7,710 research outputs found
Thin film module electrical configuration versus electrical performance
The as made and degraded states of thin film silicon (TFS) based modules have been modelled in terms of series resistance losses. The origins of these losses lie in interface and bulk regions of the devices. When modules degrade under light exposure, increases occur in both the interface and bulk components of the loss based on series resistance. Actual module performance can thus be simulated by use of only one unknown parameter, shunt losses. Use of the simulation to optimize module design indicates that the current design of 25 cells per linear foot is near optimum. Degradation performance suggests a shift to approx. 35 cells to effect maximum output for applications not constrained to 12 volts. Earlier studies of energy based performance and tandem structures should be updated to include stability factors, not only the initial loss factor tested here, but also appropriate annealing factors
Condensation and Metastability in the 2D Potts Model
For the first order transition of the Ising model below , Isakov has
proven that the free energy possesses an essential singularity in the applied
field. Such a singularity in the control parameter, anticipated by condensation
theory, is believed to be a generic feature of first order transitions, but too
weak to be observable. We study these issues for the temperature driven
transition of the states 2D Potts model at . Adapting the droplet
model to this case, we relate its parameters to the critical properties at
and confront the free energy to the many informations brought by previous
works. The essential singularity predicted at the transition temperature leads
to observable effects in numerical data. On a finite lattice, a metastability
domain of temperatures is identified, which shrinks to zero in the
thermodynamical limit. ~Comment: 32 pages, 6 figures, Late
Three dimensional finite temperature SU(3) gauge theory in the confined region and the string picture
We determine the correlation between Polyakov loops in three dimensional
SU(3) gauge theory in the confined region at finite temperature. For this
purpose we perform lattice calculations for the number of steps in the
temperature direction equal to six. This is expected to be in the scaling
region of the lattice theory. We compare the results to the bosonic string
model. The agreement is very good for temperatures T<0.7T_c, where T_c is the
critical temperature. In the region 0.7T_c<T<T_c we enter the critical region,
where the critical properties of the correlations are fixed by universality to
be those of the two dimensional three state Potts model. Nevertheless, by
calculating the critical lattice coupling, we show that the ratio of the
critical temperature to the square root of the zero temperature string tension,
where the latter is taken from the literature, remains very near to the string
model prediction.Comment: 11 pages, 1 figure, 1 tabl
Modification of nuclear transitions in stellar plasma by electronic processes: K-isomers in 176Lu and 180Ta under s-process conditions
The influence of the stellar plasma on the production and destruction of
K-isomers is studied for the examples 176Lu and 180Ta. Individual
electromagnetic transitions are enhanced predominantly by nuclear excitation by
electron capture, whereas the other mechanisms of electron scattering and
nuclear excitation by electron transition give only minor contributions. It is
found that individual transitions can be enhanced significantly for low
transition energies below 100 keV. Transitions with higher energies above 200
keV are practically not affected. Although one low-energy transition in 180Ta
is enhanced by up to a factor of 10, the stellar transition rates from low-K to
high-K states via so-called intermediate states in 176Lu and 180Ta do not
change significantly under s-process conditions. The s-process nucleosynthesis
of 176Lu and 180Ta remains essentially unchanged.Comment: 10 pages, 10 figures, Phys. Rev. C, accepte
Baryon Masses in Partially Quenched Heavy Hadron Chiral Perturbation Theory
The masses of baryons containing a heavy quark are calculated to
next-to-leading order in partially quenched heavy hadron chiral perturbation
theory. Calculations are performed for three light flavors in the isospin limit
and additionally for two light non-degenerate flavors. The results presented
are necessary for extrapolating lattice QCD and partially quenched lattice QCD
calculations of the heavy hadron masses.Comment: 20 pages, 2 figures, RevTex
Advanced Cancer Patients\u27 Medical Decision-Making While Experiencing Financial Toxicity
Financial toxicity (FT) is the impact that out of pocket (OOP) costs of cancer care have on patients\u27 well-being, leading to lower quality of life, less compliance with prescribed therapy, and poorer outcomes, including increased mortality. The purpose of this study was to understand the impact of FT on advanced cancer patients\u27 lives and their health care decision-making. Fuzzy trace theory provided the framework for examining how patients use gist and verbatim when making health care decisions while experiencing FT. Gist refers to main ideas that are often infused with emotional overlays that people use to make risky decisions, while verbatim thinking involves the recall of precise facts and figures to make decisions. The research method was case study that included conducting 13 in-depth interviews, collecting artifacts, and scoring of FT using the Comprehensive Score for Financial Toxicity tool. Findings from two-cycle coding and cross-case analysis indicated that FT and OOP costs have significant impacts on patients\u27 lives and how they make decisions about their cancer care. Participants considered cost as a risk in cancer treatment decisions and encoded this information using verbatim rather than gist, which they used for other dimension of risk in these decisions. Participants reported they would decline care if OOP costs were high and FT was present. When OOP costs were low, participants relied on gist decision-making and generally followed their physicians\u27 recommendations. Findings may assist cancer experts who are investigating FT and its impact on cancer care as well as those who are developing support programs for patients who experience FT
Optimal fabrication processes for unidirectional metal-matrix composites: A computational simulation
A method is proposed for optimizing the fabrication process of unidirectional metal matrix composites. The temperature and pressure histories are optimized such that the residual microstresses of the composite at the end of the fabrication process are minimized and the material integrity throughout the process is ensured. The response of the composite during the fabrication is simulated based on a nonlinear micromechanics theory. The optimal fabrication problem is formulated and solved with non-linear programming. Application cases regarding the optimization of the fabrication cool-down phases of unidirectional ultra-high modulus graphite/copper and silicon carbide/titanium composites are presented
Metal Matrix Laminate Tailoring (MMLT) code: User's manual
The User's Manual for the Metal Matrix Laminate Tailoring (MMLT) program is presented. The code is capable of tailoring the fabrication process, constituent characteristics, and laminate parameters (individually or concurrently) for a wide variety of metal matrix composite (MMC) materials, to improve the performance and identify trends or behavior of MMC's under different thermo-mechanical loading conditions. This document is meant to serve as a guide in the use of the MMLT code. Detailed explanations of the composite mechanics and tailoring analysis are beyond the scope of this document, and may be found in the references. MMLT was developed by the Structural Mechanics Branch at NASA Lewis Research Center (LeRC)
Stereotypical risks and threats in the youth’s opinion (diachronic comparative aspect)
The paper reveals the structure of associative fields of words-stimuli "danger", "risk", "threat", fixed in 1988-90 (the materials of "Russian Association Dictionary") and in 2015 (the results of authors’ associative experiment). The obtained results demonstrate the structural stability of these fields diachronically on the one hand and explicit redistribution of "association vectors" within them on the other on
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