145 research outputs found
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Design and fabrication of the MFTF-B magnet system
The MFTF-B superconducting magnet system consists of 40 NbTi magnets and two Nb/sub 3/Sn magnets. General Dynamics (GD) designed all magnets except for the small trim coils. GD then fabricated 20 NbTi magnets, while LLNL fabricated 20 NbTi magnets and two Nb/sub 3/Sn magnets. The design phase was completed in February 1984 and included the competitive procurement of magnet structural fabrication, superconductor, G-10CR insulation, support struts and bearings, vapor-cooled leads, and thermal shields for all magnets. Fabrication of all magnets was completed in March 1985. At GD, dual assembly lines were necessary during fabrication in order to meet the aggressive LLNL schedule. The entire magnet system has been installed and aligned at LLNL, and Tech Demo tests will be performed during September-November 1985
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Confirmatory analysis and detail design of the magnet system for mirror fusion test facility (MFTF)
This summary covers the six individual reports delivered to the LLL MFTF program staff. They are: (1) literature survey (helium heat transfer), (2) thermodynamic analysis, (3) structural analysis, (4) manufacturing/producibility study, (5) instrumentation plan and (6) quality assurance report. (MOW
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Cooldown and warmup thermal analysis of the mirror fusion test facility (MFTF) superconducting magnet
General Dynamics Convair Division has performed a series of detailed cooldown and warmup thermal analyses to support the design of the Lawrence Livermore Laboratory (LLL), Mirror Fusion Test Facility (MFTF) magnet system. The analyses were conducted under LLL Contract 9815603. All analysis objectives were achieved, including definition of a cooldown and warmup operating schedule which can (1) effect complete cooldown and warmup within three to five days (an LLL requirement), (2) yield acceptable levels of thermally-induced stresses resulting from transverse and longitudinal structural temperature differentials, and (3) yield acceptable stress levels with or without flow imbalances in separate sections of the magnet. The analyses were executed through the National magnetic Fusion Energy Computer Center (NMFECC) at LLL
Changes in Adolescent Birth Rates within Appalachian Subregions and Non-Appalachian Counties in the United States, 2012–2018
Background: Adolescent births are associated with numerous challenges. While adolescent birth rates have declined across the U.S., disparities persist and little is known about the extent to which broader declines are seen within Appalachia.
Purpose: The purpose of this study was to examine the extent to which adolescent birth rates have declined across the subregions of Appalachia relative to non-Appalachia.
Methods: We conducted a retrospective study of adolescent birth rates between 2012 and 2018 using county-level vital records data. Differences were examined across the subregions of Appalachia and among non-Appalachian counties. Multiple regression models were used to examine changes in the rate of decline over time, adjusting for additional covariates of relevance.
Results: About 13.4% of all counties in the U.S. are within the Appalachian region. The rate of adolescent births decreased by 12.6 adolescent births per 1,000 females between 2012 and 2018 across the U.S. While all regions experienced declines in the rate of adolescent births, Central Appalachia had the largest reduction in adolescent births (18.5 per 1,000 females), which was also noted in the adjusted models when compared to the counties of non-Appalachia (b= –5.78, CI: –9.58, –1.97). Rates of adolescent birth were markedly higher in counties considered among the most socially and economically vulnerable.
Implications: This study demonstrates that the rates of adolescent births vary across the subregions of Appalachia but have declined proportional to rates in non-Appalachia. While adolescent birth rates remain higher in select subregions of Appalachia compared to non-Appalachia, the gap has narrowed considerably
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Design and fabrication of the superconducting-magnet system for the Mirror Fusion Test Facility (MFTF-B)
The superconducting magnet system for the Mirror Fusion Test Facility (MFTF-B) consists of 24 magnets; i.e. two pairs of C-shaped Yin-Yang coils, four C-shaped transition coils, four solenoidal axicell coils, and a 12-solenoid central cell. General Dynamics Convair Division has designed all the coils and is responsible for fabricating 20 coils. The two Yin-Yang pairs (four coils) are being fabricated by the Lawrence Livermore National Laboratory. Since MFTF-B is not a magnet development program, but rather a major physics experiment critical to the mirror fusion program, the basic philosophy has been to use proven materials and analytical techniques wherever possible. The transition and axicell coils are currently being analyzed and designed, while fabrication is under way on the solenoid magnets
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Design features of the solenoid magnets for the central cell of the MFTF-B
The 14 superconducting solenoid magnets which form the central cell of the MFTF-B are being designed and fabricated by General Dynamics for the Lawrence Livermore National Laboratory. Each solenoid coil has a mean diameter of five meters and contains 600 turns of a proven conductor type. Structural loading resulting from credible fault events, cooldown and warmup requirements, and manufacturing processes consistent with other MFTF-B magnets have been considered in the selection of 304 LN as the structural material for the magnet. The solenoid magnets are connected by 24 intercoil beams and 20 solid struts which resist the longitudinal seismic and electromagnetic attractive forces and by 24 hanger/side supports which react magnet dead weight and seismic loads. A modular arrangement of two solenoid coils within a vacuum vessel segment allow for sequential checkout and installation
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Design features of the A-cell and transition coils of MFTF-B
The MFTF-B transition coil and A-cell magnet designs use variations of the copper-stabilized NbTi conductor developed by LLNL for the MFTF Yin-Yang magnets. This conductor will be wound on the one inch thick (12.7 mm) stainless steel coil forms using a two-axis winding machine similar to the existing LLNL Yin-Yang winding machine. After winding, covers will be placed over the coil and welded to the coil form to form a helium-tight jacket around the conductor. These jacketed coils are then enclosed in thick structural cases that react the large Lorentz forces on the magnets. The space between the coil jacket and case will be filled by a stainless steel bladder that will be injected with urethane. The injection bladder will provide cooling passages during cooldown as well as transmitting the Lorentz forces between the jacket and the case. The large self-equilibrating lobe-spreading forces on the magnets (29.10/sup 6/ lb, 127.0 MN) for the A-cell are reacted primarily through the thick 304 LN case into the external superstructure. The net Lorentz forces and the inertial forces on the magnet are reacted through support systems into the LLNL vacuum vessel structure
The Future of Women\u27s Studies (Continued)
from the CALIFORNIA STATE UNIVERSITY, CHICO
Women\u27s Studies at Chico developed from courses offered by women in their different departments, gathered to form a minor degree program in spring, 1973. Two specifically women\u27s studies courses were designed at that time: a team-taught Introduction to Women\u27s Studies (draws around 80 students a semester, changes women students\u27 expectations and horizons by projecting models of achieving women) and a Senior Research Seminar designed to integrate the students\u27 major and minor. Both are taught by the Women\u27s Studies Coordinator. Student demand has led to the development of new courses whose content received a great deal of student input: Women\u27s Health, Women in the Working World, Women in Art, Minority Women and the Re-Entry Program for Mature Women. There are now 20 courses offered through the Women\u27s Studies Program. Students are designing special degrees on the B.A. and M.A. level in areas such as Women and Counseling, Psychology and Art.
...from the CITY COLLEGE OF THE CITY UNIVERSITY OF NEW YORK...
...from FLORIDA INTERNATIONAL UNIVERSITY...
...from the JERSEY CITY STATE COLLEGE...
...from the UNIVERSITY OF MARYLAND...
...from UNIVERSITY OF MASSACHUSETTS/AMHERST...
...from the UNIVERSITY OF MINNESOTA...
...from the UNIVERSITY OF SOUTH FLORIDA..
Activation of Central Melanocortin Pathways by Fenfluramlne
D-fenfluramine (d-FEN) was once widely prescribed and was among the most effective weight loss drugs, but was withdrawn from clinical use because of reports of cardiac complications in a subset of patients. Discerning the neurobiology underlying the anorexic action of d-FEN may facilitate the development of new drugs to prevent and treat obesity. Through a combination of functional neuroanatomy, feeding, and electrophysiology studies in rodents, we show that d-FEN-induced anorexia requires activation of central nervous system melanocortin pathways. These results provide a mechanistic explanation of d-FEN\u27s anorexic actions and indicate that drugs targeting these downstream melanocortin pathways may prove to be effective and more selective antiobesity treatments
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