, interface stability, and electronic states that severely complicate fabrication and compromise performance. Graphene is the perfect tunnel barrier. It is an insulator out-of-plane, possesses a defect-free, linear habit, and is impervious to interdiffusion. Nonetheless, true tunneling between two stacked graphene layers is not possible in environmental conditions usable for electronics applications. However, two stacked graphene layers can be decoupled using chemical functionalization. Here, we demonstrate that hydrogenation or fluorination of graphene can be used to create a tunnel barrier. We demonstrate successful tunneling by measuring non-linear IV curves and a weakly temperature dependent zero-bias resistance. We demonstrate lateral transport of spin currents in non-local spin-valve structures, and determine spin lifetimes with the non-local Hanle effect. We compare the results for hydrogenated and fluorinated tunnel and we discuss the possibility that ferromagnetic moments in the hydrogenated graphene tunnel barrier affect the spin transport of our devices.

Does flexible tunnel drilling affect the femoral tunnel angle measurement after anterior cruciate ligament reconstruction?

NARCIS (Netherlands)

Muller, Bart; Hofbauer, Marcus; Atte, Akere; van Dijk, C. Niek; Fu, Freddie H.

2015-01-01

To quantify the mean difference in femoral tunnel angle (FTA) as measured on knee radiographs between rigid and flexible tunnel drilling after anatomic anterior cruciate ligament (ACL) reconstruction. Fifty consecutive patients that underwent primary anatomic ACL reconstruction with a single femoral

A review on all-perovskite multiferroic tunnel junctions

Directory of Open Access Journals (Sweden)

Yuewei Yin

2017-12-01

Full Text Available Although the basic concept was proposed only about 10 years ago, multiferroic tunnel junctions (MFTJs with a ferroelectric barrier sandwiched between two ferromagnetic electrodes have already drawn considerable interests, driven mainly by its potential applications in multi-level memories and electric field controlled spintronics. The purpose of this article is to review the recent progress of all-perovskite MFTJs. Starting from the key functional properties of the tunneling magnetoresistance, tunneling electroresistance, and tunneling electromagnetoresistance effects, we discuss the main origins of the tunneling electroresistance effect, recent progress in achieving multilevel resistance states in a single device, and the electrical control of spin polarization and transport through the ferroelectric polarization reversal of the tunneling barrier.

Unified time analysis of photon and particle tunnelling

International Nuclear Information System (INIS)

Olkhovsky, Vladislav S.; Recami, Erasmo; Jakiel, Jacek

2001-07-01

A unified approach to the time analysis of tunnelling of nonrelativistic particles is presented, in which Time is regarded as a quantum-mechanical observable, canonically conjugated to Energy. The validity of the Hartman effect (independence of the Tunnelling Time of the opaque barrier width, with superluminal group velocities as a consequence) is verified for all the known expressions of the mean tunnelling time. Moreover, the analogy between particle and photon tunnelling is suitably exploited. On the basic of such an analogy, an explanation of some recent microwave and optics experimental results on tunnelling time is proposed. Attention is devoted to some aspects of the causality problem for particle and photon tunnelling. (author)

77 FR 47625 - Laurel Hill Wind Energy, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

Science.gov (United States)

2012-08-09

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER12-2313-000] Laurel Hill Wind Energy, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request For... Laurel Hill Wind Energy, LLC's application for market-based rate authority, with an accompanying rate...

Time evolution of tunneling in a thermal medium: Environment-driven excited tunneling

International Nuclear Information System (INIS)

Matsumoto, Sh.; Yoshimura, M.

2004-01-01

Time evolution of tunneling phenomena proceeding in a thermal medium is studied using a standard model of environmental interaction. A semiclassical probability formula for the particle motion in a metastable state of a one-dimensional system put in a thermal medium is combined with the formula of the quantum penetration factor through a potential barrier to derive the tunneling rate in the medium. The effect of environment, its influence on time evolution in particular, is clarified in our real-time formalism. A nonlinear resonance effect is shown to enhance the tunneling rate at finite times of order 2/η, with η the friction coefficient unless η is too small. In the linear approximation this effect has relevance to the parametric resonance. This effect enhances the possibility of early termination of the cosmological phase transition much prior to the typical Hubble time

Amphibian diversity in Shimba Hills National Reserve, Kenya: A ...

African Journals Online (AJOL)

We present the first annotated amphibian checklist of Shimba Hills National Reserve (SHNR). The list comprises of 30 currently known amphibians (28 anurans and two caecilians), which includes 11 families and 15 genera. In addition, individual records per species, distribution in the reserve and brief remarks about the ...

Quantum Electron Tunneling in Respiratory Complex I1

Science.gov (United States)

Hayashi, Tomoyuki; Stuchebrukhov, Alexei A.

2014-01-01

We have simulated the atomistic details of electronic wiring of all Fe/S clusters in complex I, a key enzyme in the respiratory electron transport chain. The tunneling current theory of many-electron systems is applied to the broken-symmetry (BS) states of the protein at the ZINDO level. One-electron tunneling approximation is found to hold in electron tunneling between the anti-ferromagnetic binuclear and tetranuclear Fe/S clusters with moderate induced polarization of the core electrons. Calculated tunneling energy is about 3 eV higher than Fermi level in the band gap of the protein, which supports that the mechanism of electron transfer is quantum mechanical tunneling, as in the rest of electron transport chain. Resulting electron tunneling pathways consist of up to three key contributing protein residues between neighboring Fe/S clusters. A distinct signature of the wave properties of electrons is observed as quantum interferences when multiple tunneling pathways exist. In N6a-N6b, electron tunnels along different pathways depending on the involved BS states, suggesting possible fluctuations of the tunneling pathways driven by the local protein environment. The calculated distance dependence of the electron transfer rates with internal water molecules included are in good agreement with a reported phenomenological relation. PMID:21495666

Development of the safety control framework for shield tunneling in close proximity to the operational subway tunnels: case studies in mainland China.

Science.gov (United States)

Li, Xinggao; Yuan, Dajun

2016-01-01

China's largest cities like Beijing and Shanghai have seen a sharp increase in subway network development as a result of the rapid urbanization in the last decade. The cities are still expanding their subway networks now, and many shield tunnels are being or will be constructed in close proximity to the existing operational subway tunnels. The execution plans for the new nearby shield tunnel construction calls for the development of a safety control framework-a set of control standards and best practices to help organizations manage the risks involved. Typical case studies and relevant key technical parameters are presented with a view to presenting the resulting safety control framework. The framework, created through collaboration among the relevant parties, addresses and manages the risks in a systematic way based on actual conditions of each tunnel crossing construction. The framework consists of six parts: (1) inspecting the operational subway tunnels; (2) deciding allowed movements of the existing tunnels and tracks; (3) simulating effects of the shield tunneling on the existing tunnels; (4) doing preparation work; (5) monitoring design and information management; and (6) measures and activation mechanism of the countermeasures. The six components are explained and demonstrated in detail. In the end, discussions made involve construction and post-construction settlement of the operational tunnel, application of the remedial grouting to rectify excessive settlements of the operational tunnel, and use of the innovative tool of the optical fiber measurement for tunnel movement monitoring. It is concluded that the construction movement of the tunnel can be controlled within 15 mm when the shield machine is <7 m in excavation diameter. The post-construction settlement of the tunnel buried in the very soft ground is much greater than its construction settlement, and last several years until reaching a final stable state. Two cases are outlined to demonstrate the

Stability of the Zagreb realization of the Carnegie-Mellon-Berkeley coupled-channels unitary model

International Nuclear Information System (INIS)

Osmanovic, H.; Hadzimehmedovic, M.; Stahov, J.; Ceci, S.; Svarc, A.

2011-01-01

In Hadzimehmedovicet al.[Phys. Rev. C 84, 035204 (2011)] we have used the Zagreb realization of Carnegie-Melon-Berkeley coupled-channel, unitary model as a tool for extracting pole positions from the world collection of partial-wave data, with the aim of eliminating model dependence in pole-search procedures. In order that the method is sensible, we in this paper discuss the stability of the method with respect to the strong variation of different model ingredients. We show that the Zagreb CMB procedure is very stable with strong variation of the model assumptions and that it can reliably predict the pole positions of the fitted partial-wave amplitudes.

Time-resolved scanning tunnelling microscopy

NARCIS (Netherlands)

van Houselt, Arie; Zandvliet, Henricus J.W.

2010-01-01

Scanning tunneling microscopy has revolutionized our ability to image, study, and manipulate solid surfaces on the size scale of atoms. One important limitation of the scanning tunneling microscope (STM) is, however, its poor time resolution. Recording a standard image with a STM typically takes

Apparent tunneling in chemical reactions

DEFF Research Database (Denmark)

Henriksen, Niels Engholm; Hansen, Flemming Yssing; Billing, G. D.

2000-01-01

A necessary condition for tunneling in a chemical reaction is that the probability of crossing a barrier is non-zero, when the energy of the reactants is below the potential energy of the barrier. Due to the non-classical nature (i.e, momentum uncertainty) of vibrational states this is, however......, not a sufficient condition in order to establish genuine tunneling as a result of quantum dynamics. This proposition is illustrated for a two-dimensional model potential describing dissociative sticking of N-2 on Ru(s). It is suggested that the remarkable heavy atom tunneling, found in this system, is related...

Quantum dot resonant tunneling diode single photon detector with aluminum oxide aperture defined tunneling area

DEFF Research Database (Denmark)

Li, H.W.; Kardynal, Beata; Ellis, D.J.P.

2008-01-01

Quantum dot resonant tunneling diode single photon detector with independently defined absorption and sensing areas is demonstrated. The device, in which the tunneling is constricted to an aperture in an insulating layer in the emitter, shows electrical characteristics typical of high quality res...

Unidirectional magnetoelectric-field multiresonant tunneling

International Nuclear Information System (INIS)

Kamenetskii, E O; Hollander, E; Joffe, R; Shavit, R

2015-01-01

Unidirectional multi-resonant tunneling of the magnetoelectric (ME) field excitations through a subwavelength (regarding the scales of regular electromagnetic radiation) vacuum or isotropic-dielectric regions has been observed in two-port microwave structures having a quasi-2D ferrite disk with magnetic dipolar mode (MDM) oscillations. The excitations manifest themselves as Fano-resonance peaks in the scattering-matrix parameters at the stationary states of the MDM spectrum. The ME near-field excitations are quasimagnetostatic fields ∇-vector × H-vector =0 with non-zero helicity parameter: F=(1/(16π))Im{ E-vector ⋅( ∇-vector × E-vector ) ∗ }. Topological phase properties of ME fields are determined by edge chiral currents of MDM oscillations. We show that while for a given direction of a bias magnetic field (in other words, for a given direction of time), the ME field excitations are considered as ‘forward’ tunneling processes, in the opposite direction of a bias magnetic field (the opposite direction of time), there are ‘backward’ tunneling processes. Unidirectional ME field resonant tunneling is observed due to the distinguishable topology of the ‘forward’ and ‘backward’ ME field excitations. We establish a close connection between the Fano-resonance unidirectional tunneling and the topology of the ME fields in different microwave structures. (paper)

MR imaging of the carpal tunnel syndrome

International Nuclear Information System (INIS)

Elias, D.; Lind, J.; Blair, S.; Light, T.; Wisniewski, R.; Moncado, R.

1987-01-01

MR is an ideal noninvasive means to image the structures forming the carpal tunnel in both normal and pathologic conditions. The carpal tunnel syndrome is a frequently encountered entity caused by compression of the median nerve as it passes through the carpal tunnel. This may result from a variety of conditions including edema from acute chronic trauma, rheumatoid tenosynovitis, degenerative joint disease or soft-tissue masses. This exhibit demonstrates the optimal MR imaging techniques to display the structures of the carpal tunnel. The normal anatomy is reviewed and variations in normal anatomy that may predispose to disease are included. Examples of the morphologic changes demonstrated in 20 patients diagnosed with carpal tunnel syndrome are displayed. The exhibit also reviews the findings in 20 postoperative cases

Concept development for HLW disposal research tunnel

International Nuclear Information System (INIS)

Queon, S. K.; Kim, K. S.; Park, J. H.; Jeo, W. J.; Han, P. S.

2003-01-01

In order to dispose high-level radioactive waste in a geological formation, it is necessary to assess the safety of a disposal concept by excavating a research tunnel in the same geological formation as the host rock mass. The design concept of a research tunnel depends on the actual disposal concept, repository geometry, experiments to be carried at the tunnel, and geological conditions. In this study, analysis of the characteristics of the disposal research tunnel, which is planned to be constructed at KAERI site, calculation of the influence of basting impact on neighbor facilities, and computer simuation for mechanical stability analysis using a three-dimensional code, FLAC3D, had been carried out to develop the design concept of the research tunnel

Crystal chemistry of pyrochlore from the Mesozoic Panda Hill carbonatite deposit, western Tanzania

Science.gov (United States)

Boniface, Nelson

2017-02-01

The Mesozoic Panda Hill carbonatite deposit in western Tanzania hosts pyrochlore, an ore and source of niobium. This study was conducted to establish the contents of radioactive elements (uranium and thorium) in pyrochlore along with the concentration of niobium in the ore. The pyrochlore is mainly hosted in sövite and is structurally controlled by NW-SE (SW dipping) or NE-SW (NW dipping) magmatic flow bands with dip angles of between 60° and 90°. Higher concentrations of pyrochlore are associated with magnetite, apatite and/or phlogopite rich flow bands. Electron microprobe analyses on single crystals of pyrochlore yield very low UO2 concentrations that range between 0 and 0.09 wt% (equivalent to 0 atoms per formula unit: a.p.f.u.) and ThO2 between 0.55 and 1.05 wt% (equivalent to 0.1 a.p.f.u.). The analyses reveal high concentrations of Nb2O5 (ranging between 57.13 and 65.50 wt%, equivalent to a.p.f.u. ranging between 1.33 and 1.43) and therefore the Panda Hill Nb-oxide is classified as pyrochlore sensu stricto. These data point to a non radioactive pyrochlore and a deposit rich in Nb at Panda Hill. The Panda Hill pyrochlore has low concentrations of REEs as displayed by La2O3 that range between 0.10 and 0.49 wt% (equivalent to a.p.f.u. ranging between 0 and 0.01) and Ce2O3 ranging between 0.86 and 1.80 wt% (equivalent to a.p.f.u. ranging between 0.02 and 0.03), Pr2O3 concentrations range between 0 and 0.23 wt% (equivalent to 0 a.p.f.u.), and Y2O3 is 0 wt% (equivalent to 0 a.p.f.u.). The abundance of the REEs in pyroclore at the Panda Hill Carbonatite deposit is of no economic significance.

Seismic Response of Tunnel Lining for Shallow-Bias Tunnel with a Small Clear Distance under Wenchuan Earthquake

Directory of Open Access Journals (Sweden)

Yang Hui

2018-01-01

Full Text Available In order to study the internal force characteristics of shallow-bias tunnel with a small clear distance in earthquake, a large-scale shaking table slope model test was designed, and the geometric scale was 1 : 10. In the model test, the Wenchuan (WC seismic wave was used as the excitation wave. Then, the three-dimensional numerical model was established by using MIDAS-NX, and the reliability of the numerical model was verified by comparing the acceleration of the test results. The axial force, bending moment, and shear force of the tunnel cross section and longitudinal direction were calculated by the numerical model under different excitation directions included the horizontal direction (X, the vertical direction (Z, and the horizontal and vertical direction (XZ. The results show the following. (1 The internal force of right arch foot of left hole and the left arch foot of right hole is larger than other part of the tunnels because the distance between the two tunnels is smaller and they interact with each other. (2 The loading direction of single direction loading method is different and the variation trend of tunnel force are different, so the loading direction of seismic wave has a significant influence on the seismic force response of the tunnel. (3 All of the internal force values of tunnel lining under the seismic wave action in bidirection are larger than those in single direction. The value is not a simple superposition of two directions and has some coupling effect. The influence of the vertical seismic wave cannot be ignored in dynamic response research. These results improve the understanding of the rock slope with small spacing tunnel under seismic action.

Petrographic and geochemical data for Cenozoic volcanic rocks of the Bodie Hills, California and Nevada

Science.gov (United States)

du Bray, Edward A.; John, David A.; Box, Stephen E.; Vikre, Peter G.; Fleck, Robert J.; Cousens, Brian L.

2013-04-23

Petrographic and geochemical data for Cenozoic volcanic rocks of the Bodie Hills, California and Nevada // // This report presents petrographic and geochemical data for samples collected during investigations of Tertiary volcanism in the Bodie Hills of California and Nevada. Igneous rocks in the area are principally 15–6 Ma subduction-related volcanic rocks of the Bodie Hills volcanic field but also include 3.9–0.1 Ma rocks of the bimodal, post-subduction Aurora volcanic field. Limited petrographic results for local basement rocks, including Mesozoic granitoid rocks and their metamorphic host rocks, are also included in the compilation. The petrographic data include visual estimates of phenocryst abundances as well as other diagnostic petrographic criteria. The geochemical data include whole-rock major oxide and trace element data, as well as limited whole-rock isotopic data.

DNS Tunneling Detection Method Based on Multilabel Support Vector Machine

Directory of Open Access Journals (Sweden)

Ahmed Almusawi

2018-01-01

Full Text Available DNS tunneling is a method used by malicious users who intend to bypass the firewall to send or receive commands and data. This has a significant impact on revealing or releasing classified information. Several researchers have examined the use of machine learning in terms of detecting DNS tunneling. However, these studies have treated the problem of DNS tunneling as a binary classification where the class label is either legitimate or tunnel. In fact, there are different types of DNS tunneling such as FTP-DNS tunneling, HTTP-DNS tunneling, HTTPS-DNS tunneling, and POP3-DNS tunneling. Therefore, there is a vital demand to not only detect the DNS tunneling but rather classify such tunnel. This study aims to propose a multilabel support vector machine in order to detect and classify the DNS tunneling. The proposed method has been evaluated using a benchmark dataset that contains numerous DNS queries and is compared with a multilabel Bayesian classifier based on the number of corrected classified DNS tunneling instances. Experimental results demonstrate the efficacy of the proposed SVM classification method by obtaining an f-measure of 0.80.

Seepage into PEP tunnel

International Nuclear Information System (INIS)

Weidner, H.

1990-01-01

The current rate of seepage into the PEP tunnel in the vicinity of IR-10 is very low compared to previous years. Adequate means of handling this low flow are in place. It is not clear whether the reduction in the flow is temporary, perhaps due to three consecutive dry years, or permanent due to drainage of a perched water table. During PEP construction a large amount of effort was expended in attempts to seal the tunnel, with no immediate effect. The efforts to ''manage'' the water flow are deemed to be successful. By covering equipment to protect it from dripping water and channeling seepage into the drainage gutters, the seepage has been reduced to a tolerable nuisance. There is no sure, safe procedure for sealing a leaky shotcreted tunnel

Conservation assessment for the autumn willow in the Black Hills National Forest, South Dakota and Wyoming

Science.gov (United States)

J. Hope Hornbeck; Carolyn Hull Sieg; Deanna J. Reyher

2003-01-01

Autumn willow, Salix serissima (Bailey) Fern., is an obligate wetland shrub that occurs in fens and bogs in the northeastern United States and eastern Canada. Disjunct populations of autumn willow occur in the Black Hills of South Dakota. Only two populations occur on Black Hills National Forest lands: a large population at McIntosh Fen and a small...

78 FR 76100 - Black Hills National Forest Advisory Board

Science.gov (United States)

2013-12-16

...: The Black Hills National Forest Advisory Board (Board) will meet in Rapid City, South Dakota. The... Ranger District, 8221 South Highway 16, Rapid City, South Dakota. Written comments may be submitted as... the public. The agenda will include time for people to make oral statements of three minutes or less...

Tunneling Plasmonics in Bilayer Graphene.

Science.gov (United States)

Fei, Z; Iwinski, E G; Ni, G X; Zhang, L M; Bao, W; Rodin, A S; Lee, Y; Wagner, M; Liu, M K; Dai, S; Goldflam, M D; Thiemens, M; Keilmann, F; Lau, C N; Castro-Neto, A H; Fogler, M M; Basov, D N

2015-08-12

We report experimental signatures of plasmonic effects due to electron tunneling between adjacent graphene layers. At subnanometer separation, such layers can form either a strongly coupled bilayer graphene with a Bernal stacking or a weakly coupled double-layer graphene with a random stacking order. Effects due to interlayer tunneling dominate in the former case but are negligible in the latter. We found through infrared nanoimaging that bilayer graphene supports plasmons with a higher degree of confinement compared to single- and double-layer graphene, a direct consequence of interlayer tunneling. Moreover, we were able to shut off plasmons in bilayer graphene through gating within a wide voltage range. Theoretical modeling indicates that such a plasmon-off region is directly linked to a gapped insulating state of bilayer graphene, yet another implication of interlayer tunneling. Our work uncovers essential plasmonic properties in bilayer graphene and suggests a possibility to achieve novel plasmonic functionalities in graphene few-layers.

Tunneling with dissipation in open quantum systems