153,073 research outputs found
Method for removing oxygen impurities from cesium Patent
Heated tungsten filter for removing oxygen impurities from cesiu
Pressure, compressibility, and contact of the two-dimensional attractive Fermi gas
Using ab initio lattice methods, we calculate the finite temperature
thermodynamics of homogeneous two-dimensional spin-1/2 fermions with attractive
short-range interactions. We present results for the density, pressure,
compressibility, and quantum anomaly (i.e. Tan's contact) for a wide range of
temperatures and coupling strengths, focusing on the unpolarized case. Within
our statistical and systematic uncertainties, our prediction for the density
equation of state differs quantitatively from the prediction by Luttinger-Ward
theory in the strongly coupled region of parameter space, but otherwise agrees
well with it. We also compare our calculations with the second- and third-order
virial expansion, with which they are in excellent agreement in the
low-fugacity regime.Comment: 7 pages, 8 figures, including supplemental material
Operator Evolution via the Similarity Renormalization Group I: The Deuteron
Similarity Renormalization Group (SRG) flow equations can be used to
unitarily soften nuclear Hamiltonians by decoupling high-energy intermediate
state contributions to low-energy observables while maintaining the natural
hierarchy of many-body forces. Analogous flow equations can be used to
consistently evolve operators so that observables are unchanged if no
approximations are made. The question in practice is whether the advantages of
a softer Hamiltonian and less correlated wave functions might be offset by
complications in approximating and applying other operators. Here we examine
the properties of SRG-evolved operators, focusing in this paper on applications
to the deuteron but leading toward methods for few-body systems. We find the
advantageous features generally carry over to other operators with additional
simplifications in some cases from factorization of the unitary transformation
operator.Comment: 33 pages, 19 figures. Improved figures 17 and 18. Expanded comments
on OPE in tex
The national land use data program of the US Geological Survey
The Land Use Data and Analysis (LUDA) Program which provides a systematic and comprehensive collection and analysis of land use and land cover data on a nationwide basis is described. Maps are compiled at about 1:125,000 scale showing present land use/cover at Level II of a land use/cover classification system developed by the U.S. Geological Survey in conjunction with other Federal and state agencies and other users. For each of the land use/cover maps produced at 1:125,000 scale, overlays are also compiled showing Federal land ownership, river basins and subbasins, counties, and census county subdivisions. The program utilizes the advanced technology of the Special Mapping Center of the U.S. Geological Survey, high altitude NASA photographs, aerial photographs acquired for the USGS Topographic Division's mapping program, and LANDSAT data in complementary ways
Operator Evolution via the Similarity Renormalization Group I: The Deuteron
Similarity Renormalization Group (SRG) flow equations can be used to
unitarily soften nuclear Hamiltonians by decoupling high-energy intermediate
state contributions to low-energy observables while maintaining the natural
hierarchy of many-body forces. Analogous flow equations can be used to
consistently evolve operators so that observables are unchanged if no
approximations are made. The question in practice is whether the advantages of
a softer Hamiltonian and less correlated wave functions might be offset by
complications in approximating and applying other operators. Here we examine
the properties of SRG-evolved operators, focusing in this paper on applications
to the deuteron but leading toward methods for few-body systems. We find the
advantageous features generally carry over to other operators with additional
simplifications in some cases from factorization of the unitary transformation
operator.Comment: 33 pages, 19 figures. Improved figures 17 and 18. Expanded comments
on OPE in tex
It's all action, it's all learning: Action learning in SMEs
Purpose - The purpose of this paper is to argue that action learning (AL) may provide a means of successfully developing small to medium-sized enterprises (SMEs). Design/methodology/approach - The literature around SME learning suggests a number of processes are important for SME learning which similarity, it is argued, are encompassed in AL. AL may therefore offer a means of developing SME. This argument is then supported through the results of a longitudinal qualitative evaluation study conducted in the north-west of England, which involved the use of AL in 100 SMEs. Findings - The paper finds that the discursive and critical reflection aspects of the set environment appeared to be of great utility and importance to the SMEs. Sets also had an optimum level of which helped them find "common ground". Once common ground was established set members often continued to network and form alliances outside of the set environment. SME owner-managers could discuss both personal and business. Finally, AL offered the opportunity to take time out of the business and "disengage" with the operational allowing them to become more strategic. Practical implications - In this paper both the literature review and the results of the evaluation suggest AL may offer a means of engaging SMEs in training, which is relevant and useful to them. AL offers a way for policy makers and support agencies to get involved with SME management development while retaining context and naturalistic conditions. Originality/value - This paper attempts to move beyond other articles which assess SME response to government initiatives, through examining the literature around SME learning and constructing a rationale which proposes that AL encompasses many of the learning processes suggested in the literature as effective for SME development. © Emerald Group Publishing Limited
Regional Land Use Mapping: the Phoenix Pilot Project
The Phoenix Pilot Program has been designed to make effective use of past experience in making land use maps and collecting land use information. Conclusions reached from the project are: (1) Land use maps and accompanying statistical information of reasonable accuracy and quality can be compiled at a scale of 1:250,000 from orbital imagery. (2) Orbital imagery used in conjunction with other sources of information when available can significantly enhance the collection and analysis of land use information. (3) Orbital imagery combined with modern computer technology will help resolve the problem of obtaining land use data quickly and on a regular basis, which will greatly enhance the usefulness of such data in regional planning, land management, and other applied programs. (4) Agreement on a framework or scheme of land use classification for use with orbital imagery will be necessary for effective use of land use data
Investigation of temperature and concentration oscillations in the directional solidification of Pb-Sn-Te
Directional solidification of the pseudobinary compound semiconductor material Pb sub 1-x Sn sub x Te by the Bridgman crystal growth process will be studied. Natural convection in the molten sample will be visualized with a novel electrochemical cell technique that employs the solid electrolyte material yttria-stabilized zirconia. Mass transfer by both diffusion and convection will be measured by detecting the motion of oxygen tracer in the liquid. Additional applications for electrochemical cells in semiconductor crystal growth are suggested. Unsteady convection in the melt will also be detected by the appearance of temperature oscillations. The purpose of this study is to experimentally characterize the overstable conditions for a Pb sub 1-x Sn sub x Te melt in the vertical Bridgman crystal growth technique and use a linear analysis to predict the onset of convection for this system
Automatic transponder
A method and apparatus for the automatic, remote measurement of the internal delay time of a transponder at the time of operation is provided. A small portion of the transmitted signal of the transponder is converted to the receive signal frequency of the transponder and supplied to the input of the transponder. The elapsed time between the receive signal locally generated and the receive signal causing the transmission of the transmitted signal is measured, said time being representative of or equal to the internal delay time of the transponder at the time of operation
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