1,187 research outputs found

    Method for copper staining of germanium crystals

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    Proper conditions for copper staining of germanium crystals include a low solution temperature of 3 degrees C, illumination of the sample by infrared light, and careful positioning of the light source relative to the sample so as to minimize absorption of the infrared light

    Amazon\u27s Superior Innovation: A Study of Amazon\u27s corporate structure, CEO, and reasons behind why it has become the most innovative company in today\u27s market.

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    Amazon is one of today’s most powerful companies. The convenience of Amazon.com and the hot new products that Amazon is creating has skyrocketed Amazon to the top of the list of successful and innovative businesses. Looking at Amazon from the outside in, the question of “What drives Amazon to be so successful?” stands out. First thoughts are answers like “CEO, Jeff Bezos” or “it’s ability to innovate”. Yes, those are certainly major factors in the success of a company of this stature, but it is more complex than that. This study will answer the question, “How does Jeff Bezos’ leadership style give him the ability to visualize the structure for success that he has implemented so well with Amazon?

    Entropy and Correlations in Lattice Gas Automata without Detailed Balance

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    We consider lattice gas automata where the lack of semi-detailed balance results from node occupation redistribution ruled by distant configurations; such models with nonlocal interactions are interesting because they exhibit non-ideal gas properties and can undergo phase transitions. For this class of automata, mean-field theory provides a correct evaluation of properties such as compressibility and viscosity (away from the phase transition), despite the fact that no H-theorem strictly holds. We introduce the notion of locality - necessary to define quantities accessible to measurements - by treating the coupling between nonlocal bits as a perturbation. Then if we define operationally ``local'' states of the automaton - whether the system is in a homogeneous or in an inhomogeneous state - we can compute an estimator of the entropy and measure the local channel occupation correlations. These considerations are applied to a simple model with nonlocal interactions.Comment: 13 pages, LaTeX, 5 PostScript figures, uses psfig. Submitted to Int. J. Mod. Phys.

    Freeze-out volume in multifragmentation - dynamical simulations

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    Stochastic mean-field simulations for multifragmenting sources at the same excitation energy per nucleon have been performed. The freeze-out volume, a concept which needs to be precisely defined in this dynamical approach, was shown to increase as a function of three parameters: freeze-out instant, fragment multiplicity and system size.Comment: Submitted to Eur. Phys. J. A - march 200

    Experiences with HPTN 067/ADAPT Study-Provided Open-Label PrEP Among Women in Cape Town: Facilitators and Barriers Within a Mutuality Framework.

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    Placebo-controlled trials of pre-exposure prophylaxis (PrEP) have reported challenges with study-product uptake and use, with the greatest challenges reported in studies with young women in sub-Saharan Africa. We conducted a qualitative sub-study to explore experiences with open-label PrEP among young women in Cape Town, South Africa participating in HTPN 067/Alternative Dosing to Augment Pre-Exposure Prophylaxis Pill Taking (ADAPT). HPTN 067/ADAPT provided open label oral FTC/TDF PrEP to young women in Cape Town, South Africa who were randomized to daily and non-daily PrEP regimens. Following completion of study participation, women were invited into a qualitative sub-study including focus groups and in-depth interviews. Interviews and groups followed a semi-structured guide, were recorded, transcribed, and translated to English from isiXhosa, and coded using framework analysis. Sixty of the 179 women enrolled in HPTN 067/ADAPT participated in either a focus group (six groups for a total of 42 participants) or an in-depth interview (n = 18). This sample of mostly young, unmarried women identified facilitators of and barriers to PrEP use, as well as factors influencing study participation. Cross-cutting themes characterizing discourse suggested that women placed high value on contributing to the well-being of one's community (Ubuntu), experienced a degree of skepticism towards PrEP and the study more generally, and reported a wide range of approaches towards PrEP (ranging from active avoidance to high levels of persistence and adherence). A Mutuality Framework is proposed that identifies four dynamics (distrust, uncertainty, alignment, and mutuality) that represent distinct interactions between self, community and study and serve to contextualize women's experiences. Implications for better understanding PrEP use, and non-use, and intervention opportunities are discussed. In this sample of women, PrEP use in the context of an open-label research trial was heavily influenced by underlying beliefs about safety, reciprocity of contributions to community, and trust in transparency and integrity of the research. Greater attention to factors positioning women in the different dynamics of the proposed Mutuality Framework could direct intervention approaches in clinical trials, as well as open-label PrEP scale-up
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