13,720 research outputs found

    New method for photoresist stripping

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    Vacuum dehydration of negatively working photoresist eliminates trace contamination of conventional stripping methods. The semiconductor substrate is coated with photoresist, exposed, developed, cured, and etched, and then placed in a vacuum. Following dehydration, the resist film is removable with ordinary solvents

    Integral Glass Encapsulation for Solar Arrays

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    Work reported was performed during the period from August 1977 to December 1978. The program objective was to continue the development of electrostatic bonding (ESB) as an encapsulation technique for terrestrial cells. Economic analyses shows that this process can be a cost-effective method of producing reliable, long lifetime solar modules. When considered in sufficient volume, both material and equipment costs are competitive with conventional encapsulation systems. In addition, the possibility of integrating cell fabrication into the encapsulation process, as in the case of the preformed cell contacts discussed in this report, offers the potential of significant overall systems cost reduction

    Third sector organizations and earthquake recovery planning in Christchurch, New Zealand

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    On September 4, 2010, an earthquake struck rural Canterbury and the most deadly of over 2,000 aftershocks devastated the Christchurch Central Business District on February 22, 2011 (Ardagh et al. 2012). Questions have arisen regarding population dynamics (Love 2011), marginalized groups, health and social care, and overall recovery efforts. Addressing some of these concerns are various non-profit, non-governmental, and faith based groups, collectively referred to as Third Sector Organizations (TSOs). By providing an alternative to and back-stopping government and private health and social services, TSOs are able to build resiliency following a natural disaster, and are especially able to identify and address unmet needs within their target audiences and maintain a sense of community within their operating areas. The nature of community recovery, also changes the role of TSOs in formal and grassroots efforts over time. In New Zealand, TSOs have shared community health burdens with government and private practices since the 1990s (Larner and Craig 2005) and have championed healthcare policy measures for ethnic minorities (Came 2014). Nevertheless, the earthquakes have presented challenges to TSOs. An inventory of 92 TSOs four months after the earthquakes, 106 one year after, and 454 two years after by Carlton and Vallance (2013) shows that although many TSOs have emerged to address earthquake related issues, other TSOs may have been unable to re-establish themselves outside areas with earthquake damage found to be too severe to inhabit by the Canterbury Earthquake Recovery Authority (CERA). Others reported “burn-out” and 52 were inactive or closed because of shifting needs during recovery. This research identifies shared experiences across the third sector in Canterbury to illuminate shifting roles in mid to long-term earthquake recovery

    Engaging youth in post-disaster research: Lessons learned from a creative methods approach

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    Children and youth often demonstrate resilience and capacity in the face of disasters. Yet, they are typically not given the opportunities to engage in youth-driven research and lack access to official channels through which to contribute their perspectives to policy and practice during the recovery process. To begin to fill this void in research and action, this multi-site research project engaged youth from disaster-affected communities in Canada and the United States. This article presents a flexible youth-centric workshop methodology that uses participatory and arts-based methods to elicit and explore youth’s disaster and recovery experiences. The opportunities and challenges associated with initiating and maintaining partnerships, reciprocity and youth-adult power differentials using arts-based methods, and sustaining engagement in post-disaster settings, are discussed. Ultimately, this work contributes to further understanding of the methods being used to conduct research for, with, and about youth.Keywords: youth, disaster recovery, engagement, resilience, arts-based methods, participatory researc

    Predicted Colors and Flux Densities of Protostars in the Herschel PACS and SPIRE Filters

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    Upcoming surveys with the Herschel Space Observatory will yield far-IR photometry of large samples of young stellar objects, which will require careful interpretation. We investigate the color and luminosity diagnostics based on Herschel broad-band filters to identify and discern the properties of low-mass protostars. We compute a grid of 2,016 protostars in various physical congurations, present the expected flux densities and flux density ratios for this grid of protostars, and compare Herschel observations of three protostars to the model results. These provide useful constraints on the range of colors and fluxes of protostar in the Herschel filters. We find that Herschel data alone is likely a useful diagnostic of the envelope properties of young starsComment: Part of HOPS KP papers to the Herschel special A&A issu

    Demographic characteristics and association of serum Vitamin B12, ferritin and thyroid function with premature canities in Indian patients from an urban skin clinic of North India: A retrospective analysis of 71 cases

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    yesBackground: The incidence of self-reported premature hair graying (PHG) seems to be on the rise. PHG has a profound impact on the patient's quality of life. It remains an incompletely understood etiology with limited and modest treatment options. Aim: The evaluation of the demographic and clinical profile of patients with premature canities, and exploration of the association of this entity with certain systemic disorders suspected to be related to its etiology. Methods: Seventy-one cases of premature canities (onset noticed by patients before 25 years of age) presenting to an urban skin clinic in Gurugram, India, between September 2012 and September 2015 with this complaint were retrospectively analyzed. The patient records were retrieved that provided details of the onset, duration and pattern of involvement, history, and examination findings (scalp, cutis, and general physical). Since all these patients had been screened for anemia, thyroid disorder, fasting blood glucose, and Vitamin B12 levels at the time of presentation, these parameters were also available for analysis. Results: The mean age at onset of graying was 10.2 ± 3.6 years (range: 5–19 years), with an almost equal gender distribution. The earliest age of onset recorded was 5 years. A positive family history of PHG (at least one of the biological parents or siblings) was obtained in 64 (90.1%) of the cases. The temporal regions of the scalp (35.2%) were most commonly involved followed by the frontal region (18.3%). Hypovitaminosis B12 and hypothyroidism showed significant association with the disorder, whereas anemia, serum ferritin, and fasting blood glucose did not. Conclusion: The age of onset of hair graying can be as low as 5 years. Temporal and frontal areas are the most commonly involved sites. A strong family history, Vitamin B12 deficiency, and hypothyroidism are strongly associated with PHG. Larger case–control studies are mandated for discerning the correlation of these and other risk factors with PHG

    Cryptography using evolutionary computing

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    We present a method of generating encryptors, in particular, Pseudo Random Number Generators (PRNG), using evolutionary computing. Working with a system called Eureqa, designed by the Cornell Creative Machines Lab, we seed the system with natural noise sources obtained from data that can include atmospheric noise generated by radio emissions due to lightening, for example, radioactive decay, electronic noise and so on. The purpose of this is to `force' the system to output a result (a nonlinear function) that is an approximation to the input noise. This output is then treated as an iterated function which is subjected to a range of tests to check for potential cryptographic strength in terms of a positive Lyapunov exponent, maximum entropy, high cycle length, key diffusion characteristics etc. This approach provides the potential for generating an unlimited number of unique PRNG that can be used on a 1-to-1 basis. Typical applications include the encryption of data before it is uploaded onto the Cloud by a user that is provided with a personalised encryption algorithm rather than just a personal key using a `known algorithm' that may be subject to a `known algorithm attack' and/or is `open' to the very authorities who are promoting its use

    High efficiency GaAs-Ge tandem solar cells grown by MOCVD

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    High conversion efficiency and low weight are obviously desirable for solar cells intended for space applications. One promising structure is GaAs on Ge. The advantages of using Ge wafers as substrates include the following: they offer high efficiency by forming a two-junction tandem cell; low weight combined with superior strength allows usage of thin (3 mil) wafers; and they are a good substrate for GaAs, being lattice matched, thermal expansion matched, and available as large-area wafers

    Probing 5f-state configurations in URu2Si2 with U L3-edge resonant x-ray emission spectroscopy

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    Resonant x-ray emission spectroscopy (RXES) was employed at the U L3 absorption edge and the La1 emission line to explore the 5f occupancy, nf, and the degree of 5f orbital delocalization in the hidden order compound URu2Si2. By comparing to suitable reference materials such as UF4, UCd11, and alpha-U, we conclude that the 5f orbital in URu2Si2 is at least partially delocalized with nf = 2.87 +/- 0.08, and does not change with temperature down to 10 K within the estimated error. These results place further constraints on theoretical explanations of the hidden order, especially those requiring a localized f2 ground state.Comment: 11 pages,7 figure
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