1,564 research outputs found
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Geothermal development plan: Cochise/Santa Cruz Counties
The Cochise/Santa Cruz Counties Area Development Plan evaluated the regional market potential for utilizing geothermal energy. The study identified three potential geothermal resource areas with potential for resource temperatures less than 90/sup 0/C (194/sup 0/F). Geothermal resources are found to occur near the towns of Willcox, San Simon, and Bowier. Population growth rates are expected to average three percent per year over the next 30 years in Willcox; Bowie and San Simon are expected to grow much slower. Regional employment is based on agriculture and copper mining, though future growth in trade, services and international trade is expected. A regional energy-use analysis is also included. Urban use, copper mining and agriculture are the principal water users in the region and substantial reductions in water use are anticipated in the future. The development plan also contains a section identifying potential geothermal energy users in the region. Geothermal energy utilization projections suggest that by the year 2000, geothermal energy might economically provide the energy equivalent of 3,250,000 barrels of oil per year to the industrial sector. In addition, geothermal energy utilization might help stimulate an agricultural and livestock processing industry
EdShare: towards sharing resources for learning and teaching at the University of Southampton
At the University of Southampton, in the UK, we have been developing the Research Repository (e-Prints Soton) since 2005, to showcase the research output and make it more accessible. As a significant next step, the University has taken the strategic decision to develop a repository for educational materials. In developing EdShare at Southampton, we are promoting a cultural shift to a more open and collaborative approach to scholarship as well as research.Successful implementation in such a context requires a lightweight and very simple approach to sharing content facilitated by web 2.0 functionality.<br/
Viscoelastic Phase Separation in Shear Flow
We numerically investigate viscoelastic phase separation in polymer solutions
under shear using a time-dependent Ginzburg-Landau model. The gross variables
in our model are the polymer volume fraction and a conformation tensor. The
latter represents chain deformations and relaxes slowly on the rheological time
giving rise to a large viscoelastic stress. The polymer and the solvent obey
two-fluid dynamics in which the viscoelastic stress acts asymmetrically on the
polymer and, as a result, the stress and the diffusion are dynamically coupled.
Below the coexistence curve, interfaces appear with increasing the quench depth
and the solvent regions act as a lubricant. In these cases the composition
heterogeneity causes more enhanced viscoelastic heterogeneity and the
macroscopic stress is decreased at fixed applied shear rate. We find steady
two-phase states composed of the polymer-rich and solvent-rich regions, where
the characteristic domain size is inversely proportional to the average shear
stress for various shear rates. The deviatoric stress components exhibit large
temporal fluctuations. The normal stress difference can take negative values
transiently at weak shear.Comment: 16pages, 16figures, to be published in Phys.Rev.
Recommended from our members
Evaluation of geothermal energy in Arizona. Arizona geothermal planning/commercialization team. Quarterly topical progress report, July 1-September 30, 1980
Progress is reviewed on the following: area development plans, evaluation of geothermal applications, continued evaluation of geothermal resources, engineering and economic analyses, technical assistance in the state of Arizona, the impact of various growth patterns upon geothermal energy development, and the outreach program. (MHR
A class of ansatz wave functions for 1D spin systems and their relation to DMRG
We investigate the density matrix renormalization group (DMRG) discovered by
White and show that in the case where the renormalization eventually converges
to a fixed point the DMRG ground state can be simply written as a ``matrix
product'' form. This ground state can also be rederived through a simple
variational ansatz making no reference to the DMRG construction. We also show
how to construct the ``matrix product'' states and how to calculate their
properties, including the excitation spectrum. This paper provides details of
many results announced in an earlier letter.Comment: RevTeX, 49 pages including 4 figures (macro included). Uuencoded with
uufiles. A complete postscript file is available at
http://fy.chalmers.se/~tfksr/prb.dmrg.p
Large-scale structural organization of social networks
The characterization of large-scale structural organization of social
networks is an important interdisciplinary problem. We show, by using scaling
analysis and numerical computation, that the following factors are relevant for
models of social networks: the correlation between friendship ties among people
and the position of their social groups, as well as the correlation between the
positions of different social groups to which a person belongs.Comment: 5 pages, 3 figures, Revte
Breast cancer and exposure to tobacco smoke during potential windows of susceptibility
Purpose: An association between smoking and breast cancer is unresolved, although a higher risk from exposure during windows of susceptibility has been proposed. The objective of this prospective study was to evaluate the association between tobacco smoke and breast cancer with a focus on timing of exposure, especially during early life. Methods: Sister study participants (n = 50,884) aged 35–74 were enrolled from 2003 to 2009. Women in the United States and Puerto Rico were eligible if they were breast cancer-free but had a sister with breast cancer. Participants completed questionnaires on smoking and environmental tobacco smoke (ETS) exposure. Cox regression was used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) for breast cancer risk. Results: During follow-up (mean = 6.4 years), 1,843 invasive breast cancers were diagnosed. Neither active smoking nor adult ETS was associated with breast cancer risk. However, never smoking women exposed to ETS throughout their childhood had a 17% higher risk of breast cancer (95% CI 1.00–1.36) relative to those with no exposure. In utero ETS exposure was also associated with breast cancer (HR = 1.16, 95% CI 1.01–1.32) and the HR was most elevated for women born in earlier birth cohorts (<1940, HR = 1.44, 95% CI 1.02–2.02; 1940–1949, HR = 1.28, 95% CI 1.01–1.62). Conclusion: In utero ETS and ETS exposure during childhood and adolescence were associated with increased risk of breast cancer and associations varied by birth cohort
Phase Diagram of a Spin Ladder with Cyclic Four Spin Exchange
We present the phase diagram of the Heisenberg model on the two leg
ladder with cyclic four spin exchange, determined by a combination of Exact
Diagonalization and Density Matrix Renormalization Group techniques. We find
six different phases and regimes: the rung singlet phase, a ferromagnetic
phase, two symmetry broken phases with staggered dimers and staggered scalar
chiralities, and a gapped region with dominant vector chirality or collinear
spin correlations. We localize the phase transitions and investigate their
nature.Comment: 4 pages, 6 figures, REVTeX 4, published versio
Women, men and coronary heart disease: a review of the qualitative literature
Aim. This paper presents a review of the qualitative literature which examines the experiences of patients with coronary heart disease. The paper also assesses whether the experiences of both female and male patients are reflected in the literature and summarizes key themes.
Background. Understanding patients' experiences of their illness is important for coronary heart disease prevention and education. Qualitative methods are particularly suited to eliciting patients' detailed understandings and perceptions of illness. As much previous research has been 'gender neutral', this review pays particular attention to gender.
Methods. Published papers from 60 qualitative studies were identified for the review through searches in MEDLINE, EMBASE, CINAHL, PREMEDLINE, PsychINFO, Social Sciences Citation Index and Web of Science using keywords related to coronary heart disease.
Findings. Early qualitative studies of patients with coronary heart disease were conducted almost exclusively with men, and tended to generalize from 'male' experience to 'human' experience. By the late 1990s this pattern had changed, with the majority of studies including women and many being conducted with solely female samples. However, many studies that include both male and female coronary heart disease patients still do not have a specific gender focus. Key themes in the literature include interpreting symptoms and seeking help, belief about coronary 'candidates' and relationships with health professionals. The influence of social roles is important: many female patients have difficulties reconciling family responsibilities and medical advice, while male patients worry about being absent from work.
Conclusions. There is a need for studies that compare the experiences of men and women. There is also an urgent need for work that takes masculinity and gender roles into account when exploring the experiences of men with coronary heart disease
The Sachs-Wolfe Effect: Gauge Independence and a General Expression
In this paper we address two points concerning the Sachs-Wolfe effect: (i)
the gauge independence of the observable temperature anisotropy, and (ii) a
gauge-invariant expression of the effect considering the most general situation
of hydrodynamic perturbations. The first result follows because the gauge
transformation of the temperature fluctuation at the observation event only
contributes to the isotropic temperature change which, in practice, is absorbed
into the definition of the background temperature. Thus, we proceed without
fixing the gauge condition, and express the Sachs-Wolfe effect using the
gauge-invariant variables.Comment: 5 pages, closer to published versio
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