Thermoregulated gas transport through electrospun nanofiber membranes

Thermoregulation of gas transport using electrospun fiber membranes is demonstrated experimentally for the first time. The fiber membranes comprise three layers: a middle layer of electrospun polystyrene sandwiched between two outer layers of electrospun cellulose acetate mat as supports, bonded together by hot pressing. The electrospun polystyrene layer serves as a phase change material that blocks transport of gases though the membrane when the fibers de-vitrify. The membrane exhibited a reduction in oxygen flux at temperatures in excess of 140 °C. Using a blend of polysulfone and polystyrene resulted in an upward shift of the transition temperature to 250 °C. Modeling of transport was performed to estimate the impact of the morphological properties of the membranes such as tortuosity, fiber diameter, and porosity.Philip Morris Internationa

Void Formation Study of Flip Chip in Package Using No-Flow Underfill

©2008 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or distribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.DOI: 10.1109/TEPM.2008.2002951The advanced flip chip in package (FCIP) process using no-flow underfill material for high I/O density and fine-pitch interconnect applications presents challenges for an assembly process that must achieve high electrical interconnect yield and high reliability performance. With respect to high reliability, the voids formed in the underfill between solder bumps or inside the solder bumps during the no-flow underfill assembly process of FCIP devices have been typically considered one of the critical concerns affecting assembly yield and reliability performance. In this paper, the plausible causes of underfill void formation in FCIP using no-flow underfill were investigated through systematic experimentation with different types of test vehicles. For instance, the effects of process conditions, material properties, and chemical reaction between the solder bumps and no-flow underfill materials on the void formation behaviors were investigated in advanced FCIP assemblies. In this investigation, the chemical reaction between solder and underfill during the solder wetting and underfill cure process has been found to be one of the most significant factors for void formation in high I/O and fine-pitch FCIP assembly using no-flow underfill materials

Environmental and human factors drive the subtropical marine forests of Gongolaria abies-marina to extinction

Large brown macroalgae are foundational threatened species in coastal ecosystems from the subtropical northeastern Atlantic, where they have exhibited a drastic decline in recent years. This study describes the potential habitat of Gongolaria abies-marina, its current distribution and conservation status, and the major drivers of population decline. The results show a strong reduction of more than 97% of G. abies-marina populations in the last thirty years and highlight the effects of drivers vary in terms of spatial heterogeneity. A decrease in the frequency of high waves and high human footprint are the principal factors accounting for the long-term decline in G. abies-marina populations. UV radiation and sea surface temperature have an important correlation only in certain locations. Both the methodology and the large amount of data analyzed in this study provide a valuable tool for the conservation and restoration of threatened macroalgae.En prensa1,95

Physical therapy Consultation in the Emergency Department For Older adults With Falls: a Qualitative Study

OBJECTIVES: Little is known about current practices in consulting physical therapy (PT) in the emergency department (ED) for older adults with falls, a practice that can reduce fall-related ED revisits. This qualitative study aimed to understand perspectives of ED staff about ED PT consultation for older adults with falls and fall-related complaints, specifically regarding perceived value and associated challenges and strategies. METHODS: We performed focus groups and key informant interviews with emergency physicians, advanced practice clinicians, nurses, physical therapists, occupational therapists, and technicians who perform ED geriatric screenings. We used rapid qualitative analysis to identify common themes related to decisions to consult PT from the ED, perceived value of PT, and common challenges and strategies in ED PT consultation. RESULTS: Twenty-five participants in 4 focus groups and 3 interviews represented 22 distinct institutions with ED PT consultation available for older adults with falls. About two thirds of EDs represented relied on clinician gestalt to request PT consultation (n = 15, 68%), whereas one third used formal consultation pathways (n = 7, 32%). Participants valued physical therapists\u27 expertise, time, and facilitation of hospital throughput by developing safe discharge plans and contact with patients to improve outpatient follow-up. Common challenges included limited ED PT staffing and space for PT evaluations; strategies to promote ED PT consultation included advocating for leadership buy-in and using ED observation units to monitor patients and avoid admission until PT consultation was available. CONCLUSION: ED PT consultation for older adults with falls may benefit patients, ED staff, and hospital throughput. Uncertainty remains over whether geriatric screening-triggered consultation versus emergency clinician gestalt successfully identifies patients likeliest to benefit from ED PT evaluation. Leadership buy-in, designated consultation space, and formalized consultation pathways are strategies to address current challenges in ED PT consultation

Altered litter inputs modify carbon and nitrogen storage in soil organic matter in a lowland tropical forest

Soil organic matter (SOM) in tropical forests is an important store of carbon (C) and nutrients. Although SOM storage could be affected by global changes via altered plant productivity, we know relatively little about SOM stabilisation and turnover in tropical forests compared to temperate systems. Here, we investigated changes in soil C and N within particle size fractions representing particulate organic matter (POM) and mineral-associated organic matter (MAOM) after 13 years of experimental litter removal (L−) and litter addition (L+) treatments in a lowland tropical forest. We hypothesized that reduced nitrogen (N) availability in L− plots would result in N-mining of MAOM, whereas long-term litter addition would increase POM, without altering the C:N ratio of SOM fractions. Overall, SOM-N declined more than SOM-C with litter removal, providing evidence of N-mining in the L− plots, which increased the soil C:N ratio. However, contrary to expectations, the C:N ratio increased most in the largest POM fraction, whereas the C:N ratio of MAOM remained unchanged. We did not observe the expected increases in POM with litter addition, which we attribute to rapid turnover of unprotected SOM. Measurements of ion exchange rates to assess changes in N availability and soil chemistry revealed that litter removal increased the mobility of ammonium-N and aluminium, whereas litter addition increased the mobility of nitrate-N and iron, which could indicate SOM priming in both treatments. Our study suggests that altered litter inputs affect multiple processes contributing to SOM storage and we propose potential mechanisms to inform future work

Enhancing the Interpretive Reading and Analytical Writing of Mainstreamed English Learners in Secondary School: Results From a Randomized Field Trial Using a Cognitive Strategies Approach

In this study, 72 secondary English teachers from the Santa Ana Unified School District were randomly assigned to participate in the Pathway Project, a cognitive strategies approach to teaching interpretive reading and analytical writing, or to a control condition involving typical district training focusing on teaching content from the textbook. Pathway teachers learned how to use an on-demand writing assessment to help mainstreamed English learners understand, interpret, and write analytical essays. In Year 2, treatment effects were replicated on an on-demand writing assessment (d = .67) and showed evidence of transfer to improved performance on a standardized writing test (d = .10). The results underscore the efficacy of a cognitive strategies reading/writing intervention for mainstreamed English learners (ELs) in the secondary grades

Valence states and spin structure of spinel FeV2O4 with different orbital degrees of freedom

The electronic structure of spinel FeV2O4, which contains two Jahn-Teller active Fe and V ions, has been investigated by employing soft x-ray absorption spectroscopy (XAS), soft x-ray magnetic circular dichroism (XMCD), and nuclear magnetic resonance (NMR). XAS indicates that V ions are trivalent and Fe ions are nearly divalent. The signs of V and Fe 2p XMCD spectra are opposite to each other. It is found that the effect of the V 3d spin-orbit interaction on the V 2p XMCD spectrum is negligible, indicating that the orbital ordering of V t2g states occurs from the real orbital states and that the orbital moment of a V3+ ion is mostly quenched. NMR shows that V spins are canted to have a Yafet-Kittel-type triangular spin configuration

Regresión de las algas marinas en las Islas Canarias y en la costa atlántica de la Península Ibérica por efecto del cambio climático

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